IR 05000266/2013011
| ML13169A212 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 06/18/2013 |
| From: | Reynolds S Division Reactor Projects III |
| To: | Meyer L Point Beach |
| References | |
| EA-13-125 IR-13-011 | |
| Download: ML13169A212 (17) | |
Text
une 18, 2013
SUBJECT:
POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 NRC INTEGRATED INSPECTION REPORT 05000266/2013011 AND 05000301/2013011, PRELIMINARY YELLOW FINDING
Dear Mr. Meyer:
This letter refers to the inspection conducted from April 4, 2013 through June 6, 2013 for your Point Beach Nuclear Plant. The purpose of the inspection was to follow-up on issues identified during completion of Temporary Instruction (TI) 2515/187, Inspection of Near-Term Task Force Recommendation 2.3 Flooding Walk Downs. The issues were classified as a finding for the licensees lack of procedural requirements to appropriately implement external flooding wave run-up protection design features as described in the Final Safety Analysis Report. The finding was classified as an apparent violation with significance to be determined and was documented in NRC Inspection Report 05000266/2013002 and 05000301/2013002 (ML13133A356). The enclosed report documents the results of the follow-up efforts of this inspection, which were discussed on June 6, 2013, with you.
Based on the results of this inspection, the NRC has preliminarily determined the finding to be a Yellow finding with substantial safety significance that will result in additional NRC inspections and potentially other NRC action. As described in Section 4OA5, the inspection-identified finding involved the licensees lack of procedural requirements to appropriately implement external flooding wave run-up protection design features as described in the Final Safety Analysis Report. Specifically, the licensees procedure, as implemented, would not have protected safety-related equipment in the turbine building or pumphouse.
The finding does not present an immediate safety concern because the licensee has taken corrective action and revised the procedure to implement the wave run-up protection features.
Specifically, the licensees procedure has been revised to direct the installation of jersey barriers in conjunction with the use of sandbags, existing jersey barriers have been modified, and sandbags and additional jersey barriers have been purchased and pre-staged. This finding was assessed based on the best available information, using the applicable significance determination process (SDP). The basis for the NRCs preliminary significance determination is described in the enclosed report. This finding is also an apparent violation of NRC requirements and is being considered for escalated enforcement action in accordance with the NRC Enforcement Policy. The current Enforcement Policy is included on the NRCs Web site at http://www.nrc.gov/about-nrc/regulatory/enforcement/enforce-pol.html.
In accordance with NRC Inspection Manual Chapter (IMC) 0609, we intend to complete our evaluation using the best available information and issue our final determination of safety significance within 60 days of the date of this letter. The significance determination process encourages an open dialogue between the NRC staff and the licensee; however, the dialogue should not impact the timeliness of the staffs final determination. Before we make a final decision on this matter, we are providing you with an opportunity (1) to attend a Regulatory Conference where you can present to the NRC your perspective on the facts and assumptions the NRC used to arrive at the finding and assess its significance, or (2) submit your position on the finding to the NRC in writing. If you request a Regulatory Conference, it should be held within 30 days of the receipt of this letter and we encourage you to submit supporting documentation at least one week prior to the conference in an effort to make the conference more efficient and effective. If a Regulatory Conference is held, it will be open for public observation. If you decide to submit only a written response, such submittal should be sent to the NRC within 30 days of your receipt of this letter. If you decline to request a Regulatory Conference or submit a written response, you relinquish your right to appeal the final Significance Determination Process determination, in that by not doing either, you fail to meet the appeal requirements stated in the Prerequisite and Limitation sections of Attachment 2 of Inspection Manual Chapter 0609.
Please contact Mr. Jamnes Cameron at 630-829-9833 and in writing within 10 days from the issue date of this letter to notify the NRC of your intentions. With this notification you are requested to provide a list of equipment that is impacted by the flood levels of interest (wave run-up from 592 to 596 feet mean sea level (MSL), impounding up to 2 feet of water at the turbine building grade level), the basis for the list of equipment, and a discussion of any differences between assumed flood impacts documented in the Individual Plant Examination of External Events (IPEEE), the internal flooding Probabilistic Risk Assessment (PRA) notebook, and the Flooding Vulnerability Report, dated October 26, 2012. This information will allow us to refine our current significance determination. If we have not heard from you within 10 days, we will continue with and finalize our significance determination and enforcement decision. The final resolution of this matter will be conveyed in separate correspondence.
