Thursday, April 13, 2006

 

Water with radioactive materials leaked but kept inside the plant

JNFL reported April 12 to the prefectural government that there was a leak, in the early morning of April 11, at a water tank inside the nuclear fuels reprocessing plant. The tank is to rinse hulls (shredded fuel rods) after the enclosed nuclear materials are dissolved by nitric acid. The water leaked has slight amount of radioactive materials that is moved from the dissolution vessel. 40 litres leaked water had been kept in a "cell" (a chamber sealled by one-meter-thick concrete walls) and recovered properly. JNFL said there is no risks of radioactive impact to the environment, nor any occupational dose.
The leak was occurred when a worker was to take a plug off a pipe of the tank, to connect a flexible metal hose to a connection attachment set on the pipe, to transfer the rinsing water to another tank (water buffer tank). The worker mistakenly take off the plug and the attachment altogether, then the rinsing water spilled out through the pipe over the tray, and was collected in a vessel inside the cell. The tray and the vessel were designed for such an incident.
Ministry of Economy's nuclear safety arm, Nuclear and Industrial Safety Agency, or NISA, issued a statement to the Japanese press, saying that the incident was not the one which imposes a risk on the environment or human, and according to the law the operator JNFL was not even required to notice about such an event to the regulator. NISA also added JNFL may need to improve the operating system if appropriate and necessary.
Here in Aomori Prefecture, and in Rokkasho-mura Village, people accepted the news in a very calm manner.

JNFL announced in the press release, the leaked water contained approximately 6.5 g/litre of Uranium, and 0.025 g/litre of Plutonium.
The place of the leakage can be seen on JNFL website.

Monday, April 10, 2006

 

Interview on IAEA inspector at Rokkasho

An interview on Sherly Johnson of IAEA headquarter by the Japanese public TV channel NHK was on the air on April 7. The TV reported that the IAEA inspection team was in Rokkasho plant to check the transparency of the reprocessing process. Ms. Johnson's response broadcasted in the evening of April 7 was the following.
"This is the largest nuclear facility that we have ever implemented safeguards in a non-nuclear weapons country. So that really has quite a challenge with that. For many years we have been focussing on how to implement it here what would be required. We have been working with Japanese government and with JNFL. So I think it shows how important this facility has been to the IAEA. And over that time, we have developed a very good and solid safeguard approach and this is the time when we get started, and it is exiting time for us also."

 

Eight PWR fuels have been reprocessed

JNFL announced April 10 that after the ten days operation of reprocessing test at its Rokkasho reprocessing plant, it shredded eight spent fuels that were burnt in commercial nuclear reactors in Japan. Almost daily, JNFL annunces on the web site the number of nuclear spent fuels which it has shredded in the day. The web page reporting the operation on April 10 is here (only in Japanese).

Tuesday, April 04, 2006

 

Two PWR fuels have been shredded

JNFL started the first step of reprocessing plant test (active testing) on Friday, March 31. The company showed the operation room and a part of its plant to the press. The newspapers and TVs reported the news widely on April 1 in Japan, saying the commencement of the real spent fuels reprocessing is the key process for the recycle of nuclear fuels. Newspapers also tells the negative aspects, including the plant operation brings the emission of gas and liquid radioactive wastes into the atmosphere and to the sea, and Japan has to keep its nuclear energy policy transparent to the international society to minimise the concern on nuclear proliferation. The future owners of extracted Pu and U mixed oxides, who are Japanese power compnanies operating nuclear power plants, show commitments that they will use Pu-U MOX exclusively for peaceful purposes to generate energy in light water reactors in Japan. (Some amount of Pu may be used in Fast Breeder Reactor in Japan.)
As of April 4, 16:20 JST, JNFL finished shredding two PWR spent fuels, according to the JNFL's website.

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