IR 05000346/1990014
| ML20059A667 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 08/09/1990 |
| From: | Knop R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20059A664 | List: |
| References | |
| 50-346-90-14-EC, EA-90-109, NUDOCS 9008230165 | |
| Download: ML20059A667 (32) | |
Text
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.,' p q ~' U.S. NUCLEAR REGULATORY COMMISSION I L' l
REGION III
Report No.150-346/90014(DRP) j EA % 139 r i ' License No.-NPF-3 Docket No. 50-346-Licensee: Toledo Edison Company
Edison Plaza L 300 Madison Avenue: Toledo, OH 43652 Facility.Name: Davis-Besse Nuclear.F.Jer Station Meeting At: Region III.0ffice, Glen Ellyn, Illinois Meeting Conducted::. June 1,.1990 ~ Type of Meeting:- ' Enforcement Conference-Telephone Enforcenient Conference Date:. July 17, 1990 Inspectors: 'D..E. Miller P.'M.
Byron-j Approved By: S MW O ul' R. C. Knop, Chief ' Data ' - Reactor Projects Branch 3 Meetina Summary . Meeting on June 1, 1990, and a telephone enforcement conference on July 17, 1990 (Report No. 50-346/90013(DRP), Matter Discussed: 1; Apparent violations of technical specification and 10:CFR 50 Appendix B E requirements involving potential for overexposure during core support assembly o y lift activities; inadvertent draindown of the refueling; canal;.an' Emergency' . Core Cooling System injection; steam generator overfill; two occurrences of a i . decay heat valve misposition; an inadvertent decay heat system pressurization;. and inadvertent shutdown of the wrong make'up pump.
Information pertinent-to the causes, safety significance, and corrective actions for these events were - discussed.
Disposition of the apparent violations will be-presented in subsequent communications.
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.e . , ,, t i* +9'+i, . M ._ , , i ' 1 j i _., F L1'.j i eetina' Attendees ' a % S" Toledo Edison Company ' ' ' ~ , n .v.
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+ . w' ' N M. Bezilla, Cperations Superintendent, j- . .j '
- R. Gaston,: Licensing Engineeru
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, l1 %'.O ~*G. Gibbst-Director, QA' _ ' , jr D.;Imlay, Shift; Supervisor. t ' ' g +. _ < ! W. Molpus? Shift. Supervisor, .., , ' y
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E , J.JPolyak, Manager, Radiological: Control " Y
4 .. ..R. Schr'auder, Manager, Nuclear licensing ' .-l '
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- D JSchreiner,-Op'erations Assessment Supercisor'
. ' . ji ' , E D. Shelton.Vice President, Nuclear.(Centerior Energy) E + 7}. , ,. ' L*L. Storz,; Plant Manager .p
' e .s . . . . .. +. ,m u ,~ Nuclear, Regulatory' Commission-y y , , . , , , !. - . . , . ., , ma '! > - JLBPBerson,-Region:l" Counsel ~' .,; 4 - >' - r K *P.i Byron, Senior. Resident Inspector ' ~~ ' - ' '! ,_ L
- A.? Davis,yRegionalAdministrator.
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. 'E "*Af Dunlop,t Project Engineer . . . .. , t ' ' - "g^/ A W. Forney, DeputysDirector, Division of Reactor Projects i ,:
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L. Gregerr Chief,; Reactor Programs Branch l: m' [. y J. Grobe, Director'of Enforcement,.RIII, /,y 's '4 , i c
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H+ N.1Jackiw, Chief,tReactor1 Projects'Section 3AL - t ' , " ' L
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- R.' Knop DChief, Reactor Projects Section 3
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<l ' r . , lj i, " cD.JMiller,! Senior RadiationcSpecialist -
,r s s , i/A ,... ' C C. NoreliusLDiiector, Division of Radiation Safety andtSafeguardsuSection' 1/ d <. lT '7^ I i ;*M.' Schumacher, Chief, Radiological Controls' and ~ Chemistrf: Sect,16n N ~ q Ie f' y ., t
- W. Schultz hEnforcement'and' Investigation Staff W7 sF
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- T.. Wambach,'. Project Manger, NRR PU W 7
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. Enforcement"Conferenc'e Details.