Because the NRC has not made a final determination in this matter, no Notice of Violation is being issued for the inspection finding at this time. In addition, please be advised that the number and characterization of the apparent violation described in the enclosed inspection report may change as a result of further NRC review. In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter, its enclosure, and your response (if any) will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records System (PARS)
component of NRC's Agencywide Document Access and Management System (ADAMS).
ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Sincerely,
/RA/
Steven A. Reynolds, Director Division of Reactor Projects Docket Nos. 50-266; 50-301 License Nos. DPR-24; DPR-27
Enclosure:
Inspection Report 05000266/2013011 and 05000301/2013011 w/Attachment: Supplemental Information
REGION III==
Docket Nos: 50-266, 50-301 License Nos: DPR-24, DPR-27 Report No: 05000266/2013011; 050000301/2013011 Licensee: NextEra Energy Point Beach, LLC Facility: Point Beach Nuclear Plant Location: Two Rivers, WI Dates: April 4, 2013 through June 6, 2013 Inspectors: S. Burton, Senior Resident Inspector D. Betancourt, Acting Senior Resident Inspector M. Thorpe-Kavanaugh, Resident Inspector L. Kozak, Senior Reactor Analyst Approved by: J. Cameron, Branch Chief Branch 6 Division of Reactor Projects
SUMMARY OF FINDINGS
IR 05000266/2013011; 050000301/2013011; 04/03/2013 - 06/06/2013; Point Beach Nuclear
Plant, Flood Protection This report covers the circumstance behind the failure to establish a procedure to implement external flooding wave run-up design features. The NRC staff identified one finding, preliminarily determined to be
- Yellow.
The preliminary Yellow finding is associated with a violation of NRC requirements. The significance of inspection findings is indicated by their color (i.e., greater than Green, or Green, White, Yellow, Red) and determined using Inspection Manual Chapter (IMC) 0609, Significance Determination Process, dated June 2, 2011. The cross-cutting aspect is determined using IMC 0310, Components Within the Cross-Cutting Areas, dated October 28, 2011. All violations of NRC requirements are dispositioned in accordance with the NRC's Enforcement Policy dated January 28, 2013. The NRC's program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, "Reactor Oversight Process," Revision 4, dated December 2006.
NRC-Identified
and Self-Revealed Findings
Cornerstone: Mitigating Systems
- Preliminary Yellow: A finding and an apparent violation of 10 CFR Part 50, Appendix B,
Criterion V, Instructions, Procedures, and Drawings, was identified by the inspectors in that from January 19, 1996 until March 13, 2013, the licensee failed to have a procedure appropriate to the circumstances to address external flooding as described in the Final Safety Analysis Report (FSAR.) Specifically, Procedure PC 80 Part 7, as implemented, would not protect safety-related equipment in the turbine building or pumphouse because the procedure (1) did not appropriately prescribe the installation of barriers such that gaps in or between the barriers were eliminated to prevent water intrusion, (2) did not protect equipment by requiring barriers to be placed in front of the doors, from 1996 to 2008, as described in the FSAR, and (3) did not require the barriers to protect the plant to an elevation of at least 9 feet (589 foot elevation) as described in the FSAR.
The performance deficiency was screened against the Reactor Oversight Process per the guidance of lMC 0612, Appendix B, and determined to be more than minor because the finding was associated with the Mitigating Systems Cornerstone attributes of Protection Against External Factors (Flood Hazard) and Procedure Quality, and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences (i.e. core damage). Specifically, the licensees failure to procedurally control and maintain external flooding design features and to provide procedural controls for external events could negatively impact mitigating systems ability to respond to an external flooding event. The inspectors evaluated the finding using IMC 0609,
Attachment 0609.04, Tables 2 and 3, and Appendix A, and determined a detailed risk evaluation was needed. This finding does not present an immediate safety concern, in that, the licensee has taken corrective action and revised procedures implementing wave run-up protection features. Specifically, the licensees procedure has been revised to direct the installation of jersey barriers in conjunction with the use of sandbags, existing jersey barriers have been modified, and sandbags and additional jersey barriers have been purchased and pre-staged. These issues are being characterized as an apparent violation in accordance with the NRC's Enforcement Policy, with its final significance to be dispositioned in separate future correspondence. This finding has a cross-cutting aspect in the area of problem identification and resolution, corrective action program, because the licensee failed to thoroughly evaluate problems such that the resolutions address causes and extent of conditions P.1(c). (Section 4OA5)
B. Licensee-Identified Violation None
REPORT DETAILS
OTHER ACTIVITIES
Cornerstones: Mitigating Systems
4OA5 Other Activities
.1 Failure to Establish an Adequate Procedure to Implement External Flooding Wave Run-
Up Design Features
a. Inspection Scope
The inspectors and the Senior Reactor Analyst (SRA) completed their inspection and assessment of a finding classified as an apparent violation with significance to be determined that was previously documented in NRC Inspection Report 05000266/2013002 and 05000301/2013002 (ML13133A356). The inspection and assessment included the review of procedures and information to preliminarily determine the significance of the finding and apparent violation.
