|
|
Line 15: |
Line 15: |
|
| |
|
| =Text= | | =Text= |
| {{#Wiki_filter:}} | | {{#Wiki_filter:Question 1: Why did you remove multiple coupons from Unit 2 but only one, in 2002, from Unit 1? |
| | Answer: Thanks for the opportunity to clarify. For Diablo Canyon Unit 1, to date, the licensee has withdrawn seven coupons and tested three of them (the other four are stored for future use if needed). The most recent test was completed in 2002, as previously discussed. Additionally, the previously referenced NRC safety evaluation (ML120330497) dated March 2, 2012, discusses the successful completion of all three rounds of neutron embrittlement coupon testing that were required under 10CFR50 Appendix H for Unit 1 through the end of its operating license. For comparison, six coupons were withdrawn from Unit 2, four of which were tested in accordance with the 10CFR50 Appendix H testing requirements for that unit. |
| | Question 2: I appreciate the answers you sent about Palisades; they clarify some of my questions about Diablo Canyon. But these were submitted 9 years ago. I would assume that the NRC has done much more work on embrittlement since 2013. Is that correct? |
| | Answer: Yes, the NRC has continued to monitor and review neutron embrittlement testing conducted in accordance with 10CFR50 Appendix H, at other nuclear plants across the country. There is no new information since the 2012/2013 timeframe that changes our assessment that the Unit 1 and 2 pressure vessels will maintain their integrity through the end of the Diablo Canyon operating licenses without any additional coupon testing needed. We continue to have confidence that both plants can be operated safely through 2024 and 2025. |
| | The NRC continues its efforts associated with reactor pressure vessel integrity and embrittlement and a summary of those efforts can be found in NUREG-1925, Research Activities, Revision 4. Furthermore, the NRC held a workshop in 2019 with one of the focus areas on reactor pressure vessel embrittlement at high fluence levels. The NRC presentations during this workshop can be found in RIL 2020-12, International Workshop on Age-Related Degradation of Reactor Vessels and Internals. |
| | More recently, the NRC issued SECY-22-0019: Rulemaking Plan for Revision of Embrittlement and Surveillance Requirements for High-Fluence Plants in Long-Term Operation in 2022. This document provides additional references to the NRCs effort associated with reactor pressure vessel embrittlement. The focus of this SECY paper is on nuclear power plants that decide to pursue long-term operation and exceed a neutron fluence for the reactor pressure vessel of 6x1019 n/cm2. In comparison, the projected neutron fluence for reactor pressure vessels at Diablo Canyon Unit 1 and 2 after 40-years of operation are approximately 1.26x1019 n/cm2 and 1.40x1019 n/cm2, respectively.}} |
Latest revision as of 09:13, 29 June 2022
|
---|
Category:- No Document Type Applies
MONTHYEARML22278A2962022-10-0505 October 2022 FAQ 22-02- Diablo Canyon Scram - Final Approved ML22276A2402022-10-0303 October 2022 1) FAQ Response Provided by NEI ML22179A0302022-06-22022 June 2022 Plants 1 and 2 - Response to Public Questions Regarding Unit 1 Reactor Vessel Neutron Embrittlement Coupon Testing - June 28, 2022 ML22166A4442022-06-15015 June 2022 Plants 1 and 2 - Response to Public Questions Regarding Unit 1 Reactor Vessel Neutron Embrittlement Coupon Testing - June 15, 2022 ML22206A2602022-05-23023 May 2022 FAQ 22-02- Diablo Canyon Scram - Proposed ML22144A1442022-05-23023 May 2022 FAQ 22-02 - Diablo Canyon Scram ML21060B1842021-03-0101 March 2021 Enclosure 1 - 1-26-21 Diablo Canyon Renewal pre-app Meeting Attendee List ML20141L7102020-05-14014 May 2020 NRC-2019-000279 - Resp 4 - Interim, Agency Records Subject to the Request Are Enclosed. (Released Set of 2014-0488 3, Part 2 of 2) ML20141L7092020-05-14014 May 2020 NRC-2019-000279 - Resp 4 - Interim, Agency Records Subject to the Request Are Enclosed. (Released Set of 2014-0488 3, Part 1 of 2) ML20141L7142020-05-14014 May 2020 NRC-2019-000279 - Resp 4 - Interim, Agency Records Subject to the Request Are Enclosed. (Released Set of 2014-0488 5, Part 2 of 2) ML20141L7152020-05-14014 May 2020 NRC-2019-000279 - Resp 4 - Interim, Agency Records Subject