Chairman of India’s Atomic Energy Commission Anil Kakodkar has announced recently in Vienna a special version of the forthcoming Advanced Heavy Water Reactor (AHWR) adapted to use low-enriched uranium (LEU) fuel.
The original design is fuelled by a mix of uranium-233 and plutonium bred from thorium using fast neutron power reactors earlier in a thorium fuel cycle. The LEU variant is suitable for export because it does away with the plutonium, replacing it with uranium enriched to 19.75 percent uranium-235.
Producing 300 MWe, the unit is less than one third the capacity of a typical large reactor. It is designed to operate for up to 100 years and has a “next generation” level of safety that grants operators three days’ grace in the event of a serious incident and requires no emergency planning beyond the site boundary under any circumstances.
The design is intended for overseas sales, and the AEC says that “the reactor is manageable with modest industrial infrastructure within the reach of developing countries.”
The new fuel mix, AEC said, produces less plutonium than mainstream light-water reactors and what it does produce contains three times the proportion of plutonium-238, lending it proliferation resistance. Furthermore, it leaves only half the amount of long-lived radioactive waste per unit of energy compared to mainstream light-water reactors.
As well as introducing India as a potential new major player in reactor sales – especially to new markets – the announcement reaffirms India’s commitment to proceeding with the thorium fuel cycle using the original AHWR as the final stage.
India was effectively isolated from international nuclear trade from 1992 until early this year when a US-led initiative resulted in special arrangements for India under the Nuclear Supliers Group, based on an India-specific safeguards agreement with the International Atomic Energy Agency. Overseas firms can now do business with India, which is keen to import uranium and large power reactors. In turn, India may now offer its goods and services to the wider world.
The long-term goal of India’s nuclear program has been to develop an advanced heavy-water thorium cycle. The first stage of this employs the pressurized heavy-water reactors and light water reactors, to produce plutonium.
Stage two uses fast neutron reactors to burn the plutonium and breed uranium-233 from locally mined thorium. The blanket around the core will have uranium as well as thorium, so that further plutonium is produced as well.
In stage three, AHWRs burn the uranium-233 from stage two with plutonium and thorium, getting about two thirds of their power from the thorium.
The first AHWR is meant to start construction in 2012, although no site has yet been announced. A prototype 500 MWe fast neutron reactor being built at Kalpakkam should be complete in 2011.