ML071910037
| ML071910037 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 07/11/2007 |
| From: | Wang A NRC/NRR/ADRO/DORL/LPLIV |
| To: | Keenan J Pacific Gas & Electric Co |
| Wang, A B, NRR/DORL/LPLIV, 415-1445 | |
| Shared Package | |
| ML071910029 | List: |
| References | |
| EA-02-026, TAC MD4527, TAC MD4528 | |
| Download: ML071910037 (12) | |
Text
July 11, 2007 Mr. John S. Keenan Senior Vice President and Chief Nuclear Officer Pacific Gas and Electric Company Diablo Canyon Power Plant P.O. Box 770000 San Francisco, CA 94177-0001
SUBJECT:
DIABLO CANYON POWER PLANT, UNIT NOS. 1 AND 2 - CONFORMING LICENSE AMENDMENTS TO INCORPORATE THE MITIGATION STRATEGIES REQUIRED BY SECTION B.5.b. OF COMMISSION ORDER EA-02-026 (TAC NOS. MD4527 AND MD4528)
Dear Mr. Keenan:
This letter documents the results of the U.S. Nuclear Regulatory Commission (NRC) staffs regulatory assessment of the adequacy of the actions taken by the Pacific Gas and Electric Company for the Diablo Canyon Power Plant, Units 1 and 2, in response to Section B.5.b. of the February 25, 2002, Interim Compensatory Measures (ICM) Order (EA-02-026) and related NRC guidance.
The ICM Order was issued following the events of September 11, 2001, as part of a comprehensive effort by the NRC, in coordination with other government agencies, to improve the capabilities of commercial nuclear reactor facilities to respond to terrorist threats. Section B.5.b. of the Order required licensees to develop specific guidance and strategies to maintain or restore core cooling, containment, and spent fuel pool cooling capabilities using existing or readily available resources (equipment and personnel) that could be effectively implemented under the circumstances associated with loss of large areas of the plant due to explosions or fire, including those that an aircraft impact might create. Although it was recognized prior to September 11, 2001, that nuclear reactors already had significant capabilities to withstand a broad range of attacks, implementing these mitigation strategies would significantly enhance the plants capabilities to withstand a broad range of threats. It should be noted that portions of the ICM Order, as well as other documents referenced in this letter, contain security-related or safeguards information, and are not publicly available.
Licensee actions to implement Section B.5.b mitigation strategies have been ongoing since the issuance of the 2002 ICM Order. In 2005, the NRC issued guidance to more fully describe the NRC staffs expectations for implementing Section B.5.b of the ICM Order. The NRC guidance relied upon lessons learned from detailed NRC engineering studies and industry best practices.
Additionally, the NRC conducted two on-site team assessments at each reactor facility that identified additional mitigating strategies for preservation of core cooling, containment integrity, and spent fuel pool cooling. In total, these efforts have added defense in depth through the use of additional equipment and strategies. Moreover, these enhancements that have strengthened the interface between plant safety and security operations now include fire-fighting response strategies; plant operations to mitigate fuel damage; and actions to minimize releases.
J. S. Keenan The enclosed Safety Evaluation (SE) details the interactions between the NRC staff and the Pacific Gas and Electric Company, as well as the rest of the nuclear industry, related to the final resolution of Section B.5.b. of the ICM Order.
The NRC is incorporating requirements for the B.5.b mitigating strategies into the Facility Operating Licenses. This letter, therefore, also transmits the license condition that captures the ICM Order Section B.5.b mitigation strategy requirements and incorporates them into the licensing basis.
This proposed license condition was transmitted by the NRC to the Pacific Gas and Electric Company in a letter dated October 26, 2006. By letter dated January 11, 2007, the Pacific Gas and Electric Company informed the NRC staff that it would accept the proposed license condition, with a minor change that the NRC staff finds acceptable. The effectiveness of the licensees actions to implement the mitigative strategies contained in this license condition will be subject to future NRC review and inspection.
Consistent with the Order, administrative license changes to Facility Operating License Nos. DPR-80 and DPR-82 for the Diablo Canyon Power Plant, Unit Nos. 1 and 2, respectively, are being made to incorporate the agreed upon license condition. These changes comply with the standards and requirements of the Atomic Energy Act of 1954, as amended, and the Commission's rules and regulations set forth in Title 10 of the Code of Federal Regulations (10 CFR) Chapter I. Please replace the affected pages of the Facility Operating Licenses with the enclosed pages (Enclosure 1).
