Japan has carried out nuclear power generation research since the middle of the 1950s. A test power reactor, the Japan Power Demonstration Reactor (JPDR), started operation in 1963 and Tokai-1 Nuclear Power Plant (NPP), the first commercial reactor, went into operation in 1966 with a generation capacity of 166 MWe. Currently, about 50 commercial nuclear reactors, predominantly boiling water reactors (BWRs), and pressurised water reactors (PWRs), are in operation, with a total generation capacity of 48,847 MWe. Prior to the Fukushima disaster, about 30% of Japan ’s electricity came from nuclear power (Plate VIII between pages 448 and 449). Japan will continue to develop nuclear power as a mainstay of non-fossil energy, while placing the highest priority on safety1.

The Framework for Nuclear Energy Policy (FNEP), which was estab­lished by the Japan Atomic Energy Commission (JAEC) as the basics for political measures regarding the use of nuclear power generation and radia­tion to be promoted by governmental agencies for the next 10 years, was approved by the Cabinet in October 20052.

Prior to the events at Fukushima, nuclear energy was expected to con­tinue to contribute to the pursuit of an optimum energy supply mix for Japan. The FNEP specified that nuclear power’s share of Japan’s total power generation should be maintained at 30-40% or more beyond 2030 and that the nuclear fuel cycle should be promoted3. Nuclear power genera­tion is the key base-load power source. After Fukushima, in July 2011, the Energy & Environment Council (Enecan or EEC) was set up by the Cabinet Office to recommend on Japan’s energy future to 2050. It is chaired by the Minister for National Policy and will focus on future dependence on nuclear power. In September 2011, Japan ’ s prime minister said he expected the country to reduce its dependency on nuclear power in the medium and long term, and that the government would address the question of those new plants now under construction. He said that the national Basic Energy Policy would be revised from scratch, and that a new strategy and plan to 2030 would be created. He also stated that Japan’s ministerial-level Energy and Environment Council would ‘thoroughly review nuclear policy and seek a new form’. The review may recommend that nuclear power’s contri­bution to electricity be targeted at 0%, 15%, or 20-25% for the medium term — a 36% option was dropped.

H. RIN D O, K. TAKAHASHI and M. TACHIB ANA, Nuclear Cycle Backend Directorate, Japan

DOI: 10.1533/9780857097446.2.723

Abstract: This chapter summarizes the current strategy and policy for radioactive waste management in Japan which has been hindered by a lack of public acceptance and of a final high level waste end-point (geological repository). Ongoing decommissioning of several nuclear facilities, including the Tokai-1 NPP, the Advanced Thermal Reactor ‘Fugen’ and the Plutonium Fuel Fabrication Facility (PFFF), are described.

Key words: radioactive waste treatment, radioactive waste disposal, decommissioning and dismantling, nuclear facilities, policy and strategy, Japan.

22.2 Introduction

This chapter was written largely before the Fukushima accident, details of which and the clean-up programme are included in the next chapter. However, not only nuclear policy but also nuclear safety regulation in Japan is likely to change in the future.

The Law of the People’s Republic of China on Environmental Impact Assessment states that for projects that may have adverse environmental impact, public meetings should be held or other approaches adopted to solicit comments on the draft environmental impact assessment statement from relevant organizations, experts and the public before its submission for review and approval. The constructor and the operator of the proposed site will need to take into consideration the comments provided from the relevant organizations, experts and the public, and provide additional explanations on whether these comments have been incorporated when submitting the environmental impact assessment report for review.

Beishan is regarded as the most likely area for China’s GDF, because there is/are:

• no economic prospects for the Gobi desert area, future possibilities may be in wind energy and solar energy but they will be located at the surface;

• very low population density and the prediction is that it will remain the same in the foreseeable future since there are no important mineral resources;

• extremely low rain fall (60-80 mm/year) and very high evaporation rate (2900-3200 mm/year),

• convenient transportation, as it is on the edge of the Gobi desert and about 200 km from the main east-west train lines and motorways.

• favourable geology with stable granite and diorite rocks and suitable hydrogeological conditions;

• international programmes in similar granite host rock using the multi­barrier concept [16-18].

