ML20044H477
| ML20044H477 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 06/03/1993 |
| From: | Barrett R Office of Nuclear Reactor Regulation |
| To: | Lainas G Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20044H478 | List: |
| References | |
| TAC-M86294, NUDOCS 9306090073 | |
| Download: ML20044H477 (2) | |
Text
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ENCLOSURE pR PEGg
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WASHINGTON, D.C. 20555-0001 13 0 3 1993 MEMORANDUM FOR:
Gus C. Lainas, Assistant Director for Region II Reactors nivision of Reactor Projects - I/II Office of Nuclear Reactor Regulation FROM:
Richard J. Barrett, Chief Containment Systems and Severe Accident Branch Division of Systems Safety and Analysis Office of Nuclear Reactor Regulation
SUBJECT:
RESPONSE TO TIA NO. 93 REQUEST FOR TECHNICAL ASSISTANCE IN DETERMINING REGb W vRY BASIS FOR TECHNICAL SPECIFICATION 3/4.9.4, REACTOR BUILDING PENETRATIONS FOR SUMMER PLANT (TAC NO. M86294)
This memorandum is our response to Region II's request for assistance (memorandum from E. W. Merschoff for G. C. Lainas, dated April 14, 1993) in determining the regulatory basis for Technical Specification (TS) 3/4.9.4, Reactor Building Penetrations (Refueling Operations). Specifically, the request involves the use of temporary sealants to close primary containment (reactor building) penetrations during core alterations or. movement of irradiated fuel.
TS 3/4.9.4 states that each penetration providing direct access from the reactor building atmosphere to the outside atmosphere shall be 4
either closed by an isolation valve, blind flange, or manual valve, or be capable of being closed by an operable automatic Reactor Building Purge and Exhaust isolation valve. The licensee had run temporary cables and/or instrument wires through such a penetration to support refueling activities and had sealed up the penetration with temporary sealant (foam and Kaowool).
i for Summer and other plants with the Westinghouse Standard Technical Specifications (STS), the Technical Specification on containment closure during times of fuel movement requires a closed isolation valve, blind flange, l
or manual valve.
This would preclude the use of scalants as a means of meeting this requirement. However, the Bases for this specification
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demonstrates that the intent is to provide a leak-tight barrier, but not necessarily a pressure resistant barrier. We recognized that this intent has e
been satisfied with barriers that do not meet the requirements of the specific TS language in most instances.
Since the practice involved is long-standing and widespread, we do not believe the level of effort that would be required to include more explicit language in the TS justifies an amendment for each plant, as long as the staff's intent is satisfied.
i The Improved Westinghouse STS, Rev. O, dated September 28, 1992, contains the I
added words, "or equivalent," after the list of acceptable isolation barriers in TS 3/4.9.4.
This TS would allow the practice of using temporary sealants to close penetrations during refueling operations if no pressurization is l
predicted.
CONTACT:
J. Pulsipher 504-2811 1
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D As a result of the shutdown risk program, the staff intends to update the requirements related to containment isolation and closure during shutdown. At that time, we should update this section of Technical Specifications to explicitly allow non-pressure-resistant seals for closure during fuel movement, assuming that this remains consistent with the conclusions of the shutdown risk study regarding transients that may potentially pressurize containment during shutdown.
In conclusion, we find that the practice of using temporary sealant and other barriers to close containment penetrations during refueling operations meets the staff's intent as stated in the Bases of the Standard Technical Specifications, when they are properly designed and installed.
f Ric dfrd'ti', Chief Containment Systems and Severe Accident Branch Division of Systems Safety and Analysis Office of Nuclear Reactor Regulation cc:
G. Wunder J. Mitchell A. Gibson, RII E. Merschoff, RII t