ML17192A500
| ML17192A500 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 01/16/1979 |
| From: | Ziemann D Office of Nuclear Reactor Regulation |
| To: | Reed C COMMONWEALTH EDISON CO. |
| References | |
| TASK-04-01.A, TASK-4-1.A, TASK-RR NUDOCS 7901250256 | |
| Download: ML17192A500 (6) | |
Text
_'ti-JAN l 6.1979 OocketN~~ *
~
Mr. Cordell Reed Assistant Vice President Cor1monr1ealth Ediso_n Company Post Office Box 767 Chicago, Illinois 60690
Dear 1-lr. P.eed:
Enclosed are copies of our draft evaluation of Systematic Evaluation -
ProqraM topic IV-1.A, aOperation With Less Than All Loops in Service.*
You-are requested to exar.iine the facts upon which the staff has based its evaluation and resrond either by confiming that the facts are correct, or hy identifying any errors. If in error, please supply _
corrected i nfonnation for the docket.
We encourage you to supply for thP. docket any other material related to these topics that might affect the st~ff's evaluation *
. It would be h~lpful if your connents \\'iere received wi.thin 30 days of the date you receive this letter.
Enclosures:
Topics IV-1.P.
cc w/enclosures:
See next page DOR:ORB#2 Sincerely, Origfha:i_ S5.",'n-':~ bTI"*
Dennis L.
z~0~~~n Dennis L. Ziemann, Chief Ooeratino Reactors-Branch #2 o1vi sion_, of Operating Reac-tors DISTRIBUTION:
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- ~-rr. Cor_:::e1 l Reed
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- l*~r. John '*J. RO\\'/e Isham, Lin~oln &.Beale.
- *.CounseJ or.s at *Law
- One first Uational Plaza, 42nd Floo~
~' Chica~6, Illinoi~ 60603 M~. B. B *. Steph~nsbn Plant Superintendent O~esden Nuclear Po0er Station Rural Route #1 Morris, Illinois 60450 Anthony Z.
Rois~ari N~tural Resources Defense Council 917 15th Street, N. W.
\\*/ashington, D.. c.
20005 U.S. Nucl.ear Regulatory Commission ATTN:
Jimmy L. Barker
? ** 0. Box* 706.
Morris, Illinois 60450 Susan N. Sekuler.
- Assistant Attorney General Environmental Control. Division 188 \\.!. Randolph Street Suite 2315 Chicago, Illinois 60601 Morris ?ublic Library_
- 604 Liberty Street.
Morris, Illinois 60451 K MC Inc.
ATIN:
Mr.. Jack McEwen 1747 Pennsylvania Avenue, N.W~
Suite 1050 Washington~ D. C.
20006
.. *January 16, 1979.
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. SYSTEMATIC *EVALUATION PROGRAM.
Topic IV-I-A:
- Operati.on with l~ss than all loops in service,
.. ***PLANT:.Dresden Station Unit l
. Discussion I
The majority of the presently operati.ng BWR 's and. PWR 's are desjgned to pennit operation with less than full reactor coolant flow. That ts, if a PWR reactor coolant pump or a BWR recirculation pump becomes inoperative,*
the flow provided by the remaini.ng loop or loops is suffi~ient for steady state operation at some definable power level, usually less than full power.
Plants authorized for long tenn.operation with one reactor coolant pump out of. service have. submitted, and the staff.. has approved, the necessary ECCS.* steady. state, and transient analysis. The remaining PWR and. BWR 1 icensees.have Technical Specifications wh.ich require a reactor shutdown
- withiri 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> if one of the operating loops becomes inoperable and
- cannot be returned to operation within the time period.
Evaluation *
- The docketed material for Dresden l has been reviewed with respect to
.*.operation with le~s than all loops in service. Dresden Unit 1 is a four
- .loop General Electric design Bo.il ing Water Reactor (BWR) which is author-
. ized to operate in an n-1 and n.. 2 (3 loop and 2 loop) configuration.
