ML19225D281
| ML19225D281 | |
| Person / Time | |
|---|---|
| Issue date: | 08/15/2019 |
| From: | Sandra Walker Division of Inspection and Regional Support |
| To: | Ho Nieh Office of Nuclear Reactor Regulation |
| References | |
| SRM-M190620 | |
| Download: ML19225D281 (6) | |
Text
August 15, 2019 MEMORANDUM TO:
Ho Nieh, Director Office of Nuclear Reactor Regulation FROM:
Shakur Walker, Acting Deputy Director /RA/
Division of Inspection and Regional Support Office of Nuclear Reactor Regulation
SUBJECT:
ANALYSIS OF INSPECTION FINDINGS TREND AT NUCLEAR POWER REACTORS BETWEEN 2015 AND 2018 This memo provides the staffs response to Staff Requirements Memorandum (SRM) SRM-M190620, Staff Requirements - Briefing on Results of the Agency Action Review Meeting, dated June 26, 2019 (Agencywide Documents Access and Management System (ADAMS)
Accession No. ML19178A030).
Summary The staff briefed the Commission on the results of the Agency Action Review Meeting on June 20, 2019. During the briefing, the Commission and staff discussed a decline in the number of inspection findings issued under the Reactor Oversight Process (ROP) over the last several years. Specifically, between 2015 and 2018, the number of inspection findings dropped from 816 to 476, a 42 percent reduction. During this time, there were no appreciable changes to the scope or size of the U.S. Nuclear Regulatory Commission (NRCs) baseline inspection program.
The resulting SRM, SRM-M190620, directed the staff to perform an analysis to better understand the likely causes of the decline in the number of power reactor inspection findings over the last three years and to consider whether further action is appropriate.
The Office of Nuclear Reactor Regulation (NRR) performed this analysis, focusing on three likely potential drivers for the decline:
- 1. Implementation of the ROP;
- 2. Decommissioned plants; and
- 3. Trends associated with licensee performance CONTACT:
Shakur Walker, NRR/DIRS 301-415-0107
While NRRs review focused on changes in the 2015 to 2018 timeframe, in some cases the staff analyzed data outside this window to determine if there were any potential impactful changes in the ROP or industry that could have contributed to the trend (e.g., several plants shut down between 2011 and 2016). For this analysis, the staff also leveraged the results of an inspector survey that was conducted in 2018 to obtain insights on potential causes for the trend. Relevant information from the survey is provided at the end of this document.
Based on NRRs analysis, the data shows that the decline in inspection findings can most likely be attributed primarily to implementation of the ROP, specifically the following factors: efforts to improve regional consistency when documenting inspection findings, increased engagement by industry in the findings process, and outcomes related to the agencys initiatives on backfit. The remainder of the document describes the staffs analysis and conclusions.
Analysis
- 1.
Implementation of the ROP In September 2013, the Government Accountability Office (GAO) published a report, GAO 743, Nuclear Power - Analysis of Regional Differences and Improved Access to Information Could Strengthen NRC Oversight (https://www.gao.gov/products/GAO-13-743). Two of the three areas the GAO audit examined were (1) how the NRC implements its processes for overseeing the safety of commercial nuclear power reactors; and (2) the extent to which the NRC consistently identifies and resolves findings through these processes. The report identified that from 2000 to 2012, the number of non-escalated findings not only continued to rise, but there were differences across the regions in identifying and resolving the findings that resulted from variations in regional implementation practices.
The GAO report recommended that to better meet the goal of implementing objective and consistent oversight, NRC managers should conduct a comprehensive analysis of the causes of the differences in the identification and resolution of findings. The NRC staff agreed with this recommendation since it was recognized that there were regional differences in applying the minor and more-than-minor screening thresholds as well as differences in approaches to the number of findings identified for a single issue or condition. Since the 2013 GAO report, NRR and the regions took the following actions to ensure consistency when identifying and assessing findings and issues of concern, including but not limited to:
Provided additional ROP training for inspectors on the interpretation of the more-than-minor questions and identification credit; Established region-specific and cross-regional panels for the review of findings and decision-making related to ROP results; and Increased management oversight of the process used by inspectors to identify and screen findings and performance deficiencies.
The actions taken to improve regional consistency following the GAO audit likely contributed to the downward trend in documented findings. In 2014, the staff performed a table-top exercise where inspectors from each region and Headquarters were given scenarios of potential licensee performance deficiencies and asked to evaluate whether they represented inspection findings (i.e., a performance deficiency that exceeds the more-than-minor threshold described in Inspection Manual Chapter (IMC) 0612). The objective of this exercise was to align staff and management interpretation of the screening questions, with a goal of improving consistency in implementation.
As shown in Figure 1 below, in the years following the GAO audit, major differences in the number of findings across the regions have been reduced.
Finally, in 2017 and 2018, the staff conducted backfit reset training across the agency. This training increased the staffs understanding of NRC backfitting requirements and raised awareness of the potential for introducing a backfit through an inspection finding. While not readily quantifiable, the increased sensitivity to potential backfits may also be a contributor to a reduction in the number of findings.
Overall, the staff believes that efforts to improve consistency in the screening of inspection findings and the agencys increased focus on discipline in applying the backfit rule may have had an impact on the number of overall findings issued in recent years.
- 2.
Decommissioned Plants Figure 2 below shows the contribution of findings from plants that have ceased operation and therefore transitioned out of the ROP since 2014. Of these, only the data from Fort Calhoun Station significantly impacts the time period being assessed from 2015 through 2018. When the findings from Fort Calhoun Station from 2015 are removed, the reduction in findings from 2015 through 2018 drops from 42 percent to 39 percent. Pilgrim Nuclear Power Station has been a significant contributor to overall inspection findings for the past several years. The staff expects to see a further decrease in overall findings in 2019 because of its permanent cessation of operations.
