Fukushima Fukushima Dai Dai-ichi ichi Accident Accident Michael - - PowerPoint PPT Presentation

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Nov 02, 2022 497 likes •707 views

Briefing on Briefing on the Status of the Status of Lessons Learned Lessons Learned from the from the Fukushima Fukushima Dai Dai-ichi ichi Accident Accident Michael Johnson Deputy Executive Director for Reactor and Preparedness

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Briefing on Briefing on the Status of the Status of Lessons Learned Lessons Learned from the from the Fukushima Fukushima Dai Dai-ichi ichi Accident Accident

Michael Johnson Deputy Executive Director for Reactor and Preparedness Programs May 17, 2016

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Evolution of Fukushima Activities Evolution of Fukushima Activities

Near-Term Task Force Report on Fukushima Dai-ichi Accident Three Orders and Request for Information Implementation Following NRC-Endorsed Industry Guidance Safety Evaluations and Verification of Compliance Continued Oversight of Safety Enhancements Gaining insights and enhancing approaches 2011 Today 2012

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SLIDE 3

Recommendation Status

Ensuring Protection from External Events

2.1 – Reevaluation of seismic & flooding hazards Ongoing 2.2 – Periodic reconfirmation of hazards Ongoing 2.3 – Seismic & flooding hazard walkdowns Closed Other – Reevaluate other external hazards Ongoing

Enhancing Mitigation of Beyond-Design-Basis Events

4.1 – Mitigation of beyond design basis events rulemaking* Ongoing 4.2 – Mitigation of beyond design basis events order Ongoing 5.1 – Severe accident capable hardened vents order Ongoing 5.2 – Vents for other containment designs Closed 6 – Hydrogen control and mitigation Closed 7.1 – Reliable spent fuel pool instrumentation Ongoing 7.2- 7.5 – Spent fuel pool water makeup capability* Ongoing

Strengthening Emergency Preparedness for Multi- Unit Events

8.1-8.4 – Onsite emergency response capabilities* Ongoing 9.1-9.4 – Rulemaking to enhance emergency plans* Ongoing 10.1-10.2 – Analyze and evaluate other EP considerations* Ongoing 10.3 – Evaluate ERDS capabilities Closed 11.2&11.4 – Decision-making and public education Closed

Regulatory Philosophy

1 – Reassess regulatory framework Closed 12.1 – Include defense in depth requirements within ROP Closed 12.2 – Enhance staff training on severe accidents & SAMGs Closed

Radiological Consequences

11.3 – Real time radiation monitoring within EPZ Ongoing Other – Containment vent filters/filtering strategies Closed Other – Expand EPZ size beyond 10 miles Closed Other – Pre-stage KI to residents beyond 10 miles Closed Other – Expedited transfer of spent fuel to dry storage Closed

    

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*Integrated into MBDBE rulemaking due by end of 2016

A Comprehensive Approach

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SLIDE 4

Speakers Speakers

  • Jack Davis, Director, Japan Lessons-

Learned Division (JLD)

– Overall Progress and Update on Tier 1 Activities

  • Mohamed Shams, Chief, Hazards

Management Branch, JLD

– Seismic and Flooding Hazard Reevaluations

  • Gregory Bowman, Deputy Director, JLD

– Resolution of Tier 2 and 3 Recommendations

  • Troy Pruett, Director, Division of Reactor

Projects, Region IV

– Long-term Oversight

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SLIDE 5

*For illustrative purposes only

Implementation On/Ahead of Schedule

Today

Mitigating Strategies Spent Fuel Pool Instrumentation Hardened Vents Walkdowns Seismic Reevaluations Flooding Reevaluations Staffing & Communication Mitigation of Beyond Design Basis Events

Containment Protection/Release Reduction

Orders 50.54(f) Requests Rule- making 2012

~70 units in compliance by Summer 2016 ~92 units in compliance by Summer 2016

2013 2014 2015 2016 2017 2018 2019 2020

Closed Closed

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Tier 2&3

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SLIDE 6

Comments Received on Comments Received on Mitiga Mitigation of Beyond tion of Beyond-Design Design- Basis Events Proposed Rule Basis Events Proposed Rule

