ML19322B609

Responds to NRC 751015 Ltr.Discusses Review of Design Basis for Reactor Vessel Support Sys & Concludes That Further Analysis Not Required to Assure Public Health & Safety. Forwards Model Used to Calculate Support Sys Loads

ML19322B609
Person / Time
Site:	Oconee
Issue date:	11/14/1975
From:	Parker W DUKE POWER CO.
To:	Rusche B Office of Nuclear Reactor Regulation
Shared Package
ML19322B610	List: ML19322B609 ML19322B612
References
NUDOCS 7912040636
Download: ML19322B609 (1)

Text

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November 14, 1975 LATORY DOCKET FlLE COPY

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Mr. Benard C. Rusche Director of Nuclear Reactor Regulation [[ '

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Washington, D. C. 20555 c ' ' g ,,,/+g -/ Attention: Mr. R. A. Purple, Chief Operating Reactors Branch #1 g$ h.  ! Re: Oconee Nuclear Station Docket Nos. 50-269, -270, -287

Dear Mr. Rusche:

In response to Mr. R. A. Purple's letter dated October 15, 1975, a review of the design basis for the Oconee Nuclear Station reactor vessel support system has been conducted. The model used to calculate the reactor vessel I support system loads resulting from a loss-of-coolant-accident is attached. l These loads were then combined with normal operating loads and seismic loads to determine the resulting total stresses on the reactor vessel support system. As noted in the attachment, blowdown jet forces at the location of the break were considered in the design of the reactor vessel support system. Transient differential pressures in the annular region between the vessel and the shield j wall and transient differential pr*.:ssures across the core barrel within the j reactor vessel, were not considered. 1 The method of analysis described above conformed to requirements existing at the time of the Oconee design. Based on this fact, consideration of the design conservatism which exists in the reactor vessel support system and the low probability of the particular pipe rupture which could lead to additional transient loads, it is our conclusion that further analysis is not required to assure the health and safety of the public. Very truly yours,  ; 9 L u6.Puk-) William O. Parker, Jr. ]yg e

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