Japan Nuclear Overview

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The U.S. use of nuclear weapons on Hiroshima and Nagasaki in 1945 toward the end of World War II marks the only time nuclear weapons have been used in war. This experience significantly shaped Japan’s nuclear policy. Japan is a member and strong proponent of all the nuclear nonproliferation treaties and regimes, and has never developed a nuclear weapons program of its own.

Japan’s nuclear disarmament and nonproliferation policy is comprised of four pillars:

1. The Atomic Energy Basic Law of 1955-,which restricts Japan’s nuclear energy use exclusively to peaceful purposes;
2. The “Three Non-Nuclear Principles” adopted in 1968 by the Japanese Diet, in which Japan pledges not to manufacture, possess, or permit the introduction of nuclear weapons onto Japanese soil;
3. Tokyo’s compliance with the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) and its active participation in strengthening the NPT regime; and
4. Tokyo’s reliance on the U.S. extended nuclear deterrent.

Despite Japan’s long-standing stance against nuclear weapons, there was an internal debate in the late 1960s through the early 1970s about whether Japan should sign the NPT, in part due to concerns about assuring access to nuclear technology to meet national energy needs, and the discriminatory nature of the treaty. Some conservatives were also concerned that closing off the nuclear option might negatively impact future national security needs. In 1968, then Prime Minister Sato commissioned a secret nongovernmental study on the costs and benefits to Japan of developing nuclear weapons capabilities. The existence of this report was leaked to the public in 1994. The report concluded that nuclearization would negatively affect Japanese security and that the U.S. extended nuclear deterrent would be sufficient. ¹

At Japan’s parliamentary elections in December 2012, the opposition Liberal Democratic Party (LDP), which had ruled Japan for nearly half a century until 2009, returned to power with a landslide victory in the lower house of Japan’s national Diet over the ruling Democratic Party of Japan (DPJ). While the political changes have brought to light the differences between the two parties’ concerning Japan’s post-Fukushima nuclear energy policies, no significant change in disarmament and nonproliferation policy has been observed.

Before the DPJ came to power in 2009, the LDP was in the process of preparing the country’s new National Defense Program Guidelines (NDPG), presumed to include a more assertive security policy. However, due to the political power shift, the DPJ postponed the adoption of the NDPG until the end of 2010 for further consideration. The 2010 NDPG, the first one published under the DPJ government, introduced a major shift in the country’s strategic concept from “basic defense force” to “dynamic defense capability” in response to a rapid transformation of the security environment in the region. These included the increasing threats posed by North Korea’s nuclear and missile programs, and concerns over China’s military modernization and naval activities in the East China Sea. ² However, Japan’s nuclear nonproliferation and disarmament policy remained the same under the DPJ government, namely that “Japan will play an active role in international nuclear disarmament and nonproliferation efforts, and will continue to maintain and improve credibility of U.S. extended deterrence, with nuclear deterrent as a vital element, through close cooperation with the U.S.” ³

While no significant change was observed in Japan’s nuclear disarmament policy under the DPJ government, then-DPJ Foreign Minister Katsuya Okada ordered a probe into the secret agreement between Japan and the United States concluded in 1969 that allowed the United States to bring nuclear weapons into Okinawa in case of emergency. Under the earlier LDP administrations, the existence of the secret agreement had been denied for decades. ⁴ Given that this secret agreement contradicts one of the Three Principles, non-introduction of nuclear weapons to Japan, the issue of the Three Non-Nuclear Principles was rekindled when the existence of the secret agreement was ascertained by the DPJ government.

During the preparation period of the 2010 NDPG, debates over the Three Non-Nuclear Principles, and particularly the third principle of non-introduction, intensified. In the past, hawkish politicians and scholars often advocated reconsidering the non-introduction principle, although successive Prime Ministers have expressed their official support for it. An expert panel, which was formed to prepare the 2010 NDPG, submitted its final report in August 2010, including several recommendations. The panel recommended that Japan maintain its Three Non-Nuclear Principles, notwithstanding some speculation that it would recommend reconsideration of the non-introduction principle. ⁵ As expected, the 2010 NDPG stipulated, “Japan will continue to uphold …the Three Non-Nuclear Principles.” ⁶ Despite sporadic debates over the issue of non-introduction, for the foreseeable future it is highly unlikely that Japan will change the Three Principles.

