Japan decides to scrap trouble-plagued Monju prototype reactor — Nikkei Asian Review

” TOKYO (Kyodo) — The Japanese government formally decided Wednesday to decommission the Monju prototype fast-breeder nuclear reactor in western Japan’s Fukui Prefecture, which has barely operated over the past two decades despite its envisioned key role in the country’s nuclear fuel recycling policy.

The decision in a ministerial meeting Wednesday, concluding a process that has included discussion of Japan’s overall fast-reactor development policy by a government panel, comes despite failure to obtain local support for the plan.

The government has invested more than 1 trillion yen ($8.5 billion) in research and development for the reactor, having originally hoped it would serve as a linchpin of nuclear fuel recycling efforts as it was designed to produce more plutonium than it consumes while generating electricity.

With resource-poor Japan relying on uranium imports to power its conventional reactors, the government will continue to develop fast reactors in pursuit of a nuclear fuel cycle in which Japan seeks to reprocess spent fuel and reuse plutonium and uranium, extracted through reprocessing.

But Monju’s fate is sure to prompt further public scrutiny of the fuel cycle policy, with many nuclear reactors left idled after the 2011 Fukushima nuclear power plant disaster. The public also remains wary of nuclear power generation after the disaster.

With the facility’s decommissioning, and the accompanying loss of jobs and subsidies, the central government also risks damaging its rapport with Fukui, which hosts a number of other currently shuttered nuclear plants along the Sea of Japan coast.

The government has calculated it will cost at least 375 billion yen over 30 years to fully decommission Monju. It plans to remove the spent nuclear fuel from the reactor by 2022 and finish dismantling the facility in 2047.

Monju achieved sustained nuclear reactions, technically called criticality, in 1994. But it experienced a series of problems including a leakage of sodium coolant the following year and has been largely mothballed for the subsequent two decades.

Restarting operations at the plant would have cost at least 540 billion yen, according to government forecasts.

“We will decommission Monju given that it would take a considerable amount of time and expense to resume its operations,” Chief Cabinet Secretary Yoshihide Suga told Wednesday’s meeting.

“The nuclear fuel cycle is at the core of our energy policy,” Economy, Trade and Industry Minister Hiroshige Seko told reporters after the meeting. His ministry will take over from the science ministry in overseeing the development of more practical fast reactors.

“We will make full use of the highly valuable knowledge and expertise acquired at Monju as we move forward with fast reactor development…first by concentrating on creating a strategic roadmap,” Seko said.

Earlier Wednesday, the central government held a consultation meeting with Fukui Gov. Issei Nishikawa, who told reporters afterward that he remains opposed to the scrapping of the facility.

Nishikawa said in the meeting that decommissioning cannot begin without the approval of both the prefecture and the city of Tsuruga, where Monju is based.

“The governor told us today…that he wants a more thorough explanation of the specific mechanisms by which decommissioning will be carried out,” Seko said after the decision was made.

“We will create opportunities for dialogue with the local area.”

Nishikawa had said at a similar meeting Monday that the central government had not given enough justification for decommissioning Monju or considered the plant’s operation history sufficiently.

He has also argued that the Japan Atomic Energy Agency, which operates Monju, is incapable of safely dismantling the reactor.

A nuclear regulatory body recommended last year that the JAEA be disqualified from operating the facility following revelations of mismanagement, including a massive number of equipment inspection failures in 2012.

Science minister Hirokazu Matsuno instructed JAEA President Toshio Kodama on Wednesday to come up with a decommissioning plan by around April next year. The government has said it plans to take third-party technical opinions into account in working out how the decommissioning will take place. ”

by Nikkei Asian Review

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Japan finds itself backed into an atomic corner — SimplyInfo

” As Japan begins addressing some of their older nuclear facilities they are discovering the pain other nuclear nations have put themselves in.

The fuel reprocessing plant at Tokai began operating in the 1970’s, some 30 years after the US and UK began their nuclear programs. Officials in Japan are now realizing their facility may be suffering from some of the same short sighted practices.