The attachments to the SE are designated exempt from public disclosure under 10 CFR 2.390(d)(1) since they contain security-related information and are Official Use Only.
If you have any questions, please contact me at (301) 415-1445.
Sincerely,
/RA/
Alan B. Wang, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-275 and 50-323
Enclosures:
- 2. Safety Evaluation cc w/o atts to Encl. 2: See next page
Pkg ML071910029 (Letter & Encl 2: ML071910037, Encl 1: ML071910214, Attachments to SE (OUO): ML071800458)
OFFICE NRR/LPLIV/PM NRR/PSPB/LA NRR/DPR/PSPB NRR/LPIV/PM NRR/LPIV/BC NAME MFields DBaxley DNelson AWang THiltz DATE 7/10/07 7/10/07 7/10/07 7/11/07 7/11/07 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO ORDER NO. EA-02-026 PACIFIC GAS AND ELECTRIC COMPANY DIABLO CANYON POWER PLANT, UNITS 1 AND 2 DOCKET NOS. 50-275 AND 50-323
1.0 INTRODUCTION
1.1 Purpose The purpose of this Safety Evaluation (SE) is to document the U.S. Nuclear Regulatory Commission (NRC) staffs regulatory assessment of the adequacy of the actions taken by the Pacific Gas and Electric Company (the licensee) in response to the February 25, 2002, Interim Compensatory Measures (ICM) Order and the subsequent NRC letter to licensees dated February 25, 2005, transmitting NRC guidance (Phase 1 guidance document). This SE describes the basis for finding licensee strategies adequate to satisfy the requirements of the ICM Order. This SE also discusses the license condition that satisfactorily captures the mitigation strategy requirements. If the licensee makes future changes to its strategies within its commitment management program, this SE will be useful to the NRC staff in determining if the changed strategies are adequate to meet the license condition. It should be noted that portions of the ICM Order, as well as other documents referenced in this SE, contain security-related or safeguards information, and are not publicly available.
1.2 Background The February 25, 2002, ICM Order that imposed interim compensatory measures on power reactor licensees required in Section B.5.b, Mitigative Measures, the development of specific guidance and strategies to maintain or restore core cooling, containment, and spent fuel pool cooling capabilities using existing or readily available resources (equipment and personnel) that can be effectively implemented under the circumstances associated with loss of large areas of plant due to explosions or fire. These actions were to be implemented by the end of August 2002. Inspections of the implementation of the Section B.5.b requirements were conducted in 2002 and 2003 (Temporary Instruction (TI) 2515/148). The inspections identified large variabilities in scope and depth of the enhancements made by licensees. As a result, the NRC determined that additional guidance and clarification was needed for nuclear power plant licensees.
Subsequent to the conduct of the TI 2515/148 inspections, engineering studies conducted by the NRC Office of Regulatory Research (RES) provided insights into the implementation of
mitigation strategies to address the loss of large areas of a plant due to explosions or fire, including those that an aircraft impact might create. The NRC actions resulting from these studies included: (1) inspections of licensee actions that address plant-specific consequences, (2) issuance of advisories that involve processes and protocols for licensee notification of an imminent aircraft threat, and (3) identification of mitigative measures to enhance plant response to explosions or fire.
On November 24, 2004, the NRC issued a letter to licensees providing information on the Commissions phased approach for enhancing reactor mitigative measures and strategies for responding to Section B.5.b of the ICM Order. On February 25, 2005, the NRC issued guidance (Phase 1 guidance document) to describe more fully the NRC staffs expectations for implementing Section B.5.b of the ICM Order. Determination of the specific strategies required to satisfy the Order, elaborated on by the Phase 1 guidance document, was termed Phase 1.
Further information on the Commissions phased approach and its reliance on the Phase 1 guidance document and related workshop was described in an NRC letter to licensees dated January 14, 2005.
The NRC Phase 1 guidance document relied upon lessons learned from recent NRC engineering studies involving plant assessments, as well as industry best practices. This guidance also included the spent fuel pool mitigative measures described in a NRC letter to licensees dated July 29, 2004, Issuance of Spent Fuel Pool Mitigative Measures. These best practices were identified during the inspections conducted in 2002 and 2003. The Phase 1 guidance document also incorporated industry comments made at two B.5.b-related workshops held on January 14, 2005, and February 2, 2005.
