29 Avril 2017
April 23, 2017
Reprocessing is the dirtiest and most dangerous part of the nuclear fuel chain.
Irradiated nuclear fuel contains literally hundreds of human-made radioactive byproducts which are collectively millions of time more radioactive than unused nuclear fuel. Inside the core of a nuclear reactor, the radioactivity of the irradiated fuel is so intense that it can melt the core of the reactor at a temperature of 2800 degrees C (5000 degrees F) even if the reactor is totally shut down.
In a reprocessing plant the intensely radioactive solid fuel elements are chopped up and dumped into a metallic basket suspended in boiling nitric acid, so that plutonium can be chemically extracted from the radioactive liquid solution. Radioactive gases and vapours are released, plutonium-bearing liquid effluents occur, radioactive equipment and piping and left behind, and millions of gallons of high-level radioactive liquid waste are produced.[...]
Japan Atomic Energy Agency:
Closure of Tokai Reprocessing Plant to cost an
estimated 800 billion yen ($10 billion Canadian)
The Japan Times, April 23, 2017
The Japan Atomic Energy Agency has revealed that the scrapping of the Tokai Reprocessing Plant, the nation’s first facility for reusing spent nuclear fuel, will cost an estimated ¥800 billion, an official said.
The state-backed JAEA did not reveal the cost to taxpayers in 2014, when it made the decision to shut down the plant in the village of Tokai, Ibaraki Prefecture, over a 70-year period.
The facility started operation in 1977 as part of Japan’s desire to establish a nuclear fuel cycle, in which all spent fuel is reprocessed to extract its plutonium and uranium to make more fuel. The policy is designed to ensure resource-dependent Japan uses its nuclear fuel as efficiently as possible.
The JAEA decided to scrap the sprawling plant after it became too costly to run under the more stringent safety rules introduced following the 2011 Fukushima nuclear crisis. The facility comprises around 30 buildings and has large areas rife with contamination caused by its task of disassembling spent nuclear fuel.
According to the official, the startling decommissioning estimate is based on an estimate the agency made in 2003. The JAEA is finalizing the assessment and on course to submit it for approval by the Nuclear Regulation Authority as early as June.
The three-tier disposal scheme for the waste generated by the Tokai Reprocessing Plant is based on radiation level.
Waste with the highest radiation level, which will fill some 30,000 drums, will be buried more than 300 meters underground.
Mid-level waste, which will fill about 24,000 containers, is expected to be buried several dozens of meters underground.
Low-level waste, involving another 81,000 drums, will be buried close to the surface, the JAEA said.
In the meantime, the plant’s tainted equipment and facilities will need to be decontaminated and scrapped before being filled with cement and mortar and put in drums for transport to a final disposal site.
The big problem is, there has been little progress in deciding where to bury the drums because they can’t find anyone willing to accept them.
Despite the Fukushima nuclear disaster, the government is trying to resume nuclear power generation and continue its pursuit of a nuclear fuel cycle.
This policy, however, has experienced setbacks from the recent decision to decommission the Monju fast-breeder reactor, an experimental facility in Fukui Prefecture that was considered key to the nuclear fuel cycle plan.
And the completion of a new fuel reprocessing plant in the village of Rokkasho, Aomori Prefecture, has also been largely behind schedule for years.
In the meantime, public concerns about the safety of atomic power remain strong at a time when the government is aiming to make it account for 20 to 22 percent of Japan’s electricity supply by 2030. [Note: In 2011, before the Fukushima-Daiichi disaster, nuclear provided 30% of Japan’s electricity. GE]
The new estimate for decommissioning the Tokai Reprocessing Plant includes ¥330 billion for storing waste underground, ¥166 billion for decontaminating and dismantling the facility, and ¥87 billion for transportation costs.
The JAEA facility is not to be confused with the private uranium-processing facility in Tokai where a fatal criticality accident occurred in 1999.
[See http://tinyurl.com/me8qdvd for a description of the accident and its aftermath. GE]