ML13308C286
| ML13308C286 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 02/06/2014 |
| From: | John Hughey Plant Licensing Branch 1 |
| To: | Joyce T Public Service Enterprise Group |
| Hughey J | |
| References | |
| TAC MF0276, TAC MF0277 | |
| Download: ML13308C286 (11) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. Thomas Joyce President and Chief Nuclear Officer PSEG Nuclear LLC-N09 P. 0. Box 236 Hancocks Bridge, NJ 08038 February 6, 2014
SUBJECT:
SALEM NUCLEAR GENERATING STATION, UNITS 1 AND 2-AUDIT REPORT REGARDING FLOODING WALKDOWNS TO SUPPORT IMPLEMENTATION OF NEAR-TERM TASK FORCE RECOMMENDATION 2.3 RELATED TO THE FUKUSHIMA DAI-ICHI NUCLEAR POWER PLANT ACCIDENT (TAC NOS. MF0276 AND MF0277)
Dear Mr. Joyce:
On March 12, 2012, the U.S. Nuclear Regulatory Commission staff (NRC or the staff) issued a request for information letter per Title 10 of the Code of Federal Regulations, Section 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 plants 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 26, 2012, PSEG Nuclear, LLC (PSEG) submitted a Flooding Walkdown Report as requested per Enclosure 4 of the 50.54(f) letter for Salem Nuclear Generating Station, Units 1 and 2. On June 27, 2013, an NRC audit team completed the on-site audit to gain a better understanding of the methods and procedures used by PSEG to conduct the flooding walkdowns. The information gained during the audit will facilitate the NRC staff review of the walkdown report and allow for more concise requests for information. The NRC staff appreciates your support of the audit. The final audit report has been included as an enclosure to this letter.
If you have any questions, please contact Mr. John Hughey at 301-415-3204 or by e-mail at john.hughey@nrc.gov.
Docket Nos. 50-272 and 50-311
Enclosure:
Audit Report cc w/encl: Distribution via Listserv Si;ii2D.~
John D. Hughey, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Regulation Office of Nuclear Reactor Regulation
REPORT OF REGULATORY AUDIT ON JUNE 25 TO JUNE 27, 2013 FLOODING WALKDOWNS PSEG NUCLEAR, LLC SALEM NUCLEAR GENERATING STATION, UNITS 1 AND 2 DOCKET NOS. 50-272 AND 50-311
- 1.
Introduction This document provides a summary of the United States Nuclear Regulatory Commission (NRC) audit of the flooding walkdowns performed by Salem Nuclear Generating Station (Salem), Units 1 and 2. The walkdowns were performed in response to the NRC's request for information contained in the March 12, 2012, 1 letter, Enclosure 4.
1.1 Background
By letter dated March 12, 2012, the NRC issued a request for information to all power reactor licensees and holders of construction permits in active or deferred status, pursuant to Title 1 0 of the Code of Federal Regulations, Section 50.54(f) (hence referred to as the 50.54(f) letter). The request was issued as a part of implementing lessons-learned from the accident at the Fukushima Dai-ichi, Japan, nuclear power plant. Enclosure 4 of the 50.54(f) letter requested that licensees plan and perform a flooding walkdown to identify degraded, nonconforming, or unanalyzed conditions related to the licensing bases of structures, systems, and components (SSCs) important to safety and to verify the adequacy of the monitoring and maintenance procedures.
By letter dated November 26, 2012, 2 PSEG Nuclear, LLC (PSEG) submitted a repore documenting the flooding walkdowns as requested per Enclosure 4 of the 50.54(f) letter for Salem, Units 1 and 2.
1.2 Regulatory Audit Basis The NRC staff conducted a regulatory audit to gain a better understanding of the methods and associated procedures used by PSEG Nuclear, LLC to conduct the flooding walkdowns at Salem, Units 1 and 2, and to facilitate the NRC staff assessment of the report documenting the site walkdowns.
The Nuclear Energy Institute (NEI) developed guidance for performing the flooding walkdowns with extensive review and input from NRC staff in numerous public meetings, webinars, and public conference calls. NEI submitted NEI 12-07, "Guidelines for Performing Verification 1 Agencywide Documents Access and Management System (ADAMS) Accession No. ML12053A340.
