ML14105A372
| ML14105A372 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 05/22/2014 |
| From: | Mahesh Chawla Plant Licensing Branch III |
| To: | Vitale A Entergy Nuclear Operations |
| Mahesh Chawla NRR/DORL 415-8371 | |
| References | |
| TAC MF0153 | |
| Download: ML14105A372 (12) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 May 22, 2014 Mr. Anthony J. Vitale Site Vice President Entergy Nuclear Operations, Inc.
Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, Ml 49043-9530
SUBJECT:
PALISADES NUCLEAR PLANT - STAFF ASSESSMENT OF THE SEISMIC WALKDOWN REPORT SUPPORTING IMPLEMENTATION OF NEAR-TERM TASK FORCE RECOMMENDATION 2.3 RELATED TO THE FUKUSHIMA DAI -ICHI NUCLEAR POWER PLANT ACCIDENT (TAC NO. MF0153)
Dear Mr. Vitale:
On March 12, 2012, the U.S. Nuclear Regulatory Comm ission (NRC) issued a request for information letter per Title 10 of the Code of Federal Regulations, Subpart 50.54(f) (50.54(f) letter). The 50.54(f) letter was issued to power reactor licensees and holders of construction permits requesting addressees to provide further information to support the NRC staff's evaluation of regulatory actions to be taken in response to lessons learned from Japan's March 11 , 2011 , Great Tohoku Earthquake and subsequent tsunami. The request addressed the methods and procedures for nuclear power plant licensees to conduct seismic and flooding hazard walkdowns to identify and address degraded , nonconforming , or unanalyzed conditions through the corrective action program, and to verify the adequacy of the monitoring and maintenance procedures.
By letter dated November 27, 2012, Entergy Nuclear Operations, Inc. (Entergy) submitted its Seismic Walkdown Report as requested in Enclosure 3 of the 50.54(f) letter for the Palisades Nuclear Plant. By letter dated November 22, 2013, Entergy provided a response to the NRC request for additional information for the staff to complete its assessments.
The NRC staff acknowledges that a supplemental letter will be provided within three months of the end of the next refueling outage scheduled for January 2014 addressing the remaining inaccessible items consistent with the regulatory commitment. The NRC staff reviewed the information provided and, as documented in the enclosed staff assessment, determined that sufficient information was provided to be responsive to Enclosure 3 of the 50.54(f) letter.
A. Vitale If you have any questions, please contact me at 301-415-8371 or by e-mail at Mahesh. Chawla@nrc.gov Sincerely, Mahesh Chawla, Project Manager Plant Licensing Branch 111-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-255
Enclosure:
Staff Assessment of Seismic Walkdown Report cc w/encl: Distribution via Listserv
STAFF ASSESSMENT OF SEISMIC WALKDOWN REPORT NEAR-TERM TASK FORCE RECOMMENDATION 2.3 RELATED TO THE FUKUSHIMA DAI-ICHI NUCLEAR POWER PLANT ACCIDENT ENTERGY NUCLEAR OPERATIONS . INC.
PALISADES NUCLEAR PLANT DOCKET NO. 50-255
1.0 INTRODUCTION
On March 12, 2012,1 the U.S. Nuclear Regulatory Commission (NRC) issued a request for information per Title 10 of the Code of Federal Regulations, Subpart 50.54(f) (50.54(f) letter) to all power reactor licensees and holders of construction permits in active or deferred status. The request was part of the implementation of lessons learned from the accident at the Fukushima Dai-ichi nuclear power plant. Enclosure 3, "Recommendation 2.3: Seismic," 2 to the 50.54(f) letter requested licensees to conduct seismic walkdowns to identify and address degraded, nonconforming , or unanalyzed conditions using the corrective action program (CAP), verify the adequacy of monitoring and maintenance procedures, and report the results to the NRC .
The 50.54(f) letter requested licensees to provide the following:
- a. Information concerning the plant-specific hazard licensing bases and a description of the protection and mitigation features considered in the licensing basis evaluation.
