ML20024A852

Updated LER 80-041/03X-2:on 800724,one of 12 Helium Circulator Seal Malfunction Pressure Differential Switches Discovered W/Trip Point Outside Tech Spec Limits.Caused by Dirt Accumulation in Electrical switches.W/830622 Ltr

ML20024A852
Person / Time
Site:	Fort Saint Vrain
Issue date:	06/22/1983
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
LER-80-041-03X, LER-80-41-3X, P-83219, NUDOCS 8307010041
Download: ML20024A852 (8)

Text

Nac Foa* U. S. NUCt EA7 CE2ULATOF.Y COMMISslON

, ,, r UCENSEE EVENT REPORT l

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(PLEASE PRINT OR TYPE ALL REQUIRED INFORMATIONI lo lil8I 9C l 0LICENSEE l F l CODE S l V I 1 l@l 14 lb 0 l0 l- 10 l0101010 l- 101025 l@l4 llLICENSE LICENSE NUMBER 2tp 11 1210 l TYPE JOl@l$7 C A T bd l@

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10111 sj',"c, I L lgl 0 l 5 l 0 l 0 l 0 l 2 l 617 l@l69 01712 l 4 l 8 l 0 74l@l0 l bREPORT EVENT DATE 7S l 2 l DATE 2 l u 1380l@ I 7 8 60 61 DOCK ET NUMBER 68 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h i o 12 i [ During July testing, one of the twelve helium circulator seal malfunction pressure l g , differential switch units was discovered to have a trip point outside the limits of l

, , ,LCO 4.4.1, Table 4.4-3. During August's testing, four of the twelve switch units l g [ere found to trip outside these limits. These are reportable per Fort St. Vrain l

,, ,, , , Technical Speci fications AC 7.5.2(b)1 and AC 7.5.2(b)2. Ito affect on public health ori

, , , , , , s a fe ty . Redundant system available and operable. Similar mports are R0's 77-47, l 78-27, 79-32, 79-56, 80-07, 80-16, 80-20, 80-26, and 80-34.  ;

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41 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h g 3,o i lITT Barton liodel 2C9 pressure differential switches failed to actuate at trip point l g i ue dto dirt accumulation in electrical switches. The ITT Barton pressure differential i

, , , indicating switches were replaced with ITT Barton Model 762 pressure transmitters and i g ; bistable trip modules (Model PT-3D, manufactumd by General Atomic Comoany) via Chance l g ,flotice 1110. flo further corrective action is anticipated or required. i s P

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NAME OF PREPARER ^' 3 PHONE: (303) 785-2224 2 o

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public Servlee Company *2 OcBondo Y ,

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16805 Road 19 1/2. Platteville, Colorado 80651-9298 g 60' }

June 22, 1983

Fort St. Vrain Unit No. 1 l P-83219

• R@R MRw Mr. John T. Collins, Regional Administrator Region IV Nuclear Regulatory Commission J#l271983

. 611 Ryan Plaza Drive ~ ,j Suite 1000 '

Arlington, Texas 76011 _ _ _

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

Dear Mr. Collins:

i j Enclosed please find a copy of Reportable Occurrence Report i No. 50-267/80-41, Revised Final, submitted per the requirements of Technical Specification AC 7.5.2(b)1 and AC 7.5.2(b)2.

Also, please find enclosed one copy of the Licensee Event Report for Reportable Occurrence Report No. 50-267/80-41.

Very truly yours, WW f Don Warembourg V Manager, Nuclear Production DW/cis Enclosure cc: Director, MIPC b

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W Number of Cel les De pa r tme n t o f E ne r gy - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1 (P Letter)

San Francisco Operations Office ATTN California Patent Group 1333 Broadway Oakland, California 94612 Dep a r tme n t o f E ne r gy - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1 (P Letter)

Mr. Glen A. Newby, Chief HTR Branch Division of Nuclear Power Development Mail Station 8-107 Washington, D.C. 20545 De pa r t men t o f Ene rgy - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1 (P Letter)

Project Manager AIT:4 Dr. Seighley P. O. Box 81608 San Diego, CA 92138 ifr. John T. Collins, Regional Administrator ------------------- Original of P Letter) nagion IV Nuclear Regulacory Constission eli Ryan Plaza Drive Suite 1000 Arlington, Texas 76011 Mr. Philip C. Wagner, Project Manager ---------------------- 1 (P Letter)

Region IV Nuclear Regulatory Conseission 611 Ryan Plaza Drive Suite 1000 <

Arlington, Texas 76011 f

D i re c t o r - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1 (P Letter)

Office of Management Information and Program Control Nucletr Regulatory Commission

'44shington, D.C. 20555 INP0 Records Center - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1 (P Letter)

Suite 1500 1100 Circle 75 Parkway Atlanta, Georgia 30339

fr. Pdke Dolphin. FSV. CA Technologies. Inc. Site Representative - - - - - - - - - 1 (P Letter)

Ceneral Atomic Technologies Inc.

16864 Wald County Road 191/2 e Platteville, Colorado 80651 f

NRC Resident Site Inspector --------------------------- 1 (P Letter)

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REPORT DATE: June 22, 1983 REPORTABLE OCCURRENCE 80-41 ISSUE 2 OCCURRENCE DATE: July 24, 1980 Page 1 of 5 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 19 1/2 PLATTEVILLE, COLORADO 80651-9298 l REPORT NO. 50-267/80-41/03-X-2 l Revised Final IDENTIFICATION OF OCCURRENCE:

During the July performance of the monthly check of the helium circulator seal malfunction pressure differential switches, it was discovered that one of twelve switch units tripped outside the limits specified in LCO 4.4.1, Table 4.4-3.

