IR 05000285/1997009

Discusses Insp Rept 50-285/97-09 on 970423-0610 & Forwards Nov.Violation Involves Failure to Comply W/Conditions of 10CFR50.65 Plant Had Not Demonstrated That Condition of Sys Was Being Effectively Controlled Through Preventive Maint

ML20217J968
Person / Time
Site:	Fort Calhoun
Issue date:	08/11/1997
From:	Merschoff E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:	Gambhir S OMAHA PUBLIC POWER DISTRICT
Shared Package
ML20217J973	List: IR 05000285/1997009 ML20217J992
References
50-285-97-09, 50-285-97-9, EA-97-280, NUDOCS 9708150095
Download: ML20217J968 (5)

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NUCLEAR REGULATORY COMMISSION -

REoloN IV 611 RYAN PLAZA oRIVE, SulTE 400 ($, -

ARLINoTofJ, TEXAS 760114064 August _ 11, 1997 EA 97 280

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S. K. Gambhir, Division Manager Production Engineering -

Omaha Public Power District Fort Calhoun Station FC 2 4 Adm.

P.O. Box 399 Hwy. 75 - North of Fort Calhoun Fort Calhoun, Nebraska 68023-0399

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SUBJECT: NOTICE OF VIOLATION (NRC INSPECTION REPORT 50 285/97 09)

Dear Mr. Gambh!r:

This refers to the inspection conducted on April 23 through June 10,1997, at the Fort Calhoun Station reactor facility. The inspection focused on the causes, circumstances, and corrective actions associated with the April 21,1997, extraction steamline rupture at the Fort Calhoun Station. The inspection findings were discussed with you and your staff

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during an exit briefing on June 10,19f'7, and the findings were 'Jeumented in the subject inspection report dated June 17,1997. The inspection report identmd one apparent violation of the Maintenance Rule,10 CFR 50.65. Subsequently, a predecisional enforcement conference was conducted in the Region IV Arlington, Texas office on July 21,1997.

During the July 21 conference, your position was that, although you viewed the event as serious, it did not involve a violation of the maintenance rule. Your staff stated that:

(1) industry experience provided a basis for including the extraction steam system into the scope of the maintenance rule because it could cause a plant trip (this is a requirement per 10 CFR 50.05(b)(iiill (2) the system was appropriately classified as nonrisk significant (this is not a regulatory requirement only a recommendation ir' the regulatory guide and industry guideline documents); and (3) no problems had been detected in the extraction steam system during a review of a four-year period prior to July 1996 (problems that caused the reactor to scram or cause actuation of a safety related system...not pipe ruptures]. Further, your staff stated that no known large radius piping sweep failures had occurred. Your position was that the Fort Calhoun Station's decision to monitor the system under 10 CFR 50.65(a)(2) was reasonable given the information available. The decision to monitor the system under paragraph (a)(2) of the rule was reviewed and approved by your expert panel. _ Station management considered the erosion / corrosion j program effective as indicated by, among other indicators, proactive replacement of piping $'

prior to reaching minimum wall thickness. The April 21_ event'was the initial Maintenance Preventable Functional Failure, and so it was now (after the rupture) appropriate to- -

establish goals in accordance with 10 CFR 50.65(a)(1) for certain piping that is susceptible t to flow accelerated corrosion. k 9708150095 970811 PDR G

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Omaha Public Power District 2-We note that the maintenance rule was promulgated to require licensees to monitor the effectiveness of maintenance activities in order to minimize the likelihood of failures and events caused by the lack of effective maintenance. Where failures are likely to cause loss of intended function, monitoring should be predictive in nature, providing early warning of degradation. Erosion / corrosion programs are an essential element of preventive maintenance, which, if implemented properly, would give licensees ample information to identify degradation and to take effective corrective actions to prevent failures. This is achieved partly through performance and condition trending of plant structures, systems and components. Additionally, industry-wide operating experience must be addressed when maintenance programs are developed and implemented to assure that failures that have occurred elsewhere are not repeated. As required by the maintenance rule, industry-wide operating experience must be reviewed for plant specific applicability and, where appropriate, must be included in licensee programs and procedures.

