ML20045H253
| ML20045H253 | |
| Person / Time | |
|---|---|
| Site: | University of Virginia |
| Issue date: | 07/09/1993 |
| From: | Mulder R VIRGINIA, UNIV. OF, CHARLOTTESVILLE, VA |
| To: | Vernetson W FLORIDA, UNIV. OF, GAINESVILLE, FL |
| References | |
| NUDOCS 9307200018 | |
| Download: ML20045H253 (19) | |
Text
Y' SCHOOL OF ENGINEERING @
July 9,1993
& APPLIED SCIENCE Dr. William G. Vernetson, Chairman NUCLEAR REACTOR FACILITY ocpanment or Mechanical.
National Organization of Test, Research and Training Reactors Aerospace & Nmicar linginening c/o University of Florida Training Reactor University of Florida g ni,c,s;,,og y;,p;ni, Charlouessille, VA 22903-2442 Gainesville Florida soa m 2-5440 i:AX: No4M2-5473 32611
Dear Dr. Vernetson:
Please find enclosed our response to the findings and recommendations presented in the official TRTR peer review report on the UVAR Console Event of April 28,1993. Each finding and recommendation is addressed separately. For brevity, a summary of the event is not repeated.
The account of the event given in the TRTR report is accurate and complete.
We would like to thank you personally for arranging and participating in the TRTR peer review on such short notice. Our thanks also go out to Mr. Tawfik Raby and to Mr. Wade Richards who collaborated in this endeavor. The TRTR evaluation of the overall administration and operation of the University of Virginia Reactor Facility provided us with useful recommendations which have been considered and generally implemented as part of our comprehar ve corrective actions.
The UVAR Console Event was a serious occurrence which should not have happened. We believe that a similar event will never occur at our fa.dity because the corrective actions implemented have been broadly focused. Please fcci free to use in the TRTR newsletter any of the information which we have provided to TRTR. An open analysis and discussion of this event should serve to prevent similar occurrences at other TRTR facilities.
Again, many thanF for your help.
Sinectif,n '. -
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he'h,g M ', // ~ /
Robert U. Mulder, Director U.Va. Reactor Facility ec: J.ll. Sniczek, NRC J.G. Parlow, NRC ILK. Grimes, NRC S.ll Weiss, NRC S.D. Ebneter, NRC T.IL Raby, NIST l
W. Richards, DoD '
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TRTR Findings i
- 1. The spurious UVAR trip on the morning of April 28,1993 had seemed to be a soft trip indicating all rods had not dropped simultaneously. As a result it was felt the source of the spurious trips might be isolated to one side or the other of the Scram Logic Drawer.
Licensee: The "symious" scrams occurred without an identifying cause registedng on the trip annunciator. These trip signals were intennitterv in the sense that the reactor could be operatedfor weeks without one occuning. When one would occur, for a time the likelihood of repeated trip signals would be great. These scrams were an annoyance, given the difficulty foreseen in tracking down an i.itennittent source. Since November of 1992, there were 20 annunciated scrams and 15 spudous scrams. No safety imponance was attributed to these trips since research reactor scrams do not appreciably challenge the reactor protection ,
systein.
- 2. The two solid st; o relays (SSR) were switched in the Scram Logic Drawer as a part of troubleshooting to discover the source of the earlier spurious trip. When the intermittent bus spurious trip indication remained, the SSRs were eliminated from consideration as :
the trip source and left in the new position. Though this is good troubleshoot'ing methodology, this switching should itself have been '
tracked as a temporary modification for which some sort of test or checks would be required. i Licensee: It is agreed that the switching of what were believed identical ,
console modules should have been fonnally tracked as trouble-shooting or maintenance with testing for operability required before retum to sen' ice. ihe SRO who perfonned the module crchange, and later the Supervisor who approved reactor restart, did not recognize this at the time. Il'hile no definition for maintenance and trouble-shooting existed in the UVAR SOPS, good-sense should have dictated that the Daily Checklist be repeated to test the scram availability, because the system invoh'ed was a reactor protection (safety) system and the possibility that
" identical" components might not operate in the same way can't be nded ;
out.
i l
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~ - - -. - -- . .- .
