1. Classification of Radioactive Waste
Radioactive waste is produced at nuclear power plants and nuclear fuel cycle facilities, and also through research, medical and industrial use of radioisotopes (RIs). The main nuclear fuel cycle facilities operating in Japan include a uranium enrichment plant, nuclear fuel fabrication plants, and spent nuclear fuel reprocessing plants. There is also a research and development-level MOX fuel fabrication facility. Construction of a commercial plant is planned. Radioactive waste generated at nuclear power plants and nuclear fuel cycle facilities is regulated under the Act on the Regulation of Nuclear Source Material, Nuclear Fuel Material and Reactors (Reactor Regulation Act) and RIs are regulated under the Act Concerning the Prevention of Radiation Hazards.
Gaseous wastes are released into the atmosphere from the exhaust stack and liquid wastes are released into the environment via waste water pipes, so the disposal of radioactive waste relates to solid waste.
In Japan, radioactive waste is classified either as "high-level" or "low-level". The term "medium-level radioactive waste" is not used in Japan. Japan's policy is to reprocess spent nuclear fuel (the failed "closed nuclear fuel cycle" concept), so the only "high-level radioactive waste" (HLW) will be the vitrified canisters that are produced at the reprocessing plant. Everything else is lumped together into the "low-level radioactive waste" (LLW) category.
LLW is further subdivided into "relatively high", "relatively low" and "extremely low" level radioactive waste. Waste that is even less radioactive than so-called "extremely low-level" waste is exempted from radioactive waste regulations under a "clearance" system. In addition, waste which one would not expect to be contaminated with radioactivity, or which has had radioactive contamination removed, is classified as "non-radioactive waste" and exempted from radioactive waste regulations.
Transuranic Waste (TRU) (waste containing elements higher in the periodic table than uranium, along with other isotopes with long half-lives such as Iodine 129) are classified as "low-level radioactive waste", but it is planned that TRU with a relatively high concentration of radioactivity will be buried deep underground in the same way as HLW.
2. Low-Level Radioactive Waste
The bulk of LLW falls in the "relatively low" sub-category. That portion which is generated at nuclear power plants is buried at the LLW Disposal Center at Rokkasho Village in Aomori Prefecture. This facility is owned by Japan Nuclear Fuel Ltd. (Most of JNFL's shares are owned by the electric power companies.) LLW generated at nuclear fuel cycle facilities (170,000 x 200 liter drums at the end of March 2010) and through the use of RIs (about 560,000 drums at the end of March 2009) have not been disposed of yet. The fuel cycle waste is stored at the facilities where it was generated. RI waste that has been moved from the site where it was generated is stored at one of the two treatment and storage facilities (Tokai Village in Ibaraki Prefecture and Takizawa Village in Iwate Prefecture) and nine other interim storage facilities.
By the end of March 2010, about 220,000 drums had been transported from nuclear power plants to JNFL's Rokkasho facility, while about 650,000 drums were still stored at the nuclear power plants. It is planned that eventually 3 million drums will be disposed of at the Rokkasho facility. The Japan Atomic Energy Agency (JAEA) has been designated as the body responsibly for disposing of RI waste, but no progress has been made on selection of a site. In regard to nuclear fuel cycle waste, it has not yet been decided whether or not the owner of each facility will be responsible for disposal. It is fair to say that the policies for disposal of the various categories of waste are totally disparate and lacking in coherence.
"Relatively low level" LLW is stored in drums and disposed of in concrete pits. A concrete pit is built just below ground level. The drums are piled into the pit and filled in with mortar. It is said that control of the site will gradually be relaxed as the level of radioactivity falls over a 300-year period after the drums are buried, but in fact, after 50 years anyone will be able to approach the site, as long as they don't dig up the drums. It is even said that it could be turned into a children's playground or an apple orchard.
The shallow burial policy for LLW has not always been the preferred option. The original policy was shallow burial, but the policy changed to disposal at sea, before reverting to shallow burial. When the Reactor Regulation Act was established in 1957 it was blithely assumed that shallow burial would be possible, but it became impossible to implement this policy and the word "burial" was deleted from the Act after the International Commission on Radiological Protection (ICRP) recommended in 1959 that there was no threshold below which exposure to radiation was safe.
As a result, storage at each facility has continued for an extended period of time.
