仏で保管のプルトニウム 九州電力と四国電力の原発で利用へ via NHK News Web

Posted on 2024/02/17 by nfield

2024年2月17日 8時01分

電力各社が保有するプルトニウムの利用が滞る中、大手電力でつくる電気事業連合会は、原発の再稼働が進んでいない電力会社が保有し、フランスで保管されているプルトニウムの一部を核燃料に加工し、九州電力と四国電力の原発で利用する計画を公表しました。

使用済み核燃料に含まれるプルトニウムは、核兵器の原料にもなることから、電力各社はイギリスやフランスに送って再び核燃料に加工したうえで、国内の原発で利用する「プルサーマル発電」を進め、保有量の削減を図ってきました。

しかし、イギリスでは核燃料に加工する工場が2011年に閉鎖され、およそ21.7トンのプルトニウムが利用できなくなっています。

一方、フランスにはおよそ14.1トンが保管されていますが、「プルサーマル発電」を実施する九州電力や四国電力は在庫がなくなっていて、ほかの電力会社では再稼働が進まないこともあり、全体として利用が滞っています。

このため、電気事業連合会は、九州電力と四国電力がイギリスで保管しているプルトニウム1.7トンを、再稼働が進んでいない東京電力や中部電力など5社がフランスで保管している分と交換し、核燃料に加工した上で、2027年度から利用を始める計画を明らかにしました。

[…]

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夜廻り猫[第九二五話]　SPEEDI

Posted on 2024/02/10 by yukimiyamotodepaul

SPEEDI 2024年2月9日

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Congress torpedoes a Biden nominee and casts doubt on nuclear safety via Bulletin of Atomic Scientists

Posted on 2024/02/08 by nfield

By Allison Macfarlane | February 6, 2024

The Biden administration’s recent abandonment of Jeff Baran for another term as member on the US Nuclear Regulatory Commission (NRC) bodes ill for the independence of the agency—and the safety and security of the country. A longtime commissioner, Baran reportedly did not have enough support from some senate Democrats to win another nomination.

His crimes? Being “an overzealous regulator overtly hostile to nuclear energy.”

Senate Democrats say they would prefer a nominee who is not “too focused on safety.” But the NRC is not a pro- or an anti-nuclear group; it’s an independent regulator, whose mission is to protect public health and safety, ensure security, and protect the environment.

Baran’s opponents in the Senate and in public interest groups cited his track record of being the lone NRC commissioner (of five) to consistently vote in favor of more environmental protection and safety. But with the other four votes typically going in the opposite direction, the decisions favored by the nuclear industry often won out. Baran was hardly a threat to the industry. Does the nuclear industry and its supporters really want the NRC to become an echo chamber instead of a balanced and trusted regulator?

[…]

Many in the nuclear industry are hoping to herald a yearned-for renaissance through the commercialization of small modular and advanced reactors. In the United States, none of these reactor designs has ever been constructed, let alone actually demonstrated. That has not stopped the industry and its promoters from claiming that small modular reactors (SMRs) are safer and cheaper than existing large light water reactors—though because they have not been demonstrated, let alone achieved commercial success, the actual costs and safety issues are unknown. For nuclear power supporters, what is holding the industry back from making a dent in fossil fuel usage is the NRC.

Nothing could be further from the truth.

For years, the NRC has worked proactively with the nascent SMR industry, providing guidance as to how to follow the design certification and licensing processes. And recall that Congress structured the NRC as a fee-for-service agency that must recover 90 percent of its budget from fees paid by licensees by law. This means the agency doesn’t get paid until an application is submitted, but regulators have already done a lot of work even before anyone has submitted a license application. And even then, the fees from the agency are a tiny fraction of what it costs to bring a reactor to commercialization. For instance, in the NRC’s Design Certification process, the agency’s fees amount to between 2.5 and 7.5 percent of the total costs of the reactor.

But blaming the NRC for the industry’s woes is a red herring that deflects the real challenges and uncertainties of developing a new technology onto the regulator. Even if the NRC stopped charging fees and gave all license applications a pass on rigorous safety requirements, the SMR industry would still struggle to commercialize its products. That is because the real issue with these reactors is their economics: SMRs are expensive technologies, especially compared to the cheap cost of wind, solar, and natural gas. And costs for renewables keep decreasing every year.

