Evaluation basis accidents and beyond evaluation basis accidents have been studied for the secondary and case fabrication operations. The studies postulated a set of accident scenarios that were representative of the risks and consequences for workers and the public that can be expected from operations. Although not all potential accidents were addressed, those that were postulated have consequences and risks that are expected to envelop the consequences and risks of the relocated operations.
A range of hazardous conditions and potential accidents were reviewed as candidates to represent the risks of the facility's operation to workers and the public. Through a screening process, several evaluation basis accidents and beyond evaluation basis accidents were selected for further definition and analysis. A brief description of each of the 12 accident scenarios and source terms is presented below. Table F.2.2.1-1 presents a summary of each accident scenario and source term. Further detail can be found in a topical report (HNUS 1996a).
Scenario 1: Nuclear criticality. Criticality accidents are postulated at nearly all locations where highly enriched uranium (HEU) is handled. Potential causes include operator error and loss of safe geometry resulting from fire damage to aluminum birdcage containers or structural damage from an earthquake. Both ground-level and elevated fission product releases to the atmosphere are postulated. The postulated criticality is based on the characteristics of a solution as specified by the U.S. Nuclear Regulatory Commission.
For the accidental criticality evaluated, it is assumed that 1x1019 fissions occur before reaching a stable, subcritical condition. This total is comprised of an initial burst of 1x1018 fissions followed by repeated bursts of 1x1017 fissions over an 8-hour period as liquid is assumed to be boiled from a solution system. 100 percent of the xenon and krypton formed is released; 25 percent of the iodine is released.
Oak Ridge Reservation. The criticality accident frequency is assumed to be extremely unlikely (1x10-6 to 1x10-4/yr).
Los Alamos National Laboratory. The criticality accident frequency is assumed to be extremely unlikely (1x10-6 to 1x10-4/yr).
Lawrence Livermore National Laboratory. The criticality accident frequency is assumed to be extremely unlikely (1x10-6 to 1x10-4/yr).
Scenario 2: Fire-induced dispersion of highly enriched uranium from a building collapse and resultant fire. The postulated accident assumes that a beyond evaluation basis earthquake causes the uranium process, component fabrication, and storage facilities to collapse. Ruptured gas lines and/or hydraulic lines cause fires in the process and component fabrication facilities.
Oak Ridge Reservation. The frequency of this accident is beyond evaluation basis (1x10-7 to 1x10-6). The total HEU source term released in oxide form is estimated to be 17 kg (37 lb) and 1.5 kg (3.3 lb) of depleted uranium.
Los Alamos National Laboratory. The accident defined for Oak Ridge Reservation (ORR) is assumed to be valid at Los Alamos National Laboratory (LANL). The frequency is assumed to be in the range of 1x10-7 to 1x10-6/yr. The total release is 17 kg (37 lb) of HEU and 1.5 kg (3.3 lb) of depleted uranium. The location of the release is the Chemistry and Metallurgy Research Building.
