BeigeJournal

I saw on Dave Slusher’s blog a link to Charlie Stross’ web site, where I found his article about a tour of the Torness nuclear reactor complex. Since I’ve been so fortunate as to get a tour of a nuclear power plant myself I had to point to his article and thought I’d write a bit about my own tour.

I visited the Clinton Power Station in central Illinois, back then in roughly 1994 still owned by Illinois Power. I was taking a radiation protection course at the University of Illinois at Urbana-Champaign and since our professor also worked at the plant an the head radiation safety person he was able to arrange the tour for us. Even in those days this involved some sort of FBI background check on us beforehand.

The Clinton plant is a 950 MWe boiling water reactor located, naturally, near Clinton, Illinois. These plants are amazing things to see. Giant buildings, huge pipes, meters-thick reinforced concrete walls, and tremendous bundles of wires, tubes, lines, pipes, and cable running every which way.

We visited the top level in the containment building. One passes through an air lock to get into containment. The air lock doors at Clinton are cranked open and shut with big handwheels. It’s a fairly dull place considering that we were within 20 meters or so of a reactor operating at around 3 gigawatts thermal. Looking down around the edges the suppression pools where steam is dumped during certain sorts of emergencies can be seen. Apparently one would prefer to not be in there on the rare occasions when that happens. There’s a polar crane in the cylindrical containment building for use during refueling. Wrapped up in plastic was the powerful hydraulic device used to remove and re-attach the very large nuts that hold the pressure vessel lid on.

The turbines are hidden behind a wall in a BWR, since the steam is a bit radioactive even under normal conditions. We were able to see the tops of the turbines over the wall from an upper level at the other side of the turbine building. I’ve seen some large generators before, but the 950 megawatt unit basically took the form of a large building located inside the much larger building housing all the machinery that is outside the containment.

Rather than see the actual control room we toured the simulator, which is on-site. The simulator staff was eager to show off things that are basically incomprehensible to people who are not reactor operators. They’d press some buttons and proudly announce that this is what a design-basis accident would look like. What it looks like is every warning light in the control room, and there are an awe-inspiring number of warning lights, lights up. All at once. I imagine that operators have dreams that look like that.

One thing that was really quite interesting to actually see was the spent fuel pool. There’s not actually much to see, but the size is interesting. The pool there is sized to hold twenty years worth of spent fuel. Twenty years is a long time, yet the pool really isn’t very big, especially considering the giant scale of everything else there. Spent fuel is extremely hazardous but the quantity produced is remarkably small.