ML19350A166

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AO 50-29/74-3:on 740627,during Refueling Interval Surveillance Testing of Pressurizer Pressure Channel,Low Pressure Scram Setpoint Found Below Tech Specs Limit.Caused by Instrumentation Drift.Scram Setpoint Readjusted
ML19350A166
Person / Time
Site: Yankee Rowe
Issue date: 07/05/1974
From: Autio H
YANKEE ATOMIC ELECTRIC CO.
To:
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
AO-50-29-74-3, NUDOCS 8102120187
Download: ML19350A166 (1)


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AB:!ORV.AL OCCURRE'iC.: REPORT REPORT NU"3ER:

50-29/Th-3 REPORT DATE:

July 5. 197h OCCUURD:CE f*TE:

June 27, 197h FACILITY:

Yankee Atomic Electric Company, Rove, Passachusetts 01367 IDCIFICATIO'; 0F OCCURRE?CE: Protective Instrunentation Setooint Dri.

CO!TDITIO' S PRIOR TO OCCURRENCES: Refuelind Shutdown, Shutdown Cooling Systen Operating, Reactor Coolant Tennerature at 1000F.

DrCCDIM'IO!! OF OCCURRUTCE During routine refueling interval surveillance testing of the pressurizer pressure channel, the low pressure scra: setpoint was found to be at 1780 psig.

This is a violation of the Technical Specifications Appendix A, Section D.2.d.1 and Table 1 which lists a minimum setpoint of 1800 psig.

DPSIGNATION OF'ADPARENT CAUSE Or OCCURRD!CE Inctru~.entation drift; setpoint too close to the Technical Specifications linit.

A':ALYFIS OF OCCURRE'!CE The pressurizer pressure cMnnel is one of two channels, the other be!ng the

=ain coolant pressure channel, capable of scranning the reactor in event of a low pressure condition. Surveillance testing of th. main coolant presrure channel perforned three weeks _ earlier showed the low pressure scran setpoint to be within linits. Therefore had a low pressure scra-Fondition occurred, the reactor would have been scra.:med prior te exceeding t :c Technical Specification li=it..

'Cso, the YAEC Safety Analysis, FHSR Section h00, lists a trip setting of 1759 psig used during the Transient Analysis. This setting is 21 psi less than the out-of-tolerance value.- It could therefore be concluded that no additional risk to the health and safety of the public vould have occurred had the reactor been scramned at the out-of-tolerance limit.

' CORRECTIVE ACTIO!I TheLlow pressure ~ scram sett iint was readjusted toi1830 psig to allow fo.-

instrumentation drift with'at exceeding the Technical Specification limit

of 1800 psig.

. FAILURE DATA NA

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_y/oa/ao /r7 Lt riant Superintendent.

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YAll!iEE ATCDie E!.: 370!0 COMPAliY

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YNidM, Juiv 5, 1974 gb i

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United '.,es Atomic Energy Consission i

Directorate of Regulatory Operation Region 1 65] Park Avenue 19406 A.O. 74-4 King of Prussia, Pennsylvania Pursuant to the requirements of Technical Spec-ifications', Appendix A Section B.2 refering to Section 106 of the Final liazards Sumnery Report, a chemistry licit for Shutdown Chemistry was exceeded.

During ch$mical sanpling of the shutdown cooling system for clorides on 7/2/73 the Technical Spec-ification of 40.1 pp;n clorides for cold shutdown chemistry was exceeded.

The clorides reached a maxinun of 0.12 ppn.

The Ion Exchange capsule indicated that it was and another capsule was put into service on the afternoon of 7/2/74.

Cloride levels were reduced to spent

<0.1 ppa by 0100 on 7/3/74.

Very truly yours, f

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Herbert A. Autio Plant Superintende'nt liAA/mid e

76/ Mo6ff

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