1 An Introduction to the Headquarters Operations Center and RASCAL Kevin Quinlan Physical Scientist, NRO U.S. Nuclear Regulatory Commission October 21 – 23, Nuclear Utilities Meteorological Data Users Group (NUMUG)

2 Nuclear Security and Incident Response (NSIR) Mission & Vision NSIR Mission To prevent nuclear security incidents and prepare for and respond to safety and security events NSIR Vision To be a valued partner in homeland security and national emergency preparedness and response

3 Response Framework National Response Framework Nuclear/Radiological Incident Annex NRC Incident Response Plan 24/7 Emergency Operations Center Exercises, training, and stakeholder outreach

4 Emergency Responsibilities Licensee: –Mitigate the accident and its consequences –Properly classify and notify off-site officials of the event –Prepare and communicate Protective Action Recommendations (PARs) to State and local officials

5 Emergency Responsibilities State / Local Officials: –Activate resources –Evaluate the licensee’s Protective Action Recommendation(s) –Implement appropriate protective actions

6 Emergency Responsibilities Members of Public: –Heed warnings / orders to take timely and appropriate action to minimize radiation exposure and adverse health effects

7 NRC’s Responsibilities Assess plant conditions Evaluate Protective Action Recommendations Support off-site officials Keep other agencies informed Keep news media informed

8 Coordination With Other Agencies Department of Homeland Security Department of Defense Federal Aviation Administration Department of Energy Environmental Protection Agency Department of Justice Federal Emergency Management Agency States / Locals

9 Classification of Emergencies Notification of Unusual Event –An event that indicates potential degradation in the level of safety of the plant Alert –Loss of a vital system or barrier Site Area Emergency –Loss of a vital safety function General Emergency –Severe core damage accident

10 NRC Response Modes Based upon NRC’s independent assessment: Normal Mode Monitoring Mode Activation Mode Expanded Activation Mode

11 Operations Center Staffing HQ Operations Officers and Emergency Response Officers staff the HQ Operations Center 24/7 to receive and assess all incoming information, coordinate event-related communications, and facilitate a fast startup of the NRC incident response organization if conditions warrant.

12 Introduction to RASCAL Radiological Assessment System for Consequence AnaLysis (RASCAL) Evaluates releases from: –Nuclear Power Plants –Spent Fuel Storage Pools and Casks –Fuel Cycle Facilities –Radioactive Material Handling Facilities

13 RASCAL Developers Van Ramsdell Battelle – Pacific NW National Laboratory Steve McGuire U.S. Nuclear Regulatory Commission George Athey Athey Consulting

14 Model a variety of processes from source term to dose WIND Dry deposition Wet deposition Plume– mix of radionuclide gases and particles Source term released to atmosphere

15 Model doses at locations away from the release point Groundshine (external) Cloudshine (external) Inhalation (internal)

16 Meteorological Data Needed for RASCAL Needed to model the behavior of the radioactive plume in the atmosphere Minimum required data: –Wind speed & direction: downwind transport –Stability: plume horizontal and vertical growth –Precipitation: wet deposition

17 Sources of Meteorological Data Emergency Response Data System (ERDS) at nuclear power plants National Weather Service Local ASOS Stations Predefined Meteorological Data

18 Predefined Meteorological Data 18 data sets covering a range of common weather conditions (e.g., Summer - Afternoon - Windy) Pros –Can be used with any location and any date and time of release –Quick and easy to use, especially when no actual obs available –No need to run Meteorological Data Processor program Cons –Wind fields are uniform in space –Do not consider topography –Fixed wind direction of 270 degrees –Do not include any diurnal variations.

19 Limits of ERDS Meteorological Data No forecast information May not be connected when needed Single location data may not be sufficient to describe winds in complex terrain

20 Two Transport and Diffusion Models Straight-line Plume Model -- Polar Grid –Used close in –Nodes close together near release point –Plume centerline always passes over nodes Puff Model -- Cartesian Grid –Used further out –Plume (Puff) centerline may not pass directly over nodes

21 Polar Grid for Plume Model Used for close-in calculations 8 concentric circles 10 degree separation Release at center Model is steady state Distances from center may be set by the user

22 Puff Movement 41 x 41 receptor points Lagrangian puff model Time must be allowed for material transport time Puff center moves with winds Puff grows larger as it travels Used for points farther from source

23 Long-range dispersion modeling RASCAL results are reasonably good to at least 10 miles RASCAL calculates to 50 miles, but with diminished accuracy NARAC and NOAA models provide longer range atmospheric dispersion calculations

24 Meteorological Data Field Display

25 Total Equivalent Dose Estimation

26 Maximum Dose Values

27 Who will be running models and how should they interpret the results? NRC, States, Utility, DHS, NARAC It’s only a computer model Each model is different – that can be a good thing; Don’t get hung up on the differences Be aware of the underlying assumptions, limitations, and usefulness of the models

28 Questions