ML16245A422
| ML16245A422 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 08/08/1979 |
| From: | Lainas G Office of Nuclear Reactor Regulation |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7908270092 | |
| Download: ML16245A422 (4) | |
Text
MEMORANDUM FOR: A. Schwencer, Chief, Operating Reactors Branch #1, DOR FROM:
G. Lainas, Chief, Plant Systems Branch, DOR
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION - CONTAINMENT PURGE SYSTEM.FOR OCONEE NUCLEAR STATION, UNITS 1, 2 AND 3 (TAC NOS: 10207, 10208 AND 10209)
REFERENCES:
- 1. Letter to H. Denton dated January 5, 1979
- 2. NUREG-0560, "Staff Report on the Generic Assessment of Feedwater Transients in Pressurized Water Reactors Designed by the Babcock & Wilcox Company", dated May 1979 Plant Name: Oconee NuclearStation, Units1l, 2 and 3 Docket Nos.: 50-269/270/287 Generic Task Responsible Branch:
ORB #1 Task Manager: E. Reeves Review Status:
Awaiting Information With regard to the containment purge system at the Oconee Nuclear Station, Unitsll, 2 and 3, the-licensee has-attempted to justify unlimited purging.
Section A,.reviewing fthe electrical.override aspects of containment purging, has no questions at this point in their review. The Plant Systems Branch Section B, after having reviewed the applicable portions of the FSAR and the document (Ref. 1) filed by the licensee, has prepared the enclosed re quest for additional information., We believe the questions raised by Section B should be sent to the licensee without any unnecessary delay.
In the course of our review, Section B has identifiedseveral areas where additional information'is necessary.
Specifically, the following areas were identified as significant review areas:
- 1.
The licensee has not addressed debris which would prevent valve closure.
- 2. The licensee has,not provided an analysis of the reduction in containment.pressure resulting from the partial loss of containment atmosphere during the accident for ECCS backpressure determination.
DISTRIBUTION Central files NRC PDR PSB Reading MEMORANDUM FOR: A. Schwencer, Chief,-Operating Reactors Branch #1, DOR FROM:
G. Lainas, Chief, Plant Systems Branch, DOR
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION - CONTAINMENT-PURGE SYSTEM FOR OCONEE NUCLEAR STATION, UNITS 1, 2 AND 3 (TAC NOS.:
10207, 10208 AND 10209)
REFERENCES:
- 1. Letter to H Denton dated January 5, 1979
- 2. NUREG-0560, "Staff Report on the Generic Assessment of Feedwater Transients in Pressurized Water Reactors Designed by the Babcock & Wilcox Company", dated May 1979 Plant Name:
Oconee Nuclear Station, Units'l, 2 and 3 Docket Nos,.: '50-269/270/297 Generic Task Responsible Branch: ORB#1 Task Manager: E. Reeves Review Status: Awaiting.Information With regard to the containment purge system at the Oconee Nuclear Station, Units 1, 2 and 3, the licensee has attempted to justify unlimited purging.
The Plant Systems Branch Section B, after having reviewed the applicable portions of the FSAR and the'document (Ref. 1) filed by the licensee, has prepared the enclosedrequest for-additional information.
In the course of our review, we identified several areas where additional information is.necessary. Specifically, the following areas were identi fled as significant review areas:
- 1. The licensee has not addressed debris which would prevent' valve closure.
'2.
The licensee has not provided an analysis of the reduction in containment pressure resulting from the partial loss of containment'atmosphere during the accident for ECCS backpressure determination.
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- 3. The licensee has not provided the amount of containmeni atmosphere eleased through the purge isolation,.valves during the time required for them to close following a LOCA.
Furthermore, as indicated in the PSAR, 'the containment purge isolation valves are actuated to close. by either a high containment pressure (4 psig) signal or high radiation signal or both. Per NRC s recommendation (Ref. 2), we will also require the licensee to provide a containment purge valve isolation signal initiated by safety injection actuation.
G. Lainas, Chief Plant Systems Branch Division of Operating Reactors
Enclosure:
As stated
Contact:
D. Shum X-27110 cc w/enclosure:
D. Eisenhut B. Grimes W. Gammill L. Nichols"'
D. Tondi J. Beard E. Adensam E. Reeves D. Shum R. Reid M. Fairtile PSB:DOR SL-SfOP B:DOR DOR:SL PSB OFFCK0 S
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REQUEST FOR ADDITIONAL INFORMATION FOR CONTAINMENT PURGE SYSTEM FOR OCONEE NUCLEAR STATION, UNITS 1, 2 AND 3 DOCKET NOS.: 50-269/270/287
- 1. With regard to the containment purge system, provide the following information:
- a. Discuss the provisions made to ensure that isolation valve closure will not be prevented by debris which could become entrained in the escaping air and steam.
- b. Provide an analysis of the reduction in the containment pressure resulting from the partial loss of containment atmosphere during the accident for ECCS backpressure determination.
- c. Specify the amount of containment atmosphere released through the purge isolation valves during the time required for them to close following a LOCA.
- 2. As indicated in the FSAR, currently, the containment purge isolation valves are au'tomatically closed by either a high containment pressure signal or high radiation signal or both. The experience gained from the TMI-2 accident indicates that a containment isolation signal initiated by safety injection actuation is also needed to close the purge valves. Therefore, provide your plan for modifying the control system to isolate containment whenever safety injection is initiated.