UNITED24 - Make a charitable donation in support of Ukraine!

Weapons of Mass Destruction (WMD)

Previous PageTable Of ContentsList Of FiguresList Of TablesNext Page

4.14 HUMAN HEALTH


4.14.1 Affected Environment

This section addresses the sources of radioactivity and toxic chemicals at Pantex Plant and their effects on human health and the environment. The section also addresses the plants vulnerability to accidents associated with these sources. Appendix D, Human Health Analysis, in volume II contains additional information.

The potential release of radioactivity and toxic chemicals to the environment from a DOE facility is an important issue for onsite workers and the public. Since the human environment contains many sources of radioactivity and toxic chemicals, it is essential to understand the sources of these substances and how effectively they are controlled.

Beyond radiation, chemical, and explosive hazards, workers involved with facility operations are exposed to common industrial workplace hazards (e.g., mechanical or electrical hazards). Adequate worker safety from these common industrial workplace hazards is furnished through compliance with the Occupational Safety and Health Act of 1990 (5 U.S.C. 5108); and 29 CFR 1910, "Occupational Safety and Health Standards." As discussed in section 4.14.1.4, incidence rates at Pantex Plant are below national averages for general and manufacturing industries.

Exposure from inhalation is the overwhelmingly risk-significant pathway for public exposure. It bounds the risk in the assessment of chemical and radiological airborne hazards from normal operations. For accident scenarios involving the release of tritium, skin absorption of tritium oxide is accounted for since it represents about 50 percent of the dose of inhalation (DOE 1991). Inhalation remains the dominant pathway for all other releases.

In the case of a radioactive materials release, radiation doses to individuals result from immediate exposure to the passing radioactive material plume and from long-term exposure to radioactive material deposited in the environment during the plume passage. The dominant exposure pathway for cloud passage for plutonium accidents is inhalation. Plutonium does not readily absorb through the skin, and any ingestion of plutonium from the passing plume is minimal when compared with inhalation.

The long-term accumulation of doses to individuals affected by a radioactive material release could occur from (1) direct doses from groundshine and resuspension inhalation (inhalation dose from inhaling resuspended particles from the ground), (2) ingestion of food crops and milk produced from contaminated ground, and (3) ingestion of contaminated water. Independent of mitigative actions, both the magnitude of long-term doses and the relative importance between pathways is dependent on both the chemical and radiological behavior of the material released to the environment. The chemical nature of plutonium oxide decreases the importance of the ingestion pathways relative to inhalation. Plutonium oxide does not readily absorb into the body when ingested (PNL 1988). As such, the main health risk from plutonium oxide occurs when very small particles are inhaled and become lodged in the lungs.

Historical pathway analysis and dose reconstruction have clearly shown that inhalation is the dominant pathway for plutonium risk. The 1983 Pantex EIS (DOE 1983a) found that after a dispersal accident, over 95 percent of the total plutonium exposure is from inhalation, assuming no remediation or cleanup. With cleanup, over 99 percent of the estimated total plutonium exposure is from inhalation. The Rocky Flats dose reconstruction project analyzed the health impact of historical plutonium emissions from the Rocky Flats Plant and concluded that the only significant pathway, again without remediation or cleanup, for plutonium exposure is inhalation (ChemRisk 1994). Thus, the dominant risk pathway for plutonium dispersal accidents at Pantex Plant is the inhalation pathway.

The Federal government is required under the Federal Radiological Emergency Response Plan (61 FR 20944) to respond to a radiological emergency and provide resources to assist in the evaluation and mitigation of potential long-term exposure pathways to humans. Specifically, the agencies listed below will provide resources to perform specific functions following an accidental release. The Environmental Protection Agency (EPA) will assume responsibility from DOE for long-term monitoring and remediation following an accident. EPA will assist in the preparation of area restoration plans and will recommend cleanup criteria.

The Department of Agriculture (USDA) will inspect meat and meat products, poultry and poultry products, and egg products to assure that they are safe for human consumption. In addition, USDA, in conjunction with the Department of Health and Human Services (HHS), will assist in monitoring the production, processing, storage, and distribution of food through the wholesale level to eliminate contaminated product and in reducing the contamination in the product to a safe level. HHS will assist with the assessment, preservation, and protection of human health, and will assist State and local government officials in making evacuation and relocation decisions.

Figure 4.14.11 depicts the offsite population within an 80-kilometer (50-mile) radius of Pantex Plant, known as the Region of Influence (ROI) (UN 1995). The highest population density occurs southwest of Pantex Plant. Wind speeds and directions in the Pantex Plant vicinity are presented in Figure 4.7.1.11. The wind blows predominately from the south from May to September and from the southwest for the remainder of the year.


4.14.1.1 Radiation Environment

Table 4.14.1.11 summarizes the major sources of radiation exposure in the vicinity of Pantex Plant (NCRP 1987). Releases from Pantex Plant operations constitute a very small fraction of the total exposure to the public in the vicinity of the plant. Cancer statistics for the State of Texas indicate that annually, a person in the Pantex Plant vicinity has a 1.7 x 10-3 probability of contracting a fatal cancer. From examining nominal fatal cancer risk factors for the public and Table 4.14.1.11 data, it can be seen that fatal cancers attributable to environmental radioactivity released from Pantex Plant constitute an extremely small fraction (less than 0.01 percent) of the average yearly fatal cancer probability in the vicinity of Pantex Plant (DOE 1994l:4-20).

The majority of Pantex Plant workers receive no detectable radiation exposures (i.e., zero dose) during normal operations as a result of their work and are considered non-involved workers. Of those workers that received non-zero doses (involved workers total 329) over the last 5 years, the average annual dose was 111 millirem with a maximum individual dose of 0.905 rem (Pantex 1996a). These exposures were in addition to exposures received from background sources described in Table 4.14.1.11. DOE Order 5480.11 and 10 CFR 835 specify a limit of 5 rem per year for occupational workers. In addition, as of 1996, the Pantex Plant administrative control level is 500 millirem per year for most workers and 900 millirem per year for production (weapons operations) workers.

Figure 4.14.1-1.--Population Within 80 kilometers (50 miles) of Pantex Plant.

Table 4.14.1.1-1.--Major Sources of Radiation Exposure in the Vicinity of Pantex Plant (.pdf)

The plant plans to continue to reduce the control level for production workers to the 500 millirem per year level. Using fatal cancer risk factors for workers, the average annual probability of a Pantex Plant worker contracting a fatal cancer due to occupational radiation exposure is 4.4 x 10-5. For those Pantex Plant workers that receive radiation doses, this 4.4 x 10-5 value is essentially in addition to the average annual fatal cancer risk of 1.7 x 10-3 for the regional population.

The largest contributors to worker radiological doses at Pantex Plant are external exposures (i.e., those received from radiation-emitting sources). The largest potential for external doses occurs from weapon operations and pit repackaging. Worker population dose, from an external exposure viewpoint, has been significantly reduced at Pantex Plant due to improvements in work practices and changes in work scope. In 1980, Pantex Plant operations resulted in a cumulative worker dose of 148 person-rem over 719 personnel. In 1994, Pantex Plant operations resulted in a cumulative worker dose of 29 person-rem over 329 personnel (Pantex 1996a).

Internal exposures, received when radioactive materials are deposited through inhalation, ingestion, or absorption, are only minor contributors to worker doses. During normal operations, engineering controls (e.g., confinement and ventilation) are the primary methods of controlling airborne concentrations of radionuclides and minimizing internal exposure. Administrative controls (e.g., exposure limits and procedural requirements) and personnel protective equipment (e.g., respirators) are used as supplemental methods to control internal radiation exposure. The largest single source of internal exposures was from the contamination of Building 1244 Cell 1 with tritium in 1989; the result was a total worker dose of approximately 1.5 person-rem, with a maximum individual dose of 1.3 rem.

The Pantex Radiological Control Manual (Pantex 1996d) establishes site-specific guidelines and procedures to minimize or eliminate radiological exposure and risk to workers while performing work involving radioactive materials and radiationgenerating devices. The Pantex Plant manual is based on the requirements contained in the DOE Radiological Control Manual (DOE 1992); 10 CFR 835, Occupational Radiation Protection; and DOE Order 5480.11, Radiation Protection for Occupational Workers.

The "As Low As Reasonably Achievable" (ALARA) program at Pantex Plant is another control to help limit the number of personnel occupational exposures and public/environmental exposures to radioactive material. This program applies to all plant facilities, equipment, processes, and operations involving a potential or actual exposure of personnel to ionizing radiation, and is based on the regulations discussed above.


4.14.1.2 Chemical Environment

Hazardous chemicals are used in the performance of certain Pantex Plant operations. A full listing of hazardous chemicals used at Pantex Plant is provided in the Pantex Plant Safety Information Document (Pantex 1996a). Pantex Plant operations that require the use of hazardous chemicals are performed in full compliance with Occupational Safety and Health Administration (OSHA)Occupational Safety and Health Administration (OSHA) regulations and American Conference of Government Industrial Hygienists guidelines.

Under normal operations, various chemicals are released to the air that have the potential to impact the public. Table 4.14.1.21 lists the hazardous air pollutants released to the air and their calculated maximum potential concentrations at the plant fence line (see section 4.7, Air Quality). The concentrations were calculated with the EPA-approved ISCST2ISCST2 and ISCLT2ISCLT2 codes (see volume II, appendix B) using existing Pantex Plant sources (PC 1994). Emission inventories used here also apply for the 2,000 weapons activity level. Effects Screening Levels (ESL)Effects screening levels (ESLs) from Texas Natural Resource Conservation Commission (TNRCC)TNRCC are also listed in the table and used for comparison.

