ML20150B682
| ML20150B682 | |
| Person / Time | |
|---|---|
| Site: | 05000083 |
| Issue date: | 06/23/1988 |
| From: | Vernetson W FLORIDA, UNIV. OF, GAINESVILLE, FL |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| Shared Package | |
| ML20150B685 | List: |
| References | |
| NUDOCS 8807120120 | |
| Download: ML20150B682 (2) | |
Text
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O NUCl. EAR ENGINEERIN@ SCIENCES DEPARTMENT Nuclear Reactor Facility University of Florida o
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NUCHAR REACTOR BUUMNG 1988
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' Clutch Current Indicating Lamp Failure
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- Final (14 Day) Report Nuclear Regulatory Commission Suite 2900 101 Marietta Street, N.k.
Atlanta, Georgia 30323 Attention:
J. Nelson Grace Regional Adminis trator, Region II Re:
University of Florida Training Reactor Facility License : R-56, Docke t No. 50-83 Gen tlemen:
Pursuan t to the reporting requirements of paragraph 6.6.2(3)(c) of the UFTR Technical Specifications, a description of a potential abnormal occurrence as defined in the UFTR Technical Specifications, ".hapter 1 is described in this 14-day report to include NRC notification, occurrence scenario, evaluation of consequences, corrective action and current s tatus. The potential promptly re-po-table occurrence involved burnout of the clutch current indicating lamp f or control blade Saf ety-2 at full power.
NRC Notif ication The Executive Committee of the Reactor Saf ety Review Subcommittee (RSRS) re-viewed this occurrence on June 13. 1988 and conuluded that it is a potential abnormal occurrence as defined in UFIR Technical Specifications, Chapter 1.
The Executive Committa also concurred with management res tart approval sub-ject to NRC concurrens. The RSRS then ins tructed NRC notification as per Sec-tion 6.6.2 of the UFTR Yn h Spees. This notification was carried out by both telephone to Mr. Paul Ft erickson and a f ollowing telecopy on June 13, 1988 (see Attachnent I).
Initial Event Scenario On Friday, June 10, 1988 at 1720 hours0.0199 days <br />0.478 hours <br />0.00284 weeks <br />6.5446e-4 months <br /> af ter approximately 5 1/2 hours of sam-ple irradiation at f ull power (supporting neutron activation analysis) in pro-g co o gress, the Control Blade Saf ety-2 clutch indicating lamp (see marked section
$8@
of Attachnent II; Figure 7-1, Overall UFTR Ins trumentation and Scram Logic gg Diagram) burned out, dropping Control Blade Saf ety-2 f rom 56% withdrawn to the cm fully inserted position. The reactor operator at the controls responded
- O promptly by conducting an unscheduled reactor shutdown per SOP-A.4, Reactor y
Shutdown with the reactor secured at 1722 hours0.0199 days <br />0.478 hours <br />0.00285 weeks <br />6.55221e-4 months <br />.
wO Evaluation of Consequences Str Reactor s taf f and adminis tration including Director '.i.G. Vernetson concluded
$$co there was no compromise to reactor saf ety in this event, nor was there any impact on personnel radiation doses. All control and saf ety sys tems respondeu 2.
properly.
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f Nuclear Regulatory Commission June 24, 1988 Page Two i
Based on evaluations of this event, res tart was recommended following replace-h ment and retes t at all clutch indicating lamps including associated required surveillances such as control blade drive and drop tirne checks. Discussion and review of Technical Specification requirements (see Attachment III for applic-able sections of Technical Specifications) indicated that:
1; Congrol Blade Safe:y-2 at the 56% withirawn position-is worth about 132 x 10 A k/k, or N 1.9 dollars of reactivity.
2.
A special report is required for an uncontrolled or unanticipated change in reactivity grcater than one dollar (excepting reactor trips from known causes - this event is a gravity drop of one control blade into the reactor as a result of terminating power to the blade drive magnetic clutches, but.not a Reactor Trip as defined in Technical Specifications ;
see Attachment III).
Corrective Action Immediate corrective action consisted of replacing the bucned out clutch cur-rent indicating bulb to include the necessary control blade drive and drop time checks 3 All were successful so the reactor was restored to operating s tatus on June 15, 1988.
Although there are no radiological or saf ety consequences of this event,.such f ailures are to be avoided. Theref ore, since a clutch indicating lamp f ailure occurred last year (at shutdown conditions), the f requency of preventive clutch current indicating lamp replacement will be. increased f rom annual ver-aus semi-annual preventive maintenance. This action is in agreement with pre-vious management evaluations and discussions with the RSRS Executive Committee on June 13, 1988. This actin is expected to reduce significantly the likeli-hood of recurrence of this f ailure event.
Current Status Since res tart on. June 15, 1988, there has been no recurrence of f ailure of any clutch current indicating lamp.
Sincerely, William G. Vernetson Director of Nuclear Facilities WGV/ps At tachmen ts khkuO (ddCON lob U
' Da te Notiry.
cc:
P.I..
Whaley Reactor Saf ety Review Subcommittee D O' D 'N M8 Document Control Desk 4 (meh.kn Er.nu Abh 22, 1991 besies ins far.f f a.a to:wame ;rw.
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