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ENS 5637621 February 2023 22:02:00San OnofreNRC Region 4

The following information was provided by the licensee via email: On 2/21/2023 at 1402 (PST) SONGS (San Onofre Nuclear Generating Station) notified San Diego Regional Water Quality Control Board (SDRWQCB) regarding the results of a quarterly monitoring report. The report indicated the 24-effluent toxicity sample resulted in a 'Fail.' The results prompted a 24 hour notification to the SDRWQCB in accordance with the NPDES (National Pollutant Discharge Elimination System) permit. There was no significant effect on the health and safety of the public or the environment. Action Taken: SCE (Southern California Edison) Environmental notified the SDRWQCB via telephone voice mail at 1402 on 2/21/2023 followed by an e-mail describing the reason for the notification.

  • * * UPDATE ON 02/22/2023 AT 1403 EST FROM GUADALUPE ROBLES Jr. TO IAN HOWARD * * *

The following is a summary of information provided by the licensee via email: The licensee corrected the Unit from ISFSI to Unit 2 and the name of the quarterly test to note it was for the first quarter of 2023. Notified R4DO (Roldan-Otero), and NMSS Events Notification via email.

ENS 5461226 March 2020 03:00:00San OnofreNRC Region 4On 3/25/2020, SONGS (San Onofre Nuclear Generating Station) made required formal notifications to the California Office of Emergency Services at 2107 PDT, the San Diego Regional Water Quality Review Board at 2123 PDT, the San Diego Department of Environmental Health (CUPA) (Certified Unified Program Agency) at 2104 PDT, the National Response Center (NRC) at 2115 PDT, and the San Diego Coast Guard at 2149 PDT, concerning an approximate 7,000 gallon release of partially treated sewage to the Pacific Ocean. Both Sewage Treatment Plant effluent pumps were shut down and a state certified vendor is working to bring the treatment plant back to service.
ENS 5417923 July 2019 21:05:00San OnofreNRC Region 4On 7/23/2019 at 1405 PDT, San Onofre Nuclear Generating Station (SONGS) made a required formal notification to the Regional Water Quality Control Board for the state of California concerning a monthly oil sample of the oil removal system. The sample was analyzed to contain 42 ppm oil. This number exceeds the daily instantaneous maximum of 20 ppm. An additional sample was taken approximately one minute later and was analyzed to contain 8.1 ppm oil, potentially indicating a problem with the initial sample. Additional investigation is underway and a written follow-up report will be submitted to the Regional Water Quality Control Board within 5 days in accordance with the National Pollutant Discharge Elimination System permit. The licensee will inform NRC Region IV staff.
ENS 536423 October 2018 07:00:00San OnofreNRC Region 4At 1135 PDT on October 3, 2018, Southern California Edison (SCE) determined a SCE supervisor failed a random breathalyzer test for alcohol during a random Fitness-for-Duty (FFD) test. The employee's unescorted access to San Onofre Nuclear Power Plant has been suspended.
ENS 535805 September 2018 07:00:00San OnofreNRC Region 4At approximately 0608 Pacific Daylight Time (PDT), the Control Room was notified of a SONGS SCE (San Onofre Nuclear Generating Station Southern California Edison) employee experiencing a non-work related medical emergency outside the protected area, inside the owner controlled area. SONGS fire brigade was dispatched. Camp Pendleton Fire ambulance was requested. At 0644 (PDT) Camp Pendleton Fire department in communication with a doctor determined the victim is deceased. This notification is being made in accordance with 10 CFR 50.72(b)(2)(xi) for a situation related to the health of on-site personnel for which a notification to other government agencies is planned. California Highway Patrol and Coroner notified and expect the California Occupational Safety and Health Administration (Cal-OSHA) will be notified. NRC Region IV was notified (approximately 0900 PDT) as SONGS does not have a NRC resident inspector.
ENS 5225219 September 2016 19:30:00San OnofreNRC Region 4CEAt 1230 (PDT) on 9/19/16, SONGS (San Onofre Nuclear Generating Station) made an offsite notification to the San Diego Regional Water Quality Control Board in regards to an oily waste water release to the environment in excess of allowable limits. On 9/15/16, the Unit 3 oily waste sump overflowed. An estimated 1500 gallons was released to the intake which is pumped to the outfall. A sample was taken during the end of the overflow; no visual indication of oil and grease was noted. The sample analysis completed on 9/19/16 indicated a result that exceeded SONGS' NPDES (National Pollutant Discharge Elimination System) instantaneous maximum limit of 20 ppm; results were 34.4 ppm. The licensee will inform NRC Region IV staff.
ENS 5204727 June 2016 14:29:00San OnofreNRC Region 4CE
Westinghouse PWR 3-Loop

A non-licensed contract employee had a confirmed positive for alcohol following a for-cause fitness-for-duty test. The employee's access to the plant has been terminated. This information will be sent to the NRC Region 4 Office as San Onofre no longer has a resident.

  • * * RETRACTION ON 4/18/2018 AT 1308 EDT FROM TIM CUSICK TO STEVEN VITTO * * *

In the event report, the individual was described as a contract supervisor, thus meeting the reporting threshold. (the violation of the FFD policy was that he failed a for-cause test for alcohol). Recently, an NRC review of SONGS' 2016 Annual Fitness for Duty report found that SONGS described that test failure as 'not reportable' and that the labor category was 'Maintenance (Craft).' After reviewing the data, Access Authorization confirmed that the individual was a Union Maintenance Foreman (not a supervisor). The event was not reportable." SONGS will be notifying NRC Region 4. Notified R4DO (O'KEEFE) and FFD E-mail Group.

