TXX-4844, Interim Deficiency Rept CP-86-36 Re S&W Pipe Support Reverification Program.Initially Reported on 860509.Addl Supports Will Be Added to Relieve Overstress Problem.Next Rept Will Be Submitted by 860813

Interim Deficiency Rept CP-86-36 Re S&W Pipe Support Reverification Program.Initially Reported on 860509.Addl Supports Will Be Added to Relieve Overstress Problem.Next Rept Will Be Submitted by 860813

ML20199C937
Person / Time
Site:	Comanche Peak
Issue date:	06/09/1986
From:	Counsil W, Keeley G TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	Johnson E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
CP-86-36, TXX-4844, NUDOCS 8606180406
Download: ML20199C937 (3)

Text

l Log # TXX-4844 File # 10110

, 903.9 TEXAS UTILITIES GENERATING COMPANY SKYWAY TOWER . 400 NORTH O1JVE STREET. L.B. 81. DALLAN. TEXAS 75301 June 9, 1986

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Mr. Eric H. Johnson, Director Division of Reactor Safety and Projects y)0g -

U. S. Nuclear Regulatory Commission g$l. .

611 Ryan Plaza Drive, Suite 1000 .e Arlington, TX 76012

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)

D0CKET NOS. 50-445 AND 50-446 PIPE SUPPORTS SDAR: CP-86-36 (INTERIM REPORT)

Dear Mr. Johnson:

On May 9,1986, we verbally notified your Mr. I. Barnes that the scope of plant modifications resulting from the project's pipe support reverification program could be considered potentially reportable under the provisions of 10CFR50.55(e). The engineering evaluation to date has identified one instance which is reportable under the provisions of 10CFR50.55(e). The evaluation of this issue is continuing and we anticipate submitting our next report by August 13, 1986.

Very truly yours, WECaud W. G. Co sil By: t/

G. S'. Khel Manager, Nu iconsing JCH/arh Attachment c - NRC Region IV (0 + 1 Copy)

Director, Inspection & Enforcement (15 copies)

U. S. Nuclear Regulatory Commission Washington, D.C. 20555

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A DIVis10N Of TEXAS UTIE2 TIES ELECittic COMPANY {

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ATTACHMENT PIPE SUPPORTS DESCRIPTION The issue involves the project's pipe support reverification program being conducted by Stone and Webster Engineering Corporation (SWEC). This program employs an expanded set of design and installation criteria for the evaluation of the structural adequacy of existing installations.

While the primary scope of SWEC's work is to provide technical verifications, modification of certain pipe supports will provide expedient acceptance for the expanded requirements. Initial results indicate support modifications are categorized as follows:

1. Prudent. Acceptance by physical modification versus analysis. Supports -

in this category may be technically acceptable; however, more time and expense would be involved than that required to physically modify the support and qualify the modification.

2. Recent NRC and Industry recommended practice. Modifications implemented to eliminate snubbers to enhance plant maintainability, reduce in-service inspection, and minimize worker exposure (operating plant conditions).

3. Adjustment. Minor modifications (such as re-torquing or shimming) implemented to meet.more rigorous installation criteria contained in the resolution of the ~ external- source technical issues.

4. Cumulative effects. Modifications that may be required due to the combined effect of multiple issues.

The scope of plant modifications resulting from this reverification program is of a magnitude such that it was considered potentially reportable under the provisions of 10CFR50.55(e).

The issue is applicable to Units 1 and 2 and involves all safety class piping systems.

The engineering evaluation to date has identified one instance which is reportable. On the seismic evaluation of stress problem 1-045T, for the chemical volume and control system (CVCS), the SWEC requalification has indicated an overstress condition. The cause for the condition was the use of inappropriate response spectra in the previous Gibbs and Hill piping analysis.

SUMMARY

OF' EVENTS Date NRC Notified as Potentially Reportable: May 9, 1986.

Date Determined Reportable: June 9, 1986.

SAFETY IMPLICATION The overstress condition in the CVCS, stress problem 1045T, were it to have remained uncorrected, could have adversely affected the safety of operation of the plant in the event of an earthquake.

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ATTACHMENT

• PIPE SUPPORTS continued CORRECTIVE ACTION Corrective action is to add sufficient additional supports to relieve the overstress problem. Appropriate spectra will continue to be used for all stress problems in the requalification program, as was being used when the condition was identified.

In addition to the above, the support modifications initiated to date, by category as. listed in the description section of this report, are as follows.

Unli Cateaory Number of Modifications I Prudent 992 Recent Industry Practice 177 Adjustment 0 Cumulative Effects 15 II Prudent 699 Recent Industry Practice 35 Adjustment 11 Cumulative Effe;ts 0 Subsequent status reports will continue to update the above list, and add additional support modifications which may be identified and initiated.

We anticipate submitting our next report no late than August 13, 1986, s

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