APPENDIX A
TWRS EIS WASTE INVENTORY DATA

ACRONYMS AND ABBREVIATIONS

DST

EIS

LANL

MUST

SST

TRAC

TWRS

VOC

double-shell tank

Environmental Impact Statement

Los Alamos National Laboratory

miscellaneous underground storage tank

single-shell tank

Track Radioactive Component

Tank Waste Remediation System

volatile organic compounds

NAMES AND SYMBOLS FOR UNITS OF MEASURE, RADIOACTIVITY, AND ELECTRICITY/ENERGY
Length		Area		Volume
cm	centimeter	ac	acre	cm³	cubic centimeter
ft	foot	ft²	square foot	ft³	cubic foot
in	inch	ha	hectare	gal	gallon
km	kilometer	km²	square kilometer	L	liter
m	meter	mi²	square mile	m³	cubic meter
mi	mile			ppb	parts per billion
				ppm	parts per million
				yd³	cubic yard

Mass		Radioactivity		Electricity/Energy
g	gram	Ci	curie	A	ampere
kg	kilogram	MCi	megacurie (1.0E+06 Ci)	J	joule
lb	pound	mCi	millicurie (1.0E-03 Ci)	kV	kilovolt
mg	milligram	Ci	microcurie (1.0E-06 Ci)	kW	kilowatt
mt	metric ton	nCi	nanocurie (1.0E-09 Ci)	MeV	million electron volts
		pCi	picocurie (1.0E-12 Ci)	MW	megawatt
				V	volt
				W	watt

Temperature
C degrees Centigrade
F degrees Fahrenheit

A.1.0 INTRODUCTION

This appendix provides the inventory of waste addressed in this Environmental Impact Statement (EIS). The inventories consist of waste from the following four groups:

Tank waste;
Cesium (Cs) and strontium (Sr) capsules;
Inactive miscellaneous underground storage tanks (MUSTs); and
Anticipated future tank waste additions.

The major component by volume of the overall waste is the tank waste inventory (including future tank waste additions). This component accounts for more than 99 percent of the total waste volume and approximately 70 percent of the radiological activity of the four waste groups identified previously. Tank waste data are available on a tank-by-tank basis, but the accuracy of these data is suspect because they primarily are based on historical records of transfers between tanks rather than statistically based sampling and analyses programs. However, while the inventory of any specific tank may be suspect, the overall inventory for all of the tanks combined is considered more accurate. The tank waste inventory data are provided as the estimated overall chemical masses and radioactivity levels for the single-shell tanks (SSTs) and double-shell tanks (DSTs). The tank waste inventory data are broken down into tank groupings or source areas that were developed for analyzing groundwater impacts.

The waste inventory data in this appendix are from the following documents:

Single-Shell and Double-Shell Tank Waste Inventory Data Package for the Tank Waste Remediation System Environmental Impact Statement (WHC 1995d);
Disposition of Cesium and Strontium Capsules Engineering Data Package for the Tank Waste Remediation System Environmental Impact Statement (WHC 1995h); and
Status Report on Inactive Miscellaneous Underground Storage Tanks (Rasmussen 1995).

A.2.0 WASTE INVENTORY DATA

A.2.1 TANK WASTE INVENTORY

The tank inventory data are presented in Tables A.2.1.1, A.2.1.2, and A.2.1.3. Table A.2.1.1 lists the current waste volumes stored in the SSTs, DSTs, and inactive MUSTs. Table A.2.1.2 lists the chemical constituents in the SSTs and DSTs, and Table A.2.1.3 lists the estimated radionuclide inventory for the SSTs and DSTs. The chemical inventory for the SSTs is categorized by waste types found in the tanks: sludge, saltcake, and liquid. The DST chemical inventory is presented as soluble and insoluble components. The soluble portion of the DST waste inventory was estimated using solubility factors, which were calculated using tank sampling and historical data. These solubility factors represent the amount of each component assumed to be soluble in water. The insoluble portion of the DST waste inventory is assumed to remain in a solid form during sludge washing operations. Data showing the division of the constituents between the soluble and insoluble portion of the SST waste do not exist.