ENS 5155419 November 2015 21:00:00San OnofreNRC Region 4CEA review of operations log data revealed the Unit 2 Spent Fuel Pool temperature was allowed to drift approximately two degrees below the accepted analyzed temperature of 68 degrees F. The Extent of Condition is under review and the number of instances has not been fully determined. It is possible Unit 3 may have also been affected. As described in the San Onofre UFSAR, Section 9.1.2.3 'Design Basis for Fuel Storage and Handling,' one of the conditions assumed in meeting the design basis, is as follows: the most adverse delta-k (reactivity change) was analyzed for a pool temperature range from 68 degree F to 160 degree F. Although the temperature decrease is considered unlikely to have a significant impact on the results of the analysis, it is being reported under 10 CFR 50.72(b)(2) as an unanalyzed condition because there is at this time no analysis of record for the reduced temperature condition. There were and continue to be no observed, abnormal effects from the temperature drop below 68 degrees F, and no impact on the health or safety of plant personnel of the public. Re-analysis is in progress and is expected to demonstrate that the criticality acceptance criteria of 10CFR50.68 were met at all times. The licensee notified the Regional NRC Contact.
ENS 5101827 April 2015 22:27:00San OnofreNRC Region 4CENotification was made to the San Diego Regional Water Quality Control Board, and a message was left for exceeding the daily maximum parts per million (ppm) of oil and grease in the North Industrial Area Yard Drain Sump. Sump pumps are currently in "OFF" and the site is investigating. The oil in the drain sump did not reach "reportable quantities" and did not require notifying other Federal Agencies.
ENS 5047018 September 2014 19:35:00San OnofreNRC Region 4CEToday, at 1235 (PDT), San Onofre made the decision to notify offsite agencies (San Diego Regional Water Quality Control Board and Environmental Protection Agency if directed by SDRWQCB). Initial contact made with the San Diego Regional Water Quality Control Board was at 1333 (PDT) on 9/18/14. The subject of the report is listed below: On September 15, 2014, during a review of the NPDES (National Pollutant Discharge Elimination System) self-monitoring reports, SCE SONGS (Southern California Edison San Onofre Nuclear Generating Station) environmental staff discovered annual and semi-annual samples and required reports due in 2014 were not submitted on time and are now past due: - The missed samples and associated reports are non-radiological in nature - All parameters (physical and analytical data) in past Semi-annual and Annual reports have been in compliance with the NPDES permit. The licensee informed the NRC Resident Inspector.
ENS 5011514 May 2014 21:54:00San OnofreNRC Region 4CESONGS (is) making a 4-Hour notification per 10CFR72.75 (b) to the NRC Operations Center regarding the following: There has been a fire in the vicinity of the station. The fire is not on plant property and has not challenged station operations. Entry into SONGS' Emergency Plan and activation of the Emergency Response Organization is not required at this time. Because of the fire near the plant, Southern California Edison will be making a press release today to update the public as to the situation at the plant. The licensee notified an onsite NRC Inspector.
ENS 4997529 March 2014 04:10:00San OnofreNRC Region 4CE

On March 28, 2014 at 2110 PDT, station staff felt a minor seismic event, which was verified on the NEIC (National Earthquake Information Center). On-shift staff reviewed basis documentation and EAL (Emergency Action Levels) classification, and concluded the event was below the threshold to classify the event. During post event reviews (conducted on 3/31/2014), it has been determined that those events met the classification criteria for declaration of a Notification of Unusual Event for a seismic event as specified by the Emergency Plan. No emergency situation exists at this time.

Site personnel did perform the steps of the Earthquake abnormal operating procedure even though the entry requirements were not met.  There were no plant or equipment issues identified during the site walk downs.

The licensee has notified the NRC Resident Inspector, the State of California and other Local authorities.

ENS 4891311 April 2013 06:26:00San OnofreNRC Region 4CEAt 2253 PDT on 4/10/13, SONGS experienced degraded on-site radio communications during planned maintenance on radio systems. Radio communications were restored at 2315 PDT. The licensee will notify the NRC Resident Inspector.
ENS 4842821 October 2012 15:05:00San OnofreNRC Region 4CEThe control room was notified that an unknown quantity of H2 gas (classified as a minor coupling leak (identified with Snoop liquid leak detector)) is currently being released to the air from the Unit 2 Full Flow Hydrogen skid. The Environmental Protection Group reported the leak to the California Emergency Management Agency (Cal EMA) at 0809 PDT and the San Diego Department of Environmental Health at 0812 PDT lAW (plant) procedure S0123-XV-17.3, 'Spill Contingency Plan'. The Hydrogen Gas leak is currently still in progress. There is no gas collection areas. Maintenance is in the process of taking action to terminate the leak. The licensee notified the NRC Resident Inspector.
ENS 4834426 September 2012 00:07:00San OnofreNRC Region 4CEThe control room was notified by the Environmental Protection Group that 43 lbs of Freon was released (from an air conditioning unit) at the Administration Warehouse Supply/Shop, not in the Protected Area, and that it was reported to the California Emergency Management Agency at 17:19 PDT and San Diego County at 17:12 PDT, per lAW procedure SO123-XV-17.3, 'Spill Contingency Plan'. There is no longer a Freon release in progress. The licensee has notified the NRC Resident Inspector.
ENS 4823226 August 2012 19:39:00San OnofreNRC Region 4CE

A Notice of Unusual Event (NOUE) was declared at San Onofre due to an earthquake felt on site (EAL HU1.1). The US Geological Survey indicates that there was a 5.3 magnitude earthquake near Brawley California, about 125 miles southeast of the plant. There were no indication of any impact to site operations other than being felt by personnel. Equipment inspections and walkdowns are in progress. The licensee has notified state and local authorities. The NRC Resident Inspector will be notified. Notified other FEDS (FEMA, DHS, DHS NICC and Nuclear SSA via email).

  • * * UPDATE FROM BAYER TO HUFFMAN AT 1713 EDT ON 8/26/12 * * *

On August 26, 2012 at 1346 PDT, San Onofre exited the Unusual Event based on an earthquake felt on site. Shortly after exiting the UE, the licensee felt more shaking in the control room. The licensee confirmed with the US Geological Survey that there has been an aftershock. The aftershock was approximately the same magnitude (5.4) and location as the original earthquake (about 125 southeast of the site). The licensee declared another unusual event at 1403 PDT. The licensee will re-perform all equipment walkdowns and inspections. The NRC Resident Inspector has been notified and is reporting to the site. R4DO (Hay), NRR EO (Lubinski), and IRD (Gott) notified.

  • * * UPDATE AT 2352 EDT ON 8/26/2012 FROM ADAM BOW TO MARK ABRAMOVITZ * * *

Exited the NOUE HU1.1 - Earthquake at 2017 PDT on 8/26/12. The licensee will notify the NRC Resident Inspector. Notified the R4DO (Hay), NRR (Lubinski), IRD (Gott), DHS, FEMA, and DHS NICC.

