SECY-06-0196, G20060987 - Marvin S. Fertel Ltr. NRC-SECY-06-0196 - Issuance of Generic Letter 2006-XX, Post-Fire Safe Shutdown Circuit Analysis, September 11, 2006
| ML070300642 | |
| Person / Time | |
|---|---|
| Issue date: | 02/20/2007 |
| From: | Reyes L NRC/EDO |
| To: | Fertel M Nuclear Energy Institute |
| Klein A, NRR/DRA, 415-3477 | |
| Shared Package | |
| ML070310097 | List: |
| References | |
| G20060987, GL-06-000, SECY-06-0196, TAC MD4257 | |
| Download: ML070300642 (5) | |
Text
February 20, 2007 Mr. Marvin S. Fertel, Senior Vice President and Chief Nuclear Officer Nuclear Energy Institute 1776 I Street, NW., Suite 400 Washington, DC 20006
Dear Mr. Fertel:
Thank you for your letter dated October 13, 2006, and reissued on December 4, 2006, commenting on SECY-06-0196, Issuance of Generic Letter 2006-XX, Post-Fire Safe-Shutdown Circuit Analysis Spurious Actuations.
As you are aware, the Commission disapproved the issuance of the draft generic letter in staff requirements memorandum (SRM) SECY-06-0196, Staff Requirements SECY-06-0196 Issuance of Generic Letter 2006-XX, Post-Fire Safe-Shutdown Circuits Analysis Spurious Actuations, dated December 15, 2006 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML063490140).
As directed in the SRM, the staff plans to develop or endorse guidelines that clearly define a method to address circuit analysis. Stakeholder involvement will be assured through our normal public regulatory process in developing the guidelines. As a first step, the staff held a public meeting with stakeholders on February 16, 2007, to initiate stakeholder engagement and solicit input to our closure plan.
Please refer to the enclosure for our response to the key issues you raised in your letter.
Sincerely,
/RA/
Luis A. Reyes Executive Director for Operations
Enclosure:
As stated
February 20, 2007 Mr. Marvin S. Fertel, Senior Vice President and Chief Nuclear Officer Nuclear Energy Institute 1776 I Street, NW., Suite 400 Washington, DC 20006
Dear Mr. Fertel:
Thank you for your letter dated October 13, 2006, and reissued on December 4, 2006, commenting on SECY-06-0196, Issuance of Generic Letter 2006-XX, Post-Fire Safe-Shutdown Circuit Analysis Spurious Actuations.
As you are aware, the Commission disapproved the issuance of the draft generic letter in staff requirements memorandum (SRM) SECY-06-0196, Staff Requirements SECY-06-0196 Issuance of Generic Letter 2006-XX, Post-Fire Safe-Shutdown Circuits Analysis Spurious Actuations, dated December 15, 2006 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML063490140).
As directed in the SRM, the staff plans to develop or endorse guidelines that clearly define a method to address circuit analysis. Stakeholder involvement will be assured through our normal public regulatory process in developing the guidelines. As a first step, the staff held a public meeting with stakeholders on February 16, 2007, to initiate stakeholder engagement and solicit input to our closure plan.
Please refer to the enclosure for our response to the key issues you raised in your letter.
Sincerely,
/RA/
Luis A. Reyes Executive Director for Operations
Enclosure:
As stated DISTRIBUTION: G20060987 DRA r/f RidsNrrWpcnMail RidsEdoMailCenter RidsOgcMailCenter E.Baker RidsOeMailCenter Adams Accession No. (Package) ML070310097 Adams Accession No. (Incoming) ML063400405 Adams Accession No. (EDO-002Response) ML070300642 EDO-002 OFFICE NRR/DRA/AFPB NRR/DRA/AFPB NRR/DRA Tech Editor D:NRR EDO NAME AKlein SWeerakkody CHolden HChang JDyer LReyes via e-mail /RA J. Grobe/
DATE 01/ 30 /07 01/ 30 /07 02/ 06 /07 02/ 06 /07 02/ 15 /07 02/ 20 /07 OFFICIAL RECORD COPY
U.S. Nuclear Regulatory Commission Response to Nuclear Energy Institute Letter October 13, 2006 (Reissued December 4, 2006)
I. NRC Staffs Backfit Evaluation NEI Comment NEI states that the fundamental issue is whether the U.S. Regulatory Commission (NRC) position with respect to the one at a time direction is a new staff position. NEI contends that this staff position has been applied differently at other plants and no clear direction exists in regulations or guidance. NEI also contends that the staffs selection of one of several interpretations does not in itself justify the now-preferred staff position into law and does not allow a claim that the compliance exception to the backfit rule should apply.
Staff Response The Commissions staff requirements memorandum (SRM) stated that the staff has not made a compelling case for its backfit position in draft Generic Letter (GL) 2006-XX. The staff plans to address its backfit position when it responds to the Commissions direction in the SRM. As directed in the SRM, the staff will engage stakeholders to develop or endorse guidelines.
