1. Breakout Session V: Mitigation Strategies for Beyond Design Basis External Events (NTTF Recommendation 4.2) Fukushima Regulatory Response Workshop April 5, 2012

2. Overview  Background  Site Assessment Process (Doug True)  Procedural Implementation (David Gambrell)  Reasonable Protection (Bryan Miller)  Regional Response Centers (Dave Fuller)  ANPR on Station Blackout (Bryan Ford)  Q&A 2

3. FLEX Mitigation Strategies  Provide diverse, flexible means to prevent fuel damage (core and SFP) while maintaining containment function  Employs a three phase approach: 1.Initially cope by relying on installed plant equipment, 2.Transition from installed plant equipment to onsite FLEX equipment, 3.Obtain additional capability and redundancy from offsite equipment until power, water, and coolant injection systems are restored or commissioned. 3

4. Site Assessment Process 4

5. Initial Boundary Conditions  Beyond design basis external event occurs impacting all units at site,  All reactors on site initially operating at power, unless site has procedural direction to shutdown due to the impending event,  Each reactor is successfully shutdown when required (i.e., all rods inserted, no ATWS),  Onsite staff are at site administrative minimum shift staffing levels,  No independent, concurrent events, e.g., no active security threat, and  All personnel onsite are available to support site response. 5

6. Extended Loss of AC Power (ELAP) - Initial Conditions -  No specific initiating event is used. Loss of off-site power (LOOP) to all units on site with no prospect for recovery of offsite power for many days.  All installed sources of emergency onsite AC power and SBO Alternate AC power sources are assumed to be not available and not imminently recoverable.  Cooling and makeup water inventories contained in systems or structures with robust designs are available.  Ultimate heat sink water inventory remains available.  Diesel fuel oil stored in robust structures remains available.  Portable equipment that is reasonably protected has predetermined hookup strategies can be used.  Installed electrical distribution system remain available provided they are protected consistent with current station design.  No additional events are assumed to occur immediately prior to or during the extended loss of AC power, including security events. 6

7. Step 1 – Baseline Coping Capability  Guidance leverages off of NUMARC 87-00  Build off of prior work on IER 11-4  Addresses reactor core cooling, spent fuel cooling, containment  Guidance addresses: – Key assumptions – Loss of ventilation – Personnel habitability – Minimum instrumentation – Key elements of plant-specific procedures 7

8. Step 1 – Baseline Coping Capability (Cont.)  Key features: – Strategies designed for at-power events, but portable equipment required to be available for all modes – N+1 sets of onsite portable equipment and supplies – Strategies employing portable equipment have primary and alternate connection points – Strategies are to achieve stable condition that can be re-supplied by regional response centers and do not include steps to recover and restore damaged functions 8

9. BWR Baseline Capability Summary 9 Safety FunctionMethodBaseline Capability Core Cooling Reactor Core Cooling RCIC/HPCI/IC Depressurize RPV for Injection with Portable Injection Source Sustained Source of Water Use of installed equipment for initial coping Primary and alternate connection points for portable pump Multiple means to depressurize RPV Use of alternate water supply to support core and SFP heat removal Key Reactor Instrumentation RPV Level RPV Pressure (Re-)Powered instruments Other instruments for plant-specific strategies Containment Containment Pressure Control /Heat Removal Containment Venting or Alternative Containment Cooling Consistent with Recommendation 5.1 or other capability. Key Containment Instrumentation Containment Pressure Suppression Pool Temperature Suppression Pool Level (Re-)Powered instruments SFP Cooling Makeup with Portable Injection Source Makeup via hoses on refuel deck Makeup via connection to SFP makeup piping SFP Instrumentation SFP Level Per Rec 7.1 Support Electric Power Portable AC/DC Supplies As needed Other Support Communications equipment Hoses, couplings, connectors, tools, supplies, lighting, etc. Procedures/Guidance As needed

