ML20136F664
| ML20136F664 | |
| Person / Time | |
|---|---|
| Site: | Limerick, 05000000 |
| Issue date: | 01/29/1985 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20136E841 | List: |
| References | |
| FOIA-85-668 NUDOCS 8502050537 | |
| Download: ML20136F664 (4) | |
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i UNITED STATES NUCLEAR REGULATORY COMMISSION Er WASH 1880 TON, D. C. 20558
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JAN 291985 ll.
MEMORANDUM FOR:
.Darrell G. Eisenhut, Director Division of Licensing FROM:
Dennis M. Crutchfield, Assistant Director for Safety Assessment Division of Licensing I
SUBJECT:
LIMERICK-1 OPERATING EXPERIENCE j
1 This memorandum documents the Operating Reactors Assessment Branch's review of operating experience to date at Limerick-1 during the low power license period (October 26, 1984 to January 17,1985).
The review included a survey of reoorted events at Limerick-1 during the 2.75 month period between, late October and mid-January (i.e., period of the low power license) and a comparison of the reports with reports from othe.r recently licensed BWRs and PWRs.
The basic sources of the reports were the files of prompt (telephone) notifications filed per 10 CFR 50.72 and License Event Reports (LERs).
Operatirig peactors Events Briefing sumaries were also examined to identify 4
the more significant events.
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Surve_v of Experience The low power license period considered in the survey has extended from October 26, 1984 to January 17, 1985.
In this period, the plant operated in modes 2, 3, 4, and 5 for the purpose of performing startup testing.
Numerical results of the event survey are compared in Table 1.
In the 2.75 month license period, Limerick-1 reported 58 non-security events.10CFR 50.72 reports came in at a rate of about 18 reports / month.
Licensee Event. Reports (LER) have been made at a rate of 17 reports / month. As shown in Table 1 the Limerick rate of 50.72 reports is significantly higher than those exhibited by other recently licensed plants in their low power license periods. Table 2 shows a breakdown of the events reported at Limerick-1 which indicates that the vast majority of events have been inadvertent actuations of Emergency SafetyFeatures(ESF)equipmentduringinstallation,testingandmaintenance of equipment.
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Review of operating reactor event briefing minutes indicates that one event was reported for Limerick-1 at bi-weekly operating reactor event briefings
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during the past 2.75 months.
In this event operators discovered that los:
of e-20VDC power supply to source range and intermediate range neutron i
monitoring instruments would not result in a reactor t'ip as expected. The licensee, witN the assistance of General Electric, determined that for the SRM and IRM.in question the -20VDC power supply keeps :<he alam annuciator relays enercized but a +20VDC supply holds in the prot.sr.tive trip relays.
Therefore, loss o,f the -20VDC source without a simultaneous loss of the +20 VDC source may not cause protective trips, but only the alam. As a correct-ive action the licensee has installed a design change which ensures that both the -20VDC and +20VDC outputs are monitored and that the loss of either would result in actuation of the SRM/IRM INOP protective trips.
Conclusion Operating experience at Limerick-1 has been surveyed for the first 2.75 1
months of the start-up test program (low power license periodT; Review of event reports for this period indicates that the number of inadvertent ESF actuations is significantly higher than expected. We will continue to review i
the licensees operating experience and will be working with Region I and with the licensee in order to identify root causes of these problems.and corrective actions as apnropriate.
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Dennis M. Crutchfield, Assistant Director for Safety Assessment Division of Licensing j
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TARLE 1 RATE OF REPORTED EVENTS AT TEN SELECTED PLANTS DilRING LOW POWER LICENSE PERIOD Period of Low Rate of Reported Events Power Operation Studied (Avg.No. Reports / Month)
Facility (Months) 50.72 LER PWR Diablo Canyon 5
4 4
McGuire Unit ?
3 1-2 1-2 Surmer Unit 1 3
1 14 Callaway Unit 1 3
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Catawba Unit 1 6
5 5
g Gran'd Gulf 21 10 18*
LaSalle Unit 1 4
1 19*
Susquehanna Unit 1 4
3 17 Susquehanna Unit 2 3
2 3
Limerick 1 2.75 18 17
- Includes data from before 1/1/84, 50.73 LER Rule 9
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TABLE 2 BREAKDOWN OF REPORTED EVENTS AT LIMERICX-1 General Category No. of Reported Events
- Technical Specification Violation 8
Deoradation of Safety Eouipment 3
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RPS Actuations Actual. Challenges 0
Inadvertent actuations 2
due to personnel error Inadvertent actuations 3
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t ESF Actuations Actua[ challenges 0
']nadvertent Actuations due to personnel error 22 I
Inadvertent Actuatinns
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due to eouipment problems 20 TOTAL 3
- This is total number of unique events reports made through either ENS (50.72) or LER.
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