- b. Information related to the implementation of the walkdown process.
- c. A list of plant-specific vulnerabilities identified by the Individual Plant Examination of External Events (I PEEE) program and a description of the actions taken to eliminate or reduce them .
- d. Results of the walkdown including key findings and identified degraded ,
nonconforming , or unanalyzed conditions .
- e. Any planned or newly installed protection and mitigation features.
- f. Results and any subsequent actions taken in response to the peer review.
In accordance with the 50.54(f) letter, Enclosure 3, Required Response Item 2, licensees were required to submit a response within 180 days of the NRC's endorsement of the seismic 1
Agencywide Documents Access and Management System (ADAMS) Accession No. ML12053A340 2
ADAMS Accession No. ML12056A049 Enclosure
walkdown process. By letter dated May 29, 2012, 3 the Nuclear Energy Institute (NEI) staff submitted Electric Power Research Institute document 1025286, "Seismic Walkdown Guidance for Resolution of Fukushima Near-Term Task Force Recommendation 2.3: Seismic," (walkdown guidance) to the NRC staff to consider for endorsement. By letter dated May 31, 2012, 4 the NRC staff endorsed the walkdown guidance.
By letter dated November 27, 2012, 5 Entergy Nuclear Operations, Inc. (the licensee) provided a response to Enclosure 3 of the 50.54(f) letter Required Response Item 2, for the Palisades Nuclear Plant (PNP). The NRC staff reviewed the walkdown report and determined that additional supplemental information would assist the staff in completing its review. By letter dated November 1, 2013 6 , the NRC staff requested additional information to gain a better understanding of the processes and procedures used by the licensee in conducting the walkdowns and walk-bys. The licensee responded to the NRC staff request by letter dated November 22, 2013. 7 The NRC staff evaluated the licensee's submittals to determine if the information provided in the walkdown report met the intent of the walkdown guidance and if the licensee responded appropriately to Enclosure 3 of the 50.54(f) letter.
2.0 REGULATORY EVALUATION
The structures, systems, and components (SSCs) important to safety in operating nuclear power plants are designed either in accordance with , or meet the intent of Appendix A to 10 CFR Part 50, General Design Criteria (GDC) 2: "Design Bases for Protection Against Natural Phenomena;"
and Appendix A to 10 CFR Part 100, "Reactor Site Criteria." GDC 2 states that SSCs important to safety at nuclear power plants shall be designed to withstand the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, floods, tsunami , and seiches without loss of capability to perform their safety functions.
For initial licensing, each licensee was required to develop and maintain design bases that, as defined by 10 CFR 50.2, identify the specific functions that an sse of a facility must perform, and the specific values or ranges of values chosen for controlling parameters as reference bounds for the design.
The design bases for the SSCs reflect appropriate consideration of the most severe natural phenomena that have been historically reported for the site and surrounding area. The design bases also reflect sufficient margin to account for the limited accuracy, quantity, and period of time in which the historical data have been accumulated .
The current licensing basis is the set of NRC requirements applicable to a specific plant, including the licensee's docketed commitments for ensuring compliance with, and operation within, applicable NRC requirements and the plant-specific design basis, including all modifications and additions to such commitments over the life of the facility operating license.
3 ADAMS Package Accession No. ML121640872 4
ADAMS Accession No. ML12145A529 5
ADAMS Accession No. ML12334A093 6
ADAMS Accession No. ML133048418 7
ADAMS Accession No. ML13329A230
3.0 TECHNICAL EVALUATION
3.1 Seismic Licensing Basis Information The licensee provided information on the plant-specific licensing basis for the Seismic Category I SSCs for PNP in Section 2.0 of the walkdown report. Consistent with the walkdown guidance, the NRC staff noted that the report includes a summary of the Design Basis Earthquake (DBE) and a description of the codes, standards, and methods that were used in the design of the Seismic Category I SSCs for meeting the plant-specific seismic licensing basis requirements .
