Before each jump, jumpers go through training sessions on a full-scale model of a steam generator
Deep in the bowels of the nuclear power plant, mere feet from the reactor core, sit the steam generators–areas so radioactive that only specially trained workers are allowed to enter. They’re allowed to stay inside for only a few minutes before exposure to dangerously high levels of radiation threatens their safety. And yet someone must enter in order to install a dam that stops the water from re-entering the generator while repairs and inspections are made.
"Nobody wants that job," said Brett Allen, an instructor at Cuesta College who heads a PG&E training program. "It’s like a lifeguard specializing in 100-foot-wave rescues. You may not live as long." Officially they are known as nozzle dam technicians, but to those in the industry, they are the "jumpers."
The jumpers are hired by contractors like Atlantic Nuclear Services of Norfolk, Virginia or directly by reactor manufacturers which contract repair and maintenance services to more than half of the nation’s utilities.
"We’ve had people from a variety of backgrounds, from college professors to bartenders, work for us," says Melvin Miller, a spokesman for Nuclear Services. "They do it because it pays well. Maybe they make a jump and then have some extra money for a vacation that year, or maybe it helps them through rough times in between jobs." Other jumpers are recruited from the ranks of the construction unions who build the plants when construction work is slow. But the majority are typically people with few job skills and little or no prospects for jobs elsewhere.
Inside Containment, the large dome-shaped building that houses the reactor and four steam generators, the jumpers put on two sets of protective clothing and a hooded bubble suit. Dressed in the plastic yellow suits, the jumpers look primed for outer space. In actuality, they are ready to jump (hence the name) head first through a “manway,” a tight-fitting passage that leads to the generator channel head. The bowl-shaped channel head is a stifling-hot area about half the size of a Volkswagen bus. Within these cramped confines the jumper must assemble the three-piece nozzle dam and install it over a 42-inch diameter pipe that connects to the reactor. All the while the jumper is fully aware that if he goes too fast he may screw up, and if he goes too slow he is increasing his radiation exposure.
The monumental screw-up would be for a jumper to fall in the hole where the nozzle dam is placed–the hole that leads to the reactor. “It’s a long way down there,” said Jo Brasseaux, 39, one of the only female jumpers in the industry. “It’s really, really scary.” If someone were to fall down there, another jumper would have to enter the channel head, reach into the pipe and pull the person out–thus exposing both of them to amounts of radiation nobody wants to talk about. “It’s a possibility, but we don’t think about it,” Brasseaux said. Mike Nielsen, a jumper from Grover Beach, concurs. His attitude is, “If you’re that worried about it, you shouldn’t be here.”
At least one jumper, 21-year-old Jesse Powers, knows firsthand that falling in the hole is not an impossibility. The Central Coast native fell into the pipe during mockup, a training session held before each jump in which they practice for about a week on a full-scale model of a steam generator. According to Powers, at some plants the pipe is situated in such a way that if you slip upon entry into the channel head, “You’re going down there.”
A far more pressing concern, however, is the amount of radiation jumpers are exposed to. Just five minutes in the generator can expose the jumper to 1 rem of radiation, the equivalent of 50 chest X-rays. A rem is the measure of cell-damaging radiation absorbed by the body. “Jumpers get a good dose,” said Nielsen. “We get more than anybody.”Nevertheless, he said it is only the new guys who worry about it. Nielsen, who is 58, used to add to their fright by telling them, “I’ve been doing this three years, and there’s nothing wrong with me. And I’m 25 years old.” Eventually he was told, “Stop that! You’re scaring the kids!”
The seasoned jumpers take comfort in knowing that they are exposed to far less radiation than the limits set by the Nuclear Regulatory Commission (NRC). The NRC limits worker exposure to 5 rem per year, the equivalent of 250 chest X-rays. Most plants limit workers to half that amount. There are those in the scientific community who contend that no amount of radiation is safe. Nuclear Information and Resource Service, an activist organization, puts out a pamphlet called “No Safe Dose.” In it, Dr. Karl Z. Morgan, dubbed the father of health physics, says, “There is no dose of radiation so low that the risk of a malignancy is zero.” An even more insidious risk to jumpers and others working near the generator is internal contamination from radioactive particles. Gary Olson, a former utility worker at Diablo Canyon Power Plant, said that when platform workers remove the manway cover, the sealing services have to be cleaned with a wire wheel before reassembly. As they are cleaned, clouds of radioactive particles can be seen. These particles are particularly dangerous if ingested. While a jumper lessens his radiation exposure the moment he exits the generator, an inhaled particle can become permanently lodged in the body. “You can walk away from radiation,” Olson said, “but the internal contamination stays with you.”