After the LDP and its junior coalition partner, the New Komei Party, won a comfortable majority in the Upper House election in July 2013 that enabled the coalition to rule both Houses of the Diet, Prime Minister Abe set the stage for his long-standing goal to strengthen national security and to be more assertive in international security and diplomacy. ⁷

The Japanese government launched the National Security Council on 4 December 2013, and adopted the first ever National Security Strategy to cover Japan’s security policies for the next 10 years. The government also issued its new National Defense Program Guidelines. As expected, the new defense policy presents more assertive and “proactive pacifism” as the Prime Minister repeatedly emphasized. ⁸ It also stressed Japan’s dedication toward countering the threat of North Korea’s nuclear weapons program, promising to increase cooperation with the United States over extended deterrence, ballistic missile defense and “protection of the people.” ⁹

As for its nuclear policy, the new policy documents affirm that Japan continues to play an important role in nuclear disarmament and nonproliferation. With regard to the threat of nuclear weapons, Japan continues to maintain and improve the credibility of extended deterrence provided by the United States and ballistic missile defense (BMD). ¹⁰

In one of the largest shifts in Japan’s security policy since the end of World War II, on 19 September 2015, Japan’s parliament enacted a legislative package that would permit Japan’s Self Defense Forces to engage in collective self-defense, the goal that has been pursued by Prime Minister Abe. While the degree of the engagement in collective self-defense is significantly limited mainly because of LDP’s junior coalition partner, the New Komei Party’s efforts to maintain the exclusively defensive nature of Japan’s security policy, this deliberation process generated heated debates both inside and outside of the National Diet with concerns that Japan might abandon its pacifist security policy. ¹¹

Japan’s commitment to nuclear disarmament and nonproliferation and its support for the NPT have remained unchanged since it acceded to the treaty in 1976. Tokyo has been further intensifying its efforts toward strengthening multilateral nonproliferation and disarmament regimes since the early 1990s. These efforts reflect a shift in its foreign policy after the Cold War in which Tokyo has been increasingly emphasizing the importance of international cooperation on disarmament and nonproliferation, and actively participating in efforts to strengthen international peace and security. Japan has submitted disarmament resolutions to the United Nations General Assembly every year since 1994, and ratified the Comprehensive Nuclear Test Ban Treaty (CTBT) in 1997 while pushing for its early entry into force. Japan has also strongly supported a Fissile Material Cut-off Treaty (FMCT). ¹² Japan’s Hiroshima and Nagasaki experiences, coupled with its highly developed technology sector and an economy which enables it to commit resources to international nonproliferation and disarmament efforts, have uniquely situated it to uphold and promote the principles of nuclear nonproliferation and disarmament. In particular, Tokyo has actively promoted disarmament and nonproliferation education since the United Nations General Assembly endorsed the Secretary General’s report on the UN Study on Disarmament and Nonproliferation Education in November 2002. ¹³

In 2008, Japan and Australia established the International Commission on Nuclear Non-Proliferation and Disarmament (ICNND) to reinvigorate international nonproliferation and disarmament efforts, and to help shape a consensus at the then-upcoming 2010 NPT Review Conference. ¹⁴ The ICNND’s final report, containing 76 recommendations, was issued in December 2009. ¹⁵ While the report does not represent the official policy of Japan or Australia, the two governments are closely working together to promote nuclear disarmament and nonproliferation. They have reached out to non-nuclear weapon states to form an alliance to further promote disarmament and nonproliferation. As part of these efforts, the two countries launched the Non-Proliferation and Disarmament Initiative (NPDI) with eight other countries, including Canada, Germany, Mexico, Turkey, Chile, the Netherlands, Poland, and the United Arab Emirates. Two more countries, Nigeria and the Philippines, joined the NPDI at its seventh ministerial-level meeting held on the sidelines of the United Nations General Assembly on 24 September 2013. ¹⁶ The NPDI has held eight ministerial-level meetings in September 2010, April 2011, September 2011, June 2012, September 2012, April 2013, September 2013, and April 2014 in New York City, Berlin, New York City, Istanbul, New York City, the Hague, New York City and Hiroshima, respectively. ¹⁷ Each meeting adopted a ministerial statement urging, among other things, the immediate commencement of FMCT negotiations, early entry into force of the CTBT, concrete progress in nuclear disarmament, and the universalization of the IAEA Additional Protocol. ¹⁸