Progress at Beishan includes site selection of an area covering hundreds of square miles with a crust thickness of 47-50 km and no earthquakes with magnitudes over 4.75 on the Richter scale ever having taken place. The topography of the area is flat with some small hills with elevations above sea level ranging from 100-2,000 m. Original site characterization, in particular its hydrogeological properties, showed very poor groundwater resources. Average precipitation is 70 mm/year while evaporation is about 3,000 mm/year and there is no year-long stream and other surface water body in the area. Geo-stress and borehole measurements also gave positive results with tensile strength from 5 to 7 MPa and compression strength from 5 to 13 MPa, reflecting samples obtained from a depth of 200-500 m, while maximum lateral stress reached is 25 MPa at a depth of 500 m.

After more than 20 years of geological survey and investigation, the Beishan area was chosen as one of China ’s likely areas for its GDF for HLW/SF. Beishan, in the Gobi desert, is extremely dry and has been unchanged for millions of years. It is located in a remote area of Gansu Province in northwest China, not far from the west end of China’s Great Wall, Jia-Yu Guan (Jia-Yu Fortress). The narrow aubergine-like Gansu province is also referred to as Western River Corridor (Yellow River West Corridor), linking central China to China’s Xinjiang Autonomous Region — crossing and along the Gobi Desert through about a thousand miles linking to the west part of Asia and Eastern Europe as shown in Plate VII (between pages 448 and 449).

A thorough geological survey has been carried out at Beishan (Fig. 22.7). In August 2005, the CAEA revised the long-term HLW geological reposi­tory programme, with the objective of building China’s HLW geological repository by about 2050. China is closely monitoring the potential envi­ronmental impacts of nuclear energy for future generations, particularly where HLW/SF and geological disposal are concerned. China ’s regulator body, the SEPA, implements the activities related to radioactive waste and disposal, which have been managed by the China National Nuclear Corpo­ration (CNNC). Furthermore, China ’s HLW/SF geological disposal R&D programmes are carried out by CNNC’s research and engineering organiza­tion and led by BRIUG.

The Chinese government has approved a three-phase GDF programme:

1. Phase I: Site selection and site confirmation (2001-2020): Technical preparation, HLW disposal/repository programme started in China; geo­logical study, preliminary site characterization and evaluation: investiga­tions on surface geology, hydrogeology and geophysics with the drilling of four boreholes (BS01-04) and in-situ tests in boreholes.

2. Phase II: Underground Research Laboratory (URL) construction and in-situ tests (2010-2030): in-situ tests on EBS on backfill/buffer materi­als, radionuclide migration and use of the necessary natural analogues; mock-up tests and underground lab tests of backfill/buffer materials, together with coupled THMC tests.

3. Phase III: Repository construction (2030-2040): Construction structural design, simulation and modelling, construction and preparation of geo­logical repository engineering work.

While the granite site at Beishan is regarded as the most likely site, China is keeping its options open by also examining a potential GDF site in clay formations in Xinjiang in northwest China.

Public concerns over the global ability to manage, and eventually dispose of RAW, especially HLW/SF, remain high. Emplacement in the deep geology is an internationally recognized disposal solution for HLW and SF, and China is planning to use this route. While China’s GDF programme is at an early stage, like all international waste management programmes imple­menting geological disposal, it is considering multi-barrier concepts com­prising engineered and natural barriers between the HLW/SF in the geosphere and the biosphere, while bentonite-based engineered barrier systems (EBS) were considered in China as early as the 1990s [16-17]. The current preliminary geological disposal concept for its HLW/SF is to use a shaft-tunnel model in the saturated zones of granite rock (Fig. 22.4). Over the past 20 years, China has made great strides in its geological repository programme including, as described above, geologically surveying the whole country for its georepository site selection and optimization of backfill/ buffer materials that will be needed for the GDF safety cases [18].

Many other countries are developing similar concepts for permanent disposal of radioactive waste deep underground: solidification of HLW/SF

Bentonite

backfill

A multi-barrier concept

Buffer

22.4 China s preliminary HLW repository concept.

using glass and ceramics, packaging in metal canisters, following temporary storage above ground before permanent geological disposal in natural barrier systems such as a granite rock-body, using a multi-barrier system [16,17]. Chinese researchers have suggested that EBS is a major component in guaranteeing long-term safety, making it necessary to conduct fundamen­tal research on the coupled THMC (thermal-hydrological-mechanical — chemical) behaviour of bentonite under simulated geological disposal conditions, and subsequently to reveal the property changes of the ben­tonite over a long period of time.