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, r WD .'As a2 result ofl. identification. of ' apparent sihnificant violationsiof,NRC ,O.
i i , regulatory, requirements., an enforcement conference was hel Lin the'NRC M " a l
, ,- % ' Region III office'on June 11,11990. The' preliminary. findings', which were; j ' - > m J the base's for these app'arent" violations, were documented in-NRC: ,e 'FH < Inspection"Rebortl No. 50-346/90012(DRSS), and 50-346/90009(DRP).f A1, ) 1 V,' j ' ' supplemental teleconference was held onl July 17, 1990,ito discuss 1the-W, w J'
> L ;"3' ' appa'rentfviolationsldocumentedlinNRRInspection' Report 50-346/90013(DRP).' # ,J
9 TheLattendeesfat:this-enforcement, conference are 1isted in Section:1:above.
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- g'J Th'e NRC Region'III: staff summarized lthe inspection; findings,LapparentL
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violation' of' regulatory' requirements, a'nd other regulatory concerns; s , i 'i 1The; concerns. discussed by the Region IIItstaff includedith potentialc r ' + "' / > fort overekposure;during;handlin'g of the. Core Support Assemblyi(CSA) ton. , , April 125,11990,fand the refuelingLcanal! draining event'on/Mayil,m1990a w The primaryTreason for the enforcement conferenceLwas'to obtain
~ Vi 'm e m F bc" additional;information from the licensee regardingethe events and the M.
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apparent violations.
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y ,, , ,~ ( , , .) ,,. N^ Core Support Assembly Event , ,, , , Licensee-' senior.ma'nagement described the sequence of events' surrounding , the CSA liftf the management ordered: investigation and its conclusions, ' lessons learned, including root causes and contributing factors, and:
, corrective: actions underway,and planned.. The licensee's: description of the event'was very similar to the j w c description in'NRC Inspection Report No. 50-346/90012(DRSS)..(One:. j . , ,
- significant difference was that the license's post-event reconstruction
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- i-ashowed'there was ample' clearance to' allow the'CSA to follow the same
, path during the April'25, 1990. transfer as during the March 4, 1990_ y',
transfer.
Thus thefadditional' lift height on April-25,-1990s aad the
2 attendant: personnel dose increases,were unnecessary.
This finding l ' + 1, underscored the predob planning weaknesses,- particularly the absence of-j A i the lift specialist, and;the =need for a method ~ of reliably knowingLthe'- 'l .. adequacy.of clearance beneath the CSA without having to rely solely on-t the visual judgement of the lift specialist.- ' ' ' " ' ' c , <
3 ' There was also a' difference.in: understanding between the-licensee and the- - region as to'how high the:CSA was'actually lifted from'the water during-f e / w', ' . -t, the" April 25, 1990 transfer.
A licensee Independent Safety Engineering- .+ , , (ISE) assessment. concluded that it was lifted to a' point;where the co'e - v ' c - ' barrel bolt ring ~was 123to 18 inches above the water, whereas the 41' 'llicensee's' original assessment was somewhat lower and more consistent i ' -
~, i _ ith;thefinspectorst? understanding derived from his discussion with i " a w , -
t participants. JThe'ISE estimate was based on examination ~of,the radiation
',i j monitor charts and the rate'offlif t by1the polar crane, whereas' the %* s . ' d ' , , licensee's original assessmenttwas' based primarily' on individua'l t d w ,
- recollection'after the occurrence.
This difference-has significance. ' - - - [, ybecause iit affects the' potential zdo'se rates, and associatedfpersonnel'
1 *p doses,s.had thesCSA been'11fted'further out'of the water. 5 The-licensee ' i g ' , ' ' y~+- concluded from its evaluation that-a significant potential'foPan, i ' ' u N overexposure did not existi particularly when:the~ prompt acti6nslVthat-
i , . , were'taken'by the radiological control < technician are considered.
