ML20058C342

Documents Completion of Evaluations Committed to Re IE Bulletin 79-14 Calculation Sample Program,Per

ML20058C342
Person / Time
Site:	Point Beach
Issue date:	09/05/1990
From:	Fay C WISCONSIN ELECTRIC POWER CO.
To:	Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
CON-NRC-90-91 IEB-79-14, VPNPD-90-395, NUDOCS 9011010174
Download: ML20058C342 (17)

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\\ Electnc PONER COMPANY 231 w Mchomt no Ion Mm masco wi 63201 914)221 2345 VPNPD-90-395 NRC-90-91 September 5, 1990 Mr. A. Bert Davis Regional Administrator, Region III U.S. NUCLEAR REGULATORY COMMISSION 799 Roosevelt Road Glen Ellyn, Illinois 60137 l

Gentlemen:

DOCKET 50-266 AND 50-301 IE BULLETIN 79-14 CALCULATION SAMPLE PROGRAM RESULTS EQINT BEACH NUCLEAR. UNITS 1 AND 2

Reference:

1) WE Letter VPNPD-89-429/NRC-89-096 to Mr. A. Bert Davis, dated 8/04/89.

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2) WE Letter VPNPD-90-239/NRC-90-050 to Mr. A. Bert Davis, dated 5/17/90.

i This letter documents the completion of the evaluations committed to be performed by Reference 1 regarding the IEB(79-1d program for the Point Beach Nuclear Plant.

The results of the~67aluations were summarized in Reference 2 and discussed in a meeting in' I

Region III offices on August 14, 1990.

This letter also provides our interpretation of these results and the r mosed program for further evaluations as discussed in the mee' A copy of the presentation at our meeting-is provided in A,_achment 1.

The tasks and evaluations which have been performed include the following:

1)

Sample 50 piping support calculations tx) determine the adequacy of the original.IEB 79-14 program support qualification methodologies and documentation.

This review was performed by an independent third party and

-the results were reported to the NRC in August 1989.

i 2)

Modify integral welded attachment (IWA) piping supports as identified in Reference 1.

The status of the modifications is the same as reported in. Reference 2.

l Those supports associated with the Unit i systems have been modified to meet Code compliance requirements and those supports associated with Unit 2 will.be modified during the upcoming refueling outage.

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Mr. A. Bert Davia 3eptember b, 1990 Page 2 3)

Review the remaining IWA ca:culetions' performed by Bechtel as-part of the orig nal'IEB 79-14 to determine impact on the acceptability 7f these supports.

The results of this review were.ieported-to the NRC-in Reference 2.

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_ Walkdown.and reconcile the fifteen piping system cal-l culations, as committed in Reference 1.

The results J

were summarized in Reference 2.and the individual reconciliations for those calculations that were not within the IEB 79-14 program tolerances are described in_.

5)

Develop criteria for justification for. continued operation.

These criteria were based on the Appendix F criteria set forth in the ASME B&PV Code Section III.

The criteria were submitted to.the NRC in August, 1989, and NRC concurrence was obtained in November, 1989.

o Additionally, as a result of earlier IWA evaluations, the-residual heat removal (RHR) systems outside containment fer both units-were i

line walkud and reevaluated using corrected input parameters.

i This work identified support load increases caused by'the use of i

the maximum normal operating temperature (340 F) versus the-j temperature assumed in the original 79-14 analysis (post LOCA tamperature of 210 F).

The seismic response also increased due to i

errors in assumptions regarding-the piping-insulation.

These load increases resulted in a total of.154' piping, support calculations and 44 supports requiring modification.<-The required modifica-j tions for Unit 1 have been implemented and those' required for. Unit 2 will be completed during the upcoming refueling outage.

l The stress calculation sampling programs, the IWA. evaluations and the piping support calculation: review evaluated 4270 feet of pipe and 462 supports and have provided a significant amount of data with which to draw conclusions regarding the.IEB 79-14 original program.

The calculation' review revealed weaknesses in documen-tation of acaumptions and standards._:The IWA review revealed methodologies that in some casesLwere non-conservative in the evaluation of local stresses on supports..The line walk samples.

revealed: discrepancies in some analyses when compared to the true as-built condition.

It has also been established as airesult of the sampling programs that the piping isometric:and support =

drawings require upgrading to be used as design documentation.

Despite these. errors and weaknesses in the original IEB 79-14 program, all piping and piping supports which were determined to be in excess of: code allowable stresses were within the operabil-ity criteria established for Point Beach Nuclear Plant.