Despite these concrete disarmament initiatives, Japan is often criticized for its relatively reticent approach to the vision of a world without nuclear weapons. At the first session of the Preparatory Committee (PrepCom) for the 2015 NPT Review Conference, 16 countries issued a joint statement on the humanitarian dimension of nuclear disarmament in May 2012. ¹⁹ However, Japan was not a sponsoring country, which triggered debates over Japan’s role in nuclear disarmament, especially among civil society advocating nuclear disarmament. Furthermore, the Japanese government officially expressed its refusal to be a sponsor of the joint statement on the same topic at the UN General Assembly First Committee in the same year, while 34 other countries sponsored the statement. ²⁰ This drew further criticism from disarmament advocates both inside and outside of Japan. The reason why the Japanese government did not endorse the statement is that parts of the statement were not completely congruent with Japan’s national security policy that relies on U.S. extended nuclear deterrence. ²¹ After facing increasing criticism and protests from civil society both inside and outside of Japan against Tokyo’s refusal to sign the statement at the second session of the PrepCom for the 2015 NPT Review Conference, where more than 80 countries signed, the Japanese government enhanced its diplomatic efforts to make the statement’s wording consistent with Japan’s national security. ^{22 23} At the 68th UN General Assembly in 2013, for the first time, Japan decided to join the statement along with 124 other countries. ²⁴

Since then, Japan continues to be a co-sponsor of the humanitarian statement at the 2014 UN General Assembly and the 2015 NPT Review Conference. However, Japan has not signed the “Humanitarian Pledge” that was initiated by the Austrian government at the Third International Conference on the Humanitarian Impact of Nuclear Weapons in Vienna in December 2014. The Pledge calls for creating a new legal framework to prohibit nuclear weapons. ²⁵

These divided views toward a world free of nuclear weapons were accentuated at the 71st session of the United Nations General Assembly First Committee, when Japan voted against the draft resolution “Taking forward multilateral nuclear disarmament negotiations” along with most of NATO countries and other U.S. allies. ²⁶ While Japan usually abstained from such resolutions, this is the first time that Tokyo voted against. It is reported that the U.S. government urged NATO countries and Japan to vote against that resolution instead of abstention. Responding to criticism mainly from disarmament advocates in Japan, Foreign Minister Fumio Kishida explained that the resolution did not match Japan’s stance to pursue a world free of nuclear weapons through concrete and pragmatic measures. He also emphasized that nuclear deterrence is necessary in the midst of the growing threats posed by North Korea’s nuclear and missile development. In addition, he expressed his concern that the resolution further deepens the division between nuclear weapon states and non-nuclear weapon states. ²⁷

Japan’s official policy does not support negotiating a nuclear weapons convention to prohibit nuclear weapons. Japan, along with some U.S. allies, endorses what it views as more practical and realistic methods to reduce nuclear threats.