| Accident Scenario | Site | Accident Frequency (per year) | Total Material Released to Environment |
|---|---|---|---|
| 1. Nuclear criticality | ORR | 1x10-6 to 1x10-4 | 1x1019 fissions |
| LANL | 1x10-6 to 1x10-4 | 1x1019 fissions | |
| LLNL | 1x10-6 to 1x10-4 | 1x1019 fissions | |
| 2. Fire-induced dispersion of highly enriched uranium from a building collapse and resultant fire | ORR | 1x10-7 to 1x10-6 | 17 kg of HEU and 1.5 kg of depleted uranium |
| LANL | 1x10-7 to 1x10-6 | 17 kg of HEU and 1.5 kg of depleted uranium | |
| LLNL | 1x10-7 to 1x10-6 | 17 kg of HEU and 1.5 kg of depleted uranium | |
| 3. Dry criticality resulting from vehicle accident | ORR | 1x10-6 to 1x10-4 | 1x1018 fissions |
| LANL | 1x10-6 to 1x10-4 | 1x1018 fissions | |
| LLNL | 1x10-6 to 1x10-4 | 1x1018 fissions | |
| 4. Fire-induced release of highly enriched uranium from solvent fire | ORR | 1x10-6 to 1x10-4 | 4 kg of HEU |
| LANL | 1x10-6 to 1x10-4 | 4 kg of HEU | |
| LLNL | 1x10-6 to 1x10-4 | 4 kg of HEU | |
| 5. Fire-induced release of highly enriched uranium from metallurgical operations | ORR | 1x10-6 to 1x10-4 | 3.75 kg of HEU |
| LANL | 1x10-6 to 1x10-4 | 3.75 kg of HEU | |
| LLNL | 1x10-6 to 1x10-4 | 3.75 kg of HEU | |
| 6. Fire-induced release of lithium | ORR | 1x10-6 to 1x10-4 | 2,800 kg Li2O |
| LANL | 1x10-6 to 1x10-4 | 2,800 kg Li2O | |
| LLNL | 1x10-6 to 1x10-4 | 2,800 kg Li2O | |
| 7. Fire-induced release of highly enriched uranium on loading dock | ORR | 1x10-6 to 1x10-4 | 0.8 kg of HEU |
| LANL | 1x10-6 to 1x10-4 | 0.8 kg of HEU | |
| LLNL | 1x10-6 to 1x10-4 | 0.8 kg of HEU | |
| 8. Filter failure-induced release of highly enriched uranium | ORR | 1x10-6 to 1x10-4 | 1.6 kg of HEU |
| LANL | 1x10-6 to 1x10-4 | 1.6 kg of HEU | |
| LLNL | 1x10-6 to 1x10-4 | 1.6 kg of HEU | |
| 9. Mechanical release of hydrogen fluoride | ORR | 1x10-6 to 1x10-4 | 386 kg of hydrogen fluoride |
| LANL | 1x10-6 to 1x10-4 | 386 kg of hydrogen fluoride | |
| LLNL | 1x10-6 to 1x10-4 | 386 kg of hydrogen fluoride | |
| 10. Fire-induced release of hydrogen cyanide | ORR | 1x10-6 to 1x10-4 | 300 kg of acetonitrile solvent |
| LANL | 1x10-6 to 1x10-4 | 300 kg of acetonitrile solvent | |
| LLNL | 1x10-6 to 1x10-4 | 300 kg of acetonitrile solvent | |
| HNUS 1996a. | |||
Lawrence Livermore National Laboratory. The accident defined for ORR is assumed to be valid at Lawrence Livermore National Laboratory (LLNL). The frequency is assumed to be in the range of 1x10-7 to 1x10-6/yr. The total release is 17 kg (37 lb) of HEU and 1.5 kg (3.3 lb) of depleted uranium.
Scenario 3: Dry criticality resulting from vehicle accident. A vehicle accident is postulated in which the contents are dislodged and possibly mixed with moderating materials, creating a criticality. HEU oxide powder is spilled and collected in the vehicle's low point. The accidental criticality could be initiated by an error in strapping or by wheels falling off a bottle dolly. The postulated criticality results in 1x10 18 fissions for the dry criticality.
Oak Ridge Reservation. The accident frequency is assumed to be in the range of extremely unlikely (1x10-6 to 1x10-4/yr).
Los Alamos National Laboratory. The accident is assumed to occur at LANL with a frequency of 1x10-6 to 1x10-4/yr.
Lawrence Livermore National Laboratory. The accident is assumed to occur at LLNL with a frequency of 1x10-6 to 1x10-4/yr.
Scenario 4: Fire-induced release of highly enriched uranium from a solvent fire. A fire releasing uranium aerosols is postulated to occur. The types of fires include contaminated trash, solvents containing uranium solutions, uranium chips, and larger uranium metal shapes. A solvent fire releasing uranium-laden combustion gases at ground level is assumed. In this scenario, the entire contents of an extraction column would be released via a pipe break or other failure and are ignited by an electrical fault. Complete combustion would occur.