[…]

 To be functional, the NRC must have commissioners who have some technical understanding of nuclear facilities they are supposed to regulate. In the past, commissioners have been drawn from the Navy, academia, and other government agencies.

Over the last 20 years, however, the trend has been to tap congressional staffers—who are by definition political and clearly embody a means for members of Congress to interfere with NRC decision-making—to be commissioners. Such a practice has introduced politics directly into agency processes. The agency performs best, however, when it makes reasonably objective decisions based on expert knowledge of a complex technology. The United States should consider itself lucky compared to other nuclear operating nations because it has a diverse pool of nuclear experts to draw from to sit on the regulatory commission. Sadly, the increasing politicization of the NRC’s Senate confirmation process prevents the agency from benefitting from those experts, which undermines the safety of US nuclear facilities.

[…]

It’s in the industry’s best interests to have an independent regulator. As many in the industry say, “an accident anywhere is an accident everywhere.”

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Advocates demand halt to uranium mine near the Grand Canyon via Salon

Posted on 2024/01/31 by nfield

By Matthew Rozsa

he Grand Canyon truly lives up to its name, being the largest canyon on Earth and one of the most popular national parks in America. But due to uranium mining in the area, some advocates are warning it could become the site of a future environmental disaster, which threatens to make one Indigenous village “extinct.”

More than 80 groups signed onto a statement on Monday — representing Indigenous communities, scientists and environmental nonprofits such as the Sierra Club and the Center for Biological Diversity — directed at President Joe Biden and Arizona Gov. Katie Hobbs, demanding they close the Pinyon Plain uranium mine, which is located near the Grand Canyon.

“We have a choice in front of us. Allowing the Pinyon Plain mine to proceed is subjecting this landscape and its interconnected waters to a legacy of devastation and disregarding the rights of the Indigenous peoples on the land,” Sanober Mirza, Arizona program manager for the National Parks Conservation Association, said in the statement. “Or we can choose a different path — one that holds a promise of protecting the Grand Canyon’s cultural sanctity, its people and natural resources.”

To understand why the mine’s opponents feel so strongly, one can turn to Amber Reimondo, who work as energy director at a conservationist non-profit called the Grand Canyon Trust. Reimondo explained to Salon by email that, on the one hand, Biden permanently banned mining operations on nearly 1 million acres of federal managed lands by creating the Baaj Nwaavjo I’tah Kukveni – Ancestral Footprints of the Grand Canyon National Monument in August 2023. Yet the Pinyon Plain mine was exempt from this prohibition, and Reimondo argues that the impact on the region has been “several fold.”

“The Grand Canyon region as a whole and especially the location of the mine, is deeply significant to Indigenous cultures and is a place where tribal members have conducted ceremonies, collected medicine, hunted, and more, for centuries,” Reimondo said. “The mine also overlies critical and complex [and] not well understood groundwater systems. One aquifer in particular — the Red Wall Muav Aquifer — is the sole source of water for the remote Havasupai Village of Supai inside the Grand Canyon. The mine poses a contamination threat to these groundwater resources not just today, but importantly, after the mine’s mere 28-month operational lifespan has concluded and the mining operator ‘cleans up’ and moves on.”

Supai is so remote, it’s only accessible only by helicopter or an 8-mile mule ride or hike, Reimondo explained, noting that if the newly-oxygenated groundwater comes into contact with nearby rocks, minerals like arsenic and uranium will be dissolved by the groundwater and enter aquifers used by the local community and essential to local ecology, including Havasu Falls. Taylor McKinnon, Southwest Director for the Center for Biological Diversity, expressed similar concerns.

“Ultimately, this mine is going to require political leadership,” McKinnon told Salon in an interview, referring to both the Biden and Hobbs administrations. “Those administration’s agencies have the authority to fix this problem if they so choose, and that’s what they should do.”

[…]

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A million tons of radioactive waste next to the Ottawa River? You Must Be Kidding via Sierra Club Canada

Posted on 2024/01/19 by nfield

By Ole Hendrickson, Chair of Board of the Sierra Club Canada Foundation

The Sierra Club Canada Foundation is condemning a Government of Canada decision to allow 80 years’ worth of its accumulated radioactive waste to be put in a gigantic landfill surrounded by wetlands that drain into the Ottawa River, 1 kilometer away.

