As foreign assignments go this must be just about the most dangerous going.

A US recruiter is hiring nuclear power workers in the United States to help Japan gain control of the stricken Fukushima Daiichi plant, which has been spewing radiation.

The qualifications: Skills gained in the nuclear industry, a passport, a family willing to let you go, willingness to work in a radioactive zone.

The rewards: Higher than normal pay and the challenge of solving a major crisis.

"About two weeks ago we told our managers to put together a wish list of anyone interested in going to Japan," said Joe Melanson, a recruiter at specialist nuclear industry staffing firm Bartlett Nuclear in Plymouth, Massachusetts.

So far, the firm has already signed up some workers who will be flying to Japan on Sunday.

Melanson said there will be fewer than 10 workers in the initial group. Others are expected to follow later, he added.

Plant owner Tokyo Electric Power has appealed to the nuclear industry outside of Japan for assistance as the crisis has spiraled beyond their control.

On Thursday, the company said radiation levels in water found in tunnels under the plant was 10,000 times the normal level and radioactive iodine 131 was found in ground water near No.1 reactor of the complex.

Melanson said Bartlett Nuclear had been approached by sub-contractors linked to the General Electric-Hitachi nuclear joint venture. GE designed the Fukushima reactors.

"At first, we had no details about the duration of the job or the positions needed. The only requirement was that you have a valid passport," Melanson said.

But as the job details came in, Bartlett managers scoured the list of volunteers and selected several engineers and technicians "we knew would perform well for us over there".

So just what type of person would go into a damaged nuclear plant that is throwing out dangerous levels of radiation?

Not roughnecks

Melanson said these are not roughnecks prepared to risk their health for a quick paycheck but senior technicians and engineers who have come up through the ranks.

Some have families. "Anytime we have international business, it's up to the workers to square it with their wives."

Japan has put in an exclusion zone of 20 kilometres around the plant. Several experts have recommended that zone should be expanded.

Melanson could not say for certain where the workers would stay but said initially they would be based in Tokyo and drive the 480 kilometre round trip to the Daiichi plant. Translators will be provided so they don't have to speak Japanese.

"The pay will definitely be better than the average pay (for a nuclear technician) over here," Melanson said, but declined to specify exactly what the average salary would be. It is not clear how long they will be working in Japan, but Melanson estimated it would be at least a month.

The workers are not expected to come into contact with the highest levels of radiation.

"These are not 'jumpers' rushing into a room. TEPCO is bringing in robots to help limit human exposure to high levels of radiation," he said.

"Jumpers" is the industry term for people who enter highly radioactive environments to quickly perform a task. The practice was common in the United States in the 1970s and early 80s.

"It's still a job that exists but it's much rarer than in the past - the job is mostly performed mechanically with engineered robotics these days," said Rock Nelson, staffing manager at Nelson Nuclear Corp in Richland, Washington, who has worked in the nuclear industry for almost 30 years.

Melanson said the workers would receive all the equipment needed to do their jobs and safeguard their health.

The roles include ground water and radiation specialists, and spent fuel experts.

Other international nuclear firms have also sent workers to Japan, including France's Areva SA and US-based Westinghouse.

Some experts think the crisis could take months to resolve.

"Tepco will be facing specific and unique problems in each plant," said Nelson.

"Each specific problem may require the engineering of a specific piece of machinery. They will almost certainly have to send a jumper or two in but only as a last resort. This is going to run on for weeks if not months."