Oak Ridge Reservation. The release at ORR is estimated to be 4 kg (8.8 lb) of HEU with a frequency in the range of 1x10-6 to 1x10-4/yr.
Los Alamos National Laboratory. The accident is assumed to occur at LANL with a frequency in the range of 1x10-6 to 1x10-4/yr and a release of 4 kg (8.8 lb) of HEU.
Lawrence Livermore National Laboratory. The accident is assumed to occur at LLNL with a frequency in the range of 1x10-6 to 1x10-4/yr and a release of 4 kg (8.8 lb) of HEU.
Scenario 5: Fire-induced release of highly enriched uranium. A uranium fire accident is postulated to occur during metallurgical operations when a 4-liter (L) (1-gallon [gal]) container of briquettes ignites while check weighing before being loaded into a crucible. The total material at risk is estimated to be 15 kg (33 lb) of HEU.
Oak Ridge Reservation. The accident is assumed to occur with a frequency in the range of 1x10-6 to 1x10-4 /yr and a release of 3.75 kg (8.31 lb) of HEU.
Los Alamos National Laboratory. The accident is assumed to occur with a frequency in the range of 1x10-6 to 1x10-4 /yr and a release of 3.75 kg (8.3 lb) of HEU.
Lawrence Livermore National Laboratory. The accident is assumed to occur with a frequency in the range of 1x10-6 to 1x10-4/yr and a release of 3.75 kg (8.31 lb) of HEU.
Scenario 6: Fire-induced release of lithium. A lithium fire is postulated to occur when burning lithium produces hazardous lithium oxide.
Oak Ridge Reservation. The probability of the accident is assumed to be in the range of 1x10-6 to 1x10-4/yr and to release 2,800 kg (6,170 lb) of lithium oxide.
Los Alamos National Laboratory. The probability of the accident is assumed to be in the range of 1x10-6 to 1x10-4/yr and to release 2,800 kg (6,170 lb) of lithium oxide.
Lawrence Livermore National Laboratory. The probability of the accident is assumed to be in the range of 1x10-6 to 1x10-4/yr and to the release 2,800 kg (6,170 lb) of lithium oxide.
Scenario 7: Fire-induced release of highly enriched uranium on loading dock. A uranium metal fire at the loading dock is postulated to occur and results in a release of heated uranium aerosols at ground level. The fire is assumed to burn for 30 minutes and, during that time, completely oxidate the uranium metal in the transport vehicle. The effective release height is estimated to be 30 m (98 ft) because of thermal buoyancy.
Oak Ridge Reservation. The amount of HEU released to the atmosphere is 0.8 kg (1.8 lb) with an assumed frequency in the range of 1x10-6 to 1x10-4/yr.
Los Alamos National Laboratory. The accident is assumed to occur at LANL with a frequency in the range of 1x10-6 to 1x10-4/yr. The release is estimated to be 0.8 kg (1.8 lb) of HEU with a release height of 30 m (98 ft).
Lawrence Livermore National Laboratory. The accident is assumed to occur at LLNL with a frequency in the range of 1x10-6 to 1x10-4/yr. The release is estimated to be 0.8 kg (1.8 lb) of HEU with a release height of 30 m (98 ft).
Scenario 8: Filter failure release of highly enriched uranium. Mechanical upsets are events such as spills, forklift punctures, loss of filtration, and piping failures. The mechanical upset would result in small releases to the atmosphere, unless the off-gas filters in the fluid bed system fail. The bounding accident scenario postulates that both the primary and secondary filters rupture internally, allowing the contained charge of uranium oxide and uranium fluoride particles to be released to the atmosphere via the exhaust stack.
Oak Ridge Reservation. The release to the atmosphere is 1.6 kg (3.5 lb) of HEU from the filter. The assumed accident frequency is in the range of 1x10-6 to 1x10-4/yr.
Los Alamos National Laboratory. The release to the atmosphere is 1.6 kg (3.5 lb) of HEU from the filter. The assumed accident frequency is in the range of 1x10-6 to 1x10-4/yr.