0 50 100 150 200 250 300 350 Total Number of Green Findings Year Figure 1: Green Findings by Region RI RII RIII RIV
Figure 2: Findings for Plants Closed Between 2014 and 2019 Year Fort Calhoun Vermont Yankee Oyster Creek Pilgrim 2014 56 10 11 12 2015 33 1
10 31 2016 11 0
5 23 2017 0
0 3
34 2018 0
0 3
39
- 3.
Trends Associated with Licensee Performance NRR also assessed whether improved licensee performance could be the cause of the decrease in inspection findings. The staff notes that in its development of SECY 19-0067, Recommendations for Enhancing the Reactor Oversight Process, the staff reviewed operating experience information, inspection program data, information from the sunset Industry Trends Program, and other information sources from 2000-2018 to independently assess whether the safety of the operating reactor fleet has demonstrably changed over the life of the ROP. Plant modifications during that time have generally resulted in reduced baseline core damage frequencies for internal events.
In addition, in its Accident Sequence Precursor Program 2018 Annual Report, the NRC concluded that:
Current agency oversight programs and licensing activities remain effective as shown by decreasing 10-year trends in the occurrence rate of all precursors, and Licensee risk management initiatives are effective in maintaining a flat or decreasing risk profile for the industry.
Overall, NRR concluded that there has been an improvement in plant safety over the period (2000-2018) for several areas considered. However, the staff did not identify an appreciable improvement in performance in the period from 2015 to 2018 that could conclusively account for the decrease in inspection findings.
There has been a decrease in licensee event reports (LERs) from 2016 to 2018. Although the number of LERs was down in 2017, it remained within the expected variance; in 2018 though, the drop continued. This is most likely attributed to a modification of reporting under 10 CFR 50.73(a)(2)(v)(D) and 50.73(a)(2)(v)(C). Technical specification task force (TSTF) traveler TSTF-551 was approved in September 2017 (ADAMS Accession No. ML17236A365) that allowed licensees to modify their technical specifications to remove the requirement to write an LER every time they discover a momentary inoperability in secondary containment.
Figure 3: Number of LERs Between 2015 and 2018 Year Number of LERs 2015 305 2016 341 2017 278 2018 222
Insights Provided by NRC Inspection Staff To gather additional insights on potential causes of the trend, the staff reviewed the results of a survey of regional inspectors conducted in 2018. Inspector responses indicated that they had observed an increased focus on ensuring inspection findings were properly vetted and processed consistently through the ROPs issue screening questions and criteria.
For a performance deficiency to be documented as a finding in an NRC inspection report, it must be identified as more-than-minor. Inspectors accomplish this determination by screening each performance deficiency against the more-than-minor threshold questions in IMC 0612 Appendix B, Issue Screening, and examples in Appendix E, Examples of Minor Issues. This process has not changed in the past five years, but anecdotal responses from some of the nearly 250 inspectors who responded to the survey indicate that increased management scrutiny of the issue screening process has resulted in a higher threshold for what qualifies an issue as more-than-minor. This increased scrutiny likely resulted in fewer performance deficiencies being appropriately screened as more-than-minor, causing a corresponding reduction in the number of findings issued. As a separate effort, the staff is drafting a revision to IMC 0612 to improve guidance for inspectors in screening performance deficiencies.
Because minor violations (considered less than very low safety significance) are not tracked, there is no data available to quantitatively determine whether there has been an increase in minor violations to correlate to the decrease in more-than-minor Green findings (i.e., findings of very low safety significance). In their survey responses, several inspectors also commented that industry pushback against potential findings, along with Green and greater-than-Green findings, has increased sharply over the past two to three years. The number of formally disputed inspection findings increased from one in 2013, to five in 2015, and seven in 2018.
Comments from the inspector survey indicate that informal disputes of minor/more-than-minor determinations increased significantly in the 2015 to 2018 timeframe. Inspectors make risk-informed judgements regarding the amount of effort to apply to issues of very low safety significance. The staff is unable to determine with confidence how such judgments affect the total number of documented findings. However, the staff notes that regardless of whether or not an issue is determined to be minor or minor-than-minor, licensees are required to correct any non-compliances identified by the inspectors.
Conclusion In summary, the staff analyzed the decline in inspection findings against several potential contributing factors, including potential impacts related to implementation of the ROP (e.g.,
actions to improve regional consistency); changes in the industry (e.g., plant shutdowns); and industry initiatives to improve licensee performance. The data analyzed by the staff indicates that the reduction in findings is attributed primarily to staff efforts to improve consistent implementation of the ROP (e.g. improving regional consistency, backfit training). While there has been a decline in documented findings, the inspection staff continues to raise issues of concern with licensees, which are captured by the licensees corrective action program and resolved commensurate with their safety significance. The staff will continue to effectively monitor licensee performance, look for efficiencies to be gained in implementation of the ROP through the ROP self-assessment process and other initiatives, and ensure proper oversight remains consistent with the Principles of Good Regulation.
SUBJECT:
ANALYSIS OF INSPECTION FINDINGS TREND AT NUCLEAR POWER REACTORS BETWEEN 2015 AND 2018 DISTRIBUTION: SRM-M190620 RidsNRRDIRSMailCenter CMiller SWalker HNieh ADAMS Accession Number: ML19225D281 OFFICE NRR/DIRS NAME SWalker DATE 8/15/19 OFFICIAL RECORD COPY