(Response to the TRTR Peer Review Report, page 2, cont.) !
- 3. The two mixer-driven modules were also switched as part of the troubleshooting effort to isolate the source of the intermittent ,
spurious trip signals. When the intermittent trip signal failed to '
return after a period of time, the switched MD modules were left in place and the reactor was restarted by the cognizant SRO with the knowledge of the reactor supervisor. Since the two MDs were not identical due to previous modifications, this action constituted a modification of the safety system. This unintentional inadvertent i modification of the UVAR safety system disabled a number of trips for 5.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> of operation due to switching non-identical mixer-drawer modules on April 28,1993 and was the direct cause of the -
reportable occurrence.
Licensee: The streak of spurious trip signals on Apdf 28 lasted long t enough for the SRO who perfonned the module exchanges to conclude, with the reactor shutdown and the console on, that the SSR were not the cause of the spurious scmms. Following the archange of the AfDs the spurious trip signals ceased and no conchision about the AfDs could be :
reached. This provided the incentive to leave the AfDs in th: :rchanged position, and let the trouble shooting continue concurrently wi'h reactor operation. Had the modules been identical and checked for operability in the erchanged position, this course of action would have been reasonable because reactor trips at research reactors do not appreciably challenge the safety system. ;
7hc AfDs had been internally modyled in the early 1970s by personnel no longcr employed at the Facility. These modifications were not recorded in the official console . schematics. The modifications involved tying-off together the unused inputs inside the AfD modules.
Unfortunately, the unused inputs conespondea to different numbers on both sides of the scram system. The asymmetry between the two lines in ;
the scram logic drawer had its origins in the first console design which ;
used vacuum tube technology. In the 1970s the console was upgraded ,
with a mininuun of change. Perhaps, the tie-off were not recorded '
because they did not affect the scram logic with the AfD in their original positions. lie-off of unused inputs is conunonly perfonned on modern low voltage and cunent chip-based circuits, but was not necessary for the p
AfDs which contain simple transistors, resistors and diodes.
l (Response to the TRTR Peer Review Report, page 3, cont.)
The effect of the tie-offs with the MDs in exchanged positions was to introduce jmnpers into the scram logic circuit and tie together a ntunber ofimportant scrams. This was the physical cause for the console event. }
Given that one of the scrams jumpered was the key-switch scram, only l with the key out of the console could the scrams' have been able to operate in unison. Hence, a number ofimportant scrams were unavailable, singly or collectively.
- 4. Because the two mixer-driver modules were considered to'be identical l '
per Figure 3.15 (Scron Logic Drawer) of the UVAR Safety Analysis Report, no tests or checks were performed following the switching of :
the MDs. ~
Licensee: Only the SAR was consulted. Ilie Technical Specifications and the console schematics should also have been consulted by the staff The Technical Specifications required proceduralfonnality for console maintenance activities, and testing prior to return to service. IVhile the 1 internal MD module jumpers wordd not have been listed on the official console schematics, the operator would have been alerted about the .
asynunetty of the scram system, 77 tis might have triggered the operator's memory about a proposa! he had submitted to the Reactor Safety Conunittee a decade earlier suggesting that the scram logic drawer input :
lines be made synunetric. (77 e proposal was not approved.)
- 5. There is only one daily checklist performed per day. Regardless of .
other occurrences, there is no specific requirement to perform )
another complete checklist or any part of the checklist.
Licensee: The UVAR SOPS have been developed and refined over a 33 year period. During this time, no event similar to this one had occurred.
Given the benefit of erperience, a specific requirement to test the safety system opembility following all reactor trips now exists in the SOPS. Itis noted that if good-judgement had been erercised the Daily Checklist wordd have been repeated and the console event avened.
The new SOP requirement requires a check of the safety systems be perfonned prior to a restart following all trips.
1 j
(Response to the TRTR Peer Review Report, page 4, cont.)
