L-2007-137, Technical Specification Special Report, Inoperable Containment Sump Wide Range Level Channel B

Technical Specification Special Report, Inoperable Containment Sump Wide Range Level Channel B

ML072540685
Person / Time
Site:	Saint Lucie
Issue date:	08/31/2007
From:	Johnston G Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2007-137
Download: ML072540685 (3)

Text

Florida Power & Light Company, 6501 S. Ocean Drive, Jensen Beach, FL 34957 August 31, 2007 FPL L-2007-137 10 CFR 50.4 10 CFR 50.36 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Re: St. Lucie Unit 1 Docket No. 50-335 Date of Event: August 7, 2007 Technical Specification Special Report Inoperable Containment Sump Wide Range Level Channel B The attached special report is being submitted pursuant to the requirements of St. Lucie Unit 1 Technical Specification 3.3.3.8 ACTION 4, and Technical Specification 6.9.2. This report provides notification that channel "B" of the containment sump wide range level instrument is inoperable.

As described in the attached special report, repair of the inoperable containment sump wide range level instrument could not be performed at power, and the instrument will be repaired at the next outage of sufficient duration, but no later than the next refueling outage.

Please contact us if there any questions on this information.

Very truly yours, GLJ/DLC Attachment an FPL Group company

L-2007-137 Attachment Page 1 of 2 SPECIAL REPORT

1. TITLE St. Lucie Unit 1 Inoperable Containment Sump Wide Range Level Channel B.

2. EVENT DESCRIPTION On August 8 2007, with St. Lucie Unit 1 in Mode 1, the channel B of containment sump wide range level signal trended slightly higher with this channel being placed out of service. St. Lucie Unit 1 Technical Specification (TS) 3.3.3.8 ACTION 4 was entered, which states:

ACTION 4 - With the number of OPERABLE Channels one less than the Total Number of Channels shown in Table 3.3-11, either restore the inoperable channel to OPERABLE status within 7 days if repairs are feasible without shutting down or prepare and submit a Special Report to the Commission pursuant to the specification 6.9.2 within 30 days following the event outlining the action taken, the cause of the inoperability and the plans and schedule for restoring to OPERABLE status.

A containment sump wide range level channel utilizes three level probes. St. Lucie Unit 1 TS 4.3.3.8 requires each channel be demonstrated operable by performing both a channel check and a channel calibration.

3. CAUSE OF THE EVENT Plant engineers and maintenance personnel investigated and evaluated this channel's level signal and concluded that all portions of the instrument loop outside of containment is working correctly. The instrument loop malfunction is definitely located inside containment, information is indicative of a possible sticking reed switch on the sensor in the sump. High radiation levels in this area when operating preclude any further troubleshooting, and the precise problem will be located when access to containment is achieved.

4. ACTION TAKEN St Lucie Unit 1 TS 3.3.3.8 ACTION 4 was entered on August 7, 2007, when the containment sump wide range level channel B failed.

FPL troubleshooting determined that the failed containment sump wide range level channel B could not be repaired at power.

The Unit 1 containment sump wide range level channel B will be investigated and returned to service at the next refueling outage or the next outage that is long enough to accommodate this work. Work order (WO) 37016268 has been issued to track this action.

L-2007-137 Attachment Page 2 of 2

5. SCHEDULE FOR RESTORING SYSTEM The Unit I containment sump wide range level channel B will be returned to service at the next outage of sufficient duration, and no later than the end of the next refueling outage (SL 1-22).