Inside a Nuclear Plant: Skip the Lip Balm
[imgbelt img=CooperHydraulicControl530.jpg]The power tourist, Julianne Couch, clears security, dons a dosimeter and takes us inside a nuclear plant in far east Nebraska.
On a ridge outside the northwest Missouri town of Rock Port, population 1395, four wind turbines generate enough electricity to power the town. If you perched on top of one of those tall towers, you’d be able to see across the Missouri River, and to spot Brownville, Nebraska (pop. 185), home of the Cooper Nuclear Station. The Cooper power plant could light up many, many towns the size of Rock Port: its gross generating capacity is 800 megawatts of electricity. Per hour.
Nuclear plants emit no greenhouse gasses. They take up a less space than fossil-fuel burning power plants require and a teeny, tiny fraction of the space needed for a wind farm producing comparable amounts of electricity. The first commercial nuclear power plant in the U.S., the Shippingsport Reactor in Pennsylvania, began operations over fifty years ago. Today there are 103 nuclear plants in the U.S., most of them east of the Mississippi. Nuclear power has been championed as an efficient and inexpensive source of energy and condemned as a peril to the human health and the environment.
But as the debate over green energy continues to heat up, there’s renewed interest in nuclear power. Could it possibly be “greener” than sprawling wind farms, or coal-fired plant belching CO2?
I decided to look inside one of these mysterious powerhouses, and sought permission to visit Nebraska’s Cooper plant. It’s managed by Entergy for the Nebraska Public Power District (NPPD), and representatives from the company and NPPD offered me a tour.
At the Cooper plant, boiling water makes steam to turn turbines to create electricity, much like other types of plants. But rather than burning coal or some other fossil fuel, Cooper uses enriched uranium fuel to create heat. The elephant in the room, of course, is what one does with the highly radioactive used fuel once its heat-generating capacity is spent.
I arrived at Cooper punctually at 0800, driving past the small state park where Lewis and Clark once camped. I had submitted my Social Security number to Glenn Troester, the plant’s communications coordinator, a few weeks earlier so that I could be cleared to visit. I’d also been given a list of rules before entering the plant and took care to follow them all: no synthetic fibers (they attract radon particles); no shoes with metal shanks (they set off metal detectors); no lip balm (on lips ok, in pocket not ok); photo ID, yes; “knives, ammunition, firearms, fireworks, or anything else that goes pop, zip, buzz, hummm, whirr, zing, hiss or even pffft” – definitely no.
Glenn, Mark and I met in the plant’s Learning Center, where Troester explained how uranium is mined, then enriched for fuel in places such as Paducah, Kentucky. The fuel comes in the form of ceramic pellets. Troester handed me an information card with a plastic bubble window. Inside was a half-inch long simulated fuel pellet. At present, a bundle of uranium costs $645,000. If that pellet had been real uranium, it could create the energy equal to 149 gallons of oil, one ton of coal, or 17,000 cubic feet of natural gas.
[imgcontainer left] [img:cooper-HANDLING-FUEL-320.jpg] [source]Glenn TroeslerA fuel handler at the Cooper plant guides rods containing uranium to the inspection stand.
The real uranium pellets are encased in zirconium tubes, or fuel rods. Around 33,000 of those rods, assembled into 548 fuel bundles, are contained in the reactor. That’s where the U-235 isotope, which fissions readily, joins with the U-238 isotope (basically the “designated driver” in this process). Inside the reactor, these materials bounce and jostle against one another, creating a fission chain-reaction tempered and regulated with water.
Becker and most other observers of nuclear energy believe that the plan to create a central depository for used fuel at Yucca Mountain, Nevada, won’t come to pass. That leaves each plant, for now, pretty much up to its own devices for figuring out how and where to store used fuel.
The first stop on our tour was the Learning Center window, to see the Used Fuel Dry Cask storage area, Cooper’s solution to the storage problem, for now. This man-made reverse mountain of concrete and steel is connected not just to the ground but to the bedrock below. The used fuel in this dry cask must be cooled for at least a year in the used fuel pool. That’s basically a 38-foot deep swimming pool for the extremely hot and highly radioactive fuel rods that have been removed at the end of their lifespan.
Before we could see the pool or other places in the Radioactive Control Area (RCA), we had to pass through security. As you’d hope and expect, security at a nuclear plant is anything but casual. It starts with the approach to the plant and the view of imposing gates topped with razor wire. Guards on watchtowers are armed with military-grade assault rifles. They can pretty much shoot anyone whose actions will threaten the plant or the people in it. More armed guards are stationed on the ground outside and around the control room at the heart of the plant. They aren’t in the RCA area though. (No one should tarry in a radiation area.)
Before entering the Radioactive Control Area, we all signed release forms saying we knew what we were doing; we then went through an airport-style metal detector with our small belongings sliding through an X-Ray machine. Then we headed for what amounted to a reception area at the RCA to pick up our “trip ticket” cards and a direct reading dosimeter, a machine that monitors radiation levels along the tour route. Visitors are required to know what normal radiation levels would be along the tour route, so we filled out the trip tickets affirming that we knew this information before starting the tour.
Signage reminded us of all to be aware of As Low As Reasonably Possible exposure, when it comes to radioactive material. Troester’s goal for his tour charges was an expected gamma ray dose of less than 0.3 millirem (mrem) for the entire tour. Reassuringly, our Expected Contamination Level was 0.