The requirements for HLW backfill materials are long-term chemical and physical stability, good mechanical properties, volume expandability in contact with water and very low water penetrability. Other requirements also include the ability to hinder nuclide migration, good thermal conduc­tivity and thermal stability, radiation resistance and stability, natural avail­ability and importantly, low cost.

Many years of research in Europe and China on bentonite backfill mate­rials for the EBS has revealed that bentonite comprising predominantly montmorillonite is considered to give the best performance in terms of low water penetration, high volume expansion, and excellent nuclide absorption and retention, as well as being abundant.

China is rich in mineral reserves and has large bentonite reserves suitable for the EBS backfill/buffer (at one site with a volume of 40 x 40 x 0.7 km) in China’s Inner Mongolia region near Beijing. Bentonite with high content of expandable montmorillonite has been found in an area named Gao — Miao-Zi (GMZ, which in English means Highland Temple). This single reserve, as shown in Fig. 22.5 is over 280 x 106 tonnes.

It is expected that the bentonite at Gao-Miao-Zi will be used in China’s HLW/SF geological repositories. This bentonite is being considered as a part of the EBS due to its ability to retain radionuclides and other hazardous materials. Prior to considering modular designs for canister encapsulation in the GDF, bentonite natural resources, raw mineral analysis, characteriza­tion and processing, need to be investigated, developed and optimized for large-scale cost-effective manufacture. To demonstrate the long-term safety of a GDF in China, the influence of the bentonite composition and the properties of the compacted block/brick must be studied.

Some large-scale mock-up facilities have also been built in China to test the efficacy of backfill/buffer materials such as bentonite with designed canisters. A China mock-up test was recently initiated after a long period of research conducted with international support. It is based on a prelimi­nary concept of the HLW granite rock environment repository in China [19] . It was developed to investigate the THMC properties of compacted GMZ-Na-bentonite as shown in Fig. 22.6 . which reveals the arrangement of compacted bentonite mineral blocks inside the mock-up test steel. The work has been carried out and led by the Beijing Research Institute of Uranium Geology (BRIUG) [20-22] . The device contains a heater, which

simulates the heat from a container of HLW/SF, placed inside the com­pacted GMZ Na-bentonite blocks with total dry density 1,600 kg/m3. Water inflow through the barrier from its outer surface simulates the water pen­etration. The device is a large steel tank of 900 mm internal diameter and 2200 mm in height. The experiment is being performed at the BRIUG labo­ratory and the design concept is shown in Fig. 22.6 and Plate VI (between pages 448 and 449). In Fig. 22.6, the compacted engineered bentonite blocks are arranged inside a mock-up test facility within a steel tank (top view). This mock-up THMC test consists of a heater (canister), bentonite blocks within a cylindrical steel tank, as shown in Plate VI as a sketch of the cross section of the China mock-up facility and the arrangement of central heater, steel canister, bentonite blocks/bricks and multiple sensor arrange­ment [22] .

Under the Law of the People’s Republic of China on Prevention and Control of Radioactive Pollution [9], the competent nuclear facility author­ity under the State Council (National Atomic Energy Agency), in conjunc­tion with environmental competent authority under the State Council, has been developing a programme for the siting of a HLW geological disposal facility (GDF). The siting programme is based on the geological conditions, the solid RAW disposal needs, and the associated need for an environmen­tal impact assessment. This programme cannot be implemented without the approval of the State Council. Based on such a programme, the relevant local governments would provide construction land for the solid RAW repository and take effective steps to support the disposal of such waste. Disposal of solid RAW on any inland river and or marine environment is prohibited. The Law of the People’s Republic of China on Prevention and Control of Radioactive Pollution defines that HLW shall be disposed of in a centralized deep geological repository.

