ML20004F341

Advises That IE Bulletin 81-14, Potential Overstress of Shafts on Fisher Series 9200 Butterfly Valves W/Expandable T-Rings, Was Sent to Listed Licensees on 810417

ML20004F341
Person / Time
Site:	Monticello, Dresden, Davis Besse, Palisades, Kewaunee, Point Beach, Prairie Island, Duane Arnold, Cook, Quad Cities, La Crosse, Big Rock Point, Zion
Issue date:	04/17/1981
From:	Carroll D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
NUDOCS 8106180184
Download: ML20004F341 (2)

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'o, UNITED STATES j

NUCLEAR REGULATORY COMMISSION s

REGION lli 790 ROOSEVELT ROAD

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GLEN ELLYN, ILLINOIS 6o137 APR l'l 1981 L'

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c4 ll Gentlemen:

The enclosed IE Information Notice No. 81-14 titled " Potential Overstress of Shafts on Fisher Series 9200 Butterfly Valves with Expandable T Rings" was sent to the licenseas listed below on April 17, 1981:

American Electric Power Service Corporation Indiana and Michigan Power Company D. C. Cook 1, 2 (50-315, 50-316)

Commonwealth Edison Company Dresden 1, 2, 3 (50-10, 50-237, 50-249)

Quad-Cities 1, 2 (50-254, 50-265)

Zion 1, 2 (50-295, 50-304)

Consumers Power Company Big Rock Point (50-155)

Palisades (50-255)

Dairyland Power Cooperative LACBWR (50-409)

Iowa Electric Light and Power Company Duane Arnold (50-331)

Northern States Power Company Monticello (50-263)

Prairie Island 1, 2 (50-282, 50-306)

Toledo Edison Company Davis-Besse 1 (50-346)

Wisconsin Electric Power Company Point Beach 1, 2 (50-266, 50-301) 810618 o ISq

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0 2-Wisconsin Public Service Corporation Kewaunee (50-305)

Sincerely, Dorothy E. Carroll, Chief Word Processing and Document Control Section

Enclosure:

IE Information Notice No. 81-14 RIII

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Carroll /np 4/17/81

SSINS No.:

6835 Accession No.:

8011040292 IN 81-14 i

UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF IPSPECTION AND ENFORCEMENT WASHINGTON, D.C.

20555 April 17, 1981 IE Information Notice No. 81-14:

POTENTIAL OVERSTRESS OF SHAFTS ON FISHER SERIES 9200 BUTTERFLY VALVES WITH EXPANDABLE T RINGS Descriotion of Circumstances:

Northern States Power Company recently informed NRC that the design of certain butterfly valves at Monticello Nuclear Generating Station contained a design l

error that shows the calculated maximum shaft stress to be underestimated.

The valves affected are Fisher Controls Company Series 9200 butterfly valves l

(6 to 48 inches) with axrandable T rings (inflatable seals) manufactured from 1968 to 1972.

In the c;dculation of the shaft stress, the length between the shaft bushing and the rttachment of the shaft to the valve disc used in the stress calculations was shorter than the actual length.

From discussions with the valve manufacturer, the cause of the difference in the design calcu-iation dimension and the actual dimension was that the ; haft bushings were recessed into the valve body to accommodate the pneumatic passages for the inflatable seals.

Evaluation of the design error for the valves at Monticello indicate that the maximum shaft stress in the closed position remains less than the minimum yield strength of the shaft material.

The licensee intends to keep the affected valves closed while operating and plans to replace the shafts with ones of higher strength material.

The potential consequences of the design error is that, under accident loading conditions, there is a possibility for excessive deformation of the shaft.

Therefore, these valves when closed under the dynamic conditions of a LOCA or, if already closed, may not seal essentially leaktight.

Since tnese valves are used primarily in the containment purge and vent lines, a substantial safety hazard would exist if these valves could not be closed or if there was excessive leakage past these valves.

Containment integrity therefore could not be assured.

The operability of containment purge and vent valves is item II.E.4.2 in the TMI Action Plan.

I The facilities identified that may have the Fisher valves include Duane Arnold, Monticello, Palisades, Peach Bottom Units 2 and 3, and Point Beach Units 1 and 2.

Discussions with the valve vendor indicate that the reviews of the valve calculations affected should be completed by mid-April.

This information is provided as an early notification of a significant safety matter that is still under review by the NRC staff.

It is expected that licensess will review the information for possible applicability to their plants.

If NRC evaluations so indicate, further licensee actions may be requested.

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s IN 81-14 April 17, 1981 l

Page 2 of 2 No written response to this information notice is required.

If you need i

additional information with regard to this matter contact the Director of the appropriate NRC Regional Office.

l Attachment-t Recently issued Information Notices i

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Attachment IN 81-14 Anril 17, 1981 RECENTLY ISSUED IE INFORMATION NOTICES Inf ormation Date of Notice No.

Subject Issue

. Issued to 81-13 Jammed Source Rack in a 4/14/81 Specified Irradiator Gamma Irradiator licensees 81-12 Guidance on Order Issued 3/31/81 All BWR facilities January 9, 1981 Regarding with an OL or CP Automatic Control Rod Insertion on Low Control Air Pressure 81-11 Alternate Rod Insertion 3/30/81 All BWR facilities for BWR Scram Represents with an OL or CP f

,a Potential Path for Loss of Primary Coolant t

81-10 Inadvertant Containment 3/25/81 All power reactor Spray Due to Personnel facilities with an Error OL or CP i

81-09 Degradation of Residual 3/26/81 All power reactor Heat Removal (RHR) System facilities with an OL or CP 81-08 Repetitive Tailures of 3/20/81 All power reactor Limitorque Operator SNB-4 facilities with an Motor-to-Shaft Key OL or CP 81-07 Potential Problem with 3/16/81 All power reactor l

Water-Soluble Purge Dam facilities with an 3

Materials Used During OL or CP t

Inert Gas Welding 1

81-06 Failure of ITE Model 3/11/81 All power reactor K-600 Circuit Breaker facilities with an i

OL or CP 81-05 Degraded DC System at 3/13/81 All power reactor Palisades facilities with an OL or CP 81-04 Cracking in Main Steam 2/27/81 All power reactor Lines facilities with an OL OL = Operating Licenses CP = Construction Permits