Partially treated leachate from the landfill would be discharged either into the wetlands or directly into Perch Lake, a 45 hectare water body that feeds into the Ottawa River on the edge of the Canadian Shield.

After a nearly 8-year-long assessment under the 2012 version of the Canadian Environmental Act, Rumina Velshi, ex-president of the Canadian Nuclear Safety Commission (CNSC), signed off on the so-called “Near Surface Disposal Facility” (NSDF) project on January 9, 2024. Ms. Velshi recently attracted media attention for having spent nearly $100k more on travel than the next closest senior bureaucrat over a 19-month period.

Her signature means that a private consortium contracted by the Harper government in 2015, now made up of two US-based multinationals and AtkinsRealis (formerly SNC-Lavalin), can proceed with construction of Canada’s first-ever permanent disposal facility for nuclear reactor waste, for the convenience of the industry and the benefit of its shareholders.

Under a 10-year federal contract worth more than $10 billion, the consortium was given ownership of a former Atomic Energy of Canada Limited (AECL) subsidiary called Canadian Nuclear Laboratories (CNL). Under a “Site Operating Company” agreement, CNL must reduce the $8 billion federal nuclear liability as quickly and cheaply as possible. The agreement called for an operating waste facility by 2021, which CNL failed to meet owing to significant opposition from First Nations, citizens’ groups, NGOs, and downstream municipalities. CNL’s owners want shovels in the ground before their contract expires in September 2025.

Wastes proposed for the giant landfill are currently stored in 20-foot intermodal containers, 50-gallon drums, and steel waste boxes. They include radioactively contaminated piping, concrete, asbestos, bricks, and lumber from demolition of old structures; and soils contaminated by past dumping of radionuclides mixed with toxic organic chemicals (including PCBs and dioxins) and heavy metals (cadmium, lead, mercury, etc.) in unlined sand trenches. Industrial wastes shipped to Chalk River from companies across Canada would also go in the landfill.

Large amounts of waste were generated by reactor accidents at Chalk River in 1952 and 1958. Facilities used to extract plutonium for nuclear weapons also suffered accidents. These wastes will remain hazardous for thousands to millions of years.

The NSDF’s proximity to the Ottawa River would ensure that detectable quantities of long-lived, man-made radioactive substances and other toxic wastes will pollute the river in perpetuity. The location was chosen to minimize costs of hauling waste from the dozens of radioactively contaminated structures in the “Active Area” at Chalk River.

Ten Algonquin First Nations, on whose unceded land the facility would be built, have registered their objections in the strongest possible terms. They note that section 29(2) of the UN Declaration of the Rights of Indigenous Peoples requires the Government of Canada to obtain their free, prior, and informed consent before disposing of hazardous waste in their territory.

To build the NSDF, CNL would destroy 35 hectares of near old-growth forest adjacent to the Perch Lake wetlands. The forest, unlogged for 80 years, is home to bear dens, a wolf pack, beaver, moose, and turtles. CNL would then blast out the side of a small mountain and install a “plastic geomembrane” it says could contain waste for centuries.

Few Canadians have heard of the NSDF, owing to the heavy veil of secrecy that the Government of Canada maintains over its nuclear installations. It allows unelected CNSC commissioners to make controversial decisions involving nuclear energy, which Parliament declared to be an undertaking “for the general advantage of Canada” under the 1997 Nuclear Safety and Control Act, which has never since been reviewed.