2.0 REGULATORY EVALUATION
Section B.5.b of the ICM Order required licensees to develop specific guidance and strategies to maintain or restore core cooling, containment, and spent fuel pool cooling capabilities using existing or readily-available resources (equipment and personnel) that can be effectively implemented under the circumstances associated with loss of large areas of the plant due to explosions or fire. Determination of the specific strategies required to satisfy the Order, elaborated on in the Phase 1 guidance document, was termed Phase 1.
In order to assure adequate protection of public health and safety and common defense and security, the NRC determined that differences in plant design and configuration warranted independent assessments to verify that the likelihood of damage to the reactor core, containment, and spent fuel pools and the release of radioactivity is low at each nuclear power plant. The Commission directed the NRC staff to conduct site-specific security and safety assessments to further identify enhanced mitigation capabilities. Site-specific assessments of spent fuel pools was deemed Phase 2 and site-specific assessments of reactor core and containments was deemed Phase 3.
The goal of the Phase 2 and 3 mitigation strategy assessments was for the NRC and the licensees to achieve a new level of cognition of safety and security through a comprehensive understanding of the capabilities and limitations of the plants under normal, abnormal, and severe circumstances (from whatever cause). Based on this improved understanding, licensees could take reasonable steps to strengthen their capabilities and reduce their
limitations. The NRC expected that safety and security would be well served by further enhancing the licensees severe accident management strategies for mitigating a wide spectrum of events through the use of readily-available resources and by identifying potential practicable areas for the use of beyond-readily-available resources.
During 2005, the NRC staff performed inspections (TI 2515/164) to determine licensees' compliance with Section B.5.b of the ICM Order (Phase 1). Subsequent meetings were held with licensees to resolve identified open issues. Confirmatory B.5.b Phase 1 inspections (TI 2515/168) were conducted during the period of June to December 2006. The NRC staff conducted site visits as part of the Phase 2 assessments during 2005. In 2006, the NRC staff observed licensee Phase 3 studies and conducted independent Phase 3 assessments.
On January 24, 2006, the Nuclear Energy Institute (NEI) submitted a letter (M. Fertel to L. Reyes) describing an industry proposal for resolving (closing) Phase 2 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML060260220). The industry proposed high level functional mitigating strategies for a spectrum of potential scenarios involving spent fuel pools. In a letter to all Holders of Licenses for Operating Power Reactors dated June 21, 2006 (ADAMS Accession No. ML061670146), the NRC accepted the Phase 2 proposal pending review of site-specific details of its application and implementation.
In arriving at this conclusion, the NRC staff placed significant weight on portions of the proposal that rely on industry commitments to provide beyond-readily-available resources not previously available. These additions will significantly enhance licensees mitigating strategies capabilities.
On June 27, 2006, the NEI submitted two letters (M. Fertel to W. Kane). In one of the letters, the NEI proposed a license condition to capture the Section B.5.b requirements and addressed items deferred from Phase 1 to Phase 2 (ADAMS Accession No. ML061790400). The license condition includes 14 items in the same broad categories as the February 25, 2005, Phase 1 guidance document; fire fighting response strategy, plant operations to mitigate fuel damage, and actions to minimize releases. The proposal suggested that the implementing details found to be an acceptable means of meeting the license condition would be treated as commitments, and managed in accordance with NEI 99-04, Guidelines for Managing NRC Commitment Changes. In the second letter, the NEI proposed generic strategies for closure of Phase 3 (ADAMS Accession No. ML061860753). The required strategies for all three phases would be covered by the license condition and all implementing details would be managed by NEI 99-04.
The February 25, 2005, Phase 1 guidance document included 34 expectations. Two of these items were deferred to Phase 2 and seven items (i.e., six expectations and one element of a seventh expectation) were deferred to Phase 3. The NRC staff reached agreement with licensees on the non-deferred items under Phase 1.
Table 1 provides a cross reference of how the 34 elements of the February 25, 2005, Phase 1 guidance document and Phases 2 and 3 mitigating strategies correspond to the sections of the license condition.
