ML21133A266

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Us Dept. of Commerce, National Institute of Standards & Technology, Follow-Up to Event Report
ML21133A266
Person / Time
Site: National Bureau of Standards Reactor
Issue date: 05/13/2021
From: Newton T
US Dept of Commerce, National Institute of Standards & Technology (NIST)
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
55120
Download: ML21133A266 (2)


Text

1 of g A a

UNITEDSTATESDEPARTMENT OFCOMMERCE l

National institute ofStandards andTechnology

, 9/ Gaithersburg, Maryland 20899-b4TIS OS May 13,2021 Document Control Desk U.S.

Nuclear Regulatory Commission Washington,DC 20555-0001

Subject:

Follow-up toevent report Ref:NRCEvent Report

  1. 55120, Docket 50-184,Facility License TR-5 Sirs andMadams:

OnMarch5,2021, theNCNR(NIST Centerfor Neutron Research)submitted areport of exceeding asafety limit ontheeventofFebruary 3, 2021 (original EventReport

  1. 55094).

Inresponse totheevent, weinstituted aninvestigation into therootcauses andhave uncovered evidence tosuggest that there wasanunlatched element inthecoreprior to reactor startup onFebruary 3.Theinvestigation has identified inadequacies inthe implementation ofadministrative andprocedural controls.Specifically, these inadequacies areasfollows:

1)training andproficiencies infuel

latching, 2)procedures infuel movementsandlatching, 3)enforcement ofprocedural compliance 4)implementation oflatch verification
methods, and 5)management oversight ofrefueling staffing Accordingly, wereported this bytelephone totheNRCHeadquarters OperationCenter onMay6,2021andaresubmitting this 14-day report inaccordance with NBSR Technical Specification 6.7.2(1)(g).

Inaddition, inaccordance with reporting requirements inNBSRTechnical Specification 6.7.2(1)(d) wehaveidentified that theintent ofthefollowing Limiting Conditions for Operation wasnotmet:

TS3.1.3 Thereactorshall notoperate unless allgrid positions arefilled withfuel length fuel elements orthimbles, exceptduring subcritical andcritical startup testing withnatural convections flow.

Eventhough itwasbelieved that this specification wasmetonFebruary 3,2021 prior toreactor

startup, subsequent investigation found that anelement inposition J-7wasoutofthelower grid plate.

Itisnowpresumed that this element wasout ofposition prior toreactor startup.

e TS3.9.2.1.

"Following handling offitel within thereactor

vessel, the reactor shall notbeoperated until allfuel elements that havebeenhandled areinspected

todeterminethat they arelocked intheir proper positions inthe coregrid structure.

This shall beaccomplished byoneofthefollowing methods:

(1)Elevation check ofthefuel element with mainpumpflow.

(2) Rotational check oftheelement headinthelatching direction only.

(3)Visual inspection ofthefuel element headorlatching bar.

After therefueling onJanuary 4,2021, therequired rotational checks were completedand signed off.

However, theinvestigation following theFebruary 3

event showedthat these checksweredoneincorrectly, andthus didnotmeetthe intent ofTS3.9.2.1.

Please feel free tocontact meif you haveanyquestions.

Respecllysubitted,

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ThomasNewton Deputy Director andChief ofReactor Operations andEngineering NISTCenter forNeutron Research