ML20126J706

Responds to 810312 Request for Response to Encl ACRS Re Proposed Deletion of Encl Bldg for Containment.Util Since Committed to Tighter Containment Leak Rate Limit. Environ Benefits Now Outweigh Increased Exposure Costs

ML20126J706
Person / Time
Site:	Vogtle
Issue date:	04/29/1981
From:	Tedesco R Office of Nuclear Reactor Regulation
To:	Fraley R Advisory Committee on Reactor Safeguards
Shared Package
ML20126J710	List: ML20126J706 ML20126J712
References
NUDOCS 8105040583
Download: ML20126J706 (2)

Text

..

'yLd %

- . t /p 7 7.~

APR 2 9199; pk ( b' '

Docket Hos. 50-4P4 h gh,2fl98W h.

and 50-4a gpunaan ?

y, commM MEMORANDUM FOR: Raymond F. Fraley, Executive Director 'uh N s

Advisory Conmittee on Reactor Safeguards FROM: Robert L. Tedesco, Assistant Director for Licensing Divison of Licensing

SUBJECT:

DELETION OF ENCLOSURE BUILDING ON A. W. V0GTLE NUCLEAR PLANT, HNITS NOS. 1 AND 2 i

References:

(1) Letter from W. Kerr to A. Igne dated February 18, 1981 (2) Letter fron D. Eisenhut to W. Ehrensperger dated December 1, 1980 On March 12, 1981, lir. A. Igne of your staf f called the Project Manager for the Vogtle Nuclear Plant and requested we provide a response to a letter he had received from Dr. Kerr (Reference ,1) which raised two questions about the posi-tions taken by the staff in our letter to Georgia Power Company (GPC) concerning the proposed deletion of the enclosure building for the containr.:ent on the A. W.

Vogtle Nuclaer Plant (Reference 2). References 1 and 2 are enclosed for esse of reference.

The NRC staff did not, at the time that the Reference 1 letter was written, assign a quantitative value to the apparent change in safety margin (Dr. Kerr uses the tern " risk"). What was known at that time was that the CP holder was proposing to eliminate a major structural design feature (the containment enclosure bui.1 ding) and its safety grade exhaust and recirulation systeu, both of which had been described in the CP applications reviewed by the staff, with nc compensating improvements in the design of the containment itself. With no other consider-ations, this could have resulted on a relative basis, in almost doubling boundary and tripling the thyroid 1.0CA dose at the low population zone boundary. Since our letter, Reference 1 was written, the CP holder has committed to a tighter containment leak rate limit than assumed in the CP review (0.2%/ day vs 0.3%/ day).

He also plans to take credit, based on Post CP data, for better site neteorology than was assumed in the CP review. We have subsequently completed preliminary calculations and agree that these two factors will offset the potential dose increase that would otherwise result from eliminating these design features.

B1050405gs O o=> ....... .. ....... ... ................ ..... .... ...... .. . . .. .......... . . ... .. ... . .. ...... .............. ....... .. .....

l""> ............. ..... ..................... ........ ... ........ .. . .... ...... ... .. .. .......... .. . .... .... ......... .......... .......

me ronw ain iioisui sscu e24o OFFICIAL RECORD COPY ' " 'n w a2 m

.z .-

3.  !

- q, 4 t, .g ., -f 5 y

I Rayrond F. Fraley

.l i

I The need.for a cost-benefit analysis cones from 10 CFR 51 - Licensing and Peculatory Policy and Procedures for Environmental Protection, specifically  ;

section 10 CFR 51.20(b). The initially perceived cost (environmental effect) l was increased radiation exposures to the public. This would be weighed against i whatever benefits obtained from eliminating these design feature:, (a.g. reduced cost, construction time, etc.). Since it now appears that there will be no l increase in environnental effect above that considered at the CP stage, it is  ;

clear that the benefits will outweigh costs, environmentally speaking. j original signed by i

Robert L. Tedesco, Assistant Director i for Licensing  ;

Division of Licensing  !

1 Attachment. .

References 1 and 2 l DISTRIBUTION -

bec: . [

. Docket or Central File ACRS- (16)  :

NRC PDR~ NSIC Local PDR ~

TEPA  ;

LB #2 TIC ,

DEisenhut  ;

RPurple .l RTedesco .};

ASchwencer Licensing Project Manager i Licensing Assistant l I&E(3) {

I a

1 ~

L 2-

,,,,c, y .g.(yg LB# A/D f g .g..........{3....... ......... .. ..... .. ....... ......... .. .... ...... ... . .................... . .... .... .......

~]

ewusaur) . .S. . . u. .r.w. .e...A5 RLTe c l.chwep..c'e

.l..........

. . . . .......r .......... .......... ... , ....... ..... .. ................. ..... ............ . ....... ........

can) .... 4// /81 4/ 81 4/

..../.g. 81 uc roem :ne no comen u4o

. OFFICIAL RECORD COF#Y _ . . _ _ . . 9=M*t?.H