Energy Demand and Consumption: There is a prevailing belief that the current model for the world’s energy policy is not sustainable. The major reasons are well known: rising greenhouse gas emissions and their negative impact on the climate, as well as concerns regarding the security of energy supply at affordable prices in the context of increasing needs of energy, notably in developing countries that are enjoying rapid economic growth.
Recommendation 1: No technology should be idolized or demonized. All carbon-dioxide (CO2) emission free energy production technologies should be considered. The potential contribution of nuclear energy to a sustainable energy future should be recognized.
Resources: According to US Geological Survey (2007), Norway is known to have the third to sixth largest thorium resources in the world. These resources, i.e. 170 000 tonnes, have a potential energy content which is about 100 times larger than all the oil extracted by Norway to date as well as the remaining reserves, 4 250 million m3. The information on thorium resources in Norway is, however, based on investigations carried out some 25 to 60 years ago, and no specific thorium exploitation has ever been carried out.
Recommendation 2: Investigation of the resources in the Fen Complex and other sites in Norway should be performed. It is essential to assess whether thorium in Norwegian rocks can be defined as an economical asset for the benefit of future generations. Furthermore, the application of new technologies for the extraction of thorium from the available mineral sources should be studied.
Thorium Fuel: In the 1960s and 70s, the development of thorium fuel for nuclear energy was of great interest worldwide. It was shown that thorium could be used practically in any type of existing reactor. Thorium fuel production and the technical feasibility of the use of thorium in conventional reactors were also demonstrated. Thorium fuel has been tested in the Halden Reactor on several occasions. Due to the worldwide focus on uranium, modern technologies such as automated fuel processing have not been tested on thorium.
Recommendation 3: Testing of thorium fuel in the Halden Reactor should be encouraged, taking benefit of the well recognized nuclear fuel competence in Halden.
Reactor Technology: Today, most of the reactors in operation are of the Generation II type, while new constructions will be based on Generation III and III+, which are significantly improved with respect to safety, security and economics. The next generation reactors, Generation IV, which are currently being developed, are expected to be commercially available in 25 – 30 years. Among the Generation IV reactors, the high temperature reactors, fast breeder reactors and molten salt reactors are most suitable for the use of thorium. Within the GIF (Generation IV International Forum), the use of thorium is only explicitly considered in Molten Salt Reactors.
However, this concept is at present not prioritized.
Recommendation 4: Norway should strengthen its international collaboration by joining the Euratom fission program and the GIF program on Generation IV reactors suitable for the use of thorium.
Accelerator Driven System (ADS) Concept: The ADS concept has been generically developed since 1990, but the construction of a prototype has not yet been launched. An ADS fuelled with
thorium has some clear advantages compared with currently operating reactors; much smaller production of long-lived actinides, minimal probability of a runaway reactor and efficient burning of minor actinides. The lack of experience in operating such a complex system is a major drawback. However, the expected development within the on-going EUROTRANS project should provide information about the feasibility of the ADS concept. It is commonly agreed by OECD countries that energy production with an ADS cannot compete economically with current reactor technology.
Recommendation 5: The development of an ADS using thorium is out of the scope of the Norwegian capability alone. Joining the European effort in that field should be considered.
Norwegian research groups should be encouraged to participate in relevant international projects, although these are for the time being focusing on waste management.
Radioactive Waste from the Front end of the Thorium Fuel Cycle: The dose burden of waste arising from mining and extraction of thorium is significantly smaller than that from uranium, due to the short half-life (T1/2) of Rn-220 (T1/2 = 56 sec) compared with the half-life of Rn-222 (T1/2 = 3.8 days) from U-238 decay chain.
Radioactive Waste from the Back End of the Thorium Fuel Cycle: In contrast to the U-Pu fuel cycle, plutonium and other transuranics are not produced in a pure Th-232/U-233 cycle. The radiotoxic inventory of the waste from the Th-U cycle is significantly lower than that of a U-Pu cycle under the same conditions during the first 1000 years. Already after 100 years, the radiotoxic inventory of the Th-U cycle is significantly lower than that of natural uranium used in an open-cycle for the same amount of energy.
Recommendation 6: Norway should bring its competence with respect to waste management to an international standard, and collaboration with Sweden and Finland could be beneficial.
Radiation Protection of Man and the Environment: Compared to the uranium cycle the radiation protection associated with the thorium cycle is in general of less concern. This is especially so for the back end of the ADS. The competence to assess doses and impact to man and the environment from the thorium cycle in Norway is, however, limited. Already today, the high outdoor gamma doses for instance in the Fen Complex call for restrictions in use of the area.
Doses to man and the environment from future potential exposures associated with the thorium fuel cycle will be regulated by the Radiation Protection Act and associated Regulations. However, authorisation requirements for mining and milling thorium are not included in the current radiation protection regulatory system and revision of the Act will be needed.
Recommendation 7: Norway should bring its competence with respect to dose assessment related to the thorium cycle to an international standard.
Regulation: The Act Concerning Nuclear Energy Activities from 1972 regulates activities associated with the existing Norwegian research reactors. A conventional thorium-uranium based nuclear installation will most probably be covered by the current licensing requirement, whereas a pure thorium-based system such as an Accelerator Driven System (ADS) will not. In such a case, the Act Concerning Nuclear Energy Activities will require revision.
Non-proliferation: The Th-232/U-233 fuel cycles do not produce plutonium. The proliferation resistance to U-233 depends on the reactor and reprocessing technologies. In the development of a reactor technology with its fuel cycle for civil purposes, the thorium fuel cycle should have an advantage concerning the proliferation resistance that can be exploited. However, due to the lack
of experience with industrial-scale thorium fuel cycle facilities we adopt the view that similar safeguard measures as for plutonium are mandatory until otherwise documented.
Recommendation 8: Since the proliferation resistance of uranium-233 (U-233) depends on the reactor and reprocessing technologies, this aspect should be of key concern if any thorium reactor is built in Norway.
Educational and Competence needs: Several studies (e.g. EU, OECD/NEA) have identified the problem that an insufficient number of scientists are being trained to meet the needs of the current and future European nuclear industries. This has been attributed to decreased student interest, decreased course numbers, aging faculty members and aging facilities. Norway has also lost most of its specialists in nuclear sciences after the nuclear moratorium more than 25 years ago. The European education skill base has become fragmented to a point where universities in most countries lack sufficient staff and equipment to provide education in all, but a few, nuclear areas. Of particular concern are special skill-base deficits within technical reactor engineering fields, basic and applied nuclear sciences.
Recommendation 9: Any new nuclear activities in Norway, e.g. thorium fuel cycles, would need strong international pooling of human resources, and in the case of thorium strong long-term commitment of the education and basic science side. All these should be included in the country level strategy aiming to develop new sustainable energy sources. However, to meet the challenge related to the new nuclear era in Europe, Norway should secure its competence within nuclear sciences and nuclear engineering fields. This includes additional permanent staff at the Universities and research institutes and appropriate funding for new research and development as well as high quality research-based Master and PhD education.
Concluding Remarks: The Thorium Report Committee finds that the current knowledge of thorium based energy generation and the geology is not solid enough to provide a final assessment regarding the potential value for Norway of a thorium based system for long term energy production. The Committee recommends that the thorium option be kept open in so far it represents an interesting complement to the uranium option to strengthen the sustainability of nuclear energy.