ML20213E174
| ML20213E174 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 06/01/1982 |
| From: | Ridgely J Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| CON-WNP-0521, CON-WNP-521 NUDOCS 8206100125 | |
| Download: ML20213E174 (1) | |
Text
{{#Wiki_filter:DISTRIBUTXON: Docket File e. Q[M, N. JUN 1 1~a7 ~ASB R/F s JRidgely ~~ '.y' d ASB Members gr y\\,'g,. Docket No. 50-397 2/ -{ x.o p n ,,,.p ffEMORANDU:1 FOR: ASB Files Cl <q. p.)%.k 'l sp. FROM: J. Ridgely, Auxiliary Systems Branch, DSI 4* /W{i ./ 4
SUBJECT:
TORNADO 11ISSILE PROTECTION FOR WASHINGTON NUCLEAR PROJECT NO. 2 As part of the author's site visit on April 26 and 27,1982, a tour of the plant's missile protection was made. A subsequent review of the general arrangement drawings was made to further assure that all safety-related equipment was missile protected. This review indicated that all safety-related equipment and piping are provided with the tornado missile protection with the following exceptions. 1. The ultimate heat sink consists of two spray ponds with their associated spray trees. The spray trees are not tornado missile protected. Should the spray trees be lost due to tornado missiles, the following procedure would be used. One hundred percent makeup from the tornado / tornado missile protected makeup system would be provided to one of the ponds. From tnis pond the water would be drawn by the standby service water system to cool the plant. The heated water would be returned to the second spray pond to overflow the notch weir and return to the Columbia River via natural ground contours. Either pond can be used as the cooling water supply with the other as the return to the river. He find this approach acceptable. 2. The diesel generator exhausts are not protected from tornado missiles. In particular, the exhausts are susceptible to the utility pole as a l tornado missile due to some high ground within the 0.5 mile specified in l NUREG-0800, Standard. Review Plan, Section 3.5.1.4. ilost of this higher ground is blocked by the cooling towers; however, there is a straight path and a 7.5 degree path for the postulated missile to travel and damage all of the diesel exhausts. The applicant has submitted a probabilistic re-sponse to our question which will be resolved after resolution of the generic tornado missile probabilistic issue or by the applicant providing missile protection. The applicant has estimated the cost of the missile protection at $300,000 ($125,000 for material, $175,000 for seismic re-analysis of the building) plus any costs to relocate hangers within the building. I ~ y}} 8206100125 820601 j J. Ridgely %JhM00 Auxiliary Systems Branch, DSI ee-n pare R. Lobe l 86SI:ASB OFFCCE ) SURNAME) ....h.9..k... ............................ l /82 / om> p ronu ais oo.ao) nacu mo OFFICIAL RECORD COPY um msm-wo}}