ML020790552

Special Report Re Channel 12 Chamber Water Level Indicator Inoperable

ML020790552
Person / Time
Site:	Nine Mile Point
Issue date:	03/04/2002
From:	Hopkins L Constellation Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NMP1L 1648
Download: ML020790552 (2)

Text

P.O. Box 63 Lycorning, New York 13093 Constellation Nuclear March 4, 2002 Nine Mile Point N L14 Nuclear Station March 48 A Member of the Constellation Energy Group U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 RE: Nine Mile Point Unit 1 Docket No. 50-220 DPR-63 Water Level

Subject:

Special Report, Channel#12 Suppression Chamber IndicatorInoperable Gentlemen:

Mile Point Unit 1 Technical In accordance with Action Statement 4.a of Nine Instrumentation Action Specification Table 3.6.11-2, Accident Monitoring (NMPNS) is submitting the Statements, Nine Mile Point Nuclear Station, LLC of Channel #12 Suppression following Special Report concerning the inoperability Chamber Water Level indicator.

Descriptionof Event hours, Channel #12 Suppression On February 16, 2002, at approximately 0205 declared inoperable when it drifted Chamber Water Level indicator LI-58-05A was outside its loop accuracy of +/- 0.2 feet.

Suppression Chamber Water Level Previously, on January 25, 2002, Channel #12 erratic behavior. The indication was declared inoperable when it exhibited voltage on the power supply.

investigation determined that the cause was ripple Report, letter NMIP1L 1641, dated This condition was discussed in NMPNS Special the repair of the power supply.

February 8, 2002, with the corrective action being and Channel #12 On February 13, 2002, the power supply was repaired to an operable condition. A Suppression Chamber Water Level indication restored the indication performance on review to determine if a relationship exists between cause determination.

January 25 th and February 16th will be part of the indication Channel #11 is operable.

Redundant Suppression Chamber Water Level Samba'

Page 2 NMP1L 1648 Cause of Event Level indication The cause of the Channel #12 Suppression Chamber Water Channel #12 malfunction has not been determined. The malfunctioning Model 11 53DA-5 Suppression Chamber Water Level indication uses a Rosemount of the level transmitter. After discussions with Rosemount, and an evaluation cause of the indication response, NMPNS concluded that the most probable malfunction is due to Channel #12 Suppression Chamber Water Level indication failure of the transmitter or its capillary sensing line.

CorrectiveActions will be

1. The malfunctioning Rosemount Model 1153DA-5 transmitter replaced with a more reliable transmitter by April 5, 2002.

performed.

2. A failure analysis of the malfunctioning transmitter will be Suppression

3. The cause evaluation of the malfunction of the Channel #12 Chamber Water Level indication will be completed.

Very truly yours, LA L-L Lawrence A. Hopkins Unit 1 Plant General Manager LAH/KLE/jm cc: Mr. H. J. Miller, NRC Regional Administrator, Region I Mr. G. K. Hunegs, NRC Senior Resident Inspector Records Management