San Onofre nuclear plant in California returns to normal

Perhaps because the words "evacuated" and "San Onofre Nuclear Generating Station" in the same sentence spread panic, the County of Orange is now clarifying that workers were "removed" from two SONGS buildings where non-radioactive ammonia leaked this afternoon, adding "but site evacuations were not necessary." The county emergency center reiterates, "There is no need for the public to evacuate."


Besides the phone book section and website below that people can check for more safety information, the county says its Public Information Hotline is staffed to answer questions at 714.628.7085. Only call 9-1-1 if you have a life-threatening emergency, an updated county alert adds.


The county also suggests keeping tabs of radio and television reports on the SONGS incident.


Workers stopped the leak by 5 p.m. Tuesday, about two hours after it was detected in a storage tank in the water purification system of San Onofre Nuclear Generating Station’s Unit 3, said Todd Adler, the plant’s engineering manager.


The emergency alert was required because fumes could prevent access to certain areas of the plant, Adler told reporters at a media information center in Irvine, Calif.


The alert, the second lowest of four federal classifications for emergencies at commercial nuclear power plants, was canceled at 6:07 p.m. and evacuated workers were allowed to return.


“It’s a chemical spill that could happen at any industrial facility,” Adler said.


The leak was in the non-nuclear section of the plant, which is operated by Southern California Edison. No radioactive material was released, no injuries were reported and there was no danger to the public, the company said.


Approximately 25 gallons of leaked ammonia were collected in a basin underneath the tank that was designed for that purpose, Edison spokeswoman Lauren Bartlett said.


Exposure to high levels of ammonia can cause irritation, serious burns, lung damage, and even death.


It is used at the plant to treat water that is turned into steam, which runs the turbines that produce electricity. The treated water also is used to remove heat from the reactor’s cooling system.


The leak did not affect electricity production at the plant, and other units remained fully operational, Adler said.


The plant is located about 45 miles north of San Diego, just south of San Clemente, and is jointly owned by Edison, San Diego Gas and Electric and the city of Riverside.


While not dangerous for the public or plant workers, an emergency alert at the power plant is an unusual occurrence.


“This is not normal,” Edison spokesman Chris Abel said. “The last time we had one (alert) declared was May 1999, because of a suspected pipe bomb on the freeway.”


In July, an “unusual event” was declared at the nuclear plant when one of several redundant security systems used to monitor the grounds stopped working, utility officials said. The system was restored within 45 minutes.

San Onofre Nuclear Generating Station

San Onofre Nuclear Generating Station (SONGS) is a nuclear power plant located on the Pacific coast of California. The 84-acre (34 ha) site is in the northwestern corner of San Diego County, south of San Clemente, and surrounded by the San Onofre State Park and next to the I-5 Highway.
Unit 1 is no longer in service and has been dismantled. It is being used as a storage site for spent fuel. It had a spherical containment of concrete and steel with the smallest wall being 6 feet (1.8 m) thick. This reactor was a first generation Westinghouse pressurized water reactor that operated for 25 years, closing permanently in 1992. Units 2 and 3, Combustion Engineering pressurized water reactors, continue to operate and generate 1,172 MWe and 1,178 MWe respectively.
The July 12, 1982 edition of Time (magazine) states, "The firm Bechtel was further embarrassed in 1977, when it installed a 420-ton nuclear-reactor vessel backwards" at San Onofre.
The plant is operated by Southern California Edison. Edison International, parent of SCE, holds 78.2% ownership in the plant; San Diego Gas & Electric Company, 20%; and the City of Riverside Utilities Department, 1.8%. The plant employs over 2000 people.
The plant is located in Nuclear Regulatory Commission Region IV.




Surrounding population


The Nuclear Regulatory Commission defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone with a radius of 10 miles (16 km), concerned primarily with exposure to, and inhalation of, airborne radioactive contamination, and an ingestion pathway zone of about 50 miles (80 km), concerned primarily with ingestion of food and liquid contaminated by radioactivity.
The 2010 U.S. population within 10 miles (16 km) of San Onofre was 92,687, an increase of 50.0 percent in a decade, according to an analysis of U.S. Census data for msnbc.com. The 2010 U.S. population within 50 miles (80 km) was 8,460,508, an increase of 14.9 percent since 2000. Cities within 50 miles include San Diego (45 miles to city center).




Environmental mitigation


Strong, spherical containment buildings around the reactors are designed to prevent unexpected releases of radiation. The closest tectonic fault line is the Cristianitos fault, which is considered inactive. Southern California Edison states the station was "built to withstand a 7.0 magnitude earthquake directly under the plant".
Unlike many pressurized water reactors, but like some other seaside facilities in Southern California, the San Onofre plant uses seawater for cooling, and thus lacks the iconic large cooling towers typically associated with nuclear generating stations. However, changes to water-use regulations may require construction of such cooling towers in the future to avoid further direct use of seawater. Limited available land next to the reactor would likely require the towers to be built on the opposite side of the Interstate 5 highway.




Seismic risk


The Nuclear Regulatory Commission's estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at San Onofre was 1 in 58,824, according to an NRC study published in August 2010.




In popular culture


In the James W. Huston book, Fallout, Pakistani Air Force Pilots attempt to bomb San Onofre using stolen California Air National Guard F-16s. In the James Bond book License Renewed by John Gardner, it was one of six nuclear power stations in the terrorist/blackmail plot "Meltdown" planned by The Laird of Murcaldy, Anton Murik. In the science fiction novel Timescape, by Gregory Benford, the nuclear plants at San Onofre raised the water temperature along the adjacent coast, which stimulated aquatic life.
The generating station was also featured in the 1983 film Koyaanisqatsi.
In the 2011 TV series The Event, the fuel rods were removed and transported from San Onofre Nuclear Generation Station to thwart the aliens' plan to steal the uranium to build their specialized transport array. The transport array was utilized to transport the citizens from their own planet to Earth.




Emergency


At approximately 4:10pm on November 1st, 2011, radio station KFI AM 640 reported that there is an emergency at San Onofre nuclear power plant. A level Three nuclear emergency was declared after a leak was spotted in a part of the plant that deals with electricity. It was determined to be an ammonia leak and no health hazards were to be expected.