ABSTRACT

The Chinese government has decided that the installed capacity of nuclear power plants (NPP) will reach 40 GW by the year of 2020, while other 18 GW under construction, and the electricity produced by NPPs will make up 4% of the whole installed capacity. In such case, the spent fuel generated from those NPPs will reach 82,630 tons by 2050, while the estimated cost will be 130 billion Chinese RMB. The Chinese policy is that, the spent fuel from light water reactors will be reprocessed first, followed by verification and final disposal. The preliminary repository concept is a shaft-tunnel model, located in saturated zones in granite, while the final form for disposal is vitrified high level radioactive waste (HLW). In 2006, the China Atomic Energy Authority (CAEA), the government department in charge of HLW disposal, published a long term R&D plan for geological disposal of high-level radioactive waste. The program is divided into 3 stages:

  1. Laboratory Studies and Site Selection for HLW Repository (2006–2020);

  2. Underground in situ tests (2021–2040);

  3. repository construction (2041–2050).

One of the major milestones is to complete the construction of an underground research facility by 2020. In the program, the 5 major R&D areas include: studies on strategies, regulations and standards; site selection and site characterization; engineering design for underground facilities and repository; safety assessment study; and radionuclide migration study. With the support of CAEA, comprehensive studies are underway. The site characterization is performed in the most potential Beishan site in northwestern China's Gansu province. Engineered barrier studies are concentrated on the Gaomiaozi bentonite and corrosion of carbon steel material. A mock-up facility, which is used to study the thermal-hydraulic-mechanical-chemical properties of bentonite, is under design. Several projects on rock mechanical properties of Beishan granite are also underway. The concept design for China's HLW repository is under discussion. However, the Chinese HLW disposal program is still facing social, scientific, technical, engineering challenges. The key scientific challenges include:

  1. precise prediction of the evolution of the repository site;

  2. characteristics of deep geological environment;

  3. behaviour of deep rock mass, groundwater and engineering material under coupled conditions;

  4. geochemical behaviour of transuranic radionuclides with low concentration and its migration with groundwater; and

  5. safety assessment of disposal system.

1 INTRODUCTION

In 2007, the top Chinese government organization, the State Council, approved the "Medium- to Long Term Plan for the Development of Nuclear Power Plants in China (2006–2020)" (SCC, 2007), indicating that the installed capacity of nuclear power plants (NPP) should reach 40 GW by 2020, while another 18 GW NPPs are under construction then. According to the plan, the electricity produced by NPP will make up 4% of the whole installed capacity. This means that about 30 more nuclear reactors (1 000 MW-grade) will be constructed before the year of 2020. As a consequence, the total spent fuel generated from those NPPs during their life time will reach about 83,000 tHM.

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