ML20023D902

LER 83-017/01T-0:on 830512,insp Performed Per IE Bulletin 83-03 Identified Six of Eight Check Valves Frozen in mid- Position.Caused by Corrosion & Rusting Valve Internal Parts. Valves Cleaned & Internal Components Replaced

ML20023D902
Person / Time
Site:	Fort Saint Vrain
Issue date:	05/26/1983
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
IEB-83-03, IEB-83-3, LER-83-017-01T, LER-83-17-1T, P-83190, NUDOCS 8306060134
Download: ML20023D902 (7)

Text

. NRC FORM 36G U. S. RUil LEAR REGULATORY COMMISSION (7 71) . o

- LICENSEE EVENT REPORT CONT Rol 8 LOCK: l l l l l l l (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 1 6 lo lil8 l9t l 0LICENSEE F

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7 8 60 61 DOCK ET NUVBER 68 69 EVENT oATE EVENT DESCRIPTION AND PROBABLE CONSEQUENCES O'o l o l 2 l 01 n May 12 and May 16, 1983, an inspection was performed to verify the operability and l

,,,3, , reliability of the check valves associated with the raw cooling water supply lines to ;

,, ,,, ; emergency diesel generator sets l A and 18. The inspection, performed pursuant to the l

,, ,3 y ,fluclear Regulatory Commission IE Bulletin fio. 83-03, identified that six of eignt of  ;

l0 l6 l l the check valves were frozen in mid-position. The results of the insoection are  ;

o ,  ; reportable per Fort St. Vrain Technical Specification AC 1.5.2(a)9. fio affect on g public health or safety. fio accompanying occurrence. fio similar reports.  ;

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42 l43NI@ l44wI 013101@ 47 CAUSE DESCRIPiloN AND CORRECTIVE ACTloNS i o lThe apparent cause is attributed to' corrosion and rusting of the check valve internal l 3 , l parts. lhe check valves were disassembled and cleaned, internal components were re- l

, , ;placed, and disc seats were lapped, as required. the valves will be routinely inspec-l

,,g3, l ted as part of an annual preventive maintenance prooram. No further corrective action l

, , ,is anticipated or required.  ;

7 8 9 80 ST S  % POWER OTHER ST A TUS CISCOV RY DISCOVERV DESCRtPTION 37 i s [Gj @ l0 l Ul 0l @ l ft/A l [Dj@l Inspection Pursuant to IE Bulretin No. l ACTIVI T Y CO TENT RELE ASED OF RELE ASE AVOUNT CF ACTIVITY LOCATION OF RELE ASE 7

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FACS I!!ILE May 12,1983 MR. JOHN T. COLLINS, REGIONAL AD:iINISTRATOR REGION IV NUCLEAR REGULATORY COMMISSION 611 RYAN PLAZA DRIVE SUITE 1000 ARLINGTON, TX 76011 i

i ON TilURSDAY, MAY 12,1983, AT 0900 IIOURS, WHILE Tile PLANT UAS SHUT DOUN AND AN INSPECTION OF RAW WATER CIDiCK VALVES SUPPLYING COOLING WATER TO THE j EMERGENCY DIESEL GENERATOR SETS (PURSUANT TO I & E BULLETIN 83-03) WAS IN PROGRESS, IT WAS DETER! FINED THAT FOUR OF FOUR CllECK VALVES ASSOCIATED WITH Tile 1B DIESEL GENERATOR SET WERE FROZEN IN THE MID-POSITIO:I APPARENTLY DUE l

i TO CORROSION. CORRECTIVE ACTION IS IN PROGRESS . IT IS ASSUMED THAT SIMILAR CONDITIONS EXIST CONCERNING THE FOUR Cl!ECK VALVES ASSOCIATED WITil TIIE 1A DIESEL GENERATOR SST. ALL VALVES WILL BE INSPECTED / REPAIRED PRIOR TO REACTOR OPERATION AT POUER. A DETAILED REPORT WILL FOLLOW.

Ti(IS EVENT IS REPORTABLE PER FORT ST. VRAIN TECliNICAL SPECIFICATION AC 7.3.2(A)9 AS REPORTABLE OCCURRENCE NO. 50-26 7/ 83-017/01-T-0.

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, PLEASE CONFIRM RECEIPT OF THIS TRANSMITTAL BY CALL BACK TO FRANK NOVACl!EK AT (303) 785-2224, EXTENSION 270.

l FRANK NOVACilEK PUBLIC SERVICE COMPANY OF COLORADO i FORT ST. VRAIN NUCLEAR GENERATING STATION l 16805 UELD COUNTY ROAD 19 1/2 PLATTEVILLE, COLORADO 80651 1

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REPORT DATE: May 26, 1983 REPORTABLE OCCURRENCE 83-017 ISSUE O OCCURRENCE DATE: May 12, 1983 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 19 1/2 PLATTEVILLE, COLORADO 80651-9298 REPORT NO. 50-267/83-017/01-T-0 Final IDENTIFICATION OF OCCURRENCE:

On May 12, 1983, and May 16, 1983, an inspection to verify the operability and reliability of the check valves in the raw cooling water supply lines to emergency diesel generator set IB (K-9202) and emergency diesel generator set 1A (K-9201) was performed. The inspection, performed pursuant to the Nuclear Regulatory Commission I & E Bulletin No. 83-03, identified that six of eight check valves were frozen in mid position. This event is reportable per Fort St.