These are just some of the dangerous conditions found at Tokai:

  • A nuclear waste storage pool with no purification system
  • Corroded barrels of nuclear waste, leaking and entangled in cables
  • Nuclear waste containers with no documentation, no one knows what is in them
  • Liquid waste with a deadly 1500 Sieverts per hour level of radiation
  • Potentially explosive high level nuclear waste

Workers will eventually open these undocumented barrels to see what is in them. This alone could be an extremely dangerous task. Cleaning up the facility is expected to take 70 years. The cost for the first 10 years alone is projected to be $1.92 billion dollars. This facility produced MOX nuclear fuel predominantly from commercial power reactor fuel from Japan’s nuclear power plants. It ceased production in 2006. New safety regulations put in place after the Fukushima disaster caused JAEA to permanently shut the facility. This facility ads to the growing list of nuclear facilities in Japan to face decommissioning.

Japan also has a plutonium problem. The country holds 48 tons of plutonium, enough to make 6000 nuclear bombs. They have been able to reprocess spent nuclear fuel to amass this stash of plutonium under an agreement with the US. This agreement allows them to reprocess nuclear fuel to make MOX fuel. The agreement forbids Japan from using their plutonium for nuclear weapons.

Monju and the foreign MOX program provided plausible excuses to continue possessing the plutonium. Plutonium could potentially be burned in Monju’s reactor. Sending spent nuclear fuel overseas to be turned into MOX provided another excuse that the program was not focused on weapons production. Keeping Monju alive in some manner kept the needed excuse in place. This may be the main reasoning behind starting another fast breeder reactor project in Japan. Even if it were never built, development research could buy Japan 10 years worth of time to avoid dealing with their plutonium issue.

Japan also lacks a viable permanent nuclear disposal facility. Seeing all of these current programs end would force the country to face that problem. As facilities reach end of life, are deemed unsafe or too costly, Japan then has to deal with what to do with them along with proving the country is not becoming a weapons proliferation risk. ”

by Nancy Foust, SimplyInfo

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Scrapping of Monju would mean disposal of 760 tons of radioactive sodium, MOX fuel — The Japan Times

” About 760 tons of radioactive sodium remain in the piping and other equipment of the trouble-prone Monju prototype fast-breeder nuclear reactor, which may be ordered decommissioned, it was learned Sunday.

It has not been decided how to dispose of the radioactive sodium, said sources at the Japan Atomic Energy Agency, the operator of Monju. If the government decides to scrap the reactor, sodium disposal is expected to be a difficult challenge.

Sodium is used as a coolant at Monju, while water is used at conventional nuclear reactors. Sodium is a tricky chemical element that burns intensely if it comes into contact with air or water.

According to the agency, the Monju reactor has some 1,670 tons of sodium. Radioactive substances are contained in 760 tons of the total as it circulates inside the reactor vessel.

The Monju reactor needs to be drained of the sodium if it is to be demolished.

Radioactive and chemically active sodium has to be sealed in containers. There is no precedent of radioactive sodium disposal in Japan.

“We plan to consider the method of disposal if a decision is made to decommission (Monju),” an official said.

Monju, located in Tsuruga, Fukui Prefecture, is a core facility in Japan’s nuclear fuel cycle policy because, if running properly, the reactor produces more plutonium than it consumes.

More than ¥1 trillion, mostly from state budgets, has been invested in Monju. But the 280,000-kw reactor has operated for only 250 days since it reached criticality, or a self-sustained nuclear fission chain reaction, for the first time in April 1994, due to a raft of problems, including maintenance flaws, a sodium leak and fire and attempted coverup.

In November 2015, the Nuclear Regulation Authority advised the government to replace the operator of Monju. The government is carrying out a thorough review of the Monju project, including the possibility of decommissioning the reactor.

The disposal of the mixed-oxide, or MOX, fuel used at Monju is another significant issue. The amount of MOX fuel, a blend of uranium and plutonium recycled from spent nuclear fuel, that needs to be disposed of is estimated at 21 tons, but Japan is not equipped to carry out its disposal.

One option is to consign the disposal to a foreign country and receive the return of uranium and plutonium after the processing, along with radioactive waste.

But the agency’s cost estimate of ¥300 billion for decommissioning Monju does not include the expense of the overseas entrustment of MOX fuel disposal.

The agency aims to entrust France with the disposal of some 64 tons of MOX fuel that has been used at its Fugen advanced converter reactor, but no contract has been concluded. The Fugen reactor, also in Tsuruga, is slated to be decommissioned.