- 6. Licensed. staff members do not all understand the same re'quirements for approval to start up the reactor'or to' restart following a trip. It is !
also not clear who has authority to restart and who is rc:ponsible to approve restarts dependent on whether the cause is known or not. >
Licensee: The staffis composed ofpersonnelfrom various bac@ rounds and with different assigned responsibilities and duties. However, management should capect a conunon understanding ofline -
management authority and responsibility to exist. lliis deficiency has _
been addressed by specific retraining on personnel authority and l responsibilities, and by a revision of SOP 3 on Personnel Responsibilities. {
In the revised SOP 3 the Reactor Supervisor is identified as the focal i point for all reactor operations. SOP 3 was submitted to the Reactor i Safety Conunittee for review and approval. 77:e committee has requested ,
that the SOP be made re-wntten, to make it shoner and more general.
i Restart following reactor trips now requires fonnal apjnoval and '
signatures on a Safety Systems Checklist fann from the Cognizant Senior ,
Reactor Opemtor and the Reactor Supervisor. The Reactor Director will ;
be notified when the cause for a scram can't be detennined.
- 7. There is no clear delineation of who has the authority and responsibility to approve apparently minor and in some cases significant changes at the facility. Depending on the licensed individual interviewed, different levels of authority are understood to be provided to them without any clear documentation of this authority. Similarly there is no clear understanding as to who may authorize and approve significant items of maintenance, repair and :
other activities and what checks or tests are required following completion of the task.
Licensee: The stag had been erpected to recognize the safety ,
significance of their actions, as well as understand the different levels of authority'. lluts, pdor to initiating significant actions, it was expected ;
that major items of safety sigmficance would be brought to the attention of the Reactor Supervisor and the Reactor Director. Generally, this has been the case with the exception of the recent event. Proposed major changes
'(Response to the TRTR Peer Review Report, page 5, cont.) 1 were first described in writing,10CFR50.59 analysis performed, the Reactor Director involved and the Reactor Safety Conunittee considted ,
for approval. Ilowever, in the case of the MD exchange the SRO and the Reactor Supervisor wrongly judged that no change to the facility was possible! Ilence, it is conchided that the " threshold" for what constituted a minor and major change was insufficiently clear and that er, ors in judgement occurred.
Presently, clearer delineation and procedural guidance addressing this finding exists. Nwnerous procedures were revised and improved. The. '
revised SOP 3 on Personnel Responsibilities has been descdbed already - .
as a response to TRTR finding #6.
9
- 8. There is no clearly established focal point for control of operations-related activities at the UVAR facility. Careful evaluation indicates the restart following switching the MDs was agreed to more than approved by the reactor supervisor with no documentation of the restart approval by the reactor supervisor. -
Licensee: There are six licensed individuals on staff who opemte the reactor. Because of seniority, two of these persons are in state-of-Vhginia " Reactor Supervisor" slots. l1te senior-most of these had been referred to as tise " Reactor Administrator" and the other as the " Services Supervisor." On occasion, the Services Supervisor would be the acting Administmtor when the Administrator was away on leave.
IVhile having two supervisor positions is confusing to outsiders and potentially confusing to staff members, it is noted that in this event the SRO aptnoached the right individual for approval to restart following MD exchange. ,
it is agreed that the reactor supervisor did not act as the " focal point for -
control of opemtions-related activities." The explanation given belowfor tlis is not meant as an etcuse. It is offered because it could be true at other university reactors. IVhen the staff size is small, the operator tum-over rate low, and one individual is the acknowledged 1
1
-I
4 L' (Response to the TRTR Peer Review Report, page 6, cont.)
expert in an area of reactor operations, a supervisor may fail to project j the necessmy authority, becoming acquiescent and complacent. This was one of the root causes for the UVAR Console Event. 11ad the supervisor asked the SRO some key questions, good sense woidd have prevailed and 1 testing would have been done. ;
In recognition of this root cause, the line organization for reactor operations at U.VA. Reactor Facility has been described in a policy statement given to the staff an updatable board listing the names of the t Supervisor, the Cognizant SRO, and the operator at the console was .
affred to the entrance of the reactor room; procedures were revised to >
make the Reactor Supervisor the focalpoint for operations (he muu be regularly updated about the status of reactor operations); and the in-house title of Reactor Administrator was changed to Reactor Stipervisor, o and that of Services Supervisor changed to Services Manager.