On June 29, 2006, the NRC staff issued a letter to the NEI conditionally accepting its proposed license condition and strategies (ADAMS Accession No. ML061790306). The letter reiterated that mitigation strategies in NEIs proposals that were identified during the Phase 2 and 3 assessments, which utilize reasonable, evident, readily-available resources (as identified in the
February 25, 2005, Phase 1 guidance document) are required pursuant to Section B.5.b of the ICM Order. The implementing details of the required strategies will be implemented by commitment and managed in accordance with the NEI commitment management guideline, NEI 99-04. The NRC staff believes the NEI proposal reasonably justifies excluding from formal regulatory controls those additional strategies identified during the site-specific Phases 2 and 3 assessments that the NRC previously deemed required under Section B.5.b of the ICM Order, but not identified in NEIs proposals. Inherent in this conclusion is recognition of the addition of beyond-readily-available resouces included in the proposals. The implementing details of mitigation strategies included in the proposal, including those that utilize beyond-readily-available resources, will be treated as commitments, which will become part of the licensing basis of the plant. Additional strategies identified during site-specific assessments which licensees deem acceptable and valuable to promote diversification and survivability, will be incorporated into licensees Severe Accident Management Guidelines, Extreme Damage Mitigation Guidelines, or appended to other site implementation guidance. To verify compliance, the NRC staff evaluated the site-specific implementation and documentation of the proposed Phases 2 and 3 mitigating strategies for each U.S. nuclear power plant.
3.0 TECHNICAL EVALUATION
The NRC staffs technical evaluation for strategies identified in Phase 1 of Section B.5.b is found in Appendix A. The NRC staffs technical evaluation for strategies identified in Phases 2 and 3 of Section B.5.b is found in Appendix B.
The Mitigating Strategies Table (MST) is included as Appendix C. The purpose of the MST is to capture, at the functional level, a summary of licensee strategies for compliance with the 34 measures presented in the February 25, 2005, Phase 1 guidance document and to indicate how the 34 items correlate to the 14 items in the license condition.
4.0 REGULATORY COMMITMENTS The implementing details of the mitigating strategies required by the license condition are identified in licensee submittals dated January 11, 2007 (ADAMS Accession No. ML070160226), and May 8, 2007 (ADAMS Accession No. ML071350258). These details will be implemented by commitment and managed in accordance with the NEI commitment management guideline, NEI 99-04. The NRC staff concludes this provides reasonable controls for mitigating strategy implementation and for subsequent evaluation of licensee-identified changes.
Because the 14 items required by the license condition correlate to the 34 items presented in the February 25, 2005, Phase 1 guidance document and the mitigating strategies within NEIs Phase 2 and 3 proposals, and because the implementing details will be managed under NEI 99-04, the NRC staff is satisfied that there will be sufficient controls to ensure that the strategies are adequately maintained.
5.0 CONCLUSION
Based on the NRC staffs review described in Appendices A, B, and C of this SE, the licensees responses to the February 25, 2005, Phase 1 guidance document and the spent fuel pool and reactor core and containment mitigating strategy assessments meet the requirements of Section B.5.b, Mitigative Measures, of the February 25, 2002, ICM Order that imposed interim compensatory measures on power reactor licensees. The NRC staff concludes that full implementation of the licensees enhancements in the submittals identified in Section 4.0, above, constitutes satisfactory compliance with Section B.5.b and the licensee condition, and represents reasonable measures to enhance the licensees effectiveness in maintaining reactor core and spent fuel pool cooling and containment integrity under circumstances involving the loss of large areas of the plant due to fires or explosions.