Spent MOX fuel contains larger amounts of highly toxic radioactive substances than spent uranium from conventional reactors.

The disposal of radioactive sodium and MOX fuel at Monju is emerging as an additional and difficult challenge for the government at a time when the final disposal site has not been decided for high-level radioactive waste from nuclear plants across Japan. ”

Jiji

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Reuse of radioactive soil approved despite 170-year safety criteria estimate — The Mainichi

” An Environment Ministry decision to allow reuse of contaminated soil emanating from the Fukushima nuclear disaster under road pavements came despite an estimate that it will take 170 years before the soil’s radiation levels reach safety criteria, it has been learned.

According to the revelation, an Environment Ministry panel approved the recycling of tainted soil generated from Fukushima decontamination work despite an estimate presented during a closed meeting of a working group that it will require 170 years for radioactivity concentrations in the contaminated soil to drop to legal safety standards, shelving a decision over whether such soil should be put under long-term management.

The ministry is planning to allow reuse of the tainted soil in mounds beneath road pavements, asserting that radiation will be shielded by concrete covering such mounds. However, an estimate presented at the closed meeting of the working group on the radiation impact safety assessment states that such mounds would be durable for just 70 years, suggesting that the soil would need to be managed for another 100 years after its road use ends.

“There’s no way they can manage the soil for a total of 170 years without isolating it,” said an angry expert.

The working group is a subgroup of an Environment Ministry panel called “the strategic panel for technical development of volume reduction and reuse of removed soil in temporary storage,” and the two groups share some of their members. According to the working group’s in-house documents obtained by the Mainichi Shimbun, the closed meetings were held six times between January and May, with the attendance of over 20 people including eight group members and officials from the Environment Ministry and the Japan Atomic Energy Agency (JAEA).

Under the Act on the Regulation of Nuclear Source Material, Nuclear Fuel Material and Reactors, the safety standards for recycling metals and other materials generated from the decommissioning of nuclear reactors are set at up to 100 becquerels of radioactive cesium per kilogram. Meanwhile, the special measures law concerning decontamination of radioactive materials, which was enacted after the 2011 Fukushima No. 1 Nuclear Power Plant crisis, classifies materials whose radiation levels top 8,000 becquerels per kilogram as designated waste, and stipulates that waste whose radiation levels are 8,000 becquerels or lower can be put to ordinary disposal.

According to working group chairman and Hokkaido University professor Tsutomu Sato, the group served as a forum to “prepare itself for theoretical argument” over setting the upper radiation dose limit for reusing contaminated soil at 8,000 becquerels.

The Environment Ministry set forth the plan to reuse contaminated soil in public works such as in mounds beneath road pavements and in coastal levees on the grounds that the “radiation levels can be contained to levels on par with clearance levels” by covering tainted soil with concrete and other materials. During the second meeting of the working group on Jan. 27, a member pointed out, “The problem is what to do with tainted soil after use (in roads and other structures). If such soil is allowed to be dug over freely, it would be difficult to convince the upper limit of radiation levels (for soil reuse).”

A JAEA official presented the aforementioned estimate, saying, “For example, it will take 170 years for radiation levels to reduce to 100 becquerels if tainted soil of 5,000 becquerels is put to reuse. Because the durable life of soil mounds is set at 70 years, a total of 170 years will be required to manage that soil — both when the soil is being used in mounds and after that.”

Discussions on the soil management period never went any further, and the strategic panel overseeing the working group on June 7 approved recycling such contaminated soil on condition that the maximum radiation levels of such soil be 8,000 becquerels and that the levels should be no more than 6,000 becquerels if the soil is covered with concrete and no more than 5,000 becquerels if the soil is planted with trees.

The Environment Ministry is set to begin a demonstration experiment possibly later this year, in which radiation levels will be measured in mounds using soil with different radioactivity concentrations at temporary storage sites in Fukushima Prefecture.

Working group chairman Sato, who also serves as a member of the strategic panel, admitted the existence of the 170-year estimate, but said, “We have discussed the matter but haven’t decided anything. We just presented our initial idea for reuse (of tainted soil) this time, and we will examine the feasibility of the plan later.”

