ML24026A110
| ML24026A110 | |
| Person / Time | |
|---|---|
| Issue date: | 01/24/2024 |
| From: | David Rudland NRC/NRR/DNRL/NPHP |
| To: | |
| References | |
| Download: ML24026A110 (1) | |
Text
Recent International Operational Experience & Regulatory Actions David L. Rudland Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission NDE Technical Information Exchange Meeting January 23-25, 2024
Carbon Macro Segregation - Issue Directional Conventional Pouring of an Ingot Forging Ingot Shift in RTNDT Final Part ASME Carbon ~0.25%
Local measured ~0.25%-0.35%
2
Carbon Macro Segregation - Timeline 2016 AREVA notified ASN 2015 EDF found irregularities when of over 400 parts April 2017 NRC testing Flamanville manufactured since 1965 investigates allegation of head - some were sent to US records falsification December 2016 ASN/MDEP 2016 NRC 2017 ASN orders found irregularities in Creusot conducts EDF to review all preliminary Creusot Forge Forge Audit - possible safety falsification of document documentation assessment Jan 2017 All forgings produced by Creusot May 2017 NRC Forge for U.S. plants conducts a vendor June 2017 EPRI evaluation of the identified - 17 units inspection of Areva risk posed by CMAC in large identified Creusot Forge nuclear forging issued Jan 2017 2.206 June 2017 ASN/IRSN Feb 2018 NRC staff petition filed by releases report a fast final assessment Beyond Nuclear fracture analysis of released CMAC 3
Carbon Macro Segregation - NRC Response
- International bi-lateral discussions
- Addressing records anomaly through audit and review
- Addressing potential Part 21 and 10 CFR 2.206
- Addressing Management, Commission and Congressional concerns
- Developing preliminary and final safety assessment through use of LIC-504
- Safety impact was negligible (ML18017A441)
- Regional support 4
CRDM Thermal Sleeve Wear - Issue 5
CRDM Thermal Sleeve - Timeline May 2018 April 2018 - Letter Westinghouse Dec 2017 - Stuck MRP 2018-10 submits notification Control Rod - Notification of CRDM of potential defect Belleville-sur-Loire 2 thermal sleeve wear Part 21 Feb 2018 - EDF May 2018 Wolf May 2018 ASN declared to the ASN Creek finds 9 reports another a significant safety locations of plant experiences a event. lowered sleeve stuck rod January 2019 NRC July 2018 Westinghouse August 2018 NEI releases NEI- releases report on Smart issues NSAL18-1 Rev. 0 03-08 Needed guidance sample August 2018 NRC releases November IN 18-10 and LIC-504 2018 NRC analysis recommending a releases Smart smart sample sample plan 6
CRDM Thermal Sleeve - NRC Response
- International bi-lateral discussions at first indication of OE
- Addressing Management, and Commission concerns
- Developing preliminary and final safety assessment through use of LIC-504 (ML18249A081)
- Regional support and coordination through smart sample
- Smart sample data analyses and report generation (ML19035A503) 7
Framatome PWHT- Issue
- After welding, local post weld heat treatment was performed using ceramic heaters
- Per a change in French regulation, Framatome conducted analyses during a program to optimize the process and found PWHT temperature not maintained over whole area - verified by Mock-ups
- Issue was with the serpentine heaters
- Part 21 was opened and impacted components identified including several replacement US components
- Issue resulted in PWHT at temps <50C from ASME limit but soak times were 7 US plants were supplied with sufficient components with this issue 8
Framatome PWHT- Timeline September 2019, Jan 2021 Framatome January 2020, Framatome identified a Framatome reports to NRC deviation in the identified that a third PWHT of certain another issue components deviation in pertaining to manufactured the PWHT ID welds was after 2008 process discovered October 2019 May 2020 March 2021 Framatome Framatome Framatome analyses suggest reports reports third issue not analyses issue is not reportable via suggest issue reportable Part 21 not reportable via Part 21 9
Framatome PWHT- NRC Response
- International bi-lateral discussions
- Reviewing Part 21 analyses meeting with Framatome
- Determination of immediate safety assessment - qualitative
- Regional support including end of cycle meeting support 10
French SCC- Issue Safety injection system Most flaws found were very shallow and long Expanded inspection found over 100 flaws some up to 85% deep Root cause was attribute to thermal stratification and welding stress 11
French SCC- Timeline Jan 2022 flaw March 2022 removed from EPRI/PWROG Oct 2021 Flaws Civaux were kicked off Focus found at Civaux 1 IGSCC group Nov 2021 more flaws March 2022 ASN expanded March 2023, 85%
found at Civaux 2 and inspection to all ECCS/RHR deep flaw found Penly 1 systems at Penly 1 - near hot leg March 2023 NRC April 2024 PWROG conducts qualitative July 2023 NRC begins publishes applicability BeRiskSMART analysis LIC-503 effort report April 2023 PWROG September 2023 NRC publishes PWROG- finalizes LIC-504 23007-NP, Revision 0 12
French SCC- Response
- International bi-lateral discussions with France, Japan, Spain, UK
- Participated in Western European Nuclear Regulators Association (WERNA) to develop report and recommendation
- Addressing Management, and Commission concerns
- Determination of immediate safety assessment - qualitative (BeRiskSMART) and quantitative (LIC-504 ML23236A052)
- Regional support
- Several public meetings including Feb 21, 2024 13
THANK YOU 14