b. Introduction A finding of potential substantial safety significance (Preliminary Yellow) and an apparent violation of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, was identified by the inspectors in that from January 19, 1996 until March 13, 2013, the licensee did not have a procedure that provided for Final Safety Analysis Report (FSAR) design criteria for external flooding wave run-up protection.
Specifically, the licensees procedure, as implemented, would not protect safety-related equipment in the turbine building or pumphouse.
Description The description of the finding was documented in NRC Inspection Report 05000266/2013002 and 05000301/2013002 (ML13133A356) and is reproduced here for convenience.
As an extent of condition review from URI 05000266/2012002 01; 05000301/2012002 01, and in response to TI-187, the inspectors reviewed the licensing basis information and found that the FSAR described external flooding design features and mitigating strategies to protect against a wave run-up flooding event. This flooding event is postulated to occur when waves from Lake Michigan break over the bank entering the circulating water pumphouse and turbine buildings through existing non-watertight doors in each structure. The FSAR states that the site would protect the turbine building and pumphouse by using sandbags, concrete jersey barriers, or equivalent barriers placed on the north and south sides of the circulating water pumphouse just to the west of the walkway.
Licensee procedure PC 80 Part 7, Lake Water Level Determination, implemented these features as described in the FSAR. The inspectors reviewed PC 80 Part 7 and found that guidance was only provided for installation of concrete jersey barriers.
The licensee performed a walkthrough of the sites flooding procedure in response to the NRCs 50.54(f) Near-Term Task Force Review of Insights from the Fukushima Dai-Ichi Accident, letter which requested flood area walkdowns and procedure walkthroughs. During the performance of TI-187, the inspectors reviewed the licensees Wave Run-Up Mitigation Package and observed the PC 80 Part 7 walkthrough. During the walkthrough, the licensee discovered that the jersey barriers could not be installed as described in the procedure.
Specifically, that the area where the jersey barriers were to be installed was not a hardened flat surface; therefore, when the jersey barriers were installed, the barriers were not flush with the ground, and a 4-inch gap was created, which allowed water intrusion past the barriers. The licensee also discovered that the jersey barriers could not be installed against one another due to the existence of rebar at either end of the barriers. This created a gap between each barrier that allowed water intrusion between each of the barriers. Also, the bottom of the jersey barriers were cut to allow them to be moved by use of a forklift creating holes in the bottom of each barrier that allowed water intrusion past the barriers.
Additionally, the length of the barriers was insufficient to provide protection as needed. An additional 8.42-foot jersey barrier on each side of the pumphouse would need to be installed beyond what was previously identified to provide the needed protection against wave run-up. Finally, the barriers were to be installed in areas that were identified as B.5.b equipment staging areas and consideration of the design interfaces was not assessed. The licensee entered the identified deficiencies into the CAP as AR01809095, AR01824582, AR01807841, and AR01806402.
Although the licensee identified this issue described above in response to the NRCs 50.54(f) letter, the inspectors found that the licensee did not assign prompt corrective actions to fix the deficient barriers until prompted by inspectors; the licensee did not consider the amount of time needed to erect the barriers until prompted by inspectors; and the licensee did not recognize the need to perform additional evaluations for crediting the use of sandbags and jersey barriers until prompted by inspectors. The licensee documented these concerns in AR01853775, AR01853779, and AR01849522, as well as updated the above-listed CRs and corrective actions due dates to ensure the wave run-up design features were fully evaluated. Therefore, this finding will be characterized as NRC identified because the inspectors added value in the identification of previously unknown weakness in the licensees initial classification, evaluation, and corrective actions associated with this issue.
