IR 05000443/2002011

IR 05000443-02-011, on 09/16-10/04/02; Seabrook Station; Biennial Inspection of the Identification and Resolution of Problems

ML023180728
Person / Time
Site:	Seabrook
Issue date:	11/14/2002
From:	David Lew NRC/RGN-I/DRS/PEB
To:	Peschel J, Warner M Florida Power & Light Energy Seabrook
References
IR-02-011
Download: ML023180728 (15)

Text

ber 14, 2002

SUBJECT:

SEABROOK STATION - NRC PROBLEM IDENTIFICATION & RESOLUTION INSPECTION REPORT NO. 50-443/02-011

Dear Mr. Warner:

On October 4, 2002, the NRC completed the biennial problem identification and resolution team inspection at your Seabrook Station. The enclosed report documents the inspection findings which were discussed at an exit meeting on October 4, 2002, with Mr. G. St. Pierre and other members of the Seabrook Station staff.

The inspection was an examination of activities conducted under your license as they relate to the identification and resolution of problems, and compliance with the Commissions rules and regulations, and the conditions of your operating license. Within these areas, the inspection involved examination of selected procedures and representative records, observations of activities, and interviews with personnel.

On the basis of the sample selected for review, the corrective action program at Seabrook was adequate. Overall your staff identified problems at an appropriate threshold, conducted proper evaluations, and implemented appropriate corrective actions.

One Green finding was identified during the inspection regarding inadequate calculations used to determine the acceptability of voids in the suction piping to safety-related pumps. This Green finding was determined to be a violation of NRC requirements. However, because of its very low safety significance and because it is being addressed within your corrective action process, the NRC is treating this as a non-cited violation, in accordance with Section VI.A.1 of the NRCs Enforcement Policy. If you deny this non-cited violations, you should provide a response with the basis for your denial, within 30 days of the date of this inspection report, to the Nuclear Regulatory Commission, ATTN.: Document Control Desk, Region I; the Director, Office of Enforcement, United States Nuclear Regulatory Commission, Washington, D.C.

20555-0001; and the NRC Resident Inspector at the Seabrook facility.

Mr. Ted C. Feigenbaum 2 In accordance with 10 CFR 2.790 of the NRCs "Rules of Practice," a copy of this letter and its enclosure will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records (PARS) component of NRCs document 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/

David C. Lew, Chief Performance Evaluation Branch Division of Reactor Safety Docket No. 50-443 License No. NPF-86

Enclosure:

NRC Inspection Report 50-443/02-011

REGION I==

Docket No: 50-443 License No: NPF-86 Report No: 50-443/02-011 Licensee: FPL Energy Seabrook Facility: Seabrook Station Location: P.O. Box 300 Seabrook, NH 03874 Dates: September 16 - October 4, 2002 Inspectors: W. Schmidt, Sr. Reactor Inspector, DRS M. Gray, Sr. Reactor Inspector, DRS D. Schroeder, Reactor Inspector, DRS C. Jones, contractor Approved By: David C. Lew, Chief Performance Evaluation Branch Division of Reactor Safety

SUMMARY OF FINDINGS

IR 05000443/02-011; 9/16-10/4/02; Seabrook Station; biennial inspection of the identification and resolution of problems.

The inspection was conducted by two regional inspectors and one contractor. The team identified one Green finding of very low safety significance during the inspection and classified it as a non-cited violation. The significance of most findings is indicated by their color (green, white, yellow, red) using Inspection Manual Chapter 0609, Significance Determination Process (SDP). Findings for which the SDP does not apply may be green or be assigned a severity level after NRC management review. The NRCs program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process,

Revision 3, dated July 2000.

Identification and Resolution of Problems Overall, the team concluded that the licensee identified problems at an appropriate threshold, conducted proper evaluations, and implemented appropriate corrective actions within the corrective action program (CAP). The daily condition review team meeting provided good coordination and review of issues entered into the system. Operability determinations and extent of condition reviews were appropriate. CAP performance indicators, audits, self-assessments, and cause code trending provided good information on program performance, areas for improvement, and potential trends. Corrective actions were effective and properly documented including resource intensive projects such as modifications.

Cornerstone: Mitigating Systems

Green.

A non-cited violation of 10 CFR Appendix B, Criterion III, Design Control, for failure to identify calculation errors regarding air void acceptance criteria for emergency core cooling piping.