Based on estimates of tritium contained in the tank waste, the Effluent Treatment Facility is expected to process 242-A Evaporator condensate containing 2,360 curies (Ci) of tritium (reflecting decay to December 31, 1999) during its operational life. Processing the wastewater from the K and N Basins would add about 10 percent to this total (DOE 1994e).

A.2.1.1 Tank Aggregated Source Areas

The DSTs and SSTs represent 177 potential sources of contaminant release. These sources were grouped together into source areas (tank groupings) for groundwater modeling purposes. Each tank grouping contains between one and three tank farms. The tank farms were grouped together based on tank configuration , tank proximity, and groundwater flow direction. The inventory from the individual tank farms was then combined to create a waste inventory by source area (Pelton 1995). The SST and DST farms were maintained in separate source areas to support different release scenarios developed for the alternatives. Grouping the tank waste inventory together into source areas, based on tank configuration , geographic proximity, and groundwater flow direction, resulted in eight tank groupings, three in the 200 West Area (two SSTs and one DST) and five in the 200 East Area (three SSTs and two DSTs).

The tank farms were grouped into the source areas identified in Table A.2.1.4 and Figure A.2.1.1. The chemical species and estimated radionuclide inventory for the SST groups are shown in Tables A.2.1.5 and A.2.1.6. The chemical species and estimated radionuclide inventory for the DST groups are shown in Tables A.2.1.7 and A.2.1.8.

A.2.2 CESIUM AND STRONTIUM CAPSULE INVENTORY

The quantities, heat loading, and radioactivity levels for the Cs and Sr capsules are presented in Table A.2.2.1. The chemical form of the Cs in the capsules is cesium chloride (CsCl) and the chemical form of the Sr in the capsules is strontium fluoride (SrF₂). The combined total capsule volume is approximately 2 cubic meters (m³) (70 cubic feet [ft³]) (WHC 1995h).

The Cs content of the capsules is primarily Cs-137, which has a half-life of 30.17 years. Cesium-137 decays into the stable isotope barium-137. The Sr capsules contain mainly Sr-90, which has a half-life of 28.6 years. Strontium-90 decays to yttrium-90 and then to the stable isotope zirconium-90. The reduction in the number of curies, heat load, and concentration over time is due to the radioactive decay of the Cs and Sr into stable daughter products.

A.2.3 INACTIVE MISCELLANEOUS UNDERGROUND STORAGE TANK WASTE INVENTORY

Approximately 40 of the 60 total MUSTs in the Central Plateau that are associated with tank farm operations are inactive MUSTs with inventory that is included in the waste inventory subject to treatment and disposal under the Tank Waste Remediation System (TWRS) (Figures A.2.3.1 and A.2.3.2).

Table A.2.3.1 presents the volume of liquid and solids in the inactive MUSTs (Rasmussen 1995). The total volume of waste in these tanks approximately 448,000 liters (L) (118,000 gallons [gal]), which is less than one-half of 1 percent of the waste volume contained in the SSTs. Definitive characterization data do not exist for the inactive MUSTs, but because they received the same waste products that are contained in the tanks, the concentration of constituents is also expected to be approximately the same.

A.2.4 FUTURE TANK WASTE ADDITIONS

Waste projections for future tank waste additions are shown in Table A.2.4.1. This waste is expected to be added to DSTs after being reduced in water content in the 242-A Evaporator. The majority of the future waste additions would come from decontamination and decommissioning activities at inactive facilities on the Hanford Site. This waste would be classified as dilute, noncomplexed waste (does not contain complexing organics) that are low-level liquid waste. The 100 Area final (terminal) cleanout waste is classified as double-shell slurry feed, which is waste that is concentrated in the evaporator to a point just below the sodium aluminate saturation boundary (Hanlon 1995). Some future tank waste additions may be high-level waste or mixed waste that would come from cleanout of existing Site facilities. These future waste additions would be typical of the types of waste currently stored in the tanks.

