PNO-I-86-050, on 860711,plant Shut Down Due to Repairs on Charging Pump a Not Completed within 72 H Limit.Delay Caused by Galling of Rotating Element Locking Nut.Further Delays Expected Due to Tube Cracking Problems

PNO-I-86-050:on 860711,plant Shut Down Due to Repairs on Charging Pump a Not Completed within 72 H Limit.Delay Caused by Galling of Rotating Element Locking Nut.Further Delays Expected Due to Tube Cracking Problems

ML20207B469
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	07/15/1986
From:	Mccabe, Swetland NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
References
PNO-I-86-050, PNO-I-86-50, NUDOCS 8607180055
Download: ML20207B469 (1)

DCS No: 50213860711 Data: July 15, 1986 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-I-86-50 This preliminary notification n.,stitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by the Region I staff on this date.

Facility: Connecticut Yankee Atomic Licensee Emergency Classification:

Power Company Notification of Unusual Event Haddam Neck Plant Alert Docket No. 50-213 Site Area Emergency Haddam Neck, Connecticut General Emergency ,

X Not Applicable

Subject:

UNSCHEDULED SHUTDOWN GREATER THAN 48 HOURS The Haddam Neck Plant was shut down on July 11, 1986, when the licensee determined that repairs to the "A" charging pump, which failed on July 8, would not be completed within

'the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> limiting condition for operation. The charging pump repair has been delayed by the galling of a rotating element locking nut and the associated removal and repair activities. It is expected to be returned to service on July 15.

Plant startup may be further delayed because of licensee and NRC concerns involving potential steam generator (SG) tube cracking problems in the tubesheet roli area of the tubes. Many previously undefined eddy current indications in this area have been identified as tube cracks. NRC and licensee evaluation of the preliminary test results had concluded that no immediate tube integrity problem exi.;ted. However, further licensee analysis in response to the June 26, 1986 NRC Safety Evaluation Report (SER) on this issue has identified questions on tube structural integrity in certain LOCA events. There is also a question on the validity of the leak-before-break conclusion in the SER for tube rupture events in the tubesheet area. The licensee plans to remain in hot shutdown pending resolution of these concerns.

Should it be determined that SG repairs are required before operation resumes, a 2-4 week outage for SG tube plugging / sleeving is expected by the licensee.

Region I and NRC Licensing will confer with licensee management on the justification for continued operation prior to plant startup.

The licensee and Region I will respond to media inquiries. The State of Connecticut has been informed.

This information is current as of 8 a.m., July 15, 1986.

CONTACT: Swetland McCabe 203-267-2571 488-1231 8607180055 060715 PDR I&E PNO-I-86-050 PDR g ~4 0 \

i

DISTRIBUTION:

H. St. MNBB Phillips E/W Willste Mail: ADM:dMB Chairman Zech EDO NRR IE NMSS DOT:Trans only PA OIA RES Com. Bernthal ELD AE0D Com. Roberts Com. Asselstine ACRS Air P,ights INP0----

SECY SP NSAC----

CA FDR Regional Offices TMI Resident Section RI Resident Office Licensee:

(Reactor Licensees)

Region I Form 83 (Rev. July,1986)

, _-._ _ . . _ - , _ _ . _ _ . . _ . _ _ _ . . _ _ .- ._