L
- 9. Shift turnovers after the restart made no special mention of the switched MDs. Operators, as part of good practice, did make .;
themselves generally aware of the switching. Nevertheless, the shift l turnovers themselves made no mention of the troubleshooting mode- !
of operation. This lack of communication was considered acceptable ,
because any further spurious trips would come through one or the other of the two MD modules, either proving one of them as the cause of the trip or eliminating them from further consideration. It- .,
was tacitly assumed that the cognizant SRO would be the person .
called and informed of such a trip so the requisite information would !
be available to that individual upon notification that there had been a trip. Nevertheless, there was no specific direction given to the. 1 operator to notify the individual should there be another spurious trip.
Licensee: Prior to this event, operator turnover would not have been considered a problem. Good turnover practice had been reconunended during operator requalification meetings. '
To explain the tumovers on the after,toon of May 28, the SRO who made the exchange and perfonned the reactor restart tumed his shift over b
l (Response to the TRTR Peer Review Report, page 7, cont.)
to the then Services Supervisor. This junior supervisor had not been invoh>cd in the approval process of the module exchange, but had been a witness to part of the discussions about the change between the SRO and the reactor supervisor. Because of this, the SRO did not feel compelled to provide full details on his tumover. 17:e third and last operator at the ,
console that aftemoon had recently been granted his NRC license. The ;
then Services Supervisor made it a point to serve as a second operator in -
the control room with the new operator at file console.
The first SRO believed his entries into the Reactor Logbook would be '
sufficient to alert the other operators. However, it is acknowledged that this SRO should have left an advisory note at the console explaining the troubleshooting in progress and requesting that he be called in the event !
of another spurious scram.
1
- 10. The external organization of the reactor facility is not well suited to the UVAR. There is no clearly defined line management responsibility for safeguarding facility personnel and the public. This responsibility is being met but in a non-optimal manner as the President of the University acts as the licensee which is,not necessary since University and NRC requirements can be separated. :
Licensee: The TRTR peer review group defined the " external organization" to be the positions in management above that of the '
Reactor Director. It is true that university officials at a level above that of Chair of the Department of Mechanical, Aerospace and Nuclear Engineering have only a cursory understanding of reactor operations. i This finding already was addressed prior to the UVAR Console Event. !
By request of U.Va. 's President, a Technical Specifications amendment :
was submitted to the NRC many months ago, in which the Chair of the Radiation Safety Conuninee would be made the coordinator for all NRC ;
licenses, including the reactor licenses. The NRC will consider this '
amendment following the conversion of the UVAR to LEUfuel.
P J
(Response to the TRTR Peer Review Report, page 8, cont.) ;
i
- 11. The actions of the facility following discovery of the problem after -l shutdown have been conunendable. Actions taken to include the extended shutdown with the reactor tagged out, the decisive actions taken to identify and isolate the immediate cause and return the system to normal, the actions taken to generate new checklists, new procedures and communications with the staff are all' duly-acknowledged as exemplary. The decision to check as well as clearly and permanently label all components intended for use in the UVAR console is another exemplary response to the occurrence. The staffis clearly committed to improving facility operations and earning permission to restart. -
Licensee: All concerned at U.VA. Reactor Facility are dismayed that this event happened, because of weaknesses in the procedures and management conuols. 17is event should not have occurred, nor should a similar event ever happen again at Virginia, or elsewhere. Reactor management is committed to betterperfonnance in thefuture, mindful of the negative impact such events have on the University's prestige, and also on other members of the TRTR community. For these reasons, many corrective actions were taken to broadly address the problem.
- 12. The quality of reactor personnel appears high and impressive.
Licensee: 11:e reactor staff at the U. of Virginia reactor is skilled in reactor operations and associated specialties.
The SRO who perfonned the MD erchange is very capable in electronics and came to U.VA. with a solid nuclear-navy background. 11 was out of character for him not to have paid more a!!ention to testing the system.
7'his event points out that even the best reactor operators are at risk of making serious mistakes. Such personnel must be aware of the potential they have for making mistakes. Therefore, they should welcome (and on occasion demand) management checks and control.