ENS 4785620 April 2012 19:49:00San OnofreNRC Region 4CESan Onofre Unit 2 declared an Unusual Event at 1249 PDT today due to an electrical fire within a fire detection panel (2L319) in the Unit 2 turbine building. The fire was declared extinguished at 1314 PDT after the panel was de-energized. The location of the fire had no impact on plant operation, equipment, or personnel safety. No offsite assistance was necessary. The licensee exited the Unusual Event at 1341 PDT after the licensee confirmed that the fire was terminated and there was no ongoing risk to the plant. The licensee notified state and local authorities and the NRC Resident Inspector. The NRC Operations Center notified other Federal Agencies (DHS SWO, FEMA Ops, DHS NICC, and NuclearSSA via e-mail).
ENS 4774414 March 2012 18:20:00San OnofreNRC Region 4CE

On January 31, 2012, Unit 3 was shut down due to detection of a tube leak in one Steam Generator (SG). The shutdown was previously reported on Event Notification # 47628. Southern California Edison (SCE) has been performing in-situ pressure testing with non-radioactive water on tubes with significant wear indications. On March 14, 2012, at approximately 1120 PDT, Unit 3 Steam Generator (SG) E088 Tube R106 C78 did not meet the target performance criteria because leakage exceeded 0.5 gallons per minute at the maximum pressure achieved during the test (2,884 psig). This was the leaking tube that resulted in the Unit 3 shutdown. Subsequently, two additional tubes in Unit 3 SG E088 did not meet the target performance criteria as follows: at 1249 PDT, Tube R102 C78 exceeded 0.5 gallons per minute at 3,268 psig and at 1425 PDT, Tube R104 C78 exceeded 0.5 gallons per minute at 3,180 psig. These occurrences are reportable as an 8-hour notification to the NRC in accordance with 10 CFR 50.72(b)(3)(ii)(A). Testing and inspection of Unit 3 steam generator tubes is ongoing to determine the extent and cause of the observed wear. A follow-up notification will be made for additional in-situ pressure test failures. The extent and cause of the condition will be addressed in the follow-up licensee event report that will be submitted in accordance with 10 CFR 50.73(a)(2)(ii)(A). Defective tubes will be removed from service as required prior to Unit 3 plant startup. Unit 2 has been shut down since January 9, 2012 for a scheduled refueling outage. SCE previously performed in-situ pressure testing of the tube with the most wear in Unit 2. Results from this test demonstrated that the tube met the target performance criteria. The NRC Resident Inspector has been notified of this event.

  • * * UPDATE FROM LEE KELLY TO DONALD NORWOOD AT 2108 EDT ON 3/15/2012 * * *

In-situ pressure testing on Unit 3 steam generator tubes was started on March 14, 2012 and is ongoing. On March 15, 2012, four additional tubes in Unit 3 SG E088 did not meet the target performance criteria of three-times normal pressure conditions as follows: (1) At 1109 PDT, Tube R100 C80 failed at 4,739 psig; (2) at 1437 PDT, Tube R107 C77 failed at 5,160 psig; (3) at 1604 PDT, Tube R101 C81 failed at 4,889 psig; and (4) at 1734 PDT, Tube R98 C80 failed at 4,886 psig. Testing and inspection of Unit 3 steam generator tubes is ongoing to determine the extent and cause of the observed wear. Follow-up notifications will be made for any additional in-situ pressure test failures." The licensee notified the NRC Resident Inspector. Notified R4DO (Cain).

  • * * UPDATE FROM LEE KELLY TO JOHN SHOEMAKER AT 2115 EDT ON 3/16/12 * * *

In-situ pressure testing on Unit 3 steam generator tubes was started on March 14, 2012 and is ongoing. On March 16, 2012, one additional tube in Unit 3 SG E088 did not meet the target performance criteria of three-times normal pressure conditions as follows: at 1216 PDT, Tube R99 C81 failed at 5,026 psig. Testing and inspection of Unit 3 steam generator tubes is ongoing to determine the extent and cause of the observed wear. Follow-up notifications will be made for any additional in-situ pressure test failures. The licensee notified the NRC Resident Inspector. Notified R4DO (Cain).

ENS 476281 February 2012 01:30:00San OnofreNRC Region 4CEAt 1505 PST, Unit 3 entered Abnormal Operation Instruction S023-13-14 'Reactor Coolant Leak' for a steam generator leak exceeding 5 gallons per day. At 1549 PST, the leak rate was determined to be 82 gallons per day. At 1610 PST, a leak rate greater than 75 gallons per day with an increasing rate of leakage exceeding 30 gallons per hour was established and entry into S023-13-28 'Rapid Power Reduction' was performed. At 1630 PST, commenced rapid power reduction per S023-13-28 'Rapid Power Reduction'. At 1731 PST, with reactor power at 35% the Unit was manually tripped. At 1738 PST, Unit 3 entered Emergency Operation Instruction S023-12-4 'Steam Generator Tube Rupture'. At 1800 PST the affected steam generator was isolated. All control rods fully inserted on the trip. Decay heat is being removed thru the main steam bypass valves into the main condenser. Main feedwater is maintaining steam generator level. No relief valves lifted during the manual trip. The plant is in normal shutdown electrical lineup. Unit 2 is presently in a refueling outage and was not affected by this event. The licensee has notified the NRC Resident Inspector. The licensee has issued a press release.
ENS 4755023 December 2011 13:00:00San OnofreNRC Region 4CEAt 0500 PST 12/23/2011, ERDS communication VPN (Virtual Private Network) link with the NRC was interrupted during an automatic swap between computer servers. Restoration of the communication link is expected to be restored by 1430 PST. The licensee will notify the NRC Resident Inspector.
ENS 4748128 November 2011 14:00:00San OnofreNRC Region 4CEDuring the regeneration of the Unit 2 full flow condensate polishing demineralizer (FFCPD) resin, 5 percent sulfuric acid briefly overflowed from the bermed area. The majority of the acid went into the floor drains in the FFCPD area and then to the turbine building sump system. An estimated quantity of 2 gallons of sulfuric acid was released into the storm drains that discharged into the circulating water system. The quantity released was well below the reportable quantity. The fire department and environmental/hazmat team were contacted and responded. Precautionary notifications were made by SCE to: - California Emergency Management Agency - San Diego Dept. of Environmental Health. The cause of the leak has been corrected and no additional discharge is anticipated. The licensee will notify the NRC Resident Inspector.
ENS 474011 November 2011 21:50:00San OnofreNRC Region 4CE

On November 1, 2011 at 1450 PDT, San Onofre Unit 3 declared an ALERT and entered EAL HA3.1 due to an ammonia leak that prevented access to local areas. The plant is in a stable condition while the leakage is being secured. The turbine building on Unit 3 has been evacuated. Plant personnel are in the process of verifying no presence of ammonia in the turbine building. There was no impact on Unit 2.