The licensee initiated AR01856327 in response to the inspectors concerns.
Analysis The initial analyses of the finding were documented in NRC Inspection Report 05000266/2013002 and 05000301/2013002 (ML13133A356) and are reproduced here for convenience. The additional analyses performed are documented after the reproduced sections.
The inspectors determined that the licensees failure to establish appropriate procedural requirements to implement external flooding wave run-up protection design features as described in the FSAR was a performance deficiency warranting further evaluation.
The inspectors determined that this finding was more than minor in accordance with IMC 0612, Appendix B, because the finding was associated with the Mitigating Systems Cornerstone attributes of Protection Against External Factors (Flood Hazard) and Procedure Quality, and adversely affected the Cornerstone objective to ensure the availability reliability, and capability of systems that respond to initiating events to prevent undesirable consequences (i.e. core damage). Specifically, the licensees failure to procedurally control and maintain external flooding design features, and provide appropriate procedure directions for responses to external events, could negatively impact mitigating systems ability to respond to an external flooding event.
The inspectors evaluated the finding using IMC 0609, Attachment 0609.04, Tables 2 and 3, and Appendix A for the Mitigating Systems Cornerstone. The inspectors answered Yes to the Appendix A, Exhibit 2.B question for external event mitigating systems (Seismic/Fire/Flood/Severe Weather Protection Degraded), because it represented loss or degradation of equipment designed to mitigate a flooding event. Specifically, the jersey barriers were determined to not be of sufficient length to provide protection and allowed water intrusion past the barriers. The inspectors answered No to Exhibit 4, Question 1, because, if it is assumed the barrier was completely failed or unavailable, the loss of the barrier by itself during the event it was intended to mitigate, would not cause a plant trip or initiating event, would not degrade two or more trains, and would not degrade one train of a system that supports a risk significant system or function. The inspectors answered Yes to Exhibit 4, Question 2, because the finding involved the loss of any safety function identified by the licensee through IPEEE analysis.
Specifically, the licensees IPEEE credits sandbags to protect against external flooding events. Since the licensee substituted the use of jersey barriers in place of sandbags, the jersey barriers were determined to not be able perform the safety function as described. Therefore, the inspectors determined that a detailed risk evaluation was needed.
The RIII SRA performed a preliminary detailed risk evaluation using the external flooding baseline risk evaluation from the licensees Individual Plant Examination of External Events (IPEEE), dated June 30, 1995. The SRA also considered additional risk information provided by the licensee PRA staff in a document titled, Point Beach External Flood Safety Significance Determination dated April 26, 2013. The preliminary change in core damage frequency (CDF) was estimated to be 1.8E-5, which is a finding of substantial safety significance (Yellow).
The FSAR described flood protection measures to protect the plant to the 589 foot elevation which provided for a small margin from the design basis wave run-up event of 588.62 foot elevation. In the IPEEE, the licensee evaluated the risk of external flooding due to high still water lake level plus wave run-up. The IPEEE credited the use of sandbags built to the 589 foot elevation which is a height of one foot around the turbine building grade level and two feet around the circulating water pumphouse. The IPEEE further assumed that flooding in the buildings would occur if the sandbags were overtopped by wave run-up by one foot.
The sandbagging method of flood protection was replaced in 1996 by a method using concrete jersey barriers. To model the performance deficiency, the SRA assumed that no flood protection was installed (i.e., no sandbags, jersey barriers, or equivalent installed). The baseline risk was estimated using the IPEEE information which credited sandbag protection. The CDF was estimated by calculating the risk of external flooding with no flood protection and subtracting the baseline risk.
The IPEEE analysis assumed that to fail safety-related equipment in the plant, 6 to 12 inches of water must accumulate above plant grade in between the circulating water pumphouse and the turbine building. Plant grade was assumed to be 588.2 ft. One foot of water was assumed to accumulate for a wave run-up event to the 592 ft. elevation and two feet of water was assumed to be impounded for a wave run-up event to 596 ft.
elevation. With this information, the SRA determined that the sandbagging method provided some protection for a wave run-up event between 592 ft. and 596 ft. This was the range of wave run-up events used in the preliminary detailed risk analysis. The IPEEE analysis further assumed that the sandbags must be overtopped by 1 ft. of water to result in flooding necessary to fail safety-related equipment. Table 5.2.7-1 of the IPEEE lists the critical equipment assumed to be rendered unavailable if the buildings are flooded, The licensee derived the flood frequencies for various wave run-up levels from the IPEEE and documented this in their safety significance determination. The SRA used these values in the preliminary detailed risk evaluation. The frequency of a wave run-up event exceeding 592 ft. was estimated to be 7.3E-4/yr. For the baseline risk estimate, the SRA assumed that the sandbagging method of protection had a failure probability of 0.1. If sandbagging failed, water would enter the turbine building, control building and circulating water pumphouse and impact plant equipment. For the performance deficiency risk estimate, the flood protection features were assumed to be failed.