Despite the small numbers of operators at university operated research reactors, the maintenance ofpersonnel with electronic expenise is one of our permaaent goals.
i
. t (Response to the TRTR Peer Review Report, page 9, cont.)
TRTR Recommendations '
1.
Though the failure to perform adequate tests or checks following switching apparently identical components in the UVAR safety
, system is the inunediate cause of this event, the root cause of this i
event is evaluated to be an institutional problem. We find there is no clearly defined line management responsibility for operations-related activities. A focal point to clear and control all significant operations related actions at the facility through a documented person in charge as the reactor supervisor is essential. Prior apthorization and :
approval of this individual should be required'for all significant activities associated with the reactor. The reactor facility organization should be structured to clearly define these lines of responsibility and authority.
Licensee: In the response to TRTR findings 7 and 8, this reconunendation has been fully implemented as it relates to the Reactor Facility management. The outside management issue appears to have been addressed in a requested amendment to TS made pdor to the console event.
- 2. It should be made clear via procedures and periodic training that any time there is any kind of work on the UVAR safety system, appropriate checks must be performed commensurate with the work that has been accomplished. There must be a clear demarcation as to who makes changes as well as who authorizes them. Specifically it is recommended that at three tier system be implemented to control
- UVAR facility changes in the following categories:
- a. Minor and temporary, non-safety system related changes may be approved by the SRO or the Reactor Supervisor.
- b. Minor and tempormy changes affecting the safety system may [
be approved by the Reactor Administrator or the Director.
l l
J (Response to the TRTR Peer Review Report, page 10, cont.)
- e. Other than minor changes may be reviewed and approved by the Reactor Safety Committee with final approval by the-Director with special considerations given to changes whenever the reactor safety system is involved.
The same system of controls and approvals should be applied not only for design changes but also for changes in SOPS, tests and experiments. A determination that all such changes do not involve an unreviewed safety question should be made and documented. The -
degree of documentation should be dependent upon the level of the .
change.
Licensee: This recommendation has been adopted in its essence. To a significant degree, the thmst of the recommendation was being met prior to the console event for activities exchiding non-routine maintenance and troubleshooting.
- 3. The UVAR also needs an adequate restart checklist _as well as controls as to who can approve restart. Here, the review team recommends that restarts following trips be categorized at two levels.
- a. Restart following a trip from a known and corrected cause for which satisfactory checks have been completed should require SRO approval.
- b. Restart following a trip from an unknown cause where conditions appear normal based on significant checks should require reactor supervisor approval as the focal point for all operations-related activities. Any time checks indicate uncorrected problems, then the restart should not be approved; the level of responsible authority must be defined for such cases.
As a further note the review team feels the proposed safety systems checklist (a subset of the full daily checklist) may be more extensive 4
e, -
- , 4 )
(Response to the TRTR Peer Review Report, page 11, cont.) '
than necessary for many trips, especially those from known.causes
- where the cause has been corrected. We reconunend the facility consider a further reduced subset of checks though this decision on adequate checks must finally fall to UVAR management and staff ,
based on their detailed knowledge of the facility.
Licensee: The UVAR reactor staff recognized inunediately following the event the desirability to require by procedure that checks of the safety systems be perfonned pdor to reactor restans following trips. Restans now require both the approval of the Cognizant Senior Operator and the Reactor Supervisor. 7he Reactor Director will be notified of trips from unknown causes. Currently, the safety systems checklist covers all safety- ;
related systems. IVe will study how well this checklist serves its purpose, and ifil proves to be too onerous sve Inay consider trinuning it dolyn to a mininuun number of adequate checks, with prior Reactor Safety Conunittee approval.
- 4. '
We reconunend that certain procedures related to control of maintenance, repair and modifications should be developed and/or improved and better implemented. This process is currently-in ,
progress with the new SOPS appearing to address the issues of controlling maintenance and modifications in a substantive manner.
We recommend that these be implemented as soon as practicable.
Licensee: 1his reconunendation was implemented as a necessary can'ective action pdor to UVAR restart permission being obtained from our Reactor Safety Conuninee.
