ML20077F787
| ML20077F787 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 07/28/1983 |
| From: | Harrington W BOSTON EDISON CO. |
| To: | Vassallo D Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.K.3.18, TASK-TM 83-199, NUDOCS 8308030040 | |
| Download: ML20077F787 (2) | |
Text
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e n o BQBTON EDISCN COMPANY 900 BOVLaTON STREET MOsTON. M AssACHusETTs 02199 WILLIAM O. HARRINGTO N SENIOR vegg PSSSIOSNT M...
BECo Letter No.83-199 July 28, 1983 Mr. Domenic B. Vassallo, Chief Operating Reactors Branch #2 Division of Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.
20555 License No. DPR-35 Docket No. 50-293
Subject:
NUREG 0737 Item II.K.3.18 ADS Logic Modifications
References:
( A) NRC Letter dated June 3,1983, NUREG-0737, Item II.K.3.18, ADS Logic Modifications.
(B) BWROG Letter (#8260) to D.G. Eisenhut, dated October 28, 1982, "NUREG-0737, Item II.K.3.18, Modification of ADS Logic."
(C) NRC Letter dated October 31, 1980, Post TMI Requirements.
(D) BECo Letter dated May 8, 1981.
Dear Sir:
Reference (A) inferred that Boston Edison Company supports the Reference (B) study on ADS actuation logic and as such should choose one of two modifications found acceptable by the staff.
Please be advised that Boston Edison Company has never endorsed this study.
The cover letter transmitting Reference (B) handled the issue of endorsement through the inclusion of the following statement:
"The enclosed report, including its conclusions, has been endorsed by a substantial number of the members of the BWR Owners' Group; however, it should not be interpreted as a commitment of any individual member to a specific course of action. Each member must formally endorse the BWR Owners' Group position in order for that position to become the member's position."
Reference (D) provided our response on the subject issue which stated:
" Boston Edison Company believes that the current Pilgrim Station ADS logic design coupled with implementation of the sympton-oriented Emergency Proce-dure Guidelines will satisfy the NUREG 0737 requirements of assuring adequate core cooling during the events in question. This position is formulated on the fact that events of this type are slow, uncomplicated and familiar tran-sients for which the operator is extensively trained and for which he is familiar with both the equipment response and the overall system response I
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COETON ED120N COMPANY Mr. Domenic B. Vassallo, Chief Page 2 and behavior.
Because of this familiarity, the reliability of the operator to perform the required actions is high, to the point of being reflexive.
Sufficient time is available (30 to 40 minutes) to assess the overall plant situation and initiate blowdown if required. The current design also allows the operator the flexibility to control the systems as required by the plant conditions and symptoms and in addition, the Emergency Procedure Guidelines, when implemented, will provide further specific guidance on when to initiate ADS."
Looking back at this NUREG item, Reference (C) identified the need to eliminate manual actuation of the ADS. The objective being, to assure adequate core cool-ing for those highly improbable degraded events which do not directly produce a high drywell pressure signal and are accompanied with a loss of all high pressure coolant injection systems.
Satisfying the NUREG-0737 Item II.K.3.18 guidelines may be accomplished in two ways: The ADS logic may be modified to provide further assurance of adequate core cooling for these additional events, or the operator may be given specific guidance and training for performing manual actions under these conditions.
Implementation of symptom-oriented Errorge icy Procedure Guide-lines will improve the operator response to degraded tran > v.ats by giving him explicit guidance under these conditions.
Therefore, we believe the existing ADS design and implementation of the Emergency Procedures satisfies this NUREG-0737 item and no modifications are proposed or planned.
Ver truly o s,
TMT/ mat
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