THORIUM AS AN ENERGY SOURCE - Opportunities for Norway ...

Conclusions and Recommendations
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
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