2 ADAMS Accession No. ML12334A450.
3 ADAMS Accession No. ML12334A451.
Enclosure Walkdowns of Plant Flood Protection Features,"4 for endorsement. The NRC staff subsequently endorsed the walkdown guidance by letter dated May 31, 2012.5 By letter dated June 12, 2012, PSEG Nuclear, LLC confirmed that it will use the NRC-endorsed guidance, NEI12-07, as the basis for the flooding walkdowns at Salem, Units 1 and 2.6 1.3 Audit Logistics An audit plan was issued to PSEG Nuclear, LLC on May 20, 2013.7 The audit plan included a proposed audit schedule and a list of information that NRC requested the licensee to make available for review during the audit. The audit plan also requested that the personnel (licensee staff and contractors) who performed the walkdowns be available for interviews.
The NRC staff performed an audit of Salem, Units 1 and 2, on June 25-27, 2013. The audit was performed in accordance with the Office of Nuclear Reactor Regulation (NRR) Office Instruction LIC-111, "Regulatory Audits."8 The NRC staff and contractors participating in the audit are listed in Table 1. It is to be noted that the audit of Salem, Units 1 and 2, was conducted concurrently with the audit of Hope Creek Generating Station, since both sites are adjacent to each other and owned by PSEG, LLC.
An entrance meeting was held on June 25, 2013, to convey to the licensee background information and the purpose of the audit. An exit meeting was held on June 27, 2013, to convey to the licensee observations from the audit, including: (1) observations related to whether the walkdowns were performed in accordance with NEI 12-07; and (2) observations forwarded to the resident inspectors for additional action, if appropriate.
Auditor Stephen Campbell Nebiyu Tiruneh Michelle Bensi Jacob Philip Sherlyn lbarrola George Wilson Ed Miller Terri Patton John Quinn 4 ADAMS Accession No. ML12144A401.
5 ADAMS Accession No. ML12144A142.
6 ADAMS Accession No. ML12160A292.
7 ADAMS Accession No. ML13127A455.
8 ADAMS Accession No. ML082900195.
Table 1: NRC Audit Team Affiliation Audit Role NRC/NRRIDIRS/IRIB Audit Team Lead NRC/NRO/DSEA/RHMB Technical Lead NRC/NRO/DSEA/RHMB Audit Team Member NRC/RES/DRAIETB Audit Team Member NRC/R-I/DRP/PB3/HCRO Resident Inspector NRC/NRRIDORLILPL 1-1 Management Support NRC/NRRIJLD/PMB Audit Team Member Argonne National Laboratory Audit Team Member Argonne National Laboratory Audit Team Member
- 2.
Audit Scope The audit provides support for the ongoing NRC staff assessment of the licensee-submitted walkdown report. The audit scope included review of information and documents available onsite and interviews of licensee staff and contractors to aid NRC staff understanding of:
(1) how the licensee performed the flooding walkdowns, and (2) whether the walkdowns were performed in accordance with NEI 12-07.
The audit also helped to identify additional information that will require docketing to support the staff conclusions related to the staff assessment. Observations made by the audit team that were not within the scope of the audit were transferred to the resident inspector for additional action, if appropriate.
- 3.
Audit Activities The NRC staff prepared a preliminary list of questions, which were communicated to the licensee prior to the arrival of the team on site. The preliminary list of questions addressed the following topical areas:
Evaluation and disposition of available physical margin (APM) information in light of statements made by the licensee in the walkdown report regarding flood heights and flood protection elevations at the intake structure; Disposition via the corrective action program (CAP) of potential deficiencies identified in Attachment A of the licensee's walkdown report; Computation of APM for barriers and penetration seals; Identification and disposition of flood protection features associated with small or negative margin; and Disposition of observations of cracking, missing seals, leakage (or signs of historical leakage), rust, calcification, or seal degradation.
Throughout the audit, the licensee addressed the staff's questions related to the above topics and provided clarification with regard to the processes used to: compute APM, identify and address potential deficiencies, assess and disposition observations not immediately judged to be acceptable, and address instances of small (or potentially negative) margin.
The audit activities included reviewing the information provided by PSEG, participating in a site familiarization tour of the plant, and holding discussions with PSEG staff. The licensee was also asked to address issues related to the processes used to:
Compute APM, identify and address potential deficiencies, Perform reasonable simulation to assess and disposition observations not immediately judged to be acceptable, and Address instances of small (or potentially negative) margin.
