ML17037B785

Letter Enclosing a Copy of the AEC Regulatory Staffs Letter to the Applicant Which Requests Certain Actions to Be Taken Regarding the Drywell Vacuum Breakers

ML17037B785
Person / Time
Site:	Nine Mile Point
Issue date:	01/24/1973
From:	Bordenick B US Atomic Energy Commission (AEC)
To:	US Atomic Energy Commission (AEC)
References
Download: ML17037B785 (13)

Text

Di'stribution:

OGC Files Bor.deni chic, Massar Shapar Engelhar dt REG Central PDR LPDR January 24, 1973 Chairman, Atomic Safety and Licensing Board Panel U. S ~ Atomic Energy Commission Washington, D. C.

20545 In the Matter of Niagara Mohawk Power Corporation (Nine MQe Point, Unit No. 1)

Docket No. 50-'220

Dear Sir:

Enclosed is a copy of the AEC regulatory sta6's letter to the applicant dated January 12, 1973, which requests certain actions to be taken regarding the dryweQ vacuum breakers, at the Nine Mile Point, Unit No. 1 facility.

Sincerely, Bernard M. Bordenick Counsel for AEC Regulatory Staff

Enclosure:

As stated cc w/enclosure Mr. Z. Bruce MacDonald ArvinE. Upton, Esq.

Secretary of the Commission Chairman, Atomic Safety and Licensing Appeal Board Mr. Frank W., Karas OFFICE D OGC

..Sardenick; 1/24/73 SURNAME >

7I DATE >

Form hKC-318 (Rcv. 9-33) hKCM OZ40

• U..S, GOVERNMENT PRiNTINQOFT@: 1972-466 983

I'

~ Io

~

l!,tr '

r 5f g'i

-;p ('<.,f'),'g pg<<

5 5$

'I 5, /I>. ~

~

I, y

.p )', gy

~ pr 5'"

k,'$

p

.5't

op i 5.>ypr 5

UNITED STATES ATOMIC ENERGY COMMISSION WASHINGTON. O.C.

20545 y4-~O Chairman, Atomic Safety and Lice:nsing Board Panel U. S. Atomic Energy Commission Washington, D, C.

20545 Q CQ~

January 24, 1973 J'iL yy, In the Matter of Niagara Mohawk Power Corporation (Nine Mile Point, Unit No; '1)

Docket No.

50-220

Dear Sir:

Enclosed is a copy of the AEC regulatory staff's letter to the applicant dated January 12, 1973, which: requests certain actions to be taken regarding the drywell vacuum breakers at the Nihe Mile Point, Unit No. 1 facility.

Sincerely, Bernard M. Bordenick Counsel for AEC Regulatory Staff

Enclosure:

As stated cc w/enclosure Mr. J. Bruce MacDonald Arvin E. Upton, Esq.

Secretary of the Commission Chairman, Atomic Safety and Licensing Appeal Board Mr. Frank W. Karas

goos

~t Co rr

~~4ns Cyp4r 0

OI UNITED STATES ATOMIC ENERGY COMMISSION WASHINGTON, D.C.

20545 January 12, 1973 Gentlemen:

Tests of drywell vacuum breakers in some BWR plants have demonstrated that these devices failed to perform properly and did not have accurate valve position indication in the control room.

In addition, technical specifications for operability checks and leakage surveillance have been inadequate to assure that the vacuum breakers will not compromise the function of the suppression pool and willfulfilltheir function as an engineered safety system.

As a result of this experience, it is requested that the following actions regarding the drywell vacuum breakers be taken for your nuclear power station:

Xmmediate Action:

2.

Check the position of. each vacuum breaker by direct visual inspection, if possible, or by position indicators.

\\

Close those vacuum breakers that are open.

If the position cannot be ascertained to be closed, take immediate remedial action to assure closure.

Within 60 da s

rovide the Commission with a re ort that includes:

1.

Information regarding the plant vacuum breakers, including:

a.

Number installed.

b.