- 5. We recommend that a certain area be designated for storage of components intended for use in the UVAR console. These should be clearly labelled for storage of components intended for use in the -
UVAR console. These should be clearly labelled in storage your :
decision to mark them is good. Some consideration should also be
- given to scaling them in protective bags since many replacement components may Se stored for years prior to usage. The key here is
4 i
(Response to the TRTR Peer Review Report, page 12, cont.)_
l to reduce the possibility of using a defective or unapproved component though it is recognized that proper checks and tests will provide final protection against such defects.
Licensee: This reconunendation wih* be implemented. We agree that final protection against defects and non-confonnities is provided only by '
proper checks and tests.
6.
As discussed during the evaluation, we strongly recommend that two t people be present in the facility for daily checkouts and for recovery / restart following trips with one in the control room observing '
whenever possible. -
Licensee: The Daily and the Safety Systems checklists will ahvays be perfonned with two people in the Reactor Facility, with one present in :
the control room.
7.
We recommend that the transfer of console duties and shift responsibilities be more formalized. Specifically we recommend '
documenting in the log when the turnover occurs and that the '
operator assuming shift responsibility has been briefed on the status of the facility. Such documentation of shift turnovers will serve to alert those coming on shift of facility activities or conditions that may merit special attention. Though interviews with those on duty during the five plus hours when some of the scrams were inoperable do not indicate any special concerns on their part, many occurrences can be prevented or better analyzed if the operator-on-duty has been properly cautioned on what may be ofinterest based on the activities <
in progress.
Licensee: The staff has been retrained on how to properly perfonn shift turnovers and docmnent this in the reactor logbook. It is agreed that cautions and precautions on activities in progress should be discussed at shift tumovers.
i
, - , - --+,w -.a.w,
y (Response to the TRTR Peer Review Report, page 13, cont.)
- 8. If it is feasible and practical, we recommend that the UVAR evaluate the possibility of having two (2) independent strings in the safety ..'
system to actuate all scrams. Though not considered necessary, making such a modification would provide additional redundancy to preclude a failure to scram from failure of one mixer-driver module, especially on the more important scrams (two overpower, low flow and loss of primary coolant pump). We emphasize that care should be taken to assure that failure of one mixer-driver module cannot cause failure of the other; that is that there is no interconnection allowing feedback to cause a evaluation and possibility NRC approval. We emphasize that we do not consider the current design deficient so there is no need for such a change to be implemented or i even fully evaluated prior to restart; however, if implemented it could provide important added redundancy to the safety system.
Licensee: We agree that the present console design is not deficient. We also agree that additional redundancy on important scrams would have been useful. This reconunendation will require considerable study, and due to schedule pressure and small staff this consideration will be deferred until after the deconunissioning of the CA VALIER and the conversion of the UVAR to LEUfuel are completed.
- 9. It is recommended that the external organization of the facility be restructured along the lines of ANSI /ANS 15.1 (The Development of Technical Specifications For Research Reactors) to provide clearly defined line management exclusively for the administration of the !
reactor license. The overall organization should be streamlined so l there is clear line management responsibility for safeguarding facility !
personnel and the public and for discharging their obligations under q the NRC license. The level of a department head or dean is -;
acceptable to meet license requirements; there is no need to involve the President of the University of Virginia. This organization and associated safety committees should be separated from _other .
university organizations, functions or requirements. Whatever j internal requirements are put on the facility by University I administrators can be implemented and assured independent of the :
NRC license. l j
(Response to the TRTR Peer Review Report, page 14, cont.)
Licensee: The thnist of this reconunendation is being addressed and '
eventually a position below that of the University President will be -
responsible for the reactor license, upon approval by the NRC of a license amendment. The exact nature of the " external organization" is a matter ofinternal discussion within the University and with the NRC, and can't be decided by the Reactor Director. Copies of the TRTR report have been circidated to higher management.
10.
Along these lines it is recommended that the Reactor Safety Committee should be set up exclusively for reactor and license reviews. This committee should review things and perform audits in accordance with your Technical Specifications and the ANSI /ANS 15.1 Standard. This conunittee does not need to be burdened with-minor changes which can be addressed by the facility director nor does it need to be part of a larger university committee.