Authorization to operate with less.than.all loops in service was granted as *part of the evaluatfoh supporti.ng the reload review for cycle ll operation (staff.SER dated September 20, 1977). Although not specifically cited in that evaluation, the review and approval of the maximum average II
planar linear heat generation r*ates {MAPLHGR)*.considered operation in the 4 loop~ 3 loop,* and 2 loop configuratio~s.. This ~onsideration was *.
~.
based on the informa.tion provided by Corranonwealth* Edison {letter dated
. S~ptember 8, 1977} i~ response.to a staff request for additional infor-mation.
Part of the information sub~i'tted add.ressed the staff is c()ncerns associated ~fth operation with less than all loops in service {i.e., ECCS, ste.ady state, and transient opera ti oh in the n-1, n-2 1 oop modes).
The
-Licensee further proposed Technical Specification 3.. 5.12.B and Technical
- Specificatfoil figur~s 3.5.1 through 3.5.4 *which assure that the appro-priate MAPLHGR:reductions are 'employed when operating in the reduced*
loop mode.
These changes provide further assurance of continued reactor operation that is acceptable with respect to ECCS performance criteria in all mode.s of operation {4 loop, 3 loop, 2 loop).
These Technical*
. Specifications w~re approved, based on our review of the analysis per-formed by.Commonwealth Edison, dated September 20, 1977.
Amendment 21 additfonally app~oved Technical Sp~cifications, agreed upon.by the licensee, to limit the maximum thermal power level of the reactor during each mode of reduced loop opera ti on { 4.1 oop ful 1 power ii 3 1 oops 525. mwt' 2 1 oops 350 mwt'.
less than 2 loop.operation is not permitted). Although the reasoning for these limits is different than those considered for n'."" 1 loop operation *
(Amendment *21, 9/20/77, para. 2.6)-the resultant provides an additional margin of safety.. That is,_ s i nee the power 1eve1 is 1 imi ted (depending
- on the loop confi.guration} the stored energy of the fuel is. limited.
proportionally resulting in peak clad temperatures less than. those previously' calculated.
We therefore conclude* that Commonwealth Edison. *
- has provided sufficient justification.for Dresden Unit 1 to operate for
- prolonged periods of.time with less than all loops.. inservice.
On this.
basis we conclude that Topic IV-I:-A is satisfactorily completed and re~olved.
..:~ /
SYSTEMATIC EVALUATION PROGRAM
- Topic IV-I-A:
Operation *W.ith less than all. loops in. service,*
PLANT:* Dres.den *.Sta ti on Uri if 2 Discussion
- s are des.igned to*
permit operation with.~less than full reactor coolant flow~ That is,
- if a PWR reactor coolant pump or a BWR rectrculatton pump becomes inope~ative, the fiow provided~by the.remaining loop or loops ts
- sufficient for steady state ope~ation at some definable power level, usually less than full power.
Plants authorized.for. long term operation w1th one reactor coolant pump
- out ()f service have submitted, and. the staff has approved, the necessary.-
ECCS, steady state~ and transtent analysis, The remaining PWR and BWR
. licensees have. Technical. Spect.fications which require* a reactor. shutdown within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> if one of the operating loops becomes *inoperable and cannot be returned to operation withtn the time period, Evaluation The docketed.material for Dresden Station Unit 2 has been reviewed wtth.
.respect to operation with less than all loops in service, Dresden 2 is a two loop General Electri'c design, pressure..:.suppressi'on type contatnment, Boiling Water Reactor (BWR).
Corrmonwealth Edison* has submttted an
. a,pplication for a license amendment, dated September 2, 1976, seektng authorization for Dresden 2 to operate wtth less. than all* loops tn *servtce,
. The staff is reviewing the analyses submitted with the request,* Author!'
ization may be granted once the staff concludes that the an~lvses are acceptable *. Until. that time, Technical Specification 3,6,H.3 p~rmits operation. for on.ly 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with. less. than all loops in servtce~
I II
- ~
. *...1* _....
i:
We find. that this, restriction in lieu. of approved analytical support.
- for ~;.1'*1oop oper~tion is c~nsistent with our criteria~ Based on.this;
.. we*.conciude that *Topic IV~I-A :is: compl~ted a~d acce.ptably resolved for Dresden Statfon Unit 2~