Location of the installed vacuum breakers.

c.

Size of each.

January 12, 1973 d.

Design differential pressure to open, the test methods used to verify. opening of the vacuum breakers and the test results.

e.

Manufacturer, model number, ratings, and modifications, if any, of the vacuum breakers and position switches.

f.

Installed assembly drawing, including testing equipment and position switches.

g.

Materials used in the vacuum breaker and position switch, including seals,

seats, bearings, lubricant, body and oper-ating parts.

h ~

Position indicators and alarm locations, design criteria, surveillance requirements, and redundancy of position

switches, circuits, indicators and alarms.

Capability of parts and their design life in the most severe suppression chamber operational transient and accident environ-ments..*Discuss possible deleterious effects of chemicals present during the surface preparation and application of the suppression chamber coating and of nitrogen on vacuum breaker system materials.

Advise what tests have been performed on the vacuum breakers and their position indication system in a simulated accident environment.

2.

For the tests performed on each vacuum breaker system, 'provide a brief description of acceptance criteria and test results, including:

Preoperation and periodic surveillance tests.

b.

Other tests and reasons for the tests.

3.

A description of corrective action taken to remedy any failure of the vacuum breakers or their position indication syst: em, including a discussion of the cause of the failure.

4, A description of the station procedures or checks used to assure that the vacuum breakers:

a.

Function properly prior'o startup.

b.

Are closed after completion of pre-startup functional checks.

c.

'Are maintained properly.

\\

l 4

January 12, 1973 5.

A curve showing total allowable drywell to torus bypass

area, in terms of equivalent orifice area, as a function of various primary system break areas for containment design and test pressures and indicate the fraction of this total bypass area that is allowable for the vacuum breakers.

Show the limiting condition of operation for vacuum breaker bypass area on this graph.

6.

A discussion, based on the information provided in item 5, of the allowable distance in inches the vacuum breaker can be off its seat and the degrees away from the closed position with the pivot point as the apex.

7,

~

8.

The flow vs area characteristics of the vacuum breaker and a

curve showing vacuum breaker bypass area vs degrees the vacuum breaker is open from closed to full open.

An analysis of the capability of the drywell sprays and the suppression chamber sprays to accommodate primary system break

areas, including a curve of break areas vs total bypass area within sprays'apability.

Include a discussion of the avail-ability of sprays, considering interlocks, during a LOCA.

9.

Additional equipment and systems and/or modifications to existing equipment and systems proposed to assure that malfunction of vacuum breakers can be detected reliably and appropriate action can be taken.

10.

Proposed.technical specifications for limiting condition of oper-ation and surveillance requirements with bases regarding the drywell vacuum breakers.

Durin the next refuelin outa e:

Perform the following tests and submit the results to the Commission in the subsequent-semiannual report:

Pressurize the drywell to an appropriate pressure above the suppression chamber pressure and determine the leakage rate to the suppression chamber over a sufficient period of time to assure reliability of leakage

data, compensating for temperature difference.

If the leakage rate exceeds the allowable, as determined in item 5 of the 60-day report, take the appropriate corrective measures and retest until the total leakage rate is acceptable.

~.

January 12, 1973 b.

Test each vacuum breaker to assure that it will open with a specified suppression chamber pressure above drywell pressure to prevent drywell failure due to external pressure.

c.

Check and adjust each vacuum breaker position switch to assure that an alarm in the control room will be actuated at the time or before the vacuum breaker is opened to the amount specified as a limiting condition of operation.

d.

Determine that both the opened and closed positions, within allowable limits, of each vacuum breaker are properly indicated in the control room.

Three signed originals and thirty-seven copies of your submittals are required.

4 ~

Sincerely,

~

r Donald JWSkovholt Assistant Director for Operating Reactors Directorate of Licensing ceo

Docket Nos. 50-237 and 50-249 Commonwealth Edison Company ATTN:

Hr. Byron Lee, Jr.