  • * * UPDATE FROM KEN HOUSEMAN TO JOHN KNOKE AT 2115 EDT ON 11/01/11 * * *

At 1807 PDT licensee exited the ALERT and EAL HA3.1. The leak was at the Ammonia day tank and was flowing through an overflow vent into the berm. The high level in the Ammonia day tank was due to a leaking closed valve between the Demineralizer system and the ammonia bulk storage. The berm area was drained of all fluids. The wind direction caused the ammonia fumes to travel to the Unit 3 turbine deck. No off-site HAZMAT personnel came on-site. At 1756 PDT the precautionary evacuation of on-site personnel was terminated. Unit 2 was not affected from this event. The NRC Resident Inspector was notified. Notified NRR EO (Fredrick Brown), R4DO (Vincent Gaddy, IRDMOC (Jeff Grant), DHS (Hill), DOE (Doyle), USDA (Krauf), FEMA (Fuller) and HHS (Fajardo).

  • * * UPDATE FROM LEE KELLY TO VINCE KLCO AT 2228 EDT ON 11/01/11 * * *

On November 1, 2011, Southern California Edison notified the California Emergency Management Agency at 1755 PDT and the San Diego Department of Environmental Health at 1810 PDT that approximately 25 gallons of Ammonium Hydroxide was spilled under the Ammonium Hydroxide day tank located outside the Unit 3 turbine building. The spill was contained in a berm under the tank and subsequently cleaned up. Both Units 2 and 3 were at approximately 100% power at the time of the event. Notified the R4DO (Gaddy).

ENS 4728923 September 2011 00:30:00San OnofreNRC Region 4CE

This notification is for San Onofre Units 2 and 3, and is being made in accordance with 10CFR50.72(b)(2)(xi) to report a notification to another government agency regarding a spill of approximately 26000 gallons of untreated waste water (sewage). A pending report will be made to the San Diego County Dept. of Environmental Health regarding a untreated (sewage) waste water spill that occurred as San Onofre. The details that were communicated to the DEH are that at 1730 PDT a sewage spill was identified at SONGS in the North Industrial yard area. The leak was being collected in the yard drains and being discharged to the ocean. The sump discharge system has been secured stopping the release. The licensee will inform the NRC Resident Inspector.

  • * * UPDATE FROM LEE KELLY TO JOHN KNOKE AT 1325 EDT ON 9/26/11 * * *

On September 22, 2011, an untreated (sewage) waste water spill was discovered in the San Onofre North Industrial Area. Southern California Edison (SCE) notified the NRC at 1730 PDT on September 22, 2011, (Event No. 47289) in accordance with 10CFR50.72(b)(2)(xi). The California Emergency Management Agency was notified (Control #11-5652) at 2223 PDT and San Diego County Department of Environmental Health (DEH) was notified at 2239 PDT. The initial report to the NRC indicated the spill was approximately 26,000 gallons. The estimated size of the spill has subsequently been revised to approximately 7,000 gallons. At the time of the event, Units 2 and 3 were at 100 percent power. SCE notified the NRC Resident Inspectors about this occurrence and will provide them with a copy of this report. Notified the R4DO (Greg Werner).

ENS 472528 September 2011 22:38:00San OnofreNRC Region 4CEOn September 8, 2011 at 1538 PDT, the San Onofre Units 2 and 3 reactors tripped due to a grid disturbance. All control rods fully inserted. The EFAS (Emergency Feed Actuation System) initiated as expected for a reactor trip. Steam generators are being fed by the main feedwater system and decay heat is being removed through the steam bypass system to the main condensers. There is no primary to secondary leakage and no safety relief valves lifted. Site electrical power sources are being fed from off-site power and both units are in a normal shutdown configuration. The emergency diesel-generators are in standby/operable status and were not required during the event. Both units are stable (NOT/NOP) and in Mode 3. The reactor trip response is considered uncomplicated. The licensee has notified the NRC Resident Inspector.
ENS 4706416 July 2011 13:12:00San OnofreNRC Region 4CE

The licensee declared an Unusual Event at 0612 PDT due to entry into EAL HU4.1 for a security-related event. Contact the Headquarters Operations Officer for details. The licensee notified State and local authorities and the NRC Resident Inspector.

  • * * UPDATE FROM DANIEL CRUZ TO DONALD NORWOOD AT 1255 EDT ON 7/16/11 * * *

The licensee exited the Unusual Event at 0950 PDT after verifying that the exit criteria for EAL HU4.1 had been met. Contact the Headquarters Operations Officer for details. The licensee notified State and local authorities and the NRC Resident Inspector. Notified NRR EO (Giitter), R4DO (Cain), IRD MOC (Morris), ILTAB (Allston), DHS SWO (Gates), and FEMA (Via).

  • * * RETRACTION FROM LEE KELLY TO DONALD NORWOOD AT 1356 EDT ON 8/3/11 * * *

After further investigation, the licensee determined that the declaration of the Unusual Event had been a conservative action not required by site procedures. Contact the Headquarters Operations Officer for details. The licensee notified the NRC Resident Inspector. Notified R4DO (Hagar), NRR EO (Thorp), and IRD MOC (Gott).

