05000029/LER-1985-010, Forwards LER 85-010-00 Re Inadvertent Reactor Scram During Maint Activity

Forwards LER 85-010-00 Re Inadvertent Reactor Scram During Maint Activity

ML20137T930
Person / Time
Site:	Yankee Rowe
Issue date:	01/27/1986
From:	St Laurent N YANKEE ATOMIC ELECTRIC CO.
To:	Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
NUDOCS 8602190011
Download: ML20137T930 (1)

LER-2085-010, Forwards LER 85-010-00 Re Inadvertent Reactor Scram During Maint Activity

Event date:
Report date:
0292085010R00 - NRC Website

text

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YANKEE ATOMIC ELECTRIC COMPANY vm Rowe, Massachusetts 01367

~ e January 27, 1986 U.S. Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, Pennsylvania 19406 Attention: Dr. Thomas E. Murley, Regional Administrator

Subject:

Licensee Event Report 50-29/85-010 Inadvertent Reactor Scram During Maintenance Activity

Dear Sir:

In accordance with 10 CFR 50.73(a)(2)(iv), the attached Licensee Event Report is hereby submitted.

Very truly yours,

$kY4 (LLL Normand N. St. Laurent Plant Superintendent ELM /nm Enclosure cc: [3] NSARC Chairman (YAEC)

[1] Institute of Nuclear Power Operations (INP0) 8602190011 DR 860127 g ADOCK 05000029 PDR

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• Nace. Ease u s. NuCLEma (EcutATOIv Commission M3I AP*ROYED OMS ho 3190.4104 LICENSEE EVENT REPORT (LER)

DOCKET NuMSER 12) FAOEsh FACILITY NAME 81)

YANKEE NUCLEAR POWER STATION, ROWE, MASSACHUSETTS o l5 ] o lo [ 01012l 9 1 loFl 0! 2 TITLE les INADVERTENT REACTOR SCRAM DURING MAINTENANCE ACTIVITY REPORT DATE (71 OTHER p ACILITIES INVOLVED ISD EVENT DATE ISI LER NuweER ten VEAR F ACILeT v N AW65 OOCnE T NuMsER:Si MONTH DAY YEan VEAR VONTM OAY 0f510I0I0 t t I J2 2l 8 8 5 8l5 0l 1l 0 0l0 0l1 2l 7 8!6 015t01010t!I TMis mEPOa7 is suomiTTED PunsuaNT TO THE mEOuinf uENTs 0,10 Can 4 iCa.c. .< ,. ., ca. i.u.-,, citi N'W 20.402th) 20 A06fs) X S0 73deH2 Heel 73.71148 20.40GleHilf4 80 381s1111 50 731sH2Het 73 71(al m

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On December 23, 1985, at 1329 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.056845e-4 months <br />, with the plant in Mode 2 and at 10 ' amps reactor power, an inadvertent reactor scram occurred as a result of a functional test of an intermediate range nuclear instrumentation channel, using an approved procedure. The reactor protection system high startup rate (SUR) scram logic, which is cut in below 15 MWe, was completed by a faise signal initiated dur'ng the performance of the function test by Instrumentation and Control Technicians. All i plant equipment responded correctly. A four-hour notification, pursuant to 10 CFR j 50.72.b.2.II, was made to the NRC at 1415 hours0.0164 days <br />0.393 hours <br />0.00234 weeks <br />5.384075e-4 months <br />.

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The root cause of this occurrence was attributed to personnel error. The appropriate plant personnel will be counseled to consider the effect of their actions at all times. The plant procedure OP-4601 will be revised to clarify the high SUR scram precautions and a new prerequisite added.

i l There was no adverse effect to the public health or safety as a result of this occurrence.

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NRC Form 364A U $. NUCLEJ.R R:EGULATOMY C094555iO%

- LICENSEE EVENT REPORT (LER) TEXT CONTINUATION maovf o cu2 =o 3 so-o'o*

EXPIRES 5/31/3}

FACILITY NAME Ill DOCKET NUMBER (2) LER NUMBER 163 PAGE 131 YANKEE NUCLEAR POWER STATION vs.R n = p,*, ' qva;;

ROWE, MASSACHUSETTS YEXT IW more soace a requeed, use sehtoonalhRC form 3ti6Ks)117) ol5lol0l0l0l2l9 8l 5 -

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On December 28,1985, at 1329 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.056845e-4 months <br />, with the plant in Mode 2 and at 10 ' amps reactor power, an inadvertent reactor scram occurred during the performance of procedure OP-4601, " Nuclear Instrumentation Channels Functional Test" for Channel 3 Intermediate Range Channel. A four-hour notification, pursuant to 10 CFR 50.72.b.2.II, was made to the NRC at 1415 hours0.0164 days <br />0.393 hours <br />0.00234 weeks <br />5.384075e-4 months <br />.

In response to a Maintenance Request for Channel 3 the Instrument and Control (I&C)

Department Foreman dispatched two I&C Technicians to the Control Room to perform procedure OP-4601 on Channel 3. Using OP-4601, an approved plant procedure, and with the knowledge of the operating shift personnel the I&C Technicians started the procedure which resulted in the initiation of a reactor scram from the intermediate range neutron flux high startup rate (SUR) scram signal.

The intermediate range neutron flux high SUR 1 of 2 channel scram logic is automatically bypassed at greater than or equal to 15 MWe and is automatically cut in prior to going below 15 MWe. The I&C Foreman failed to adequately consider the existing plant conditions and all the ramifications of performing OP-4601 while in Mode 2. The precaution and note in the procedure which refers to the high SUR trip are difficult to comprehend and were thus missed by the I&C Technicians.

The I&C Foreman and Technicians and Operators will be counseled to consider the effects of their actions at all times. The plant procedure OP-4601 will be revised to clarify the high SUR scram precautions and a new prerequisite added.

This is the first reportable occurrence of this nature.

There was no adverse effect to the public health or safety as a result of this occurrence.

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