Assistant to the President Post Office Box 767 Chicago, Illinois 60690 cc)

John W. Rowe, Esquire Isham, Lincoln & Beale Counselors at Law One First National PLaza Chicago, Illinois 60670 Morris Public Library 604 Liberty Street Morris, Illinois 60451 (For Docket Nos. 50-237

& 50-249)

Docket No. 50-133 Pacific Gas and Electric Company ATTN:

Mr. Frederick T. Searls Vice President and General Counsel 77 Beale Street San Francisco, California 94106'ct Philip A. Crane, Jr.

'Pacific Gas and Electric Company 77 Beale Street San Francisco, California 94106 Docket: No'0-220

'iagara Mohawk Power Corporation ATTN:

Mr. Thomas J.

Brosnan Vice President and Chief Engineer 300 Erie Boulevard West

Syracuse, New York 13202 cc.'Arvin E. Upton, Esquire

LeBoeuf, Lamb, Leiby

& MacRae 1821 Jefferson Place, N.

W.

Washington, D.

C.

20036 Oswego City Library 120 East Second Street

Oswego, New York 13126

Docket No. 50-245 The Millstone Point Company ATTN:

Mr. D.

C. Switzer President P. 0.

Box 270 Hartford, Connecticut 06101 cc:

Mr. Anthony E. Wallace, Pres.

The Connecticut Light & Power, Co.

Mr. J.

R. McCormick, Pres.

The Hartford Elec,'Light Co.

Mr." Robert E. Barrett, Jr., Pres.

, Western Massachusetts Elec.

Co.

'Mr. William H. Cuddy Day, Berry

& Howard Waterford Public Library Rope Ferry Road, Route 156

'aterford, Connecticut 06385 Docket No. 50-263 Northern States Power Company ATTN:

Mr. Arthur V. Dienhart Vice President of Engineering 414 Nicollet Mall Minneapolis, Minnesota 55401 cc:

Gerald Charnoff Shaw, Pittman, Potts, Trowbridge

& Madden

,Environmental Library of Minnesota 1222 S.

E. 4th Street Minneapolis, Minnesota 55414

UNITED STATES OF APKRICA ATOMIC ENERGY COMMISSION zg 73

/

In the Hatter of NIAGARA MOHAWK POWER CORPORATION (Nine Mile Point, Unit No. 1)

Docket No. 50-220 CERTIFICATE OF SERVICE I hereby certify that copies of the annexed letter dated January 23, 1973, in the captioned matter, have been served on the following by deposit in the United States mail, first class, or air mail, this 23rd day of January, 1973:

Arvin E. Upton, Esq.

LeBoeuf, Lamb, Leiby

& MacRae 1821 Jefferson Place, N.W.

Washington, D.C.

20036

Chairman, Atomic Safety and Licensing Board Panel U.S. Atomic Energy Commission Washington, D.C.

20545 Secretary of the Commission U.S. Atomic Energy Commission Washington, D.C.

20545

Chairman, Atomic Safety and Licensing Appeal Board U.S. Atomic Energy Commission Washington, D.C.

20545 Hr. Frank W. Karas Chief, Public Proceedings Staff Office of the Secretary of the Commission U.S. Atomic Energy Commission Washington, D.C.

20545 Bruce MacDonald

~l<gtPy STATE OF NEW YORK DEPARTMENT OF COMMERCE II2 STATE STREET AlBANY

d. BRUCE MACDONALD COVMSEL January 23, 1973 Bernard M. Bordenick, Esq.

Counsel for AEC Regulatory Staff U.S. Atomic Energy Commission Washington, D,C.

20545

Dear 1fr. Bordenick:

Re:

Niagara Mohawk Corporation (Nine Mile Point, Unit No. 1)

Docket No. 50-220 This is to confirm the understanding of the regulatory staff that the State of New York Atomic Energy Council did not intend to request a hearing by the filing of its petition in the above matter.

Sincerely,

'wiC

,~ J. Bruce MacDonald Deputy Commissioner and Counsel NYS Department of Commerce and Counsel to the Atomic Energy Council