The calculation errors resulted in an incorrect conclusion that air voids in charging and safety injection pump suction piping high points would not likely be entrained in system flow. This issue was more than minor because the incorrect conclusion could reasonably be viewed as a precursor to a more significant event affecting the mitigating systems cornerstone. Specifically, the void limits were based on engineering judgement rather than a technical assessment of charging and safety injection pump performance with void entrainment in the system flow.

However, the issue was determined to have very low safety significance in accordance with Phase I of the SDP. The availability of the pumps was never affected because the procedural acceptance criteria limited the detectable air void volumes to a point that performance would not have been degraded. (Section 4OA2.b).

ii

REPORT DETAILS

4OA2 Problem Identification and Resolution

a.

Effectiveness of Problem Identification

(1) Inspection Scope The team reviewed the Seabrook corrective action program (CAP); items entered into this process are referred to as condition reports (CRs). The team reviewed CRs and other documents, identified in Attachment 1, to determine the licensees threshold for identifying problems and entering them into the CAP.

The team reviewed items from the licensees operating, maintenance, quality assurance (QA)audit, and departmental self-assessment processes to determine if personnel initiated CRs after identifying problems. The team also reviewed a sample of work requests (WR), system health reports, surveillance test (ST) results, and operating experience information.

The team attended the licensees daily condition review team (CRT) meeting to assess the type of issues identified during the inspection. The team also conducted a plant walk-down of safety-related, risk significant areas to verify that observable system equipment and plant material adverse conditions were entered into the CAP. Additionally, the team interviewed plant personnel to discuss technical issues and the use of the CAP.

(2) Findings Overall the team concluded the licensee identified problems at an appropriate threshold and entering them into the CAP for resolution. The identification of repetitive trends appeared proper. Reviews of equipment condition during plant tours did not identify any adverse conditions that were not previously identified. People interviewed appeared to understand the expectations for initiating CRs. Licensee audits and self-assessments were comprehensive and were effective. Also, the team did not identify any conditions adverse to quality being handled outside the CAP.

b.

Prioritization and Evaluation of Issues

(1) Inspection Scope The CR process required that each issue be assigned a significance level; level A, the most significant, receive a root cause determination; level B receive an apparent cause determination; and level C, the least significant, require only correcting the condition, without a specific causal analysis. The program considers level A, B, and C CRs to be conditions adverse to quality relative to 10 CFR 50, Appendix B, Criterion XVI. The program has a fourth significance level, level D, which is used to document conditions that are not adverse to quality.

The team screened CRs issued since the previous problem identification and resolution inspection and selected those listed in Attachment 1 of this report for detailed review to determine whether the issues were properly evaluated and resolved. The sampled CRs included issues in risk significant systems including: auxiliary feed water (AFW), service water (SW), instrument air, alternating current (AC) and direct current (DC) electrical systems, and several issues related to non-cited violations (NCVs) and Licensee Event Reports (LERs). For the selected CRs, the team reviewed the licensee reportability and operability determination (OD); the assignment of significance and priority; and the technical adequacy, scope, and depth of the root or apparent cause evaluation.

In addition to reviewing more than 200 selected CRs, the team attended several of the daily CRT meetings and interviewed engineers and managers responsible for assigning significance levels, prioritizing, and conducting evaluations. The team also attended a joint corrective action review board (CARB) and management review team (MRT) meeting where the root cause assessment for a level A CR concerning a security guard performance issue was discussed.

(2) Findings The team found that issues were properly prioritized and evaluated. The CRT provided good coordination and review of the day-to-day input to the CAP. The CRT was cognizant of recurring issues and trends. The MRT and CARB provided appropriate oversight. CAP performance indicator appeared to be providing good information on program performance and areas for improvement. The team noted that the backlog of open corrective actions was reduced over the last year. Cause code trending was in use and appeared effective, along with audits and self-assessments, at identifying areas for improvement. Extent of condition reviews were appropriate. The team reviewed several ODs and did not identify any issues.

The team identified one finding and several minor issues concerning evaluations and prioritizations. The finding, discussed below, concerned an inadequate engineering calculation leading to an incorrect evaluation of potential pipe voiding in safety-related piping. The team discussed several minor issues with licensee management, including: an improper significance level characterization for a repeated loose parts monitor alarm during feedwater isolation valve testing; CRs that were closed to lower level CR actions without clear transfer of action responsibility; and examples where evaluations could have been more complete.

Green. A non-cited violation of 10 CFR Appendix B, Criterion III, Design Control, for failure to identify calculation errors regarding air void acceptance criteria for emergency core cooling system (ECCS) piping.

