ML20125D098
| ML20125D098 | |
| Person / Time | |
|---|---|
| Site: | Millstone, Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 12/27/1979 |
| From: | Harold Denton Office of Nuclear Reactor Regulation |
| To: | Counsil W CONNECTICUT YANKEE ATOMIC POWER CO. |
| References | |
| TASK-10, TASK-15-02, TASK-15-2, TASK-RR TAC-42410, NUDOCS 8001140039 | |
| Download: ML20125D098 (2) | |
Text
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DI,STRIBUTION:
Docket File (2) w/inc.
DEisenhut NRCPDR(2)w/inc.
RVollmer L PDR w/inc TJCarter ORB #4Rdg RReid NRR Rdg LShao Dockets Nos. 50-213 25 NSIC JRMiller g p~
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Mr. W. G. Counsil, Vice President DVassallo Dross Nuclear Engineering & Operations DMuller DZiemann Connecticut Yankee Atomic Power Company RMattson PShea and Northeast Nuclear Energy Company OELD HSmith P. O. Box 270 CCA(0)
SECY 793226 GErtter (ED0 7937)
Gray File Rm. 330 (2)
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Hartford, Connecticut 06101 t
MGroff Green Ticket File
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De'ar Mr. Counsil:
MStein w/inc. Rm. 330 Ne umje c.10 Your letter of D :;n r /1979 to Chaiman Hendrie which discussed a number of concerns related to the requirement for an automatically initiated auxiliary feedwater system (AFWS) at the Haddam Neck Plant and Millstone Unit No. 2 facilities has been directed to this office for reply.
This response should not be construed as a detailed reply to each of the concerns expressed in that letter.
On September 13, 1979, a letter was issued by the NRC to each power i
reactor licensee which defined a set of short-tem requirements resulting from the NRC staff investigation.
On October 30, 1979 another lecter was issued clarifying certain staff requirements and their corresponding implementation schedules, and indicating those items requiring prior NRC review and approval.
This second letter indicated that for those items requiring prior NRC approval, your design details should be submitted in a timely manner so that this approval and your implementation of the item can be completed by the required date.
One such item was 2.1.7a, which requited automatic initiation of the AFWS by January 1,1980. The purpose of *.his letter is to set forth our position regarding short-tem recomendations 2.1.7a on the Haddam Neck and Millstone Unit No. 2 facilities.
Your letter of December 3,1979 indicated that Connecticut Yankee Atomic Power Company (CYAPC0) and Northeast Nuclear Energy Company (NNECO) have detemined that implementation of the requirements of 2.1.7a, without incorporating automatic isolation in the event of a steam or feedwater line break which is a feature not required by item 2.1.7a, would constitute an unreviewed safety question pursuant to 10 CFR 50.59.
You stated that for both Haddam Neck and Millstone Unit No. 2 implementation of an auto-matic AFWS without the isolation feature would, for a steam line break, accident, result in a positive reactivity insertion in excess of that docu-mented in current safety analyses potentially resulting in a return to criti-cality.
In addition, you stated that for this case, there would be increased mass and energy released to containment.
As a consequence, the potential exists for a more severe condition considering both containment integrity Ed cFli rOI."iC.Nal Qu5lifiG6 tion Saa lu cu rTeni.ly dpprOVed a ldlyses.
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- We ve evaluated this infomation and have reached the anclusion that fo he Haddan Feck and Millstone 2 proposed designs,.creo,' for operator actig to isolate the autotatically initiated AFWS flow to a failed steam generator is the sare as credit for operator initiation of the present nanualsstart AFks. We find that if a problem exists with safety evaluations for the'nain steam line/feedwater line break accidents, it also exists for the current man a1 start AFWS case. Therefore, you are requested to provide an aralysis of the effect of failure to isolate feedwater flow to the affected steam generator in' the event of a nain stean line or feedwater line break assuming early initiation of the auxiliary feedwater system. This a alysis should be provided promptly to allow resolution of this question ir sufficient time to meet the implerentation schedule.
With regard to your 10 CFR 50.59 determination, we accept your finding, This means that our review and approval of your nodification is required prior to ir@lenentation which is exactly what is required by our letter of l
October 30, 1979.
