ML20127C557
| ML20127C557 | |
| Person / Time | |
|---|---|
| Site: | Mcguire, McGuire, 05000000 |
| Issue date: | 03/08/1985 |
| From: | Bosnak R Office of Nuclear Reactor Regulation |
| To: | Novak T Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML082410334 | List: |
| References | |
| FOIA-85-243 TAC-54822, TAC-54823, NUDOCS 8503150174 | |
| Download: ML20127C557 (4) | |
Text
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'o, UNITED STATES
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NUCL AR REGULATORY COMMISSION
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/,. r WASHINGTON,0. C. 20555 l
MAR 8 1985 MEMORANDUM FOR: Thomasb.Novak,AssistantDirector for Licensing i
Division of Licensing
. FR0ft:
Robert J. Bosnak, Acting Assistant Director for Components and Structures Engineering Division of Engineering
SUBJECT:
REQUEST FOR CHANGE TO TECHNICAL SPECIFICATIONS REQUIRE!iENTS - MCGUIRE NUCLEAR STATION, DUKE POWER COMPANY (TAC # 54822, 54823) l
Reference:
1, Letter frem H. B. Tucker, Duke Power Co. to H. R.
Denton dated April 12, 1984 l
- 2. Letter from. H. B. Tucker, Duke Power Co. to H. R.
Denton dated January 7, 1985 The Mechanical Engineering Branch (MEB) has reviewed the infor: ration submitted
,. by the Duke Power Company in the referenced letters.- Our evaluation of the submittal is~1ttached.
This memorandum supersedes the memoranoum from Knight to Novak dated August 7, 1954 and completes the MEB action on TAC #54822 and 54823.
Ro Actirig Assistant Director for' Components and Structures Engineering Division of Engineering
Attachment:
As stated
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cc:
J. Knight, DE l
F. Cherny, DE l
E. Adensam, DL j
D. Hood, DL l
\\< E. Butcher, DL
.H. Brammer, DE H. _Shaw, DE 4
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.f SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO OPERATION OF MCGUIRE NUCLEAR STATION, UNITS 1 AND 2 DUKE POWER COMPANY DOCKET NOS. 50-369 AND 370 1
Introduction In letters dated April 12,1984 (Reference 1) and January. 7,1985 (Reference 2),
the Duke Power Company submitted a request for a change to the Technical Specifications requirement for the inservice testing of safety-related snubbers in McGuire Nuclear Stations Units I and 2.
In addition to three well defined sampling plans in Section 3/4.7.8 of the Te'chnical Specifications, McGuire Units 1 and 2 are also required by Specification 4.0.5 of the Technical Specifications to follow the rules of ASME B&PV Code Section XI.
The licensee is requesting relief from the Section XI requirements.
Discussion of Evaluation The purpose of the Technical Specifications required functional testing on safety related snubbers is to assure that systems anh components are protected
.against design dynamic events.
Early operating reactors have as many as three or four hundred snubbers.
To test all of these snubbers during every refueling outage was not practical as it would lead to excessive radiation exposure to workers and other undesirable effects.
For this reason, a sampling plan which required testing 10% of the total snubber pnpulation during each refueling outage was permitted for all operating reactors. The same requirement was also endorsed by the ASME B&PV Code Section XI.
Modern reactors
- employ many more snubbers than the earlier plants. This made the 10% sampling )lan impractical since 10% may mean as many as 250 snubbers would have to be tested in some plants.
Statistical studies were made and other sampling plans more practical for plants with large number of snubbers were developed based on these studies.
In addition to the 10% sampling plan, Standard Technical Specifications delineated two of these newer sanpling plans as alternative testing options which provide greater than 95% confidence level that 90% or more snubbers will be operable.
This permits the licensee to select one saccling plan for snubber functienal tests from the three delineated plans, while, the ASME Section XI has only the 10% sampling plan for every user to follow._
Conclusion The staff is cf the opinion that the present Technical Specifications provide ade:uate coverage for the sampling requirements and that the Section XI saccling plan in Specification 4.0.5 is redundant to Section 3/a.7.8 of the Technical Specifications and is impractical for the McGuire Units.
The sampling plan adopted by McGuire Units provides acceptable protection for the e
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systems and components.
The staff recommends that the requested Technical
. Specifications revision be approved. Specification 4.7.9 in the McGuire Units 1 and 2 Technical Specifications should be revised to read:
"4.7.9 Each snubber shall be demonstrated OPERABLE by performance of the following augmented inservice inspection program in lieu of the requirements of Specification 4.0.5."
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References ~ ~
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- 1. Letter from H. B. Tucker, Duke Power Co., to H. R. Denton dated April 12,1984
- 2. Letter from H. B. Tucker, Duke Power Co.., to H. R. Denton dated January 7, 1985 O
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