05000362/LER-2004-002

LER-2004-002, Station ManagerEDISON' San Onofre
An EDISON INTERNATIONALS Company
May 8, 2006
U.S. Nuclear Regulatory Commission
Document Control Desk
Washington, D.C. 20555-0001
Subject:DDocket Nos. 50-362
Licensee Event Report No. 2004-002-01
San Onofre Nuclear Generating Station, Unit 3
Reference: Raymond Waldo (SCE) letter to NRC Document Control Desk, "Licensee
Event Report No. 2004-002", dated August 9, 2004.
Dear Sir or Madam:
In the letter referenced above, SCE provided a Licensee Event Report (LER) in
accordance with 10CFR50.73(a)(2)(i)(B) to report violations of Technical Specifications
due to an incomplete post-maintenance calibration of Logarithmic Power Level-High
Channel "A". When this LER was first submitted, SCE's cause evaluation was in
progress. SCE is revising this LER to incorporate the updated findings from the cause
evaluation.
Any actions listed are intended to ensure continued compliance with existing
commitments as discussed in applicable licensing documents; this LER contains no new
commitments. If you require any additional information, please so advise.
Sincerely,
a-sLi
LER No. 3-2004-002-01
cc: B. S. Mallet NRC Regional Administrator, Region IV
C. C. Osterholtz, NRC Senior Resident Inspector, San Onofre Units 2 & 3
P.O. Box 128
San Clemente, CA 92674-0128
949-368-9263/PAX 89263
Fax 949-368-6183
breigdp@songs.sce.com
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1. FACILITY NAME 2. DOCKET NUMBER 3. PAGE
San Onofre Nuclear Generating Station (SONGS) Unit 3 05000362 1 OF 3
4. TITLE
Incomplete post-maintenance calibration of Logarithmic Power Level-High Channel "A" results in Technical
Specification Violations.

San Onofre Nuclear Generating Station (Songs)
Event date:	06-06-2004
Report date:	05-08-2006
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
3622004002R01 - NRC Website

1. FACILFTY NAME 2. DOCKET NUMBER 6. LER NUMBER PAGE (3) San Onofre Nuclear Generating Station (SONGS) Unit 3 05000362 YEAR 2004 —002 — 01 Event Date:� June 6, 2004 Discovery Date:� June 8, 2004 Reactor Vendor:� Combustion Engineering Mode:� Mode 3 — Hot Standby Power:� 0 percent

Background

SONGS Unit 3 Reactor Protection System (RPS) [JC] includes four channels ("A" through "D") of Logarithmic Power Level-High trip (Log Power) to protect against an unplanned criticality from a shutdown condition. A reactor trip is initiated by the Logarithmic Power Level-High trip at a less than or equal to 0.93 percent of Rated Thermal Power (RTP) unless this trip is bypassed by the operator. The bypass is automatically removed when the logarithmic power level decreases below 1E-4 percent of RTP.

Technical Specification (TS) 3.3.1, RPS Instrumentation-Operating, and TS 3.3.2, RPS Instrumentation-Shutdown, together require four Log Power and Operating Bypass Removal channels to be Operable in Modes 2, 3, 4, and 5 when any reactor trip circuit breaker (RTCB) [BKR] is closed and any control element assembly is capable of being withdrawn. If one channel of Log Power becomes inoperable in Modes 2, 3, 4, or 5, these TSs require the inoperable channel to be placed in bypass within one hour and to be returned to Operable status prior to entering Mode 2 following the next entry into Mode 5.

On January 26, 2004, Action Request 040101660 was written when Unit 3 Log Power Channel "A" failed a TS surveillance because it was reading about one decade lower than the other three channels. Operators bypassed this channel until no longer required by TS 3.3.2, RPS Instrumentation—Shutdown, and TS 3.3.1, RPS Instrumentation- Operating.

On June 4, 2004, at 0445 PDT, plant operators manually tripped the Unit 3 reactor due to degraded circulating water pump [13] suction caused by heavy influx of sea grass across the traveling screens [SCN] during very low tide conditions. Unit 3 remained in Mode 3 until it was returned to full power operation about two days later. That event was reported to the NRC in LER 3-2004-001.

Description of the Event

Although not required by the TS, SCE used the June 4, 2004 outage as an opportunity to repair Log Power Channel "A." Plant technicians (utility, non-licensed) replaced a discriminator card and performed the TS-required channel calibration procedure. Control Room (utility, licensed) personnel returned the channel to Operable status at 2305 PST on June 5, 2004 and then proceeded with an orderly plant startup. Unit 3 entered Mode 2 at 0023 PST on June 6, 2004 and Mode 1 at 0317 PST on the same date.

On June 8, 2004 (discovery date), plant personnel (utility, non-licensed) reviewing Log Power channel "A" maintenance records noticed a conflict between the "work done" section of the maintenance order (MO) and the steps signed as "complete" in the calibration procedure. After investigating the conflicting information, it was determined that part of the calibration procedure was not performed in accordance with the procedural requirements. Control Room personnel were informed and declared this channel inoperable.

Completing a plant startup without placing a TS-inoperable Log Power Channel in bypass within one hour resulted in the following TS violations:

San Onofre Nuclear Generating Station (SONGS) Unit 3 05000362 2004 —002 — 01 1. TS 3.3.2 requires four channels of Log Power to be Operable whenever the plant is in Modes 3, 4, or 5 and with one or more reactor trip circuit breakers (RTCB) closed and any control element assembly capable of being withdrawn. Action "A" requires an inoperable channel of Log Power to be placed in bypass within one hour, which was not done.

2. TS 3.3.1 requires four channels of Log Power to be Operable when any RTCB is closed. Action "A" requires an inoperable channel of Log Power to be placed in bypass within one hour, which was not done.

3. TS 3.0.4 requires an LCO to be met prior to entry into a Mode or other condition specified in the LCO applicability statement. TS 3.0.4 was not met because operators changed plant Mode without having Log Power Channel "A" in bypass.

SCE is providing this report in accordance with 10 CFR 50.73(a)(2)(i)(B).

Cause of the event:

This event resulted from a miscommunication between Maintenance personnel during a shift turnover. During the day shift, Maintenance personnel found they could not complete the channel calibration procedure (required to return the log channel to Operable status) because the available test equipment did not meet all the acceptance criteria. Because the calibration procedure could not be completed, Management decided to complete functional testing, return the maintenance order to planning status, and start up the plant with the Log Power Channel "A" bypassed (and not operable) as allowed by the TSs. During the turnover meeting, the oncoming swing shift supervisor misunderstood the message that the paperwork should be returned to planning status, without returning the Log Power Channel "A" to service. Instead, the swing shift supervisor, after verifying the functional test was performed satisfactorily, incorrectly signed off the work as being complete and informed Operations that the equipment could be returned to Operable status.

Corrective Actions:

SCE counseled/coached the individuals as appropriate. The expectation to use formal communication during turnovers was reinforced by a communication to site personnel on September 15, 2004 (AR 040101660). Other related corrective actions that were taken include training and proceduralizing the use of communications as an event defense (AR 050500737). Additional corrective actions may be identified and implemented.

Safety Significance:

This event had no safety significance. Log Power instrumentation Channels "B", "C", and "D" were unaffected by this occurrence and were fully Operable. As noted in the background section of this report, the TS allows continued operation with one channel of Log Power in bypass.

Additional Information:

In the past three years, SCE has not reported any other occurrences placing an RPS channel in service with an incomplete TS calibration.