ML19210C691

LER 79-047/03L-0:on 791010,prestressed Concrete Realtor Vessel Cooling Water Sys Determined Impaired.Caused by Insufficient Hangar Base Plate & Bolts Out of Concrete.Base Redesigned & Modified to Provide Adequate Strength

ML19210C691
Person / Time
Site:	Fort Saint Vrain
Issue date:	11/09/1979
From:	Gahm J PUBLIC SERVICE CO. OF COLORADO
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19210C688	List: ML19210C687 ML19210C691
References
LER-79-047-03L, LER-79-47-3L, NUDOCS 7911190434
Download: ML19210C691 (3)

Text

NRC PORM 366 U. S. NUCLEAR REGULATORY COMMISSION mm

. 1.lCENSEE EVENT REPORT CONTROL BLOCK: l 1

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6 (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATIONI 0 1 8 9 Cl0 FlSlVl1l@160 l0 -l0l0l0l0l0 - l 0 l 0 l@26 14 uCENSE NuMSER 26 4 1 1 l 2 l 0 l@l67 CAT LICENSE TYPE J3 l

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7 8 5 uRCE dl 60 0l5l0l0 61 l 0 l 2 l 6 l 7 68hl 169 ln l1 DOCKET NUMBER ln l 7 I 9 l@l 1 11 EVENT DATE 74 75 0l DATE REPORT 91 7l 980 @

EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h O 2 lOn October 10.1979. at 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br /> the c res tressed concrete resitor vessel cooline l O 3 I water system was determined to be impaired due to an impaired hanger.11A-H-46890.

O 4 1 This is a degraded mode of Fort St. Vrain Technical Specification LCO 4.3.10 and is l O s l reportable per Fort St. Vrain Technical Specification AC 7.5.2(b)2. There was no l O s ] affect on public health and safety. l 0 7 1 l O 8 l l

E CO E SU C E COMPONENT CODE St. SCOdE SU E TF1T1 7 8 I c l a l@ L.s_l@ l A lh lS lU lP l0 lR lT @ Wh W@

9 10 11 12 13 18 19 20 SEQUENTIAL OCCURRENCE REPORT REVISION

, LE R /RO EVENT YEAR R EPORT NO. CODE TYPE N O.

@ RE g 7 19 l l-l 0l 4l 7l l/l l 013 l lLl l-l l 0l 21 22 23 24 26 27 28 29 30 31 32 TKN AC O O P NT ME HOURS S8 i POR 8. SU L MANUP C RER l33r l@l34z l@ l35z l@ Lz_J@ l 01 0 01 0l Ly.j@ N l@ LA_l@ lE l0 6 15 l@

36 31 40 41 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h i O lThe hancer. 11A-H-46890. base plate was insuf ficient and the anchor bolts had oulled g Iout of the concrete. The hanger was inadequate and the base was redesigned and I y w l modified to provide adequate strength. No further corrective action _is antipated or i 1 3 req uired. l U_,j,,4.j l l 7 8 9 80 STA  % POWER OTHER STATUS DIS O RY DISCOVERY CSSCRIPTION i s [E,J@ l0 l 3 l6 l@l N/A l lC l@l Engineering Analysis of Hangers l A TlVITY CO TENT RELEASED OP RELEASE AMOUNT OP ACTIVITY LOCATION OP RELEASE 1 6 [.Z,,j @ @lN/A l N/A PERSONNEt ExPOSOES NUM8ER i 7 l 0 l 0 l 0 lhlZlTYPEN/A

@l DESCRIPTION l PERSONN E L INJURIES NUM8ER DESCRIPTION 7

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NAME OF PREPARER _ __

J.W. Gahm PHONE: (303) 785-225'l E,

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REPORT DATE: November 9. 1979 REPORTALLE OCCURRENCE 79-47 ISSUE O OCCURRENCE DATE: October 10, 1979 Page 1 of 2 FORT ST. VRAIN NUCLEAR GENERATLNG STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 191/2 PLATIEVILLE, COLORADO 80651 REPORT NO. 50-267/79-47/03-L-0 Final IDENTIFICATION OF OCCURRENCE:

At 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br /> October 10, 1979, the PCRV cooling water system was determined to be impaired due to an impaired hanger,11A-H-46890. This is a degradec' mode per Fort St. Vrain Technical Specification LCO 4.3.10 and is reportabAe per Fort St. Vrain Technical Specification AC 7.5.2(b)2.

EVENT DESCRIPTION:

On October 10, 1979, with the plant operating at 36% thermal power and 140 W electrical power, a hanger,11A-H-46890, was determined to be impaired and also caused System 46 to be considered impaired.

This put the plant in a degraded mode of Fort S t. Vrain Technical Specification LCO 4.3.10 which allows 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of continued operation while the hanger is being repaired. The necessary work was done and the hanger returned to service October 12,1979, at 1645 hours0.019 days <br />0.457 hours <br />0.00272 weeks <br />6.259225e-4 months <br /> within the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> limit.

CAUSE DESCRIPTION:

The hanger base plate was inadequate and the anchor bolts had pulled out of the concrete.

CORRECTIVE ACTION:

The base plate was redesigned and the hanger modified accordingly. There was no affect on public health or safety and no further corrective action is anti-cipated or required.

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REPORTABLE OCCURRENCE 79-47 ISSUE O Page 2 of 2 Prepared by: [ p Asa B. Reed Technical Services Technician Reviewed by:

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. W.'Cahm Technical Services Supervisor Reviewed by:

Frank M. Mathie Operations Manager Approved by: N h b.

Don Warembourg N '

Manager, Nuclear Production 1353 054