Based on the NRC staff's review, the staff concludes that the licensee has provided information on the plant-specific seismic licensing basis and a description of the protection and mitigation features considered in the licensing bases evaluation consistent with Section 8, Submittal Report ,
of the walkdown guidance.
3.2 Seismic Walkdown Methodology Implementation Section 2, Personnel Qualifications; Section 3, Selection of SSCs; Section 4, Seismic Walkdowns and Area Walk-Bys; and Section 5, Seismic Licensing Basis Evaluations, of the walkdown guidance provide information to licensees regarding the implementation of an appropriate seismic walkdown methodology. By letter dated July 9, 2012,8 the licensee confirmed that it would utilize the walkdown guidance in the performance of the seismic walkdowns at PNP.
The walkdown report dated November 27, 2012, did not identify deviations from the walkdown guidance.
The NRC staff reviewed the following sections of the walkdown methodology implementation provided in the walkdown report:
- Personnel Qualifications
- Development of the Seismic Walkdown Equipment Lists (SWELs)
- Implementation of the Walkdown Process
- Licensing Basis Evaluations and Results 3.2.1 Personnel Qualifications Section 2, Personnel Qualifications, of the walkdown guidance provides licensees with qualification information for personnel involved in the conduct of the seismic walkdowns and area walk-bys.
The NRC staff reviewed the information provided in Section 4, and Appendix H of the walkdown report, which includes information on the walkdown personnel and their qualifications.
Specifically, the staff reviewed the summary of the background, experience, and level of involvement for the following personnel involved in the seismic walkdown activities: equipment selection personnel, seismic walkdown engineers (SWEs) , licensing basis reviewers , IPEEE reviewers, peer review team , and operations staff.
8 ADAMS Accession No. ML12192A203
Based on the review of the licensee's submittals, the NRC staff concludes that those involved in the seismic walkdown activities have the appropriate seismic background , knowledge and experience, as specified in Section 2 of the walkdown guidance.
3.2.2 Development of the SWELs Section 3, Selection of SSCs, of the walkdown guidance provides information to licensees for selecting the SSCs that should be placed on the SWELs, so that they can be walked down by qualified personnel.
The NRC staff reviewed the overall process used by the licensee to develop the PNP base list, SWEL 1 (sample list of designated safety functions equipment), and SWEL 2 (sample list of spent fuel pool related equipment). The overall equipment selection process followed the screening process shown in Figures 1-1 and 1-2 of the walkdown guidance. Based on Tables 9.4.2 and 9.4.5 of Attachment B of the walkdown report, PNP SWELs 1 and 2 meet the inclusion requirements of the walkdown guidance. Specifically, the following attributes were considered in the sample selection:
- A variety of systems, equipment and environments
- IPEEE equipment
- Major new or replacement equipment
- Risk considerations Due to individual plant configurations and the walkdown guidance screening process followed to select the final SWEL equipment, it is possible that some classes of equipment will not be represented on the SWEL. The walkdown guidance recognizes this is due to the equipment not being present in the plant (e.g., some plants generate DC power using inverters and therefore do not have motor generators) or the equipment being screened out during the screening process as described in Section 3 of the walkdown guidance. Based on the information provided , the NRC staff noted that a detailed explanation was provided justifying cases where specific classes of equipment were not included as part of the SWEL, and concludes that these exclusions are acceptable.
The NRC staff noted that no rapid drain-down items were included as part of the SWEL 2, as described in Section 3 of the guidance. In Attachment B, Table 9.4.4 of the walkdown report, the licensee stated that there is no piping or equipment connected to the Spent Fuel Pool (SFP) that can cause rapid drain-down . The staff noted that Section 9.1 of the walkdown report states that the peer review team reviewed and agreed with the licensee in that "Palisades does not have SFP penetrations below 10 feet above the top of the fuel assemblies. Since there are no such penetrations, no rapid drain-down items were included in SWEL 2". The NRC staff concludes that the screening process described in Table 1-2, specifically Screening 4, was appropriately followed and the overall SWEL 2 was developed in accordance with the guidance.
