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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].”
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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.
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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.
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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.
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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.
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“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.
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