A useful measure of potential human health effects resulting from exposure to non-carcinogenic chemicals is the hazard index. In its most general form, a hazard index is a ratio of the actual exposure of a human receptor to an established exposure limit. If this ratio is appreciably less than unity, no adverse human health effects are expected. If the hazard index is close to unity, some adverse human health effects may occur; and if the hazard index is substantially greater than unity, severe health effects can results. Table 4.14.1.22 presents the individual hazard quotients, which summed together make up the hazard index. The hazard index for chemicals released from Pantex Plant is 0.0909. That is an order of magnitude less than 1.0, and no adverse health effects are expected.

Within the plant boundary, calculated concentrations are somewhat higher. They are, however, below exposure limits established by OSHA and considered safe from adverse noncancer effects. Table 4.14.1.23 shows a comparison between maximum onsite concentrations and allowable exposure limits.

Some toxic chemicals are also carcinogenic. Table 4.14.1.24 gives the available chemical risk factors for those pollutants that are carcinogens (except for lead, which does not have an available risk factor). When combined with chemical concentrations and human exposures (e.g. the amount of time an individual is in contact with the chemical), it is possible to calculate a latent cancer probability. It was assumed that exposure to the public was entirely from inhalation, since airborne transport is the only viable pathway to the public. Using the calculated concentrations in Table 4.14.1.21, toxic chemical emissions would result in a probability of 1.2 x 10-5 that a hypothetical individual living at the plant boundary would contract a latent cancer.

Table 4.14.1.2-1.-- Maximum Estimated Fence Line Concentration of Air Pollutants Resulting from Existing Pantex Plant Sources (.pdf)

Table 4.14.1.2-2.--Hazard Quotient for Concentrations Resulting from Existing Pantex Plant Sources (.pdf)

Table 4.14.1.2-3.--Maximum Potential Onsite Ambient Concentration of Pollutants Resulting from Existing Pantex Plant Sources (.pdf)

Table 4.14.1.2-4.--Chemical Risk Factors (.pdf)


4.14.1.3 Health Effects Studies

A June 1994 study by the Texas Cancer Registry, Texas Department of Health, showed significant increases in prostate cancer mortality among males in Potter and Randall Counties and leukemia mortality among Carson County males during the period 19811992. There were no statistically significant increases observed in site-specific cancer mortality among females during this period. For cancer incidence during the period 19861992, no statistically significant excesses in males were seen; however, cancer of the prostate was slightly elevated in males in Potter and Randall Counties. Analysis of the four major cell-specific types of leukemia showed a significant excess in the incidence of chronic lymphocytic leukemia among Potter and Randall Counties females. This cursory study was conducted in Carson, Potter, and Randall Counties, which are located near Pantex Plant. This study focused only on cancers of the breast, prostate, brain, thyroid, and leukemia, which were of specific concern to citizens in the area. Other radiation-associated cancers, such as bone and lung, were not included in this study. Although prostate cancer and chronic lymphocytic leukemia have not been linked to radiation exposure, further followup to this study was recommended.

An epidemiologic study of past and present Pantex Plant workers was done and published in the Health Physics Journal (Acquavella 1985). This study compared total and cause-specific mortality for Pantex Plant workers employed between 1951 and December 31, 1978, with expected cause-specific mortalities based on U.S. death rates. Significantly fewer deaths were observed in the workforce than would be expected from projections based on U.S. death rates for the following causes of death: all cancers, arteriosclerotic heart disease, and digestive diseases. Furthermore, no specific causes of death occurred significantly more frequently than expected. Slightly elevated mortality ratios were observed for brain cancer and leukemia; neither excess was statistically significant. The four deaths from brain cancer all occurred among those who had worked at the plant less than 5 years. The four deaths from leukemia occurred with equal frequency among those who had worked at the plant a short time and those who had worked over 15 years.

DOE Headquarters Office of Epidemiological Studies initiated an epidemiologic surveillance program at Pantex Plant in 1993 in order to address the current health status of the workforce. This program tracks and analyzes the occurrence of illness and injury on a continuing basis. Monthly data collection began on January 1, 1994; data and reports will be issued on a semiannual basis. These reports provide an ongoing assessment of any health problems that may be associated with Pantex Plant operations. The Pantex 1994 annual report is available.

A followup of the 1985 mortality study of the Pantex Plant workforce is planned. The update will be conducted by the National Institute for Occupational Safety and Health as part of a research program funded by DOE under a Memorandum of Understanding with the Department of Health and Human Services. The followup study by the National Institute for Occupational Safety and Health is scheduled to commence either in late 1996 or early 1997. The study will provide additional years of data on the mortality experience of Pantex Plant workers.

Table 4.14.1.4-1.--Comparison of Incidence Rates for Pantex Plant and Industry (.pdf)


4.14.1.4 Accident Mitigation

Yearly incidence rates provide an objective performance measure of Pantex Plant safety programs. The data in Table 4.14.1.41 can be used to compare the performance of Pantex Plant operations to that of the general, manufacturing, and chemical industries nationally; the table demonstrates that Pantex Plant safety programs tend to be more effective. For both total recordable cases and lost workday cases, incidence rates at Pantex Plant are below industrial averages, with the exception of lost workdays, where Pantex Plant exceeds chemical industry incidence rates.

To minimize worker radiation and chemical exposures, a number of mitigation measures are in place at Pantex Plant. These measures reflect an overall defense-in-depth safety philosophy to prevent or minimize potential releases from internal or external initiating events. Essentially, this philosophy imposes multiple barriers between sources of radiation and the public. Typically at Pantex Plant, three separate types of barriers are imposed: cladding, packaging, and plant facilities. Cladding refers to the actual material covering radionuclides. Metallic pit cladding is used for the plutonium in pits. For tritium, the effective cladding is the reservoir. Though not completely passive, the only active component found on some tritium reservoirs is a small explosive squib that operates the valve mechanism used to release the tritium from the reservoir. Protective covers are installed over the squibs which include shorting plugs and/or shunts. These plugs and shunts provide protection against accidental firing of the squib.

The plutonium in Radioisotopic Thermoelectric Generator (RTG) radioisotopic thermoelectric generators has an exceptionally robust cladding designed to withstand high pressures and temperatures. Tests of radioisotopic thermoelectric generators have demonstrated their ability to withstand an exposure of 1,000 ûC (1,832 ûF) for 1 hour.

Packaging refers to the containers used for transporting and staging the clad radionuclides. The use of these qualified protective containers, when special operations are not being performed, is an important aspect of minimizing the frequency of operational accidents that could result in the release of radioactive materials.

In the unlikely event that cladding and packaging should be breached, the facilities themselves serve as the final barrier for the defense-in-depth philosophy. Regarding releases of radionuclides from the cells, where a large part of the operations take place, steel blast doors protect the equipment passageway and are expected to remain intact and closed. The blast valves in the intake and exhaust air supply ducts, as well as the contaminated waste isolation valve system, prevent radioactive particles from escaping through these pathways.

Within the bays, any accident involving a breach of cladding integrity will shut down the heating, ventilating, and air conditioning through the Radiation Alarm Monitoring System interlock upon detection of alpha radiation, thus limiting the potential contamination to the bay of occurrence. Building 1264 is an exception because it does not have the interlock. The impact of this exception is accounted for in the evaluation of potential accident scenarios. Upon detection of tritium (beta radiation), an exhaust will ventilate the tritium to the atmosphere. The design features of buildings provide other barriers that prevent the dispersal of plutonium during accidents. The building features also reduce the probability of damage to the facility from natural phenomena and external events (e.g., earthquakes and tornadoes).

Structural analysis performed on buildings representative of Pantex Plant construction types shows that heavily reinforced structures are not vulnerable to damage from large scale tornadoes. Fire was identified as a possible release scenario. However, a fire limited to the interior of the facility by the fire suppression system or the fire fighters would only cause internal releases in the room of the fire. Where applicable, the high efficiency particulate air filters could prevent release to the exterior atmosphere.

Besides the systems and structures noted above, numerous other features serve to enhance facility safety. These features include:

  • Rad-safe systems (radiation detection and alarm systems) and continuous air monitors to protect personnel from radiological exposure.
  • Fire protection systems.
  • Grounding and lightning protection systems.
  • Electrical power stability, including an uninterruptible power supply and emergency lighting.
  • An emergency communication system to notify personnel and provide quick response to accidents, adverse weather, or natural disaster.

The defense-in-depth philosophy summarized above emphasizes physical barriers. In addition to these physical barriers, Pantex Plant also employs numerous administrative controls that minimize the likelihood of operator errors.

Pantex Plant has numerous integrated programs that work together to establish and maintain "barriers" to protect the public, the workers, and the environment. Programs of this type include the SAR (Safety Analysis Report) Program that defines the safety envelope for each facility, establishes the required and allowable facility configurations, and formally authorizes facility operations. Similarly, the HAR (Hazards Assessment Report) Program serves to evaluate and authorize individual operations which are conducted within the aforementioned facilities.

Once facility configurations and operational procedures are established by the SARs and HARs, programs such as Configuration Management, Conduct of Operations, Maintenance Management, USQ (Unreviewed Safety Question) Program, and the Change Control Board serve to continually ensure that facilities are maintained and operations are conducted as authorized. In the event that any facility or operation is found to be out of compliance with the authorized safety basis, immediate steps are taken to correct the deficiency. A determination is made whether or not to continue operations. Facilities or procedures may be modified to allow continued operations while the deficiency is being corrected. Additional programs, which work together to establish and maintain safety at Pantex Plant, include the following:

  • Nuclear Safety Management
  • Operational Readiness Reviews
  • Radiation Safety
  • Nuclear Explosives Safety

Information on these programs is presented in the Program Information Document and the Safety Information Document.


4.14.1.5 Compliance with Occupational Safety and Health Requirements

The health and safety of all workers associated with Pantex Plant operations is a primary consideration in the decision resulting from this EIS. A comprehensive nuclear and occupational safety and health initiative was announced by the Secretary on May 5, 1993, entailing closer consultation with Occupational Safety and Health Administration (OSHA)OSHA regarding regulation of worker safety and health at DOE contractor-operated facilities. Regulation of worker health and safety at DOE contractor-operated facilities will gradually shift from DOE to OSHA.

