ML19345F002
| ML19345F002 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 01/28/1981 |
| From: | Kay J YANKEE ATOMIC ELECTRIC CO. |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| FYR-81-16, NUDOCS 8102060504 | |
| Download: ML19345F002 (2) | |
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+YAliKEE ATOUIC ELECTRIC COMPANY
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January 28, 1981
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[I' United States Nuclear Regulatory Commission g;,
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Attention :
Mr. Dennis M. Crutchfield, Chief S
3I c3 Operating Reactor Branch #5 s
Division of Licensing
Reference:
(a) License No. DPR-3 (Docket No. 50-29)
(b) USNRC Letter to YAEC, dated November 7,1980 (c) USNRC Memorandum for D. G. Eisenhut from S. B. Hosford, dated April 21,1980, " Summary of a Meeting with the Westinghouse Owner's Group on Mechanistic Pipe Break Study (WCAP 9558)"
(d) Westinghouse Letter to USNRC dated June 30, 1980, NS-TMA-2200 (e) YAEC Letter to USNRC dated May 28, 1980 (WYR 80-58)
Subject:
Yankee Nuclear Power Station LOCA Loads
Dear Sir:
In response to Reference (b), we believe that there exists sufficient justification for our termination of work efforts to determine the radiological impact assoc!.; tad with implementing LOCA restraints. Our position is that, a deta'. led ccat/ burden analysis is unnecessary'since preliminary e'.aluatiant indicate that such modifications are impractical for Yankee Rowe. Spending valuable and limited resources proving the point is wasteful of such resources at a time when other more significant issues require resolution. This is particularly true since NRC staff assessments on the likelihood of a double ended guillotine break and the staff's position on
" leak detection before break" seems to obviate One need for the installation of these restraints, much less a study to determine their location, costs and increased worker exposure.
The commitments referred to in Reference (b) were made before the significance of the results of Westinghouse's Mechanistic Pipe Break evaluation (WCAP 9558) was realized by the Westinghouse utility group-or _ the NRC staff. Subsequently, the NRC staff acknowledged in Reference (c) that
...a substantial effort towards demonstrating.that the leak before break position has been accomplished." As a result of the SEP Owner's _ Group meeting on May 14,'1980 which presented the staff's interim' criteria on high energy _
pipe breaks, we terminated our efforts relative-to installation:or LOCA -
restraints, and the study of the. economic and radiological' burden of such an.
installation.. We informed the NRC staff of our - position in Reference (e).
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United States Nuclear Regulatory Commission January 28, 1981 Mr..Derinis M. Crutchfield, Chief Page 2 The rationale is clear - there is no reason to study the burden resulting from a plant modific ition to preclude the effects of phenomena which is being technically demonstrated not to occur (as previously postulated).
- Hence, stemming from the additional technical information (in WCAP 9558 and subsequent related reports) and resulting understanding that leak before break, rather than instantaneous pipe rupture be postulated, the pursuit of-pipe rupture restraint design, installation and study of burden were recognized as being academic.
The undertaking of a cost / burden study is not a simple task, if done properly.
A study of this nature involves substantial analysis to define the restraint locations, and then extensive work is required to evaluate, design and engineer the restraint configurations. The only simple task is perhaps in pricing equipment fabrication and installation costs. We believe that if this cost / burden study were performed the results would show little difference from the study performed by the Southern California Edison Company for San Onofre Unit 1, and would not disprove our belief that modifications.would be excessive in terms of cost and unreasonable to install due to geometry limitations and radiation' exposure considerations.
Therefore, we request that you reconsider your position that we must re-initiate efforts to determine the radiological impact associated with implementing LOCA restraints. You should have adequate justification of our conclusion on the Yankee Atomic Electric Company docket.
Reference (d) which transmitted reports prepared by the Westinghouse Electric Corporation for the Owners Group should be considered as parfe of the YAEC docket. We believe that because of the substantial significance of the results of the Westinghouse Mechanistic Pipe Break evaluation -(WCAP 3558) and the Staff's acknowledgement of this significance, that a cost / burden evaluation would be an unnecessary exercise. Spending valuable engineering time proving an obvious point makes little sense particularly if a technicalli acceptable alternative approach to LOCA loads exists.
We anxiously await your response _ to our request.
If you have any questions, please contact us.
Very truly yours, YANKEE ' ATOMIC ELECTRIC COMPANY J. A. Kay Senior Engineer - Licensing