The ‘Guidance on Siting of Radioactive Waste Geological Repository’ states that the basic aim is to select a site suitable for disposal of HLW, where the disposal facility and waste package would be able to effectively isolate radionuclides from entering into the biosphere over geological timescales. The site could provide one or more natural barriers to keep the adverse impacts on the population and the environment at the acceptable level specified by the national regulatory body. Studies of deep geological disposal of HLW in China began in 1985, when the initial R&D programme was initiated under the auspices of the former MNI in respect of engineer­ing, geological, chemical and safety issues. Experimental facilities were established to simulate the chemical environment of potential geological disposal environments. At the same time, a preliminary safety assessment of geological disposal was launched. A study on the pre-siting of HLW disposal facility was also conducted. Preliminary regional comparisons have been performed for five regions: East China, South China, Southeast China, Inner Mongolia and Northwest China. However, the characterization work has focused on Northwest China.

In 2006, the Guides on Research and Development Planning of Geologi­cal Disposal of HLW were issued jointly by China Atomic Energy Admin­istration (CAEA), Ministry of Science and Technology (MOST), and China’s regulator the State Environmental Protection Administration (SEPA). The overall purpose of the study on geological disposal of HLW in China is to select the potential site with stable geological and suitable socio-economic environment and then to complete the construction of the country’s geological disposal facility for solid HLW in a manner that pro­tects the environment and the public from unacceptable hazards through the containment and retardation effects of engineered and geological barriers.

Under these guidelines, geological disposal of HLW R&D is divided into three stages:

1. laboratory R&D and siting of the disposal facility (2006-2020),

2. underground experimentation (2021-2040), and

3. demonstration of a prototype disposal facility and demonstration and construction of such disposal facility (2041-mid-21st century).

Around 2020, the following tasks are expected to be completed:

• the in-laboratory R&D project involving multidisciplinary fields,

• preliminary siting of a disposal facility,

• a feasibility study for an underground laboratory, and a safety review for construction of an underground laboratory.

Around 2040, the following tasks will be completed:

• R&D for the underground laboratory,

• preliminary confirmation of the disposal facility site,

• pre-feasibility study report of disposal facility, and

• feasibility study and safety review of prototype disposal facility.

From 2040 to the mid-twenty-first century, the following objectives would be achieved:

1. demonstration experiments of the prototype disposal facility,

2. final confirmation of disposal facility site,

3. feasibility study of the disposal facility and safety assessment for the disposal facility construction,

4. disposal facility construction, and

5. the safety review for disposal facility operation.

Requirements on surveillance control of disposal facilities after closure have been laid down in China. The Regulations on Radioactive Waste Safety (HAF401) require that, after closure of a disposal site, institutional surveillance and control should be maintained to:

• prevent inadvertent public intrusion onto the site,

• prevent movement and disturbance of disposed radioactive materials,

• monitor the performance of the disposal site against design basis stand­ards, and

• implement necessary remedial actions.

The period following closure of a disposal facility generally includes closed, semi-closed and open phases. Closed phase means a period when the dis­posal facility that has just been closed is kept under closed condition and that no one can access it unless for the purposes of a supervisory task. Semi-closed phase means a period when waste is covered with well — structured cover and associated hazards has proven very small, and people are allowed access but without any activities relevant to drilling and excava­tions. Open phase means a period when radioactivity of waste has reduced to the level at which radiation protection is no longer needed following expiration of the required control period and the site can be fully open to the outside.

Post-closure surveillance of the localities where a disposal facility is located are the duty of the local government. Costs required for carrying out post-closure maintenance, monitoring and emergency measures are estimated before the operation of such a disposal facility and collected in an appropriate amount from the associated waste disposal fees. Re-estimation, and necessary adjustment, can be made for such costs to meet the changing circumstances. Post-closure supervision, such as environmental monitoring, access restriction, installation maintenance, file preservation and possible emergency actions, should be carried out under the auspices of the envi­ronmental protection agencies at both the national and the provincial levels. Both the Guangdong Beilong and the Northwest China LILW disposal sites are in operation, and far from closure.

