ML19344B370
| ML19344B370 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 07/08/1977 |
| From: | Bolger R COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF THE SECRETARY (SECY) |
| Shared Package | |
| ML19344B371 | List: |
| References | |
| NUDOCS 8010080722 | |
| Download: ML19344B370 (5) | |
Text
{{#Wiki_filter:' ,r ' ',~ . Commor ialth Edison-is- - M / one First Nrmnal P ata. Chicago. Illinoi,s i(
- 7. Addrrs R; ply 10: Post Offica Box 767
\\ N Chicago, Illinois 60690 C[ 9 k N G) [LL lh 4,i July 8, 1977 /2/ RLu Lu M yjL14977? '~t ': H [ g ossim . Secretary of the Commission ' h. U.S. Nuclear Regulatory Commission p-washington, D.C. 20555
Subject:
Dresden Station Unit 1 Request for Extension of Exemption in Accordance with 10CFR50.46 Paragraph (a) (2) NRC Docket 50-10 Gentlemen: Commonwealth Edison Company requests an extension to December 31,-1978 of the expiration dates of the exemption from 10CFR50.46 dated August 21, 1975 and an amendment to the operating license extending to December 31, 1978, the time provided in the-NRC order dated June 23, 1976 concerning IEEE-279, Reactor Protection System (RPS) and Fire Protection System Modifications. The Exemption and Order' allow operation, of Dresden Unit 1 during the period of completing the modi-fications to provide conformance with the Order and the require-ments underlying 10CFR50.46 with respect to diversity and redundancy of emergency systems and power sources. The earliest possible completion date for all these modifications is the first quarter of 1979. The following supporting documents are attached. Attachment #1--Affidavit of J.S. Abel concerning 10CFR50.46 Exemption Attachment #2--Affidavit of R. A. Naatz concerning replace-ment power cost Attachment #3--Affidavit of J.S. Abel concerning NRC Order In our June 18, 1975 exemption request we indicated that there was uncertainty in the design basis and the schedule'for the high pressure coolant injection (HPCI) system. We stated the following: "This' schedule is based on proceeding with immediate procurement of certain critical path equipment using present design specifica-tions. The design specifications are based 801008077M
-(g; *. r e-A ;. g N .Commonwe:lth Edison. t.u
- Secretary o'f)the Commission July 8,J1977 Page-Two on the best estimates of the high pressure' coolant injection (HPCI) system performance required to conform withithe FAC.
The final proof of these . performance' requirements will be obtained from the FAC evaluations 'to -be submitted to the NRC -on August 2, 1975. We believe that the proposed-modifications will~ prove adequate and we are proceeding at our own risk to order certain components-in order;to meet the earliest possible completion date. LIf unforeseen findings during the completion of our. review or the NRC Staff review of these evaluations. indicate that the currently proposed ECCS modification designs are not adequate to conform with the FAC, the schedule for conformance with the FAC could be significantly extended. .We. mention these considerations to identify the uncertainty in the'present ECCS modification schedule and to' point out that the evolution of l the criteria has necessitated modifying' designs to meet a moving target." i. We have proceeded with installing HPCI and the RPS modifications even though the NRC has not completed review of the 10CFR50.46 Final Acceptance Criteria (FAC)' ECCS - analysis, submitted.in August, 1975, the HPCI system design report submitted in October of 1975 or the FEMA analysis * ~ ~ dated November 15, 1976.- We have experienced problems and delays with design,' equipment procurement, and construction. .The. detailed design process has necessitated design changes v!.ich:are being implemented and which have' delayed the project. 'In short, the problems foreseen at the outset are' being~ realized. The NRC has been kept continuously informed of.the progress, problems, and schedule of the HPCI project through the submittal of quarterly progress reports which are attached. ~ -The attached affidavit of Mr. J. S. Abel describes the HPCI I and.on site power supply system additions and modifications, explains the basis for the schedule, provides the justifica-tion'for continued safe. operation of Dresden 1 until December 31, -1978, and presents-the additional actions that Commonwealth . Edison is taking to further assure the health and srety of .the public'during the: extension period. Commonwealth Edison Jis taking these' interim actions on the fastest possible basis so;that~they may be{ completed by December 31, 1977. Because of'this expedited schedule prior NRC review is not possible. Such review is not necessary because these actions are only .for interim protection and'do not raise unpeviewed safety c aquestions. ~