to the Request Are Enclosed. (Released Set of 2014-0488, Parts 1 and 2) ML20141L7162020-05-14014 May 2020 NRC-2019-000279 - Resp 4 - Interim, Agency Records Subject to the Request Are Enclosed. (Released Set of 2015-0071, Part 1 of 2) ML20141L7132020-05-14014 May 2020 NRC-2019-000279 - Resp 4 - Interim, Agency Records Subject to the Request Are Enclosed. (Released Set of 2014-0488 5, Part 1 of 2) ML20141L7122020-05-14014 May 2020 NRC-2019-000279 - Resp 4 - Interim, Agency Records Subject to the Request Are Enclosed. (Released Set of 2014-0488 4, Part 2 of 2) ML20141L7112020-05-14014 May 2020 NRC-2019-000279 - Resp 4 - Interim, Agency Records Subject to the Request Are Enclosed. (Released Set of 2014-0488 4, Part 1 of 2) ML20141L7172020-05-14014 May 2020 NRC-2019-000279 - Resp 4 - Interim, Agency Records Subject to the Request Are Enclosed. (Released Set of 2015-0071, Part 2 of 2) ML20141L7182020-05-14014 May 2020 NRC-2019-000279 - Resp 4 - Interim, Agency Records Subject to the Request Are Enclosed. Released Set of New OE Docs (for NRC-2019-000279 Item 2) ML20262G9682020-03-19019 March 2020 Health Order 3.19.2020 ML16314A9642016-11-0909 November 2016 Summary of Hydrodynamic Effect in Spent Fuel Pool Auxiliary Building ML16314A9732016-11-0909 November 2016 Pacific Gas and Electric Company Checking Columns in Auxiliary Building Unit 1 for 7.5M Hosgri Vertical Acceleration ML16314D3162016-11-0909 November 2016 Comment Sheets ML16285A3232016-10-12012 October 2016 ROP PI Frequently Asked Questions (Faqs): 13-07 ML16179A2192016-06-27027 June 2016 LTR-16-0333-1 - Oedo Ticket - Edward D. Halpin, Senior Vice President, Generation and Chief Nuclear Officer, Pacific Gas and Electric Company, Letter Request to Suspend NRC Review of Diablo Canyon Power Plant License Renewal Application ML16084A6102016-03-30030 March 2016 MSFHI Tables 1&2 Final 3-24-2016 ML16054A0092016-02-12012 February 2016 FOIA/PA-2015-0294 - Resp 2 - Final, Agency Records Subject to the Request Are Enclosed. Part 8 of 8 ML16054A0072016-02-12012 February 2016 FOIA/PA-2015-0294 - Resp 2 - Final, Final Response #2, Records Already Publicly Available ML16054A0112016-02-12012 February 2016 FOIA/PA-2015-0294 - Resp 2 - Final, Agency Records Subject to the Request Are Enclosed. Part 3 of 8 ML16054A0142016-02-12012 February 2016 FOIA/PA-2015-0294 - Resp 2 - Final, Agency Records Subject to the Request Are Enclosed. Part 6 of 8 ML16054A0082016-02-12012 February 2016 FOIA/PA-2015-0294 - Resp 2 - Final, Agency Records Subject to the Request Are Enclosed. Part 1 of 8 ML16054A0152016-02-12012 February 2016 FOIA/PA-2015-0294 - Resp 2 - Final, Agency Records Subject to the Request Are Enclosed. Part 7 of 8 ML16054A0102016-02-12012 February 2016 FOIA/PA-2015-0294 - Resp 2 - Final, Agency Records Subject to the Request Are Enclosed. Part 2 of 8 ML16054A0122016-02-12012 February 2016 FOIA/PA-2015-0294 - Resp 2 - Final, Agency Records Subject to the Request Are Enclosed. Part 4 of 8 ML16054A0132016-02-12012 February 2016 FOIA/PA-2015-0294 - Resp 2 - Final, Agency Records Subject to the Request Are Enclosed. Part 5 of 8 ML15344A4322016-01-12012 January 2016 DCPP Section 106 Checklist ML15237A3352015-08-21021 August 2015 Attachment 3 - A.15-02-023 Supplemental Testimony of John Geesman ML15237A3342015-07-14014 July 2015 Attachment 1 - A.15-02-023 Prepared Testimony of John Geesman ML15237A3232015-07-14014 July 2015 Attachment 2 - A.15-02-023 Prepared Testimony of Sam Blakeslee ML15070A6082015-03-11011 March 2015 Response to NRC Request for Info. Pursuant to 10 CFR 50.54(f) Seismic Aspects of Recommendation 2.1 of Near-Term Task Force Review of Insights from Fukushima Dai-ichi Accident: Seismic Hazard Screening Report. Part 2 of 2 DCL-15-034, Final Response to Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.1 Flooding. Part 2 of 22015-03-11011 March 2015 Final Response to Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.1 Flooding. Part 2 of 2 ML15014A1602015-01-14014 January 2015 Attachment 2 - NRC Working Group Recommendations to Revise the Substantive Cross-Cutting Issue Process ML15014A1532015-01-14014 January 2015 Attachment 1- NEI Comments on NRC Working Group Recommendations to Revise the Substantive Cross-Cutting Issue Process ML14349A3872014-12-11011 December 2014 FOIA/PA-2014-0059 - Resp 2 - Final. Group C (Records Being Released in Part) ML14302A8062014-10-29029 October 2014 Enclosure - Ninety-Day Response to NRC Request for Additional Information - National Fire Protection Association Standard 805 ML13130A2282013-05-10010 May 2013 Safety Injection Issue Summary Pump 2-1 Issue Information DCL-13-021, Performance Demonstration Initiative (POI) Program Alternatives and Their Bases with Respect to ASME Code Section Xi, Appendix Viii Supplement 11 Requirements2013-03-0505 March 2013 Performance Demonstration Initiative (POI) Program Alternatives and Their Bases with Respect to ASME Code Section Xi, Appendix Viii Supplement 11 Requirements ML13078A2972013-03-0505 March 2013 Enclosure 1, Inservice Inspection (ISI) Relief Request REP-1 U2, Revision 2 in Accordance with 10 CFR 50.55a(a)(3)(i) ML13078A2932013-03-0505 March 2013 Performance Demonstration Initiative (POI) Program Alternatives and Their Bases with Respect to ASME Code Section Xi, Appendix Viii Supplement 11 Requirements DCL-12-119, Response to Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.3 Seismic Unit 2, Part 2 of 32012-11-27027 November 2012 Response to Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.3 Seismic Unit 2, Part 2 of 3 ML12333A2692012-11-27027 November 2012 Response to Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.3 Seismic Unit 2, Part 3 of 3 ML12333A2662012-11-27027 November 2012 Response to Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.3 Seismic Unit 1. Part 2 of 2 2022-06-22
[Table view] |
Text
Question 1: Why did you remove multiple coupons from Unit 2 but only one, in 2002, from Unit 1?
Answer: Thanks for the opportunity to clarify. For Diablo Canyon Unit 1, to date, the licensee has withdrawn seven coupons and tested three of them (the other four are stored for future use if needed). The most recent test was completed in 2002, as previously discussed. Additionally, the previously referenced NRC safety evaluation (ML120330497) dated March 2, 2012, discusses the successful completion of all three rounds of neutron embrittlement coupon testing that were required under 10CFR50 Appendix H for Unit 1 through the end of its operating license. For comparison, six coupons were withdrawn from Unit 2, four of which were tested in accordance with the 10CFR50 Appendix H testing requirements for that unit.
Question 2: I appreciate the answers you sent about Palisades; they clarify some of my questions about Diablo Canyon. But these were submitted 9 years ago. I would assume that the NRC has done much more work on embrittlement since 2013. Is that correct?
Answer: Yes, the NRC has continued to monitor and review neutron embrittlement testing conducted in accordance with 10CFR50 Appendix H, at other nuclear plants across the country. There is no new information since the 2012/2013 timeframe that changes our assessment that the Unit 1 and 2 pressure vessels will maintain their integrity through the end of the Diablo Canyon operating licenses without any additional coupon testing needed. We continue to have confidence that both plants can be operated safely through 2024 and 2025.
The NRC continues its efforts associated with reactor pressure vessel integrity and embrittlement and a summary of those efforts can be found in NUREG-1925, Research Activities, Revision 4. Furthermore, the NRC held a workshop in 2019 with one of the focus areas on reactor pressure vessel embrittlement at high fluence levels. The NRC presentations during this workshop can be found in RIL 2020-12, International Workshop on Age-Related Degradation of Reactor Vessels and Internals.
More recently, the NRC issued SECY-22-0019: Rulemaking Plan for Revision of Embrittlement and Surveillance Requirements for High-Fluence Plants in Long-Term Operation in 2022. This document provides additional references to the NRCs effort associated with reactor pressure vessel embrittlement. The focus of this SECY paper is on nuclear power plants that decide to pursue long-term operation and exceed a neutron fluence for the reactor pressure vessel of 6x1019 n/cm2. In comparison, the projected neutron fluence for reactor pressure vessels at Diablo Canyon Unit 1 and 2 after 40-years of operation are approximately 1.26x1019 n/cm2 and 1.40x1019 n/cm2, respectively.