The audit team also interviewed site personnel and walkdown participants to inquire about:
(1) performance of visual inspections (e.g., to discuss criteria used to determine feature acceptability); (2) calculation of APM and consideration of safety consequences associated with any instances of small margin; and (3) estimation of time required to perform manual actions.
In addition, the audit team reviewed documents related to the licensee's performance of the flooding walkdowns, including:
Walkdown record forms, and other supplemental forms and worksheets generated by the licensee to document observations associated with the walkdowns for the Auxiliary Building, Diesel Enclosure, Service Water Intake Structure, Containments/Shore Protection and Reasonable Simulation.
Flood-specific procedures that are part of flood protection strategy and severe weather response that were reviewed or used by the licensee as part of the flood walkdowns.
Listing of entries into the CAP resulting from the performance of the flood walkdowns.
The "Check-in Self-Assessment Report" generated by the licensee to evaluate the status of the Salem flooding walkdowns.
Site plans and maps, as well as relevant plant drawings.
Procedures and logs relevant to plant response to Hurricane Sandy.
Relevant sections of the Updated Final Safety Analysis Report (UFSAR) for the site.
The walkdown record forms at Salem, Units 1 and 2 were comprised of two parts: (1) a copy of the walkdown record form contained in Appendix B of NEI 12-07 that was generically populated for each class of flood protection features (e.g., penetration seals, flood doors, structural walls);
and (2) a detailed spreadsheet containing information on each individual flood protection feature included in the walkdown scope (e.g., the spreadsheet contained an entry for each individual penetration seal, flood door, and credited structural wall). As part of the audit, a sample of entries from the spreadsheet was reviewed for the reactor buildings, auxiliary building, service water intake structure, and rad waste building.
The audit team divided the review responsibilities based on buildings and structures and reviewed a reasonable sample of structures and features such as walls, doors, and seals. A sampling approach was used due to a large number of features in the walkdown record (i.e.,
2790). The review included information related to: material condition, critical design characteristics, the capability of equipment to be operated as expected, APM (including flood height at locations of features and capacity/rating of the features), whether features with small margin were entered into the CAP, and associated CAP notifications. The audit team also reviewed information in the walkdown records related to observed material condition, the seal capacity rating relative to flood level, the reported flood level relative to the elevation maps (if specified) or the UFSAR, and the APM calculation. For those features with CAP notification numbers, their status in the CAP program was verified. During the audit, the audit team noted the following:
Flood heights used to calculate APM for some features were not consistent with the design-basis flood height for the site. In response to NRC staff questions, the licensee explained that the reason for this difference was that the evaluation of APM for some walls and doors considered a limiting flood height that was relevant to defining the structural capacity of the feature, rather than being based on the design-basis flood elevation. Consequently, the evaluation of APM for these walls and doors considered structural capacity, but did not consider the potential for overtopping of barriers due to feature height.
The licensee completed Question 27 (related to identification of whether small margin and significant consequences appear to exist) of the walkdown record forms from Appendix B of NEI 12-07 on a generic basis (e.g., for each "class" of flood protection features) rather than on a feature-specific basis. As a result, individual features with small margin were not associated with a resulting evaluation of safety consequences or entrance into the CAP.
While APM was systematically evaluated at the site on a feature-specific basis (e.g., for each individual seal or door), the limiting APM associated with composite barriers (e.g.,
a flood barrier comprised of structural components, flood doors, and penetration seals) was not identified.
Notifications were initiated for features that were inaccessible or determined to have restricted access, when the material condition was unacceptable, and, in some cases, when the APM was zero. All of the notifications that were reviewed were reported to have been completed at the time of the audit.
The walkdown record spreadsheet did not address question 2 (related to preventative maintenance programs) and question 3 (related to periodic testing) from the walkdown record form in Appendix B of NEI 12-07, but the audit team was able to review general documentation identifying concrete structures and components that are inspected and maintained. The document did not describe how seals are inspected and maintained but further discussions with plant personnel indicated seals are inspected periodically.
