快猫短视频

A RARE metallic oxide that resists radiation damage could help solve the
problem of how to dispose of nuclear waste, according to a new study by US,
British and Japanese scientists.

The team says that the synthetic rock and glass materials that are used to
store highly radioactive waste at the moment are prone to crack and leak after
only a hundred years because the radiation dislodges their atoms. But the waste,
which includes plutonium, continues to be radioactive for hundreds of thousands
of years.

The team, from Los Alamos National Laboratory in New Mexico, Imperial College
in London and Osaka University in Japan, has found that the atomic structure of
erbium zirconate (Er₂Zr₂O₇) can survive heavy
radiation bombardment from xenon gas, which is equivalent to the effect of
high-level waste. Another oxide, erbium titanate (Er₂Ti₂O₇),
which incorporates a different metal, suffered considerable damage.

The researchers point out that the two ceramic compounds behaved as their
computer simulations predicted. The ordered pattern of atoms in the titanate was
disrupted by the radiation, while the disordered atomic structure of the
zirconate seemed able to absorb it without harm. They think that oxides with the
same crystal structure as erbium zirconate, and similarly sized atoms, might
also withstand radiation.

Robin Grimes, one of the team from Imperial College, argues that some of
these other oxides might eventually be cheaper to manufacture than erbium
zirconate. They could also resist radiation damage for tens of thousands of
years. 鈥淚f this work points the way towards finding the best radiation-tolerant
material and it is used to encapsulate waste, then it is very
important,鈥� he says.