The safest way for plutonium disposal

Published in The Hindu on May 10, 2012

There are 500 tonnes of separated plutonium (Pu) worldwide that can be used for making one lakh nuclear weapons, claim four scientists in a paper published today (May 10) in Nature . So if this huge stock is not required for making weapons, which route should nations opt to dispose them?

The options are limited to just two — direct disposal by immobilising the element in ceramic and burying it in repositories or using it in fast breeder reactors.

Incidentally, the second option will end up producing more plutonium! In fact, the Department of Atomic Energy (DAE) depends on fast breeder reactors to produce additional plutonium, which will become the source of fuel for future fast breeder reactors. India is not alone. France is a leader in fast breeder nuclear reactor technology and produces its bulk of energy through the nuclear reactor route.

The United Kingdom last December decided to use separated plutonium in water-cooled nuclear power plants, quite similar to those of the U.S. The four researchers, however, make a strong case why U.K. should desist from taking this route.

It is a “dangerous and costly” proposition that actually “prolongs the associated international security risks,” they state. They make a fervent plea for the government to “seriously evaluate the less costly and less risky” option of direct disposal of the man-made element.

But Britain’s decommissioning authority in 2009 found that such direct disposal, though less expensive than converting into MOX fuel (used in fast breeder reactors), is “technologically less mature.”

Though in 1999 the U.S. initially opted to go in for direct disposal, it reconsidered its decision owing to Russia’s objection — the plutonium so disposed (direct disposal) “could be made into weapons if it were recovered.”

But the authors suggest a ‘solution’ to this vexing problem — mixing plutonium with gamma-emitting waste to “ward off any thieves or terrorists for a century.”