ENS 4690429 May 2011 16:57:00San OnofreNRC Region 4CEThis notification is for San Onofre Units 2 and 3 and is being made in accordance with 10CFR50.72(b)(2)(xi) to report that on 5/29/2011 at 0957 PDT Government agencies were notified of a sulfuric acid spill. On 5/28/2011 (at) 1440 PDT, during resin bed regeneration operations at the High Flow Makeup Demineralizer (HFMUD), a sulfuric acid transfer was in progress. When process piping was pressurized, a valve on the discharge side of the process pump experienced a diaphragm failure causing a body to bonnet leak. Operators secured the acid transfer. All the sulfuric acid was contained within the bermed area of the HFMUD. Hazardous material teams have contained and cleaned up the spill. Area is secured until repairs can be implemented. All HFMUD operations have been stopped until repairs are completed. On 5/29/2011 at 0926, the hazardous material team determined that this event was reportable to government agencies. The following reports were made: (At) 0957 PDT San Diego Department of Enviornmental Health (was) called with (a) voice message left. (At) 0959 PDT California Emergency Management Agency (was) called. Report number 11-3246. (At) 1008 PDT National Response Center (was) called. Report number 977718. The licensee has notified the NRC Resident Inspector,
ENS 4688224 May 2011 15:20:00San OnofreNRC Region 4CEA maintenance supervisor had a confirmed positive for alcohol during a for cause fitness-for-duty test. The employee's access has been revoked. Contact the Headquarters Operations Officer for additional details. The licensee has notified the NRC Resident Inspector.
ENS 4675514 April 2011 19:35:00San OnofreNRC Region 4CEDuring a scheduled delivery of Hydrogen to Unit 2's active and reserve hydrogen banks, a hydrogen leak was detected at the hydrogen fill connection isolation valve. A notification was made for an uncontrolled release of hazardous material to San Diego Department of Environmental Health at 12:35 PST and California Emergency Management Agency at 12:40 PST. Upon detection, the leak was isolated. The licensee has notified the NRC Resident Inspector.
ENS 4671130 March 2011 14:00:00San OnofreNRC Region 4CECity of San Clemente inadvertently secured power to 19 Community Alert Sirens. Trouble alarms were received at 0700 (PDT) but it is not known at what time specifically power was removed. All sirens were functional the day before when an inspection was performed on 3/29/2011 at 1213 (PDT). Power was restored to the sirens at 1145 (PDT) 3/30/2011. This event resulted in 20 community sirens being non-functional for greater than 1 hour. Siren State Parks 4 (SP-4) was also non-functional for unrelated reasons and remains out of service. Power was restored and all but the state park siren capabilities were declared operable. The licensee notified the NRC Resident Inspector.
ENS 4662117 February 2011 23:11:00San OnofreNRC Region 4CEOn February 17, 2011, at approximately 1200 PST, noted approximately 70 gallons of diluted 35% hydrazine had spilled fully contained in a bermed area from a chemical holding tank inside the Protected Area and subsequently removed to barrels. Off-site notifications were made as follows: National Response Center at 1536 (PST) (NRC REPORT #967808) Cal-EMA at 1530 (PST) San Diego Department of Health at 1526 (PST) The licensee has notified the NRC Resident Inspector.
ENS 4661615 February 2011 19:40:00San OnofreNRC Region 4CEOn February 15, 2011, at about 0830 PST, approximately 65 gallons (calculated maximum of 98 gallons) of partially treated sewage spilled on the ground and into a concrete ditch at San Onofre Nuclear Generating Station (SONGS) at the Mesa area while cleaning up from the plant overflow on 2-11-11. The spill was contained, vacuumed up, and returned to the sewage treatment plant. At approximately 1140 PST, Southern California Edison notified the San Diego Regional Water Quality Control Board, and the San Diego County Department of Environmental Health was notified at 1220 PST. Unit 2 is operating at approximately 100% power and Unit 3 is in Mode 3 after a steam generator replacement and refueling outage. The licensee will notify the Resident Inspector.
ENS 4661212 February 2011 00:15:00San OnofreNRC Region 4CEThe site Environmental Protection (EP) group notified the control room of a 3000 gallon sewage spill from the Mesa Sewage Treatment Plant. The spill overflowed to the storm water catch basin. The EP group notified the San Diego Regional Water Quality Board and the San Diego Department of Environmental Health. All sewage has been contained within the storm water catch basin. EP is currently on station to remediate the sewage spill. No sewage has been discharged offsite. The licensee has notified the NRC Resident Inspector.
ENS 4655018 January 2011 17:45:00San OnofreNRC Region 4CE

On January 18, 2011, at about 0830 PST, a State Park Ranger notified SONGS (San Onofre Nuclear Generating Station) Security that a siren growl was heard in the San Clemente State Park. Security subsequently notified the Control Room. Site Emergency Planning initiated an investigation of the event and informed the City of San Clemente Emergency Planning at approximately 0945 PST of the park ranger's call. SONGS investigation by its siren technicians into the potential SONGS siren growl resulted in absolutely no indication of activation of any of SONGS emergency sirens. It should be noted that quarterly growl tests have been scheduled during working hours January 18-20, 2011, and this information is posted on the City of San Clemente web site. However the tests had not been initiated at the time of the ranger report. In compliance with 10CFR50.72(b)(2)(xi), requiring licensees to report any event that results in notification to other government agencies, SCE (Southern California Edison) is providing this notification to the NRC. At the time of the State Park Ranger notification, Unit 2 was at approximately 100 percent power and Unit 3 was shutdown for a Steam Generator Replacement Outage. SCE will notify the NRC Resident Inspectors about this occurrence and will provide them with a copy of this report.

  • * * UPDATE FROM DENNIS MORRIS TO JOE O'HARA AT 1954 ON 1/18/11 * * *

SONGS telecommunications confirmed that the siren which was reported earlier was associated with Camp Pendleton and not associated with SONGS. Notified R4DO(O'Keefe)

ENS 4650322 December 2010 03:32:00San OnofreNRC Region 4CENotified by the Security Shift Commander at 1932 (PST) that access to the primary EOF is not possible due to flooding. San Onofre will activate the alternate EOF if an event is declared. There are no other affected systems or loss to emergency response capabilities due to this flooding. Access to the site has not been impacted due to the flooding. The NRC Resident Inspector has been notified. See similar report #46499.
ENS 4649921 December 2010 04:20:00San OnofreNRC Region 4CENotified by the Security Shift Commander at 2020 (PST) that access to the primary EOF is not possible due to flooding. San Onofre will activate the alternate EOF if an event is declared. There are no other affected systems or loss to emergency response capabilities due to this flooding. Access to the site has not been impacted due to the flooding. The NRC Resident Inspector has been notified.
ENS 463954 November 2010 22:04:00San OnofreNRC Region 4CE

On November 4, 2010, at approximately 1504 PDT, San Onofre Nuclear Generating Station (SONGS) was notified that scrap circuit breakers salvaged from the SONGS warehouse had alarmed a portal radiation monitor at a metal recycling facility in Los Angeles County. The monitor indicated a reading approximately 40% above background levels. Naturally occurring isotopes in the circuit breakers are suspected to have alarmed the portal monitor. The metal recycling vendor (Alpert and Alpert) called the Los Angeles branch of the California Department of Health Services, Radiologic Health Branch to obtain a special permit authorizing the return shipment to SCE. SCE is reporting this event in accordance with 10CFR50.72(b)(2)(xi). At the time of this report, Unit 2 was operating at 100% power and Unit 3 is defueled. The licensee notified the NRC Resident Inspector.

