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| May 31, 2011 |
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| Operation Suspended at Hamaoka Nuclear Plant |
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The Hamaoka Nuclear Plant is located in the coast side of Shizuoka Prefecture, southwest of Tokyo, and regarded as the most vulnerable in the world as it stands just above the fault line to cause earthquakes in the near future in that Tokai region. The plant is owned by Chubu Electric Power Co., which recently made a decision to shut down all the reactors at the plant. Operation had been halted before May 14 and will be suspended until when all safety measures are guaranteed against tsunami. Tsunami preventive measures will not entirely ensure safety of the premise. Absolute safety lies only in decommissioning reactors.
DECOMISSION OF NUCLEAR REACTORS ENSURES ABSOLUTE SAFETY
Hamaoka Must Be Closed
A directive to suspend operation and to build tsunami prevention walls was issued by Premier Kan Naoto in the wake of the nuclear crisis caused by the earthquakes of Magnitude 9 on the Richter scale and the subsequent tsunamis which had struck the Tohoku Region on March 11. The government decision was accepted by the utility, Chubu Electric Power Co.
Some criticize that the government order is not legally endorsed and it was made too abruptly. The policy, however, can be appreciated to an extent that operation is saved before an earthquake though some conditions are attached. Several concerns, however, remain unsolved: what should be done from now on?
Four factors are questionable:
(1) Will operation be resumed at the Hamaoka Plant after the preventive structures against tsunami are completed?
(2) What will happen to other nuclear power plant than the Hamaoka?
(3) What will be done on the projects to construct new reactors?
(4) What should be done for nuclear fuel cycle?
Let's analyze the points. Even though a perfect facility is completed to protect the plant from tsunami, what will happen if a quake directly comes with a scale over the assumed M8? A similar calamity to that of Fukushima Dai-ichi Plant, or far more fatal one might be brought about.
In the Fukushima's case control rods were inserted at the least and nuclear fissions have been deterred. As far as the Hamaoka is concerned, insertion of control rods, which is the key in the critical moment, might be impossible. The reactor type at the Hamaoka is of the boiling water reactor (BWR), the same as that of Fukusima: in an emergency shutdown control rods are inserted from underneath with the driving mechanism.
Huge earthquakes simultaneously tremble vertically and horizontally. Under this condition control rods could not be inserted normally. In addition, judging from the design, BWR control rods easily drop down with extraordinary quakes.
In 2009 a M6.5-level earthquake occurred around the Suruga Bay, near the Hamaoka, which made the driving units out of order on the 30 units out of the total 250 control rods at the No.5 Reactor which was under operation at the quake.
If a reactor should be damaged and nuclear reactions should not be halted, what would happen? : a reckless drive or an explosion? It is horrible. It is out of our imagination.
The Hamaoka must be closed. A sole option is to decommission the reactors in the premise.
Human Lives First
Now let's look at other nuclear plants across the country. Are they safe? - no, far from that. Electric power companies and the sponsoring state governments, promoters of nuclear power generation, have abnormally underestimated dangers of active fault lines: every nuclear plant in fact is proven to stand on these lines. Experts today rectify an extent of danger, presuming it severer.
These fault lines move, affected by motions of the tectonic plates on which Japan's archipelago lies. After March 11 quakes happen very often in the remote regions from the devastated areas. That means active fault lines link with the geologic plates.
Active fault lines and age-old nuclear reactors, absence of Tsunami prevention measure - these factors eloquently tell us only option is to decommission reactors after shutting down the rest of plants, if we respect and defend human lives.
As for new, planned reactors, they should be cancelled once and at all. A gigantic volume of radioactive materials has been produced even without accidents. It is a crime against the humanity. No more crime.
If nuclear power plants are shut down, there will be no need to have a nuclear fuel cycle system. Technologies for the system cannot be attained: the actual situations at the reprocessing facilities of spent fuel and the fast breeder reactor Monju indicate they are impossible and perilous.
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