ML19276H076
| ML19276H076 | |
| Person / Time | |
|---|---|
| Issue date: | 09/05/1979 |
| From: | Lainas G Office of Nuclear Reactor Regulation |
| To: | Zech G Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7910020720 | |
| Download: ML19276H076 (35) | |
Text
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z, X ii, p* **c%jo, UNITED STATES
,f" y )pe() i NUCLEAR REGULATORY COMMISSION 3'\\^
aE vv ASHINGTON, D. C. 20555 5
stP 5 1979 MEMORANDUM FOR:
G. Zech, Tech Assistant, Division of Operating Reactors FROM:
G. Lainas, Chief, Plant Systems Branch, Division of Operating Reactors
SUBJECT:
DISCUSSION TOPICS FOR JAPAN /U.S. MEETING ON NUCLEAR SAFETY Per your request, the following are some items tnat can be included in the subject meeting.
1.
Mark II Full Scale Condensation Tests.
There are some full scale BWR tests being conducted in Japan.
These tests are related to determining the pool dynamic loads.
For this kind of containment, the domestic containment designs are very similar and the information should indeed be applicable.
2.
Fire Protection. This is a connon area of concern, and an exchange of information, would indeed be valuable.
Some specific areas would be separation requirements, bunkered systems, alternate shutdcwn systems and testing of Fire Protection systems.
3.
Diesel Generator Reliability.
Attached is a su unary of our programs.
S
.G. Lainas, Chief Plant Systems Branch Division of Operating Reactors cc:
R. Ferguson E. Adensam C. Grimes F. Clemenson 7910020 7 % o
s SUMJGRY OF PROGRAM ON ENHANCEMENT ON OH-SITE DG RELIABILITY The University of Dayton Research Institute has concluded a program cesigned to previde NRC/ DOR with technical assistance in evaluating the factors leading to impreved reliability of on-site emergency diesel generator (DG) units.
The program consisted of a comprehensive review of DG maintenance and operating experience and a comparative evaluation of the DG manufacturer's recermendations. This ir.for-matien, will enable the NPC to improve the basis on which it makes regulatory decisions.
The primary goal of the program is to better identify the main problem areas which decrease the reliability of the DG units.
Information was ' collected from a number of seurces:
a crevious NRC reliability study; licensee event reports (LER), from 1959 through late 1977; operating n0 clear power plant licensee respenses to a questionnaire; visits to twenty cperating units and four engine manuf acturers.
Informatien was also cbtained from a cceprehensive literature search, visits to two non-nuclear large-scale users of standby emergency diesel generator' units, and from the applicable HRC Regulatory Guides, NRC Standard Review Plans, NRC Branch Technical Positions, Coce of Federal Regulations, and IEEE Standards.
A total of b32 events were reported in 592 LERs.
Engine problems and Problens engine related problems caused 57.4 percent of these events.
strictly electrical in nature initiated 25.8 percent of the reported events, while the remaining 15.8 percent were general item events.
I Pany of the engine-related problems were associated with the electrical i
monitoring and safety functions.
Purely mechanical problems were relatively few.
Those items categorized as general are basically
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! l people oriented."
I The visits to the nucidar power plants provided an opportunity to i
E observe operating conditions, DG system and subsystem configurations, and facility configuration.
Discussions with plant operating and mainten-i I l-F ante personnel clarified some of the information contained in the LERs and the questionnaire responses. The visits to the engine manufacturers provided a better understanding of generic problems. -their recommendatiens and other important considerations on the operation and maintenance of standby emergency diesel engines.
Based on the above, the main problem areas haveobeen identified and categcrized into three groups as a function of their relative significance.
Tney are as follcws:
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Most Significant Problers a) Meisture In the Air Starting System b)
Dust and Dirt in Diesel Generator Compartments c) Turbocharger Gear Drive Changeever d)
Persennel Training II.
Significant Problems a)
Length of Pre-lube Time b) Testing Test Loading & Preventative Mair.tenance c)
Improve the, Identification of Root Causes III.
Additional Preblems a)
D.G. Room Ventilatien and Cembustien Air Intake Systers b)
Foal Sterage and Handling c) high Tercerature Insulation For Generator Cverload Conoitiens d)
Engine Ccoling Water Temperature Control e)
Concrete Dust Control f)
Vibration of Instruments and Controls The program objectives have been met in that, in addition to identifying the major sources of diesel generator nalfunctions, the report rakes specific and practical recommendations. With these NRC and the utilities can, where appropriate, modify their existing practices and thereby improve.the reliability of the on-site emergency deisel generators.
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