ML20214G635

Requests Info Re Consequences of Postulated Failure of Steam or Feedwater Lines.Any Design Mods Should Include Appropriate Consideration of Encl Guidelines/General Request for Info.W/O Encl

ML20214G635
Person / Time
Site:	Columbia
Issue date:	12/22/1972
From:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
To:	Stein J WASHINGTON PUBLIC POWER SUPPLY SYSTEM
References
CON-WNP-0068, CON-WNP-68 NUDOCS 8605220342
Download: ML20214G635 (2)

Text

- _ .- - . . . . . . - . . . - - . .. .- - _

. ~ . - -

, ENCLOSURE 1 i (

.,[:k, UNITED STATES }

!/ D: II-ATOM!C ENERGY COMMISS!ON

[f$hj'l we,ssi.scros o.c. :om

% '. .%. a >

Docket lio. 50-397 .,

- DEc 2 21371 . - .$ .

-1 ..

L!ashington Public Power Supply Systea ATTis: Mr. J. J. Stein .

'~

~".

~~

1 Managing Director ~ ~

301 Fifth Avenue, P. O. Box 958 Richland, !!ashington 99352 C..

Gentlemen:

The Regulatory staff's continuing review of reactor power plant' safety J.

indicates that the ccnsequences of postulated pipe failures outside of the containment structure, including the rupture of a main steam or 4 feedwater line, need to be adequately analyzed and documented by licinsees and applicants, and evaluated by the staff as 'soca as possible.

Criterion tio. 4 of the C'raission's General Design Criteria, listed in ,

4 Appendix A of 10 CFR Part 50 requires that:

" Structures, systems, and components important to safety shall be designed to acco=odate the effedts of and to be co.npatible with the environmental conditions associated with normal operation, i

maintenance, testing cr.d postuhted accidents, including loss-of-coolant accideats. These structures, systecs, and components shall be appropriately protected against dynamic effects, including the effects of missiles, pipe wi.ipping, and discharging fluids, ti.at my result fro., equipment failures and froa events and conditions outside the nuclear power unit." ,

Criteria Nos. 40 and 42 of the pravicus (1957) issue of the Cor:nission's'

• General Design Criteria reflected siaiiar requirements.

4 Thus,. a nuclear plant shpuld be designed so that the reactor can be shut-dowa and maintained in a safe shutdo m condition in the event of 'a postulated rupture, outside containaent, of a pipe ccataining a high energy fluid, including the double ended rupture of the largest pipe in main steam and feeirater systa.is. Plant structures, systex.s, and compa-r.ents important to safety should be dcsigned and located in the facility to accommodate the effects of such a postulated pipe failure to the c:: tent necessary to assure that a safe shutdoun condition of the reactor .

can be accomplished and maintained.

8605220342 721222 PDR ADOCK 05000397 A PDR ,.

[ (-

Washington Public Power Supply System -2.

Based on the information we presently have available to us on the Hanford No. 2 Nuclear Power Plant, we understand that the cain steam tunnel enclo::es all four steam lines and that the steam lines are being designed to meet seismic Category I criteria. The feedwater lines are also routed through the steam tunnel. Overpressurization of the steam tunnel is prevented by venting the tunnel to the turbine building. The diesel generators are located in a Class I structure which is on the opposite side of the reactor building from the steam and feedwater lines. The control room is remote from the main steam lines and feedvlater lines and is separated from the turbine building by a concrete wall. From this it appears that safe shutdown of the plant would not be prevented by the postulated failure of the steam or feedwater lines. .

However, to assure a thorough review of the consequences of the postulated accident, we request that you provide us with an analysis and other relevant information pertaining to the accident consequences and protection provided using guidance in the enclosed general infor-pation request. The enclosure represents our basic information re-quirements for plants now being constructed or operating. You should determine the applicabilityg for the Hanford No. 2 N; clear Power Plant, of the items listed in the enclosure.

He will need, as soon as possible, an amendment uith your analysis of this postulated accident situation for the Hanford No. 2 facility. If the results of your analyses indicate that chsnges in the design of structures, systems, or components are necessary to assure safe reactor shutdown in the event this postulated accident situation should occur, please provide information on the revised design of your facility to accommodate the postulated failures described above. Any design cod-ifications proposed should include appropriate consideration of the guidelines and requests for infor.ution in the enclosure. Within 14 days after receipt of this letter, please inform us when we may expect to receive your amendment. Sixty copies of the amendment shculd be provided. ,

A co'py of the CocT.ission's press announcement on this matter is also enclosed for your inforcation.

Sincerely, d Q A. Giambuss'o, Deputy Director for Reactor Projects Directorate of Licensing

Enclosures:

As stated ,

cc: See attached O