ML20127P349

Discusses ACRS 150th Meeting on 721012-14 Re Conversion of License for Plant to Full Term OL

ML20127P349
Person / Time
Site:	Monticello
Issue date:	10/19/1972
From:	Siess C Advisory Committee on Reactor Safeguards
To:	Schlesinger J US ATOMIC ENERGY COMMISSION (AEC)
References
NUDOCS 9212020197
Download: ML20127P349 (4)

Text

. . . . . ,

m ,_ . .

} 'i , ,

ADVISCRY COMMITTEE ON RE/sCTOR SAFEGUARCS UNITED STATES ATOMIC ENCRGY COMMISSIOld WASHINGTON. D C. 2054 N

October 19, 1972 r

Ilonorable James R. Schlesinger '

Chairman U. S. Atomic Energy Comission ,

Washington, D. C. 20545

Subject:

REPORT ON MONTICELLO NUCLEAR GENERATING PLANT, UNIT NO._1

Dear Dr. Schlesinger:

At its 150th meeting October 12-14, 1972, the Advisory Committee on Reactor Safeguards reviewed the application by the Morthern States Power Company-for conversion of its provisional operating license for the Monticello Nucicar Generating Plant, Unit No. 1 to a_ full-term operating license. This project was considered-at Subcommittee tucetings on Septe r.ber 11 and 30,1972, in Washington, D. C. :During its review, the Committee had the benefit of discussion with rep-resentatives and consultants of the Northern States Power Company, the General E1cetric Company, and the AEC Regulatory Staff, and of the documents listed. The Committee has reported to the commission the results of its review of various aspects of this project in reports dated May 11, 1966, April 13, 1967, January 10, 1970, and June 15, 1970. .

In its report of January 10, 1970, on the application for a provisional l operating license, the Co:mittee stated that the applicant had been L responsive to recommendations made in the Committee's construction-li- permit report, but made further specific recommendations relating to

[ main stean line valves, vibration testing,.and integrity and isolability je- of instrument lines. Operating experience suggests that continuing 6 study _and surveillance is necessary to assure, satisfactory performance j of the main steam line isolation valves. The vibration testing program ij during the preoperational period was satisfactory. The' Comittee

y. -believes,the applicant should further evaluate the design of the instrument y lines with respect to.the Supplement to safety Guide 11; the Committec-p vishes to be kept informed. ,,

F rs 4;

(:

L

-- 9212020197 721019 Je499a -

PDR ADOCK 05000263 i.

t+ '.-

O PDR Ve

- . . . - .e , ,

,......,,+n,,,4..

{ '

lionorable Jaraes R. Schicsingc r , October 19, 1972 The Com.nittee also called attention to the need for continuing evaluation and appropriate action with respect to problems conmon to rater-cooled reactors. One of the itens mentiored uns the problem of hydrogen generation in the unlikely event of a loss-of-coolant accident. The applicant has described his studies for controlling hydrogen buildup, but has not submitted a firm proposal. The Committee belf aves the applicant should commit himself to completion of design and installation of an acceptabic system on a time schedule satisfactory to the Regulatory Staff.

Another item specifically rentioned was the need for design features to make tolcrabic the consequences of failure to scram during anticipated transients. Studies by the reactor designer indicate that a system modification may accomplish the desired objective, but a final determination has not yet been inade. The applicant has indicated that he vill make the necessary modifications when a decision has been made on a generic ,

basis.

Analyses of postulated control-rod drop accidents have been revised by the applicant to employ a more realistic rate of reactivity insertion than formerly assumed. These analysca indicate that, for accidents occurring during certain operations and certain portions of the fuel cycle, the results may be ur.acceptabic. The applicant has proposed interim procedures which the Com.ittee believes to be sa*.isfactory. The final resolution should be made in a manner satisfactory to the Regulatory Staff.

Commercial operation of the plant started June 30, 1971. There have since been a number of unscheduled shutdowns. caused by equipment- or system -

malfunctions. The Committee recogni::es that, during the early stages of operation of a large power plant, some forced shutdowns will occur and corrective action will be necessary. The Coumittee believes that the number of such events in the Monticello plant has not been excessive.

Ilowever,'the Committee wishes to reiterate its opinion that improvement of the plant and operating procedures to enchance safety should be a continuing process, factoring in technological advances and past and future industry-wide experience.

The Committee believes that the applicant should seek a careful and detailed delineation of responsibilities and authority for determining action Icvels, implemen*ation, and coordination of the State and local agencies involved in emergency plans. -

9 I

e

_ ~

~4 ,

lionorabic James R. Schicsinger 3 October 19, 1972 Other problems relating to large unter reactors which have been identified by the Regulatory Stafi and the ACRS and cited in previous ACRS reports,

,, should be dealt with appropriately by the Regulatory.Staf f and the applicant as suitabic approaches are developed.

The Advisory Committee cc Reactor Safeguards believes that, in vicw of. ,

the operating experience to date, and if due regard is given to the items mentioned above, there is reasonabic assurance that Monticello Nucicar Cencrating Plant, Unit No. 1, can continue to operate at power levels up to 1670 !c1(t) under a full-term operating license without unduo rich to the health cnd safety of the public.

Mr.11111 did not participate in the review of this project.

Sincerely 12nI8e ,

Original Signed by C. P. Siess C. P. Siess Chairman References Attached.

d O

9 e7 4 a= 9 g

i

.s

- - J -

3 lionorable James L. Schlesinger October 19, 1972 e.

Referenets 1 Final Safety Analysis Report for Monticello Nuclear Generating Plant.

, Unit No. I 1 2. Amendments No. 10-24, 26 and 27 to the license application

3. Northern States Power Company Iceter dated February 28, 1072 transmitting Six-Month Operating Report No. 2 for the period of July 1 to December 31, 1971 ,

4. Northern States Power Company letter dated June 15, 1972 transmitting an Application to convert Provisional Operating License No. DPR-22 to a Full-Tern Operating License for the Monticello Nuc1 car Generating Plant, Unit No. 1

5. Northern States Power Company 1ctter dated August 30, 1972 transmitting Monticello Nucicar Generating Plant Six-Month Operating Report No. 3 for the period of January 1, 1972 through June 30, 1972 l

I

.==**#

-,yv

. - .. --