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Attachments (Official Use Only - Security-Related Information - ADAMS Accession No. ML071800458):
- 1. Phase 1 Assessment (Appendix A)
- 2. Phases 2 and 3 Assessment (Appendix B)
- 3. Mitigating Strategies Table (Appendix C)
Principal Contributors: David J. Nelson Michael K. Webb Nathan T. Sanfilippo Date: July 11, 2007
Table 1 CROSS REFERENCE BETWEEN LICENSE CONDITION AND GUIDANCE DOCUMENT ELEMENTS License Condition section Guidance Document Elements A. Fire fighting response strategy with the following elements:
- 1. Pre-defined coordinated fire B.1.b Staging of personnel response strategy and guidance B.1.e Outside organization Support B.1.j Treatment of casualties B.1.k Site assembly areas (mass casualties)
B.1.m Industry best practice - feeding fire protection ring header
- 2. Assessment of mutual aid fire B.1.c Airlifted resources fighting assets B.1.f Mobilization of fire fighting resources -
existing or new MOUs B.1.g Mobilization of fire fighting resources -
coordination with other than local mutual aid fire fighting resources (i.e, Industrial facilities, large municipal fire departments, airports, and military bases)
- 3. Designated staging areas for B.1.a Staging of equipment equipment and materials B.1.h Controlling emergency response vehicles (includes rad monitoring)
- 4. Command and Control B.1.d Command and control B.1.i Communications enhancements
- 5. Training of response personnel B.1.l Training considerations
B. Operations to mitigate fuel damage considering the following:
- 1. Protection and use of personnel B.2.a Personnel considerations assets
- 2. Communications B.2.b Communications measures
- 3. Minimizing fire spread B.2.h Compartmentalization of plant areas
- 4. Procedures for implementing B.2.c Procedures (Included in Phase 3 integrated fire response strategy strategies)
B.2.d Evaluation of vulnerable buildings and equipment (Included in Phase 3 strategies)
B.2.e Industry best practice - Containment venting and vessel flooding B.2.f Industry best practice for compensatory function (Included in Phase 3 strategies)
B.2.g Best practice for use of plant equipment B.2.i Best practice involving plant areas potentially affected by fire or explosions (Included in Phase 3 strategies)
B.2.k Best practice for establishing supplemental response capabilities B.2.l Best practice for establishing supplemental response capabilities
- 5. Identification of readily-available, B.2.g Best practice for use of plant pre-staged equipment equipment - portable generator and transformer (Included in Phase 3 strategies)
B.2.j Best practice involving reliance on portable and offsite equipment (Included in Phase 3 strategies)
- 6. Training on integrated fire B.2.n Training considerations response strategy
- 7. Spent fuel pool mitigation B.2.m.1 Dispersal of Fuel measures B.2.m.2 Hot fuel over rack feet B.2.m.3 Downcomer area B.2.m.4 Enhanced air circulation (Included in Phase 2 strategies)
B.2.m.5 Emergency pool makeup, leak reduction/repair (Included in Phase 2 strategies)
C. Actions to minimize release to include considerations of:
- 1. Water spray scrubbing B.3.a Water spray scrubbing B.3.b Prestaging of equipment
- 2. Dose to onsite responders B.3.c Dose projection models (Included in Phase 3 strategies)
Diablo Canyon Power Plant, Units 1 and 2 cc:
NRC Resident Inspector Jennifer Post, Esq.
Diablo Canyon Power Plant Pacific Gas & Electric Company c/o U.S. Nuclear Regulatory Commission P.O. Box 7442 P.O. Box 369 San Francisco, CA 94120 Avila Beach, CA 93424 City Editor Sierra Club San Lucia Chapter The Tribune ATTN: Andrew Christie 3825 South Higuera Street P.O. Box 15755 P.O. Box 112 San Luis Obispo, CA 93406 San Luis, Obispo, CA 94306-0112 Ms. Nancy Culver Director, Radiologic Health Branch San Luis Obispo State Department of Health Services Mothers for Peace P.O. Box 997414, MS 7610 P.O. Box 164 Sacramento, CA 95899-7414 Pismo Beach, CA 93448 Mr. James Boyd, Commissioner Chairman California Energy Commission San Luis Obispo County 1516 Ninth Street MS (31)
Board of Supervisors Sacramento, CA 95831 1055 Monterey Street, Suite D430 San Luis Obispo, CA 93408 Mr. James R. Becker, Vice President Diablo Canyon Operations and Mr. Truman Burns Station Director Mr. Robert Kinosian Diablo Canyon Power Plant California Public Utilities Commission P.O. Box 56 505 Van Ness, Room 4102 Avila Beach, CA 93424 San Francisco, CA 94102 Jennifer Tang Diablo Canyon Independent Safety Field Representative Committee United States Senator Barbara Boxer Attn: Robert R. Wellington, Esq. 1700 Montgomery Street, Suite 240 Legal Counsel San Francisco, CA 94111 857 Cass Street, Suite D Monterey, CA 93940 Regional Adminstrator, Region IV U.S. Nuclear Regulatory Commission Harris Tower & Pavillion 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 June 2007