ML20127L245

Forwards NRC Bulletin 74-10A Re Failures in 4-inch Bypass Piping at Dresden-2

ML20127L245
Person / Time
Site:	Monticello, Dresden
Issue date:	12/17/1974
From:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:	Wachter L NORTHERN STATES POWER CO.
References
IEB-74-10A, NUDOCS 9211230468
Download: ML20127L245 (3)

Text

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UNITED STATES g

ATOMIC ENERGY COMMISSION

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DIRECTOR ATE OF REGULATORY OPER ATIONS REGION lli ,

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i 799 ROOSEVELT ROAD 0121856 2860 GLEN ELLYN ILLINOIS 6o137 December 17, 1974 Northern States Power Company Docket No. 50-263 A'ITH: Mr. Leo Wacther, Vice President Fower Production and System Operation 414 Nicollet Hall Minnaapolis, Minnesote 55401 Gentlemen Roelosed is RO Dulletin 74-10A, which amends the description of the cireumstances discussed in R0 Bulletin 74-10 and requests additional actions by you.

Should you have questions regarding this Bulletin or the actions roguested of you, please sentact this office.

Sincerely yours, i

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James G. Keppler ,

Regional Director Enclosure RO Du11etta No.74-10A Approved by GAO, 5-180225 (R0072), eleeranee supires 7-31-77.

Approval t'as gives under a blanket elesrance specifically for identified generic problems.

bee DR Central Files N

'R0 Files PDR Local PDR OGC, Beth, P-506A '\

Anthony Roisman, Esq.

1230468 741217 G ADOCK 05000263 4) .4 ,

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December 17, 1974 DRO Bulletin No.74-10A FAILURES IN 4-INCH BYPASS PIPING AT DRESDEN-2

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REFERENCE:

R0 BULLETIN NO. 74-10, DATED 9/19/74)

DESCRIPTION OF CIRCUMSTANCES (AMENDED):

The Commonwealth Edison Company notified the Region III Office of the Directorate of Regulatory Operations by telephone on December 13, 1974, of the finding of additional through-wall cracks in the 4-inch diameter bypass loop around the dischargo valve of the "B" recirculation pump at the Dresden-2 facility. The circumferential cracks were located adjacent to the heat affected zone of a weld which joins the'"B" bypass loop piping to a weldolet fitting on the 28-inch diameter main coolant recir-culation piping.

The cracks were revealed during a planned ultrasonic reexamination of the bypass piping as a part of the inservice inspection program at  !

Dresden-2. Similar ultrasonic examination of the same veld in mid-September 1974 revealed no evidence of cracks at that--time.

The Dresden-2 facility is currently shut down for refueling. All welds in the 4-inch bypass piping are to be reexamined during this shutdown.

The licensee is evaluating the significance of the cracks which have been detected as well as procedures for their' repair.

ACTIONS REQUESTED OF LICENSEES (AMENDED):

For all boiling water reactor facilities of jet-pump design with operating license

1. Reevaluate the results of ultrasonic and other examinations con-ducted previously in response to R0 Bulletin 74-10 or es part'of the baseline inservice inspection for those facilities not examined

in response to RO Bulletin 74-10.

i Notify this office by telephone by December 23, 1974, and reaffirm in writing by December 30, 1974, of the results of your reevaluation.

, 2. Reexamine (by ultrasonic or ot. suitable volumetric inspection technique) all accessible welds in the bypass piping lines around

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following conditionst i

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DRO Bulletin No.74-10A a. If presently at cold shutdown and scheduled to remain in this condition for 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or more, prior to resuming power operation.

b, If presently at a condition other than cold shutdown, at such time that (within the sensitivity specified in paragraph C.S.

of Regulatory Guide 1.45) any reactor coolant leakage detection system indicates, within a period of four hours or less, either an increase in unidentified leakage to twice the determined normal rate of unidentified Icakage or an increase in the rate of unidentified leakage by two (2) gpm or more. (In no case, however, shall the rate of leakage exceed that specified in the technical specifications without those actions required of the technical specification being taken.)

c. Next cold shutdown, regardless of duration.

Notify this office in writing, within 10 days following their completion, of the results of the reexaminations conducted in response to this Bulletin. Your written notification should also include a brief description of the examination-technique and procedures employed, as well as a description of any special engineering disposition or repairs necessitated by the results of these reexaminations.

A copy of all written notifications to this office (including all attachments) should be sent to the Assistant Director for Construction and Operations, Directorate of Regulatory Operations, AEC Headquarters in Washington, D. C.

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