TOKYO (Reuters) - Plutonium found in soil around the crippled Fukushima nuclear complex added to mounting problems on Tuesday in Japan’s battle to contain the world’s worst atomic crisis since Chernobyl.

Plant operator Tokyo Electric Power Co (TEPCO) said the radioactive material, which is used in nuclear bombs, was traced in soil at five locations at the plant, hit by an earthquake and tsunami on March 11.
The under-pressure company stressed the traces were not at dangerous levels.
“Plutonium found this time is at a similar level seen in soil in a regular environment and it’s not at the level that’s harmful to human health,” TEPCO vice-president Sakae Muto told reporters at a briefing.
Muto said the level was similar to that found in the past in other parts of Japan as a result of nuclear testing abroad. He said it was unclear where the plutonium was from, although it appeared two of the five finds were related to damage from the plant rather than from the atmosphere.
The International Atomic Energy Agency (IAEA), the United Nations nuclear watchdog, said the find was to be expected.
“It is reactor-grade plutonium which is formed into the reactor as far as we can see,” IAEA official Denis Flory said. “It means that there is degradation of the fuel, which is not news. We have been saying that consistently for so many days.”
The plutonium discovery, from samples taken a week ago, was reported after TEPCO said on Monday highly radioactive water had been leaking from one reactor.
In a growing list of problems, the environmental group Greenpeace said it had detected high levels of radiation outside an exclusion zone.
Fires, explosions, radiation
Fires, explosions and radiation leaks have forced engineers to suspend efforts to stabilize the plant, including at the weekend when radiation levels spiked to 100,000 times above normal in water inside reactor No. 2.
A partial meltdown of fuel rods inside the reactor vessel was responsible for the high levels, although Chief Cabinet Secretary Yukio Edano said the radiation had mainly been contained in the reactor building.
TEPCO said later radiation above 1,000 millisieverts per hour had been found in water in concrete tunnels that extend beyond the reactor.
The nuclear crisis has compounded Japan’s agony after the magnitude 9.0 quake and huge tsunami devastated its northeast coast, turning towns into apocalyptic landscapes of mud and debris.
More than 11,000 people are confirmed dead and 17,339 are missing. About a quarter of a million people are living in shelters and the cost of damage could top $300 billion, making it the world’s costliest natural disaster.