  • * * UPDATE AT 0018 EDT ON 11/06/10 FROM SIMMON TO HUFFMAN * *

On November 5, 2010, employees of the San Onofre staff disassembled the scrap circuit breakers that had been sent from the San Onofre Warehouse to the Alpert and Alpert salvage yard on November 4. These high voltage circuit breakers contain arc chutes consisting of large ceramic plates that contain naturally occurring radioactive material. All ceramic materials were removed. Health Physics technicians then re-surveyed the circuit breaker casings by direct and indirect survey and verified that they did not contain any detectable levels of radioactive material. Indirect survey of the ceramic material demonstrated that they had no detectable levels of removable radioactive material. The California Department of Health Services, Radiologic Health Branch will be notified of these results. The licensee has notified the NRC Resident Inspector. R4DO (Howell) and FSME (Chang) notified.

ENS 4634619 October 2010 22:15:00San OnofreNRC Region 4CE

On October 19, 2010, at about 1515 PDT, SONGS Unit 3 RPS channels 'B' and 'D' were tested for maintenance. During this testing, both channels were powered off, which brought in LPD/DNBR (local power density/departure from nucleate boiling) trips on both channels. There are no applicable Technical Specifications required for these RPS channels in Mode 5. Southern California Edison(SCE) is reporting this occurrence as a valid actuation of RPS in accordance with 10 CFR 50.72(b)(3)(iv)(a). SCE has taken actions to restore both channels 'B' and 'D' of RPS and cleared the RPS trip signal. At the time of this occurrence, Unit 2 was at approximately 100% power and Unit 3 was in a Steam Generator Replacement Outage, Mode 5, shutdown and cooldown with the RCS open, proceeding to Mode 6." The NRC Resident Inspector has been notified.

* * * RETRACTION FROM DENNIS MORRIS TO PETE SNYDER AT 0045 EDT ON 10/21/10 * * * 

On October 19, 2010, SCE reported (Event No. 46346) a valid actuation of the Reactor Protection System (RPS) in accordance with 10 CFR 50.72(b)(3)(iv)(A). Upon further review, SCE determined the actuation was invalid and is retracting the notification. Maintenance and surveillance testing was being conducted by Computer Technicians on the Core Protection Calculator (CPC) Channels 'A' and 'D', respectively, following station procedures. De-energizing the CPC channels was expected to bring in an RPS trip signal. The process to disable the control room RPS alarms had not as yet, been completed by the Instrument and Controls group when the CPCs were de-energized by procedure, actuating the RPS logic and causing the control room alarms. The actuation is considered invalid, as the equipment that would have been actuated by the trip safety function was previously de-energized and removed from service for the refueling outage. The Unit 3 reactor was in Mode 5, with the reactor trip breakers open, and control rods inserted. Unit 2 reactor remains at 100% power. The licensee notified the NRC Resident Inspector. Notified R4DO (V.Campbell).

ENS 4618217 August 2010 10:00:00San OnofreNRC Region 4CE

On August 16, 2010, at about 0100 PDT, SONGS Unit 2 Train 'A' Emergency Diesel Generator (EDG) 2G002 was removed from service for planned maintenance. Train 'A' EDG is the Appendix R protected Train. At about 1545 the same day, Southern California Edison (SCE) discovered a potential wiring discrepancy in the electronic governor. At 0300 on August 17, 2010, SCE determined two wires on a fire isolation fuse were confirmed to be terminated differently than specified in plant drawings and that the discrepancy would prevent the fuse and associated fire isolation switch from performing its Appendix R fire isolation function for the Train 'A' EDG. In accordance with NUREG-1022, Rev. 2, SCE is reporting this occurrence in accordance 10CFR50.72(b)(3)(ii)(B). While the incorrect wiring impacted the Appendix R qualifications of the Train 'A' EDG, it did not impact its other design functions and the EDG was capable to fulfill its safety function for all other Design Basis Events. Therefore, SCE considers the safety significance of the condition to be minimal. In accordance with LCS specification 3.7.113.1 Condition A, SCE will implement hourly Fire Watches for the impacted plant areas until such time that the wiring on the Unit 3 Train 'A' Emergency Diesel Generator 3G002 is conformed to be correct or has taken actions to correct any wiring discrepancy. An evaluation will be conducted to determine the cause of this condition. At the time of this occurrence, Unit 2 and Unit 3 were both at 100% power." The NRC Resident Inspector will be notified of this occurrence and will be provided with a copy of this report.

  • * * RETRACTION FROM KELMENSON TO KLCO ON 9/14/10 @ 1528 (EDT)* * *

The licensee is retracting the event based on the following: Upon further investigation, SCE determined the suspected wiring discrepancy was only an issue with an elementary diagram that was used for circuit verification. SCE had already flagged this elementary diagram as requiring revision and a change to the diagram was pending and had not been released to the field. The fire isolation fuse was wired correctly." Consequently, SCE is retracting the 8-Hour Telephone Notification made to the NRC on August 17, 2010 (Event Log No. 46182)." The NRC Resident Inspector will be notified of and will be provided with a copy of this retraction. Notified the R4DO (Clark)