Japan boycotted the 2017 United Nations Conference to negotiate a nuclear ban treaty. ²⁸ The Japanese delegation came to the conference only on the first day to explain why Japan would not participate in the negotiations, arguing that efforts toward a nuclear ban that failed to engage the nuclear weapon states would only deepen the schism between states and delay the goal of a world free of nuclear weapons. ²⁹

Japan’s decision not to participate in the negotiations generated tremendous disappointment with some groups, and especially among the survivors of the 1945 nuclear attacks on Hiroshima and Nagasaki, known as the Hibakusha. Many believed that Japan, as the only country to have experienced nuclear attacks during war, had a moral responsibility to lead efforts to accomplish a world without nuclear weapons. ³⁰

As part of efforts to build bridges between parties with opposing views, the Japanese government established the “Group of Eminent Persons for Substantive Advancement of Nuclear Disarmament,” and submitted its recommendations to the second session of the PrepCom for the 2020 NPT Review Conference. ³¹

Japan’s security relationship with the United States has tempered Tokyo’s emphasis on disarmament, as Japan remains a beneficiary of U.S. extended nuclear deterrence. Despite its intensified nonproliferation and disarmament efforts since the 1990s, Tokyo’s two seemingly contradictory nuclear weapons-related policies have complicated its efforts to champion nuclear disarmament. Japan’s National Defense Program Guidelines state, “Against the threat of nuclear weapons, rely on the U.S. nuclear deterrent, while working actively on international efforts for realistic and steady nuclear disarmament aiming at a world free from nuclear weapons.” ³² Critics often assert that such a statement represents the Japanese government’s ultimate dilemma. However, as long as nuclear weapons threats exist, Japan’s official stance acknowledges that both disarmament and extended deterrence are necessary to enhance its national security.

Increased U.S. and international interest in the nuclear disarmament process has therefore created mixed feelings in Japan, where stronger commitment to nuclear disarmament is welcomed on the one hand, while there is a cause for concern about the U.S. extended deterrent commitment on the other. In July 2009, the U.S. and Japan set up an official framework to conduct periodic dialogues, including issues such as extended nuclear deterrence, in which the United States reiterated its commitments to Japan. ^{33 34} Contrary to Tokyo’s official policy, both mayors of Hiroshima and Nagasaki in their Peace Declarations urged the Japanese government to pursue security without relying upon U.S. extended nuclear deterrence. ³⁵

Japan has an advanced civilian nuclear sector. Prior to March 2011, Japan increasingly relied on nuclear power for its electricity needs. With almost no indigenous energy sources, Japan’s nuclear energy accounted for over 30% of the country’s total electricity production. Japan had planned to increase this to 40% by 2017, and 50% by 2030. Japan had 54 nuclear power reactors in operation across the country (the third largest number in the world, after the United States and France). Japan was in the process of constructing two new reactors, and had been planning to construct 11 additional power reactors before March 2011. ³⁶

However, the Great East Japan Earthquake that devastated the Tohoku region in Japan on 11 March 2011 caused a catastrophic nuclear accident at the Fukushima Dai-ichi Nuclear Power Station of Tokyo Electric Power Co. (TEPCO), and as a result significantly affected Japan’s nuclear energy policy and public opinions of nuclear energy. In the wake of the Fukushima accident Japan’s nuclear energy policy underwent a comprehensive review, and all of the new plant constructions have been halted.

One of the most notable developments in Japan’s nuclear energy policy since the Fukushima accident was the decision by the Japanese government to establish a new agency in charge of nuclear safety under the Environment Ministry, given acute criticism that its old system failed to appropriately and effectively respond to, or even prevent, the nuclear crisis. The old regulatory agency, the Nuclear and Industrial Safety Agency, was under the Ministry of Economy, Trade, & Industry, which promotes nuclear energy. The new regulatory agency, the Nuclear Regulation Authority, was established in September 2012, combining safety and regulatory functions that are completely separated from those parts of the government responsible for promoting nuclear power. ³⁷

As a result of the post-Fukushima nuclear policy review under the new LDP government, the government adopted the 4th Basic (or Strategic) Energy Plan, proposed by the Ministry of Economy, Trade and Industry (METI). The plan calls nuclear power “an important base-load power source as a low carbon and quasi-domestic energy source,” expresses the Japanese government’s commitment to restarting nuclear power plants, and reiterates the need to reduce radioactive waste through reprocessing of spent fuels and effective use of plutonium. ³⁸ The plan also supports the completion of the Rokkasho spent fuel recycling plant. Unlike previous plans, the 4th Basic Energy Plan does not disclose a specific target nuclear energy ratio, although it does provide a ratio for “self-motivating energy.” On 1 June 2015, the Advisory Committee on Energy and Natural Resources under METI approved the draft report including the plan to set a share of 20% to 22 % for nuclear power in Japan’s energy mix by 2030. ³⁹ As for the number of Japan’s operable nuclear power reactors, five older reactors in different areas were announced for retirement in April 2015. This decreases the total number of operable nuclear power reactors in Japan to 42. ⁴⁰