II. Interpretation of the Industry Cable Fire Test Results NEI Comment NEI quotes a statement from SECY 06-0196, the staff and NEI concluded that the probability of fire-induced circuit failures can be relatively high and that there can be a relatively high probability of multiple spurious actuations occurring simultaneously or in rapid succession.
NEI states that the reference to NEI in that statement is inaccurate and contends that a careful review of all the observations and conclusions of the Electric Power Research Institute (EPRI)/NEI tests (EPRI Technical Report 1003326, Characterization of Fire-Induced Cable Faults: Results of Cable Fire Testing) will lead to a different overall conclusion that is currently proposed by the staff.
Staff Response NEI is correct that the EPRI/NEI test report does not include a conclusion by NEI as stated in SECY 06-0196.
However, the staff concludes that the probability of fire-induced circuit failures can be relatively high and that there can be a relatively high probability of multiple spurious actuations occurring simultaneously or in rapid succession. The staffs conclusion is based on the Key Observations and Conclusions section of EPRI Technical Report 1003326 that states, Given that a hot short occurs in a multi-conductor cable, it is highly probable (over 80%) that multiple target conductors will be affected (i.e., multiple simultaneous dependent hot shorts).
III. CAROLFIRE Program NEI Comment NEI requested an opportunity to peer review the test results from the NRCs CAROLFIRE testing program.
ENCLOSURE
2 Staff Response The CAROLFIRE test results will be made public as soon as they are available. The staff intends to engage stakeholders during the development of the regulatory application of the test results. The staff will use the normal public regulatory process to engage stakeholders. NRC will not seek peer reviews from external stakeholder for the CAROLFIRE test results. Prior to conducting the tests, the CAROLFIRE test plan was peer reviewed by a number of individuals and organizations, including an electrical engineering expert in fire-induced circuit failures and the University of Maryland.
IV. Implementing Costs NEI Comment NEI stated that the staff underestimated the costs for implementing the draft GL. The staff did not account for plant modifications. NEI stated that the draft GL could cost the industry
$200 - $500 million dollars, not including the cost of potential plant modifications. NEI believes that there is a high degree of uncertainty with the staffs estimate because of the nonspecific and unbounded circuit failure requirements in the draft GL.
Staff Response The staff will follow the Commission direction to engage stakeholders to develop or endorse guidelines that provide a clearly defined method to address this issue. This effort should reduce the uncertainty in the cost estimates. We welcome any specific information you can supply during our stakeholder interactions.
V. EPRI/NEI Test Results NEI Comment NEI commented that the EPRI/NEI tests (EPRI Technical Report 1003326) did not yield test results that are drastically different from the existing knowledge base prior to testing. NEI provided four examples from the fire tests as a basis for their comment.
Staff Response The staff disagrees with NEIs comments that the EPRI/NEI tests did not yield results that drastically differed from existing knowledge prior to testing. The staff believes that the test results significantly advanced the knowledge base beyond that used to develop industry guidance on circuit analysis (NEI 00-01, Guidance for Post-Fire Safe Shutdown Circuit Analysis), and improved risk-informed NRC inspection guidance (RIS 2004-03, Rev. 1, Risk-Informed Approach for Post-Fire Safe-Shutdown Circuit Inspections). The EPRI/NEI tests also provided additional information on the likelihood of cable failures that would warrant further NRC action. Although the Commission disapproved issuing the draft GL 2006-XX in its present form, the Commission recognized the importance of the test results and the need to address this issue. The Commission directed the staff to ensure that the resolution of this licensing issue has a technically sound and traceable regulatory footprint that will provide permanent closure to this issue.
3 VI. Increased Scope of Draft GL 2006-XX by Including Paragraph III.G.3 of Appendix R of 10 CFR Part 50 NEI Comment NEI commented that the applicability of paragraph III.G.3 (from Appendix R of 10 CFR Part 50) in draft Generic Letter 2006-XX is a significant scope change occurring after the public comment period for the proposed GL. NEI commented that the staff needs to clearly identify the parameters for paragraph III.G.3.
Staff Response The proposed GL, issued in October 2005 for public comment, took excerpts from General Design Criterion 3, Title 10 of the Code of Federal Regulations (10 CFR 50.48(a)), and paragraphs III.G.1 and III.G.2 of Appendix R of 10 CFR Part 50. The proposed GL did not specifically reference paragraph III.G.3. However, paragraph III.G.2 references paragraph III.G.3 in its opening sentence, Except as provided for in paragraph G.3 of this section.... The regulations clearly indicate the applicability and relevance of paragraph III.G.3 when determining compliance with paragraph III.G.2.
In the draft GL, the staff requested information on protecting redundant safe shutdown trains from multiple simultaneous spurious actions and maintaining one train free of damage as addressed in paragraphs III.G.2 and III.G.3.
As directed in the SRM, the staff will engage stakeholders to develop or endorse guidelines that provide a clearly defined method to address this issue.