The SRA assumed that the wave run-up event was concurrent with a weather-related loss of offsite power (LOOP) event. The flood itself does not cause the LOOP to occur; it is assumed that the wind and weather necessary to cause the wave run-up also causes a LOOP. The SRA used a modified version of the current Point Beach Standardized Plant Assessment Risk model to estimate a conditional core damage probability (CCDP) assuming a weather-related LOOP occurs and the flood impacts mitigating equipment in the turbine building, control building, and the circulating water pumphouse. To calculate the CCDP, the SRA used the list of equipment impacted by the flood as defined by the licensee in their safety significance determination. The SRA determined through discussion with the licensee PRA staff that the source of the list of equipment impacted was a recently issued Internal Flooding PRA notebook. The SRA calculated a CCDP of 2.7E-2. Using this CCDP and the other inputs described above results in a CDF result of 1.8E-5/yr, which is a finding of substantial safety significance (Preliminary Yellow). The dominant sequence was a wave run-up flood event with a concurrent weather-related LOOP, followed by the failure of auxiliary feedwater and the failure of feed and bleed. The failure of auxiliary feedwater is in part due to flood effects and in part due to random failures of other equipment or operator actions necessary to maintain a long term auxiliary feedwater suction source.
To complete the final significance determination, the NRC has determined that additional review of the flood effects on equipment is necessary because several sources of relevant information reviewed contained conflicting information regarding the vulnerability of plant components to internal building water levels. Specifically, the NRC plans to perform additional reviews of available plant information on the impact of flooding in the turbine building, control building, and circulating water pumphouse.
Enforcement:
A preliminary safety significant (Yellow) finding and an apparent violation of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, was identified by the inspectors in that from January 19, 1996 until March 13, 2013, the licensee failed to have a procedure appropriate to the circumstances to address flooding as described in the FSAR. Specifically, procedure PC 80 Part 7, as implemented, would not protect safety-related equipment in the turbine building or pumphouse because the procedure
- (1) did not appropriately prescribe the installation of barriers such that gaps in or between the barriers were eliminated to prevent water intrusion,
- (2) did not protect equipment by requiring barriers to be placed in front of the doors, from1996 to 2008, as described in the FSAR, and
- (3) did not require the the barriers to protect the plant to an elevation of at least 9 feet (589 foot elevation elevation) as described in the FSAR.
The licensee entered this issue into the CAP as AR01856327. Completed corrective actions include: procedure revision; installation of jersey barriers in conjunction with the use of sandbags; modified existing jersey barriers; and, sandbags and additional jersey barriers have been purchased and pre-staged. This is being characterized as an AV in accordance with the NRC's Enforcement Policy, and its final significance will be dispositioned in separate future correspondence (AV 05000266/2013002-10; 05000301/2013002-10, Failure to Establish A Procedure to Implement Wave Run-Up Design Features).)
4OA6 Management Meetings
.1 Exit Meeting Summary
On June 6, 2013, the inspection results were presented to Mr. L. Meyer. The licensee acknowledged the issues presented. None of the potential report input discussed was considered proprietary.
4OA7 Licensee-Identified Violations
None.
ATTACHMENT:
SUPPLEMENTAL INFORMATION
KEY POINTS OF CONTACT
Licensee
- L. Meyer, Site Vice President
Ron Seizert, Licensing Supervisor
Anil Julka, PRA Engineer, NextEra Energy
Jon Leiker, PRA Engineer, Point Beach
Nuclear Regulatory Commission
- J. Cameron, Branch Chief
Attachment
LIST OF ITEMS
OPENED, CLOSED AND DISCUSSED
Discussed
- 05000266/2013002-10; AV Failure to Establish A Procedure to Implement Wave Run-Up
- 05000301/2013002-10 Design Features