Vrain Technical Specification AC 7.5.2(a)9.

CONDITIONS PRIOR TO OCCURRENCE:

Cold shutdown i

DESCRIPTION OF l OCCURRENCE:

On May 12, 1983, with the reactor in a shutdown condition, an inspection of the check valves in the raw cooling water supply lines to the emergency diesel generator set IB (K-9202) identified that four of four discs in the cooling water check valves were " frozen" in the mid position, apparently due to internal rust and corrosion.

L-Operability of the emergency diesel generator set 1A was verified prior to removal from service of the IB emergency diesel generator set for the required inspection.

On May 16, 1983, with the reactor in a shutdown condition, an inspection of the check valves in the raw cooling water supply lines to the emergency diesel generator set IA (K-9201) identified that two of four discs in the cooling water check valves were " frozen" in a partially open position, apparently due to internal rust anc corrosion. The swing check discs in the remaining two valves had I free movement on the hanger pin.

Operability of the emergency diesel generator set 1B was verified prior to removal from service of the 1A emergency diesel generator set for the required inspection,

REPORTABLE OCCURRENCE 83-017 ISSUE 0 4 Page 2 of 4 APPARENT CAUSE OF OCCURRENCE:

Unusual service conditions, including environment.

The apparent cause is attributed to a combination of corrosive wear and a buildup of rust in the check valve internal parts. There was no evidence of separation between the valve disc and the hinge arm in the eight check valves inspected.

The table below identifies applicable information from the NPRD-2 report of engineering data on the valves inspected.

VALVE D/G SET NUMBER CONDITION AS FOUND NPRO-2 ENGINEERING DATA IB V-42813 Frozen Mid-Position Walworth, one way flow check, cast iron fabricated, 4.0 inch, Model No. 63221.

1B V-42814 Frozen Mid-Position Walworth, one way flow check, cast iron fabricated, 4.0 inch, Model No. 63221.

1B V-45811 Frozen Mid-Position Walworth, one way flow check, cast iron, cast, 3.0 inch, Model No. C322.

I 18 V-45812 Frozen M d-Position Walworth, one way flow check, cast iron, cast, 3.0 inch, Model No. C322.

lA V-42815 Frozen 3/4" Off Walworth, one way flow check,

! Seat cast iron fabricated, 4.0 inch, Model No. 63221.

1A V-42816 Free Disk Movement Walworth, one way flow check, cast iron fabricated, 4.0 inch, Model No. 63221.

lA V-45814 Frozen 1/4" Off Walworth, one way flow check, Seat cast iron, cast, 3.0 inch, Model No. C322.

lA V-45313 Free Disk Movement Walworth, one way flow check, cast iron, cast, 3.0 inch, Model No. C322.

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REPORTABLE OCCURRENCE 83-017 ISSUE O Page 3 of 4 ANALYSIS OF OCCURRENCE:

An accumulation of rust and corrosion around the hanger and hanger pin inhibited free movement of the hanger and disc assembly in the check valves found defective during the inspection of 1A and IB emergency diesel generator sets.

CORRECTIVE ACTION:

All eight check valves on the raw cooling water supply to both diesel generator sets were disassembled, and the rust and corrosion were l removed from the valve internals. The disc seats were lapped as l required. Repair parts were installed where necessary. All repairs were completed while the reactor was in a shutdown condition.

In compliance with the Nuclear Regclatory Commission I & E Bulletin No. 83-03, an inspection of the raw water supply check valves associated with the emergency diesel generator heat exchangers is being incorporated into an annual preventive maintenance program.

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l' REPORTABLE OCCURRENCE 83-017 ISSUE 0 Page 4 of 4 Prepared By: ed Robert A. Dicksrson

~d Senior Technical Services Technician 1

Reviewed By: h- _X L.d _

TraTkTJTjlovach'ek '

Technical Services Engineering Supervisor Reviewed By: U,I f

'L. M. McBride L(

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Station Manager .

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l Approved By: /M2? /ds_ f,k )

Don Warembourg l Manager, Nuclear Production l

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c' Public service company ce Oranzeds 16805 Road 19 1/2, Platteville, Colorado 80651-9298 g

May 26, 1983 }Jh$ hkb y

Fort St. Vrain i t a, Unit No. 1 \ D li P-83190 A_

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Mr. John T. Collins, Regional Administrator Region IV Nuclear Regulatory Commission 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76011

Reference:

Facility Operating License No. DPR-34 Docket No. 50-267

Dear Mr. Collins:

Enclosed please find a copy of Reportable Occurrence Report No. 50-267/83-017, Final, submitted per the requirements of Technical Specification AC 7.5.2(a)9.

Also, please find enclosed one copy of the Licensee Event Report for Reportable Occurrence Report No. 50-267/83-017.

I Very truly yours, l

QM .

Don Warembourg Manager, Nuclear Production DW/cls Enclosure cc: Director, MIPC Q

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