E.12.0 NO ACTION ALTERNATIVE (CAPSULES)
The No Action alternative for Cs and Sr capsules would involve the continued operation of Waste Encapsulation and Storage Facility (WESF) for 10 years. This section analyzes potential operation and transportation risks resulting from accidents associated with this alternative. Because there would be no construction, accidents associated with construction were not analyzed.
E.12.1 TRANSPORTATION ACCIDENTS
Employee Vehicles
Personnel required to support the various activities would drive to the site in their vehicles. The total person-years to support the alternative for 10 years was calculated to be 1.00E+03 (Jacobs 1996). Each person is assumed to work 260 days of the year. The round-trip distance traveled to work from the Tri-Cities area is estimated at 140 km (87 mi) with an estimated 1.35 passengers per vehicle (DOE 1994a). The total personnel vehicle distance was therefore calculated as follows:
(1.00E+03 person-years) · (260 days/year) · (140 km/day) · (1/1.35 person) = 2.70E+07 km (1.68E+07 mi)
The expected numbers of injuries and fatalities resulting from employee vehicle accidents were calculated as follows:
Injuries = (2.70E+07 km) · (7.14E-07 injuries/km) = 1.93E+01
Fatalities = (2.70E+07 km) · (8.98E-09 fatalities/km) = 2.42E-01
E.12.2 OPERATION ACCIDENTS
The potential exists for accidents resulting from operation activities, which are discussed in Appendix B. The potential accidents were identified in the document entitled Potential Accidents for Storage and Disposition of Cesium and Strontium Capsules for the Tank Waste Remediation System-EIS (WHC 1995k). The data package provided a range of potential accidents, probability of the accidents, and the consequences of the accidents. These accidents are summarized in the Accident Screening Table (Table E.12.2.1 ). The dominant accident scenario analyzed in the following subsection was selected from the table.
E.12.2.1 Pool Cell Storage Accident at the Waste Encapsulation and Storage Facility
Types of potential accidents associated with pool cell storage at WESF are leaks, direct exposure, fires, mechanical impacts, and explosions. From Table E.12.2.1 , the DBA accident identified as having the highest risk would be an earthquake that would result in the combination of Accident 3.1.2 "loss of shielding in a single pool cell," and Accident 3.1.1, "strontium capsule leak."
E.12.2.1.1 Scenario and Source-Term Development for Pool Cell Storage Accident
It was postulated that the earthquake results in the roof of the building collapsing breaching 40 Sr capsules. The pool cell is also breached and all the water drained from the cell. The source-term resulting from the breached canisters for the noninvolved worker receptor as calculated in the capsule data package (WHC 1995k) would be 1.2E-01 Ci based on 8 hours exposure. The general public was calculated to be 3.5E-01 Ci based on 24 hours exposure. In addition to the source-term, the loss of the water shielding the capsules would result in high direct radiation doses to the receptors. It was assumed that all workers would die in the building from the collapsed roof.
Table E.12.2.1 Accident Screening Table for the No Action Alternative (Capsules)
E.12.2.1.2 Probability of Pool Cell Storage Accident
The initiating event is a beyond design basis earthquake with an annual exceedance frequency of 2.5E-04 per year. Based on an operation duration of 10 years, the probability of the event would be 2.5E-03.
E.12.2.1.3 Radiological Consequence of Pool Cell Storage Accident
The radiological dose to the receptors from the previous source-term was calculated by the GENII computer code (Napier et al. 1988) using the methodology previously discussed in Section E.1.1.6.
The direct radiation dose to the receptors from the accident scenario was calculated using the Monte Carlo Neutron Photon (MCNP) computer code. Because the pools are belowground, the primary source of dose rates to people outside the facility would be due to radiation scattering (often referred to as shine) from the air. The results, which are taken from the potential accident data package for the capsules (WHC 1995k), are summarized in Table E.12.2.2.
TableE.12.2.2 Dose Consequence for Pool Cell Storage Accident
E.12.2.1.4 Radiological Cancer Risk for Pool Cell Accident
To calculate the LCFs and the LCF risk (point estimate) for the receptors, a dose-to-risk conversion factor of 4.0E-04 LCF per person-rem for the noninvolved worker and MEI noninvolved worker and 5.0E-04 for the general public and MEI general public was used. The results are presented in Table E.12.2.3. Aside from the 10 workers dying from the collapsed roof, the calculations show there would be no fatal cancer.
E.12.2.1.5 Chemical Consequences for Pool Cell Accident
Chemical consequences were not evaluated in (WHC 1995k) since the small quantity of nonradiological constituents in the capsules would result in an exposure to all receptors well below the cumulative ratio of 1.0 to ERPG-1 values for toxic or corrosive/irritant chemicals.
E.12.2.2 Occupational Fatalities and Injuries
Table E.12.2.3 Latent Cancer Fatality Risk from Pool Cell Accident
The number of operation personnel was estimated at approximately 1.00E+03 person-years (Jacobs 1996). The number of injuries, illnesses, and fatalities for the 10 years of operation are calculated as follows:
Total Recordable Cases = (1.00E+03 person-years) · (2.2E+00 incidences/100 person-years) = 2.2E+01
Lost Workday Cases = (1.00E+03 person-years) · (1.1E+00 incidences/100 person-years) = 1.1E+01
Fatalities = (1.00E+03 person-years) · (3.2E-03 fatalities/100 person-years) = 3.2E-02
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