[…]

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劣化ウランを蓄電池「レドックスフロー電池」に再生、世界初の成果目指す via ニュースイッチ

Posted on 2024/01/15 by yukimiyamotodepaul

原子力機構が開発に乗り出す

日本原子力研究開発機構は核分裂せず、原子力発電に使われない劣化ウランを利用した蓄電池の開発に乗り出す。ウランを使った蓄電池は充電ロスが低く、原料が準国産であるため、低価格での販売が見込める。詳細な原理実証ができれば世界初の成果となる。２０３５年には再生可能エネルギーや原発と連携し、余剰電力を蓄電できる仕組みを構築する考え。廃棄物の劣化ウランを有効活用し、資源として平和的に利用することを目指す。

ウランの酸化還元反応に着目し、それを利用して充電・放電する蓄電池「レドックスフロー（ＲＦ）電池」を開発する。これまでに原子力機構は、ウランを利用したＲＦ電池に使う電解溶液の選定などを進めてきた。２４年からウランＲＦ電池の詳細設計を始め、２６―２８年に原子力科学研究所（茨城県東海村）内で実証やスケールアップを実施する予定。

（略）

原子力発電に使われるウラン２３５は天然のウランに０・７％しか含まれない。残りの９９・３％は核分裂しない劣化ウランであり、廃棄物として約１万６０００トンが貯蔵されている。核燃料物質として扱いが難しいウランだが、核分裂しないウランを資源化できればエネルギーの安定化にもつながる。

全文は劣化ウランを蓄電池「レドックスフロー電池」に再生、世界初の成果目指す via ニュースイッチ

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Rokkasho redux: Japan’s never-ending reprocessing saga via Bulletin of Atomic Scientists

Posted on 2024/01/04 by nfield

By Tatsujiro Suzuki | December 26, 2023

According to a recent Reuters report, Japan Nuclear Fuel Ltd (JNFL) still hopes to finish construction of Japan’s long-delayed Rokkasho reprocessing plant in the first half of the 2024 fiscal year (i.e. during April-September 2024). The plant—which would reprocess spent nuclear fuel from existing power plants, separating plutonium for use as reactor fuel—is already more than 25 years behind schedule, and there are reasons to believe that this new announcement is just another wishful plan that will end with another postponement.

[…]

1993: Construction starts.

1997: Initial target for completion.

2006-2008: Hot tests conducted, revealing technical problems with the vitrification process for dealing with waste produced during reprocessing.

2011: Fukushima Dai-ichi nuclear plant accident.

2012: New safety regulation standards introduced.

2022: Completion target date postponed to June 2024)

The 2022 postponement was the 26th of the Rokkasho project.

[…]

Fourth, the financial costs to JNFL of postponement are covered by the utilities’ customers, because the utilities must pay a “reprocessing fee” every year, based on the spent fuel generated during that year, whether or not the reprocessing plant operates. The system by which the Nuclear Reprocessing Organization of Japan decides the reprocessing fee is not transparent.

Fifth, the project lacks independent oversight. Even though JNFL’s estimate of the cost of building and operating the Rokkasho plant has increased several-fold, no independent analysis has been done by a third party. One reason is that some of the shareholders are themselves contractors working on the plant and have no incentive to scrutinize the reasons for the cost increases or the indefinite extension of the construction project.

After so many postponements, there is reason to wonder whether the plant will ever operate, but the government and utilities continue to insist that the plant will open soon. Even if Rokkasho were to operate, it may suffer from the same kinds of problems that marked Britain’s light-water reactor spent fuel reprocessing experience, as described in Endless Trouble: Britain’s Thermal Oxide Reprocessing Plant (THORP).

Why does Japan’s commitment to reprocessing continue? Despite the serious and longstanding problems the Rokkasho plant has faced (and continues to face), Japanese regulators and nuclear operators have doggedly pursued the project. There are four reasons:

Spent fuel management. Currently, most of Japan’s spent nuclear fuel is stored in nuclear power plant cooling pools. But the pool capacities are limited, and the 3,000-ton-capacity Rokkasho spent fuel pool is also almost full. The nuclear utilities must therefore start operating the Rokkasho plant unless they can create additional spent fuel storage capacity, either on- or off-site. The Mutsu spent fuel storage facility is a candidate for additional capacity, but due to the concern that spent fuel could stay there forever, Mutsu city refuses to accept spent fuel unless the Rokkasho reprocessing plant begins to operate. The Rokkasho plant design capacity is 800 tons of spent fuel per year.