The NRC's position in this case is that, in deciding to monitor the extraction steam system under paragraph (a)(2) of the rule, the Fort Calhoun Station had not first adequately demonstrated that the condition of this nonsafety related system was being effectively controlled through the performance of appropriate preventive maintenance, such that the system remained capabic of performing its intended function. Specifically, the Fort Calhoun Station's method for monitoring pipe wall thicknesses had used a predictive methodology to ensure that minimum wall thicknesses were not exceeded in the fourth stage extraction steam system. The Fort Calhoun Station improperly applied the methodology such that errors and omissions contributed substantially to erronevus predictions of wall thickness. Therefore, your staff's decision to monitor the system under paragraph (a)(2) of the rule was based on the improper implementation of the crosion/ corrosion program. As such, the Fort Calhoun Station did not demonstrate that the condition of these systems was being effectively controlled through the performance of appropriate preventive maintenance. As a result of the flaws in your erosion / corrosion program, the second downstream large radius piping sweep, in the fourth stage extraction steam system, ruptured on April 21,1997, which resulted in a plant transient. Also, the furthest downstream large radius piping sweep in the fourth stage extraction steam system line (S 32) was discovered to be below minimum wall thickness.

Based on the information developed during the inspection and the information that you provided during the conference, the NRC has determined that a violation of NRC requirements occurred. The violation is cited in the enclosed Notice of Violation (Notice)

and the circumstances surrounding it are described in detail in the subject inspection report. The violation involves a f ailure to comply with conditions of 10 CFR 50.65 in that, at the time the Fort Calhoun Station elected to monitor the condition of the nonsafety related steam extraction system under paragraph (a)(2) of the rule, it had not demonstrated that the condition of this system was being effectively controlled through the performance of appropriate preventive maintenance, such tt it the system remained capable of performing its intended function.

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Omaha Public Power District 3-The reactor safety consequences of the April 21 rupture of the extraction steam pipe were not significant. The plant was quickly shut down, plant operators appropriately responded to the event, no safety-related systems were challenged, arid no complications to the plant transient were caused by the rupture. This violation has been categorized in accordance with the " General Statement of Policy and Procedure for NRC Enforcement Actions" (Enforcement Policy), NUREG 1600 at Severity Level IV.

You are required to respond to this letter and should follow the instructions specified in the enclosed Notice when preparing your response. The NRC will use your response, in part, to determine whether further enforcement action is necessary to ensure compliance with regulatory requirements.

in accordance with 10 CFR 2.790 of the NRC's " Rules of Practice," a copy of this letter, its enclosure, ard your response will be placed in the NRC Public Document Room.

Sincerely,

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Ellis W. Merscpp'ff Regional Admidstrator Docket No. 50 285 License No. DPR 40 Enclosure: Notice of Violation cc (w/ encl):

James W. Tills, Manager Nuclear Licensing Omaha Public Power District Fort Calhoun Station FC-2 4 Adm.

P.O. Box 399 Hwy. 75 North of Fort Calhoun Fort Calhoun, Nebraska 68023-0399 James W. Chase, Manager Fort Calhoun Station P.O. Box 399 Fort Calhoun, Nebraska 68023

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Omaha Pubito Power District 4-Petry D. Robinson, Esq.

Winston & Strawn 1400 L. Street, N.W.

Washington, D.C. 20005 3502 Chairrnan Washington County Board of Supervisors Blair, tJebraska 68008 Cheryl Rogers, LLRW Program Manager Environmental Protection Section Nebraska Department of Health

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301 Centennial Mall, South P.O. Box 95007 Lincoln, Nebraska 08509 5007 l

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OEMAIL JDyer (JED2) .

EMerschoff (EWM) WBrown (WLB)

GSanborn (GFS) GMVasquez (GMV)

BHenderson (BWH) MHammond (MFH2)

CHackney (CAH) DKunihiro (DMK1) 4 AHowell (ATH) DChamberlain (DDC)

KPerkins (KEP) WJohnson' (WDJ)

JShackelford(JLS2) KBrockman (KEB)

PGwynn (TPG) WWalker (WCW)

RCorreia (RPC) DPowers (DAP)

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DOCUMENT NAME: G:\EA\ DRAFT \EA97280 DFT F, a.r'l To rece6ve copy or document, ind6cate in bou: "C" = Copy wMhout enclosures "E" * C wnh enclosures "N* a No copy ES SRA D:DRP NRR/ DRPH , D:DRSR MVasquez ' - JShackelf ord' - PGwynn' RCorreia'[f f AHowell P 08/ /97 08/ /97 08/ /97 08/.5/97 08/N/97 samma summasummmmmmmun mammammmmmmmmme summenummmmmmmuneammma JEDyer 3(jp EMerschoff 08/(/97 ' 08/ /97

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