During the August performance of the monthly check of the helium circulator seal malfunction pressure differential switches, it was discovered that four of the twelve switch units tripped outside the limits specified in LCO 4.4.1, Table 4.4-3.

This is reportable per Fort St. -Vrain Technical Specifications AC 7.5.2(b)1 and Ac 7.5.2(b)2.

EVENT DESCRIPTION:

During normal plant operation, instrument personnel performed the circulator seal malfunction (buffer-mid-buffer) switch operability check. The switches are normally calibrated on an annual basis; however, due to the problems cited in the previous reports as listed on the LER, a check of buffer-mid-buffer trip settings on a monthly

- basis was undertaken as an interim measure to test operability.

There are twelve buffer-mid-buffer switch units, three per circulator. Each switch unit contains two electrical switches. The range of the sensing element is from (-) 100 inches of water to zero to (+) 100 inches of water. One of the electrical switches in each unit must operate at greater than or equal to (-) 10 inches water (negative buffer-mid-buffer), and the other electrical 'swi tch must operate at less than or equal to (+) 80 inches water (positive buffer-mid-buffer) per Table 4.4-3.

The trip settings for the twelve switch units are listed in Table 1 for July and in Table 2 for August.

The switch settings which were found to be less conservative than those established by the Technical Specification did not prevent the fulfillment of the functional requirements of the system.

REPORTABLE OCCURRENCE 80-41 ISSUE 2 l

Page 2 of 5 CAUSE DESCRIPTION:

Dirt buildup and accumulation in the electrical switches prevented them from making proper contact.

CORRECTIVE ACTION:

The trip settings of the electrical switches were re-adjusted to the proper trip points.

Due to the continuing problems being experienced with the electrical switches, the interim check of the trip settings was conducted on a monthly basis.

The problem was investigated, and the process activated pressure differential switches were replaced with pressure differential transmitters and solid state dual bistable trip modules. The new units eliminate the use of electrical contacts and, therefore, reduce the probability of fouling by dirt and/or corrosion from the working

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environment. This modification was performed via Public Service Company Change Notice 1110.

No further corrective actions are anticipated or required.

o y s v-r w ' y - +

m REPORTABLE OCCURRENCE 80-41 ISSUE 2 Page 3 of 5 TABLE 1 I I I l As Found Inches H2 O I As Left Inches H2_0 l l Increasing l Decreasing l Increasing l Decreasing l l Trip Point l Trio Point l Trip PointlTrip Point l l l l l l l 1 l1A Circulator lPDIS-211491 +76 l -8 l +76 l -8 l l l l l l 1 l l lPDIS-211511 +78 l -8 i +78 1 -8 l l l 1 1 I I I l IPDIS-211531 +75 l -5 1 +75 l -5 l 1 1 I I I I I l1B CirculatorlPDIS-211551 +77 l -6 +73 l -6 l l l l l l l l lPDIS-211571 +73 l -30 @ l +72 1 -5 l l l 1 1 I I I l lPDIS-211591 +72 l -8 l +77 l -8 l 1 1 I I I I l l1C Circulator lPDIS-21150l +75 l -5 l +75 -5 l l l l l l l l lPDIS-211521 +75 l -7 l +75 1 -7 l l l l l l l l l IPDIS-211541 +75 l -3 l +75 l -3 l l 1 1 I I I I l1D Circulator lPDIS-211561 +73 l -7 I +73 1 -7 l l l l 1 1 I I l lPDIS-211581 +74 l -6 l +74 l -6 l l l l l l l l l lPDIS-211601 +75 1 -8 l +75 1 -8 l

@ Denotes switch which was out of tolerance.

REPORTABLE OCCURRENCE 80-41 ISSUE 2 Page 4 of 5 TABLE 2 I I I l As Found Inches H2O I As Left Inches H 0_l l Increasing l Decreasing l Increasing l Decreasing l ITrip PointlTrip PointlTrip Point l Trip Point l 1 1 I l l l l l1A Circulator lPDIS-211491 +75 1 -5 l +75 I -5 l l l l l l l l l lPDIS-211511 +77 l -8 l +77 l -8 l l 1 1 I I I I l lPDIS-211531 +73 1 -17 O l +73 l -6 l 1 1 I I I i 1 11B Circulator lPDIS-211551 +82 @ l -6 l +78 l -6 l l l l l l l l l lPDIS-211571 +77 l -7 l +77 l -7 l l l l l l l 1 l lPDIS-211591 +77 1 -9 I +77 l -9 l l l l l l l l l1C Circulator lPDIS-211501 +78 l -4 1 +78 l -4 l l l l l l 1 l l lPDIS-211521 +77 l -9 I +77 l -9 l l 1 1 I I I I l lPDIS-211541 +77 l -8 I +77 l -8 l l 1 I I I i l1D Circulator lPDIS-211561 +73 l -50 @ Il +73 1 -5 l l 1 1 -

1 I l l l lPDIS-21158! +75 1 -7 l +75 l -7 l l l l 1 l l l lPDIS-21160l +75 l -47 @ ll +75 l -9 l

' @ Denotes switches which were out of tolerance.

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REPORTABLE OCCURRENCE 80-41 ISSUE 2 Page 5 of 5

.D Prepared By: MW 2 u w- -

Robert A. Dickerson Senior Technical Services Technician b

Reviewed By:

Frank'XNovachek Technical Services Engineering Supervisor Reviewed By: l,#fkt CEv3 /[ /(gy/

L. M. McBride 'g Station Manager Approved By: b h4M.

Don Warembourg /

Manager, Nuclear Prodbetion o

_ . _ . . . .-