Legal and institutional commitments. Under Japan’s nuclear regulations, utilities must specify a “final disposal method” for spent fuel. The law on regulation of nuclear materials and nuclear reactors states that “when applying for reactor licensing, operators must specify the final disposal method of spent fuel” (Article 23.2.8). In addition, there was a clause that “disposal method” should be consistent with implementation of the government policy, which specified reprocessing as the disposal method. Although that clause was deleted in the 2012 revision of the law after the Fukushima accident, the Law on Final Disposal of High-Level Radioactive Waste still bans direct disposal of spent fuel. In addition, the 2016 Law on Reprocessing Fees legally requires utilities to submit reprocessing fees for all spent fuel generated every year since they stated in their applications that “final disposal method” for their spent fuel would be reprocessing.

Commitments to hosting communities. The nuclear utilities committed—albeit tacitly—to the communities hosting nuclear power plants that they would remove the spent fuel to reprocessing plants, since that was the national policy. Separately, JNFL signed an agreement with Rokkasho village and Aomori prefecture that says that if the Rokkasho reprocessing plant faces “severe difficulties,” other measures will be considered—including the return of spent fuel stored at Rokkasho to the nuclear power plants.

Local governments hosting nuclear power plants were not involved in this deal, however. They could therefore just refuse to receive spent fuel from Aomori. In fact, after the Fukushima accident, when the government was considering amending the nuclear fuel cycle policy to include a “direct disposal option” for spent fuel in a deep underground repository, the Rokkasho village parliament (at the behind the scenes suggestion by the then JNFL president, Yoshihiko Kawai), issued a strong statement asking for “maintenance of the current nuclear fuel cycle policy.”

The statement continued that, if Japan’s fuel cycle policy changed, Rokkasho would: refuse to accept further waste from the reprocessing of Japan’s spent fuel in the UK and France; require the removal of reprocessing waste and spent fuel stored in Rokkasho; no longer accept spent fuel; and seek compensation for the damages caused by the change of the policy.

Institutional and bureaucratic inertia. In Japan, bureaucrats rotate to new positions every two or three years and are reluctant to take the risk of changing existing policies. They therefore tend to stick with past commitments. Institutional inertia becomes stronger as a project becomes bigger. The Rokkasho reprocessing project is one of the largest projects ever in Japan. Changing the project is therefore very difficult.

[…]

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Why Japan should stop its Fukushima nuclear wastewater ocean release via Bulletin of Atomic Scientists

Posted on 2023/11/25 by nfield

By Tatsujiro Suzuki | September 22, 2023

[…]

Part of the radioactive substances that contaminate the water is now being removed by multi-nuclide removal equipment called “advanced liquid processing systems” (ALPS)—an unfortunate name given that the Alps mountain range in Europe is home to some of the cleanest freshwater in the world. After the removal of most radioactive substances—except for tritium, which cannot be removed by the ALPS system—treated water is then stored in tanks (see Figure 2). The ALPS process is supposed to reduce the concentration of radionuclides, except tritium, to levels below regulatory standards. However, according to TEPCO’s data, as of March 31, 2023, of the total of about 1.3 million m3 of treated water, only about a third satisfied regulatory standards and the other two-thirds needed to be re-purified.

[…]

It can’t be denied that “treated water” is not as pure as “tritiated water” because treated water may still contain other radioactive nuclides, albeit in small proportions. But the comparison of Fukushima’s “treated water” with other “tritiated water” released during the normal operation of other nuclear power plants can be misleading because the latter is not contaminated with other radioactive nuclides.

TEPCO says it re-purifies the “treated water” to make sure the water satisfies regulatory standards before it is released to the sea. To do that, the company’s plan is to dilute “treated water” with large amounts of sea water to reach a concentration of tritium of 190 Becquerel (Bq) per liter, which is much lower than the allowed concentration of 1,500 Bq per liter.

The first discharge happened over a period of 17 days and involved a total of 7,800 tons of treated water being released to the sea. TEPCO plans to discharge treated water three more times in 2023, and the total tritium discharge by the end of March 2024 is expected to reach about 5 trillion Bq. This is much lower than the annual discharge target of 22 trillion Bq set before the Fukushima accident.

In addition to tritium, TEPCO must report that the concentration of all other radionuclides is below regulatory standards. To do this, TEPCO uses a simplified index, which corresponds to the sum of ratios of the concentration of each radioactive nuclides (excluding tritium) compared to regulatory standards. If this ratio is below one, it means the concentration of other radionuclides is below regulatory standards. TEPCO reported that the water being discharged during the first period was measured to have an index of 0.28, therefore satisfying regulatory standards. TEPCO said the operation may last at least 30 years to discharge all “treated water.”

