News Watch 155 July./Aug. 2013 Nuke Info Tokyo No. 155
Decommissioning of Fukushima Daiichi’s four reactors rescheduled to be completed earlier than originally planned
Radioactive leak at the Japan Proton Accelerator Research Complex (J-PARC)
Japan Nuclear Fuel Ltd. and Areva issue a statement of cooperation
Vitrification tests end at the Rokkasho Reprocessing Plant
Fukushima Prefecture renews demands for the decommissioning of all nuclear power plants in the prefecture
“Frozen soil method” to prevent the inflow of groundwater
Decommissioning of Fukushima Daiichi’s four reactors rescheduled to be completed earlier than originally planned
On June 27, 2013, the Japanese government’s Council for the Decommissioning of TEPCO’s Fukushima Daiichi Nuclear Power Station (chaired by the Minister of Economy, Trade and Industry, Toshimitsu Motegi) adopted the revised version of the mid-and-long-term roadmap toward the decommissioning of Tokyo Electric Power Company’s Fukushima Daiichi Nuclear Power Station Units 1 to 4. The media reports that, compared with the original roadmap established in December 2011, at the earliest the four reactors are planned to be decommissioned between one and six months ahead of the originally scheduled date.
The revised roadmap does not in fact simply shorten the period required for the decommissioning. In consideration of the condition of each reactor, the revised roadmap sets out multiple plans with differing target dates for the completion of each stage of the decommissioning process, such as the relocation of fuel from the spent fuel storage pools and the removal of molten fuel debris (mixed with molten control rods and other components). The completion of decommissioning may be delayed beyond the originally scheduled date depending on the plans that are actually selected.
The debris removal is planned to be performed with the containment vessels filled with water, partially to reduce worker exposure to radioactivity. (Other alternative debris-removing methods will also be studied because filling the containments with water may be problematic in terms of earthquake resistance.) The decommissioning plan for the reactor equipment itself will be mapped out in detail after the fuel has been relocated from the spent fuel storage pools, the debris removed, and the water remaining under the reactor buildings is disposed of.
On June 28, the Nuclear Regulation Authority was given an explanation about the revised roadmap. One commissioner, Toyoshi Fuketa, criticized the plans by saying, “This looks like apple pie in the sky. Resolving the problems at hand must come first, rather than this final decommissioning process [such as debris removal].”
Radioactive leak at the Japan Proton Accelerator Research Complex (J-PARC)
On May 23, 2013, an accident involving the leakage of radioactive materials occurred at the Japan Proton Accelerator Research Complex (J-PARC), Tōkai Village, Ibaraki Prefecture. In the complex operated by the Japan Atomic Energy Agency (JAEA), researchers and graduate students who were conducting an experiment in the radioactivity-controlled area were exposed to radiation, and the radioactive materials were leaked outside the complex.
J-PARC is jointly run by the JAEA and the High Energy Accelerator Research Organization (KEK), Tsukuba City, Ibaraki Prefecture. On the day when the accident occurred, the researchers and students were conducting an experiment to generate elementary particles by irradiating a gold object with a high-energy proton beam. When the energy of the beam became excessively high, the gold object was fused and evaporated, generating radioactive substances. These substances spread, exposing 34 researchers and students to a radiation dose of 0.1 to 1.7 millisieverts. The researchers handled the accident in an absurd manner: They reset the alarm device and continued the experiment while causing the radioactive material to spread outside the building through a ventilation fan.
The report of the accident to the Nuclear Regulation Authority and Ibaraki Prefectural Office was delayed. It was finally reported 36 hours after the occurrence of the accident. The ventilator fan continued to spin for nearly three days.
Japan Nuclear Fuel Ltd. and Areva issue a statement of cooperation
On June 7, 2013, Japanese Prime Minister Shinzo Abe and French President François Hollande agreed on and released a joint statement to promote comprehensive cooperation in the field of nuclear power. In step with this, Japan Nuclear Fuel Limited (JNFL) and Areva released a Joint Statement on the Future of Nuclear Fuel Recycling. Areva says in the statement that it will support JNFL concerning all the facilities of the Rokkasho Reprocessing Plant, including the high-level liquid radioactive waste vitrification furnaces, in addition to those covered in past technical transfer agreements.
Vitrification tests end at the Rokkasho Reprocessing Plant
The Rokkasho Reprocessing Plant, Aomori Prefecture, performed a high-level liquid radioactive waste vitrification test on furnace A of the vitrification facility from May 8 to May 26, 2013. The test on vitrification furnace B was completed on January 3. “All tests required before pre-operational inspection by the authorities have been completed,” says Japan Nuclear Fuel Ltd. (JNFL), the operator of the plant.
The Nuclear Regulation Authority plans to perform the pre-operational inspection on the plant after the new regulation standards take effect in December 2013. JNFL has not withdrawn its official stance that the plant would be completed in October 2013, but seems to understand the probability of a further delay in plant completion. At a press conference, the JNFL president, Yoshihiko Kawai indicated that completion in October would in fact be difficult.
Fukushima Prefecture renews demands for the decommissioning of all nuclear power plants in the prefecture
Yuhei Sato, governor of Fukushima Prefecture, handed a written request to Prime Minister Shinzo Abe on June 12, 2013 demanding that all nuclear power plants in the prefecture be decommissioned. The governor made the same request to Naomi Hirose, president of Tokyo Electric Power Company (TEPCO), on June 28. At the TEPCO shareholders’ annual meeting held on June 26, the governor favored a shareholder proposal demanding that the Fukushima Daini Nuclear Power Station be decommissioned. It was the first time that the Fukushima governor had approved of a shareholder proposal against nuclear power generation. (The proposal was voted down by a slim majority.) The representatives of Shirakawa City and Minami Soma City, Fukushima Prefecture, were also in favor of the proposal. Furthermore, Shirakawa City favored a proposal demanding that the Kashiwazaki-Kariwa Nuclear Power Station in Niigata Prefecture be decommissioned. (This proposal was also voted down.)
Contradicting the election pledge of the LDP Headquarters, the Fukushima Chapter of the ruling Liberal Democratic Party has adopted the pledge for the July 21 Upper House election that all nuclear power plants in the prefecture be decommissioned.
“Frozen soil method” to prevent the inflow of groundwater
To prevent the inflow of groundwater into the Fukushima Daiichi Nuclear Power Station premises, the plan is to create a shielding wall made from frozen soil around the plant. On May 30, Minister of Economy, Trade and Industry, Toshimitsu Motegi, directed Tokyo Electric Power Company President Naomi Hirose to construct a frozen soil wall. Doubts are being voiced about the effects of a wall created by this method, which actually sounds very beneficial to general contractors.