After reviewing SWELs 1 and 2, the NRC staff concludes that the sample of SSCs represents a diversity of component types and assures inclusion of components from critical systems and functions, thereby meeting the intent of the walkdown guidance. In addition , the NRC staff notes that the equipment selection personnel were appropriately supported by plant operations staff as described in the walkdown guidance.
3.2.3 Implementation of the Walkdown Process Section 4, Seismic Walkdowns and Area Walk-Bys , of the walkdown guidance provides information to licensees regarding the conduct of the seismic walkdowns and area walk-bys for each site.
The NRC staff reviewed Section 7 of the walkdown report, which summarizes the results of the seismic walkdowns and area walk-bys, including an overview of the number of items walked down and the number of areas walked-by. The walkdown report states that seismic walkdowns and area walk-bys were conducted by two teams of two trained and qualified SWEs over the course of three weeks during October 2012. The walkdown report also states that the SWEs discussed their observations and judgments with each other during the walkdowns . Additionally, the SWEs agreed on the results of their seismic walkdowns and area walk-bys before reporting the results of their review. Appendices C and D of the walkdown report provide the completed seismic walkdown checklists (SWCs) and area walk-by checklists (AWCs) , documenting the results for each item of equipment on SWEL 1 and 2 and each area containing SWEL equipment. The licensee used the checklists provided in Appendix C of the walkdown guidance report without modification.
The licensee documented cases of potentially adverse seismic conditions (PASCs) in the checklists for further evaluation. Attachment E of the walkdown report lists the PASCs identified during the seismic walkdowns and the area walk-bys . The table describes how each condition was addressed (e.g., placement in the CAP), its resolution and current status. Based on the review of the checklists, the staff was unable to confirm that all the PASCs identified during the walkdowns were included in this table .
By letter dated November 1, 2013, the staff issued two questions in a request for additional information (RAI) in order to obtain additional clarification regarding the process followed by the licensee when evaluating conditions identified in the field during the walkdowns and walk-bys.
Specifically, in RAI 1 the staff requested the licensee to provide further explanation regarding how a field observation was determined to be a PASC, and to ensure that the basis for determination was addressed using normal plant processes and documented in the walkdown report. In response to RAI 1, the licensee provided additional clarification and confirmed that observations that could not be readily judged to be acceptable with respect to its current licensing basis during the walkdown , were identified as PASCs on the SWCs and AWCs . These PASCs were further evaluated in the field and if the condition was determined to be unusual or uncertain, it was then either addressed via a licensing-basis evaluation (LBE) or entered into the CAP for resolution .
The licensee referred to Section 8.0 of the walkdown report which includes a description of all these items. Furthemiore, the licensee stated that LBE items not readily concluded through the process to meet their current licensing basis (CLB) were entered directly into the CAP.
Attachment E of the walkdown report provides a list of these conditions , describes how each condition was addressed, and its current status. The licensee confirmed that the reported information supports the conclusion that the plant meets its CLB, that no new conditions were identified, and all the items were addressed and properly included in the walkdown report.
After evaluating the licensee's response and reviewing Attachment E of the walkdown report, the NRC staff concludes that the licensee responded appropriately to RAI 1, PASCs were properly identified and documented, and Attachment E is considered complete. Furthermore, the
licensee committed to resolve all the PASCs and associated condition reports identified in Section 8.2 of the walkdown report by December 31 , 2014.
In addition to the information provided above, the NRC staff notes that anchorage configurations were verified to be consistent with existing plant documentation for at least 50 percent of the SWEL items, in accordance with Section 4 of the walkdown guidance.
Section 7.1 of the walkdown report states that cabinets that could be inspected safely were opened to verify their internal components . The NRC staff reviewed the seismic walkdown checklists and confirmed that cabinets and panels were opened to determine if any adverse conditions existed of internal equipment.
