05000245/LER-1982-025, Forwards LER 82-025/03L-0.Detailed Event Analysis Encl

Forwards LER 82-025/03L-0.Detailed Event Analysis Encl

ML20028B721
Person / Time
Site:	Millstone
Issue date:	11/24/1982
From:	Mroczka E NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20028B722	List: 05000245/LER-1982-025, Forwards LER 82-025/03L-0.Detailed Event Analysis Encl 05000245/LER-1982-025-03, /03L-0:on 821026,pressure Switch 263-55C Tripped Above Tech Spec During Reactor Vessel High Pressure Functional & Calibr Test.Caused by Setpoint Drift.Switch Reset & Satisfactorily Tested
References
MP-4404, NUDOCS 8212030180
Download: ML20028B721 (2)

LER-1982-025, Forwards LER 82-025/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2451982025R00 - NRC Website

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November 24, 1982 MP-4404 Mr. Ronald C. Ilaynes Regional Idntinistrator, Region I Office of Inspection and Enforcenent U.S. Nuclear Pegulatory Camission 631 Park Avenue King of Prussia, Ibnnsylvania 19406

Reference:

Provisional License DPR-21 Docket No. 50-245 Reportable Occurrence RO-82-25/3L

Dear Mr. Haynes:

This letter forwards the Licensee Event Report for Reportable Oc.currence lo-82-25/3L required to be subnitted within thirty days pursuant to the requirements of the Millstone Unit 1 Technical Specifications, Section 6.9.1.9.a.

An additional three copies of the report are enclosed.

Yours truly, NOIGIEAST NUCLEAR D4ERGY C04PANY w

E.

. Mroczka Station Superintendent Millstone Nuclear Power Station E]M/TST:mo

Attachment:

LER RO-82-25/3L cc: Director, Office of Inspection and Enforcement Washington, D. C.

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Director, Office of Management Informatica and Program Control, Washington, D. C.

(3)

U. S. Nuclear Regulatory Cmmission, c/o Document Managcment Branch, Washington, D.C. 20555 8212030180 821124 PDR ADOCK 05000245 S

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e ATTACHMENP 'IO LER 82-25/3L NOmHEAST NUCLEAR MERGY CmPANY MTTLW NUCLEAR POWER STATIN - UNIT 1 PROVISIWAL LICENSE NUMBER DPR-21 DOCKEP NUMBER 50-245 IDENTIFICATION OF OCCURRENCE Reactor vessel high pressure instrument setting was found to be less conservative than that established by Technical Specifications.

CWDITIONS PRIOR 'IO OCCURRENCE Prior to occurrence the unit was shutdown for a refueling outage.

DESCRIPTICN OF OOCURRENCE On October 26, 1982, at 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br />, while performing Reactor Vessel High Pressure Scram Functional and Calibration Test, pressure switch 263-55C tripped at 1100 psig. Technical Specifications, Table 3.1.1 requires a high reactor pressure trip level setting less than or equal to 1085 psig. 'Ihe switch setpoint limit is 1098 psig.

(1085 psig plus 13 psi head correction).

APPARENT CAUSE The failure of this switch to trip at its desired setpoint was attributed to setpoint drift.

ANALYSIS OF 00CURRENCE The switch in question is one of four switches arranged in a one-out-of-two-twice logic system that initiates a reactor scram. Failure of one of the switches to trip at the desired setpoint did not impair operability of the system. 'Ihe ranining switches were found to be at the proper setpoint and would have initiated the required action upon receipt of a reactor vessel high pressure. Therefore, no safety was emprmtised.

CORieL:nVE ACTIm l

The pressure switch was reset to its required setpoint and satisfactorily tested.

The switch is a Meletron Model No. 372 with a range of 28 to 1400 psig.

Similar occurrence: 80-09/3L.

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