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' ,i. , . - '. : '91 ' _ ,, p4 V License ^ management offered an in-depth analysis of the event 4 including i _ ' J p . causes and contributory, factors, which was basically? unchanged fromTthat-g in the referenced inspection report.
The licensee's evaluation.:... ', ' W emphasized the absence of.a reliable method of determining.CSA bottom + -. clearance'as the root cause,.'whereas, Region III stressed the inadequacy
, i of. preplanning as the more fundamental. root cause. -The; difference in -l e
, ._ t l; emphasis does notl appear,significant, particularly since the licensee i > ' . ,f corrective actions' address both concerns.
' ' e , I The'llcensee described corre'ctive actions which have been or will be- }implementedinresponsetothiseventinclude:
, , , Provideamore.effectivemeansof,verifyingclearancebetNeenthel + - !' .CSA 'and the, refueling canal floor.
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that any abnormal conditions can be carefully eval ' , n
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'Developseparateradiation'wofkpermitswhendealingwithlmultiple" . . . , ' .L; ' _ < u - components with varying radiological control requirements! ' i . ,, ,j f, ', s. . g,jm ~ o - n Require!a; formal ALARA b iefing with'a11[ key personnhlsprior td s{ , ' 'i major evolution.
- j I ' 4 '3 A ' * . RequiretheShiftSupervisor,;RadiologicalContN]1 - ' 'M<c, , and ALARA-briefings for all;ma'jor, radiological evbl ufervisorf and!' o g" ' q o,. -m
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'oversightandcontrol.ofmajorcontractedtaskRequire-y,. f , .., ,. . my a . /
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< clearly understand who is-the single person.at all particip in chargei , The senior NRC representatives ac~ knowledged the licensee's pres g " and stated that the -licensee would be notified in writing of'the NRC' . on decision regarding enforcement: actions based on ~the inspection fi di . n ngs.
_ Refueling Canal Drainina Incident 1 , " refueling canal draindown:that occurred on'AprilLicense r . . >
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30, 1990c y The plant was in the process of draining'the refue
. - 't g - ' The indexing fixture, used to properly' align ~the . ~ during the installation, was stil1 ~in place over: upper plenum ~ assembly indexing; fixture. sits on the reactor vessel flange)and extends;to-the ' reactor vessel.
The .approximately 6~ feet above the; vessel flange. ;The drain <flowpath;was' Storage Tank (BWST). ~The initial drain: rate wasil50 ",
a er in~ service on the Reactor Coola.nt System'(RCS).
'DH pump 2;was' . "W, , ' The Containment Coordinator was ~ assigned the task-of watching the y~ refueling canal level locally-and informing;the Operators'when there w . s '~ 6 inches in the refueling canalb A Reactor' Operator wascalso watchi s the refueling canal level indication in th . ng this level decrease to the level increase'e Control: Room and: comparing l - in the;BWSTn '^ w
When the refueling' canal level decreased to: approximately 5' feet,the , [ . reactor operator noticed that the reactor-Vessel level was still'. . . " decreasing,'but'the refueling. canal level.-had stopped' decreasing , , , same' time the Containment Coordinator called and saidithat . .; At level was going down without'a decrease'in the canal level.
, a ,0perator decreased DHJflow and stopped the OH pump:which was be The Reactor . 4m A
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By the-time the pump was stopped, approximately 1. foot,of- ' + - > ~ ' ~ the upper plenum assembly,had become uncovered.
The flange-to-flange. fit: , . of the indexing fixture to the reactor vessel was tight'enough that at ~ '
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- sthis flow rate not enough leakage by5the flange 1existedito allow the
. ' ca.nal to drain along with the reactor vessel.
- * - , . i ' .. , . ' Upon being informed of=the problem, the Padiological. Controls Foreman 1
' - removed personnel from the area of the refueling canal and; surveys were- ) ' performed.
The1highestireading was approximately 130 mR/hr at the west -! - walkway-above the reactor vessel.
There were no indications of any
- 1' increased exposure'to personnel.. - , ' , t e , . '
Operators then lined.up to gravity fill the reactor vesseltfrom the BWST.
' which took-approximately 7 minutes.L At no._ time'was decay heat flow lost G nor. decreased.