The potential relocation of the K Basins sludge to the DSTs would result in the addition of approximately 54 m³ (1,930 ft³) of sludge to these tanks . The sludge contains spent nuclear fuel, corrosion products, small pieces of spent nuclear fuel (primarily uranium), iron oxides and aluminum oxides, concrete grit, fission and activation products from the spent nuclear fuel, and other materials such as sand and dust from the outside environment. The discovery of polychlorinated biphenyls in the sludge may affect the ability of the tank farms to accept the sludge. This waste would add approximately 11,000 Ci to the DSTs. This would include approximately 5,200 Ci of plutonium-241 (Pu-241), 260 Ci of plutonium-239 (Pu-239), 1,280 Ci of Sr-90, and 970 Ci of Cs-137. Following basin cleanout, the sludge plus about 1,200 m³ (43,000 ft³) of water would be transported to the DSTs for waste management, treatment, and disposition.

A.3.0 TANK INVENTORY DATA DISCUSSION

Obtaining representative sample data from the tanks is a very expensive and potentially hazardous activity because the tanks contain high levels of radioactive constituents and because the tank contents are heterogeneous. The SST chemical waste inventory data were derived using historical tank data based on the normalized Track Radioactive Component (TRAC) data. TRAC is a model that was developed to estimate tank waste radioactive inventories. The TRAC model output was later modified to account for known processing parameters and was then identified as normalized TRAC data.

The DST chemical and radiological waste inventories were developed using tank sample data in combination with historical tank data. DST radionuclide estimates were based on existing laboratory data and characterization reports. The isotopes presented in this appendix for DSTs were those consistently reported by laboratories, which is why the number of isotopes reported for DSTs is different than SSTs.

The waste inventory data used in developing the alternatives and their associated impacts were derived from model predictions and sample analysis. While the waste is currently undergoing additional characterization and the inventory may be revised as a result of ongoing analyses, the inventory used in the EIS is not expected to result in the discrimination for or against any of the alternatives presented.

There is considerable uncertainty associated with these inventory data. Additional tank characterization is required before final design of any alternative can take place. However, for the purposes of conceptual design, the concept of a nominal waste feed stream based on overall tank waste inventory can be used to develop plant capacities, project plant performance, and provide initial equipment sizing. The use of a nominal feed allows each of the proposed alternatives to be developed conceptually to a point where they can be analyzed in this EIS. This approach does not preclude the need for additional characterization.

A.3.1 OTHER TANK CHARACTERIZATION PROGRAMS

Several ongoing activities are involved with collecting and analyzing data on tanks contents. Each of these efforts is an attempt to provide more detailed and accurate tank waste inventory data. The following are ongoing programs:

Tank Characterization Program - Sampling and analysis of tank waste;
Los Alamos National Laboratory (LANL) - Historical estimates based on observed waste stream data and process knowledge to develop inventory; and
Historical Tank Content Estimates - Compiling available historical data.

The Tank Characterization Program, further addressed in Appendix B, gathers waste samples from each of the tanks for analysis. This program, which is based on data needs, is responsible for collecting and analyzing tank waste to satisfy the data requirements for tank safety issues and remediation process design. Ongoing waste characterization program activities to improve the estimates for tank waste inventory include 1) waste sampling and laboratory analysis; 2) data interpretation; and 3) historical review. The historical review provides a basis and background in data interpretations on waste management activities.

The LANL waste characterization effort consists of a series of spreadsheet-based computer models that derive composition estimates for the waste streams distributed to the tanks. When reconciled with the waste transaction records, these waste streams will provide an estimated accounting of the waste present in each tank as a function of time. Initial indications are that these model estimates, in their current form, are moderately successful in predicting certain bulk waste properties and inventories (WHC 1994f). Initial modeling results have been completed for all of the SSTs (solids inventory only) and DSTs. This program is ongoing, with plans to develop the model for the tank farm operations to track the tank waste inventory.

The Historical Tank Content Estimates are a series of documents being prepared by the current Management and Operations contractor that combine available historical tank data with the characterization data estimated by LANL (Agnew 1994). These documents will compile the tank waste volumes, photographs, temperatures, waste types, and waste inventory estimates over time (WHC 1994g, h, and WHC 1995b, o). Historical Tank Content Estimates have been initially released for all of the SSTs and DSTs. This is an ongoing program and current planning includes updating these documents during 1996.