Hiroshi Ono, who headed the Environment Ministry’s decontamination and interim storage planning team, said, “We have yet to decide what to do (with the tainted soil) in the end (after reuse), but the Environment Ministry will take responsibility for that.”

Another working group set up under the strategic panel, whose members primarily comprise those from the Japan Society of Civil Engineers, has presented a view, stating, “It will be in no way easy to secure the traceability (of recycled tainted soil).” “

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US, others worried over Japan’s plutonium stockpile — Chicago Tribune

Read the Chicago Tribune’s article on concerns over Japans’s plutonium stockpile in light of the expiration of the 1988 Japan-U.S. atomic energy agreement that will either be automatically extended, revised or unilaterally scrapped in July 2018.

 

Researchers: No doubt cleanup at Fukushima nuclear plant contaminated rice crops in 2013 — The Asahi Shimbun

” MINAMI-SOMA, Fukushima Prefecture–Radioactive substances that contaminated rice paddies here in 2013 came from the crippled Fukushima No. 1 nuclear plant, an international group of researchers said, rejecting a denial issued by Japan’s nuclear safety authority.

The researchers, led by Akio Koizumi, a professor at Kyoto University’s Graduate School of Medicine, reached the conclusion after analyzing radioactive substances and taking spot readings of radioactivity levels around Minami-Soma.

Koizumi presented the final report of the group, consisting of 11 researchers from Japan, Europe and the United States, to local farmers and other parties at a community center in Minami-Soma on Jan. 17.

“The cause of further contamination was the radioactive particles dispersed from contaminated rubble during the cleanup effort at the Fukushima No. 1 nuclear plant,” Koizumi concluded in the report.

Earlier, the agriculture ministry and the Nuclear Regulatory Authority (NRA) gave different views on the source of the contaminated rice.

In 2013, rice crops from areas of Minami-Soma were found with unexpectedly high radioactivity levels more than two years after the triple meltdown at the nuclear plant located 20 kilometers south of the city.

One theory was that highly radioactive substances were dispersed when workers were lifting and removing contaminated rubble at the Fukushima plant on Aug. 19 that year. Two workers at the plant were exposed to high doses of radiation during the cleanup process.

The Ministry of Agriculture, Forestry and Fisheries said the cause of the contaminated rice was “unknown” although it acknowledged “the possibility of the dispersal of contaminated dust.” The farm ministry discontinued its investigation without specifying the source of the contamination.

The NRA, however, said the contaminated rice was not related to the cleanup work at the nuclear plant.

The Minami-Soma city assembly expressed outrage over the NRA’s stance. Some in the city suspected the NRA of a cover-up.

Koizumi and the other researchers digitally recreated an accidental dispersal of contaminated dust from the plant in August 2013.

They used a new analysis system to estimate the amount of radioactive cesium that spread toward Minami-Soma based on radioactivity readings around the city and other factors.

The group’s cesium estimate was more than 3.6 times the amount initially estimated by the NRA.

The research group in September 2014 also collected soil samples from 10 locations around the contaminated rice paddies to determine the amount of strontium 90 in the area.

They confirmed that the ratio of strontium 90 to radioactive cesium in the soil samples was similar to the ratio that would be found near the Fukushima nuclear plant.

Beta-ray emitting strontium 90 is less airborne and tends to remain within close proximity of nuclear weapon testing sites or nuclear accidents. Radioactive cesium is more volatile and can easily adhere to fine dust spread by the wind.

In general, the amount of strontium 90 decreases the farther it gets from a nuclear plant, compared with radioactive cesium. In fact, hardly any strontium 90 has been detected far away from the Fukushima plant.

Based on the amounts of radioactive particles recorded around Minami-Soma, the researchers concluded that a highly irregular plume of radioactive cesium reached Minami-Soma on the third week of August 2013.

“Every single piece of data in the paper supports the fact that contamination by radioactive dust came from the debris at the nuclear plant,” Koizumi said.

Asked about the NRA’s conclusion, Koizumi said: “It seems they were blinded by their estimated amount of dispersed particles, and their choice for the analysis system was misguided. This kind of attitude would only increase the anxiety of residents in the affected areas.”

The group’s findings were published in the international academic journal Environmental Science & Technology last month after a peer review. ”

by Masakazu Honda and Miki Aoki

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