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Fukushima Daiichi Nuclear Power Station： Decommissioning Roadmap
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Published on September 28 '2011 : The Denki shinbun(The Electric Daily News)
Dr. Michio Ishikawa
Chief Adviser(Former President & CEO)
Japan Nuclear Technology Institute(JANTI)
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When the Obon summer holiday season ended, the focus of the Fukushima issue had shifted to compensation.Not long after that, some media started talking about the decommissioning of the power station.These are clear signs that the situation is becoming under control.
Tokyo Electric Power Company has announced that it plans to fill reactors' containment vessels with water to extract melted fuel rods.Their plan appears to be to break the melted core and store them in containers, according to the procedures taken after the nuclear accident at the Three Mile Island Nuclear Generating Station.
At Three Mile Island, core extraction work began approximately 6 years after the accident.Workers identified the damaged core's exact position and conditions before commencing work.
The extracted fuel debris are now stored at the Idaho National Laboratory, and I heard that the decontamination work for inside the containment vessel has completed.
Japan is just as experienced when it comes to reactor decommissioning.I am referring to the dismantlement and removal of the Japan Atomic Energy Research Institute's power demonstration reactor (JPDR).The work went ahead alongside the world's first decommissioning project at the Shippingport Atomic Power Station in the United States.With neither of the parties having any prior experience, they collaborated together, rather than competing with one another, in proceeding with the task. Here is the inside story.
At the time, there was intense confrontation concerning the projected cost of decommissioning, with figures cited by optimists and pessimists differing by several hundred times, which was one of the reasons for opposing nuclear energy.It was around this time when JPDR presented its estimation of decommissioning cost and associated exposure dose, which turned out to be very close to the estimation by the Shippingport plant.This is why the United States welcomed the JPDR case as a partner project.Both sites completed work by the early 1990s, thereby building the world's technological foundation for nuclear plant decommissioning.
The Association for Nuclear Decommissioning Study is the private-sector research group that has taken over technological exploration in this field.
Decommissioning the Fukushima plants, which contain melted cores, is a difficult challenge due to the strong level of radiation and contamination.However, there is no change to the essence of decommissioning work, which is to remove radioactive materials and restore the site.We have the precedent at TMI and experience from JPDR.The priority is to examine the task at hand, and draw up an essential plan.There is no need to hurry.
Yet, I have a word of warning.On-site adjustment is a fact of life in any work.Considering the complexity of the task at Fukushima, the decommissioning plan will have to undergo a large number of adjustments and changes.They must not be made subject to time-consuming red tape in the name of work permits.On-site work of this nature evolves organically.Failing to seize the right moment would end up increasing work.
This warning is a lesson learned from the Fukushima accident.The question must be asked whether complex plant safety administration over the last decade was of any use in preventing the accident at Fukushima.Indeed, the requirement of detailed paperwork served as the underlying cause of on-site inefficiency and delays.The complicated and troublesome desktop protocols has made workers take light of operating experiences and deprived them of awareness on safety.Decommissioning work must not fall into this pitfall.
The actual work for decommissioning Fukushima will not start for at least several years.Its completion must be a few dozen years away.During this period, the power station must be managed with a high level of awareness.This cannot be achieved unless the task is motivating and inspiring.
An environment with strong radiation is a nuisance for the general public, but could be a valuable field for researchers.How about setting up a special radiation zone on land and at sea, and providing it for radiation studies?
Just like the International Space Station does, this zone should seek international submissions of themes to facilitate diverse research not limited to nuclear energy, under international cooperation.It can then be in charge of the safety management of the power station.
Establishing such a research site has at least three benefits, i.e. enabling on-site examination of the effects of radiation on all matter on this planet, promoting an international study into the accident, and having researchers spread the word about the power station's actual situation from their respective countries in their own languages.This could soften criticism against Japan about its perceived reluctance to release information.
Another incidental benefit would be to boost Japan's international position in handling activities related to nuclear energy.
Furthermore, it would be wonderful if gathering numerous researchers from other countries at the site helped revitalize the devastated local communities.
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