10. PWR Baseline Capability Summary 10 Safety FunctionMethodBaseline Capability Core Cooling Reactor Core Cooling & Heat Removal AFW/EFW Depressurize SG for Makeup with Portable Injection Source Sustained Source of Water Use of installed equipment for initial coping Connection for portable pump to feed all SGs Use of alternate water supply to support core and SFP heat removal RCS Inventory Control Low Leak RCP Seals or RCS makeup required All Plants Provide Means to Provide Borated RCS Makeup Site choice on low-leak RCP seals or providing onsite RCS makeup capability Diverse makeup connections to RCS for long- term RCS makeup > Key Reactor Instrumentation SG Level SG Pressure RCS Pressure RCS Temperature (Re-)Powered instruments Containment Containment Pressure Control/Heat Removal Containment Spray Connection point on containment spray header for use with offsite pump or analysis demonstrating that containment pressure control is not challenged Key Containment Instrumentation Containment Pressure (Re-)Powered instruments consistent SFP Cooling Makeup with Portable Injection Source Makeup via hoses on refuel deck Makeup via connection to SFP makeup piping SFP Instrumentation SFP Level Per Recommendation 7.1 Support Electric Power Portable AC/DC Supplies As needed Other Support Communications equipment Hoses, couplings, connectors, tools, supplies, etc. As needed Procedures/Guidance

11. Step 2 – Applicability of External Event “Stress Tests” 11 Hazard ClassApplicability Considerations Seismic  All sites must assess beyond design basis seismic events External flooding  Variability in design basis considerations  Potential for large source floods at site  Margin in current external flood design basis Storms with High Winds (Hurricanes, tornadoes, etc.)  Coastal sites exposed to hurricanes/large storms  Regional history with tornadoes Snow, Ice, Low Temperatures  Regional experience with extreme snow, ice, and low temperatures Extreme High Temperatures  Regional experience with extreme high temperatures

12. Step 2A – Seismic Stress Test  Applicability: – All plants  Protection: – Reasonable structural protection (discussed later) – Large portable equipment anchored to prevent damage – Location away from potential seismic hazards  Deployment: – Transportation route – Connection point – Non-robust downstream dams – Power/motive force to move equipment 12

13. Step 2A – Seismic Stress Test (Cont.)  Procedural interfaces: – Alternate means of key parameter indication – Impact of floods from non-robust water sources – Loss of UHS level, if downstream dam applies  Interface with Offsite Resources: – Staging area and routes for supplies 13

14. Step 2B – Flooding Stress Test  Applicability: – Screening process based on current design basis and relevant flood hazards  Stress test considers – Warning time – Flood persistence on a site-specific basis.  Many sites expected screen “in” 14

15. Step 2B – Flooding Stress Test (Cont.)  Protection: – Consider warning time to allow relocation or storage well above flood level  Deployment: – Credit for plant shutdown and staging/alignment of FLEX equipment when warning time warrants – Movement/restocking/fuel impacts – Viability of connection points – Instrumentation impacts – Storm impacts, as applicable 15

16. Step 2B – Flooding Stress Test (Cont.)  Procedural interfaces: – Incorporation of FLEX into existing external flood procedures, as appropriate – Use of alternate connection points, if needed  Interface with Offsite Resources: – Impacts on staging and delivery 16

17. Step 2C – Severe Storms with High Winds Stress Test  Applicability: – Based on susceptibility to tornadoes and hurricanes  Protection: – Structure for reasonable protected (later) – Separation for tornado sites  Deployment: – Staging and preparation – UHS impacts – Debris removal  Procedural interfaces: – Interface with hurricane procedures, as applicable  Interface with Offsite Resources: – Impacts on staging and delivery 17

18. Step 2D – Snow, Ice, and Extreme Cold Stress Test  Applicability: – Sites with regional experience with such events  Protection: – Reasonable structural protection (discussed later) – Temperature effects on timely deployment  Deployment: – Procured to function in expected environment – Snow/ice removal equipment – UHS impacts from ice/frazil ice 18

19. Step 2D – Snow, Ice, and Extreme Cold Stress Test (Cont.)  Procedural interfaces: – Transportation impacts  Interface with Offsite Resources: – Site access and staging 19

20. Step 2E – High Temperature Stress Test  Applicability: – All sites  Protection: – No impact  Deployment: – Impact on equipment functionality  Procedural interfaces: – Only related to equipment operation  Interface with Offsite Resources: – Equipment capable of functioning in high temperatures 20

21. Step 3 – Implementation Plan and Programmatic Controls  Aggregate the considerations for the baseline and stress test cases to define viable site-specific strategies  Establish reasonable protection and programmatic controls  Confirm compatibility with equipment to be provided by regional response centers – Regional equipment – Compatible connections 21