Licensee: The future relationship of the Reactor Safety Conunittee to the Radiation Safety Conunittee was proposed to the NRC in a TS amendment sent in many months ago. Pdor to this, the proposed relationship was a subject of considerable intemal debate. The proposal has the blessing of the President of U.Va. who wishes responsibility for the NRC licenses to be managed by a university official oflower rank, as suggested by TRTR.
The Reactor Safety Conunittee perfonns more than reactor and license reviews, it also reviews and approves procedures and expedments, and major changes thereto. Ilowever, " methods" which implement procedures .
in greater detail are addressed by the Reactor Director. The small reactor staff si:c makes greater oversight of the Reactor Safety Conunittee necessary, to provide necessary professional experience. NRC inspectors have indicated repeatedly they are pleased with the degree ofinvolvement and oversight provided by our Reactor Sajety Conunittee.
1 I
_ (Response.to the TRTR Peer Review Report, page 15, cont.)
- 11. Troubleshooting to determine problem-related causes and corrective action and initiative to improve performance should continue to be encouraged. However, these activities should be carried out in a progranuned, well thought out, well reviewed and structured manner.
We are concerned that the occurrence and subsequent critical reviews may inhibit personnel from taking prudent action when such action is ,
warranted. Such inhibition should not be allowed to occur.
Licensee: Problem analysis and correction will continue and is encomaged by reactor management. The revised procedures callfor progranuned, thought out and reviewed approach to reactor maintenance.
Claims by some staff members inunediately following this event as to inhibitions are understandable in light of the shock felt by all that the event originated from the actions of the most highly regarded senior ;
reactor operator. Ilowever, with counseling and retraining self-confidence has retumed to all members of the Reactor Staff Prudent action will be taken when wannnted. We all conunitted to improved ;
perfonnance.
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(Responso to the TRTR Report, page 16, cont.) -
U.VA.'s CORRECTIVE ACTIONS, SHORT TERM UPON DISCOVERY OF NON-COMPLIANCE WITH LICENSE, REACTOR WAS SHUTDOWN l FOR EXTENDED PERIOD.
ORIGIN & CONSEQUENCES OF EVENT INVESTIGATED. LOSS OF SCRAM FUNCTION WAS UNPRECEDENTED.
TIMELY NOTIFICATION OF UNIVERSITY, COMMUNITY AND NRC.
THREE WRITTEN REPORTS SENT TO NRC.
ReSC BRIEFED ON EVENT W/I 48 HOURS. TliREE FOLLOW UP MEETINGS IIELD.
NEW MEMBER WITH ELECTRONICS EXPERTISE APPOINTED TO ReSC BY U.VA. 'S PRESIDENT.
TRTR CONTACTED AND ASKED TO PERFORM PEER REVIEW.
NUMEROUS STAFF MEETINGS HELD TO ANALYZE EVENT, DETERMINE ROOT CAUSES AND PROPOSE CORRECTIVE ACTIONS.
CONSOLE ELECTRONICS AND SCHEMATICS STUDIED AND COMPARED. OFFICIAL SCllEMATIC UPDATED TO CORRECT A FEW MINOR DISCREPANCIES. SEARCH FOR SIMILAR " TRAPS" MADE.
CONSOLE ELECTRONICS CHECKED & FOUND UNDAMAGED.
MODULE CALIBRATIONS AND BENCH TESTS PERFORMED.
SOURCE OF. SPURIOUS SCRAM SOUGHT AND BELIEVED FOUND.
REACTOR CONSOLE MODULE LABELLING IMPROVED. CAUTION PLACED ON SCRAM DRAWER ABOUT NO MODULE INTERCilANGE.
M/D MODULES RETURNED TO OFF-THE-SHELF STATE FOLLOWING ANALYSIS, REVIEW AND RcSC APPROVAL.
