ML20207G408

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PNO-77-216:on 771201 with Plant in Refueling Outage,Cracks Found in Upper Tube Support Plate of Each Sg.Licensee Formulating Plans for Further Exam of Other Areas of Upper Tube Support Plate & Also Tube Support Below Upper One
ML20207G408
Person / Time
Site: Millstone Dominion icon.png
Issue date: 12/02/1977
From: Klingler G, Nolan F, Sniezek J
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
PNO-77-216, NUDOCS 9903120068
Download: ML20207G408 (1)


Text

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gp gcg Decembcr 2, 1977 V PRELIMIflARY Hu IFICATION OF EVENT OR UNUSUAL $UIENbE- 216 This preliminary notification constitutes EARLY notice of an event of 70f!IfBCE safety or publTc interest significance. The inf ormation presented is as initially received without verification or evaluation and is basically all that is known by IE staff on this date.

Facility: Northcast Nuclear Energy Company Millstone Point, Unit 2 Waterford, Connecticut (DN50-336)

Subject:

CRACKS IN STEAM GENERATOR UPPER TUBE SUPPORT PLATE On December 1,.1977 with the plant in a refueling outage, crack,1 were found in the upper tube support plate of each steam generafor. '8The cracks were discovered when a section of.this plate was being removed i for examination'related to the tube denting problem which is being ex-perienced in steam generators.

Only a s' mall area of the upper tube support plate of each steam generator has been examined to date, since access was made through a small hand hole port.

In addition to the steam generator tubes, this. plate has. holes to permit water and steam flow. Cracks were identified between tube holes anc' also ,

between tube and flow holes.

The licensee is formulating plans for further examinations of othe areas I of the upper tube support plate and also the tube support plate 1:sediately i below the upper one. The remaining tube supports in,each steam gener-s ators are an " egg crate" type design which would not have this type of i a cracking. ' "'

Media interest is expected because of past/ current problems with steam generators and attention being directed to these problems. The State of i Connecticut has been informed. A press release is not planned by the  !

licensee or NRC.

1 NRC, Region I (Philadelphia) received notification of this occurrence by telephone from the Plant Superintendent at 4:10 PM, December 1, 1977.

An NRC Inspector.on site obtained further information and is following the problem. This information is current as of 11:15 AM, December 2, 1977. - --

Contact:

GKlingler, IE x28019 FNolan, IE x28019 JSniezek, IE x28019 Distribution: Transmitted H St U ol g Chaiman Hendrie Commissioner Kennedy Commissioner Bradford S. J. Chilk, SECY C. C. Kammerer, CA O h

Commissioner Gilinsky (ForDistribution)

Transmitted: MNBB th Od P Bldg' 8/,' 0 4 E. Volgenau, IE L. V. Gossick, EDO E. G. Case, NRR Region % Q Q S. H. Hanauer, ED0 .

J. J. Fouchard, PA SS' Bldg @ 0 7 '(MAIL)

R. Hartfield, MIPC C. V. Smith, NMSS R. J. McTiernan, 0IA R. G. Ryan, OSP R. Minogue, SD

-J H. K. Shapar, ELD iip 903120068 771202 , "a" MINARY NOTIFICATION PDR 18 E PNO-77-216 PDR

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