Additional detail of this event is provided in1Inspectio.n ,. , ' b Report No. 50-346/90012(DRSS).. . '~
, , Following the evaluation summary and sequence of events presentation, ' licensee representatives continued with their discussion of; root cause determination and finally with their corrective actions taken_to prevent', ,J
trecurrence ofithis event.
?4 , During the Enforcement Conference ~,ithe licensee also? generally discussed - I; * l other incidents that had occurred during the refueling outage..>With y regard to the; core support a sembly> event, the refueling canal draindown, -and the other recent events,' licensee management acknowledged that' u > r l collectively these incidents demonstrate management;and operational 91 - L deficiencies.
The licensee's overall corrective actions were'to ' ' L , individually evaluate and assess the corrective' actions; reemphasize;the' i importance of proper communicatic'nsp impleinent:seniorroperations' ~ , < n l management coverage; impose a work / testing stoppage; andiimplement.a s .
, "go: slow" philosophy., Theilicensee also described their' implementation L ' ' i l' ' of the " POWER!' program-for the operations department. The program will i , I L emphasize professionalism (P),, ownership;(0), work qualitys(W), J '4 excellence (E), and responsibility-(R)4- ' f.
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. At the conclusion of the enforcement' co_nference, senior"NRC" .. s / - l . ' . .a representatives acknowledged the: licensee's representat' ion and stated that
l/! / the resident staff would continue to review the'recent 16cidents and'that; i , - s " _U
the licensee would be notified'in writing of the NRC' decision rega'rding:' ~ ' ' [M] ,s_ enforcement actions.
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' + > +p s 't v Subsequent to the enforcement conference,;on. July 17,c1990; a, , s ' ~ " ~ .eteleconference was held With the Davis-Besse1 Plant Manager and members ofs - b Yhis ~ staff to discuss:the result's of;the NRC's investi'gation;into " l l ,
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, up pump shutdown which are described in;In~spection Report No. '
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' , 50-346/90013(DRP). The.NRC' stated that enfo'rcement: action remains un^ der! consideration'as airesult of'these events. f4 , , %i s k-e ' , "
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, . , - . . , I p , J ' ', e 4- , , , - g < - - , , \\ , . ' . > i 1 . . ,. m The NRC acknowledges the licensee's June 21, 1990Linitiative.to; suspend-. . plant, heat up following the identification of'an increase in plant events s $\\- related to operations. performance. The NRC'also notes the licensee's . El , ' ?> aggressiveness in initiating an independent ^ review of their operations-
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CON FEREN.CEL . W JUNE 1,1990: . 1( b i .a t t , ' s
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AGENDA g l ! ' . Introduction ' . CSA ' Lift . Refueling Canal Drain Down =.; j .1 'l l ) .l . L-l , . l-l > 'l I ....._.._..._..,..,......_.,.____......-..._._._._.........._.........1 , , _, _ ,, _,...., _ _ . . f. ...
.. ,, CSA Lift e Evolution Summary , I ! i e Sequence-of Events . e Management Reaction ! e Conclusions ' i e Root Cause - , e Contributing Factors j ., o Corrective Actions a P l ' l l 1- ~
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i o Reactor core barrel 1was beingl lifted , / and: transferred to the reactor vessel
in preparation for core: refueling
-r e CSA was lifted higher than planned
resulting in an additional' exposure of
" approximately 2.5. man-Rem , e Timely evacuation -of personnul from - the immediate area occurred' . , h i i ' -p --, i
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' l ~ . _ . . ... - - - - - -. - - - .. - - -.. -. - - . . . . ,. ... .t . a . J-CSA' Lift - SEQUENCE OF EVENTS ' 04/25/90 , i - e At-approximately.1530;- Pre-Job Briefing / ALARA Briefing
I 'e 1800 - Latched CSA to: the Rigging-Assembly - e 2030 -rBegan, moving CSA.from!theLdeep end of' i refueling : canal to the ~ Reactor-. Vessel "
.. . . m) - e Lift Specialist directed crane. operator to. lift lCSA to clear: obstructions in shallow? end'of. canal' e Dose. levels increased-toL5-6 R/Hr in general _ area , t(approximately two minutes)
~e HP technician observedt high Lradiation levels and-l ." directed personnel. to' clear; area ((Southeast: end of
' ' Refueling Canal)
e. Radiological Control directed the: LiftiSpecialist to [ lower the-CSA to' reduce dose rate j e Lift-Specialist directed CSA to' be.' lowered after. - , clearing-obstructions.- ! e CSA traversed and lowered into Reactor Vessel l i l i .. -.a- . . - -. - - -. -.. . =.. . . -. ... -.... .. =. . .. _. - -.. . ..... . ~ ~ _ . - -- 13._. .. - _ . , . . FUEL. TRANSFER --- SYSTEM
HOSES - ' TRASH CAN'IN THIS' RACK - , RX , 3O i . ] l ,
. . . 26'. - 17' -6" = = = = . ti EL. 603' i __ - - - _.__ - n < - n . ~- - _ _ _ " TRASH CAN --
! FUEL ASSEMBLY.- !
