Calif. Utility Retreats on Nuke-Monitor Capability
The utility that runs California's idled San Onofre nuclear power plant backpedaled Tuesday from an earlier claim that a retooled vibration-detection system for the plant's ailing steam generators would be an important safety advance that could help open the way for a possible restart.
Southern California Edison said in its October proposal to restart the Unit 2 reactor that the redesigned system, which relies on monitors to detect unusual vibration inside the huge generators, could help detect a break in a tube that carries radioactive water, according to federal documents.
Excessive tube wear has been at the heart of problems at San Onofre, which hasn't produced electricity since January, after the plant was abruptly shut down after a tube break released a trace of radiation. Investigators later found excessive wear on hundreds of tubes in the virtually new generators.
Edison officials came under sharp questioning about the monitors at a Nuclear Regulatory Commission panel meeting in Maryland, where an NRC official argued that the equipment could not do the job described by the company or provide additional safety if the plant is restarted.
"The instrumentation that you're proposing ... does not appear to be capable of detecting the conditions that would lead to actual tube wear," said Richard Stattel of the agency's instrumentation branch.
The company depicted the equipment in its restart plan as an important safety measure "but it doesn't appear to do that," Stattel said. The NRC staff "doesn't understand where that adds an additional safety margin" as proposed by the company.
Mike Short, an Edison consultant, told regulators that the company "had not intended" to characterize the system as an important safeguard, technically known as "defense-in-depth," or multiple layers of systems designed to prevent accidents or the release of radiation from a nuclear power plant.
Short said the data collected by the system could be used in future research examining vibrations picked up by the monitors. "It's our plan ... to make sure that's clear," he said.
The agency is in the midst of reviewing Edison's plan to rekindle one of two damaged reactors. The company wants to run Unit 2 at reduced power, a change that company engineers believe will reduce vibration that damaged tubes in the Japanese-manufactured generators.
A decision could come as soon as March. Critics of the nuclear industry have depicted twin-domed San Onofre, located between San Diego and Los Angeles, as a catastrophe-in-the-making.
The original monitoring system was at issue in a federal investigation after the plant was shut down in January.
NRC officials sifted through months of data to determine if Edison properly analyzed a series of mysterious vibrations detected inside the now-crippled Unit 3 reactor. Thirty times over 11 months, monitors positioned in the reactor's two steam generators triggered alarms after sensing unusual movements, according to documents and Nuclear Regulatory Commission officials involved in the probe.
At the time, it raised the questions about whether Edison missed possible clues that something was terribly wrong inside the generators. However, the agency later determined that the vibrations were not connected to tube-to-tube wear, according to NRC officials.
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Calif. Utility Retreats on Nuke-Monitor...- The problem here to me at least is obvious. If the new generators are fine but the tubes taking the radiated water and steam are not my question would be: "How many other Nuclear power plants around the U.S. used the same kinds of Tubes?" (That could also be failing).
Even though (as far as I can remember in my lifetime) we haven't even had an 8.0 earthquake in California, we have had 7.0 s or larger both in northern and in Southern California at a frequency of about one every 10 years. A 7.0 within 50 to 100 miles of ANY nuclear power plant likely would be enough to make the area around a nuclear power plant uninhabitable for 100 miles or more in every direction sort of like Chernobyl or Fukushima. Though supposedly all nuclear power plants are built to withstand a Boeing 747 in a direct hit of the plane, the damage done by an earthquake would use all the weight of the cement and piping directly against the nuclear power plant which almost always would cause cracks and would release radiation into the surrounding area. This is likely a given for any nuclear power plant in California at least. This is why San Onofre was the last nuclear power plant that I know of still in operation in California until last January 2012.
And I personally believe the main reason that it was kept running was because except for the city of San Onofre and the relatively near Marine base and housing, San Onofre Nuclear power plant isn't near enough to large sections of heavily populated areas except to the North a ways and then to the South from Oceanside, California. So, because of the distances from larger centers of population I believe it was kept running to power the marine base in case of an emergency or loss of the power grid in some future emergency. So, I think the main reason that San Onofre was kept running was as an emergency backup in case of problems elsewhere in the grid for any reason until January 2012.
The Nixon residence sometimes called "The Western White House" was in San Onofre and if I remember correctly it was built around the time of the Nixon western White house days during the late 1960s and early 1970s.
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