  • Improve clarity in the use of the term

“loss of all ac”

  • Remove requirement for multiple

source term dose assessment

  • Clarify use of risk insights for

addressing reevaluated hazards

  • Establish process to define when

changes require prior NRC approval

  • Allow flexibility with implementation

timeframes

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SLIDE 7

Closure of Seismic and Flooding Closure of Seismic and Flooding Hazard Re Hazard Reviews views

Reevaluated Seismic/Flooding Hazards Update plans/ additional inspection No additional action Yes Further Regulatory Action? Closeout

  • Rec. 2.1

Mitigation Strategies Assessments Changes? No 50.54(f) Letter Assessments Screen Out? Yes No

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SLIDE 8

Significant Progress in Hazard Significant Progress in Hazard Reevaluation Reevaluation

Seismic Flooding

Hazard Reevaluation Reports Received (100%) Hazard Reevaluation Reports Received (93%) Acknowledgement Letters Issued (100%) Hazard Acceptability Letters Issued (84%) Expedited Approach Received (100%) Interim Actions Received (93%) Expedited Approach Response (97%) Interim Actions Inspected (85%) Staff Assessments Issued (95%) Staff Assessments Issued (25%)

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SLIDE 9

Flooding Action Plan Flooding Action Plan Implem Implementa entation is on Tra tion is on Track ck

Hazard Acceptance Review Mitigation Strategies Assessments

(Majority of sites in 2016)

Focused Evaluations Integrated Assessments Regulatory Actions (Phase 2)

De Develop elop Guidance Guidance Saf Safety Enhancement ety Enhancements 2016 2016-2017 Mid-2017 2018

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SLIDE 10

Seismic Hazard Reevaluation is Seismic Hazard Reevaluation is

  • n Sch
  • n Schedule

edule

Hazard Acceptance Review

(Complete)

Mitigation Strategies Assessment Interim Actions (Complete CEUS, 2016 WUS) High-Frequency Evaluation Spent Fuel Pool Evaluation Seismic Probabilistic Risk Assessment

Phase 2 Decisions

Implement G Implement Guidance uidance Saf Safety Enhancements ety Enhancements

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SLIDE 11

Status Summary of Tier 2 and 3 Status Summary of Tier 2 and 3 Recommendations Recommendations

3 Enhanced capability to prevent/mitigate seismically-induced fires & floods 5.2 Reliable hardened vents for other containment designs 6 Hydrogen control and mitigation inside containment or in other buildings 9.3 ERDS capability throughout accident (partial) 10 Additional EP topics for prolonged SBO and multiunit events (partial) 11 EP topics for decision-making, radiation monitoring, and public education (partial) 12.1 Reactor Oversight Process modifications to reflect Defense in Depth framework 12.2 Staff training on severe accidents and resident inspector training on SAMGs

  • Expedited transfer of spent fuel to dry cask storage
  • Revisit emergency planning zone size & pre-stage potassium iodide beyond 10 miles
  • Reactor and containment instrumentation

7.2 – 7.5 Spent fuel pool makeup capability 9.1/9.2 EP enhancements for prolonged SBO and multiunit events 9.3 Emergency preparedness (partial) 9.4 Improve ERDS capability 10 Additional EP topics for prolonged SBO and multiunit events (partial) 11 EP topics for decision-making, radiation monitoring, and public education (partial)

  • Reevaluation of external hazards other than seismic and flooding

2.2 Periodic confirmation of external hazards 11 EP topics for decision-making, radiation monitoring, and public education (partial)

Subsumed in Tier 1 Further Assessment Closed

Resolv esolved ed

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SLIDE 12

ACRS: Assess need to enhance instrumentation to survive beyond-design-basis events

Closed Closed – Evaluat Evaluation ion of

  • f

Instrumentation Instrumentation Enhancemen Enhancements ts

Tier 3  Further staff study; dependent on higher-priority recommendations Summary of Final Evaluation

  • Tier 1 enhancements and existing requirements.
  • Insights from MBDBE rulemaking analyses.
  • Ongoing work to develop consensus standard.
  • Addressed comments from ACRS and stakeholders.
  • Added information on SAMG principles/approaches.
  • Conclusion – No additional regulatory action necessary.