Scientific debate. The Japanese government and TEPCO argue that the whole operation satisfies both Japanese regulatory standards and international safety standards. Besides, the Japanese government officially asked the International Atomic Energy Agency (IAEA) to conduct an independent review of the safety of the ALPS treated water release. On July 4, 2023, the IAEA published its “comprehensive report,” which concluded that the ALPS process is “consistent with relevant international safety standards” and that “the discharge of the treated water [into the sea], as currently planned by Tepco, will have a negligible radiological impact on people and the environment.”

But there are scientific arguments against TEPCO’s release plan.

The Pacific Island Forum expressed its concern in a statement in January 2023 about whether current international standards are adequate to handle the unprecedented case of the Fukushima Daiichi tritiated water release. Based on a report from an independent expert panel established by the forum, TEPCO’s guideline compliance plan does not appear to include the transboundary implications of IAEA’s guidance in its General Safety Guide No. 8 (GSG-8), which requires that the benefits of a given process outweigh the harms for individuals and societies.

The experts also recommended the alternative method of using the treated water to manufacture concrete for the construction industry instead of releasing it to the sea. By immobilizing the radionuclides in a material, this alternative would imply a lower potential for human contact and would avoid transboundary impacts. Quoted in a National Geographic article, one of the panel members, Robert Richmond, director of the Kewalo Marine Laboratory of the University of Hawaii, summarizes well the uncertainty surrounding the impacts of TEPCO’s water release plan on the ocean environment: “It is a trans-boundary and trans-generational event” and that he does not believe “the release would irreparably destroy the Pacific Ocean but it does not mean we should not be concerned.”

Lack of public trust. In addition to scientific debate, TEPCO’s ALPS treated water issue has become more of a social and political controversy. The origin of this debate was the speech given by then-Prime Minister Shinzo Abe before the International Olympic Committee on September 7, 2013, in which he referred to the city where the 2020 Summer Olympics were to be held by saying: “Some may have concerns about Fukushima. Let me assure you, the situation is under control. It has never done and will never do any damage to Tokyo.” After Abe’s speech, the government took over the responsibility for the management of the contaminated water, while TEPCO is still responsible for all decommissioning operations at the Fukushima Daiichi nuclear power plant. Since then, all policy decisions about the treated water have been made by the Japanese government, with TEPCO simply following the government, which has complicated the decision-making process.

In August 2015, the Japanese government and TEPCO promised to the local fishermen that they “will not implement any disposal without understanding of interested parties.” The government even established a committee consisting of experts from a local university to discuss technical options and held meetings with local citizens for several years to build trust with the local communities. So, when the decision was made by former Prime Minister Yoshihide Suga in August 2021 to release the “treated water” to the sea, this felt like a treachery for the local fishermen and many other interested parties. In a June 2023 statement opposing the planned discharge of treated water, the head of Japan’s national fisheries cooperatives Masanobu Sakamoto said: “We cannot support the government’s stance that an ocean release is the only solution. … Whether to release the water into the sea or not is a government decision, and in that case we want the government to fully take responsibility.”

The subsequent lack of public trust in TEPCO and Japan’s Ministry of Economy, Trade and Industry has been one of the major reasons for this continued controversy. In August 2018, a news investigation revealed that the “tritiated water” still contained other radioactive nuclides after treatment, which were above regulatory standards—a result that was not consistent with the explanation given by TEPCO. The justification then advanced by the ministry and TEPCO on the need and timing for the water discharge was no more convincing: They claimed that there would be a need for storage space once the melted fuel debris would be taken out of the reactors and that, without discharge now, the plant’s storage area would be filled soon. But, the timing—and even the feasibility—of removing the fuel debris is not known at all. Besides, there are potential storage space available at the nearby Fukushima Daini nuclear power plant.

