ML20236D460
| ML20236D460 | |
| Person / Time | |
|---|---|
| Issue date: | 09/09/1987 |
| From: | Rubin A NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | Serkiz A NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| References | |
| REF-GTECI-A-44, REF-GTECI-EL, RTR-REGGD-01.155, RTR-REGGD-1.155, TASK-A-44, TASK-OR NUDOCS 8710280217 | |
| Download: ML20236D460 (3) | |
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SEP 91987 f
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MENORi1DUM FOR:
AleckW.5erkiz h$T A
. Reactor and Plant Safety; Issues Branch >
FROM:
Alan M. Rubin, Section Leader 9 N M8 b S*'
Human Factors Section 1
-Reliability and Human Factors Branch
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SUBJECT:
REVIEW' 0F NUMARC-8700, !' GUIDELINES AND TECHNICAL' BASES FOR NUMARC INITIATIVES ADDRESSING STATION BLACK 0UT AT LIGHT WATER REACTORS," REV.,0.0,-AUGUST 31, 1987 j
i Per your request of September 1,.'1987, I heve reviewed the subject NUMARC
. document.and have the.followine ceneral comments. NUMARC/NOGSB0 has made' i
significant progress in this latest report in narrowing the technical difference between NRC and' industry. initiative to resolve'USI A-44.
This.is particularly true with the eddition of a fifth in'dustry to assess a plant's station blackout coping capability. This had been a major difference between -
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the NRC staff's and industry's position in the past. NUMARC has also updated the method to categorize a plant's required station blackout coping category
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(e.g, 2, 4, 8 or'16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />) to be censistent with.NRC's revised Regulatory Guide.
1.155, " Station Blackout."
However, before NRC endorses NUMARC-8700, seme modifications are necessary.
I The items on Enclosure 1 are representative of the types of change that should 1
be made, but this list is:not complete. As you requested, 4 cm enclosing a i
copy of NUMARC-8700-(Enclosure ?) with markups of specific pages that should be
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revised.
If these changes are made, the NUMARC document would be technically 1
adequate and should be referenced in Regulatory Guide 1.155. This would:
1 provide a benefit for both the staff and industry by having a consistent set of-guidelines to implenent the resolution of USI A-44.-
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If you have any questions on my comments, I would be happy to discuss them with you.
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M Alan H. Rubin, Secticn Leader
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Human Factors Section l
Reliability and Human Factors Branch i
i cc: w/ enclosure 1 Distribution T. Speis K. Knici DC5; j
B. Sheron P. Nerian RES Chron/ CIRC-i W. Minners P. Baranowsky DRPS Chren File
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F. Coffman RHFB Reading File A. Rubin j
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OFFICIAL RICORD CDPY
v ENCLOSURE 1 Items that Should be Revised in NUMARC-8700
- p. 1-3 Initiative 5 should be revised to include a statement that plant hardware and/or procedural modification will be made, if necer-sary, to successfully demonstrate the 4-hour coping duration.
Section 2.3.? Clarify the discussion in this section.
Some of the statements can be misleading and do not accuretely represent the NRC staff's technical documents on USI A-44.
(See Enclosure 2 for specific recommendations.)
pp. 2.1, 2.5 The recovery period after AC power is restored should be and 7.6 included in the general criteria statement, the assumptions on the station blackout (SB0) transient, and the method for assessing statien battery capacity.
Sectior 2.5 The basis and statements on reactor coolant pump seal leakage do not accurately reflect current NRC staff position on Generic Issue 23 and should be revised.
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Tables 3-1 There is insufficient technical basis to reduce a plant's and 3-2 extremely severe weather group as specified in the footnote.
I have suggested an alternative statement in Enclosure 2 that could be supported.
Section 3.2.3 Individual EDG reliability should be used instead of the and 3.2.4 average reliability for all EDG's at the unit to deternine the SB0 coping duration category.
Section 3.2.4, The EDG reliability program shculd include monitoring EDG 6.2 and reliability and improving the reliability if the target level Appendix D is not achieved,
- p. 7-3 and Water sources and supplies from adjacent units should not be 7-10 considered available during a SB0 for a multi-unit site with a 1/2 EAC configuration since both units would be blacked out.
- p. 7-14 Prccedures for SB0 should include operator actions necessary to l
enhance cooling for roons identified as Region 2.
- p. 7-16 Supportina technical basis should be provided to show, with reasonable assurance, that opening instrument cebinet doors will provide sufficient cabinet cooling during a SBO.
Appendix B, The report states that the "AAC power system shall be sized to
- p. 8-2 carry the recuired shutdown loads for at least 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />."
If a plant is in an 8-hour or 16-hour coping duration group, the l
AAC source should be capable of providing power for required loads for at least 8 or 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> respectively.
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At multi-unit sites with 1/2 shared or 2/3 EAC configuration, an adjacent unit's Class 1E power source should not be considered as an AAC power. source.
Appendix E No information on the methods to analyze the effects of loss of ventilation under'SB0 conditions or previded. Therefore, I
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cannot provide comments. This appendix should be completed before NRC endorser all of NUMARC-8700.
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