23' -6' '25' RACKS ~ ! a H95ES-i f u EL. 578 u d-53' ' , , i. - l ..
i CSA - i ' s; , 1-CSA. l
K _j ~ '. STAND j y_ RV _ .. EL. 550' -6" U-i. ___-w._ ~. _ - . .... ~ , _. _ _. _. _. -, ..m...,.__. _., f l. ~._ . _.., _. _ _ _. _ _.. -_ _ _ _. _, _ _., _ _ _ _. _ _, _ _ _ _ _ _ _. _,. _...., _ _ _ _. _.. _. ., ,,, _ _., .. . ..._ ... -. - , . _ _ _ _ _ _ _. _. - _.. _. _.... __ _ _ _..
-d I ' . Cont SLT'WT AS$DitLY '-
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C . ., , ,, M.m. Wat.r Level During / - O Transf.r From Rs
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._ __ . __ __ ___ _ -__. _ _ - _ _ __ __ _... _ O,, TI $ Pot tJ -i Wa t.erLev.1 if , wy, nott Ring to 13" au , , , , ,,, ,,,, ,,,, ' m Above Idn t.t ' , ,,, , , .. .- - Top o Active ! - ' root aest.n i1 -- fl = . , . ... ..:... ',. v i- - - . ... . .- , < , , A ' - - .... ..-.. e i s I~ I ' , W : - ..... ... . - - , , .} N
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- e + - - - - r.. .-.,,a. - - - -,. - >.,. ' . . p q > ... +.. l CSAllift L MANAGEMENT REACTION eimmediate critique produces Radiological Awareness Report (RAR)- e Plant Manager? requests 7 investigation and report on the incident u o Management elevates RAR to Potential ConditioncAdverse to PtA08- ,; Quality Report j +' e Vice. President . Nuclear. requests-independent : Safety; Engineering'
assessment of the potential for overexposure ! r , - ..... ' l ! . .7 =.. . .. . .. . = ... .. ........J l - ,- , . . . .. , - . CSA Lift CONCLUSIONS // e Although a potential for exposure in excess of 10CFR20. limits existed, none occurred o e CSA Lift was-not properly planned y or' executed / e Well-trained Radiological Technicians equipped with proper monitoring l4 equipment prevented overexposure l l ! i i ! , - - _. _ _ - _. _ _ _ - _. - _ - .__-- . _ - . ) ... . - . t i
CSA Lift i i ROOT CAUSE ,
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. e No effective method for assessing / , CSA ' position relative to the refueling ' canal floor
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.- - p'., ! i CSA Lift ! CONTRIBUTING FACTORS
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j e Governing procedures were not ! followed i i e Supporting procedures not consulted I e inadequate pre-evolution briefing ' c e Management participation not !,a adequate i e Failure to take obstructions into. consideration when planning the CSA , ' move back to the reactor vessel . e Radiation Work Permit was
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. ? l CSA Lift CORRECTIVE ACTIONS
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! j Prompt ! e Reviewed other existing Radiation Work Permits ' (RWPs) and cancelled RWPs where potential , [ problen* were identified i e Guidance issued to Toledo Edison station i ' management to ensure proper oversight and , i control of major evolutions > i
. e Assigned upper level management individual to
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participate in. subsequent head lift l
i . l . l l ! n ' .. . . .. .... .. .. . .. - .. .. . . -. . ... .... - - .. _ _ _ _ _. _ _ _ _ _. _ _ _ _ _ _ _ - - -
