San Onofre Nuclear Generating Station - Democratic Underground

wtmusic

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Tue Apr-06-10 06:35 PM
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San Onofre Nuclear Generating Station

Edited on Tue Apr-06-10 06:36 PM by wtmusic

I took my kids for a tour of San Onofre Nuclear Generating Station today, and brought along a friend who's an environmental engineer working on solid waste gasification technologies.

After 9/11 the public isn't allowed onsite - they conduct the tour at the training facility on the other side of the 5 freeway. I had to make reservations months in advance, providing name and citizenship, and security was tight. As you can see in the third photo (from left), we nearly had the tour to ourselves.

The tour starts with a 1-1/2 hour overview of the history and operation of the plant, going into basic principles of nuclear fission and reactor design. At San Onofre there are two traditional HPWRs (high-pressure water reactors), which use closed loops of water at 2200 psi and 595°F to pull heat from the reactor cores. Each loop conducts thermal energy to a steam generator, which drives the turbines. At full capacity (most efficient) each reactor generates 1,100 MWe.

Afterwards, the tour went around the building to view the various classrooms where employees are taught how to run a nuke plant. There is a shortage of qualified operators, so Southern California Edison trains from within and pays well (if you're one of the six people in the reactor control room you're making about $150K). Finally, we viewed a control room simulator which is an exact mockup of the actual room. A senior employee tests trainees by throwing simulated "events" at them from a side room computer console and evaluating their response.

They seem obsessive about safety, and I was surprised at the number of times Three Mile Island came up. Although someone in our tour asked about Chernobyl, they dismissed it as a terrible design which doesn't exist anymore, run by poorly trained people. Interestingly, however, we learned that Chernobyl unit #4 continued to provide power until 2000 (I hope the Russians pay their reactor operators even more). Three Mile Island hit close to home because it is a similar design, and they were constantly describing how this or that was "a lesson we learned from TMI." There are four levels of safety alerts at San Onofre, and the plant has never gotten past a Stage 1. I asked our guide how much radiation he has been exposed to during his 26 years at the plant. He claims that his total exposure has been less than 1,000 millirem (about that of a CAT scan), and his worst year was 100 millirem.

Like all other American power reactors, waste is stored on-site. It's kept in pools of water next to the reactors for 7 years until it cools down, then in dry cask storage.

Below, on the far right, is a little tsotchke they gave us - a plastic cylinder the size of a uranium fuel pellet (note dime for scale). The energy each pellet provides is equivalent to that from 149 gallons of oil, one ton of coal, or 17,000 ft³ of natural gas.