ML19331A936
| ML19331A936 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 04/27/1971 |
| From: | Seaborg G US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Pastore J CONGRESS (JOINT & ROTATING COMMITTEES, ETC.) |
| Shared Package | |
| ML19331A932 | List: |
| References | |
| NUDOCS 8007240526 | |
| Download: ML19331A936 (2) | |
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l lionorabic John O. Pastore, Chairnen f
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Dear Scuntor Pastore:
An you knou, the najor objective of the AEC'n reguir. tory progran is to the public health cud safety by providing rennoaable annurr.nce protect that licenced nuc! car facilitier ara designed, coactructed end operated to prevent accidents from cccurring rad to ultigate their cons:-
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quenccc if thay should occur.
Our cafety revice in based on the it.gortcat principle of 'd:fonce-in-dep th.
All strecturen, systen c, cad compoacats inportrat to scfety nust be designed co that the probability of ca cecident
- occurring is very snall.
We require applicants cud licensees to have and to apply effcetivo que.lity accurance progran's to nscure that nucicat-pouc t-plcutn are denigned, built, cnd operated in n nanner rhich is cannistent with this objective.
Although cnperience uith operating ple.nts hen encouraged confidence in thin prinary line of defensa, sona probicnc haye been encountered during conctruction, pre-op2 rational tactin,c, and early operation *.:hich indiente the need for a usrc rigorcun}cffort in this c rea.
Further quclity c.ssurrnce of forts" are being cpplied td, reduce the 11!wli-load of cubsidiary lines of defence being creded to protect public health t.nd ratety.
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viththedefensc-in-depthc$ncept, the count rvative accurgien In accordanc is neverth21c:.s nede for design purposes that. improbabic cceidents could Engineered safety fcctures are provided to uitigcte tha ccaccquences occur.
. of thane postulated necidents.
The design of cuginacred cafetj features is revicuad to provide ccaursace that they ulll fraction properly under cccident conditionc.
Uc belicyc that these string:nt decip,a requirancats
--~ r.rc r.ppropriate even though the probability of-such accidents occurring is very small cad even though there is a high degree of reduadcucy in
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Each line of d2 fence nuct be revievnd carefully engfucered safaty cyctens.
"~~if the defense-in-depth concept is' to bc ef fectively inglen2nted.
L0nc.of _the enginccred ccfety featurec-provided.on curre'at nuclear pouer l']cate to nitigate the consequences of postulated lonn-of-coolant accidents is redondent enargency core ecoling systens (ECCS).
The une of rcccatly developed, inproved techniques for cciculcting fue,l cladding tecperaturen THIS DOCUMENT CONTAINS POOR QUALITY PAGES 8007240
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follouing postulated loss-of-ccolant cecidents, cud the results of recent preliminary safety research c;:periments have ind'.cated that the predicted raargins in ECCS perfor;'.ance nay not b2 cs large as thone predicted previously.
A centor task force, established earlict-this year by the' Director of Regulation to prov.ide overall canaccr: cat revicu of inportent safety issues, is conducting an c:: tensive evaluation of all the inforaation.ca ECCS pir-forcance with input from reactor manufacturers cad /IC laborator'ics. 'The tack force is revicuing the stcte of prescat kno dedge regt.rding ECCS i
effectiveness for current plan?. designs and is considering uhnt additiont.1 infore: tion is needed and uhat.hcr other short-rrac.c cnd long-tcrn steps should be ta'cca to assure the adequacy of ECCS perfr,:acnce, pending coa-jeletion of this,revieu, un anticipate that there vi]1 he delt.ys 'n t.he licensing of cono plant.s nou under connideration.
17e vould be p] car.cd to discuns thin subjcet in further detail uith the,
.loint Co. lit t ce at its convenience.
Cordially, l
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