[…]

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＜ふくしま作業員日誌・56歳男性＞高線量の現場　まだ多くある　福島第1原発　via 東京新聞

Posted on 2023/11/17 by nfield

2023年10月27日 12時00分

[…]

春以降、現場の関係で被ばく線量が高くなって「これじゃあ、年度末の3月までもつかどうか…」と心配していたが、何とかなりそうだ。このままではみんな現場にいられなくなると、上の方に直談判してやり方が変わった。高線量の現場では遠隔やロボット作業など、現場に行かなくてできるように工夫されているけれど、作業によっては人がいかないとできない。

　事故直後と違って、今は作業員の被ばく線量は、年間20ミリシーベルト未満で管理されていて、それを万が一でも超えないために、東電から作業を請け負う元請け企業は、8掛けの約16ミリシーベルトを上限としている。それに近づくと、俺らは現場を離れなくてはならなくなる。

　高線量の現場では、1日の計画線量（被ばく上限）の設定が0.8や1ミリシーベルトだが、高いところでは2ミリシーベルトのときもあるという。さすがに事故直後のように3ミリシーベルトとか5ミリシーベルトなどはないけれど。そういう現場は人の入れ替わりが激しい。線量の低い現場と組み合わせて、どこの下請けも被ばく線量を記した名簿をにらみながら人繰りを工夫しているけど、技術や経験が必要な作業はどうしても特定の人に集中する。

　核燃料取り出しのための原子炉建屋やその周辺の作業や調査とか、汚染水を扱う現場やがれきが残る場所など、高線量の現場はいくつもある。単身赴任で来ているから、家族の元に帰って一緒に暮らしたいという気持ちもあるけど、子どもたちも大きくなったし、まだ作業があるから、ここで頑張りたい。（聞き手・片山夏子）

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何が何でも再稼働だから？　東海第2原発の「不備」を4カ月も黙っていた日本原電と原子力規制庁の不誠実　via 東京新聞

Posted on 2023/11/17 by nfield

　首都圏唯一の原発、日本原子力発電東海第2原発で、防潮堤の施工不良が明らかになった。ただ原電の公表は不備の把握から4カ月後。原子力規制庁もかねて報告を受けていたのに、公表に動かなかった。立地自治体の茨城県東海村ではこの間、休止続きの東海第2の再稼働について議会が初めて賛意を示した。原発不信を招く話が伏せられるうちに再稼働の道筋が付く—。こんな話がまかり通っていいのか。（宮畑譲、山田祐一郎、長崎高大）

◆再稼働準備の工事中　「防潮堤」に施工不良

　「すぐに公表しないで、村議会議員や首長にも黙っていたことが問題。命と環境を守る意識が欠けている。信頼関係が崩れた」

　今月8日に開かれた東海村議会の全員協議会。原電の面々を前に、再稼働に反対する阿部功志村議（無所属）はそう糾弾した。

　大名おおな美恵子村議（共産）も「（防潮堤の不備は）重大な工事の失敗。少なくとも県や村、議会には報告してから対策するのが本来の姿だ」と切り出した上で、「全国の人が注目している。住民、地元議会、自治体にはいち早く説明していくスタンスが大事だ」と言葉を重ねた。

　東海第2原発は2018年、原子力規制委員会による新規制基準の審査に通過。同年に運転期限となる40年を迎えたが、最長20年の運転延長が認められた。

その後、防潮堤の建設や非常用電源の設置など事故対策工事を進め、24年9月の完了を経て再稼働に向かう算段だった。

　そんな最中の今年10月、防潮堤に施工不良があったと原電は発表した。

　不備が見つかったのは、防潮堤の取水口付近の鋼製防護壁を支える基礎部分。外周部の地中に埋められた2本の柱（幅15.5メートル、長さ50メートル）の一つに、コンクリートの充填じゅうてん不足による隙間や鉄筋の変形があった。

◆事実の発表は、内部告発を受けた記者会見とまさかの同日

　当然ながら施工不良は問題だが、村議たちは公表の時期にも疑問のまなざしを向けた。原電が施工不良を見つけたのは今年6月。10月までの約4カ月間、公表していなかった。

原電の広報担当者は東京新聞「こちら特報部」の取材に「初めから公表する方向で調整していたが、原因を推定するのに時間がかかった。大方の原因が分かり、発表できるようになったのが10月だった」と説明する。

