PNO-I-87-020, on 860311,util Informed NRC That Unique MSIV Ball Valves Will Be Replaced W/Typical BWR Y Pattern Globe Valves Due to Problems W/Prototype Testing of Ball Valves. Replacement Expected to Take 3 Months

From kanterella
Jump to navigation Jump to search
PNO-I-87-020:on 860311,util Informed NRC That Unique MSIV Ball Valves Will Be Replaced W/Typical BWR Y Pattern Globe Valves Due to Problems W/Prototype Testing of Ball Valves. Replacement Expected to Take 3 Months
ML20207S272
Person / Time
Site: Nine Mile Point Constellation icon.png
Issue date: 03/12/1987
From: Gallo R, Linville J
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
References
PNO-I-87-020, PNO-I-87-20, NUDOCS 8703190223
Download: ML20207S272 (1)


DCS No: 50410870311 Dato: March 12, 1987 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-I-87-20 This preliminary notification constitutes 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: Licensee Emergency Classification:

Niagara Mohawk Power Corporation Notification of Unusual Event Nine Mile Point Unit 2 Alert Oswego, New York Site Area Emergency DN 50-410 General Emergency X Not Applicable

Subject:

MAIN STEAM ISOLATION VALVE (MSIV) REPLACEMENT On March 11, 1986, Niagara Mohawk Power Corporation management met separately with-R2gion I and NRR management to inform the NRC that they had decided to replace the unique MSIV ball valves with the typical BWR "Y" pattern globe valves due to continued problems with the prototype testing of the ball valves. Prototype testing, completed through March 9,1987 showed no signs that a redesigned packing modification could be implcmented which would stop the leakage at the body to seat joint. The licensee has b:rn making contingency plans to replace the ball valves since September 1986, when the valves initially were found to leak by their seats. Presently the replacement valves, tanufactured by Rockwell, are in Buffalo ready for shipment to the site. The entire process, from removal of the ball valves through preoperational testing of the globe valvas, is expected to take three months.

The licensee informed the news media on March 11, 1987 and plans a press briefing for 10:00 a.m. March 12, 1987.

Tha State of New York has been notified.

CONTACT: J. Linville R. Gallo 488-1122 488-1225 DISTRIBUTION:

H. St. MNBB _ _ Phillips E/W Willste Mail: ADM:DMB Chairman Zech EDO NPR IE NMSS DOT:Trans only Co'mm. Bernthal PA OIA RES Ccmm. Roberts ELD AE00 NRC Ops Crt Comm. Asselstine Ccmm. Carr ACRS Air Rights INPO----

SECY SP NSAC----

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

~

(Reactor Licensees) lo 50 8703190223 870312 i

' )'

PDR I&E PNO-I-87-020 PDR -

i

$j