A.3.2 LOS ALAMOS NATIONAL LABORATORY TANK WASTE CHARACTERIZATION DATA

The estimation of tank contents using the LANL model is expected to be completed by October 1996. At present, the LANL model has been used to estimate the composition of the solids (sludge plus saltcake) in the SSTs, and the composition of the solids and liquid in the DSTs. There are enough data from the LANL model to make a comparison with the inventory data package that is used in the EIS (WHC 1995d). Tables A.3.3.1 and A.3.3.2 compare the metric tons of chemicals and the metric tons or curies of radionuclides that are reported for the inventory data package and the LANL model (Agnew 1994, WHC 1994g, h, and WHC 1995b, o). The comparison of chemical constituents is limited to those chemicals that are common to both inventories. The comparison of radionuclides is restricted to those that are reported for the LANL model.

A general comparison of the amounts reported by the LANL model and the data package shows that the LANL model routinely reports amounts that are several times greater than the corresponding amounts from the data package. This result is observed for both chemicals and radionuclides. However, when the LANL model reports are complete, the total differences may be less. The derivation of the LANL model and the generation of the inventory data are both sufficiently complex that the source of the differences between the two are not readily explained. However, it is possible to address the two inventory sources in the light of their effect on the EIS. The EIS uses inventories as the basis for calculating risks, both during the remediation phase of the alternatives and during the post-remediation phase. Risks during remediation arise primarily from releases to the atmosphere. Risks during post remediation are caused by releases to groundwater.

Risks during remediation are caused primarily from exposure to Cs-137, Sr-90, iodine-129 (I-129), and carbon-14 (C-14) for radionuclides and volatile organic compounds (VOCs) for chemicals. The LANL model shows only Cs and Sr, so it cannot be used to calculate the risks for I-129 and C-14. The LANL model indicates a Cs content in the SSTs that is over four times that reported in the data package. In the case of Sr, the LANL model indicates twice as much in the DSTs than the data package reports. Neither the LANL model nor the data package report VOCs, so another data source was used for these chemicals. If data from the LANL model were used for the EIS, calculations would show somewhat higher risks during remediation because of increased Cs and Sr quantities.

Risks during post remediation are caused by mobile elements migrating through groundwater. The mobile radionuclides of concern are C-14, I-129, technetium-99 (Tc-99), and uranium. The mobile chemical constituent of concern is the nitrate anion. The LANL model only indicates quantities for uranium and nitrate. Quantities are not shown for C-14, I-129, and Tc-99 for the LANL model, so no differences from currently projected impacts could be calculated. The LANL model indicates about 20 percent more uranium in the SSTs than the inventory data package shows. For the DSTs, the inventory data package does not indicate any uranium in the DSTs, while the LANL model shows 160 metric tons. For total uranium in both SSTs and DSTS, the LANL model indicates about 30 percent more uranium than the inventory data package shows. In the case of nitrate quantities, the inventory data package shows about twice as much in the SSTs than the LANL model shows. Both estimates are essentially equal for nitrate in the DSTs. The effect of using quantities estimated by the LANL model for the EIS would be to indicate marginally higher risks in post remediation caused by uranium and somewhat lower risks caused by nitrate.

A.3.3 TANK INVENTORY DATA ACCURACY AND ITS EFFECT ON THE EIS

The predicted inventories from different models will not necessarily be in agreement with regards to the kinds and quantities of substances that make up the tank wastes. There is an ongoing effort to compile a standard inventory estimate that would serve as a unified source of tank constituents (WHC 1995q). These best-basis estimates are to be incorporated into the existing Tank Characterization Database. However, this work is in its initial stages and completion is expected at a future date. Until this unified source has been completed and is universally used, other documents, such as the EIS, must use available inventory data and recognize the effects of inaccuracies in those data. This section presents the effects of inventory data accuracy on the various portions of the EIS.

An important point to keep in mind when considering inventory data accuracy is the ultimate significance of the data as they are used to calculate or predict environmental impacts. For a substance that is present in minute quantities and is not radioactive or toxic, high accuracy in reporting that substance in the tank inventory is not required. The effects of variation in the amount of such a benign substance would not be great. Conversely, if a substance is a major tank waste constituent, or is highly radioactive or very toxic, the accuracy in reporting that substance and the ultimate effect on environmental impacts must be recognized. For example, sodium is a major waste component and its quantities will affect the size of the low-activity waste facility for the ex situ alternatives. However, the pre-conceptual estimation of the size and cost of facilities for the EIS has a variation that is typically plus or minus 40 percent. This variation in size and cost estimation is based on factors that include the variability of the feed stock. A variation in sodium quantities by plus or minus 20 percent would not produce environmental effects that were unexpected.