You should reevaluate ycur overall approach and develop alternative strategies to meet the staff recommended goal of implementing an approved AFWS design.
We are available to neet with you at an early date to discuss these matters further.
i Sincerely, Original signed by Darrell G. Eisenhtit Harold R. Denton, Director Office of Nuclear Reactor Regulation 90023270 C-0RBf2:00R B&0TF:00R-D DZiemann*
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We have evaluated this information and have reached the conclusion that for the Haddam Neck and Hillstone 2 proposed designs, credit for operator action to isolate the automatically initiated AFWS flow to a failed stean generator is the same as credit for operator initiation of the present manual start AFWS. We find that if a problem exists with safety evaluations for the main steam line/feedwater line break accidents, it also exists for the current manual start AFWS case.
Therefore, you are requested to provide an analysis of the effect of failure to isolate feedwater flow to the affected steam generator in the event of a main steam line or feedwater line break assuming early initiation of the auxiliary feedwater system.
This analysis should be provided promptly to allow resolution of p
this question in sufficient time to neet the implementation schedule.
As a result of this concern, the staff presented to the Commission a proposal to s
delay full implementation of automatically initiated AFWS flow until January 31, 1980.
s With regard to your 10 CFR 50.59 determination, we accept your finding.
This means that our review and approval of your nodification is required prior to irplementation which is exactly what is required by our letter of October 30, 1979.
You should reevaluate your overall approach and develop alternative strategies to meet the staff reconnended goal of inplementing an approved AFWS design by Janua ry 31, 1980. We are available to r.eet with you at an early date to discuss these matters further.
Si ncerely, i
Harold R. Denton, Director Office of Nuclear Reactor Regulation N
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,s We have evaluated this infonstion and have reached the conclusion that for the Haddam Neck and Millstone 2 proposed designs, credit for operator action to isolate the automatically initiated AFWS flow to a failed 1
i stean generator is the same as credit for operator initiation of the present manual start AFWS. We find that if a problem exists with safety evaluations for the main stean line/feedwater line break accidents, it also exists for the current manual start AFWS case. Therefore, you are requested to provide an analysis of the effect of failure to isolate feedwater flow to the affected steam generator in the event of a main steam line or feedwater line break assuning early initiation of the auxiliary feedwater system.
This analysis should be provided promptly to allow resolution of this question in sufficient time to meet the implementation schedule. As a result of this concern, the Comission has agreed to delay full imple-mentation of autonatically initiated AFWS flow until January 31, 1980.
With regard to your 10 CFP, 50.59 detemination, we accept your finding.
This means that our review and approval of your modification is required prior to inplementation which is exactly what is required by our letter of October 30, 1979.
You should reevaluate your overall approach and develop alternative strategies to neet the goal of implementing a staff-approved AFWS design by January 31, 1980. We are available to meet with you at an early fate to discuss these ratters further.
Si ncerely, Harold R. Denton, Director Office of Nuclear Reactor Regulation 90023272
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. We have evaluated this information and have reached the conclusion that credit for operator action to isolate the automatically initiated AFWS flow to a failed steam generator is the same as credit for operator initiation of the present manual start AFWS. Therefore, if a problem exists with safety evaluations for the main steam line/feedwater line break accidents, it also exists for the current manual start /,FUS case.
Therefore, you and other similarly designed reactors have been requested t
to provide an analysis of the effect of failure to isolate feedwater flow l
to the affected steam generator in the event of a main steam line or feedwater line break assuming early initiation of the auxiliary feedwater system. This analysis should be provided promptly to allow resolution of tht que';ti's. in sufikient time to meet the implementation schedule of January 1,1980.
With regard to your 10 CFR 50.59 detemination, we accept your finding.
This means that our review and approval of your modification is required prior to implementation which is exactly what is required by cur letter of October 30, 1979.
You should reevaluate your overall approach and develop alternative strategies in order to meet the goal of irplementing a staff-approved AFWS design by January 1,1980. We are available to meet with you at an early date to discuss these matters further.
Sincerely, Harold R. Denton, Director Office of Nuclear Reactor Regulation M
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