ML20126C203

From kanterella
Jump to navigation Jump to search
Summary of 760226 Meeting W/Representatives of Mark I OG in Bethesda,Md Re BWR Mark I Containment Evaluation
ML20126C203
Person / Time
Site: Monticello Xcel Energy icon.png
Issue date: 03/05/1976
From: Guibert J
Office of Nuclear Reactor Regulation
To:
Office of Nuclear Reactor Regulation
References
NUDOCS 9212220418
Download: ML20126C203 (4)


Text

__ _- _ , _ . . _ . - _ _.m._ _ _ _ _ _ . . _ _ _ _ _ _ _ _ _ - _ _ - m..

f j , g %g _ UNITEo $TATES _ .

I

  • n j db

. 'f 8% NUCLEAR REGULATORY COMMISSION

f. f .j WASHINGTON, D. C. 20S55 )V p'A e

s MAR 5 976 L

j

%, * . . .

  • p' t
DOCKETS NOS,
50-219, 50-220, 50-237, 50-245, 50-249,'50-254, 50-259, L 50-260fTo-263.50-265, 50-271, 50-277, 50-278, 50-293, J

50-296, 50-298, 50-321, 50-324, 50-325,-50-331,-50-333, j 50-341, 50-354, 50-355, and 50-366._  :

i. LICENSEES: Boston Edison Company, Carolina Power 6 Light Company, Commonwealth Edison Company, Detroit Edison Company, Georgia-g Power Company, Iowa Electric Light 6 Power Company, Jersey ,

3 Central Power 6 Light Company, Nebraska Public Power District, Niagara Mohawk Pcwer Company, Northeast Nuclear Energy Company, j Northern States Power Company, Philadelphia Electric Company,

. Power Authority State of New York, Public Service f ,ctric *

and Gas, Tennessee. Valley Authority, Vermont Ys-b ' Gar i Power Corporation.

(

FACILITIES: Oyster Creek Nuclear Generating Station, Nine Mile-Point

Unit 1, Pilgrim *1, Dresden Units 2
and 3, Millstone Unit.1, i Quad Cities Units:1 and 2, Monticello, Peach Bottom Units

{ 2 and 3, Browns Ferry Unit.1, 2 and 3, Vermont Yankee, 4 Hatch Units 1 and 2, Brunswick Units 1 and 2, Duane Arnold l Energy Center, Cooper, Fitzpatrick,-Enrico Fermi Unit 2, j and Hope Creek Units 1 and 2.

SUM 4ARY OF_ MEETING HELD ON FEBRUARY 26, 1976 TO DISCUSS'BWR MARK I CONTAINMENT 7

EVALUATION L Introduction l On February 26, 1976, a meeting was held-in Bethesda with. representatives

+

of the Mark I Owners Group and their -technical consultants to discuss recent I- developments regarding the structural: adequacy of torus support column welds

and proposed plans to promptly restore adequate margins of_ safety for the-torus column support systems at operating BhW s with the Mark I containment.

. Enclosure 1 is a list _of the meeting attendees g Summary i

i The NRC-staff. expressed it concern over information.recently obtained.during.

! _a working meeting between the staff and the representatives of-the Mark I.

Owners Group in San Jose'on February 19 and 20, 19_76._ This information

. demonstrated that the margin of safety _ for the_ welds at- the_ top of _ the -

torus support columns is lower than that which exists for other Mark Iz components. Because of this concern and the uncertainties irherent in the tests performed.to establish the hydrodynami_c loads anticipated during a postulated los_s-of-coolant raccident - (LOCA), the NRC - staff. requested that .-

i. the licensees of operating BWR's'with the Mark I containment _ propose plans i to promptly restore the margin of safety to at least"a factor of two, i

pu,-

9212220418.760305 '

l PDR ADOCK 05000263 p PDR

1 bbitiple Addressees MAR 5 G76 i

Representatives of each licensee described and discussed various operating modifications which would reduce the magnitude of the potential hydrodynamic loads associated with a postulated LOCA, such as use of an increased drywell pressure and decreased torus water level. Following these discussions the members of the Mark I Owner's Group indicated that they would enhance safety margins by pressuri:ing the containment to establish a differential 3 pressure of at least 1 psi between the drywell atmosphere and the torus.

It was agreed that this differential pressure would be established by March 1,1976 for those reactors currently in operation and prior to return to operation for those plants currently shutdown. The Mark 1 BWR licensees also committed to document this agreement by letters to be placed in the docket for each individual facility affected. The NRC staff concurred with the technical basis for this method of restoring the i Mark I containment structure margin of safety to about a factor of two.

lll [

//f, l .0..'/"

' John C. Guibert Operating Reactors Branch #3 Division of Operating Reactors cc: See next page l,

1 I

I e

h

.r. .

J f

I ENCLOSURE ATTENDANCE LIST NRC - MARK 1 OWNER'S j

i Nuclear Regulatory Commission Nebraska Public Power Co.

W. Paulson L. Liss Karl R. Goller R. E. Wilbur i R. L. Tedesco R. P. Lovei

) -I. Sihweil L. Shao Philadelphia Electric Company

} David C. Teng l V. Stello H. W. Vollmer R. E. Heineman R. S. Fleischmann A. Schwencer M. J. Cooney

D. Eis'enhut R. H. Logue C. Tan V. S. Boyer P. DiBenedetto R. P. Snaider Bechtel Power Corporation E. Verdery J. Guibert B. S. Shicker I. A. Stridiron H. Friend M. Grotenhuis H. A. Franklin ,

G. Lear G. Amir Tennessee Valley Authority M. Fairtile i T. J. Carter J. Carter J. C. Glynn R. Steffy

> T. M. Su Commonwealth Edison i

NUSCO R. L. Bolger

,' L. De1 George Robert-N Smart D. P. Galle Teledyne Sargent 6 Lundy N.-S. Celia Adolf Walser J. A. Hayward' i- W. E. Cooper NUTECH R. E. Keever

! Boston Edison N. W. Edwards'

i- K. A. Hoedeman S. L. Rosen G. R. Edwards H. O'Connor

. Iowa Electric Light S Power Company Kaiser Engineers

. K. A. Meyer i

D. W. Ogden Larry D. Root D. B. Heilig l

f-I

Lowenstein, Newman, Reis 6 Axelrad Georgia Power Company Kathleen H. Shea C. F. Head J. R. Jordan Jersey Central Power 5 Light Company Southern Services Inc.

E. F. O'Connor R. W. Wulf F. E. Ehrensperger T. T. Robin MPR Associates Detroit Edison Company Wm R. Schmidt S. J. Weems A. B. Harris M. J. Partridge. F. E. Gregor Northern States Power Company Public Service Electric 5. Gas Co.

s G. H. Neils F. M. Linn Yankee Atomic Energy Company Chicago Bridge and Iron T. D. Keenan F. L. Butler R. F. Reedy e Power Authority of the State of NY D. L. Whitt

2. Chila:1 Carolina Power and Light Company J. Helland W. Hultgren R. K. Cothren General Electric Niagara Mohawk Power Corp.

R. H. Bucihrola M. G. Mosier M. Felmis L. S. Gifford N. Shirley Electric Power Research Institute R. E. Pahler

(. Vermont Yankee J. W. Beck D. E. Vandenburgh i

l

[

l l

i

.. , - , , , . _ _ .