In addition, the audit team reviewed the reasonable simulations performed by the procedures, OP-M-108-11-1001, Revision 7, "Severe Weather and Natural Disaster Guidelines," and HC.OP-AB.MISC-0001 (Q), Revision 21, "Acts of Nature." The NRC staff conducted field walkdowns and interviewed licensee personnel regarding the implementation of the procedures.
The audit team noted the following as part of the review:
Prior to the performance of the flood walkdowns, the licensee recently executed the flood specific procedure for an actual event. Therefore, no reasonable simulation was performed during the walkdowns and conclusions made regarding manual actions were based on actual performance data.
A review of the logs and procedures from previous events verified the ability of the licensee to perform required activities within the associated timelines (e.g., shut and "dog" a series of watertight doors within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />).
The licensee did not perform reasonable simulation of activities that they identified as asset protection (e.g., placement of sand bag walls around several door openings).
The audit team also observed that the UFSAR indicates that "[r]oof slabs are watertight to prevent building interiors from being damaged by severe rainstorms. The slabs are designed to withstand a loading equivalent to a depth of water up to the full height of the building's parapet or roof curb." The licensee did not include the roofs of structures within the walkdown scope.
The licensee indicated that a walkdown of the roof was out of scope.
Based on the audit team's reviews, NRC staff has several observations directly related to whether the licensee performed the audit in accordance with NEI12-07. Those observations are described in Section 4.1 of this audit summary.
- 4.
Audit Summary As described in Section 2, the goal of the audit was to support the development of the staff assessment of the licensee's walkdown report. Observations made by the audit team during the audit were compiled and conveyed to the licensee during the exit meeting. These observations are neither findings nor violations; however, they will be used to inform the NRC staff assessment of the licensee's walkdown report.
4.1 Observations Related to NE112-07 The audit team made observations during the audit directly related to the scope of the audit (see Section 3). These observations are described below.
Section 5.8, "Documentation of Available Physical Margin," of NEI 12-07 states that information on APM should be collected and documented in the walkdown record forms. In addition, if the APM of a flood protection feature appears to be small and the consequences of flooding at that location appear to be significant, the condition should be entered into the CAP. The CAP disposition should consider the size of the margin and the consequences of flooding the area affected by the flood protection. Once entered into the CAP, licensees are to take appropriate actions. In consultation with licensee staff, NRC staff learned that there were three "classes" of small margin identified by the licensee:
- 1. "Administratively small (or zero)" margin: During the walkdowns, the licensee encountered challenges associated with documentation of capacity for some flood protection features. While the licensee believes that these features are capable of withstanding flood events larger than the design-basis flood, existing documentation is only available to demonstrate that flood protection features are capable of withstanding the design-basis flood. These features were thus assigned an APM of zero and classified as having "administratively small (or zero)" margin. The licensee has initiated a "margin recovery effort" to better quantify available margin to supplement existing documentation.
- 2. Seals of unknown capacity: The site has flood protection seals for which the seal capacity is unknown (typically due to documentation issues). The licensee assigned an APM of zero to such seals given that design control or similar processes are intended to assure features are able to meet the licensing basis.
- 3. Verified small margin: This classification is used to identify flood protection features that are capable of withstanding the design-basis flood, but with small margin available to withstand larger floods.
Initially, the licensee indicated to the audit team that the only instances of small margin at the site were either: ( 1) "administratively small (or zero)" margin (i.e., class 1 above); or (2) associated with seals of unknown capacity (i.e., class 2 above). For this reason, the licensee did not believe that it was necessary to evaluate safety consequences of small margin for any flood protection features. However, as a result of NRC staff questions during the audit, the licensee identified five penetration seals at the site with verified small margin for which safety consequences were not considered. In accordance with NEI 12-07, instances of small margin should have been documented in PartE, of Question 27 of the walkdown record form. The licensee initiated a CAP notification in response to NRC observations.
The concept of APM relates to the additional flood height and associated effects that a site can sustain prior to the loss of a function provided by an SSC. The licensee's determination of APM values focuses on each individual component or feature, but does not integrate these values at a building or system level. For example, a number of seals credited to support access hatches on the roof of the Salem, Unit 1 service water intake structure (e.g., C-16901-001 thru -008) are listed as having a large APM; however, unsealed (and un-credited) penetrations leading to necessary HVAC equipment exist at a level lower than the listed APM.