- i. ... . . CSA Lift CORRECTIVE ACTIONS { cont.) . - Follow-up ) , . / e Provide positive indication of equipment position when moving equipment in the refueling canal ' e Revise procedures , - to require separate Radiation Work Permits when dealing with multiple components with varying
radiological control requirements ~- - to establish maximum value for CSA Lift and to
establish provisions for verifying clearance l between the CSA and refueling canal / floor
obstructions e Re-emphasize and enforce pre-job / ALARA briefing requirements for major evolutions i / e Proceduralize the responsibilty for Toledo Edison L control of contractor activities
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... . . . - . Refueling Canal Drain Down
l l i l e Evolution Summary
e Sequence of Events l- , l e Conclusions i
L e Root Cause .,
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- e e Contributing Factors i
i e Corrective Action , l . , t f, B -..... . . . . .- - .-.-. .-....- . . - .. .. .. ~... . ... . .. ... ... - _ _ - _ -. _ - _ - _ _ _ - - - _ - - - _ _ - . t , .. i . l ' - . ~ ' Refueling Canal Drain Down . I EVOLUTION SUMMARY
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e Operations personnel were draining the Refueling ! l Canal to the 578'6" level (approximately 6" above l l ! the reactor vessel flange) using Decay Heat Pump i 1-1 . < , I e Reactor vessel unintentionally drained to approximately one foot below the reactor vessel . ' ! flange o Control Room Reactor Operator and Containment , <;J Coordinator recognized drain down anomaly
i e Decay Heat Pump 1-1 shutdown and vessel gravity , ' filled to Indexing _ fixture level within seven minutes i ! e Decay Heat Pump 1-2 provided shutdown cooling ! , throughout the evolution ! ) l - . i h , i 1 ... -... - . -. .... -. -. .. -. - -. - - - .. - . -. -... -. -.. -.. - L ,.. . Refueling Canal Drain Down SEQUENCE OF EVENTS ! e initial Conditions - Plant in Mode 6 { e 04/30/90 2200 - Started draining the refueling canal to the , l BWST via DH Pump 1-1. Refueling canai level at ' approximately 23.5 feet 0 05/01/90 ! !
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0113 - RO noticed LI-214 was decreasing and . refueling canal level was not. Containment Coordinator notified CR of the same anomaly 0115 - Drain flow to BWST reduced and DH Pump ! 1-1 shutdown. Approximately one foot of plenum uncovered , i 0118 - Closed DH Pump 1-1. suction from loops (DH 1517) and opened -DH Pump 1-1 suction from j BWST (DH 2733) to gravity fill vessel . 01i!5 - Vessel level equalized with refueling canal l ,) < ' i i I _ _. - - - - - - - - - - - _ _ - - _. _ - _ ____ __ __ _ _ _ _. ~ -- -- . - - - $1 - - . -- - . . ~ lI q , 214 . . I ORIGINAL WATER LEVEL t f g-m - - s_ - - , w ___. -- - , , - REFUELING I ARGE T WALUE F OR < g CANAL FLOOR ORAINDOWN EL.578' -6-162) f ~d INDEXING o ~ FirTURE A vg y p r Et.578'-0* -
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h o PLE!JUM - TO SGl.1 TO SGI-2 L y ,~ '- ~'
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, > - HOT LEG - p-HOT ', c' O ~ U STEAM GENERATOR TOP or rORE I-I DHI2 % \\ , DHI1 \\ _ REACTOR CORE - ooo i L l REACTOR , vtSSEt TO DHISIT DH1518 . i REACTOR HM-VESSEL l - RCP - lI I-2' C BwST . - 1500 to GPM REACTOR VESSEL I f ' ... ...... . . . . -. .. - - ... .. . . . -. . . . - . . . .... . . _.. - - - - - _ _ _ _. - - - - -_ _ _ -_-___-_ _ , . U ... . .
