ML25196A363
| ML25196A363 | |
| Person / Time | |
|---|---|
| Issue date: | 03/12/1976 |
| From: | Moeller D Advisory Committee on Reactor Safeguards |
| To: | Anders W NRC/Chairman |
| References | |
| Download: ML25196A363 (1) | |
Text
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 March 12, 1976 l:k>norable William A. Anders Chairman Nuclear Regulatory Commission washington, DC 20555 SUBJOC'l':
REPORI' 00 COOTAINMENT SYSTEM K>DIFICATIOOS, VERMJNT YANKEE NOCLF.AR POOER STATIOO'
Dear Mr. Anders:
During its 191st meeting, Yarch 4-6, 1976, the Advisory Colllnittee on Reactor safeguards met with representatives of the Vermont Yankee Elec-tric Company, the Mark-I O;,mers Group, the General Electric Company, the Bechtel R>wer Corporation, Teledyne Materials Research Corporation, the Nutech Corporation, and the Nuclear Regulatory Commission Staff to discuss the modifications in the containment system for the Vermont Yankee Nuclear R>wer Station. A SUbcornmittee of the ACRS and its consultants also considered these modifications at a meeting on March 3, 1976. ouring its review, the Conmittee had the benefit of the documents listed. '!he Conmittee also heard oral conments by Mr. David M. Scott, Department of Health, State of Vermont.
'lbe modifications consist first, of an increase in the drywell pressure of 1.25 psi and a reduction in the wetwell, or torus, pressure of 0.45 psi, and second, of the installation of a tie-down system for the torus. '!he Conmittee was informed that the tie-down system will be completed in the near future, and also that the water volume in the torus, the torus pres-sure, and the drywell pressure will be closely monitored.
'Ihe Conmittee concurs in the view that these modifications represent an improvement in the safety margin for the Vermont Yankee Nuclear R>wer Station containment pe:r:formance capability. '!he modifications were based on the Short-Term Program which consisted of small scale tests and analytical studies. '!'he Mark-I O;,mers Group also informed the Com-mittee of its r.ong-Term Program to perform large scale tests which will also include three-dimensional effects. 'Ihe Committee believes that the I.ong-Term Program will lead to significant findings and recamnends that this program proceed in an expeditious manner.
'Ihe Cor.nnittee wishes to*
be kept informed.
1776
Honorable William A..Anders March 12, 1976
'!he Advisory Committee on Reactor Safeguards wishes to point out that there are several generic items of importance for boiling water reactors, and the resolution of these items will, of necessity, be relevant to the Vermont Yankee Nuclear Fower Station.
Sincerely yours, BcJ..e_ v. o/J1 ~
REFERENCES:
Dade w. M>eller Chairman
- 1. Mark I Containment Evaluation Short-Term Program - Final Report; volumes r-v, dated September 1975.
- 2. Vermont Yankee Nuclear Fower Corporation letter, dated February 6, 1976, transmitting an evaluation of torus behavior.
- 3. Order for ftk>dif ication of License for Vermont Yankee Fower Corporation, dated February 13, 1976.
- 4. Safety Evaluation Report, dated February 13, 1976.
- s. Testimony of Mr. David M. SCott before the Mvisory Conmittee on Reactor Safeguards, Nuclear Regulatory Commission, March 5, 1976.
1777