Thus we believe there are no cperability concerns regarding safety related piping at Point Beach.

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Mr. A. bert Davis September 5, 1990 Page 3 1

-As discussed during the August 14 meeting, we propose to reevaluate the remaining portions of the original IEB 79-14 program in order to provide further assurance of no operability or.

safety concerns in safety related piping or support systems. The reevaluation will also provide documentation of Code compliance.

'n addition, we-believe this reevaluation will provide significant Lenefits in design basis documentation and possible plant-life extension activities.

This effort will include field walkdown of remaining safety related piping and supports,-reconciliation of-significant discrepancies, reanalysis as necessary, and upgrading of documentation for piping and piping supports.

We believe many of the errors and weaknesses in the origincl IEB l

79-14 program were-a result of the accelerated schedule imposed by the bulletin.

Thus, in view of the lack of operability concerns j

to date and the need to avoid similar errors in-the future, we i

propose to perform this work over a period of at least three years H

beginning in early 1991.

During the remainder of'1990, we expect to complete modifications and documentation of the reavaluations conducted to date.

We will provide periodic summaries of the status of this work and will notify you of any significant change j

in the schedule.

i Should you have questions regarding our evaluations to date or our proposed program for reevaluation, please contact us.

Very Truly Yours, s /

( b C. W. IFay Vice President Nuclear Power Copy to:

NRC Resident Inspector l

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ATTACHMENT:1 WISCONSIN ELECTRIC POWER COMPANY L

PRESENTATION MATERIALS lEB 79-14 MEETING AUGUST 141990 GLEN ELLYN, ILLINOIS

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i SAMPLING PROGRAMS

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4 FOR IEB 79 ~

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50 PIPING SUPPORT CALCS EVALUATED 15 PIPING SYSTEM CALCULATIONS RECONCILED 1

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TO CURRENT AS BUILT CONDITIONS 1'

ALL.PREVIOUSLY. CALCULATED IWA SUPPORTS RE-EVALUATED RHR OUTSIDE CONTAINMENT RE-ANALYZED.

IN DETAll~

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SAMPLING PROGRAM CONCLUSIONS

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i lEB 79-14

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• PIPING SUPPORT CALCS DO NOT MEET l

TODAY'S STANDARDS FOR DETAIL j

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• THE CONCLUSIONS MADE BY THESE SUPPORT CALCS ARE UNCHANGED l

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• THE PIPING ISOMETRIC DRAWINGS HAVE i

SUFFICIENT ERRORS TO: PRECLUDE THEIR USE AS DESIGN-DOCUMENTS:

• THE PIPING ANALYSES CONTAIN ERRORS j

• <NEW WALK DOWNSLREVEALED ERRORS IN j

l TRANSLATION FROM THE FIELD TO THE ANALYSISL l

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.i SAMPLING PROGRAM CONCLUSIONS

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i IEB 79-14

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• IWA PROBLEMS CAUSED BY MODIFICATIONS-PERFORMED FOR ORIGINAL 79-14 PROGRAM e-lWA PROBLEM RESOLVED;. ALL' MODIFIED IWA SUPPORTS EVALUATED AND REWORKED AS j

NECESSARY i

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IWA QUALIFICATION PROGRAM 1

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LINE mLK REANALYSIS

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SAMPLE QUANTITY 11i212 CALCS REQ'D L _) MODIFICATIONS REO'D i

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SUPPORT SAMPLING RESULTS l

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' QUANTITY l

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. TOTAL 15 CALC '

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'_ SAMPLE REANALYSIS j

i SAMPLE TYPE E SAMPLE QUANTITY iillill CALCS REQUIRED j

MODIFICATIONS REQ'D

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WISCONSIN ELECTRIC IEB 79-14

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RECONCILIATION PROGRAM

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• WISCONSIN ELECTRIC CONCERNS ARE RELATED TO CODE COMPLIANCE.

SYSTEM OPERABILITY HAS NOT BEEN lDENTIFIED AS A CONCERN.