The Occupational Safety and Health Act of 1970 (Public Law 91-596) establishes Federal requirements for assuring occupational safety and health protection for employees. DOE and OSHA have agreed to a temporary pilot project to facilitate the shift of worker protection to OSHA. Under this temporary pilot project, OSHA will regulate and oversee worker health and safety at the Argonne National Laboratory in DuPage, Illinois. During the pilot, OSHA will evaluate the current safety and health program at Argonne and respond to employee complaints.

Information obtained during the Argonne pilot project is expected to help the two agencies determine the resource needs of OSHA if it is to ultimately assume responsibility for worker safety and health at DOE facilities. While OSHA regulates and enforces worker health and safety at industrial and some government workplaces, current law exempts most DOE facilities from external regulation and enforcement. DOE internal regulations do, however, require all facilities to meet current OSHA standards.

DOE facilities also comply with the Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11001), which requires facilities to report the release of extremely hazardous substances and other specified chemicals; provide material safety data sheets or lists thereof; and provide estimates of the amounts of hazardous chemicals onsite. The reporting and emergency preparedness requirements are designed to protect both individuals and communities.

Workplace Safety and Accidents

Operations at Pantex Plant expose workers to occupational hazards during the normal conduct of their work activities. Occupational safety and health training that includes specialized job safety and health training appropriate to the work performed is provided for all employees at Pantex Plant. This training also includes informing employees of their rights and responsibilities under the Occupational Safety and Health Act of 1970; Executive Order 12196, which established OSHA Federal Agency Standards; 29 CFR 1960The OSHA Federal Agency Standardswhich describes the safety and health programs that Federal agencies must establish and implement under Executive Order 12196; and DOE Order 440.1Federal Employee Occupational Safety and Health Program. DOE provides implementation guidance in DOE Order 440.1, including the requirements and guidelines for the DOE Federal Employee Industrial Hygiene Program. DOE policy is to:

  • Provide places and conditions of employment that are as free as possible from recognized hazards that cause or are likely to cause illness or physical harm.
  • Assure that employees and employee representatives have the opportunity to participate in the Federal Employee Occupational Safety and Health Program.
  • Establish programs in safety and health training for all levels of Federal employees.
  • Consider the 29 CFR 1960 (OSHA Standards for Federal Agencies) requirements to be the minimum standards for DOE employees.

DOE contractor operations at Pantex Plant expose workers to hazardous constituents. DOE orders require that site operations have programs for protection of workers. DOE Orders 5480.11, Radiation Protection for Occupational Workers, and 440.1, Federal Employee Occupational Safety and Health Appraisal Program, establish procedures for protection of workers against radiological and hazardous materials, respectively. DOE Order 232.1, Occurrence Reporting and Processing of Operations Information, provides for reporting and guides appropriate corrective action(s) and follow-up should an exposure occur.

DOE Order 451.1, National Environmental Policy Act Compliance Program; DOE Order 5482.1B, Environment Safety and Health Appraisal Program for Department of Energy Operations; and DOE Order 5480.23, Nuclear Safety Analysis Reports provide the basis for review of all planned and existing construction and operation to determine the potential for accidents and the assessment of the associated human health and environmental consequences, should an accident occur. The results of these reviews are used as the basis for determining the need for controls or other mitigative actions to eliminate or greatly reduce the potential for and consequences of an accident. These reviews are required before authorization of construction or start of operation. These reviews also involve the identification of hazards and an analysis of normal, abnormal, and accident conditions. This analysis includes consideration of natural and man-made external events, including fires, floods, tornadoes, earthquakes, other severe weather events, human errors, and explosions.

In accordance with DOE Order 151.1, Emergency Management System, emergency response planning and training are provided to mitigate the consequences of potential accidents. Additionally, should an accident occur, the incident would be reported in accordance with DOE Orders 232.1, Occurrence Reporting and Processing of Operations Information. The reports would also include appropriate corrective action(s) and followup.


4.14.2 Impacts of Proposed Action

Under the Proposed Action, the following activities would occur at Pantex Plant:

  • Assembly, disassembly, repair, retrofit, and evaluation of nuclear weapons in support of the national security policy.
  • Development, fabrication, and testing of chemical high explosive(s) (HE)high explosive(s) (HE) and HE components.
  • Nuclear material staging as defined in section 3.1. Normal operational impacts associated with Zone 4 staging, and associated material movement are discussed in section 4.12, Intrasite Transportation.
  • Construction and operation of new facilities. These are discussed in section 3.1.

This section describes the human health impacts from these activities.

Table 4.14.2.1-1.--Radiological Exposures to Workers from Normal Weapons Operations (.pdf)


4.14.2.1 Impacts of Continued Operations

The continuation of weapons-related operations at Pantex Plant would result in the continuation of radiological exposures to plant workers. Table 4.14.2.11 presents the expected radiological impact from future weapons operations based on historical exposures.

The combined involved worker dose from 10 years of operation at the 2,000 weapons activity level is estimated at 330 person-rem based on historical doses. Assuming that only 330 radiation workers (based on 1994 operations) are involved in weapon operations over a period of 10 years (i.e., these people receive the entire plant dose), they would receive an average of 0.1 rem per person per year. The maximum dose an individual involved worker is allowed to receive annually is administratively limited to 900 mrem during normal operations. These involved workers include support personnel (e.g., auditors, inspectors) that participate in weapon operations.

Using a normal operations dose-to-risk conversion factor of 4 x 10-4 excess cancer fatalities per person-rem, there would be an additional 0.13 excess cancer fatalities experienced by this group in their lifetime. The probability of fatal cancer from all causes in the general population is estimated at 20 percent (NAP 1990:174), which implies that, on average, 66 of 330 people would develop a fatal cancer from all causes in their lifetime. As the weapon activity level decreases, so would the number of workers. The total person-rem and excess cancer fatalities would also decrease.

Non-involved personnel are not allowed in the vicinity of weapon operations and do not receive doses from weapons operations. The average dose to an individual member of the public or a non-involved worker results primarily from the small amounts of tritium offgassing from Cell 1, the small amounts from the Burning Ground, and the very small amounts that may escape during removal of tritium reservoirs. The total amount of tritium emissions are at the limit of detection. As a result, it is not possible to calculate doses and consequences to the non-involved workers and the public with high confidence levels. To the extent practicable, the dose to the public has been estimated to be less than 1.20 x 10-4 person-rem per year, resulting in 6.00 x 10-8 excess cancer fatalities. Practically speaking, the maximum dose to an individual maximally exposed non-involved workernon-involved worker or member of the public would be effectively zero.

The pit repackaging process is expected to begin operation in late 1996 or early 1997. It is planned that up to 20,000 pits will eventually be repackaged into AT400A containers. This process will require the transfer of pits between Zone 4 and Zone 12. Impacts related to these transfers are described in section 4.12.

The pit repackaging will occur within existing facilities within Zone 12. Operations occurring as part of the pit repackaging process include:

1) Pit Leak Checkto verify the integrity of the pit encapsulation, pits will be leak checked prior to repackagement.

2) Pit Cleaningpits with surface contamination that may initiate corrosion of the pit clad during storage will be cleaned prior to repackagement.

3) Placement of pits within inner containment vessel, inner containment vessel welding, inert gas introduction into inner containment vesselpits will be placed within the inner containment vessel of the AT400A container. These vessels will be welded shut and filled with an inert gas mixture. The inner containment vessel will be leak checked to ensure the integrity of both the pit and the inner containment vessel.

4) Placement of inner containment vessel into outer containment vesselonce the integrity of the inner containment vessel is verified, the vessel will be placed in the AT400A outer containment vessel. Further description of the AT400A outer containment vessel is provided in volume II, appendix F.

All operations involving pits will be performed in a manner that minimizes radiological exposures to facility workers. However, the pit repackaging process will result in additional exposures at Pantex Plant. Because pit repackaging has not been done with this type container, there is no historical dosimetry information available. Therefore, conservative dose estimates have been made for this operation. For 2,000-pit repackage operations per year, it is estimated that an additional worker exposure of less than 30 person-rem will be incurred. Similarly, an additional worker exposure of less than 300 person-rem for the repackaging of 20,000 pits will be incurred. Using a normal operations dose-to-risk conversion factor of 4 x 10-4 excess cancer fatalities per rem, less than 0.12 excess cancer fatalities would be incurred in the workforce from this operation.

The dose estimates provided for the pit repackaging process are based on initial scoping studies performed prior to operation of the process. DOE expects that the actual worker doses will be less than the presented estimates. Additionally, as the pit repackaging effort proceeds, DOE will utilize the experience gained from initial operations to further reduce worker exposures.

Impacts of Potential Facility Accidents

For the purpose of this discussion an accident is defined as an unexpected or undesirable event that leads to a release of hazardous material within a facility or into the environment. Events that could result in an accidental release of hazardous material fall into three broad categories: external events, internal events, and natural phenomena events. External events (e.g., aircraft crashes and resulting explosions or fires) originate outside a facility. Internal events (e.g., equipment failures or human errors) originate within a facility. Natural phenomena events include weather-related occurrences (e.g., tornadoes and severe winds) and earthquakes. All of these events could lead to a release of hazardous material from a facility.

Identification of Risk Significant Accident Scenarios

Assessing the threat to public and worker health from potential accidents at Pantex Plant involved a screening process. The first step of this process was to identify a broad spectrum of potential accident scenarios that could occur during continued operations.