22. FLEX Procedure Strategy NEI Workshop April 6, 2012

23. Procedure Task Team Status  TT formed to develop procedure strategy for FLEX  TT Members representation – BWROG and PWROG Procedure Committees – Utilities for each Reactor type  Developed a consensus basis document  Developed an executive recommendation  Recommendation under Steering Committee and CNO (NSIAC) review  Necessary requirements to be included in NEI FLEX Guide 23

24. Objective PROBLEM STATEMENT  The existing plant-specific procedure hierarchies (EOPs, EDMGs, SAMGs, etc.) may not provide adequate interfaces to effectively maintain or restore core cooling and containment and spent fuel pool cooling capabilities under the circumstances associated with external hazards resulting in extended loss of all AC power or loss of ultimate heat sink capability. FLEX PROCEDURE OBJECTIVE  Development of a procedural approach for coping with beyond-design- basis events (Rec 4.2) that interfaces between the various accident mitigating procedures so that overall strategies are coherent and comprehensive (Rec 8.1). 24

25. Approach  Consider Basic Structure Options – Insertion into existing procedure sets – Utilization of support procedure set(s) – Separate/Complete procedure set  Consider Significant Inputs/Impacts StaffingTraining QualityMRule 50.5950.54 (x), (y) 25

26. Procedure Options 26

27. Procedure Considerations 27

28. Procedural Approach  Create FLEX support guidelines (FSGs) to implement Beyond-Design- Basis-Event strategies  Existing AOP, EOP, SAMG, EDMGs retain “command and control” functions and be revised only to the extent necessary to: – Incorporate modified strategies for performing functions within their respective command and control – Establish criteria for utilization of FSGs in lieu of permanent plant equipment  The FSGs may be used to support SAMGs or EDMGs  Training (via SAT process) should be based on assessment of frequency, importance and difficulty  FLEX equipment is proposed to be exempt from Mrule. 28

29. Reasonable Protection and Programmatic Controls NEI Workshop April 6, 2012

30. Reasonable Protection  FLEX equipment shall be stored such that no one external event can reasonably fail the site FLEX capability (N). 30

31. Reasonable Protection  Multiple storage options – Existing safety-related or equivalent structures – New or existing structures built to or evaluated equivalent to ASCE 7-10, Minimum Design Loads for Buildings and Other Structures – Other existing structures – Outdoors 31

32. Reasonable Protection  Additional Considerations – Different FLEX equipment can be credited for independent events – Credit can be taken for relocating FLEX equipment to protect it from external events that are predictable – Transport from storage location following external event must be considered – FLEX equipment can be permanently staged if reasonably protected 32

33. Reasonable Protection  Guidance Document – General guidance is provided in Section 11 – Event specific guidance is provided in the applicable section 33

34. Programmatic Considerations  Augmented Quality comparable to that used for SBO  Documented basis required for: – mitigation strategies – preventative maintenance and testing program – reasonable protection  Maintenance Rule would not apply to portable equipment 34

35. Regional Response Centers NEI Workshop April 6, 2012

36. Regional Response Centers  The U.S. Industry’s goal is to have a more effective integrated response to future events.  One aspect of this integrated response is the need to establish Regional Response Center(s) (RRC) 36

37. Regional Response Centers  Mission – have the capability to respond to a nuclear station’s request to provide stored equipment to their site in two waves: twenty four (24) hour seventy two (72) hour 37

38. Regional Response Centers  Next Steps – Award contract August 2012 – Stand up Response Center(s) December 2012 38

39. Advanced Notice of Proposed Rulemaking NEI Workshop April 6, 2012

40. ANPR on Station Blackout  ANPR Issued March 20, 2012  Comments Due May 4, 2012  Developing new SBO requirements and their regulatory basis  Looking at many of the issues being addressed by FLEX – Should SBO equipment be designed to withstand severe natural events the facility is not already designed for? 40

41. ANPR on Station Blackout  NRC Subcommittee Established – Team Meeting April 11 – Issue draft comments to industry April 19 – Comments due from industry April 24 – NRC Meeting April 25 – Issue Letter to NRC May 4  Send Comments to bford@entergy.com 41

42. QUESTIONS? 42