MOX a concern in Japan reactor

Mixed-oxide fuel more difficult to control, experts say
A man carries a heat blanket as he leaves a radiation emergency scanning centre in Koriyama, Fukushima Prefecture, Japan, Tuesday, March 15, 2011 four days after a giant quake and tsunami struck the country's northeastern coast.

Scientists warned this week of yet another complication in Japan’s  nuclear crisis: O ne of the doomed reactors is loaded with mixed-oxide fuel that contains plutonium.

 

“This sort of plutonium fuel is more difficult to control than uranium fuel,” said Arjun Makhijani, a nuclear scientist and  the  president of the Institute for Energy and Environmental Research.

The fuel, known generically as  MOX,  was made by nuclear giant AREVA in France, where MOX technology has been used for almost two decades.

The rods, made by blending small amounts of plutonium with traditional uranium, were loaded into  Unit 3 of the Fukushima Dai - ichi nuclear plant last September.

Makhijani said the unit contains 32 MOX assemblies , about 5 percent of the fuel now in the reactor, where an explosion this week kindled fears of a radiation release.

“With this fuel, the risks of accidental criticality are different,”  Makhijani said. “You have the same kinds of problems ; they are just more intense with plutonium.”

AREVA is also part of Shaw AREVA MOX Services – the group building the National Nuclear Security Administration’s $4.86 billion MOX plant at Savannah River Site.

The MOX fuels used in the Japanese reactor and several dozen others are a mixture of uranium and plutonium reprocessed from spent uranium, but the facility at SRS is designed to use weapons - grade plutonium from dismantled nuclear warheads to make fuels
usable in commercial nuclear  reactors.

The plant’s mission is to dispose of the weapons - grade material to prevent exploitation by terrorists. T he search for utilities willing to use the fuel when production starts in 2018 has moved slowly.

Currently, the Tennessee Val­ley Authority is evaluating the use of MOX fuel in as many as five of its reactors, and a Richland, Wash., utility is mulling
its use in one unit, but no formal user agreements have been signed.

Safety officials have pointed out that the problems in Japan were caused by the  combined effects of the earthquake and tsunami –  not by the type of fuel in the  reactors.

In an e-mailed statement Tues­day, a National Nuclear Security Administration spokesman said U.S. officials remain confident about the safety of existing programs.

“The American people should have full confidence that the U.S. has rigorous safety regulations in place to ensure that our nuclear power is generated safely and responsibly,” the spokesman said. “Information is still coming in about the events unfolding in Japan, but the  administration is committed to learning from Japan’s experience as we work to continue to strengthen America’s nuclear industry.”

More

Italy earthquake kills dozens

 

AMATRICE, Italy — A strong earthquake in central Italy reduced three towns to rubble as people slept early Wednesday, with... Read more

Britain votes to leave EU; leader to quit; markets rocked

LONDON — Britain voted to leave the European Union after a bitterly divisive referendum campaign, toppling the prime minister Friday,... Read more