• THE EXISTING AS BUILT DRAWINGS REQUIRE IMPROVEMENT TO BE USED AS DESIGN DOCUMENTS j

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. MANY PIPING AND SUPPORT CALCULATIONS DO NOT COMPLETELY DOCUMENT-ASSUMPTIONS OR JUDGEMENTS MADE, HOWEVER, SOUND TECHNICAL JUDGEMENTS OR STANDARDS' WERE EVIDENTLY USED i

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WISCONSIN ELECTRIC IEB 79 ~l:

RECONCILIATION PROGRAM

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• PERFORM PIPING LINE WALKS OF ALL REMAINING j

lEB 79-14 SCOPE PIPING

• RECONCILE-DISCREPANCIES IN PIPING AND SUPPORTS

• DEVELOP AS BUILT RECONCILIATION REPORTS FOR EACH STRESS CALCULATION

-Deviations within tolerances will be documented

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-Minor out of tolerance conditions-will be adjusted i-using hand cales and documented y

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-Major discrepancies will be reconciled using new stress analyses i

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t WISCONSIN ELECTRIC IEB 79-14

~j RECONCILIATION PROGRAM

• RECONCILIATION OF THE PIPING SUPPORTS INCLUDES; j

-New-calculations for supports where new loads 1

exceed previously qualified loads l

-New calculations for supports with as built configurations significantly d;7ferent than l

those qualified t

-Use of appropriate qualification techniques to j

account for IWA stresses-

-Supports without phyisical changes or increased loads will be considered acceptable based on the results of the 50 calculation sample 4

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l WISCONSIN ELECTRIC lEB 79-14

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RECONCILIATION-PROGRAM 1

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lSOMETRIC DRAWINGS ARE TO BE UPDATED AND j

MAINTAINED TO CURRENT AS BUILT CONDITIONS PIPING SUPPORT-DRAWINGS ARE TO BE UPDATED AND MAINTAINED TO CURRENT AS BUILT CONDITIONS i

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WISCONSIN ELECTRIC IEB 79-14 RECONCILIATION PROGRAM 4

• REASONABLE SCHEDULE REQUIRED TO AVOID ERRORS RESULTING FROM " CRASH" PROGRAM ENSURE ADEQUATE EFFORT FOR DESIGN BASIS i

DEVELOPMENT i

• NO OPERABILITY PROBLEMS FOUND AFTER SAMPLING APPROXIMATELY 15% OF THE ORIGINAL. PROGRAM i

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WISCONSIN ELECTRIC lEB 79-14

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i RECONCILIATION PROGRAM REMAINDER OF 1990

-Establish scope and priorities

-Evaluate contractors

-Complete installation and' documentation of j

earlier sampling program support modifications BEGIN RECONCILIATION PROGRAM JANUARY 1991

-Expect 31 year ' minimum duration 1

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--Periodic progress presentations to Region lli 4

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ATTACHMENT.

WISCONSIN ELECTRIC POWER-COMPANY-i i

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IEB 79-14 SAMPLE : PROGRAM l

RECONCILIATIONS L

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j As committed in reference 1 of this letter a sampling of the IEB 79-14 piping stress calculations was made to determine the adequacy of the original IEB 79-14 program. Line walks associated with 15 calculations were conducted by Bechtel and Wisconsin Electric personnel. Included was 2340 feet of pipe and 225 piping supports.

Four of the 15 calculations required reanalysis as described below:

1.

Service Water (Calculation 7-20)

Errors in the seismic boundary determination at the time of the original 79-14 program led to an underestimation of the piping support loads at three supports.

Three supports required minor upgrades although operability was not compromised.

The upgrades have been performed and the system now meets code requirements.

2.

Condensate Storace Tank Pioina (Calculation 2-9)

Deviations between the actual as-built and the design drawings in the non-seismic portion of the piping system warranted a reanalysis of the piping to determine the impact in the seismic portion of the system.

Further investigation of the supports in the non-seismic region identified installation weaknesses and other support problems that required correction.

The system was determined to be operable and the required support repairs have been completed.

The system now meets code requirements.

3.

Unit 2 Containment Sorav (Calculation 15-14)

This portion of the system was not specifically analyzed during the original 79-14 program. This system was considered identical i

to a redundant portion of the system which had been analyzed.

The 1989 line walk indicated that they were not identical and that a computer reanalysis was required.

The reanalysis met code requirements, however, an anchor associated with=this line (and four other lines) requires rebuilding to meet code requirements.

This modification will be completed during the Unit 2 refueling outage this fall.

4.

Unit 2 Safety Iniection (Calculation 15-16)

The field walk down did not identify deviations significant enough to warrant re-analysis.

Errors in accounting for loads on two gang supports led to increased loads on these supports.

The increased loads on one support exceeded the Code limits although operability limits using N-411 damping analysis were met. A redesign for this support is in process and the modified support will be installed during the Unit 7 refueling outage, this fall.

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