　ただ、不可解な経緯もある。先の大名村議は9月6日に工事関係者から内部告発を受け、同月22日には原電に質問書を出した。ところがその後に回答がなく、10月16日に会見を開こうとしたところ、原電も同じ日に公表したという。

　原電の担当者は「共産党は関係がない」と語るが、大名村議は「もっと早く公表できたはずだ。公表するつもりはなかったが、会見が入ったので公表したのではないか」といぶかる。

◆山中伸介・規制委員長「重大性がある問題と認識していない」

[…]

10月18日の定例会見で規制委の山中伸介委員長は「現時点で規制委が取り上げるほど重大性がある問題と認識していない」と述べ、「適切な工事がなされれば使用前検査できっちり確認していく」と繰り返した。

　改めて規制庁に聞くと、担当者は「法令に基づき報告を義務付けている事象がある。今回の施工不良は該当せず、われわれから公表するものではない。あくまで完成後に検査をして合否を判定する」と述べ、「立地自治体への説明は大事なことだが、事業者が行うべきこと。コメントする立場にはない」と話した。

◆日本原電と原子力規制庁の置かれた立場は

　首をかしげたくなる対応を取る原電と規制庁。両者に関していえば、東海第2原発の再稼働に前のめりな姿勢がうかがえる。

　原電は原発専業の電力会社だが、保有する敦賀原発1、2号機（福井県）、東海第2原発のうち、敦賀1号機は廃炉が決定。直下に活断層がある2号機も再稼働に向けた審査が滞る。震災以降、販売電力量はゼロで、再稼働を前提に原発の維持や管理費の名目で電力各社が支払う「基本料金」で経営をつなぐ。

[…]

◆知らされない間に東海村議会が「再稼働求める請願」採択

　国策と化す再稼働を巡っては、防潮堤の施工不良が公表されずにいた間、東海第2が立地する東海村では重要な局面を迎えていた。

　村議会原子力問題調査特別委員会は9月、村商工会などが出していた再稼働を求める請願を賛成多数で「採択するべき」とした。再稼働を巡って議会が事実上の賛意を示すのは初めて。再稼働に反対する請願は「不採択」とした。

　ただ施工不良が公表されていれば、委員会での審議に影響を与えた可能性がある。10月の公表でよかったのか。原電は「原因を一定程度推定するのに時間がかかった。村の請願とは関係ない」と答える。

脱原発を訴える市民団体「たんぽぽ舎」の柳田真共同代表は「原電はこれ以上、工事を遅らせることはできず、情報を伏せたのでは。何が何でも来年9月に工事完了できるよう躍起なのだろう」と推し量る。

　一方、茨城大の蓮井誠一郎教授（国際政治学）は「不備をすぐに公表しなかったのは地域や社会をどこか信頼しておらず、オープンな議論を避けた結果ではないか」といぶかる。

◆炉心溶融事故が起きたら経済的な損失は660兆円

　厳しい視線は村議会にも向く。防潮堤が完成していない段階で再稼働絡みの請願の審議を進めたほか、不備が発覚した後も再審議に動かなかったからだ。

　「地域のリスクを軽視しており、チェック機能が果たされていない」

　再稼働に前のめりになるあまり、安全面がないがしろにされては困る。

　東海第2で事故が起きれば甚大な被害が生じかねない。環境経済研究所の上岡直見代表は「炉心溶融事故が起きた場合、経済的な損失は660兆円を超える」と試算する。

　福島第1原発2号機の放射性物質放出量の推定値と同量が東海第2から大気中に放出された場合、東京23区の東半分までの住民が避難や一時移転を余儀なくされ、生産・消費活動が停止すると想定した。

　福島の事故では、民間シンクタンクが事故処理費用が最大81兆円に及ぶと試算した。「条件設定にも左右され、直接比較はできない」と語る一方、「再稼働した場合、利益と比べて桁違いのリスクがある。原電はどこまで認識しているのか」とも指摘する。

[…]

◆デスクメモ

　2020年9月の柏崎刈羽原発。東京電力はテロ対策の不備を把握し、規制庁に伝えたが、公表されなかった。表沙汰になったのは翌年1月の報道。その間、再稼働が絡む規制委の審査があり、ゴーサインが出た。「またか」と思う今回の件。双方に絡む規制庁。不信ばかりが募る。（榊）

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