NRC’s Modeling Needs and Capabilities for Effective Emergency Response

1. NRC’s Modeling Needs and Capabilities for Effective Emergency Response Stephen A. McGuire Incident Response Operations US Nuclear Regulatory Commission (301) 415-6204 sam2@nrc.gov

2. Chronology of ResponseEarly Phase - Nuclear Power Plants • Significant malfunction detected by plant instruments • Licensee declares emergency based on pre-established criteria • Licensee notifies State first, NRC second

3. Chronology of ResponseEarly Phase - Nuclear Power Plants • NRC makes decision on whether to staff it’s Emergency Operations Center • Staffing could be as small as 3-4 people or up to 80 • Staffing should be largely complete in less than an hour

4. Chronology of ResponseEarly Phase - Nuclear Power Plants • Communications links established and information collected • Dose models will be run to determine appropriate protective actions for the public (e.g. evacuation, sheltering) • The State makes the decision on whether to order protective actions • NRC has advisory role

5. Chronology of ResponseIntermediate Phase - Nuclear Power Plants • This phase starts after the plume has passed • Need to know whether relocation is necessary due to deposited radionuclides, whether interdiction of crops is necessary, and where there are decontamination needs

6. Chronology of Response Intermediate Phase - Nuclear Power Plants • Models should indicate the path of the plume and deposition patterns • However, the need for protective actions will be determined primarily by field measurements • FRMAC has the primary responsibility for making and analyzing field measurements

7. Chronology of ResponseFuel Cycle / Radioactive Materials / Transportation • Released quantities of radionuclides much smaller • Often release would have taken place before NRC Emergency Operations Center staffed

8. Chronology of ResponseFuel Cycle / Radioactive Materials / Transportation • Licensee expected to notify local officials and recommend protective actions based on the nature of the accident • Each accident type has a predetermined protective action that was based on modeling of the release

9. Necessary Model Features for NRC Emergency Response • Built-in source term module • Built-in dose projection capability • Rapid runtime (minutes) • Easy to use by occasional users • Appropriate range (usually 10 miles) • Must model dry and wet deposition • Must model radiological decay and buildup in transit

10. Current NRC Dose Model • NRC has developed the RASCAL code to generate radiological source terms, estimate atmospheric transport and diffusion, and calculate doses to potentially exposed people • NRC had already identified the needed criteria for it’s modeling needs and developed the RASCAL code to meet the needs

11. RASCAL Descriptors

12. RASCAL Descriptors

13. RASCAL Descriptors