The NRC staff reviewed the section of the walkdown report involving reasonable simulation. To evaluate the effectiveness of the licensee's use of reasonable simulation, the NRC staff evaluated the procedures, OP-AA-1 08-11-1001, Revision 7, "Severe Weather and Natural Disaster Guidelines," and SC.OP-AB.22-0001(Q), Revision 14, "Adverse Environmental Conditions."
The NRC staff reviewed the simulations that were performed by the licensee for ensuring water tight integrity and the staging of portable dewatering equipment and concluded that they were reasonable. During the walkdown, the licensee identified that there was not a specific implementing procedure for the dewatering pumps or for specific preventive maintenance requirements on the portable dewatering pumps. The licensee is presently developing both of these documents. The NRC staff also questioned the licensee on why the wave walls were not installed in accordance with OP-AA-1 08-111-1001.
4.2 Observations Communicated to Resident Inspectors The audit team made observations related to the plant response to flooding hazards that were not directly related to the scope of the audit:
Penetration seals E-15557 -002 and E-25549-013 located in the auxiliary building for Salem, Units 1 and 2, were checked from the inside and determined to be satisfactory while joint and seal cracks were present on the outside. The outside cracks were not identified as deficiencies in the walkdown spreadsheet. NEI 12-07, Section 5.5.2, "Incorporated or Exterior Passive Flood Protection Features," requires verifying condition of the credited portion of the seal, in this case the licensee credited the inside seal for external flood protection.
During the audit team's site familiarization tour, NRC staff observed several outside watertight doors that are normally open. This practice exposes the seals to the environment, thereby potentially degrading seals more rapidly than normally closed watertight doors. This degradation may impact the flood sealing capability of these doors and therefore may require an increased preventative maintenance frequency.
While reviewing the licensee's flood protection procedures that were implemented during Hurricane Sandy and were common to both sites (i.e., OP-AA-108-11-1001, Revision 7, "Severe Weather and Natural Disaster Guidelines"), the NRC staff noted inconsistencies in the documentation of the implementation of the procedures between the sites.
The observations listed above were forwarded to the site resident inspectors for additional action.
- 5.
Potential Additional Information Needs In response to the observations described in Section 4.1 of this audit summary and to support the staff assessments of the licensee walkdown reports, the NRC staff may require additional information from the licensee regarding the methodology used to evaluate APM and responses to Question 27 for the walkdown record form in Appendix B of NEI 12-07 for flood protection features with small or zero APM. In addition, the staff may require additional information regarding the flood heights used to calculate the APM for certain flood protection features.
Moreover, the NRC staff may require additional information to clarify whether deficiencies were identified during the site walkdowns. Section 5.9, "Documenting Possible Deficiencies," of NEI 12-07, states that all flooding observations identified as deficiencies by the licensees CAP (and other items identified during the walkdowns but awaiting final disposition by the CAP) must be reported to the NRC as part of the licensee's walkdown report. Attachments A and D of the Salem Walkdown Report dated November 20, 2012, identify and describe potential deficiencies.
- 6.
Conclusions The audit provided NRC staff and contractors with information that is relevant to the staff assessment of the licensee's walkdown report. Observations made during the audit were communicated with the licensee and those deemed to be outside the scope of the audit were transferred to the Resident Inspector. In order to complete the staff assessment of the licensee's walkdown report, the NRC staff may require additional information. This audit summary will be used as an input to the staff assessment.
If you have any questions, please contact Mr. John Hughey at 301-415-3204 or by e-mail at john. hughey@nrc.gov.
Sincerely, Ira/
John D. Hughey, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Regulation Office of Nuclear Reactor Regulation Docket Nos. 50-272 and 50-311
Enclosure:
Audit Report cc w/encl: Distribution via Listserv DISTRIBUTION:
PUBLIC LPLI-2 R/F RidsNroDsea RidsNrrDorl Resource RidsRgn1 MaiiCenter Resource RidsOpaMail Resource RidsNrrLAABaxter Resource RidsNrrPMHopeCreek Resource NChokshi, NRR/DSEA EQuinones, EDO Rl, Rll, Rill, RIV RidsAcrsAcnw MaiiCTR Resource RidsNrrDoriLpii-2Resource ADAMS Accession Number: ML13308C286
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