Commissioner George Apostolakis

U.S. Nuclear Regulatory Commission

CmrApostolakis@nrc.gov

PSAM Topical Conference

Tokyo, Japan

April 15, 2013

U.S. NRC ResponseU.S. NRC ResponseU.S. NRC ResponseU.S. NRC Response

to Fukushimato Fukushimato Fukushimato Fukushima

Brief History

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• July 2011 � Near-Term Task Force (NTTF) report issued

• October 2011� NTTF recommendations prioritized into three tiers

�Tier 1 - To be implemented without unnecessary delay

�Tier 2 - Could not be initiated in the near term due to resource or critical skill set limitations

�Tier 3 - Require further NRC study to support a regulatory action

• March 2012 � Tier 1 Orders and requests for information issued

• July 2012� Tier 3 program plans issued

Summary of Regulatory Actions

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• Orders (issued March 2012)

� EA-12-049 – Mitigating strategies for beyond design basis events� EA-12-050 – Hardened vents for Mark I and II containments� Order to be expanded to include severe accident capability by May

2013

� EA-12-051 – Spent fuel pool (SFP) water level instrumentation

• Request for Information (issued March 2012)

� Seismic and flooding walkdowns� Seismic and flooding reevaluations � Emergency Preparedness (EP) staffing and communications

• Rulemakings� Station Blackout Mitigating Strategies� Integration of emergency procedures

Mitigation Strategies Beyond Design Basis External Events

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Requires a three-phase approach for maintaining or restoring core cooling, containment, and spent fuel cooling (industry refers to this as the “FLEX” approach)

Phase Licensee may use

InitialInstalled

equipment

TransitionPortable, onsite

equipment

FinalResources

obtained from offsite

Reliable Hardened Vents

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• March 2012 – issued Order requiring a reliable hardened containment vent system for BWR Mark I and II containments

• Controls containment pressure by removing heat, if normal capability is lost

• May help prevent core damage

• Must be able to function under station blackout (SBO) conditions

Additional Venting Capability

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• March 2013 – Commission directed staff to:

1) Expand the March 2012 Order to require that the reliable hardened vents also be severe accident capable

2) Initiate rulemaking on filtering methods that would minimize releases of radioactive material during an accident� Goes beyond staff recommendation of adding an external filter� Will consider other potential decontamination methods such as

scrubbing through suppression pools or containment spray of radioactive particles

� 4 year completion schedule

Enhanced Spent Fuel Pool Instrumentation

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Requires installation of water level instrumentation to indicate the following levels:

1 – Normal fuel pool level

2 – Below-normal level that still provides radiation shielding

3 – Very low level, near top of fuel racks, where immediate action to add make-up water should be taken

Flood & Seismic Hazard Walkdowns

• Plant walkdowns complete� Reports submitted November 2012

• Issues are being addressed through Corrective Action Programs and the Reactor Oversight Process

• Potential issues identified include:� Procedures that may not be feasible� Temporary flood protection may not perform as planned� Degraded or missing flood protection features (e.g., seals)� Overall, seismic walkdowns did not identify any major concerns

• Sampling of plants will receive audits, expected to be completed by end of July 2013

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Flood Hazard Reevaluations

• First set of plants submitted analyses on March 12, 2013

• Six sites have requested extensions• Some sites included proposed interim actions. NRC

will review and respond by late June 2013 on feasibility of those actions

• Full NRC review of this first set of reevaluations expected by March 2014� As necessary, an integrated flooding

assessment may be required

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Seismic Hazard Reevaluations

No Further Analysis & No Change to Licensing Basis

Industry High FrequencySensitivity Analysis

Phase 2 Licensing Basis Update*

Further EvaluationNeeded

Phase 1Outcome 1

Phase 1Outcome 2

Phase 1Outcome 3

*For new & replacement equipment affected by high frequency GMRS

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• First set of plants due Sept 2013• NRC will review and issue safety

assessments for each site

Seismic Hazard Reevaluation (con’t)

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• Licensee performs seismic PRA� Identify risk contributors� Determine seismic core damage frequency

• Based on results� NRC takes regulatory action, as necessary� NRC Backfit process� Update Licensing Basis

Phase 1Outcome 3

Further Evaluation (Phase 2)

Emergency Preparedness Staffing and Communications

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• Request for Information asked for assessments of staffing needs and communications equipment during multiunit, prolonged SBO events

• Schedule� Phase 1 Communications – October 2012 (complete)� Phase 1 Staffing - April 2013� Phase 2* Staffing and Communications (4 months before 2nd

refueling outage)