( , , ! Refueling Canal Drain Down , . ! CONCLUSIONS ' , , i i i e Evolution had no safety significance
! l e Operator response as expecte.i . l e No loss of decay heat removal ! , , ih I ' ' i , ! l ! !,d ' > ' I i , l l: - - l-
- . , , i i b i ' . -... - -.... .... .. ..... -. .... . - ~.. ~. - _ _. _ _ _ _... _ -..... _.. -. _ _ _ ~ _ _ _ -, _... -.. - _. _. - _ _ _. _ _ _.. _ _ _... _ _ -.. _ _ _. -. _. - - . . ... . . . Refueling Canal Drain Down ROOT CAUSE ! e Failure to recognize the effect of the presence of the indexing fixture on drain down - i i . I iJ i , !' ' . ' ' , } 'l 18 ) ! ' -.__ _ - ___ _.___ _ _ _ _. _ _ _. _ _. _ _ ____ , j . . . ... i . ., ' Refueling Canal Drain Down
CONTRIBUTING FACTORS j ' !
' / , ., e Indexing fixture served-as cofferdam
e Operators were not cognizant of the status of the indexing fixture i , . ' e Ambiguous activity descr.iption on j schedule for indexing. fixture status.
i o Deficient-pre-evolution briefing . . m e No pre-evolution walkdown , i , . , , b o
i , . . 1 , P ' , I . ..__.________m_a, .- . + - 1-,. -,r m. . ..,,smo,_ -... w.-- e. ...c v.www,%,-, - .- -wv,,--,.,.. , ,-_%-.,w, - . . .. . . Refueling Canal Drain Down CORRECTIVE ACTION . j Prompt e Operations Superintendent lasued memo providing guidance-on responsibility and leadership of the Shift Supervisor: responsible for activities performed on shift provide leadership and be the role model for , ! others l must demand to know what is occurring, how ! W things are going, and who is controlling the evolution
' - has the responsibility-and authority to stop any activity that, in their opinion, needs to be stopped e Stressed the importance of a pre-evolution walkdown to licensed operators > Follow-up e Revise refueling canal drain down procedure to address effects of indexing fixture i l i 1 . _. _. _ _ _ _ _ _ _. _ - _ _ _ __ _ _ _ _._ _ _ _ . _ _ _ _ _ _ _ , . .. , ! . . .
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i I i l , . = , I- , l l l l . , OTHER INCIDENTS - , t , . i - , JUNE 1,1990
I I , I t t l + . 4 > I
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OTHER INCIDENTS ! \\
! I i l e ECCS Injection i e Steam Generator Overfill i ! l e Decay Heat Valve Misalignments l 1) 5/22/90 . ' 2) 5/27/90 eSecondary System Overfill
! l l . e +--e----en,-e= vv-w t w - -w-w-,-ew-.-crw-ww-- -w w- ,w m-w-w ee+----*w-w-~,%,w<c w --.*ww-in-w ,+~e,w-,w+ wwow w.w -ww + w w ww-w wwewwe er-ww---ww e -,e w w we-e-w -w ww w r- +-r www vw-e- = -- e + e-w ww-es + c d-w - - - - _ - _ - _ - _ _ _ _ _ _ _ _ _ _ _ - _ _ _ ". ... - . - _ COLLECTIVE SIGNIFICANCE oIndividually these incidents are of , minimal safety significance oCollectively they demonstrate' management and operational deficiencies . ! ' -. ..... - -. _____ -
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. + - . i MANAGEMENT REACTION t i ! i e Events individually evaluated and l
corrective actions assessed
l i eCommunications reemphasizing ! responsibility i ' i eimplemented Senior Operations l Management coverage earlier than . l planned
eimposed quellfled Stop Work / Testing i ! l eimplemented "Go Slow" philosophy l i ! , , j e i %
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OPERATIONS ADJUSTMENTS ! l . <
l l l Pror... ion.ii.m i i i - ! A ! Uwnership
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