ENS 4613328 July 2010 16:45:00San OnofreNRC Region 4CEOn Wednesday, July 28, 2010, at about 0945 PDT, Southern California Edison (SCE) determined that a spill of a total of about 110 gallons of sulfuric acid had occurred from two different locations earlier in the same day. All the acid was contained within the chemical berms around the acid transfer pumps in the Unit 3 intake area at the 9 foot level and the 30 foot level caustic berm. No acid was released to the environment. At 1050 PDT, SCE initiated notification to the San Diego County Department of Environmental Health (Report # 10-063463), the California Emergency Management Agency (CalEMA) (Report # 10-4518) and the National Response Center (Report # 949176). Notifications were completed by 1100 PDT. SCE is making this notification in accordance with 10CFR50.72(b)(2)(xi). The NRC Senior Resident Inspector has been notified.
ENS 4604725 June 2010 21:27:00San OnofreNRC Region 4CEOn Friday, June 25, 2010, at about 1235 PDT, Southern California Edison (SCE) spilled about 25 gallons of Ethanolamine (ETA) while filling the ETA bins from the ETA bulk container. The spill occurred at the SONGS MESA Hazmat pad. Approximately 23 gallons remained inside the hazmat berm; approximately 2 gallons were spilled and contained outside the berm. The SONGS Hazardous Materials personnel are in the process of removing the ETA for disposal. ETA is used to control secondary side chemistry. SCE completed notification of the San Diego County Department of Environmental Health, the California Emergency Management Agency (CalEMA) and the National Response Center (Incident # 945486) by 1427 PDT. SCE is making this notification in accordance with 10CFR50.72(b)(2)(xi). At the time of this report, SONGS Units 2 and 3 are at 100% power. The NRC Senior Resident Inspector has been notified of this occurrence and will be provided with a copy of this report.
ENS 4594321 May 2010 20:20:00San OnofreNRC Region 4CEOn May 19, 2010, at approximately 1730 PDT, San Onofre Nuclear Generating Station (SONGS) was notified that scrap bushings from breakers in the Unit 2 switchyard had alarmed a radiation monitor at a metal recycling facility in Los Angeles County. The metal recycling vendor (Alpert and Alpert) shipped the bushings back to a Southern California Edison (SCE) facility in Orange County. On May 21, 2010, SONGS completed isotopic analysis of a sample of ceramic shards from six randomly selected bushings. The analysis confirms the presence of naturally occurring radionuclides (uranium and thorium series), but does not indicate the presence of licensed radioactive material. On May 21, 2010, at approximately 1320 PDT, SONGS confirmed that on May 19, 2010, the metal recycling vendor had called the Brea branch of the California Department of Public Health, Radiologic Health Branch (Andrew Taylor) to obtain a special permit authorizing the return shipment to SCE. SONGS is, therefore, reporting this event in accordance with 10CFR50.72(b)(2)(xi) as an event related to the health and safety of the public for which notification to another government agency has been made. At the time of this report, both Unit 2 and Unit 3 were operating at 100 percent power. The NRC Senior Resident Inspector has been notified of this occurrence and will be provided with a copy of this report.
ENS 4586020 April 2010 18:03:00San OnofreNRC Region 4CEAt about 0755 (PDT) on April 20, 2010, approximately 200 gallons of sodium hydroxide (caustic) was released into the SONGS Caustic Skid Berm. The release was fully contained within the bermed area and there was no release to the environment. The release is believed to have occurred from a Unit 2 caustic pump pressure safety valve (PSV) during the performance of condensate polishing demineralizer regeneration. The release has been secured and SONGS personnel have pumped the caustic to poly drums. Between 1103 and 1125 (PDT) SONGS notified the San Diego Department of Environmental Health (DEH), the State of California Emergency Management Agency (CalEMA), and the National Response Center of the contained non-radioactive caustic spill within the protected area of the facility. Therefore, Southern California Edison is reporting this occurrence to the Nuclear Regulatory Commission in accordance with 10 CFR 50.72(b)(2)(xi). SONGS Unit 2 is in Mode 1 at approximately 98% power and Unit 3 is in Mode 1 at approximately 50% power. The NRC Resident Inspector will be notified of this occurrence and will be provided a copy of this report. Additional information regarding this event will be provided to one of the Resident Inspectors at the site.
ENS 458104 April 2010 22:42:00San OnofreNRC Region 4CE
Westinghouse PWR 3-Loop

Seismic Recording System activation with ground motion readily felt by control room personnel. Plant inspections performed to date show no observable damage to systems or structures." The seismic event was reported by U.S. Geological Survey as a magnitude 7.2 event occurring 26 km (16 miles) SW of Guadalupe Victoria, Baja California, Mexico. Initial ground motion analysis on site indicated 0.027 g acceleration in the transverse direction. The licensee has notified the NRC Resident Inspector.

  • * * UPDATE FROM ROBERT MEYERS TO DONG PARK AT 2055 EDT ON 4/4/2010 * * *

The Notification of Unusual Event classification was terminated at 1725 PDT on 4/4/2010 after completion of walk downs with no equipment issues being found. Notified R4DO (Okeefe), NRR EO (Bahadur), IRD (Gott), DHS (Vestal), and FEMA (Via).

ENS 457518 March 2010 18:25:00San OnofreNRC Region 4CEA non-licensed employee supervisor had a confirmed positive for alcohol during a follow-up fitness-for-duty test. The employee's access to the plant has been terminated. Contact the Headquarters Operations Officer for additional details.
ENS 4571421 February 2010 16:00:00San OnofreNRC Region 4CE

Southern California Edison has planned work scheduled for the San Onofre Emergency Operations Facility (EOF), for Sunday, February 21, 2010. The work is being done in order to replace a faulty circuit breaker and will result in area lighting being out in the building from approximately 0800 through 1600. During the time that the lighting is out, the EOF will be considered non-functional. Should conditions occur that would merit activation, EOF responders would be directed to the alternate EOF located in Irvine, CA. This planned EOF outage is being reported in accordance with 10 CFR 50.72(b)(3)(xiii). The licensee has notified the NRC Resident Inspector.

  • * * UPDATE FROM TOM SIMMONS TO DONG PARK AT 2042 EST ON 2/21/2010 * * *

Follow up phone call to one made on 2/19/10 regarding planned power outage at normal EOF. Commenced 1145 (PST) today (2/21); restored 1715 (PST). The licensee will notify the NRC Resident Inspector. Notified R4DO (Miller)

ENS 456848 February 2010 08:10:00San OnofreNRC Region 4CEEmergency offsite siren, SC-11, in the City of San Clemente inadvertently activated for (approximately) 20 seconds. (Similar to 1/19/10 event) (EN #45636) Notification of California Office of Emergency Services and FEMA may occur. The licensee is investigating the cause of the alarm. The licensee has informed the NRC Resident Inspector.
ENS 4563619 January 2010 12:30:00San OnofreNRC Region 4CE

On January 19, 2010, at about 0445 PST, the SONGS Control Room was notified of a spurious actuation of a SONGS emergency response siren located in the city of San Clemente. The actuation occurred on January 19, 2010 at about 0430 PST for a duration of approximately 30 minutes. Upon investigation the siren was put into a silent test mode and technicians were able to duplicate the sounding. The siren was subsequently put into an inoperable status pending investigation and the cause of the actuation is unknown at this time. SCE (Southern California Edison) personnel notified Orange County, the City of San Clemente and the City of Dana Point regarding the inadvertent actuation of part of the public notification system.

In compliance with 10CFR50.72(b)(2)(xi), requiring licensees to report any event that results in notification to other government agencies, SCE is providing this notification to the NRC. At the time of this occurrence, Unit 2 was shutdown for a Steam Generator Replacement Outage and Unit 3 was operating at about 100 percent power. SCE will notify the NRC Resident Inspectors about this occurrence and will provide them with a copy of this report.

