ML19114A490
| ML19114A490 | |
| Person / Time | |
|---|---|
| Issue date: | 04/25/2019 |
| From: | Alexander Schwab NRC/NRR/DRA/APOB |
| To: | Antonios Zoulis NRC/NRR/DRA/APOB |
| References | |
| Download: ML19114A490 (3) | |
Text
Risk Informed Steering Committee NRC Activity Status 1
Activity Current Status 50.69 Issue: NRC informed industry last year that resources were available for 10 reviews/year for completion within 12 months of acceptance. Nineteen 50.69 LARs have been submitted since issuance of the pilot). After the first 10 were submitted, NRC starting planning for 15 month review schedules for the subsequent submittals. NRC issued the SE for approval of the first non-pilot 50.69 LAR (Limerick) in 11 months from the date of acceptance (one month ahead of the 12 month review schedule). NRC also issued approval of the seismic PRA for the Vogtle 50.69 pilot plant, which was originally approved using the seismic margins safe shutdown list instead of a seismic PRA. NRC has completed its review of 6 50.69 LARs (considering Byron and Braidwood as 1 LAR) and 3 more were withdrawn. NRC currently has 10 LARs under review and anticipates at least 5 additional submittals in by the end of the calendar year. With many reviews completed and others nearing completion, NRC is now scheduling new 50.69 submittals on a 12 month schedule. The use of the seismic alternative for 50.69 for one of the two lead plants is currently under review. The schedule for this lead plant extends past one-year. A second lead plant for a seismic alternative is expected later this calendar year.
Next Steps:
NRC: Staff has shifted to virtual audits for 50.69 reviews, which has resulted in increased resource efficiency. Staff has recently identified instances where the licensees method of identifying key assumptions and sources of uncertainty resulted in a deviation from the guidance of NEI 00-04 and NUREG-1855. Path forward is being addressed with the licensee. LARs which 1) follow the industry template and 2) have technically acceptable PRAs (i.e., necessary peer reviews completed with F&Os adequately dispositioned) require less time and resources for NRC to review. NRC and Industry conducted a 50.69/4b lessons-learned workshop January 30-31.
TSTF - 505 Issue: Staff approved TSTF-505, Revision 2, November 2018. Revision 2 excludes loss of safety function for RICTs. The first two LARs referenced the revised TSTF were submitted on December 13, 2018. The staff is in the process of completing its acceptance review.
Regarding plant-specific 4b reviews, the staff issued the SE for Calvert Cliffs on October 30, 2018, and the Turkey Point SE on December 3, 2018. Staff is actively working to complete the reviews of St. Lucie and Palo Verde LARs by early 2019. On July 27, 2018, Farley submitted a LAR that did not reference the TSTF-505 travel but, instead, is consistent with the guidelines of NEI 06-09, Risk-Informed Technical Specifications Initiative 4b, Risk-Managed Technical Specifications (RMTS) Guidelines. The NRC staff accepted the LAR for review on August 31, 2018, with a scheduled completion date of August 2019.
Next Steps: NRC and Industry conducted a 50.69/4b lessons-learned workshop January 30-31. The workshop included a discussion on risk-informed licensing amendment workload forecasting for more effective resource planning. The staff expects to receive at least 10 additional LARs this calendar year.
Risk Informed Steering Committee NRC Activity Status 2
New Methods Issue: For risk-informed LARs, the NRC determines the acceptability of a licensees PRA using peer-reviews. As a result of staff observations during the review of LARs relating to NFPA 805, the staff became concerned about the adequacy of these process, especially relating to new methods. Staff believes that the regulatory framework (e.g., Reg Guide 1.200) must be updated to accommodate lessons learned from Fire PRA and other recent LAR reviews to maintain due reliance on the peer-reviews as they pertain to new PRA methods. In 2015, the Nuclear Energy Institute (NEI) had proposed a vetting panel process to address this issue (NEI 16-04). In January 2018, NEI provided an alternative proposal, which was revised and presented formally at a public meeting in June 2018. Also in June NEI requested that the staff stop its review of NEI 16-04. NRC held three public meetings (June 18, 2018, September 6, 2018, and November 14, 2018) and participated in two Owners Group meetings to work on activities related to NEIs new proposal. During the meeting on November 14, industry representatives affirmed that they agree with NRCs path forward and requested that we expedite completion of tasks essential to enable implementation of NEIs alternative.
Next Steps:
NRC: There are three tasks that must be completed: a) issuing a letter endorsing NEI 17-07 with necessary classification, b) documenting components that would normally reside in ASME\\ANS Standard (e.g., definition of PRA Upgrade, Newly Developed Method) in a formal document pending publication of ASME\\ANS Standard and Rev. 3 of RG 1.200, and c) creating or enhancing processes procedures to implement NEIs alternative. For each of the three tasks, in December 2018, NRC and industry aligned on three project plans. All three tasks are on schedule. We have a draft NEI 17-07 and a draft review criteria and definitions that staff and industry has aligned on. The next step is to pilot them and modify them to incorporate insights from pilots. Staff has also received an administrative tech spec to execute the industry proposal on newly-developed methods. Staff is in the process of evaluating that proposal. Barring any unanticipated significant changes to resolution of issues or events that requires significant PRA resources, NRC is making plans to complete these three activities in FY 2019 with the exception of updating the inspection procedures\\ROP frame work.
Fire PRA Realism Issue: Industry has indicated that an improvement in fire PRA realism is necessary to support risk informed regulatory applications.
The staff is supporting this effort, despite its ability to make risk informed decisions with the current level of realism as proven by the NFPA 805 program.
Next Steps:
NRC: Ongoing public meetings (quarterly) review and update FAQs. Four (4) remain to be reviewed/resolved. Public workshop scheduled in April, 2018 to address unresolved FAQs. RES/NRR observed VEWFDS expert elicitation week of Nov. 12th, 2018.
RES/EPRI engagement ongoing.
NRC and Industry: Continue to work towards resolution of remaining draft fire PRA FAQs.
Flex in RIDM Issue: Licensees have requested credit for FLEX strategies in a number of areas beyond their original purpose (BDBEE) (e.g. SDP, LARs, NOEDs). NRC staff and licensees are conducting several activities to enable licensees to appropriately credit FLEX. There are several challenges that may require NRC & Industry RISC engagement.
Risk Informed Steering Committee NRC Activity Status 3
Next Steps:
NRC: (NRR/DRA&RES/DRA): Finalize draft report on Expert Elicitation that will be made publicly available (1st Qtr, 2019).
Industry: Sharing FLEX operational experience data with NRC staff. (1st Qtr. 2019)
TMRE Issue: Develop and demonstrate implementation of a risk informed tornado missile protection evaluation model for licensees with non-compliant legacy design SSCs. NEI 17-02 Revision 1 drafted for use by pilot plants Next Steps:
NRC: The Vogtle TMRE SE was issued on January 11. The Harris and Grand Gulf pilot LAR SEs are in final review, with Harris SE issuance expected before a forthcoming public meeting on post-pilot TMRE applications (currently scheduled for March 15). The Grand Gulf SE is expected to serve as the template SE for future TMRE LARs.
The March public meeting intends to discuss an NRR Office Director letter on tornado missile protection..