Facilities and operations at Pantex Plant have been analyzed to identify all hazards and potential accidents associated with the facilities and process systems, components, equipment, or structures and to establish design and operational means to mitigate these hazards to prevent potential accidents. The results of these analyses are contained inSafety Analysis Report (SAR) safety analysis reports and other safety basis documents including:

  • Basis for Interim Operations for the Pantex PlantAmarillo, Texas, Pantex Plant, June 1995 (Pantex 1995j).
  • Basis for Interim Operations for the Non-Nuclear FacilitiesAmarillo, Texas, Pantex Plant, September 1995 (Pantex 1995).
  • Chemical High Explosives Hazards Assessment for the Pantex Plant, Jacobs Engineering, October 1993 (Jacobs 1993a).
  • Natural Phenomena Hazards Assessment for the Pantex PlantAmarillo, Texas, Jacobs Engineering, October 1993 (Jacobs 1993).
  • Recalculation of Potential Deposition Levels and Dose Exposure Levels for the Pantex Radiological Hazards Assessment, Jacobs Engineering, October 1993 Jacobs 1993b).
  • Pantex Plant, Safety Information Document, prepared for the U.S. Department of Energy, Albuquerque Operations Office, Albuquerque, NM, September 1996 (Pantex 1996a).

For each facility and operation at Pantex Plant, DOE has developed or is in the process of developing a safety analysis report. In addition, other facility-specific safety analyses have been performed and documented (e.g., process hazards reviews, hazards analysis documents, and justifications for continued operations). These documents were also utilized for the identification of potential accidents at Pantex Plant.

DOE Order 5480.23, Nuclear Safety Analysis Report (SAR)Safety Analysis Reports, provides the most recent guidance to determine the safety basis for facilities at Pantex Plant. However, safety analyses have been conducted at Pantex Plant for more than a decade using a gradually evolving chain of guidance documentation. Therefore, the safety documents used as a basis for the identification of potential accidents at Pantex Plant in this EIS represent a continuum of safety assessments. Appendix A in the Safety Information Document provides a list of DOE orders, statutory and regulatory requirements, codes, and other applicable standards relevant to the design and safe operation of Pantex Plant (Pantex 1996a).

The next step of the screening process involved the identification of representative accidents that contribute to the risk to public and worker health from continued Pantex Plant operations. Ideally, a complete evaluation of Pantex Plant Site risks would include all potential accident scenarios. However, this type of an approach is impractical. Therefore, the purpose of this step in the screening process was to identify a subset of accident scenarios that contribute a large fraction of the total risk from Pantex Plant operations. This step of the screening process involved the grouping of potential accidents based on both the magnitude of the frequency of occurrence and the magnitude of the expected consequence. Once the accidents were grouped, the accidents corresponding to the highest risk in each group were chosen for further analysis. (Further information on the accident scenario identification is available in volume II, appendix D, Human Health Analysis.)

Table 4.14.2.1-2.--Summary of Consequences to the Public from Risk Significant Accidents at Pantex Plant: Configuration (.pdf)

Table 4.14.2.1-2 lists the scenarios that were identified as risk significant for Pantex Plant. This table includes both high-frequency low-consequence scenarios (such as those occurring during normal operations) and unlikely (low-frequency) scenarios that have potentially high consequences (i.e., scenarios initiated by natural phenomena or external hazards). Societal risk (listed in the column heading of that table) is the number of adverse events (in this case, excess cancer fatality risk) per year for a specified population. The frequency categories shown in Table 4.14.2.12 are explained below:

  • Anticipated events have a frequency greater than or equal to 10-2 per year. Most anticipated events would be expected to occur at least once within a human lifetime (conservatively assumed to be 100 years).
  • Unlikely events have a frequency between 10-2 per year and 10-4 per year. Unlikely events are not expected to occur within a human lifetime. The chances of an unlikely event occurring within a human lifetime range from approximately 50 percent to less than 1 percent. Most unlikely events would not be expected to occur over a time span equal to the 200-year history of the U.S.
  • Extremely unlikely events have a frequency between 10-4 per year and 10-6 per year. Extremely unlikely events are so rare that the chances of one occurring within a human lifetime range from less than 1 in 100 to less than 1 in 10,000. Extremely unlikely events would not be expected to occur over a timespan equal to the history of human civilization.
  • Not reasonably foreseeable events have a frequency below 10-6 per year. The chances of such an event occurring within a human lifetime (100 years) are fewer than 1 in 10,000 (10-6 x 100 = 1 in 10,000). Examples of not reasonably foreseeable events are catastrophic natural phenomena. One such example is the impact of a meteorite in the U.S. severe enough to cause thousands of fatalities.

For all scenarios, the frequency and consequence assessments are performed on a site-wide, rather than a facility-specific basis.

For the accidents identified as risk significant, detailed consequence assessments were performed. The consequence assessment focused on exposures to involved and non-involved workers and the public. Radiological consequences to the public were evaluated using site-specific meteorological data, local demographic data, and either the Melcor Accident Consequence Code System (MACCS) Melcor Accident Consequence Computer Code System (MACCS) or the Explosive Release Atmospheric Dispersion (ERAD) computer code system. MACCS was principally used to model health impacts from scenarios that did not involve explosions, while the ERAD computer code system was used primarily to model the health impacts from releases initiated by explosions (see volume II, appendix D for additional information on MACCS and ERAD). Human health impacts were evaluated in terms of cumulative radiological exposure from an accident and the societal risks (subsequent number of expected excess LCFs). This process is summarized in Figure 4.14.2.11.

Expected Change in Societal Risks from Potential Pantex Accidents

During preparation of the Draft EIS, Pantex Plant personnel discovered that particular assembly/disassembly cells had larger gaps between the edges of personnel and/or equipment doors and their frames than had been analyzed in prior studies. The cumulative gaps around the personnel and equipment doors of individual cells varied, but the worst case resulted in a total gap area greater than the 42 square inches that had been analyzed in previous Safety Analysis Reports. Since the gap area affects the amount of radioactive material that can be forced out of a cell by the air pressure of an explosive accident, plant personnel immediately reported the variance and initiated an Unreviewed Safety Question.

To resolve the issue, the plant immediately implemented measures to reduce the amount of high explosives and plutonium allowed in the cell and then modified the doors to close the total gap area of each cell to less than 42 square inches. Additional modifications have been designed to further close the gap area of each cell to less than 5 square inches. These modifications have been approved and funded for implementation in Fiscal Year 1997. The Final EIS includes health risk analysis of cell accidents that portray a bounding gap area (42 square inches) and the future gap area (5 square inches).

In the interim period until modifications are completed, Pantex Plant is operating the cells under a Justification for Continued Operation (JCO) (MH 1996d). This JCO establishes administrative controls to minimize the consequences of a potential accident until the end objective of reducing the door gap area to 5 square inches is reached.

Currently, nuclear explosive cells (gravel gerties) have a bounding overall leak area of 42 square inches. Pantex Plant will reduce these leak areas such that the total leak area will be less than 5 square inches. For the purpose of analysis, Scenario 1, Configuration 1 assumes a 42-square inch leak area for the gravel gerties. The societal and individual risks from this configuration are presented in Table 4.14.2.12 and in the text in the following section.

Scenario 1, Configuration 2 is representative of the plant configuration when a leak area of less than 5 square inches is achieved. Table 4.14.2.13 presents the changing risks for Scenario 1 and for the overall societal risk. Individual exposure and risks for both the 5-square inch and 42-square inch configuration are discussed in the following section.

The societal risk in the Pantex Plant ROI from potential plant accidents is also dependent on the storage configuration of the Zone 4 West magazines. Two configurations are analyzed that describe the changes in storage configuration expected in the future. The changes in storage configuration expected in the next 10 years involves the increase in pit storage and corresponding decrease in weapon storage within Zone 4 West. Configuration 1 involves the storage of 12,000 pits within Zone 4 West in 36 total magazines. The remaining 24 magazines are in use for weapons storage. The societal and individual risks from this configuration are presented both in Table 4.14.2.12 (Scenarios 3 and 8) and in the following section. This configuration presents the highest risk for Pantex Plant operations.

Configuration 2 is representative of the plant configuration as fewer weapons and more pits are stored within Zone 4 West. Configuration 2 includes 60 magazines for pit storage and no weapons storage within Zone 4 West. The overall societal risks from potential accidents decrease as the storage configuration evolves. Table 4.14.2.13 presents the changing risks for those scenarios affected (Scenarios 3 and 8) by the storage configuration evolution as well as the change in overall societal risks.

Discussion of Risk Significant Accident Scenarios

The description of Scenario 1 includes explicit calculations for deriving the value discussed. These calculations are included to provide an example of how the values in the rest of the scenarios were derived. Unless otherwise noted, accident frequencies are based on the 2,000 weapons operational level.

Scenario 1: Explosive Driven Plutonium Dispersal from an Internal Event. Nuclear weapons may be made with either conventional or insensitive HE, depending upon weapon design. Scenario 1 represents the accidental detonation of conventional HE in the presence of plutonium due to an internally initiated event. high explosive(s) (HE)HE is present with radioactive materials in facilities where nuclear explosives work occurs. Initiators for this scenario include accidental actuation of an electro-explosive device during disassembly and handling accidents. Insensitive HE is a negligible risk contributor because it is not susceptible to ignition under the conditions existing during assembly or disassembly operations. Insensitive HE is, thus, not a credible explosive source for this scenario.

Scenario 1 is comprised of three individual cases in which an accidental HE detonation is postulated to be initiated by an internal event. These cases differ in where the accidental detonation occurs; i.e., in a nuclear weapons assembly and disassembly cell, a bay, or a special purpose building. An HE detonation during assembly or disassembly would lead to the dispersal of radioactive material. Weapons are designed so that, in the event of an accidental detonation, there will be no significant nuclear reactions. Positive measures are engineered into nuclear explosives to preclude a nuclear yield from an accidental HE detonation.

