ML19329B318
| ML19329B318 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 10/05/1976 |
| From: | Vollmer R Office of Nuclear Reactor Regulation |
| To: | Vassallo D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19329B319 | List: |
| References | |
| NUDOCS 8002040751 | |
| Download: ML19329B318 (2) | |
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OCT 5 376 D
Docket No. 50-346 PEMiPACi]M F#A:
D. 3. Vassallo, 8ssistant Director for Li+t !!ater Peectors, OP84 FROM:
P.ichard 'i. Voll er, Assistant Director for Site A"3 lysis, DSE ithiECT:
REVISG A?2 IHP!!T ON TURSINE ?ilSSILES TO DAv!S-9 ESSE 991T H0. 1 SER PLAMT 4A"E: 0.viis-Besse Unit No.1 LICENSING STAGE: OL OCCXET 'Jt."lE?:
50-346 "ILESTONE NL'MER: U//-
s LW..u. 1 ; L. En cl e, L P!M RESPONSIBLE DON'CH:
c REctCSTEC COPPLETIO!! DATE: :!/A REVI:u STATijS:
,W inent corelete Attached is the Accicent Analysis Cranch revised SE't input an turbine nissilas.
Our review indicates that a portion of the raactor contain%2nt building is vulnerable to destructive overspeed turbine missiles.
lasec on inforNtion presently availaole to the staff, our best estimate values, as a result cf a turoine failure at Davis Besse 1 is 1.a x 566.-b)9, is tnt the probability of consecuerces in excess of 10 cy9 17,n ecs,,.po This estimate was ave in the absence of (1) a cetailed analysis ni ea r.
{hepr0]2bilityofpenetrati90theexSosedareaofthecontain~ent35i,1n W11 an prinry containrent wall (assimi to te unity in our acti"a+)') cdsn and (2) e etailtd an31ysis of the orecability that 3 falline -issilo >cyl a
b"e in primary syste' nining nr ccToenr:nts (assured b *se n57 1-cu e sti"'a te ). The value of 1.4 x 10-6 per y ar is consicerahlb Ater *%e cur current icceptance criteria; '<? co not telieve tnt a (etatibd a. [1 Ni '
a or the two treas in'!icated aheve wcul causn tha nrocabili t" e3+.inata
.n be revisen da<n-rard suf ficiently to met our current accentbnce crf'*ri
.n cue view the turbine missile-related risks can be shmn to ha ef Nifb+1y 10ver tnan our cresMt estimate cnly if the cratincs atova theSreevri r
a'ut stear cener3ters ire desien'd to sustain the i:-sct of a free _f 511th nissile. This, if necessary, cculd he accc nlished threu r s*ructural up gradinc.
These fincines are substantially different than tcr.se reached at the CP s ace, due ::rincireally to 3 revised report by M relatine to the probability of cen-tairrent senetration (at the C
stare the C' renort sunported a cenclusion that. cenetration wculd not occur, the opsocite conclusion results fron the,
latest GE recort).
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ante >
Fesus AEC 318 (Rev. b53) AECM 0240 W u. s. eovannesent Feintsme oprics sete.sse.see 8 0 02 0 4095l
a t'
- OCT 5 37S In view of the already low nrocability of the event, and the similarity of this cesign to oceratino units with resoect to turbine nissile risks, we believe that any further action on Davis 9 esse 1 can be best accccclished as a backfit, at such time as an overall policy on turoine iissile risks is established.
A revised SER inpu} on this subject is attached.
This review was cecrdinated by Charle* errell, Site Analyst, Section 9, 4ccident.inalysis 3 ranch.
1 kichard 4. Vollmr,.tssistant 9f rector for Site tnslysis nivision of Sica Safoty and Enhviron ent31 Analysis Ecclosure:
AAB revised SER input for Divis Besse Unit No.1 Distribution S. Hanauer C. Ferrell H. Denton R. Boyd D. Muller J. Stolz F. Miraglia L. Engle J. Miller Docket Files L. Crocker NRR Reading R. Vollmer DSE Reading W. Mcdonald (w/o encl.)
AAB Reading J. Panzarella (w/o encl.)
AAB File P. Shuttleworth D. Bunch L.-Soffer D
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_]SId26 10/5/76 Poses ABC 318 (Rev, ble) ABCM 0240 1lr u. s. novs==mear enmrime arrican seve.sae.e e