Rather than discuss the effects of inventory accuracy on an element-by-element basis, this section presents the measures that were taken by each function or discipline to account for the variability of the tank waste inventory. These measures must strike a balance between understating environmental impacts and overstating these impacts by compounding conservatism upon conservatism. In addition to the discussion in this section, each appendix contains the major assumptions and uncertainties, which include other factors in addition to uncertainties in tank inventory data.

Engineering

To provide conservatism in generating inventory information for use by other disciplines, the engineering function used the inventory data package as the basis for conservative estimates of the releases during retrieval and subsequent processing; the dissolution of the residual materials remaining in the tanks and the low-activity waste vaults; and the effects of blending and composition on the volume of high-level waste glass or calcine. Releases from the tanks during ongoing current operations were obtained directly from analytical data , which do not involve concentration modeling. The data relating to these releases were used directly, with no additional conservative factors being applied.

Groundwater Modeling

The inventories generated by the engineering function were used without change by the groundwater modeling function. To ensure that groundwater effects were not understated, conservative values of distribution coefficients (K_d) were used. While this would not affect the inventory of contaminants, it would ensure that the travel times of contaminants were at the upper bound of the range that is generally accepted for these studies. While other assumptions were made to complete the groundwater modeling, they did not directly involve the contaminant inventory.

Air Modeling

The model inputs used by the air modeling function were the routine emissions from the tank farms and emissions from the remediation facilities. The air modeling function used the analytical results from ongoing current operations to predict the concentrations of contaminants that would be released from the tank farms. The emissions from the remediation facilities were provided by the engineering function (Jacobs 1996). The analytical results from current tank farm operations were obtained by direct measurement and were considered to be sufficiently accurate for use without modification. Emissions from remediation facilities are directly related to the tank inventories because it is the tank contents that are being processed. Because the models that predict air contaminant concentrations are considered sufficiently conservative, the calculated emissions from the remediation facilities were used without further modification.

Risk Assessment

Inventory data were used to calculate risks from routine exposures and accidents during remediation and post-remediation activities. The assessment of risk from routine exposures during remediation used the same inputs as the air modeling function. As explained in the previous paragraph, the analytical results from ongoing operations of the tank farms and the calculated emissions from the remediation facilities were used. Because the results of the groundwater modeling were used as input to the assessment of risk during post remediation, the conservatism employed by groundwater modeling was directly reflected in the risk assessment modeling. Consequently, further conservative assumptions concerning the contaminant concentrations were not postulated.

The accepted practice for assessing risks from accidents during remediation combines the overall inventory of contaminants, both modeled and analyzed, to form the contents of a so-called super tank. This is a unique use of the tank inventory and is intended to ensure that the consequences of accidents invariably involve exposures to the same quantities of contaminants. This concept is used solely for accident analysis and is consistent with current Hanford Site practice. The assessment of risks during post remediation uses the conservative estimate of the volume and inventory of the high-level waste glass or calcined product, which has been provided by the engineering function. The models that calculate the consequences of transportation accidents are considered sufficiently conservative, and the inventory provided by the engineering function is used without modification.

Figure A.2.1.1 Location of the Tank Waste Source Areas

Figure A.2.3.1 Inactive Miscellaneous Underground Storage Tank Locations - 200 East Area

Figure A.2.3.2 Inactive Miscellaneous Underground Storage Tank Locations - 200 West Area

Table A.2.1.1 Tank Waste Volumes¹

Table A.2.1.2 Estimated Mass of Nonradioactive Chemical Components of SST and DST Waste in Metric Tons ^1,
2

Table A.2.1.3 Estimated Radionuclide Inventory for SSTs and DSTs in Curies ^{1, 2}

Table A.2.1.4 Tank Source Areas

Table A.2.1.5 Estimated Mass of Nonradioactive Chemical Components of SSTs by Aggregated Tank Grouping in Metric Tons ^{1, 2}