Table 4.14.2.1-3.--Societal Risk Evolution (.pdf)

For operation on 2,000 weapons annually, the frequency of Scenario 1 is 1.1 x 10-5 per year. It is, thus, extremely unlikely (frequency of occurrence is less than 10-4 per year but greater or equal to 10-6 per year). The derivation of this frequency involves summing of probabilities of different initiating events in different facilities (see appendix D, section D.4.1). Explosive driven plutonium dispersal from an internal event can result from operations conducted in bays, cells, or special purpose facilities. The probability per operation that an operational error could cause an explosive driven plutonium release was estimated for each facility using data from available safety analyses (see references mentioned in section 4.14.2.1 as well as those cited in individual scenario descriptions). The frequency per year was then quantified by multiplying the probability per operation by the annual number of operations in each facility and summing the results.

Should this scenario occur, the public dose impact is estimated to be 1,200 person-rem for a cell leak area of 42 square inches and 660 person-rem for a cell leak area of 5 square inches. The consequence of Scenario 1 would be 5.9 x 10-1 excess fatal cancers in the population within 80 kilometers (50 miles) of Pantex Plant for a cell leak area of 42 square inches and 3.3 x 10-1 excess fatal cancers for a cell leak area of 5 square inches.

The derivation of this consequence involves calculating a weighted average of the consequence from the event occurring in bays, cells, and special purpose facilities. The consequences are calculated separately for the Scenario 1 accident occurring in a cell, bay, or special purpose facility. A weighted average is then obtained by multiplying the consequence related to each facility by the frequency of the event occurring in that facility and then summing the results. This result, which represents the overall risk, is divided by the frequency of Scenario 1 to obtain the frequency weighted consequence for the scenario. This process is illustrated in Figure 4.14.2.1-2.

Figure 4.14.2.1-2.--Consequence Calculation for Scenario 1.

The bounding public dose impact to an individual is represented by a hypothetical person is located at the site boundary closest to the radiological release. The wind is assumed to blow the radiological release directly towards this individual. The bounding dose impact to a non-involved worker is represented by a hypothetical person located 100 meters (328 feet) downwind of release point. The exposures to the MEOI and to the non-involved worker for each of the cases is presented in Table 4.14.2.1-4.

Table 4.14.2.1-4.--Representative Doses (REM CEDE) to Maximally Exposed Offsite Individuals and Non-Involved Workers for Individual Casesin Scenario 1 (.pdf)

The MEOI exposure is dominated by the case in which the accidental explosion occurs in a cell using a cell leak area of 42 square inches (i.e., for Configuration 1). The MEOI exposure is dominated by the case in which the accidental explosion occurs in either a bay or a special purpose facility using a cell leak area of 5 square inches (i.e., for Configuration 2). The doses for all accident scenarios are given as committed effective dose equivalents, which mean a 50-year committed dose, not an acute exposure.

The exposure to the maximally exposed non-involved worker is dominated by the case in which the accidental explosion occurs in a cell. The non-involved worker would be expected to receive an exposure of 2300 rem using a cell leak area of 42 square inches and exposure of 600 rem using a cell leak area of 5 square inches. This exposure to the non-involved worker is greater for the cell case because the plume of plutonium exits the cell at ground level and over a longer period of time through the very small gaps under the cell doors. Alternatively, the plume for the bay case or special purpose building case would exit very quickly through the roof. In addition, the cell case plume is less energetic, which would result in higher nearby concentrations. Public risk issues are discussed in detail later in this section as well as in Figure 4.14.1.11.

Note that the dose to the MEOI presented here is the bounding consequence for this accident scenario. As illustrated in Table 4.14.2.14, this scenario covers the consequences from three facilities, cell, bay, and special purpose buildings. Each facility has a slightly different consequence. Likewise, within each facility, operations on differing weapon systems occur. Each of these different weapon systems would have a different consequence at the site boundary. For example, in the Bay Safety Analysis Report (DOE 1996i), a dose range of 3 to 30 rem is estimated. This difference is dependent on the HE/Pu ratios from different weapon systems. However, the dose estimates in this document are point estimates that bound all weapons related operations at Pantex Plant.

The MEOI dose is a consequence measure, not a risk estimate. The reason for this is because the MEOI is an entirely hypothetical receptor. A reasonable estimate of the frequency that such a receptor is exposed to the scenario requires multiplying the scenario frequency by the probability that a receptor is actually located at the nearest point on the site boundary when the accident occurs, and further multiplying by the probability that the wind is blowing toward the receptor. Although available data are too limited to permit quantifying the probability that a receptor is actually located at the nearest point on the site boundary, the probability that the wind is blowing towards that point is approximately 0.05 for Scenario 1.

No prompt fatalities would be expected among members of the public. However, workers within the cell at the time of an accidental explosion would not be expected to survive. With 267,107 people in the Region of Influence (ROI)ROI, the average risk to a person in the ROI is on the order of 2.4 x 10-11 excess fatal cancers per year with a cell leak area of 42 square inches and 1.3 x 10-11 excess fatal cancers per year with a cell leak area of 5 square inches. The increased annual risk to a person is calculated by multiplying the frequency of the accident by the public consequences which have been averaged over the population in the ROI (i.e., 1.1 x 10-5 per year x 5.9 x 10-1 excess fatal cancers spread over 267,107 people). Cancer statistics indicate that the fatal cancer risk from all causes to a person in the vicinity of Pantex Plant is 1.7 x 10-3 fatal cancers per year.

The societal risk (annual expected number of excess cancer fatalities) is 6.3 x 10-6 excess fatal cancers per year (see Table 4.14.2.13) for a cell leak area of 42 square inches and 3.5 x 10-6 excess fatal cancers per year for a cell leak area of 5 square inches. This number is calculated by multiplying the excess fatal cancers resulting from the accident by the frequency of the accident (i.e., 5.9 x 10-1 excess fatal cancers x 1.1 x 10-5 per year).

Scenario 2: Accidental high explosive(s) (HE)High Explosives Detonation from an Internal Event. This scenario represents the accidental detonation of HE, but without radioactive material present, due to an internally initiated event. This includes accidents associated with HE development, manufacturing, testing, evaluation, and treatment. Initiators that contribute to this scenario include handling accidents and mechanical failures resulting in HE detonation during HE machining (Pantex 1993).

The likelihood of this event is anticipated (frequency of occurrence greater than or equal to 10-2 per year). A fatal accident of this type has occurred once at Pantex Plant (in 1977) in over 40 years of operation. The specific circumstances that led to the prior occurrence no longer exist. The manually operated HE machining process was replaced by a robotic process.

This scenario poses a risk to worker safety. There is a possibility of a fatal injury resulting directly from the HE explosion, not from radionuclide exposure. Members of the public and non-involved workers are not at risk from this scenario.

Scenario 2 has a higher frequency than Scenario 1 because HE development, manufacturing, testing, evaluation, and treatment routinely expose bare HE to external stresses (e.g., stresses associated with HE machining) greater than the stresses associated with routine assembly/disassembly operations. If these stresses exceed allowable limits, an inadvertent HE detonation is possible. Although accidental HE detonations of the type included in Scenario 2 have occurred at Pantex Plant, none of the accidents included in Scenario 1 have been experienced.

Scenario 3: Explosive Driven Plutonium Dispersal from an External Event or Natural Phenomena. This scenario represents the accidental detonation ofhigh explosive(s) (HE) HE, in the presence of plutonium and tritium, due to an aircraft crash. HE is present with radioactive materials within nuclear explosives and in facilities where nuclear explosives work occurs. Initiators that contribute to this scenario include an aircraft impact initiated HE detonation in a Zone 12Zone 12 facility containing nuclear material and an aircraft impact initiated HE detonation in a Zone 4Zone 4 nuclear weapon storage magazine (DOE 1992f).

This scenario is dominated by an aircraft impact into a Zone 4 weapons magazine resulting in the HE detonation of numerous weapons with a small contribution from aircraft impacts into nuclear explosive bays. The overall likelihood of this scenario occurring is not reasonably foreseeable (frequency of occurrence is less than 10-6 per year). The public dose impact from this event is estimated to be 16,000 person-rem. No prompt fatalities would be expected in members of the public. The MEOI would be expected to receive an exposure of 60 rem. This corresponds to an incremental increase in lifetime fatal cancer probability of 3 x 10-2. The 100-meter (328-foot) non-involved worker is not expected to survive the aircraft crash and explosion. If the individual did survive, the maximum expected dose would be 40 rem corresponding to an increase in lifetime fatal cancer probability of 1.6 x 10-2. The non-involved worker is closer to the postulated release than the MEOI, yet receives a lower dose. This is due to the initial buoyancy of the released material as a result of the explosively driven dispersal event.

Considering the likelihood and consequence of this scenario, on the average, a member of the public will have an increased risk of developing a fatal cancer from this potential accident of 2.7 x 10-11 excess fatal cancers per year. The annual fatal cancer risk to a person in the vicinity of Pantex Plant from all causes is 1.7 x 10-3 fatal cancers per year.

Scenario 4: Accidental High Explosives Detonation from an External Event or Natural Phenomena. This scenario represents the accidental detonation of HE, with no radioactive material present, due to a seismic event or an aircraft crash. The scenario could occur in staging facilities and facilities involved with HE development, production, and disposal. The main initiator of this scenario is the seismic collapse of an HE development or manufacturing facility (Pantex 1993). These facilities tend to have lower structural strength than nuclear facilities.

The overall likelihood of this scenario occurring is unlikely (frequency of occurrence is less than 10-2 per year but greater than or equal to 10-4 per year). The blast resulting from the explosion could fatally injure a worker in the vicinity. Members of the public and non-involved workers are not at risk from this scenario.

Scenario 5: Tritium Reservoir Failure from an Internal Event. This scenario represents the release of tritium due to a reservoir failure during normal operations. Initiators for this scenario include an inadvertent squib valve actuation during weapon operations.