W T,c 4 3 - (.[ tCommonwealth Edison 7(.h ~ A 1 Secretary 1of'the. Commission-July-8,(1977 .Page Three-TheLIEEE 279,-reactor-protection system,and fire protection ~~ modifications which were to be completed by. -December $31,,1977< in-accordance with'the NRC order dated-June'23, 1976 cannot be. completed until' December 31,-1978. Therefore, Commonwealth' Edison Company, with;this submittal, is also requesting an. extension'of the. time allowed in-the 'NRC June'23, 1976 order. Commonwea:.th Edison Company has submitted its proposed modificatiens-pursuant to the June 23, 1976 order. in a January 12, 1976 letter. These commitments are: a)_ . Protect the electrical cable at-the penetrations. and in the cable tunnel from a fire by using automatic fire detector.and water spray systems. b) Upgrade the Unit 1 containment equipment.wh:1ch is required to operate during-or after the postulated LOCA. c) Modify the RPS ix) comply with the. single' failure intent of IEEE-279-1968. ~ ' d) Prepare the Failure Modes and Effects Analysis Report for-the-proposed Reactor Protection System. l The Failure Modes'and' Effects Analysis Report was L submitted'by Commonwealth Edison on NovemberE15,.1976. This j. FEMA shows that no single failure,' loss of power, or'a hot l' short.on the' scram bus will prevent a reaceor-trip. - The NRC has not: yet commented on the FEMA. ' Engineering and procurement are proceeding as i expeditiously as'possible with respect to these modifica-tions. However, due.to complications in the.detailled l i design and;the' desirability of completing certain connections afterfthe planned' chemical. cleaning of the unit to minimize radiation exposures.the completion date will~not be earlier than late 1978 or early 1979. I Withoutia June-July 1977 refueling outage and continua-tion of ' the exemption until. December :31,1978, Dresden Unit:1 l Jwould ' sit? idle or atLvery_ low powerJ1evel for about'a year i with'no' effective. outage related work performed. This situa-
- tion wouldibe especially burdensome considering that we have already1 spent-;or committed over half of-the' estimated-$15,000,000 costcof the HPCI system and $1,000,000 for modifications in responseLto.the.NRC-Order-in1 advance of. approval of our Jdesign. report:or1 performance. analysis.
With the refueling b fo'utage Dresden Unfi l-would be able to maintain a 60%' capacity rfactorffrom. January 1,-1978 to August 31, 1978 or a lower . capacity factor.for-.aflonger.. period of. time. T t '--'=e E = e ,w--- e- -.we-w.- r y 9 -*
n =,- <~ '-{. Commonwealth Edison 2 '(- i. os Secretary-of the Commission
- July 8, 1977'
- Page Four.-
The attached affidavit of Mr. Richard A. Naatz identifies ~the burdens-to Commonwealth Edison and its customers of denying the relief. requested. The. justification for the relief requested is
- similar' to that which.has previously been found adequate.
-Page 3 of August 21,.1975 NRC order states: "These findings were premised upon two principal factors. First, since the. reactor could meet the performance requirements of the IAC under most postulated accident conditions (though required redundancy-of emergency cooling systems and-power sources was missing), reliance was placed on the extremely low probability of loss-of-coolant accident (LOCA) occurring simultaneously with loss of all off site power sources.
- Second, increased assurance with respect to the adequacy of protection was based upon -(a) measures to detect primary coolant leak.] or potential leaks before cracks could propagate appreciably, (b) trebeled in-service inspection frequency, (c) technical specification modifications re-garding the manner of operation and testing of the feedwater pumpsoto provide increased reliability, and' (d) special reporting requirements with respect to continued efforts to upgrade the reactor's ECCS."
A full-Appendix K ECCS analysis of Dresden 1 with existing equipment.was performed and submitted t'o the NRC on July 31, 1975. The analysis. demonstrates that Dresden 1 meets-the. performance requirements of 10CFR50.46 while operating within theLMAPLHGR curves that were generated as a .part of the analysis. We are operating within the MAPLHGR curves and will continue to do so during:the extension period including lany MAPLHGR limits that may be generated for new fuel types that mayfbe used in the core > In addition, Commonwealth Edison is taking additional-actions (see affidavit of Mr.'J.S. Abel) to. increase the reliability of the emergency core cooling systems during the extension period.
r n [.. - d. f ' Commonwealth Edison ' I-Secretary of the; Commission'- i July?8,~1977 ' Page.Five -We believe the' foregoing discussion, the relatively -un que s tuat on of Dresden.1,.the prior. determination, the i i i ~" Plant As'Is" Appendix.K_ECCS analysis,-the additional' measures.- toLimprove-the ECCS reliability, and the attached affidavits demonstrate that;for this unit, the public' interest = favors the exemption _ extension requested. We will attempt.to meet any requests for supplementary information. Very.truly yours, R. L. Bolg. Assistant Vice President i cc E. G. Case V. J. Stello K. R. Goller D.-K. Davis l: J. Sainto l c t: l l I-8 W b .t h-r. y .w 4
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