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SLIDE 13

Summary of Final Evaluation

  • Significant information from previous/ongoing studies.
  • EA-13-109 in progress for Mark I and II containments.
  • Mitigating strategies for all containment designs.
  • Addressed comments from ACRS and stakeholders.
  • Added insights from ongoing SOARCA study.
  • Conclusion – No additional regulatory action necessary.

Closed – Evaluation of Vents for Other Containment Designs

5.2: Reevaluate the need for hardened vents for other containment designs Tier 3  Dependent on insights from Tier 1 activities (Order EA-13-109 and related rulemaking)

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SLIDE 14

6: Identify insights about hydrogen control and mitigation inside containment or in other buildings

Closed Closed – Evaluat Evaluation ion of Hydr

  • f Hydrogen
  • gen

Control Control and Mitigation and Mitigation

Tier 3  Dependent on insights from Tier 1 activities and further evaluation Summary of Final Evaluation

  • Existing requirements in 10 CFR 50.44.
  • Significant information from previous studies.
  • EA-12-049 and EA-13-109 enhance safety.
  • Addressed comments from ACRS and stakeholders.
  • Added insights from ongoing SOARCA study.
  • Conclusion – No additional regulatory action necessary.

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SLIDE 15

Group Group 3 Recommen 3 Recommendation dations Are s Are On Schedule On Schedule

  • Ongoing analysis to address the

following recommendations:

– Evaluation of other external hazards – Periodic confirmation of external hazards – Real-time radiation monitoring in EPZs and

  • n-site
  • Results of external hazard screening to

Commission by end of May 2016

  • Goal to resolve all remaining Tier 2&3

recommendations by the end of 2016

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SLIDE 16

Post-Compliance Inspections

  • NRC conducted on-site audits during

evaluation of licensees’ plans

  • NRC safety evaluations capture staff’s

assessment

  • Temporary Instruction 191 is being

used to verify compliance

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SLIDE 17

Results of Initial Inspections

  • Temporary Instruction 191

results

  • No findings of significance

identified

  • Issues addressed in

corrective action programs

  • All issues discussed with

cross-regional panel

  • Inspection activity increases

in 2017

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SLIDE 18

Future Oversight Plans

  • Transition plan has been crafted
  • Continue to develop and use normal

agency processes

  • Address lessons learned from

Temporary Instruction 191 inspections

  • Collaboration on training and

information sharing

  • Finalize oversight program for National

SAFER Response Centers and Severe Accident Management Guidelines

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SLIDE 19

Path Forward for Completing Lesson-Learned Initiatives

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  • Significant progress has been achieved

– Majority of safety benefit will be in place by end of 2016

  • Additional work is needed to closeout

Fukushima lessons learned

  • Continued engagement with

stakeholders

  • Consistent with international

community

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SLIDE 20

Acronyms Acronyms

AC Alternating Current KI Potassium-Iodide ACRS Advisory Committee

  • n Reactor Safeguards

MBDBE

Mitigation of Beyond Design Basis Events CEUS Central and Eastern United States NRC Nuclear Regulatory Commission CFR Code of Federal Regulations ROP Reactor Oversight Process EA Enforcement Action SAMG Severe Accident Management Guidelines EP Emergency Preparedness SAFER Strategic Alliance for FLEX Emergency Response EPZ Emergency Planning Zone SBO Station Blackout ERDS Emergency Response Data System

SOARCA State-of-the-Art Reactor

Consequence Analyses JLD Japan Lessons- Learned Division WUS Western United States

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