This type of event has occurred at Pantex Plant, and the frequency of this event is strongly dependent on the number of weapon operations being performed. For the 2,000 weapons activity level, this scenario is anticipated (frequency greater than or equal to 10-2 per year). For the 500 weapons activity level, this event is unlikely (frequency of occurrence is less than 10-2 per year but greater than or equal to 10-4 per year) (Pantex 1996a, DOE 1995g). This scenario is dominated by handling accidents during weapon operations. The public dose impact from this event is estimated at 8.0 x 10-2 person-rem. The MEOI would be expected to receive an exposure of 1.1 x 10-2 rem. This corresponds to an increase in lifetime fatal cancer probability of 5.5 x 10-6.

Based upon the tritium exposure in 1244 Cell 1, cited in section 4.14.1.1, a maximally exposed workermaximum worker exposure of between 1 and 2 rem is expected. This corresponds to an increase in fatal cancer probability of 8 x 10-4 or less, if the accident occurs. The non-involved worker (i.e., 100 meters [328 feet] downwind) would be expected to receive an exposure of 3 x 10-1 rem. This corresponds to an increase in lifetime fatal cancer probability of 1.1 x 10-4 (see appendix D, Table D.4.2.22).

Considering the likelihood and consequence of this scenario, a member of the public would have, on the average, an increase in the risk of developing a fatal cancer from this potential accident of 3.6 x 10-12 excess fatal cancers per year. The fatal cancer risk to a person in the vicinity of Pantex Plant from all causes is 1.7 x 10-3 fatal cancers per year.

Scenario 6: PIT Breach from an Internal Event. This scenario represents a pit breach, with resultant plutonium release, during normal operations. Initiators that contribute to this scenario include a pit drop due to a handling accident and a pit breach due to a forklift accident (Pantex 1996a, DOE 1994w).

This scenario is dominated by handling accidents in bays and special purpose facilities. The overall likelihood of this scenario occurring is unlikely (frequency of occurrence is less than 10-2 per year but greater than or equal to 10-4 per year). The public dose impact from this event is estimated to be 3.7 x 10-4 person-rem. The MEOI would be expected to receive an exposure of 1.0 x 10-4 rem. This corresponds to an increase in lifetime fatal cancer probability of 5.0 x 10-8.

An individual worker would be expected to receive no more than a 7 rem exposure from Scenario 6 (DOE 1992f:7-40). This corresponds to an upper bound increase in fatal cancer probability of 2.8 x 10-3, given that the release occurs. The non-involved worker would be expected to receive an exposure of 4 x 10-3 rem. This corresponds to an increase in lifetime fatal cancer probability of 1.6 x 10-6.

Considering the likelihood and consequence of this scenario, a member of the public would have, on the average, an increase in the risk of developing a fatal cancer from this potential accident of 5.7 x 10-15 excess fatal cancers per year. The fatal cancer risk to a person in the vicinity of Pantex Plant from all causes is 1.7 x 10-3 fatal cancers per year.

Scenario 7: Multiple Tritium Reservoir Failure from an External Event or Natural Phenomena. This scenario represents the release of tritium from reservoir failures caused by a fire in the tritium storage vault. The fire could be initiated by a seismic event or aircraft crash.

The dominant event in this scenario is a seismic event initiated fire in the warehouse surrounding the tritium storage vault. For a release to occur, the protective vault fire door would have to be open and the fire protection system disabled by the seismic initiator. The overall likelihood of this scenario occurring is not reasonably foreseeable (frequency of occurrence is less than 10-6 per year) (Pantex 1994b, Pantex 1995i). The public dose impact from this event is estimated to be 110 person-rem. The MEOI would be expected to receive an exposure of 7.4 x 10-1 rem. This corresponds to an increase in fatal cancer probability of 3.7 x 10-4.

A worker inside the vault when the fire started would normally evacuate the area. Should a worker be trapped inside the vault, the expected consequence is a fatality due to heat and smoke inhalation. The non-involved worker would be expected to receive an exposure of 50 rem. This corresponds to an increase in lifetime fatal cancer probability of 2.0 x 10-2.

Considering the likelihood and consequence of this scenario, a member of the public would, on the average, have an increase in the risk of developing a fatal cancer from this potential accident of 8 x 10-14 excess fatal cancers per year. The fatal cancer risk to a person in the vicinity of Pantex Plant from all causes is 1.7 x 10-3 fatal cancers per year.

Scenario 8: Fire Driven Dispersal Involving Stored Pits from an External Event or Natural Phenomena. This scenario represents a pit breach, resulting in a plutonium release, initiated by a seismic event or aircraft accident. The main initiator for this scenario is an aircraft impact initiated fire in a Zone 4 pit storage magazinemagazine (DOE 1994w; DOE 1992f).

This scenario is dominated by a heavy aircraft impact into a Zone 4 pit storage magazine resulting in a fire driven dispersal from numerous pit containers. The overall likelihood of this scenario occurring is extremely unlikely (frequency of occurrence is less than 10-4 per year but greater or equal to 10-6 per year) with 20,000 pits in Zone 4 storage. It is not reasonably foreseeable with 12,000 pits in Zone 4 West. The public dose impact from this event is estimated to be 1,100 person-rem. No prompt fatalities would be expected in members of the public. The MEOI would be expected to receive an exposure of 34 rem. This corresponds to an incremental increase in lifetime fatal cancer probability of 1.7 x 10-2.

Workers in the vicinity of the crash and explosion would not be expected to survive. The non-involved worker would be expected to receive an exposure of 3,000 rem. This corresponds to an increase in lifetime fatal cancer probability of 1.0. This is a 50-year committed dose equivalent, which means that the radiological exposure is not acute, but occurs over a 50-year time period. Consequently, no actute radiological fatalities are expected (LLNL 1995).

Considering the likelihood and consequence of this scenario, a member of the public would, on the average, have an increase in the risk of developing a fatal cancer from this potential accident of 2 x 10-12 excess fatal cancers per year (with 20,000 pits in Zone 4 West). The fatal cancer risk, from all causes, to a person in the vicinity of Pantex Plant is 1.7 x 10-3 fatal cancers per year.

Scenario 9: Plutonium Dispersal from an External Event or Natural Phenomena. This scenario represents a tritium or plutonium release, without an explosion, caused by a seismic event or aircraft crash. Initiators include an aircraft impact initiated fire in a Zone 12 nuclear explosive facility and a seismic collapse of a special purpose facility (Pantex 1993a).

This scenario is dominated by seismic events resulting in structural failure of special purpose buildings containing nuclear explosives. Many stockpile support activities (e.g., testing and maintenance) are performed in older facilities without the structural strength of the storage magazines. Thus, these facilities are more vulnerable to external events and natural phenomena. The overall likelihood of this scenario occurring is unlikely (frequency of occurrence is less than 10-2 per year but greater than or equal to 10-4 per year). The public dose impact from this event is estimated to be 0.40 person-rem. The MEOI would be expected to receive an exposure of 2.0 rem. This corresponds to an increase in lifetime fatal cancer probability of 1.0 x 10-3.

A worker in the vicinity of the fire or facility collapse would not be expected to survive. The non-involved worker would be expected to receive an exposure of 3.7 rem. This corresponds to an increase in lifetime fatal cancer probability of 1.5 x 10-3.

Considering the likelihood and consequence of this scenario, a member of the public would, on the average, have an increase in the risk of developing a fatal cancer from this potential accident of 2.5 x 10-13 excess fatal cancers per year. The fatal cancer risk to a person in the vicinity of Pantex Plant from all causes is 1.7 x 10-3 fatal cancers per year.

Scenarios 10 and 11: Chlorine Releases. All potential accidental chemical releases were evaluated using the risk screening methodology. Chlorine was the risk dominant chemical accident. Chlorine is the only chemical with the potential for significant adverse offsite consequences.

Table 4.14.2.13 identifies chlorine as the hazardous chemical dominating the risk from nonradiological releases (predicated upon the screening methodology described in appendix D). Since chlorine is not carcinogenic, the consequences of exposure to chlorine (primarily acute effects) differ from the consequences of exposure to radionuclides (potential latent cancers). This difference precludes a direct comparison between the risk and consequences associated with hazardous chemical releases and radionuclide releases.

A useful measure of potential human health effects resulting from exposure to non-carcinogenic chemicals is the hazard index. In its most general form, a hazard index is a ratio of the actual exposure of a human receptor to an established exposure limit. If this ratio is appreciably less than unity, no adverse human health effects are expected. If the hazard index is close to unity, some adverse human health effects may occur; and if the hazard index is substantially greater than unity, severe health effects can result.

ERPG DEFINITIONS

ERPG1 is the maximum airborne concentration below which nearly all individuals could be exposed for up to 1 hour without experiencing other than mild transient adverse health effects or perceiving a clearly defined objectionable odor.

ERPG2 is the maximum airborne concentration below which nearly all individuals could be exposed for up to 1 hour without experiencing or developing irreversible or other serious health effects or symptoms that could impair their abilities to take protective action.

ERPG3 is the maximum airborne concentration below which nearly all individuals could be exposed for up to 1 hour without experiencing or developing life-threatening health effects.

Numerous exposure limits are available to form a hazard index. Since exposure to an accidental chlorine release is an unlikely, short-duration event, chronic exposure limits are inapplicable. Instead, Emergency Response Planning Guidelines (ERPG) values will serve to develop hazard indices for chlorine exposure.

Scenarios 10 and 11 both involve chlorine releases. The impact of these scenarios represents a residual risk at Pantex Plant and is independent of the alternatives. The rooms in which chlorine gas is used are equipped with a chlorine sensor alarm system that consists of an alarm siren and flashing light located outside the building. The sensor system is set to activate this alarm at a chlorine concentration of 1.0 part per million in the air. The rooms are also ventilated with a floor-level exhaust fan and contain an elevated fresh air inlet.

Scenario 10 is a chlorine release due to failure of system piping and valves or cylinder caused by a seismic event. Scenario 11 is a similar accident initiated by an internal event, such as operator error. Chlorine is used in two facilities, 1529 and 1347. A release of chlorine to the environment due to an earthquake is an unlikely event.