Lawrence Livermore National Laboratory. The release to the atmosphere is 1.6 kg (3.5 lb) of HEU from the filter. The assumed accident frequency is in the range of 1x10-6 to 1x10-4/yr.
Scenario 9: Mechanical release of hydrogen fluoride. This accident is postulated as a large spill of hydrogen fluoride that would generate a dense cloud of hydrogen fluoride that can exceed Level of Concern limits. It is assumed that the entire contents of a tank containing 386 kg (850 lb) of hydrogen fluoride would leak from a 2.54-centimeter (cm) (1-inch [in]) hole, emptying the tank in 12 minutes.
Oak Ridge Reservation. The accident frequency is assumed to range from 1x10-6 to 1x10-4/yr. The release is the tank's entire contents of 386 kg (850 lb) of hydrogen fluoride.
Los Alamos National Laboratory. The accident frequency is assumed to range from 1x10-6 to 1x10-4/yr. The release is the tank's entire contents of 386 kg (850 lb) of hydrogen fluoride.
Lawrence Livermore National Laboratory. The accident frequency is assumed to range from 1x10-6 to 1x10-4/yr. The release is the tank's entire contents of 386 kg (850 lb) of hydrogen fluoride.
Scenario 10: Fire-induced release of hydrogen cyanide during a vehicle impact. A vehicular traffic accident is postulated to occur and cause a rupture in one or more drums containing acetonitrile solvent waste. The spill is ignited by a spark, and the resulting fire spreads to other drums in the area. The fire produces hydrogen cyanide.
Oak Ridge Reservation. The accident frequency is assumed to be in the range of 1x10-6 to 1x10-4/yr. The release involves 300 kg (660 lb) of solvent waste.
Los Alamos National Laboratory. The accident frequency is assumed to be in the range of 1x10-6 to 1x10-4/yr. The release involves 300 kg (660 lb) of solvent waste.
Lawrence Livermore National Laboratory. The accident frequency is assumed to be in the range of 1x10-6 to 1x10-4/yr. The release involves 300 kg (660 lb) of solvent waste.
| Noninvolved Worker at 619 Meters | Maximum Offsite Individual | Population to 80 Kilometers | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Accident Scenario | Dose (rem) | Probability of Cancer Fatality 12 | Dose (rem) | Probability of Cancer Fatalitya | Dose (person-rem) | Cancer Fatalities | Accident Frequency (per year) | ||
| 1. Nuclear criticality | 0.051 | 2.0x10 -5 | 0.051 | 2.5x10 -5 | 3.1 | 1.5x10 -3 | 1.0x10 -5 | ||
| 2. Fire-induced dispersion of highly enriched uranium from a building collapse and resultant fires 13 | 2.4 | 9.6x10 -4 | 2.4 | 1.2x10 -3 | 363 | 0.18 | 5.0x10 -7 | ||
| 3. Dry criticality resulting from vehicle accident | 5.1x10 -3 | 2.0x10 -6 | 5.1x10 -3 | 2.5x10 -6 | 0.31 | 1.5x10 -4 | 1.0x10 -5 | ||
| 4. Fire-induced release of highly enriched uranium from solvent fire | 0.57 | 2.3x10 -4 | 0.57 | 2.9x10 -4 | 86 | 0.04 | 1.0x10 -5 | ||
| 5. Fire-induced release of highly enriched uranium from metallurgical operations | 0.54 | 2.2x10 -4 | 0.54 | 2.7x10 -4 | 80.6 | 0.04 | 1.0x10 -5 | ||
| 7. Fire-induced release of highly enriched uranium on loading dock | 0.083 | 3.3x10 -5 | 0.083 | 4.2x10 -5 | 17.6 | 8.8x10 -3 | 1.0x10 -5 | ||
