05000267/LER-1981-024, Forwards LER 81-024/03L-0.Detailed Event Analysis Encl

Forwards LER 81-024/03L-0.Detailed Event Analysis Encl

ML19352B161
Person / Time
Site:	Fort Saint Vrain
Issue date:	04/16/1981
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19352B162	List: 05000267/LER-1981-024, Forwards LER 81-024/03L-0.Detailed Event Analysis Encl
References
P-81125, NUDOCS 8106030245
Download: ML19352B161 (6)

LER-1981-024, Forwards LER 81-024/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2671981024R00 - NRC Website

text

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16805 ROAD 19%

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PLATTEVILLE, COLOR ADO 80651 1

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.- 3 9 Mr. Karl V. Seyfrit, Director Nuclear Regulatory Commf ssion Region IV of fice of Inspection and Enforcement 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76012 Reference: Facility Operating License No. DP R-34 Docket No. 50-267

Dear Mr. Seyfrit:

Enc'.osed please find a copy of Reportable Occurrence Report F 50-267/

81-024, Preliminary, submitted per the requirements of Techn ecifi-cation 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. 50-267/81-024.

Very truly yours, YWu Q

Don Warembourg

!bnager, Nuclear Production DW/cis Enclosure 0

cc: Director, MIPC s

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8106030o'l$

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OCCt'UINCE PIPORT SitTRISt,T!0N Nueber of Cootes Department of Energy - <

1 (P Letter)

San Francisco Operationa Of fice Atta C411f 3rnia Patent Orcup 1333 3 roadway Oakland, California 94612 Dep a r tmen t o f Ene rgy - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

1 (P Letter) ltr. Glen A. Newby, Chief 471 3 ranch Division of Lelear Power Development Mail Station 3-107 Vashington, D.C.

20545 De par tme nt o f Ene r gy - - - - - - - - - - - - - - - - - -.. - - - - - - - - - -

1 (P Letter)

Acts: Project Manager 110 Vest A Street. Suite 460 San 3teso, California 92101 Mr. Karl v. Seyfrit, Director 1

(Original of P Letter Region IV y and Copy of LZ1)

Of fice of Inspection and Inforcement Nuclear Regulatory Commiselon 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76012 D i re c t o r - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

1 (P Letter, LER)

Of fice of Management Inforzation and Program Control C. 3. Nuclear Regulatory Commission Washington, D.C.

20553 Mr. h en a r d Phe lp s -

r. - - - - - - - - - - - - - - - - - - - - - - - - - - - 10 (Original of MLG Letter FS7, 2, Site plus Two Copies. One Rep rese ntative Copy of P Letter One Oeneral Atomic Company copy of Lgg)

P. 0, 3ox 426

?lattaville, Colorado 30651 M r. S i l l Lava le s - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

1 (P Letter, LER)

Nuclear Jafety Analysis Center 3412 Itt11 view Avenue

?. O. Box 10412

?sio Alto, California 74303 NRC Resident ilte Inspector 1

(P Letter, IIR) pggt BR$ln

REPORT DATE:

April 16.1981 REPORTABLE OCCURRENCE 81-024 ISSUE O OCCURRENCE DATE:

March 17. 1981 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNIT ROAD 19 1/2 PLATTEVILLE, COLORADO 30651 REPORT NO. 50-267/81-024/03-L-0 Preliminary IDENTIFICATION OF i

LCURRENCE :

During the March performance of the monthly check of the helium circulator i

seal malfunction pressure differential switches, it was discovered that five of the twelve switch units tripped outside the limits specified in LCO 4.4.1 Table 4.4-3.

These are reportable per Fort St. Vrain Technical Specifications AC 7.5.2(b)1 and AC J.5.2(b)2.

EVENT

DESCRIPTION

On March 17, 1981, while operating at 69% thermal power and 220 MWe elec-crical, instrument personnel performed the circulator seal malfunction (buffer-mid-buf fer) 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 has been 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 ele-ment 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 vator (negative buffer-mid-buffer), and the other electrical switch must operate at less than or equal to (+) 80 inches of water (positive buffer-mid-buffer) per Table 4.4-3.

The trip settings for the twelve switches are listed in Table 1.

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

DESCRIPTION

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

l l

O O

REPORTABLE OCCURRENCE 81-024 ISSUE O Page 2 of 4 CORRECTIVE ACTION:

The trip settings of the electrical switches wert-re-adjusted to the proper trip points and the test satisfactorily completed.

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

The investigation of the proble:n associated with the helium circulator seal malfunction trip switches has been completed, and Public Service Company Nuclear Project Department is proceeding on a path to replace the existing equipment.

G 1

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REPORTABLE OCCURRENCE 81-024 ISSUE O Page 3 of 4 TABLE 1 Am Found Inches H30 As Left Inches H30 Increasing Decreasing Increasing Decreasing Trip Point Trip Point Trip Point Trip Point 1A Circulator P DIS-21149

+90(1)

- 14(1) 75

- 5 PDIS-21151

+ 75

- 15(5) 75

- 6 PDIS-21153

+ 74

- 9 74

- 9 13 Circulator PDIS-21155

+ 69

- 5 73

- 5 PDIS-21157

+100(5)

- 5 73

- 5 PDIS-21159

+ 73

- 5 73

- 5 1C Circulator PDIS-21150

+ 78

- 17 (5) 78

- 3 PDIS-21152

+82(5)-

- 40(5) 75

- 5 l

P DIS-21154

+ 75

- 3 75

- 3 1D Circulator PDIS-21156

+ 74

- 5 74

- 5 PDIS-21158

+ 74

- 6 74

- 6 PDIS-21160

+ 75

- 7 75

- 7

(

Denotes Switches which were out of tolerance.

i 1

1

REPORTABLE OCCURRENCE 81-024 ISSUE O Page 4 of 4 Prepared By:

Reed 22 Asa B.

Technical Services Technician Reviewed By:

WT Gahm echnical Services Supervisor Reviewed By:

NA Frank M. Mathie Operations Manager Approved By:

7TmM _

Don Warembourg

/

Manager, Nuclear Production l

2

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