Japanese officials have discovered radioactive contamination on a canister containing highly radioactive nuclear waste sent from Europe.
The discovery raises concerns over the standards maintained during the controversial first shipment of waste from a European reprocessing plant back to Japan, earlier this year.
Although there does not appear to have been any direct human health hazard, any hitch in the delivery is bound to be embarrassing both to the French reprocessor Cogema and its United Kingdom counterpart, British Nuclear Fuels.
Japan is the most important foreign customer for both companies and this was intended as a trial run demonstrating the feasibility of a series of shipments over the next couple of decades.
The consignment of 28 canisters was shipped from Cherbourg by a subsidiary of BNF, Pacific Nuclear Transport Ltd, and arrived at the Rokkasho Nuclear Fuel Cycle Facilities in northern Japan in April.
Japan Nuclear Fuel Limited (JNFL) is carrying out further tests today to try to discover the source of the contamination. It is not clear whether the canister is leaking or if the contamination comes from elsewhere. A formal inspection report from JNFL to the Japanese government's Science and Technology Agency has been postponed indefinitely.
The company appears to believe that when the waste, mixed into molten glass, was being poured into the steel canisters, some spilt and was not washed off properly by Cogema, the French nuclear fuel cycle company, before dispatch from its reprocessing plant. However, other commentators in Japan have suggested that the canister itself may be leaking.
On their arrival, JNFL carried out seven different tests on each canister. One failed the inspection carried out to assess the performance of its seal.
According to a company spokesman, on 10 August radioactive caesium was detected on the exterior of one canister. The company believes that, had the caesium got there via a leak from the inside, they would have expected to find another radioactive element, ruthenium, as well. But a repeated test found only caesium, suggesting that it had come from the outside, perhaps when the canisters were being filled.
The tests were repeated on 15 August and caesium was again found. The series of inspections should have been completed by 16 August but are having to be done again today. As a result, the inspection report has been delayed. A spokesman for JNFL insisted there was no public health hazard.
A spokesman from the Tokyo office of Greenpeace said:"We're not really sure what's going on and this is one of our worries. JNFL insist that it's never happened before, but this is the first time that these containers have ever been used. If there's a problem now, it could happen again. JNFL have no experience of this. Their facilities are only designed to receive safe canisters, and they have no strategy for dealing with problems like this. They say the responsibility lies elsewhere but now these substances are on Japanese soil, what can they do? They can't send the canisters back."Reuse content