ML19270G519

Final Deficiency Rept Re Pipe Stress Analysis Passing Through Main Steam Valve House.Manufacturer of Quench Spray Nozzle Pump Will Complete Work to New Specs & Return Pump to Svc Prior to Fuel Loading

ML19270G519
Person / Time
Site:	North Anna
Issue date:	06/06/1979
From:	Brown S VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
266B, NUDOCS 7906120178
Download: ML19270G519 (2)

Text

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a Vepco _ _. _ _... _ .._.. _ . _

June 6, 1979 Mr. James P. O'Reilly, Director Serial No. 2668 Office of Inspection & Enforcement PSELC/CES:mac: wang U. S. Nuclear Regulatory Conaission Regicn II Docket No. 50-339 101 Marietta Street, Soice E00 Atlanta, Georgia 30303

Dear tir. O'Reilly:

On Aprtl 11, 1973, NRC Region II was notified under the provisions of ICCFRSO.55(e) of a deficiency in tha pipe stress analysis for pipes passing througn the Unit 2 .4ain Steam Valve douse (HSVH). Tnts notification as followed by a 5-day report on April lo,1979 and by in interim report cated

' :1ay 10,1379.

Inese reports stated tnat it nao ceen determined tnat some Unit 2 pipe stress analyses for pipes passing through the MSVH used the seismic structural

.novements that had oeen determined fnr the Unit 1 MSVii. Due to the different founding conditions of tne two structures, the seismic structural responses of the Unit 2 MSVri are greater than those of the Unit 1 MSVH. A review of the pipe stress analyses aas been performed and has resulted in the identification of nineteen stress problems tnat required reanalysis.

Tite interia report indicated that Stone and Webster had completed the reanalyses of the stress problams using the appropriate MSVH seismic structural response. This necessitated the review of 283 pipe supports with 72 of the supports requiring modifications to accept the new loads within conservative design allowaoles or removal to reduce pipe stressas to within i

code allowables. This rework has now been completed.

l It was also stated in the interim report that the revised nczzle loads on the quench spray pumps had been submitted to the venoor, Ingersoll-Rand Co.,

for review and evaluation, but that the review had not Deen completed.

Verification has been received from Ingersoll-Rand Co. that the pump l design could withstand the new loads; however, Ingersoll-Rand Co. reconnends mocifications to the base attachment mechanism of the pumps for additional l

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conservatism. They nave concurred tnat tne added conservatism can be accomplished by replacement of the existing one inch diameter pump to bedplate 4 bolts ( ASTM A-307) with bolts of higher strength (ASTM A-325, or equ' valent).

The existing pump to bedplate bolts will be replaced with ASTM A-325 bolts torqued to tne vendor's specification. This work will De completed prior to fuel load.

0 2349 142 79061201'l?

Mr. James P. O'Retfly, Director 2 As the final system modifications outlined herein will result in a system capable of accomodating all the required loads, we anticipate no further correspondence on this subject. Therefore, this letter is considered to be a final report and completes all reporting requirements under provisions of 10CFR50.55(e) and/or 10CFR50.21.

eve!y. truly yours, Y I r

e

- Sad C. 3*o4n. Jr.

Senior Vice President - Power Station Engineering and Construction ec: "r. John G. Davis, Acting Ofrector Office of Inspection t. Enforcemant Harold R. Denton, Director Office of Nuclear Reactor Regulation 2349 143 R eiwn!@ g g Q

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