Should an earthquake occur with sufficient magnitude to damage one of the facilities that uses chlorine, there is a reasonable chance that the second facility would also be damaged. In each of the two facilities, two chlorine cylinders are in use. Thus, an earthquake that damages both facilities could release the contents from the four chlorine cylinders in use. Other chlorine cylinders in the facilities are not ordinarily expected to contribute to a release initiated by an earthquake. However, in the unlikely event that a chlorine cylinder is stored without its valve cap in place or is substandard structurally when delivered, it is conservatively postulated that Scenario 10 could involve a release from up to six chlorine cylinders. The magnitude of this chlorine release could be as high as 408 kilograms (900 pounds) (Pantex 1996a). For Scenario 11, the expected release to the environment is no more than the contents of one chlorine cylinder, 68 kilograms (150 pounds), and the frequency classification for this release is also unlikely.

Prior assessments disclose that, if Scenario 11 were to occur, an ERPG1 concentration of 1 part per million is exceeded out to approximately 10.5 kilometers (6.5 miles), an ERPG2 concentration of 3 parts per million is exceeded out to 6.5 kilometers (4 miles), and an ERPG3 concentration of 20 parts per million is exceeded out to almost 3.0 kilometers (2 miles) (Pantex 1996a). Using Pantex-specific demographic and meteorological data, it is estimated that less than 1 percent of the downwind population would be exposed to a concentration exceeding ERPG1 levels, and that even fewer members of the public would be exposed to higher concentrations. Moreover, since ERPG1 and higher concentrations are perceptible by humans, persons experiencing ERPG1 or higher concentrations can move away from the chlorine plume, thus minimizing their exposure duration.

Releasing 408 kilograms (900 pounds) of chlorine to the environment would result in approximately 10 percent of the public downwind from the release being exposed to ERPG1 or higher concentrations, but less than 1 percent would be exposed to concentrations exceeding ERPG2. Because of the likelihood that people exposed to concentrations in excess of ERPG1 would evacuate the area of the chlorine plume, no long-term adverse public health impacts are anticipated for Scenario 10.

No adverse health impacts are expected from Scenario 11 for persons capable of evacuating the area of the chlorine plume.

Workers in the vicinity of a chlorine release (either Scenario 10 or 11) could be exposed to chlorine concentrations in excess of EPRG3 and threshold levels. No long-term adverse health effects are expected for workers who promptly evacuate the area. For any persons incapable of evacuating the area of the chlorine plume, no serious or irreversible health impacts are expected from EPRG1 or EPRG2 exposures since the exposure duration is less than 1 hour. Persons incapable of evacuating an area with EPRG3 concentrations may experience adverse health impacts depending upon the actual chlorine concentrations encountered and the exposure duration. However, chronic lung disease, electrocardiographic changes, and death have occurred in humans exposed to high concentrations of chlorine as a consequence of industrial accidents (Calabrese 1991).bk-1maximally exposed offsite individual (MEOI) bk-1maximally exposed non-involved worker

Ultimate Fate of Radionuclides from Accidental Releases

Potential consequences to the Ogallala aquifer from an accidental plutonium release were investigated in conjunction with a Safety Analysis Report (SAR)Safety Analysis Report and an Environmental Assessment by Los Alamos National Laboratory (LANL) (LANL 1992:1, 2, 10). The hypothetical accident leading to dispersal of plutonium to the environment around Pantex Plant was assumed to be a high-temperature fire caused by a jet plane impact into a Zone 4 storage magazinemagazine containing nuclear weapons components, and subsequent ignition of jet fuel.

LANL envisioned that the hypothetical jet fuel fire could disperse fine particulate plutonium downwind of Pantex Plant for a maximum distance of 80 kilometers (50 miles). Prompt decontamination efforts could reduce radiation levels to 0.2 microcuries per square meter, but surface runoff and wind transport could concentrate contamination at playa lakes, where surface soil radiation levels could be as high as 2.0 microcuries per square meter. Surface water infiltrating through this contaminated soil could carry plutonium and decay products down toward the Ogallala aquifer. The model assumed an average recharge rate of 3 centimeters (1 inch) per year (10 times the High Plains average), and that recharge water would reach the Ogallala aquifer at a depth of 20 to 100 meters (50 to 400 feet).

With these conservative assumptions in place, LANL performed two analyses. The first, an ultra-conservative non-dispersive piston-flow model, assumed that a contaminated layer of 3 centimeters (1 inch) of water moves downward through a 1-dimensional column in the unsaturated zone to the water table completely intact (i.e., without interacting with any other water or soils). The results of the non-dispersive piston-flow model indicated that plutonium levels would exceed calculated Environmental Protection Agency drinking water limits (1.3 picocuries per liter) in a 20-meter (50-foot) deep aquifer after approximately 76,000 years at an approximate maximum level of 7,700 picocuries per liter.

The second, more realistic analysis accounted for the processes of dispersion (i.e., mixing processes) that effectively change the composition of water as it would move downward through the soil column. The results showed that when the processes of dispersion were taken into account, peak plutonium levels in the 20-meter (50-foot) aquifer would never exceed the most restrictive drinking water dose limits. Additional factors were also qualitatively analyzed. These included colloidal plutonium transport, preferential flow, the effects of perched aquifers, opportunities for "short-circuit" flow through abandoned wells or other conduits, and fate of daughter products.

Of these factors, the one that would appear to produce the greatest effect would be short-circuit recharge paths to the Ogallala aquifer via unintentional flow through improperly constructed or abandoned water wells or intentional flow to the Ogallala aquifer as part of an artificial recharge project. The risk of short-circuiting along improperly constructed or abandoned wells could be mitigated by identification and sealing of these wells. In the event of a plutonium dispersal accident, active groundwater recharge projects should be monitored and, if necessary, shut down (LANL 1992:1, 11-15, 17-18, 31-32).

The final conclusion of these analyses is that the hypothetical plutonium dispersal accident does not pose a significant threat to the Ogallala aquifer. The assumptions of the analyses are extremely conservative because the scenarios were based on a depth to the water table of 20 meters (50 feet) whereas, at Pantex Plant, the typical depth to the top of perched groundwater is approximately 82 meters (270 feet), and the depth to the main Ogallala aquifer ranges from 104 to 140 meters (340 to 460 feet).

For water table depths of 60 and 100 meters (200 and 400 feet), LANL calculated plutonium travel times of 305,000 and 610,000 years, respectively. Interactions with both surficial materials and the unsaturated portion of the Ogallala Formation would be expected to retard the movement of plutonium relative to the infiltrating water (i.e., plutonium would move at a rate slower than the infiltrating water). During the transport time, radioactive decay would be expected to further reduce plutonium concentrations (LANL 1992:10,12). Where the perched aquifer is present, the downward movement of plutonium would be further reduced, because the low-permeability fine-grained zone would impede downward flow and potential contamination would be more likely to move horizontally and follow the course of buried channel sands and gravels, as discussed in section 4.6.1.2.

Conservatisms

The sequence of analyses performed to generate the radiological impact estimates from normal operation and facility accidents include: (1) selection of normal operational modes and accident sequences, (2) estimation of source terms, (3) estimation of environmental transport and uptake of radionuclides, (4) calculation of radiation doses to exposed individuals, and (5) estimation of health effects. There are uncertainties associated with each of these steps. Uncertainties exist in the way the physical systems being analyzed are represented by computational models and in the data required to exercise the models (due to measurement errors, sampling errors, or natural variability).

In principle, one can estimate the uncertainty associated with each source and predict the remaining uncertainty in the results of each set of calculations. Thus, one can propagate the uncertainties from one set of calculations to the next and estimate the uncertainties in the final results. However, conducting such a full-scale quantitative uncertainty analysis is neither practical nor a standard practice for a study of this type. Instead, the analysis is designed to ensurethrough judicious selection of release scenarios, models, and parametersthat the results bound the potential risks. This is accomplished by making conservative assumptions in the calculations at each step.

The models, parameters, and release scenarios used in calculations are selected in such a way that most intermediate results and consequently, the final estimates of impacts are greater than what would be expected. As a result, even though the range of uncertainty in a quantity might be large, the value calculated for the quantity is close to one of the extremes in the range of possible values, so that the chance of the actual quantity being greater than the calculated value is low (or the chance of the quantity being less that the calculated value if the criteria are such that the quantity has to be maximized). This has been the goal of the radiological assessment for normal operation and facility accidents in this study (i.e., to produce results that are conservative).


4.14.2.2 Impacts of New Facility Construction and Upgrades

Radiological exposure related to activities associated with new projects and facilities, as described in section 3.1.1, will be small. Additional radiological exposures related to the new projects and facilities are bounded by the Table 4.14.2.11 estimates.

The construction of three planned facilitiesthe Gas Analysis Laboratory (GAL)Gas Analysis Laboratory, the Materials Compatibility Assurance Facility (MCAF), and the Nondestructive Evaluation Facility would reduce risks from operations in current facilities. These facilities would have a reduced risk because they would replace existing facilities used forhigh explosive(s) (HE) HE that are susceptible to seismic events.

The Pit Reuse Facility contribution to risk is expected to be small. As discussed in appendix H, it will introduce a process that breaches the pit tube as part of normal operations, which is not currently undertaken at Pantex Plant. Due to the limited number and nature of pit reuse operations planned, preliminary assessments indicate that incremental risk impacts from the Pit Reuse Facility would be barely perceptible. Further safety assessment would be conducted prior to the pit reuse facility becoming operational.

The human health impacts from the Hazardous Waste Treatment and Processing Facility (HWTPF)and the Metrology and Health Physics Calibration and Acceptance Facility are not expected to be significant.

4.14.2.3 Impacts of Environmental Restoration (ER) and Waste Management Activities

The scope and mission of the Environmental Restoration (ER) program is to assess all inactive solid waste management units, determine the nature and extent of contamination, and perform remediation to eliminate any substantial present or future threat to human health and the environment (Pantex 1995a:15-1 to 15-11). The program is conducted in compliance with all regulatory requirements. All Resource Conservation and Recovery Act Facility Investigation workplans have been approved, and field investigations have been initiated at all sites. Adequate data have been collected on many of the solid waste management units to recommend either no further action or interim corrective action.

