ML19256G059

LERs 79-033/01T-0 & 79-034/01T-0:on 791205,during Seismic Analysis Required by IE Bulletin 79-14,pipe Supports in Five Sys Discovered to Have Potential Stress in Dbe.Caused by Design Deviation.Mod Supports

ML19256G059
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	12/19/1979
From:	Conway W VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19256G057	List: ML19256G056 ML19256G059
References
79-034-01T-0, 79-34-1T, LER-79-033-01T, LER-79-33-1T, NUDOCS 7912270338
Download: ML19256G059 (2)

Text

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LICENSEE EVENT REPORT LER 79-33/1T and 79-34/1T CONTROL BLOCK: l 1

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(PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 7 o i 8 3 VITlV YlSl1l@l0 LICENSEE CODE 14 15 0 -l0 0 0 0 LICENSE NVM8ER 0 -

0 0 @l4 1l1l1 25 26 LICENSE TYPE J0 1 @l l 57 C AT 58 CON'T 0 1 "$RC c l L @l 0l 5 l 0 l 0 l 0 j 2 l 7 l 1 @l 1 l 2 l 0 l 5 l 7 l 9 74l@l 1 l 2REPORT 75 l 1 l DATE 9 l 7 l 990l@

3 60 61 COCKET NLM8ER 68 69 EVENT DATE EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h l

o  ? l o a See attached sheet i o 4 l c 5 l I

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SO 7 8 3 SYSTEM CAvSE CAUSE COYP. VAI.V E COCE CODE SUSCODE COMPONENT CCDE SU8COCE SUSCODE O 9 l Xl d@ l Bl@ l A l@ lS lU lP l0 [R lT l@ l X @

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7 8 9 11 12 SECUENTI AL CCCURRENCE REPORT REVISION

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CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h 1 0 l l I

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$ AT  % POWER CTHER STATUS SCO RY OiSCOVERY OESCR:PTION 1 6 d @ l0 9l6l@l NA l l C lhl Investigation relating to NRC Bul. 79-14 l A CTIVITY C0 TENT RELEASED CF RELE ASE AMOUNT OF ACTIVITV LOCATION OF RELEASE 7

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1. ERSCNNEL EXPOSURES NUMBER TYPE OESCRiPTICN 1 7 l Ol 0l Olh Z lhl NA l

• ERSCNNE L INJLRiES NUveER CESCR:PTicNh 1

1 a 8 9 0l 0 0lhl 11 12 NA l 80 LOSS OF OCR DAMAGE TO FACIL!TV Q j f QjQ TvoE E SC Rip TIC N v [Q UlJ 7

1 9 3 9 l2lh 19 NA 80 rSSUE DESCPIPTION 7g }Q3 h o r

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NAME OF DAEPARER 4. F. Conway PHONE: S02-237-77Il S,

VTVYS1 050-0271 LER 79-33/lT LER 79-34/1T EVENT DESCRIPTION AND PROBABLE CONSE ,c ..

This Reportable Occurrence updates .ae events pr1viously reported in R0s 79-33/IP and 79-34/lP. During the seismic analyses to determine the adequacy of all Seismic Class I pip .' , as required by an NRC letter from Mr. Boyce H. Grier to M . -N n H. Groce dated October 24, 1979, and NRC Bulletin 79-14, ..s discovered that pipe supports in portions of five systems had tne potential to exceed the code allowable stress in the event of a design basis earthquake. Plant operation was continued for seven days while the supports were rede-signed and modified as allowed by the above referenced NRC letter. Based on the above and the lack of any design basis earthquake, there were no consequences to the health and ife!" af the public due to this event.

The applicable supports are listed be'.ow. There have been no other sup-ports reported to the Commission as subject to Code overstress.

Previously Reported System Deff.iency Under LER#

CS Part 2 Dead load supports C5-HD553 and CS-HD85D were 79-33/1P modified to provide tverticalload capability.

SW Part 10 Dead load supports RSW-H231, RSW-HD141C, and 79-33/IP RSW-HD231B were modified to provide i vertical and load capability. 79-34/IP AC Part 1 A new support (ASCP-HD-22B) with vertical and 79-33/IP lateral load capability was added in torus area below the floor penetration at El. 252' .

Dead load supports RHR-HD205A and RER-H119 were modified to provide i vertical load capa-bility.

SW Part 6 Supports RSW-HD254, RSW-HD39, and RSW-HD177B 79-33/lP were modified to provide i vertical load capa-bility.

RHR Partll Dead load support RHR-HD200C was modified to 79-34/lF provide i vettical load capability. A new sup-port (RER-HD-187C) was added to provide +

vertical load capability adjacent to support RHR-HD156B. The baseplate for support RHR-HD200E was stif fened.

CAUSE DESCRIPTION AND CORRECTIVE ACTIONS The cause of this event was due to deviations from the piping design iso-metrics. All required redesigns and support modifications were performed within seven days of the disovery of the occurrence. This reportable occurrence includes all support deficiencies discovered in the seismic analyses required by NRC Bulletin 79-14.

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