*Completion of Phase 2 dependent upon development of Mitigating Strategies

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Rulemaking Activities

• Station Blackout Mitigating Strategies (SBOMS)� NTTF recommended enhancing existing requirements to

account for prolonged SBO� This can be achieved by implementing mitigating

strategies/FLEX� Rule will incorporate insights from implementation of Mitigating

Strategies Order� Mitigating strategies also addresses SFP makeup capability and

resolve those Tier 2 actions� Final Rule December 2016

• Onsite Emergency Response Capabilities� Create a new rule requiring the integration of emergency

procedures� Final Rule February 2016

Tier 2 Recommendations• Spent fuel pool makeup capability:

� Provide safety-related AC electrical power*� Have one train of onsite emergency electrical power operable for SFP makeup

and SFP instrumentation*� Have installed means to add water to the SFP, including an easily accessible

connection to supply water*

• Emergency preparedness: � Have guidance for multiunit dose assessment capability� Hold training and exercises for multi unit and prolonged SBO scenarios*� Practice the identification and acquisition of offsite resources*� Ensure sufficient equipment and facilities exist for multiunit prolonged SBO

scenarios*

• Reevaluation of other external hazards� Request licensees reevaluate external hazards other than seismic and flooding

*Items in green are expected to be addressed under the mitigating strategies Order.

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Tier 3 Recommendations

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• Periodic confirmation of seismic and flooding hazar ds

• Enhanced capability to prevent/mitigate seismically induced fires and

• Reliable hardened vents for other containment desig ns

• Hydrogen control and mitigation inside containment or in other buildings

• EPenhancements for prolonged SBO and multiunit event s

• Improve Emergency Response Data System capability

• Additional EP topics for prolonged SBO and multiuni t events

• EP topics for decision-making, radiation monitoring , and public education

• Reactor Oversight Process modifications to reflect defense-in-depth framework

• Staff training on severe accidents and resident ins pector training on severe accident management guidelines

Additional items added by NRC staff or external sta keholders

• Revisit Emergency Planning Zone Size

• Pre-stage potassium iodide beyond 10 miles

• Transfer of spent fuel to dry cask storage

• Reactor and containment Instrumentation

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NTTF Recommendation 1 –Regulatory Framework

• Staff developing Options for potential changes to the regulatory framework� Industry input/proposal expected April 2013� Substantial additional stakeholder interaction planned� NRC staff developing paper for Commission

Beyond design basis requirements

Risk Management Task Force (NUREG-2150)

Recommendation 1

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Risk Management Task Force(RMTF)

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Task Force formed in February 2011

“To develop a strategic vision and options for adopting a more comprehensive and holistic risk-informed, performance-based regulatory approach for reactors, materials, waste, fuel cycle, and transportation that would continue to ensure the safe and secure use of nuclear material.”

A Proposed Risk ManagementRegulatory Framework

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Decision-Making ProcessUse a disciplined process to achieve the risk management goal:

Identify issueIdentify Options

Analyze

DeliberateImplement

Decision Monitor

MissionEnsure adequate protection of public health and safety, promote the common defense and security, and protect the environment

ObjectiveManage the risks from the use of byproduct, source and special nuclear materials through appropriate performance-based regulatory controls and oversight

Risk Management Goal

maintained acceptably low

Risk Management GoalProvide risk-informed and performance-based defense-in-depth protections

to:� Ensure appropriate barriers, controls, and personnel to prevent, contain,

and mitigate exposure to radioactive material according to the hazard present, the relevant scenarios, and the associated uncertainties; and

� Ensure that the risks resulting from the failure of some or all of the established barriers and controls, including human errors, are maintained acceptably low

Operating Reactor Recommendations

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The set of design basis events/accidents should be reviewed and revised, as appropriate, to integrate insights from the power reactor operating history a nd more modern methods such as PRA.

NRC should establish via rulemaking a design enhancement category of regulatory treatment for beyond-design-basis accidents. This category shoul d use risk as a safety measure, be performance-based (including the provision for periodic updates), inc lude consideration of costs, and be implemented on a sit e-specific basis.

Proposed Regulatory Framework: Power Reactors

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Design basis event?

Adequate protection rule?

Current cost-beneficial safety enhancement rule?

Included risk-important scenario?

Adequate Protection Category

Proposed Design

Enhancement Category

Remaining scenariosProposed Residual

Risk Category

Conclusions

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• NRC implementing safety enhancements at U.S. plants

• No imminent risk from continued operation of U.S. nuclear power plants

• NRC is sharing best practices from lessons-learned implementation with the international community

• NRC continues to evaluate additional lessons learned for applicability to U.S. plants

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U.S. NRC Public website: http://www.nrc.gov/

Find link under Spotlight section called Japan Lessons Learned

More Information