In 1980 regulations were prepared to enable experimental disposal in the North Pacific Ocean, but opposition from Pacific island residents stymied these plans. In 1983 dumping at sea was frozen by the Conference of Parties (COP) to the London Convention, so Japan had to abandon this policy. Such dumping was banned completely at COP 1993.
The Reactor Regulation Act was amended in 1986 to once again enable shallow burial. However, for the first 300 years it would be controlled, so for this period, regardless of the actual situation, it would considered to be storage rather than disposal. The first drums of LLW were transported from nuclear power plants to the LLW Disposal Center in Rokkasho at the end of 1992.
"Relatively high-level" LLW from decommissioning of nuclear power plants etc. will be put in drums, or large rectangular containers and buried between 50 and 100 meters underground (so called "disposal at depth"). The control period was set at "a few hundred years". It might seem that this is longer than 300 years, but actually the time has not been specified. It is planned that this waste will also be disposed of in Rokkasho, but as of August 2010 the project had not begun, because local agreement had not yet been obtained.
"Extremely low-level" LLW from decommissioning of nuclear power plants can be disposed of in trenches, simply wrapping it in plastic sheets. The control period is 30 to 50 years. For example, approximately 1,700 tons of concrete from the decommissioning of the Japan Power Demonstration Reactor (JPDR), owned by the former Japan Atomic Energy Research Institute (now Japan Atomic Energy Agency), was put into polyethylene bags and buried in trenches within the grounds of the facility.
The notion of removing controls on radioactive waste that is below a given level of radioactivity was introduced in a 1986 amendment to the Reactor Regulation Act. The concept applied to waste for which the abovementioned control period had elapsed. The amendment was passed on May 21, less than one month after the Chernobyl accident on April 26, 1986.
However, it took 19 years for specific clearance levels to be established under an amendment passed in 2005. This amendment only applies to waste generated at nuclear power plants. A system for clearance of radioactive waste generated at nuclear fuel cycle facilities is currently being prepared. In regard to RI waste, an amendment to the Act Concerning the Prevention of Radiation Hazards was passed in May this year.
Waste below the clearance level (annual dose benchmark of less than 10 micro-sieverts for each isotope) can be disposed of as industrial waste, or reused. However, in the case of reuse, electric power companies voluntarily agreed not to release the material into the general community until the system is well established.
Reuse of metals from decommissioning of the Tokai Nuclear Power Station (GCR, 166 MW) that were assessed to be below the clearance threshold began in 2007. It has been reused in such things as radiation screens in the Japan Proton Accelerator Research Complex (J-PARC) and the legs of benches and tables used in nuclear power plants and their public relations facilities, as well as in the head offices of electric power companies. It is reasonable to say that these uses are for PR purposes to justify the claim that the "system is well established".
The expression "non-radioactive waste" suddenly appeared in 1993. This is waste that is said to be fundamentally not radioactive and therefore not in need of any clearance. It includes those parts of radioactive waste that could not conceivably have been contaminated with radioactivity, or that have had the radioactivity removed. This notion change represented a shift from the view that all waste generated in the "radiation control area" was radioactive waste.
The reason was that as nuclear power plants got older, large items of equipment, such as steam generators, had to be replaced and, as a result of this, unplanned waste was generated, such as from cutting open the containment vessel. With the appearance of this "non-radioactive waste" category, huge quantities of waste arising from decommissioning do not need to be treated as radioactive waste, or be assessed to determine whether they fall beneath the clearance level. The aim is to exempt 98-99% of decommissioning waste from treatment as radioactive waste. The majority of this (94-98%) is so called "non-radioactive waste".
4. High-Level Radioactive Waste
HLW and upper range TRU will be buried over 300 meters underground - so-called "geological disposal". In May 2000 the Specified Radioactive Waste Final Disposal Act was established. At the time specified radioactive waste referred to vitrified HLW canisters, but TRU was added to the category in a June 2007 amendment.
At the end of March 2010 a total of 23,000 vitrified HLW canisters for disposal were said to have accumulated. Actually, most of this was still in the form of spent fuel, while some was in the form of liquid waste. There were only limited quantities of waste in the form of vitrified HLW canisters: 247 canisters at JAEA's Tokai Reprocessing Facility (Tokai Village, Ibaraki Prefecture), 107 canisters at JNFL's Rokkasho Reprocessing Plant, 1,310 canisters returned from France and held at JNFL's Vitrified Waste Storage Center in Rokkasho, and 28 canisters returned from the UK and likewise held at JNFL's Vitrified Waste Storage Center in Rokkasho. A further 820 canisters will be returned from the UK. In addition to these, 70 vitrified HLW canisters that have been substituted for TRU will be returned from the UK. These have been substituted on the basis of the same "integrated toxic potential".
