05000362/LER-2011-001, (SONGS) Unit 3 Regarding Missed TS LCO Surveillance Requirement When One Source Range Monitor Removed from Service
| ML110872000 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 03/26/2011 |
| From: | Bauder D Edison International Co, Southern California Edison Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 11-001-00 | |
| Download: ML110872000 (3) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3622011001R00 - NRC Website | |
text
SOUTHERN CALIFORNIA EDISON Douglas R. Bauder Plant Manager San Onofre Nuclear Generating Station An EDISON INTERNATIONAL Company March 26, 2011 U.S. Nuclear Regulatory Comm ission Document Control Desk Washington, D.C. 20555-0001 10 CFR 50.73 (a)(2)(i)B)
Subject:
Docket No. 50-362 Licensee Event Report No. 3-2011-001 San Onofre Nuclear Generating Station, Units 3
Dear Sir or Madam:
This submittal provides Licensee Event Report (LER) 3-2011-001 to report a missed Technical Specification Limiting Condition for Operation (LCO) required surveillance.
Neither the health nor safety of plant personnel or the public was affected by this occurrence.
If you require any additional information, please contact me.
Sincerely, Douglas R. Bauder Site Vice President and Station Manager Unit 3 LER No. 2011-001 cc:
E. E. Collins, NRC Regional Adm inistrator, Region IV G. G. Warnick, NRC Senior Resident Inspector, San Onofre Units 2 &3 P.O. Box 128 San Clemente, CA 926 72 (949) 368-6768 PAX 86768 Fax: (949) 368-6183 Doug.Bauder@sce.com
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (10-2010)
LICENSEE EVENT REPORT (LER)
APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 1. FACILITY NAME San Onofre Nuclear Generating Station (SONGS) Unit 3
- 2. DOCKET NUMBER 05000362
- 3. PAGE 1 of 2
- 4. TITLE Missed TS LCO Surveillance Requirement When One Source Range Monitor Removed From Service
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL NUMBER REV NO.
MONTH DAY YEAR FACILITY NAME SONGS Unit 3 DOCKET NUMBER 05000362 1
25 11 2011-001-00 3
26 11 FACILITY NAME N/A DOCKET NUMBER N/A
- 9. OPERATING MODE 5
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply) 20.2201(b) 20.2203(a)(3)(i) 50.73(a)(2)(i)(C) 50.73(a)(2)(vii) 20.2201(d) 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 20.2203(a)(1) 20.2203(a)(4) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 20.2203(a)(2)(i) 50.36(c)(1)(i)(A) 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A) 20.2203(a)(2)(ii) 50.36(c)(1)(ii)(A) 50.73(a)(2)(iv)(A) 50.73(a)(2)(x) 20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(v)(A) 73.71(a)(4) 20.2203(a)(2)(iv) 50.46(a)(3)(ii) 50.73(a)(2)(v)(B) 73.71(a)(5) 20.2203(a)(2)(v) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(C)
OTHER 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B) 50.73(a)(2)(v)(D)
Specify in Abstract below or in NRC Form 366A
- 10. POWER LEVEL 0 %
- 12. LICENSEE CONTACT FOR THIS LER NAME Douglas R. Bauder, Site Vice President and Station Manager TELEPHONE NUMBER (Include Area Code) 949-368-9275 CAUSE SYSTEM COMPONENT MANU-FACTURER REPORTABLE TO EPIX
CAUSE
SYSTEM COMPONENT MANU-FACTURER REPORTABLE TO EPIX N/A N/A
- 14. SUPPLEMENTAL REPORT EXPECTED YES (If yes, complete 15. EXPECTED SUBMISSION DATE)
NO
- 15. EXPECTED SUBMISSION DATE MONTH DAY YEAR ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On January 25, 2011, it was discovered that on January 24, 2011, at 1715 PST, with Unit 3 in Mode 5, SCE found Source Range Monitoring (SRM) Channel 2 had been removed from service at 0843 PST without implementing the Shutdown Margin (SDM) verification within four hours as required by Technical Specification Limiting Condition for Operation (LCO) 3.3.13 Condition A.2.
The Reactor Coolant System (RCS) boron concentration was being monitored for SDM, however the 0935 PST sample was not reviewed until 1320 PST and the SDM verification procedure was not completed until 1755 PST.
SRM Channel 2 had been temporarily made operable, suspending planned maintenance work.
When the maintenance work on SRM Channel 2 was resumed, the work control operator failed to activate the administrative controls to reinitialize the LCO surveillance. The on coming operating shift identified the deficiency by reviewing the control board status. Corrective Action was taken to improve the controls for resuming suspended maintenance work.
There was no safety significance. Boron concentration was stable, there were no temperature changes or activities with potential to add positive reactivity (control rods were de-energized), and the redundant SDM Channel 1 was in service during this period.
NRC FORM 366 (10-2010)(10-2010)
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE San Onofre Nuclear Generating Station (SONGS) Unit 3 05000362 YEAR SEQUENTIAL NUMBER REV NO.
2 of 2 2011
-- 001 --
00
=
Background===
The boron concentration in the Reactor Coolant System (RCS) is monitored to maintain the Shutdown Margin (SDM) when the reactor is shutdown. SDM is the amount by which the reactor is subcritical. Two Source Range Monitoring (SRM)[IG] instrument channels provide indication of the reactor status.
Technical Specification (TS) Limiting Condition for Operation (LCO) 3.3.13 Condition A.2, for one SRM channel inoperable, requires performing the SDM verification within four hours, and once every twelve hours thereafter. Although periodic monitoring of the boron concentration for SDM was in effect at the time of the occurrence, the surveillance procedure was not completed within the four hour time limit. The failure to comply with LCO 3.3.13 is being reported under 50.73(a)(2)(i)(B) Any operation or condition which was prohibited by the plants Technical Specifications.
Description of Event
On January 24, 2011 at about 0843 PST, with Unit 3 in Mode 5, and SRM Channel 1 in service, SRM Channel 2 was removed from service to continue removing temporary equipment installed for the U3 Cycle 16 refueling outage. An RCS boron concentration sample was taken, as requested by the control room, at 0935 PST. However, the results were not reviewed by the control room staff until 1320 PST because it was not recognized completion of the verification procedure was required within four hours. The on-coming control room shift reviewing the status of the control board at 1715 PST found the deficiency and completed the SDM verification procedure at 1755 PST. The missed LCO was discovered on January 25, 2011, at 0210 PST.
Cause of the Event
The administrative controls for tracking entry to the LCO were not activated as required. The work on SRM Channel 2 was originally authorized to start on January 21. Subsequently, an electrical bus outage required removing SRM Channel 1 from service and delayed the work on SRM Channel 2, returning SRM Channel 2 to service on January 22. When the SRM Channel 2 work was resumed on January 24, the work control operator failed to reinitialize the TS LCO administrative tracking process with the control room.
Consequently, when the control room directed continued boron sampling as required for one SRM channel out of service, they did not verify the LCO entry clock had restarted, and did not review the four hour requirement.
Corrective Actions
The SDM surveillance was completed. Process changes were made to ensure the administrative controls for required TS related actions are reissued when maintenance is suspended and resumed at a later time.
Safety Significance
There was no safety significance to this event. A review of computer data showed there were no changes in RCS temperature, nor was there a decrease in boron concentration. There were no activities taking place that could have added positive reactivity before the surveillance was completed (control rods de-energized),
and the redundant SRM Channel 1 remained in service during this time.
Operating Experience Previous Similar Events - SCE reported a similar event with a different underlying cause in LER 2-2007-002.