The inspectors reviewed significance level D CR 02-12558, initiated in August 2002, which identified a small air void in an eight inch diameter pipe segment from the outlet of the reactor water storage tank to the A charging pump inlet. The void was detected, using ultrasonic testing, during routine technical specification (TS) required ST to ensure that ECCS system piping is full. The CR indicated the void did not present an operability concern since the size was less than the procedural acceptance criteria, and the CR was closed to trending.

The inspectors reviewed the acceptance criteria contained in ST OX1456.02, and the supporting calculation C-S-1-84104, developed and implemented based on industry experience in 1999. The calculation addressed five high points in charging and safety injection pump suction piping that could not be vented. The calculation used the non-dimensional fluid hydraulic Froude number to characterize whether an air void would likely be entrained and carried to the suction of a safety-related pump. For safety injection and charging pump suction piping, the calculation presented a relatively low Froude number and concluded that a void would not likely be drawn as an air pocket into the downstream pumps. However, based on engineering judgement, the ST limited the voids in these piping high points to 25% of the cross section of the piping.

In reviewing the calculation the inspectors identified errors including use of inappropriate units for pipe diameter and incorrect assumptions for pipe area, based on the reduction of available pipe area due to the void. Both of these errors would increase the calculated Froude numbers and increase the potential that a void would be entrained and pass though a safety-related pump. In response to inspector questions, Seabrook personnel initiated CR 02-14102, re-calculated the Froude numbers, and concluded that air voids in the charging pump and safety injection suction piping high points would likely be swept into the downstream pumps.

The licensee then evaluated the possible volume of an air void that could be present based on the ST acceptance criteria of 25% of the pipe cross section, determining that pump performance would not have been degraded. Seabrook personnel indicated they planned to revise the calculation to indicate air voids would likely be swept along with system flow.

Additionally, they planned to revise ST OX1456.02 to provide void acceptance criteria in terms of pipe volume.

The inspectors reviewed published pump voiding limits and similar analyses and tests performed by other licensees, and concluded the procedural void limits had been sufficient to reasonably ensure pump performance would not be degraded by air voids. The issue, however, was more than minor since the calculation errors resulted in an incorrect conclusion that air voids in charging and safety injection pump suction piping high points would not likely be entrained in system flow. This incorrect conclusion could reasonably be viewed as a precursor to a more significant event since the void limits were based on engineering judgement rather than a technical assessment of charging and safety injection pump performance with void entrainment in the system flow. The issue affected the mitigating systems cornerstone because the charging and safety injection pumps provide high and intermediate pressure injection flow for core cooling during postulated accident conditions. The issue was determined to have very low safety significance using Phase I of the NRC significance determination process described in NRC IMC 0609, Appendix A, because, notwithstanding the calculation errors, the procedural acceptance criteria adequately limited detectable air pocket volumes to ensure that pump performance would not be degraded.

Therefore the charging and safety injection systems remained operable and the issue does not represent an actual loss of system function.

10 CFR Appendix B, Criterion III, Design Control, requires, in part, that design control measures shall provide for verifying or checking the adequacy of design, including hydraulic analyses. Contrary to this requirement, in December 1999, design control measures did not ensure the adequacy of Calculation C-S-1-84104, Revision 0, calculation errors led to incorrect conclusions regarding the likelihood of air void entrainment in charging system pipe flow.

However, because of the very low safety significance of this issue and because it was entered into the CAP as CR 02-14102, the issue is being treated as a non-cited violation, consistent with Section VI.A.1 of the NRC Enforcement Policy. (NCV 50-443/02-11-01)c.

Effectiveness of Corrective Actions

(1) Inspection Scope The team reviewed the corrective actions associated with selected CRs to determine whether the identified causes were appropriately addressed and completed or scheduled to be completed in a timely fashion. The team reviewed CRs for repetitive problems to determine the effectiveness of previous corrective actions. In addition the team reviewed the Equipment Reliability Budget Committee (EBRC), which is responsible for prioritizing and dispositioning long-term corrective actions, such as plant modifications. This included reviewing evaluation and prioritization listing and a sample of project summary description and interviewing the EBRC chairman.

(2) Findings The team found that corrective actions were effective and properly documented within the CR system. The effectiveness reviews and audits selected were appropriate, including several where the reviewers identified and took actions to correct inadequate corrective actions. The inspection team determined that the corrective actions for resource intensive projects such as modifications were adequate and timely.

d.