ENS 4563419 January 2010 03:50:00San OnofreNRC Region 4CE

On January 18, 2010, at about 1950 PST, the access road to the SONGS MESA facilities became flooded after a day of rain. The San Onofre Emergency Operations Facility (EOF) is located at the MESA and because of the flooding, is inaccessible to passenger vehicles. While the EOF itself is operable, in the event of an emergency at San Onofre, SCE (Southern California Edison) would direct EOF emergency responders to the alternate EOF located in Irvine, California. SCE is reporting this occurrence to the NRC in accordance with 10CFR50.72(b)(3)(xiii). At the time of this occurrence, Unit 2 was shutdown for a Steam Generator Replacement outage and Unit 3 was operating at about 100% power. SCE will notify the NRC Resident Inspectors about this occurrence and will provide them with a copy of this report.

  • * * UPDATE FROM GEOFF COOK TO DONG PARK @ 1208 EST ON 01/19/10 * * *

On January 18, 2010 at about 2101 PST, the MESA road flooding had dissipated sufficiently for car traffic to be passable. In the event of an emergency at San Onofre, there is no longer a need to redirect emergency responders to the alternate EOF located in Irvine, California. This report is to advise the NRC of this change in EOF access status. Also note that it is expected that rain will continue in the SONGS area during the week of January 17, 2010 and this status is subject to change. At the time of this occurrence, Unit 2 was shutdown for a Steam Generator Replacement Outage and Unit 3 was operating at about 100% power. SCE will notify the NRC Resident Inspectors about this occurrence and will provide them with a copy of this report. Notified R4DO (Werner) and NSIR (Kahler).

  • * * UPDATE FROM GEOFF COOK TO PETE SNYDER @ 1232 EST ON 01/21/10 * * *

On January 20, 2009, at about 2107 PST, the access road to the SONGS MESA facilities again became flooded after a day of rain (reference NRC Operations Log Number 45634). The San Onofre Emergency Operations Facility (EOF) is located at the MESA and because of the flooding, is inaccessible to passenger vehicles. While the EOF itself is operable, in the event of an Emergency at San Onofre, SCE would direct EOF emergency responders to the alternate EOF located in Irvine California. SCE is reporting this occurrence to the NRC in accordance with 10CFR50.72(b)(3)(xiii). At the time of this occurrence, Unit 2 was in a Steam Generator Replacement Outage and Unit 3 was operating at about 100% power. SCE will notify the NRC resident inspectors about this occurrence and will provide them with a copy of this report." Notified R4DO (Werner) and NSIR/EP.

ENS 4562813 January 2010 19:25:00San OnofreNRC Region 4CE

On January 13, 2010, at about 1125 PST, Train A suction piping from the SONGS Unit 3 Refueling Water Storage Tank (RWST) was determined to be inoperable following detection of weld flaw indications during ultrasonic testing. Due to miscommunication, operators mistakenly declared the Train B Emergency Core Cooling System (ECCS) header inoperable at about 1125 and removed DC control power to the Train B ECCS pumps. This resulted in both trains of Unit 3 ECCS being inoperable and entry into the Technical Specification (TS) 3.0.3 one-hour shut down action. At 1140 PST, the DC control power was restored to the Train B ECCS pumps, Train B ECCS was declared operable, and TS 3.0.3 was exited. SCE is reporting this in accordance with 10 CFR 50.72(b)(3)(v) as an event that could have prevented the fulfillment of a safety function. SCE is further evaluating the indications found on Train A piping to determine if the piping is capable of performing its safety function. At the time of this occurrence, Unit 2 was in a Steam Generator Replacement Outage, and Unit 3 was at approximately 100% power. The licensee notified the NRC Resident Inspector.

  • * * RETRACTION PROVIDED BY LEE KELLY TO DONG PARK AT 1402 EST ON 1/19/10 * * *

On January 13, 2010, SCE reported that both trains of Unit 3 Emergency Core Cooling System were inoperable for approximately 15 minutes because Train B ECCS was mistakenly taken out of service when weld flaw indications were found on Train A ECCS piping. This resulted in a condition that could have prevented the fulfillment of a safety function. Consequently, both trains of ECCS in Unit 3 were declared inoperable and the unit entered into Technical Specification 3.0.3 at 1134 PST (Time of Discovery). At 1140 PST, Train B ECCS was declared operable and TS 3.0.3 was exited. Event Notification 45628 was conservatively made because, although Train A ECCS piping remained capable of performing its safety function, this was not yet formally documented at the time the 8-hour report was due. Subsequently, an engineering evaluation was completed at 2308 PST on January 13, 2010, that demonstrates the as-found condition of the Train A ECCS piping was operable because the flaw meets the evaluation criteria of ASME Boiler and Pressure Vessel Code Case N-513-2. Since Train A ECCS piping was operable, this event did not constitute a condition that could have prevented the fulfillment of a safety function and is not reportable under 10 CFR 50.72(b)(3)(v)(D). Consequently, SCE is retracting the phone report to the NRC on January 13, 2010. The NRC Resident Inspector will be informed of this report. Notified R4DO (Werner).

ENS 4561623 December 2009 18:14:00San OnofreNRC Region 4CEThis is a late eight hour report submitted under 10CFR50.72(b)(3)(v), 'Loss of Safety Function to (B) Remove Residual Heat' On December 23, 2009 at about 0957 PST, with SONGS Unit 2 defueled for the Cycle 16 refueling outage, a decrease in salt water cooling flow to the Train A Component Cooling Water Heat Exchanger indicated debris was entering the system. The loss of flow appears to have been caused by debris entering the system through a failed pump suction screen. At 1014 PST operators removed the heat exchanger from service for approximately one hour to reverse the salt water cooling flow though the heat exchanger and clear the debris. The Train B cooling system had previously been removed from service for scheduled maintenance, relying on the single Train A heat exchanger to supply cooling to the Spent Fuel Pool cooling system. Salt water cooling flow was fully restored at approximately 1118 PST. Operators conservatively declared the Spent Fuel Pool Cooling System inoperable and maintained compliance with the conditions of Licensee Controlled Specification 3.7.106. Time to exceed the 160 degree Fahrenheit allowable pool temperature was estimated at over twenty three hours. It has been determined that the temporary isolation of the heat sink from the spent fuel pool constituted a loss of safety function for residual heat removal. Therefore SCE is reporting this occurrence as a loss of safety function in accordance with 10 CFR 50.72(b)(3)(v). The safety significance of this event was minimal. Flow reversal to clear ocean debris from the heat exchangers is a routine procedurally controlled evolution and bounded by design calculations which consider post-accident heat loads with a full core offload in the spent fuel pool. These actions are within the limits of both the Technical Specifications and Licensee Controlled Specifications. The licensee will inform the NRC Resident Inspector.