After two years of all of Japan’s nuclear power reactors standing idle, on 10 September 2015, Japan restarted unit 1 of the Sendai nuclear power plant in Kagoshima prefecture of the Kyushu Electric Power Company. ⁴¹ This restart is the first to be approved under the new upgraded safety standards after the Fukushima accident. ⁴² Following this initial restart, unit 2 of Sendai also became operational on 17 November 2015. ⁴³

Kansai Electric Power Company’s Takahama units 3 and 4 restarted in January and February. However, just a few days after the restart of unit 4, the reactor shut down due to technical problems. ⁴⁴ Moreover, on 9 March 2016, two days before the five-year anniversary of the Fukushima disaster, the Otsu District Court in Shiga Prefecture, part of which lies within 30 kilometers of the Takahama plant, issued an injunction to halt operations at units 3 and 4 given local residents’ concerns over the safety of the plants. Both Takahama units 3 and 4 are using MOX fuel. ⁴⁵

This court injunction dealt a blow to the government’s pro-nuclear energy policy in the midst of public anti-nuclear sentiment. It is still uncertain how many nuclear reactors will restart in the next few years. ⁴⁶ However, ion March 2017, the Osaka High Court lifted the injunction that kepton units 3 and 4 of the Takahama plant offline for the previous year, agreeing with the utility that both units were safe to operate. Following Following this court decision, unit 3 and unit 4 started commercial operation on July 4, and June 16, 2017 respectively. ^47 48

Shikoku Electric Power Company’s Ikata unit 3, which uses MOX fuel, resumed commercial operations on September 7, 2016. Unit 3 of the Ohi nuclear power plant of the Kansai Eclectic Power Company resumed commercial operation in April 2018. With the two Takahama reactors using MOX fuel, Japan currently has three units running on MOX fuel. ⁴⁹

The Current Status of Fukushima

Nearly a decade after the accident, one of the most serious concerns related to the Fukushima crisis is the leakage of radiation-contaminated water from the power plant. In December 2014, all radioactive fuels were removed from unit 4 of the Fukushima Daiichi Station. The removal of the fuel from the remaining three units will be the priority, while it is expected to take 30 to 40 years to complete the decommissioning process. ⁵⁰ The damaged nuclear power reactors and two surviving units are subject to decommissioning by TEPCO. ⁵¹

Backend of the Nuclear Fuel Cycle

Japan has a controversial program for recycling spent nuclear fuel that has produced large quantities of plutonium in the form of metal-oxide nuclear fuel. ⁵² By the end of 2016, Japan possessed 46.9 metric tons of separated plutonium; 9.8 metric tons within the country, and 37.1 metric tons at reprocessing plants in Britain and France. ⁵³ All of the nuclear fuel stockpile is currently slated to return to Japan for use in domestic nuclear facilities. The original plan called for consumption of the stored fuel by 2010, but due to technical and safety issues, this timetable has been delayed, and the return of the stored fuel to Japan is proceeding slowly. Some argue this material could provide Japan with a latent nuclear weapons capability. Because of this, in an effort to enhance the transparency of Japan’s plutonium stockpile, the Japan Atomic Energy Commission (JAEC) decided in 1991 to annually declare Japan’s plutonium stockpile by location. In addition, JAEC officially adopted a policy of “no surplus plutonium” in 1994. The Japanese government reiterates this policy on occasion. On 24 March 2014 Prime Minister Abe stated at the 2014 Nuclear Security Summit that Japan will “possess no plutonium reserves without specified purposes,” paying careful attention to managing plutonium reserves. ⁵⁴

