ML20207D454
| ML20207D454 | |
| Person / Time | |
|---|---|
| Issue date: | 12/24/1986 |
| From: | Rubin A Office of Nuclear Reactor Regulation |
| To: | Speis T Office of Nuclear Reactor Regulation |
| References | |
| REF-GTECI-A-44, REF-GTECI-EL, TASK-A-44, TASK-OR NUDOCS 8612310015 | |
| Download: ML20207D454 (3) | |
Text
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( i DEC 2 4 W p
( MEMORANDUM FOR: Themis P. Speis, Director Division of Safety Review & Oversight THPU: Warren Minners, Chief Reactor Safety Issues Branch l Division of Safety Review & Oversight FROM: Alan Rubin, Senior Task Manager Reactor Safety Issues Branch Division of Safety Review & Oversight
SUBJECT:
SUMMARY
OF MEETING WITH NUGSB0 ON USI A-44 Date December 18, 1986 Location: Bethesda, Md.
Attendees: NRC NUGSB0 W. Minners S.Maloney(Devonrue)
P. Norian M. McGarry (Bishop, Liberman, A. Rubin Cook, Purcell & Reynolds)
P. Barnowsky M. Childers (Northeast Utilities)
H.Wyckoff(EPRI)
REFERENCE:
(1) Letter to Chairman Palladino from J. H.
Miller,NUMARC, June 17, 1986 BACKGROUND: NUMARC proposed the following four industry initiatives to resolve the station blackout issue (Ref. 1):
- 1. Each utility will review their site (s) against the criteria specified in NUREG-1109, and if the site (s) fall into the category of an eight-hour site after utilizing all power sources available, the utility will take actions to reduce the site (s) contribution to the overall risk of station blackout. Non-hardware changes will be made ,
within one year. Hardware changes will be made within a reasonable time thereafter.
- 2. Each utility will implement procedures at each of its site (s)for:
- a. coping with a station blackout evenc,
- b. restoration of AC power following a station blackout event, and
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- c. preparing the plant for severe weather conditions, such as hurricanes and tornados to reduce the likelihood and consequences of a loss of offsite power and to reduce the overall risk of a station blackout event.
- 3. Each utility will, if applicable, reduce or eliminate cold fast-starts of emergency diesel generators for testing through changes to technical specifications or other appropriate means.
- 4. Each utility will monitor emergency AC power unavailability utilizing data utilities provide to INP0 on a regular basis.
The purpose of this meeting was to discuss (1) NUGSB0's approach to implement initiative 2.a (procedure for coping with station blackout), and (2) the status of the four initiatives.
DISCUSSION: The focus of this meeting was on a discussion of initiative 2.a. NUGSB0 has prepared a draft guidance document for this initiative, but it is not yet completed. The purpose of this document is to provide detailed guidance for utilities to use when developing plant-specific procedures for station blackout. NUGSB0 will give a copy of their guidance document to NRC for review when the draft is completed.
Two alternative approaches are being proposed by NUGSBO, either one of which could be chosen by a utility. The first would allow a utility to develop procedures to use an alternate power source that could provide the power necessary to maintain the plant in a stable condition in the event that all offsite and Class IE onsite emergncy AC power sources were lost (i.e.,
defined as station blackout in USI A-44). The NUGSB0 guidance document would provide criteria that this alternate source of power must meet in order for this approach to be acceptable.
Among these criteria probably would be separation; independence; no common mode failure potential with offsite power or the Class IE onsite emergency AC power sources; equipment reliability; maintenance and testing; and capacity to provide adequate power for all essential loads.
The second alternative is for utilities to develop procedures to maximize the capability of the plant to cope with a station blackout, as defined above, with equipment independent of AC power. At the present time, NUGSBO, has not specified any specific time limit to be established for this coping capability.
V DEC 2 41986 The status of the other NUMARC initiatives is discussed below.
In response to a letter from NUMARC almost, all utilities have reviewed their plants in accordance with initiatives 1 and 3. NUGSB0 is in the process of reviewing the utility responses. When this review is complete NUGSB0 will share the results with the NRC staff.
Initiative 4 is part of an INP0 pilot program to monitor unavailability of safety systems at nuclear power plants.
NUGSB0 will make arrangements will be made for INP0 to brief the staff on this program in the near future.
NUGSB0 has formulated draft guidance documents for initiatives 2.b and 2.c. These will be developed further once the guidance for initiative 2.a is completed.
It is not clear yet whether or not the NURMARC initiatives would meet all the requirements and guidance of the proposed resolution of USI A-44. We expect another meeting will be held with NUGSB0 in late January after NUGSB0 has developed further their guidance on initiative 2.a.
/S Alan M. Rubin, Senior Task Manager Reactor Safety Issues Branch Division of Safety Review & Oversight cc: V. Stello H. Denton R. Vollmer Distribution Central File f - - G i ARubin WMinners PBaranowsky JFlack PDR RSIB R/F PNorian BSheron MTaylor ARubin c/f *See previous concurrence.
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