The equipment and areas that were inaccessible during the 180-day period are listed in Section 6.3 of the walkdown report. This section also includes the condition which caused the delay of the walkdown . A limited number of SWEL components (total of eight) were inaccessible at the time of the initial walkdowns . The licensee stated that the internally mounted items on five electrical cabinets were inaccessible due to the energized nature of the cabinets . The staff noted that the external anchorage conditions and the immediate area surrounding these components were included during the initial walkdown and documented in the checklists . The other three SWEL components were located in areas that were inaccessible while the plant was at power.
The walkdowns for all of the remaining inaccessible items were committed to be completed by the end of the next scheduled refueling outage (October 2013). However, this refueling outage was postponed to January 2014 and the licensee committed to provide a supplemental submittal with the results of these walkdown items within three months of the end of the January 2014 refueling outage.9 Based on the information provided in the licensee's submittals, the NRC staff concludes that the licensee's implementation of the walkdown process meets the intent of the walkdown guidance.
3.2.4 Licensing Basis Evaluations and Results Section 5, Seismic Licensing Basis Evaluations, of the walkdown guidance provides information to licensees regarding the conduct of licensing basis evaluations for items identified during the seismic walkdowns as degraded, nonconforming, or unanalyzed that might have potential seismic significance.
The NRC staff reviewed Section 8.2 of the PNP Walkdown Report, which discusses the process for conducting the seismic licensing basis evaluations of the PASCs identified during the seismic walkdowns and area walk-bys. The licensee stated that PASCs identified during the seismic walkdowns and area walk-bys were included in Attachment E of the walkdown report. Each PASC was then addressed either with a LBE to determine whether it required entry into the CAP, or by entering it into the CAP directly. The licensee stated the decision to conduct a LBE or using the CAP directly was made on a case-by-case basis. Attachment F of the walkdown report documents the results of each LBE.
9 ADAMS Accession No. ML13269A094
potentially degraded, nonconforming , or unanalyzed conditions and entered them into the CAP, which meets the intent of the walkdown guidance.
3.2.5 Conclusion Based on the discussion above, the NRC staff concludes that the licensee's implementation of seismic walkdown methodology meets the intent of the walkdown guidance for personnel qualifications, development of SWELs, implementation of the walkdown process, and seismic licensing basis evaluations.
3.3 Peer Review Section 6, Peer Review, of the walkdown guidance provides licensees with information regarding the conduct of peer reviews for the activities performed during the seismic walkdowns. Page 6-1 of the walkdown guidance identifies the following activities to be conducted during the peer review process:
- Review a sample of the checklists prepared for the seismic walkdowns and area walk-bys
- Review the licensing basis evaluations
- Review the decisions for entering the potentially adverse conditions into the CAP
- Review the walkdown report
- Summarize the results of the peer review process in the walkdown report The NRC staff reviewed the information provided in Section 9, Attachment G and J of the PNP Walkdown Report which describes the conduct of the peer review. In addition, the staff reviewed the response to RAI 2. In RAI 2, the NRC staff requested the licensee to provide additional information on the overall peer review process that was followed as part of the walkdown activities. Specifically, the staff requested the licensee to confirm that the activities identified in page 6-1 of the walkdown guidance were assessed and documented in the report. The licensee was also requested to confirm that any individual involved in performing any given walkdown activity was not a peer reviewer for that same activity. In response to RAI 2, the licensee confirmed that all the activities identified on page 6-1 of the walkdown guidance were included as part of the peer review process and referred to the summary of the peer review activities provided in Section 9 of the walkdown report. In addition , the licensee provided additional information on the level of involvement of the peer review team in order to further demonstrate the independence of the peer review process.
The NRC staff reviewed the licensee's summary of each of these activities, which included the peer review team members' level of involvement, the peer review findings, and resolution of peer review comments . After reviewing the licensee's submittals, the NRC staff concludes that the licensee sufficiently documented the results of the peer review activities and how these reviews affected the work described in the walkdown report.