Table A.2.1.6 Estimated Radionuclide Inventory for Aggregated SST Groupings in Curies ^{1, 2, 3}

Table A.2.1.7 Estimated Mass of Nonradioactive Chemical Components by Aggregated DST Grouping

Table A.2.1.8 Estimated Radionuclide Inventory for Aggregated DST Groupings in Curies ^{1, 2, 3}

Table A.2.2.1 Characteristics of Existing Capsules

Table A.2.3.1 Inactive MUSTs Estimated Current Waste Volumes in Liters ¹

Table A.2.4.1 Future Post Evaporator DST Waste Projections

Table A.3.3.1 Comparison of Reported Quantities of Chemicals in Metric Tons

Table A.3.3.2 Comparison of Reported Quantities of Radionuclides

REFERENCES

Agnew 1994. Agnew, S.F. Hanford Defined Wastes: Chemical and Radionuclide Compositions. LA-UR-94-2657. Los Alamos National Laboratory. Los Alamos, New Mexico. August 1994.

DOE 1994e. Tritiated Wastewater Treatment and Disposal Evaluation for 1994. DOE/RL-94-77. U.S. Department of Energy. Richland, Washington. August 1994.

Hanlon 1996 . Hanlon, B.M. Waste Tank Summary for Month Ending February 29, 1996. WHC-EP-0182-95. Westinghouse Hanford Company. Richland, Washington. April 1996.

Hanlon 1995. Hanlon, B.M. Waste Tank Summary for Month Ending December 31, 1994.

WHC-EP-0182. Westinghouse Hanford Company. Richland, Washington. February 1995.

Jacobs 1996. Engineering Calculations for the Tank Waste Remediation System Environmental Impact Statement. Jacobs Engineering Group Inc. Kennewick, Washington. April 1996.

Pelton 1995. Pelton, M. Database Manager and Health Physicist, Advanced Sciences, Inc. Personal Communication. Richland, Washington. January 27, 1995.

Rasmussen 1995. Rasmussen, J.E. Status Report on Inactive Miscellaneous Underground Storage Tanks. Attachment Letter to D. Sherwood (EPA) and M. Wilson (Ecology). U.S. Department of Energy. Richland, Washington. June 9, 1995.

WHC 1995b. Historical Tank Content Estimate for the Northwest Quadrant of the Hanford 200-West Area. Work Order E11728. WHC-SD-WM-ER-351, Rev. 0. Westinghouse Hanford Company. Richland, Washington. March 1995.

WHC 1995d. Single-Shell and Double-Shell Tank Waste Inventory Data Package for the Tank Waste Remediation Environmental Impact Statement. WHC-SD-WM-EV-102, Rev. 0. Westinghouse Hanford Company. Richland, Washington. July 1995.

WHC 1995h. Disposition of Cesium and Strontium Capsules Engineering Data Package for the Tank Waste Remediation System Environmental Impact Statement. WHC-SD-WM-DP-087, Rev. 0. Westinghouse Hanford Company. Richland, Washington. July 1995.

WHC 1995o. Historical Tank Content Estimate for the Southeast Quadrant of the Hanford 200 Area. WHC-SD-WM-ER-350, Rev. 0. Westinghouse Hanford Company. Richland, Washington. June 1995.

WHC 1994f. Tank Characterization Reference Guide. WHC-SD-WM-TI-648, Rev. 0. Westinghouse Hanford Company. Richland, Washington. September 1994.

WHC 1994g. Historical Tank Content Estimate for the Northeast Quadrant of the Hanford 200 East Area. WHC-SD-WM-ER-349, Rev. 0. Westinghouse Hanford Company. Richland, Washington. June 1994.

WHC 1994h. Historical Tank Content Estimate for the Southwest Quadrant of the Hanford 200 West Area. WHC-SD-WM-ER-352, Rev. 0. Westinghouse Hanford Company. Richland, Washington. June 1994.

WHC 1995q. Work Plan for Defining a Standard Inventory Estimate for Wastes Stored in Hanford Site Underground Tanks. WHC-SD-WM-WP-311, Rev. 0. Westinghouse Hanford Company. Richland, Washington. September 1995.

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APPENDIX ATWRS EIS WASTE INVENTORY DATA