Japan’s strong commitment to the development of a self-sufficient plutonium-based nuclear fuel cycle led to the construction of the Rokkasho spent fuel recycling complex in Aomori Prefecture (Northernmost prefecture of Japan’s Main Island), and the Monju prototype fast-breeder reactor in Fukui Prefecture. Originally, Japan was planning to use MOX fuel in fast breeder reactors. However, Monju has continued to encounter problems including the sodium leakage accident in 1995. In 2010 it encountered another accident and the reactor has been shut since that time. ⁵⁵

The Rokkasho reprocessing plant will be the first commercial nuclear fuel reprocessing plant in Japan, and the first one in an NPT non-nuclear weapon state. Despite strong domestic and international criticism and opposition, the reprocessing plant started active testing on 31 March 2006. Once the reprocessing plant moves beyond the testing phase to become commercially operational, it will separate and stockpile up to eight metric tons of plutonium annually. This amount would be enough to produce 1000 nuclear weapons. The Rokkasho reprocessing plant was originally scheduled to become operational in November 2008, a date subsequently pushed back to October 2010. ⁵⁶ However, complications during test operations caused Japan Nuclear Fuel Ltd. to postpone this date multiple times. Since the Nuclear Regulation Authority required all the nuclear fuel cycle facilities to be compliant with the new safety standard, the JNFL changed the planned start date from October 2013 to “to be announced.” On 18 December 2013, the Nuclear Regulation Authority put in place new regulations on nuclear fuel cycle facilities, and the JNFL applied for safety assessments of its reprocessing plant on January 7th. ⁵⁷ The JNFL had aimed to start plant operation in October 2014, expecting the assessment by the NRA to be completed in about six months. ⁵⁸ However, in December 2017, the JNFL announced further delays to completion of the Rokkasho reprocessing plant due to additional regulatory requirements. It is now scheduled for completion in the first-half of fiscal year 2021. Completion of the reprocessing plant has been delayed more than 20 times. ⁵⁹

The problem of Japan’s plutonium stockpiles continues to be an international concern, especially since the country was found to have understated its stockpile of mixed plutonium-uranium oxide (MOX) fuel by about 640 kilograms in its 2012 and 2013 reports to the IAEA. ⁶⁰ 80 nuclear bombs could be created from this amount of material. Japanese officials from the Japan Atomic Energy Commission claimed the understatement was valid because the fuel was being stored in a non-operational reactor. However, former IAEA Deputy Director Olli Heinonen argues the unirradiated material should have been reported “regardless of its location.” Japan is facing criticism on the issue from both domestic and international actors, and particularly from China. ⁶¹

As part of efforts to mitigate international concern and enhance nuclear security, the United States and Japan are jointly working to reduce weapons-usable nuclear materials.

On 24 March 2014, at the Nuclear Security Summit in the Netherlands, Japanese and U.S. officials concluded a bilateral agreement by which Japan will send weapons-grade plutonium and highly enriched uranium from the Japan Atomic Energy’s Fast Critical Assembly to the U.S., where it will be converted into “non-sensitive materials.” ⁶²

The U.S. also promised to aid in Japanese research on a disposal solution for nuclear waste. Almost two years after this agreement, at the final Nuclear Security Summit that was held in Washington DC on 31 March – 1 April 2016, the two countries announced that all highly enriched uranium (HEU) and separated plutonium fuel has been removed from the FCA. Furthermore, the two countries announced that they agreed to work together to remove all HEU fuel from the Kyoto University Critical Assembly (KUCA) to the United States in order to convert the HEU to LEU. ⁶³ On 22 March, the 331 kg of weapons grade plutonium from the FCA left for the United States Department of Energy’s Savannah River Site in South Carolina by a British nuclear fuel carrier. ⁶⁴ The plutonium from Japan was sent to the Savannah River Site despite objections from the state of South Carolina, and it will eventually be placed at the Waste Isolation Pilot Plant in New Mexico.