| 8. Filter failure-induced release of highly enriched uranium | 0.23 | 9.2x10 -5 | 0.23 | 1.1x10 -4 | 34.3 | 0.017 | 1.0x10 -5 | ||
| Impacts for Composite Set of EBAs and BEBAs 14 | |||||||||
| Expected consequences 15 | 1.1x10-4 |
|
1.3x10 -4 |
|
|
0.02 |
|
||
| Expected risk (per year) | 6.4x10 -9 | 8.0x10 -9 | 1.2x10 -6 | ||||||
| Impacts for Composite Set of EBAs | |||||||||
| Expected consequences 15 | 1.0x10-4 |
|
1.2x10-4 | 0.018 | |||||
| Expected risk (per year) | 5.9x10 -9 | 7.4x10-9 | 1.1x10 -6 | ||||||
| Impacts for Composite Set of BEBAs | |||||||||
| Expected consequences15 | 9.7x10-4 | 1.2x10-3 | 0.18 | ||||||
| Expected risk (per year) | 4.9x10-10 | 6.0x10-10 | 9.1x10-8 | ||||||
| Noninvolved Worker at 862 Meters | Maximum Offsite Individual | Population to 80 Kilometers | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Accident Scenario |
Dose (rem) |
Probability of Cancer Fatality 16 |
Dose (rem) |
Probability of Cancer Fatalitya |
Dose (person-rem) |
Cancer Fatalities |
Accident Frequency (per year) |
||
| 1. Nuclear criticality | 0.034 | 1.4x10 -5 | 0.034 | 1.7x10 -5 | 4.9 | 2.4x10 -3 | 1.0x10 -5 | ||
| 2. Fire-induced dispersion of highly enriched uranium from a building collapse and resultant fire 17 | 1.6 | 6.2x10 -4 | 1.6 | 7.7x10 -4 | 360 | 0.18 | 5.0x10 -7 | ||
| 3. Dry criticality resulting from vehicle accident | 3.4x10 -3 | 1.4x10 -6 | 3.4x10 -3 | 1.7x10 -6 | 0.49 | 2.4x10 -4 | 1.0x10 -5 | ||
| 4. Fire-induced release of highly enriched uranium from solvent fire | 0.36 | 1.5x10 -4 | 0.36 | 1.8x10 -4 | 84.5 | 0.042 | 1.0x10 -5 | ||
| 5. Fire-induced release of highly enriched uranium from metallurgical operations | 0.34 | 1.4x10 -4 | 0.34 | 1.7x10 -4 | 79.4 | 0.04 | 1.0x10 -5 | ||
| 7. Fire-induced release of highly enriched uranium on loading dock | 0.053 | 2.1x10 -5 | 0.053 | 2.6x10 -5 | 15.0 | 7.5x10 -3 | 1.0x10 -5 | ||
| 8. Filter failure-induced release of highly enriched uranium | 0.15 | 5.8x10 -5 | 0.15 | 7.3x10 -5 | 33.8 | 0.017 | 1.0x10 -5 | ||
| Impacts for Composite Set of EBAs and BEBAs18 | |||||||||
| Expected consequences 19 | 6.8x10 -5 | 8.4x10 -5 | 0.02 | ||||||
| Expected risk (per year) | 4.1x10 -9 | 5.1x10 -9 | 1.2x10 -6 | ||||||
| Impacts for Composite Set of EBAs | |||||||||
| Expected consequences19 | 6.3x10-5 | 7.9x10-5 | 0.018 | ||||||
| Expected risk (per year) | 3.8x10 -9 | 4.7x10 -9 | 1.1x10 -6 | ||||||
| Impacts for Composite Set of BEBAs | |||||||||
| Expected consequences19 | 6.2x10-4 | 7.7x10-4 | 0.18 | ||||||
| Expected risk (per year) | 3.1x10-10 | 3.9x10-10 | 8.9x10-8 | ||||||
| Noninvolved Worker at 247 Meters | Maximum Offsite Individual | Population to 80 Kilometers | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Accident Scenario | Dose (rem) | Probability of Cancer Fatality20 | Dose (rem) | Probability of Cancer Fatality | Dose (person-rem) | Cancer Fatalities | Accident Frequency (per year) | ||
| 1. Nuclear criticality | 0.07 | 2.8x10 -5 | 0.07 | 3.5x10 -5 | 9.9 | 5.0x10 -3 | 1.0x10 -5 | ||
| 2. Fire-induced dispersion of highly enriched uranium from a building collapse and resultant fire21 | 3.4 | 1.4x10 -3 | 3.4 | 1.7x10 -3 | 1.2x10 3 | 0.58 | 5.0x10 -7 | ||