Assessment of Safety Conscious Work Environment

(1) Inspection Scope During the inspection, the team interviewed plant staff to determine if conditions existed at the site which would result in personnel being hesitant to raise safety concerns to Seabrook management and/or the NRC.

(2) Findings No findings of significance were identified.

e.

Selected Issue Follow-up

(1) Inspection Scope A team member conducted a detailed review of Limitorque valve actuator issues in accordance with the guidance provided for sample inspections in IP 71152. The inspector reviewed licensee corrective actions for two Limitorque MOV failures. In one instance, SW-V-74 failed to close, and SW-V-76 failed to open, both used SMB-0 actuators. CR 02-08565 identified concerns that actuator spring packs were incorrectly assembled during valve actuators modifications. The associated Apparent Cause Evaluation identified that incorrect assembly allowed the bearing cartridge cap to unthread from the bearing cartridge stem. Misalignment of these components caused premature actuation of the torque switch and prevented further movement of the valve. The unthreading of the cartridge cap was apparently caused by not properly using Loctite on the threads during reassembly following modification DCR 97-021.

The apparent cause determination was reviewed to ensure that the full extent of the issues was identified, that appropriate evaluations were performed, and that appropriate corrective actions were specified and prioritized. The inspector also reviewed selected work orders (WOs), and procedure changes and performed a system walk down to ensure that proper corrective maintenance had been completed. CRs for other Limitorque actuators were reviewed to identify additional valve actuator problems. The training facility was toured and appropriate people were interviewed for additional insight into the problem.

The inspector reviewed the extent of condition analysis performed by the licensee, after detection of the potential common mode failure in the two SMB-O actuators. Maintenance and Plant Engineers developed a list of valves that could experience a similar failure. Valve sizes other than SMB-0 do not use Loctite for spring pack assembly. The licensee inspected all size SMB-0 MOVs in the service water (SW) system, finding no similar problems. The inspector reviewed actions taken to prevent reoccurrence. Maintenance Procedure LS 0569.02 was changed to identify the application of Loctite as a critical step, and to add a place-keeping box to this step. The licensee also improved the Loctite used on these components.

(2) Findings No findings of significance were identified.

The inspector found that the apparent cause evaluation, the extent of condition review, and the corrective actions following two service water valve failures were appropriate. The inspector found that there have been no additional failures of SMB-0 valve actuators and no other CRs with assembly related problems that affected MOV operability.

4OA6 Meetings, Including Exit

a.

Exit Meeting Summary

On October 4, 2002, the team presented the inspection results to Mr. G. St. Pierre and other members of Seabrook management at the conclusion of the inspection. The licensee acknowledged the issues and finding presented.

The inspectors asked the licensee whether any material examined during this inspection should be considered proprietary. No proprietary information was identified.

ATTACHMENT 1 -

SUPPLEMENTAL INFORMATION

KEY POINTS OF CONTACT

North Atlantic Energy Service Company

G. St. Pierre, Station Director

J. Peschel, Regulatory Programs Manager

V. Pascucci, assistant Oversight Manager

R. LeGrand, Work Control and Outage Manager

M. Lewis, Modifications and projects Manager

R. Hickok, NRC Coordinator

M. Carmichael, Performance Improvement Manager

C. Berry, Corrective Action and Human Performance Program Manager

R. Badge, Modifications Supervisor

B. Brown, Engineering Supervisor

R. Distefano, Maintenance Supervisor

J. Hill, Operations Engineering

E. Lent, Corrective Action/Lead CR Coordinator

E. Metcalf, Assistant Pant Engineering Manager

R. Parry, Engineering Supervisor

R. White, Nuclear Design Engineering Manager and Chairman ERBC

Nuclear Regulatory Commission

G. Dentel, Senior Resident inspector

J. Brand, Resident Inspector

ITEMS OPENED, CLOSED, AND DISCUSSED

Opened and Closed

05000443/2002-11-01 NCV Failure to perform an adequate calculation of ECCS pump suction piping void migration, because of mathematical and assumption errors.

LIST OF ACRONYMS USED CAP corrective action program CARB corrective action review board CR condition report CRT condition review team EBRC Equipment Reliability Budget Committee ECCS emergency core cooling system EDG Emergency Diesel Generator MRT management review team NAESCo North Atlantic Energy Service Company NCV non-cited violation NRC Nuclear Regulatory Commission OD operability determination QA Quality Assurance SDP Significance Determination Process ST surveillance test SW service water TS technical specifications