ML20206C604
| ML20206C604 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 11/08/1988 |
| From: | Colburn T Office of Nuclear Reactor Regulation |
| To: | Virgilio M Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8811160342 | |
| Download: ML20206C604 (2) | |
Text
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Nov e r 8, 1988 0< s t.r' b At' on n
~Ipoetem + e; s NRC & l.ocal PDRs PDIII-3 r/f MVirgilio TColburn PKreutzer iv.EMORANDUM FOR:
Martin J. Virgilio Acting Assistant Director for Rerion !!! and V Division,of Reactor Projec';s III,
!Y, V and Special Proje',ts FROM:
Timothy G. Colburn, Sr. Project Manager Project Directorate III.3 Division of Reactor Pr>jects !!!,
IV, Y and Special P ojects THRU:
John N. Hannon, Director Project Directorate !!I-3 Division of Reactor Projects III, IV, V and Special Projects SUDJECT:
1987 SIGNIFICANT PRECURSOR EVENTS IDENTIFIED BY AE00 As requested by Richard Dudley's note of October 13, 1988, I have reviewed the AEOD evaluation of the February 27, 1987 significant precursor event (two diesel generators inoperable) for the Perry Unit 1 facility to determine:
(1) i whether the event was of high safety significance and the basis for that determination, and (2) whether the licensees' corrective actions were sufficient. Based upon my review, I believe that the event was of high safety l
significance and that a significant contributor to the event was an inexcusable failure by the licensees to correct known equipment deficiencies before they led to accelerated degradation of related equipment and subsequent inoperability of both the Division I and II emergency diesels. The licensees' corrective actions appear to have been thorough and comprehensive.
The licensees had known that two 3-way energized air solenoid valves were f
I leaking and had inittete<1 work orders to correct the problems. However, the licensees erred in their decision that the condition of the solenoid valves did not require imaediate action to repair.
Subsequently, the valves degraded to the extent that during performance of February 27, 1987 Surveillance Instructions both Division I and Division II diesels failed to start and were l
l declared inoperable. The licensees speculated that faulty control air pressure l
regulators r.ay have been a contributing cause. This conson mode failure led to botn emergency on-site power sources being inoperable. The HPCS diesel was unaffected. Both diesels were restored to operable condition within 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />.
f0 8811160342 881108 i
PDR ADOCK 05000440 0
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The licensees have taken significant corrective action in response
.9 this and other control air related diesel generator failures to upgrade and overhaul the diesel generator control air start system to a "like-new" condition and have received manufacturers' certifica'eion verifying that status. They have subsequently demonstrated through testing that, diesel generator reliability has been restored to above the.95 acceptance lev >:1.
They have revised procedures to improve their decision-making processes with regard to assigning work order priorities.
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[,,LT/p/k.dMr<+s-Timothy G. Colburn, Senior Project Manager Project Directorate !!!-3 Division of Reactor Projects - III.
]
IV, V and Special Projects cc: DCrutchfield GHolahan l
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%, previous-colicurrance i
Office:
LyfQJJI-3, PM/PDIII-3 PD/F I I-3 i
Surnate:
PKreutzer N TColburn/mrh, JHannon
///}/88 i
Date:
u / 7 /88
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