The scope and mission of the ER program would not change under any of the alternatives to the Proposed Action. As currently active waste management sites become inactive, they will undergo environmental remediation as required by the Resource Conservation and Recovery Act permit (issued jointly by the Environmental Protection Agency and Texas Natural Resource Conservation Commission (TNRCC) authorizing Pantex Plant to store and process hazardous wastes. Since the purpose of the ER program is to eliminate any substantial present or future threat to human health and the environment, its net impact on human health is to reduce risk.


4.14.3 Impacts from No Action Alternative

Under the No Action Alternative, weapons operations would continue at Pantex Plant to meet the stockpile management requirements. Dismantlement activities would, however, cease when the 12,000 pit storage limit is reached.

The total number of weapons operations under both the Proposed Action and the No Action Alternative are assumed to be similar. Consequently, the frequencies of potential accident scenarios caused by internally initiated events are the same for the Proposed Action and No Action Alternatives. In addition, the impacts from normal operations would be similar.

The main difference between the Proposed Action and No Action Alternatives in terms of potential human health impacts is the number of pits stored in Zone 4Zone 4 and the effect of this change on the likelihood of an aircraft impact into a storage magazinemagazine. The likelihood of an aircraft impact into a pit storage magazine depends on the number of storage magazines in use. The storage of the 12,000 pits associated with the No Action Alternative would require the use of fewer storage magazines than would be required for the 20,000 pit storage level associated with the Proposed Action. The actual number of storage magazines required for 12,000 pits would be dependent on the storage configuration used by the plant. The use of fewer magazines for pit storage reduces the likelihood that an aircraft impact would breach a storage magazine that had pits inside.

An important difference in the impacts of the No Action Alternative is that the following facilities will not be replaced: the Gas Analysis Laboratory (GAL)Gas Analysis Laboratory, the Materials Compatibility Assurance Facility (MCAF)Materials Compatibility Assurance Facility, and theNondestructive Evaluation Facility Nondestructive Evaluation Facility. Without replacing these facilities with upgraded facilities, the existing facilities would remain more susceptible to seismic events.


4.14.4 Impacts of Pit Storage Relocation Alternative


4.14.4.1 Impacts of Relocating 20,000 Pits

Relocating 20,000 pits from Pantex Plant would eliminate the risk posed by aircraft crash into pit storage magazines at the plant. Impacts relating to offsite pit shipments are discussed in section 4.12, Intrasite Transportation, and section 4.16, Intersite Transportation of Nuclear and Hazardous Materials.

With the storage of no pits in Zone 4, the societal risk from risk significant accidents is dependent on the level of weapons storage within the 24 SAC magazines: the societal risk from risk dominant accidents is 1.5 x 10-5 excess fatal cancers per year. With no weapon storage within Zone 4, the plant risk is dominated by Zone 12: the societal risk from risk dominant accidents is 7.8 x 10-6 excess fatal cancers per year. Both societal risk estimates presuppose a 42-square-inch release area for cell explosions.


4.14.4.2 Impacts of Relocating 8,000 Pits

The significance of relocating 8,000 pits in terms of impacts from potential accidents is similar to the No Action Alternative described above.

With the storage of 12,000 pits, the societal risk is dependent on the level of weapons storage within Zone 4. With the storage of weapons within 24 SAC magazines, the societal risk from risk dominant accidents is 1.5 x 10-5 excess fatal cancers per year. With no weapon storage within Zone 4, the plant risk is dominated by Zone 12, the societal risk from risk dominant accidents is 8.1 x 10-6 excess fatal cancers per year. Societal risk estimates include 42 sq in release areas for cells.


4.14.4.3 Summary of Human Health Impacts

Table 4.14.4.31 presents a summary of Pantex Plant-related human health impacts from normal operations. Table 4.14.4.32 summarizes the impacts of radiological accidents at Pantex Plant.


4.14.5 Cumulative Impacts

The cumulative impacts presented here include impacts of the continued operations at Pantex Plant combined with impacts associated with activities described in the WM PEIS, SSM PEIS, and S&D PEIS. Since the Pantex Plant EIS Proposed Action and the SSM PEIS No Action Alternative represent a continuum of operations, the impacts associated with any new mission or facility that could be implemented at Pantex Plant are discussed in the context of that continuum. The impacts from the WM PEIS program are combined with those of the Pantex Plant EIS Proposed Action. The impacts from the S&D PEIS are generally combined with those of the SSM PEIS No Action Alternative. A detailed discussion of this methodology is presented in section 4.2.


4.14.5.1 Impacts of Alternatives in the Waste Management Programmatic Environmental Impact Statement

Pantex Plant is a potential site for location of the waste management facilities as described in the WM PEIS. If these facilities are located at Pantex Plant, they could result in additional impacts to workers and the public surrounding the plant. However, the WM PEIS has estimated human health impacts from waste management activities to be low; potential fatalities to the offsite population and to workers are essentially zero for treatment and disposal of low-level waste (LLW)low-level waste and low-level mixed waste (LLMW)low-level mixed waste under every alternative (DOE 1996).

The chemical environment for the Maximally Exposed Individual (due to an atmospheric release) is expected to result in chemical-related fatal cancer incidences ranging from 3 x 10-14 to 2.9 x 10-13. This is essentially zero risk of fatal cancers from exposure to chemicals.


4.14.5.2 Impacts of Alternatives in the Stockpile Stewardship and Management Programmatic Environmental Impact Statement

The SSM PEIS includes three alternatives that apply to Pantex Plant: No Action, Downsize Existing Capability, and Relocate Capability. Under the No Action Alternative, no downsizing or modification of facilities would occur. Due to the reduced workload expected in the future, human health impacts from operations are expected to be less than current impacts. The average radiological dose to workers would not be expected to change. The total worker dose, however, would change due to the reduced number of workers associated with a reduction in workload. Potential impacts from accidents, which are essentially independent of the level of operation, would not be expected to change.

Under the downsizing alternative, the average worker dose at Pantex Plant would be approximately 10 mrem per year. This would result in a total worker dose of 3.0 person-rem year, statistically equating to approximately 1 fatal cancer every 833 years. The incremental dose to the population within 80 kilometers (50 miles) would be 4.0 x 10-4 person-rem per year. The probability of a member of the public dying from cancer would be 2.0 x 10-7 year. Potential impacts from accidents were determined using computer modeling. For the composite accident, less than one fatal cancer would be expected for the population within 80 kilometers (50 miles).


4.14.5.3 Impacts of Alternatives in the Storage and Disposition of Weapons-Usable Fissile Materials Programmatic Environmental Impact Statement

The S&D PEIS is considering Pantex Plant for long-term storage of inventories of nonsurplus weapons-usable plutonium and highly enriched uranium (HEU), storage of inventories of surplus weapons-usable plutonium and HEU pending disposition, and disposition of surplus weapons-usable plutonium. For storage, the strategy for long-term storage of weapons-usable plutonium and HEU, as well as the storage site(s), would be decided. The storage alternatives include upgrading the existing plutonium storage facilities, consolidation of plutonium from other sites, and collocation of plutonium and HEU storage. The collocation alternative is used for analysis purposes in this EIS as the bounding storage alternative.

Under the S&D PEIS Collocation Alternative, construction of new storage facilities would be required in order to store plutonium and HEU at Pantex Plant. The annual dose to the public from the collocated facility would be 5.3 x 10-5 person-rem. This would cause an estimated 1.3 x 10-6 fatal cancers during 50 years of operation. The alternative of storing surplus pits from RFETS at Pantex Plant in the near-term could cause less than 10-2 fatal cancers for affected workers due to repackaging operations. There would be no effect to the public.

The final S&D PEIS will include an alternative that is a refinement of these storage alternatives. As discussed in sections 1.4 and 1.7.3 of this volume, the final S&D PEIS will include an alternative under which pits from Rocky Flats Environmental Technology Site (RFETS) could be transferred to Pantex Plant for storage in Zone 4 as early as 1997. The impacts of this alternative are fully accounted for in this EIS because the pits from RFETS could not cause the total number of pits stored in Zone 4 to exceed the storage limit of 20,000 pits analyzed under the Proposed Action. Furthermore, RFETS pits that could come to Pantex Plant would have the same characteristics, as analyzed in the S&D PEIS, as pits currently or previously stored at Pantex Plant.

For the disposition alternatives in the S&D PEIS, the emphasis at this stage in the NEPA decision process is on the strategy and technology mix rather than the actual site. The evolutionary Light Water Reactor is used for analysis purposes in this EIS as the bounding disposition alternative. Implementation of this disposition alternative would require the construction and operation of a pit disassembly and conversion facility, plutonium conversion facility, mixed oxide (MOX) fuel fabrication facility, and one or more light water reactors. The bounding alternative also assumes that all of the facilities previously mentioned would be collocated at the same site (potentially Pantex Plant).

During normal reactor operation, there would be both radiological and hazardous chemical releases to the environment and also direct in-plant exposures. All doses would be within radiological limits and well bePITvels of natural background radiation (DOE 1996a:4.0).


4.14.6 Potential Mitigation Measures

DOE will continue to strive to reduce radiological exposures to plant workers. Radiological exposures incurred from future weapons operations will be controlled and minimized by Pantex Plant procedures, administrative controls, and an active ALARA program that promotes work practices that minimize worker exposures. The magnitude of radiological exposures to workers and safe radiological worker practices are dictated by the Pantex Radiological Control Manual, and ultimately, by 10 CFR 835.

Section 4.14.1.4 contains detailed information about accident mitigation.

Previous PageTable Of ContentsList Of FiguresList Of TablesNext Page



NEWSLETTER
Join the GlobalSecurity.org mailing list