e.nikkei/e/fr/tnks/Nni20120815D15HH187.htm Nikkei August 15 2012 Decommissioning Of Fukushima To Be Long, Costly Process FUKUSHIMA (Nikkei)–The government and Tokyo Electric Power Co. (9501) have made the first revisions to a plan to decommission the crippled Fukushima Daiichi nuclear power plant, but the details remain uncertain. At the Chernobyl plant, efforts are now in full swing to build a massive shelter to stop the site from releasing radiation into the environment. Among other matters, the revisions involve adding measures to prevent radioactive water from leaking into the environment. But it is still unclear how much time and money this will actually entail. The decommissioning of a nuclear power plant involves removing nuclear fuel and dismantling the reactors before turning the site into a vacant lot. But this process can be dangerous and complicated. It will be especially dangerous to remove the remaining nuclear fuel because of the high levels of radiation that such substances emit. Past Precedent However, the situation at the Chernobyl nuclear power plant, the site of a catastrophic accident 26 years ago, offers a number of ideas about what lies ahead for efforts to dismantle the Fukushima facility. At the Chernobyl plant, about a three-hour drive from the Ukrainian capital of Kiev, efforts are now in full swing to build a massive shelter to stop the site from releasing radiation into the environment. The semi-cylindrical steel shelter, which is being built on a site about 500m from the plant, is 108m high and 150m wide. It is being designed to entirely cover Unit 4, which exploded in April 1986 and released radiation into the atmosphere. Construction of the shelter is scheduled for completion in October 2015. Once the reactor is covered by the shelter, two small cranes will be used to recover nuclear fuel from the reactor, which is now encased in a concrete shelter, or “stone coffin.” In the wake of the accident, the fuel melted and reacted with soil and rock to form highly radioactive black lumps. The radiation level of the solidified nuclear fuel has fallen to 5 millisieverts per hour, from 80 sieverts immediately after the accident occurred. But conditions are still dangerous for the 3,500 workers now cleaning up the site. And some 200 tons of nuclear fuel still remain at the bottom of the reactor. Yet the situation at the Fukushima plant is different in a number of important ways, experts claim. “At Chernobyl, the nuclear fuel melted and flowed out to reach all corners of the lower parts of the reactor,” said an executive officer at the Nuclear Safety Research Association. “The work may be less difficult at the Fukushima plant, where the fuel remains within the containment vessels.” But the conditions within the crippled Fukushima reactors remain unclear. The revisions to the plan to decommission them includes steps to effectively assess the situation inside the reactors in advance. But it will be a long time before such crucial details become clear. Cost Concerns The cost of the entire decommissioning project will likely be high. At Chernobyl, construction costs for the shelter alone will reach approximately 1.54 billion euros (about 149 billion yen). The amount of money that has already been spent on the cleanup has not been revealed. However, it is clear that the project will place a huge, long-term fiscal burden on the government of the Ukraine. Tokyo Electric Power has estimated the cost of decommissioning the Fukushima plant at approximately 900 billion yen. But the utility, known as Tepco, has admitted that this might not be an accurate estimate. The costs will almost certainly continue to rise over time. Some experts have even estimated the eventual total at several trillion yen. Surging costs will probably force Tepco to raise electricity rates and push the government to provide additional financial aid to the embattled utility. This will almost certainly affect taxpayers. A Ukrainian government official in charge of dealing with the situation at the Chernobyl plant recently said that the only viable approach is to move forward slowly and steadily, one step at a time. The current plan involving Tepco and the government, which could extend for 30 to 40 years, is fraught with problems. The only certain thing is that it will be a long, extremely costly process. –Translated from an article by Nikkei staff writer Atsunobu Takeshita (The Nikkei, Aug. 15 morning edition)
Posted on: Fri, 26 Dec 2014 07:14:49 +0000
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