| 3. Dry criticality resulting from vehicle accident | 7.0x10 -3 | 2.8x10 -6 | 7.0x10 -3 | 3.5x10 -6 | 0.99 | 5.0x10 -4 | 1.0x10 -5 | ||
| 4. Fire-induced release of highly enriched uranium from solvent fire | 0.8 | 3.2x10 -4 | 0.80 | 4.0x10 -4 | 273 | 0.14 | 1.0x10 -5 | ||
| 5. Fire-induced release of highly enriched uranium from metallurgical operations | 0.75 | 3.0x10 -4 | 0.75 | 3.8x10 -4 | 257 | 0.13 | 1.0x10 -5 | ||
| 7. Fire-induced release of highly enriched uranium on loading dock | 0.11 | 4.2x10 -5 | 0.11 | 5.3x10 -5 | 53.2 | 0.027 | 1.0x10 -5 | ||
| 8. Filter failure-induced release of highly enriched uranium | 0.32 | 1.3x10 -4 | 0.32 | 1.6x10 -4 | 109 | 0.055 | 1.0x10 -5 | ||
| Impacts for Composite Set of EBAs and BEBAs22 | |||||||||
| Expected consequences 23 | 1.5x10 -4 | 1.8x10 -4 | 0.063 | ||||||
| Expected risk (per year) | 8.9x10 -9 | 1.1x10 -8 | 3.8x10 -6 | ||||||
| Impacts for Composite Set of EBAs | |||||||||
| Expected consequences23 | 1.4x10-4 | 1.7x10-4 | 0.06 | ||||||
| Expected risk (per year) | 8.2x10 -9 | 1.0x10 -8 | 3.5x10-6 | ||||||
| Impacts for Composite Set of BEBAs | |||||||||
| Expected consequences23 | 1.4x10-3 | 1.7x10-3 | 0.6 | ||||||
| Expected risk (per year) | 6.8x10-10 | 8.5x10-10 | 2.9x10-7 | ||||||
12 Probability (increased likelihood) of cancer fatality to a hypothetical member of the public located at the site boundary or a worker located at the indicated distance from the accident as a result of exposure to the indicated dose if the accident were to occur.
13 A beyond evaluation basis accident (BEBA). All other listed accidents are evaluation basis accidents (EBA).
14 For the offsite population of 1,096,144, the average probability of cancer fatality/risk of cancer fatality (per year) for the composite set of accidents is 1.8x10-8/1.1x10-12.
15 Result of exposure to the indicated dose if the accident occurs. All values are mean values. Model results.
16 Probability (increased likelihood) of cancer fatality to a hypothetical member of the public located at the site boundary or a worker located at the indicated distance from the accident as a result of exposure to the indicated dose if the accident occurred.
17 A beyond evaluation basis accident (BEBA). All other listed accidents are evaluation basis accidents (EBA).
18 For the offsite population of 281,812, the average probability of cancer fatality/risk of cancer fatality (per year) for the composite set of accidents is 7.1x10-8/4.3x10-12.
19 Result of exposure to the indicated dose if the accident occurs. All values are mean values. Model results.
20 Probability (increased likelihood) of cancer fatality to a hypothetical member of the public located at the site boundary or a worker located 247 m (810 ft) from the accident as a result of exposure to the indicated dose if the accident occurred.
21 A beyond evaluation basis accident (BEBA). All other listed accidents are evaluation basis accidents (EBA).
22 For the offsite population of 7,843,061, the average probability of cancer fatality/risk of cancer fatality (per year) for the composite set of accidents is 8.0x10-9/4.8x10-13.
23 Result of exposure to the indicated dose if the accident occurs. All values are mean values.