ML20249B338

PNO-76-068:on 760407,during Insp of Suppression Pool (Torus) supports,31 of 40 Hold Down Nuts Were Found Backed Off Studs.Licensee Developing Procedure to Tighten Nuts in Question to Specified Torque.State of Nj Informed

ML20249B338
Person / Time
Site:	Oyster Creek
Issue date:	04/08/1976
From:	Dreher F, Roy G, Thompson D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
PNO-76-068, PNO-76-68, NUDOCS 9806220334
Download: ML20249B338 (2)

Text

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[ / M I2efMW'U4tdf_ g $ ipril 8, 1976

. Y Nf i PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE --PNO '76-68 l This preliminary notification constitutes EARLY notice of events of -

POSSIBLE safety or public interest significance. The information presented is as initially received without verification or evaluation

, and is basically all that is known by OIE staff as of 8:30 a.m. on date of this notification. IT SHOULD BE SPECIFICALLY NOTED THAT THIS j NOTIFICATION MAY CONTAIN INFORMATION THAT LATER MAY BE DETERMINED TO j BE INACCURATE OR INCONSISTENT. AN OFFICE OF INSPECTION AND ENFORCEMENT '

NOTIFICATION OF AN INCIDENT OR OCCURRENCE (BLUE SHEET) SUBSEQUENTLY WILL BE ISSUED IF WARRANTED.

Facility: Oyster Creek (DN 50-219)

Jersey Central Power and Light Company Forked River, New Jersey

Subject:

LOOSE SUPPRESSION POOL HOLD-DOWN FASTENERS The Region I, Philadelphia, office was informed b'y the Oyster Creek plant superintendent that, during an inspection of suppression pool (torus)

supports, 31 of 40 hold down nuts were found backed off their studs. "

i 20 columns support the inner circumference of the suppression pool. These l

columns are each held in place by two threaded studs set in the base concrete.

The column base plate is then attached by nut fasteners installed on l the studs.

The licensee's inspection indicated that 9 nuts were close-up to the extent that a feeler gauge could not be inserted between the nut and base plate.

Tlie three worst cases indicated gaps of 1-1/4", 1-1/4" and 2-1/2". The remainder had gaps on the order of 1/8".

An analysis by the licensee's consultant indicated that the condition did not degrade torus performance capabilities and, therf ore, f did not compromise any safety aspects.

i , The licensee is developing a procedure to tighten the nuts in question to

! the specified torque. /

It is anticipated that this tightening will be completed within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Region I, Philadelphia, Pa. is investigating the generic aspects of the l j finding and frequency of licensee inspections.

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, Continued f , ,

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9006220334 760408 PDR I&E

, PNO-76-068 PDR p

Pcgs 2 ,*

, *..- April 2, 1976' Continued PNO-76-68

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The above information is current as of 3:00 p.m. on April 7,1976.

<' f Media interest is expected because of continued local interest in this facility and current interest in torus design.

The State of New Jersey j has been informed.* A press release is not planned.

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,.j Region J Philadelphia, Pa. received notification of this occurrence by telephone from the plant superintendent at 11:00 a.m. 4/7/76.

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Contact:

FADreher, IE x27261 . GWRoy, IE x27261 DThompson, IE x27541 Distribution:

Acting Chairman Rowden Commissioner Mason S. J. Chilk, SECY i

Commissioner Gilinsky C. C. Kammerer, CA G. F. Murphy, JCAE .

Commissioner Kennedy L. V. Gossick, EDO E. Volgenau, OIE J. A. Harris, PA B. C. Rusche, NRR J. La Fleur, ISP T. J. McTiernan, AIA K. R. Chspman, NMSS H. K. Shapar, ELD Transmitted: P Bldg h et,4 H Sti A.  ; MNBB h a.,; Luge  ;

PRELIMINARY NOTIFICATION - NOT FOR PUBLIC DISCLOSURE l

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