The Wolf Creek nuclear power plant sits on the flat plains of Kansas about 60 miles south of Topeka and 4 miles from Burlington, about 200 miles east of the wheat fields I farmed as a kid. A 5,090-acre lake filled with crappie, walleye, large and smallmouth bass, and other game fish provides cooling water for the reactor and also provides a fishing mecca for Kansans. The 10,500-acre site, including the reactor complex and the lake, has about 1,500 acres of wildlife habitat, and about one-third is leased to area farmers and ranchers. The plant itself takes up less than half a square mile. The lake provides habitat for waterfowl, as well as for bald eagles and osprey. It is hard to imagine that electricity for 800,000 people is generated in this pristine area of farmland and nature preserve.

Security was tight when I visited the plant. At the security checkpoint my car was scrutinized with mirrors to look underneath and scanners to detect anything hazardous being brought onto the site. After passing through the gate and an active vehicle barrier with a guard presiding, I drove to the Security Building. After meet­ing Tom Moreau, my tour guide who is a radiation specialist originally trained in the Navy for nuclear submarines, I gave my identification and went through the security entrance, similar to that for an airport, with an air puffer to detect any chemical residue from explosives, picked up my visitor identification badge, and was let through a locked security gate. I was then in the plant and was not allowed to ever leave the side of my guide. This entire area is surrounded by razor wire and is constantly observed by cameras and guards with machine guns in guard towers.

Earplugs were handed out before we entered the turbine building and I soon found out why. This building houses the enormous feedwater pumps, condens­ers, high — and low-pressure turbines, and the main generator that produces 1,200 megawatts at 25,000 volts that goes to step-down transformers and into the elec­trical grid. It is very clean but very noisy, hence the earplugs. This building is essentially the same that one would find in a coal-fired plant or a gas-fired plant (see Chapter 3); the only essential difference is the source of heat to make the steam to drive the turbines and the generator.

Entering the Radiation Control Area required activating doors using both my badge and Tom’s badge. This area is the heart of the reactor plant, and all who enter must have documentation and prior approval. Computer screens in this area observe radiation monitors throughout the reactor containment and aux­iliary building. We were given radiation badges and took off our earplugs, then went through other secure doors to the containment building which consists of reinforced concrete 3 feet thick, lined with a leak-tight carbon steel barrier (see Figure 5.1). This building, 208 feet high by 140 feet in diameter, houses the reactor vessel, which is 44 feet high and 14 feet in diameter with special alloy steel walls 5.4 to 6.8 inches thick.

Inside the reactor vessel is the actual reactor with the fuel elements and control rods. The fuel elements are uranium fuel pellets the size of a pencil eraser stacked into 12-foot long fuel rods, which are bundled into fuel assemblies containing 264 fuel rods. The reactor contains 193 fuel assemblies. The water circulating through

Typical Pressurized-Water Reactor

the reactor is heated to 585°F at 2,200 pounds per square inch. Because the high pressure prevents the water from boiling, this type of reactor is known as a pres­surized water reactor, the most common type of reactor in the United States and the world. This water in the primary loop circulates through the four steam gen­erators, which form the secondary loop, all within the containment building. No water in the primary loop is in contact with the water in the secondary loop, so no radiation can be picked up by the steam that drives the turbines. The steam is then transferred to the turbine building, where it produces electricity.2 This area by the containment building is completely quiet, in contrast to the turbine building.

The reactor had just been refueled about a month before I was there, and I was curious to see the used fuel assemblies, which are highly radioactive and physi­cally hot. After going through additional security doors, we entered the spent fuel pool area, which is a concrete tank filled with boronated water to absorb neutrons. The pool is surprisingly small, only about the size of a ranch house. The blue water
is extremely clear, and it is impossible to sense the radiation emanating from the spent fuel. If you are lucky, you can see the blue Cherenkov radiation emitted by electrons traveling faster than the speed of light in water, but I was unlucky. You can see a matrix of the long, slender fuel assemblies under the water.

After leaving the reactor spent fuel pool, Tom and I had to be checked for any radiation picked up on our tour. When I put my hand in the sleeve of the radia­tion monitor and stood there, the red light blinked, indicating that I had too much radiation. It turned out, as it usually does, that the hardhat—which is plastic—gets static electricity and attracts charged daughter products from radon decay, which is emanating from the spent fuel pool. After removing my hardhat, I got a green light, indicating that I was free of radiation. My radiation badge indicated that I got zero mrem3 after touring the reactor plant. It is no more dangerous to be in a nuclear power plant than in any other type of power plant. Workers in the plant are allowed a maximum of 500 mrem (5 mSv) per year, but it is extremely rare for any worker to approach that level. The average exposure of workers in nuclear power plants that received a measurable dose of radiation was only 100 mrem (1 mSv), less than a third of average natural background radiation (4).