Concerns are being raised in Japan about the raised radiation levels – above legal limits – discovered on the surface of some of the canisters of vitirified High Level Waste (HLW) shipped recently from Sellafield. In August this year, some 40 tonnes of HLW, contained in 76 canisters were shipped from Barrow docks onboard the Pacific Grebe, the newest ship in the nuclear fleet operated by Pacific Nuclear Transport Ltd (PNTL). Routed via the Panama Canal, the Pacific Grebe completed its maiden commercial voyage at the Mutsu-Ogawara port in Japan’s Aomori prefecture on the 15th September.
As reported in Japan’s Mainichi newspaper this week, the Kyushu Electric utility that owns the HLW has confirmed that, from a batch of 28 canisters being safety tested during transfer to the storage facility at Rokkasho-Mura, 3 had been found to have surface levels of beta and gamma radiation that breached acceptance levels of 4 Bequerels (Bq) per square centimetre – in one case almost 50 times over the limit.
Kyushu Electric, whose representatives were present at Sellafield when the HLW was loaded into the transport flasks, also confirmed that surface radiation levels were within the limits before leaving the UK. Japan Nuclear Fuel Ltd (JNFL) which operates the Rokkasho storage facility is carrying out an investigation into the breaches of acceptance levels.
CORE’s spokesman Martin Forwood said today.
‘This will be of significant concern to Japanese workers who have to handle this highly toxic and dangerous material. The unknown source of this surface contamination makes a mockery of the industry’s claims that HLW shipments pose no risk, and will fuel international opposition to this unnecessary trade in nuclear waste’.
Under the contracts covering Sellafield’s reprocessing of Japanese spent fuel, around 1000 canisters of HLW are destined to be returned to Japan over the next ten years. The latest shipment of 76 HLW canisters was only the second to have been made from Sellafield to Japan. The first, undertaken in January 2010, was itself mired in controversy when, on arrival in Japan, it was discovered that the HLW within the transport flask did not fully tally with the official paperwork – a number of canisters being ‘out of position’ within the holding channels of the transport flask. An impending shipment of HLW to Holland had to be delayed while an investigation was carried out and approval obtained from the UK’s Department for Transport.
In common with all nuclear countries, Japan has no final disposal site for HLW, the waste simply being held in an interim storage facility at Rokkasho-Mura. Located on the northern coast of Japan, Rokkasho hosts a reprocessing plant so beset with technical problems that its opening has already been delayed by some 15 years. Originally scheduled to operate in 1997, the latest target date for commercial operations to begin is now put at 2012.