In the 1980s, radioactive waste disposal work was initiated in China. The former Ministry of Nuclear Industry (MNI) subsidiary Science and Technol­ogy Committee set up a panel to examine RAW treatment and disposal. The siting of solid LILW disposal facilities began in the 1980s and was implemented under the auspices of the former MNI. The initial siting work was conducted in South China, East China, Northwest China, and Southeast China based on the distribution of nuclear facilities at that time. Determina­tion of the South China disposal site began in 1991, with 27 candidate areas being selected. Of these, 20 were investigated on site and three candidate sites were identified. In 1998, initial reconnaissance was carried out within the area of Zhejiang province, East China, with 17 areas surveyed and five candidate sites identified. In Northwest China, two candidate sites were identified on the basis of six surveyed areas. After further comparison, a disposal site in the northwest was determined. In southwest China, exami­nation of disposal sites was carried out from 1989 to 1991. The site survey was carried out in ten candidate areas selected from an initial 38 areas, of which three candidate sites were finally recommended.

China’s Environmental Policy on Disposal of LILWs was issued in 1992 (hereinafter referred to as Paper 45) [15], which clarify the environmental policy on LILW. Paper 45 states that national disposal facilities for LILWs shall be constructed in the regions where major waste generation occurs in order to dispose of LILWs generated in the region and neighbouring regions. Paper 45 played an active role in promoting the siting and construction of LILW disposal sites. In 1998, construction of the Northwest disposal facility was completed, with planned capacity of 200,000 m3. The first phase of construction was planned to generate 60,000 m3 of disposal capacity, and so far 20,000 m3 has been constructed. The Northwest disposal facility is currently in trial operation. By the end of 2006, this site received 471 m3 of LILW with total activity of 3.05 x 1012Bq. In August 2000, Guangdong Beilong, China’s second solid LILW disposal facility was constructed in the Guangdong Province with planned long-term capacity of 240,000 and planned near-term capacity of 80,000 m3 . The total capacity that has been constructed in the first phase was about 8,800 m3 and, by the end of 2006, the received waste amounted to 1403.2 m3. Environmental monitoring indi­cates that operation of these two LILW disposal sites has no negative impact on the surrounding environmental radiological levels and no radia­tion accident has occurred to date.

Under the Law of the People ’s Republic of China on Prevention and Control of Radioactive Pollution of 2003 [9], the relevant government agen­cies are developing the national programme of finding solid radioactive waste disposal sites. The principle is to make an overall plan and implement the project in a step-wise, convenient and economical way to ensure safety. Based on the future development of NPPs and the distribution of waste generation varying with time and region, the overall development pro­gramme for LILW disposal will be established including allocation of regions, siting planning, capacity of disposal site and construction plan. Based on the programme, a phased implementation approach shall be developed to keep the number and capacity of disposal sites countrywide adequate to meet the demand for RAW disposal in the various regions. Construction of disposal facilities on the sites that have been chosen should be implemented in phases based on the quantity of LILWs generated and on a basis of gradual disposal capacity extension so as to achieve the effec­tive disposal capacity. When considering the safety of LILW disposal, trans­portation is one of the most important factors. Full account must be taken of the safety, economics, and convenience of RAW transport. To this end, a reasonable arrangement should be made for the coverage of each regional disposal site.

To keep pace with the development of nuclear technology applications, temporary storage facilities have been constructed in China since the 1960s. The Notification on Strengthening Radioactive Environment Management

Arrangement was issued in the Temporary Regulations on Construction of Urban Radioactive Waste Repository in 1984. The Methods on Urban Radio­active Waste Management was issued in 1987 [12,13]. Temporary waste storage facilities are constructed on a provincial basis. Each province (or autonomous region, or municipality directly under central government) builds one such facility to accommodate wastes arising from research, teaching, medicine and other applications of radioisotope and nuclear tech­nology within the province. Provincial environmental protection agencies have set up special organizations staffed with specialists responsible for supervision and environmental monitoring. The Criteria on Siting, Design and Construction of Application Waste Storage Facility was issued in 2004 [14] and requires the modification and extension to be carried out for exist­ing storage facilities to meet the new requirements. At present, special funds have been appropriated for this purpose. It also requires an environmental impact assessment to be made prior to such modification and extension, which cannot be implemented without approval by the relevant agencies. By the end of 2010, a total of 31 waste storage facilities, together with one centralized storage facility for spent radioactive sources, had been con­structed and/or upgraded in compliance with the new requirements. At the end of 2006, these facilities had received 64,572 m3 of disused sealed sources, of which 49,741 m3 are in the provincial storage facilities, and the remainder is in the national centralized facility.