ML20037B567
| ML20037B567 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 03/31/1958 |
| From: | Price H US ATOMIC ENERGY COMMISSION (AEC) |
| To: | |
| Shared Package | |
| ML20037B566 | List: |
| References | |
| NUDOCS 8010170756 | |
| Download: ML20037B567 (3) | |
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?yhhh1 UNITED STATES ATOMIC ENERGY COMMISSION I#
' >f,'%)f WASHINGTON 25. D. C.
O hnN o AMENDMET NO.1 10 CONSTRICTIOGERHIT NO. CPPR-2 IssusD TO COMMONPlLTH EDISON COMPANY DOCKET 50-10 t
t Amendment No. 1 Co=enuealth Edison Company on June lh,1957, filed a report entitled " Enclosure Section" describing the final design of the containment building for the proposed fac W ty which was licensed for ecnstruction by the Commission in Construct, ion Ferr.it No. CPPR-2, dated May h, 1956. On November 6,1957, the company fil:d Addendun No.1 to the above-described report, the addendu. being designated as "Ccatrol of Negative Pressure Within the Dresden Enclosure".
En. sed upon review of the information contained in the application and amendments thereto subnitted to date, and the report of the Advisory Comittee on Reactor Safeguards dated November h,1957, the Comission finds that:
1.
If the containnent building is constructed as designed, it will withstand an internal pressure of 37 psig. The con-tainment building is designed in accordance with Section VIII of the ASME Boiler and Pressure Vessel Code for an internal pressure rise of 29.5 psig and will be tested pneunatically at 37 psig.
2.
If the containnent building is constructed as designed, it appears that the building will have a leakage rate not in excess of 0.5% per day at 37 psig.
3.
The maximin credible accident for the proposed reactor as presently designed and its consequences for the safety of plut perscnnel and the surrounding pop. dace have not yet been definitively established. This cannot be dons until the find design of the facility is conplete and the characteristics of the core determined.
h.
The applicant has postulated an accident, referred to as the " worst reasonable" accident. This accident is postulated to result fron the instantaneous release and partial flashing to stean of the pressurised hot water contained in the reactor and primary recirculation loop at rated full power operation, a nuclear excursion rufficient to nelt all of the uranium oxide in the ccre, and a cher.ical reaction between water in the reactor n::sel and 254 of the circenium in tha fuel elenent cladding.
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- 5. Tne pressure rise within the c:ntainer frca2 the accident postulated shedd not exceed 35 psig. The artillary cooling means proposed by the applicint is espable cf reducing the inta:s.1 pressure from 37 peig to 6 psig in one day after the cocident.
6.
In calculcting the radiatien denges resulting frsa the accident postulated; the tpplicant assumed that 30% cf the solid and 100%
of the gaser.u fisaien predacts b.ilt up during a 365-day reactor cperating period are released and :niferr.ly dispersed within the container. Based en a leskars rate of OdT pe: day for an initial post-accident pressre rate cf 37 psig, v.tich decreased to 6 psig in ene day, the exterral d:ca to terrers standing fer an eight f
hour peri:d under the center line cf the energing cirmd at a distance of one hs1f mile frcs the sphnre u.e conditions of severe tenpersture inversion venld be approximately 65 rea.
In additiens the direct gu.na radistitn to rut.h a persen j
would be approximately h rea. The clonst Itad area cut-side cf the applicant's centrol is crs-h21f r.ile frem the rea: tor.
7.
The obsernble radic.tien expecure effe:te t: be anticipated frco the doses which wydd result frem t}n ' vest reasonablen accident portuiste:i by the applicant muld be scns inju y to the thyrcid tr th decease in thyrcid f.:ncticn in a small percentage of any adults expcaed for an eight her period at the site boundary. There migir, be s:me risks cf eub-sequent derelcpsent cf cancer of the thy.20id in the case of any children expeced fer e.t eight hc= peried at the site boundary.
i S.
We do not believe that the neuiv.m credible ac ident as finally postulated will han cme?ms: c.s grest as the "weret retsonable" acciden^ postulated by the applicant. As stated in Finding N:. 3 akw, this, of course, cannet be finally establiekd un^.11 the final design cf ehe facility is c:mplete and the chracte-istics of the cem determined.
9.
1he consequences of the t rest r -ascesbie a ?ident postulated by the applicant tre yrd.4.bly n:t calible.
Son + cf the hut reletsed fr:m rnh an a::idern wdd be t er.sferred to surcunding s nid msteri 0. ad wnd de:recse the r.agsituds cf the press':re rise. Tether, it is pretatly net credible the-the enbi e cue v:;uld melt de %
Pether, it is highly m:likely Wat 25.T c.f the circeniim would ret:t w'.th water. In addition, emergency procedures should preved smy persea frcn being continuetsly exposed at the site boundry for eight hors. Thus, the conseqmnces of the caximum credible a::ident shydd ba c:nri.d:sbly isss than ihrse pcstul ued by the r.ppi;nr/
"n iha t re:
r,ucmtlC a::ident fcc exp:rc Cc.t thi ne r e t l'ad a en at the site bemisries.
1-F
- 10. Operating experience with the Experdrental Boiling Water Reactor at Argenne National Laboratory and the Boiling Water Reabtcr at Vallecites, California dr.dicates that a reacter of the general concept propcsed can be operated with a high degree of inherent stability.
On the basis of these findings, the Comission concludes that the contairment building as desigmd is adequate to provide the necessary protecticn to the health cad safety of the public from any reacter accident which presently appars credible.
p Pased on the above findings and conclusion, the Ocmissior. hereby amends Constructicn Femit No. CPPR-2 to add the fellowing new paragraph after condition (6) in the pemit:
nThe Ocmission approves the followdag technical specifications:
(1) The containnent vessel as described ir. the appliccticn,
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as cended, subject to c final detemination by the Con-missicn of the effects of the maximun credible accident based upon consideration of the final Hazard Su::r.ary Reporta.
FOR THE ATOMIC DERGY COWlSSION H. L. Price Directcr Division of Licensing and Regulatien Date: MAR 3 2 geg l