Based on the discussion above, the NRC staff concludes that the licensee's results of the peer review and subsequent actions taken in response to the peer review meets the intent of Section 6 of the walkdown guidance.
3.4 IPEEE Information Section 7, IPEEE Vulnerabilities , of the walkdown guidance provides information to licensees regarding the reporting of the evaluations conducted and actions taken in response to seismic vulnerabilities identified during the IPEEE program. Through the IPEEE program and Generic Letter 88-20, "Individual Plant Examination of External Events for Severe Accident Vulnerabilities ," licensees previously had performed a systematic examination to identify any plant-specific vulnerabilities to severe accidents.
The licensee provided background information regarding their IPEEE program. The licensee stated that certain relays were identified as outliers were included in the USI A-46 Seismic Qualification Users Group (SQUG) programs and were dispositioned as SQUG outliers.
Resolution of these A-46 outliers also resolved the IPEEE vulnerabilities . The identified seismic vulnerabilities (outlier relays) were reported in Attachment A of the walkdown report . The licensee stated that all these items have been resolved and no further action is required .
Based on the NRC staff's review of Section 5 of the walkdown report , the staff concludes that the licensee's identification of plant-specific vulnerabilities (including anomalies, outliers and other findings) identified by the IPEEE program , as well as actions taken to eliminate or reduce them ,
meets the intent of Section 7 of the walkdown guidance.
3.5 Planned Upgrades The licensee did not identify any planned or newly installed protection and mitigation features in the walkdown report.
3.6 NRC Oversight 3.6.1 Independent Verification by Resident Inspectors On July 6, 2012,10 the NRC issued Temporary Instruction (TI) 2515/188 "Inspection of Near-Term Task Force Recommendation 2.3 Seismic Walkdowns. " In accordance with the Tl, NRC inspectors independently verified that the PNP implemented the seismic walkdowns in accordance with the walkdown guidance. Additionally, the inspectors independently performed walkdowns of a sample of seismic protection features . The inspection report dated February 11 ,
2013,11 documents the results of this inspection and states that no findings were identified.
10 ADAMS Accession No. ML12156A052 11 ADAMS Accession No. ML13042A051
4.0 INACCESSIBLE ITEMS The equipment and areas that were inaccessible during the 180-day period are listed in Section 6-3 of the walkdown report. The list of inaccessible items also includes the condition which caused the delay of the walkdown . As discussed above, a limited number of SWEL components (total of eight) were inaccessible at the time of the initial walkdowns. The walkdowns for all of the remaining inaccessible items were committed to be completed by the end of the next scheduled refueling outage in January 2014, and a supplemental submittal with the results of these walkdown items will be provided within three months of the end of the January 2014 refueling outage.
5.0 CONCLUSION
The NRC staff concludes that the licensee's implementation of seismic walkdown methodology meets the intent of the walkdown guidance. The staff concludes that, through the implementation of the walkdown guidance activities and, in accordance with plant processes and procedures, the licensee verified the plant configuration with the current seismic licensing basis; addressed degraded, nonconforming , or unanalyzed seismic conditions; and verified the adequacy of monitoring and maintenance programs for protective features . Furthermore, the NRC staff notes that no immediate safety concerns were identified. The staff acknowledges that a supplemental letter will be provided within three months of the end of the next refueling outage scheduled for January 2014 addressing the remaining inaccessible items consistent with the regulatory commitment. The NRC staff reviewed the information provided and determined that sufficient information was provided to be responsive to Enclosure 3 of the 50.54(f) letter.
A. Vitale If you have any questions , please contact me at 301-415-8371 or by e-mail at Mahesh .Chawla@nrc.gov Sincerely ,
IRA/
Mahesh Chawla , Project Manager Plant Licensing Branch 111-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-255 Enclosure :
Staff Assessment of Seismic Walkdown Report cc w/encl: Distribution via Listserv DISTRIBUTION :
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