The quantity of HLW to be disposed of in the first period is estimated at 40,000 canisters. It is estimated that in the same period about 18,000m3 of TRU will be disposed of. Most of this will be generated in future at the reprocessing plant and MOX fuel fabrication facility.
Based on the above Act, the Nuclear Waste Management Organization of Japan (NUMO) was established in October 2000 to implement disposal of HLW. It is planned that disposal will begin around 2035. The costs will be covered by electric power companies (in other words by consumers of electricity).
NUMO began seeking candidate sites in December 2002. Due to the amendment adding TRU as a target for geological disposal, three types of offer are being called for: (1) only HLW, (2) only TRU, (3) both HLW and TRU. If there are any candidates, an initial document study will be carried out. These studies will consider such things as whether there is an active earthquake fault, or a volcano nearby. If not, a "summary study" will be carried out. If there are no particular problems after boring has been carried out, the site will proceed to a "detailed study" as a candidate site. During the process of selecting a final site, an underground research facility will be constructed. At each new stage, the views of the governor of the prefecture and the mayor will be sought. It is required that their views be "sufficiently respected".
The process of calling for candidate sites has begun, but although there have been moves to apply for the sake of the subsidies on offer, as soon as such moves came to light there was strong opposition and they were abandoned immediately. In January 2007 the mayor of Toyo Town in Kochi Prefecture submitted an application, but in response there were moves to recall him. He resigned and stood again in the election that followed in April, but a new mayor who opposed the HLW dump was elected and withdrew the application.
Originally the aim was to get five candidate sites for a document study, but there are still no candidates. In an effort to overcome resistance, the government increased the subsidy for a document study from 210,000,000 yen in a single year to 1 trillion yen, with a maximum of 2 trillion yen over two years. In September 2007 the government decided to create an option for it to submit its own applications to local governments and then proceed with document studies if the mayor agreed. Nevertheless, the government still has not submitted any such applications and still no candidates have emerged.
5. Closing Remarks
As the above account shows, it is clear that from HLW to "non-radioactive waste" Japan's radioactive waste policy is totally haphazard. The notion that HLW and TRU can be disposed of together just because in both cases the method is geological disposal is too simplistic. No matter how often it is claimed that they will be kept apart, there is no doubt that collocation will lead to negative interaction between them. It will speed up the rate at which radioactivity will leak out and re-enter the human environment.
In the first place, it is highly doubtful whether geological disposal is safe. In fact, in Japan geological disposal was not originally considered to be an option. In a 1962 interim report the Japan Atomic Energy Commission's (JAEA) expert committee on waste disposal said, "It would be difficult to implement in Japan, with its extremely dense population, limited space, complex ground structure and environmental conditions, including frequent earthquakes."
In an October 1976 policy statement JAEC shifted its stance, saying, "For the time being emphasis will be placed on geological disposal." This was in line with a change of opinion in Europe and the United States, but JAEC also said, "We will rapidly proceed with research into a method of disposal that is in keeping with Japan's social and geographical circumstances." However, since then, although there has been no investigation whatsoever, geological disposal has become the only policy.
Geological disposal involves great dangers for future generations. By using geological disposal the present generation will be unable to take full responsibility. Unfortunately, this generation, which has already produced the legacy of high-level radioactive waste, is unable to avoid placing a burden on future generations.
That is why we must make the burden we leave to future generations as light as possible. We must phase out nuclear energy as quickly as possible. While carrying out serious research into the least dangerous method of disposal, we must simultaneously continue to manage the existing waste in such a way that, in response to technological developments, we can shift to more appropriate locations and more appropriate methods of managing the waste. We must continue to manage the waste, which means that we must find somewhere to manage it. This high-level radioactive waste, which no one wants, must be accepted somewhere and handed on to future generations. Recognizing the sheer scale of this problem is the first step towards solving it.Baku Nishio (CNIC Co-Director)
Return to NIT 138 contents
See CNIC's Radioactive Waste page