While this pact is an important step toward nuclear security and disarmament, the plutonium that was removed from the Fast Critical Assembly constitutes only 3.5 percent of Japan’s domestic stockpile, and does not address the plutonium that may be produced by the Rokkasho plant. ⁶⁵

Currently, there is no prospect for commercialization of a fast breeder reactor, and the prospect of burning MOX fuel in conventional light water reactors (pluthermal cycle) is bleak.

The government decided to thoroughly review the Monju prototype fast breeder reactor on 21 September 2016. The government announced that an expert panel to discuss Japan’s fast reactor development policy would be launched, and the fate of the Monju reactor would be discussed there. ⁶⁶

After conducting four meetings, the expert panel decided to discontinue the Monju project, and the Inter-Ministerial Council for Nuclear Power formally announced that decision on 21 December 2016. The Japanese government invested more than one trillion yen, (approximately 8.5 billion U.S. dollars) in research and development for Monju in the hopes that it would play a central role into Japan’s closed nuclear fuel cycle. According to the government’s calculations, it would cost at least 375 billion yen (approximately 3.2 billion U.S. dollars) over 30 years to fully decommission the facility. ⁶⁷

Although the Japanese government decided to scrap Monju, it decided to continue research and development of fast reactors with an aim to complete the country’s nuclear fuel cycle program. This decision was made according to Japan’s Basic Energy Policy that was approved by the Cabinet in April 2014. It states that the nuclear fuel cycle continues to be an essential part of the country’s nuclear energy policy. The government decided to establish a strategic working group to complete a “roadmap” for development of a demonstration fast reactor by 2018. ⁶⁸

With the decision to scrap Monju, and most of Japan’s nuclear plants having been idle since the Fukushima accident in March 2011, there is no concrete plan to utilize accumulated plutonium. Nevertheless, the Japanese government largely decided to continue its current nuclear fuel-cycle policy, including a stated policy of reprocessing all the spent fuel from nuclear power reactors. ⁶⁹ Japan’s stockpile of excess plutonium concerns both neighboring countries and the United States.

While some uncertainty remains regarding Japan’s nuclear fuel cycle policy, it has become clearer that the current Japanese government is determined to continue reprocessing of spent nuclear fuel despite concerns both inside and outside of the country. In July 2015, METI initiated discussions by a panel of experts to ensure continuation of the nuclear fuel cycle project. ⁷⁰

In February 2016, the Japanese Cabinet approved the new bill to amend the part of “the Spent Nuclear Fuel Reprocessing Fund” with an aim to take necessary measures for the steady implementation of the reprocessing of used nuclear fuel by creating a new government-backed entity responsible for reprocessing and introduce a new system for funding it. The bill was enacted into law by Japan’s parliament in May 2016. Accordingly, the new government-backed entity replaced the Japan Nuclear Fuel Limited, which was in charge of Japan’s nuclear fuel cycle facilities’ operations. The new entity, the Nuclear Reprocessing Organization of Japan, was established on 3 October 2016, in Aomori city. The organization plans to set up a representative office in Rokkasho, where JNFL has facilities for reprocessing. ⁷¹

Anti-nuclear sentiment among the Japanese public has far outweighed support for keeping a nuclear weapons option open. It has long been considered taboo for Japanese officials to argue in favor of the possibility of a nuclear weapons option.

Nevertheless, several neighboring countries have expressed concerns about possible Japanese nuclear ambitions due to Japanese officials’ occasional nuclearization debates. Recent tension developing in the region, particularly on the Korean peninsula, has led to increased discussions in Japan about the once-taboo subject of nuclear weapons development, including comments by high-ranking officials on the possibility of amending the three non-nuclear principles in 2002. Most recently, after North Korea conducted its nuclear weapon test in October 2006, high-ranking Japanese officials made some comments advocating that the debate over developing nuclear weapons should not be prohibited. It appears that the threshold for the debate of nuclear weapons in Japan has been lowered. ⁷²

Still, despite speculation that Japan may reconsider its nuclear options, the Japanese public’s deep aversion to nuclear weapons and Tokyo’s strong commitment to international nonproliferation regimes make any move in this direction unlikely.