IMPROVED SOPS SUBMITTED TO ReSC AND APPROVED. REACTOR STAFF i
MEETINGS IIELD TO TRAIN STAFF ON REVISED' PROCEDURES. I DUTY-BOARD LISTING NAMES OF REACTOR SUPERVISOR, COGNIZANT SRO AND OPERATOR AT CONSOLE POSTED AT' ENTRANCE To itVAR REACTOR ROOM.
IMPORTANCE OF FOLLOWING PROCEDURES RE-EMPM SIZED TO REACTOR STAFF BY REACTOR DIRECTOR.
REACTOR MAINTAINED SilUTDOWN UNTIL ALL NEEDED AND SUFFICIENT SHORT TERM CORRECTIVE ACTIONS COMPLETED, ReSC RESTART APPROVAL OBTAINED AND DISCUSSIONS WITH NRC FINALIZED.
- .3 1
l
.(Response to the TRTR Report, page 17, cont.)
U.VA.'s CORRECTIVE ACTIONS, LONG TERM COMMITMENT MADE TO NRC TO SliUTDOWN UVAR FOR EXAMINATION AND MAINTENANCE IF 2 SPURIOUS SCRAMS OF UNDETERMINABLE CAUSE OCCUR W/I A 30 DAY PERIOD, DURING FIRST 90 DAYS FOLLOWING RESTART.
TRTR'S PEER REVIEW RECOMMENDATIONS TO BE-CONSIDERED BY JULY .10.
COPY OF FORMAL RESPONSE TO TRTR TO BE SENT TO NRC.
SOP 3, DEVOTED TO PERSONNEL RESPONSIBILITIES, TO BE EXPANDED TO CONTAIN MORE DETAIL AND LEAVE NO DOUBT ABOUT CilAIN OF COMMAND AND AUTHORITY, MODIFICATION OF 2 OTilER MODULES IIAVIllG JUMPERED UNUSED INPUTS TO BE '
CONSIDERED. !
IMPROVEMENTS TO CONSOLE TO BE STUDIED: INCREASE REDUNDANCY TO PERMIT SOME ELECTRONIC FAILURES WiiILE MAINTAINING MINIMUM # OF TS-REQUIRED CilANNELS OPERABLE.
DEFINITIONS FOR MAINTENANCE AND TROUBLE SilOOTING ADOPTED. GUIDANCE AND TRACKING FORM DEVELOPED.
SAFETY SYSTEMS Cl!ECKLIST, AN ABBREVIATED DAILY CIIECKLIST, WILL TEST SCRAM AVAILABILITY FOLLOWING UNPLANNED SCRAMS PRIOR TO REACTOR RESTART.
BOTil REACTOR SUPERVISOR AND COGNIZANT SENIOR REACTOR OPERATOR TO PROVIDE RESTART AUTilORIZATION AFTER SAFETY SYSTEMS CllECKLIST IS SUCCESSFULLY COMPLETED.
CONDITIONS REQUIRING MANUAL TRIP EMPilASIZED IN SOP 2. MANUAL TRIP RECOMMENDED IF UNSAFE OPERATION IS SO MUCll AS SUSPECTED.
PROCEDURE FOR llANDLING TS VIOLATIONS INTRODUCED.
REACTOR SUPERVISOR MADE " FOCAL POINT" FOR REACTOR OPERATIONS.
IMPROVEMENT OF MANAGEMENT CONTROL.
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9 N (Response to the TRTR Report, page 18, cont.)
DEFINITIONS FOR UVAR BOPS TROUBLESHOOTING IDENTIFYING EQUIPMENT IS THE SYSTEMATIC PROCESS FOR PROBLEMS AND THEIR-CAUSES. .!
MAINTENANCE IS THE AGGREGATE OF THOSE -'
FUNCTIONS REQUIRED TO PRESERVE, RESTORE, OR IMPROVE OPERABILITY OF FACILITY SYSTEMS. IT INCLUDES l
SCllEDULED SURVEILLANCES, ,
SHOOTING, REPAIR, AND TROUBLE EXCLUDES MODIFICATIONS. IT Tile EXCl!ANGE OR REPLACEMENT OF ,
CONSUMABLES (E.G. CHART PAPER, LAMPS, RECORDER PENS, '
BATTERIES).
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