Worldover there are three main accepted methods of fuel generation through nuclear fuel cycle. The fuel transformation in these three methods occurs as follows;
- Enriched Uranium-232 after fission produces plutonium as the by product.
- Plutonium obtained as by product is converted to Uranium-233 and enriched plutonium. (Fast breeder technology)
- Uranium-233 is to be converted to a reusable form. Research is undergoing the world over for perfecting this technology.
Through the deal we plan to import light water reactors (LWR) and plan to use the spent fuel in this stage to launch fast breeder reactors. The deal also provisions for the import of Uranium as India is running short on Uranium resources (ref. Part 2).
The indigenous research going on in India attempts to use the nuclear fuel in three consecutive stages thereby providing more efficiency and is called the three-stage program. India's three stage program plans to utilize the vast thorium resources that we have (approx. 225,000).
The indigenous research going on in India attempts to use the nuclear fuel in three consecutive stages thereby providing more efficiency and is called the three-stage program. India's three stage program plans to utilize the vast thorium resources that we have (approx. 225,000).
According to DAE chairman Anil Kakodkar, the highest breeding ratio in FBRs is achieved with Plutonium-Uranium based metallic fuel is used in the core and Uranium as a blanket. The strategy advocated by the DAE scientists is that of introducing a thorium blanket in the Pu-U fuelled FBR. But Kakodkar says that this has an adverse impact on the doubling time, which will have an adverse effect on the growth of the installed FBR capacity in the initial part of the second stage.
An essence of Kakodkar's proposal is as follows, Since the slow growth based on Pu-U breeders using Plutonium derived from the small indigenous PHWR base of 10GWe would leave an unmet demand of 412Gwe by 2050, the plutonium obtained by reprocessing the spent fuel of the imported 40 GWe LWRs should be used to launch another series of metallic Pu-U breeders whose exponential growth, starting as it does from a larger LWR capacity base, will be able to meet this energy deficit by 2050.
But when is the indigenous breeder technology using metallic fuels expected to mature? Kakodkar says it will be after 3 decades after the introduction of metallic fuel FBRs by 2022. Therefore thorium based technology will have to wait till 2050. It is thus planned so that by 2050, the supply demand curves would have intersected and then we will have ample time to go for thorium based technology as the demand-supply curves will be drifting away much slower once the gap has been closed.
Or in the extreme circumstances we may be self sufficient as much as to abandon the indigenous program.
A differing voice can be heard from Placid Rodriguez, former director of Kalpakkam Indira Gandhi Centre for Atomic Research and a key player in India's development of breeder program. He advocates an early introduction of thorium cycle. The scenario envisaged by Rodriguez is that of deploying both second stage fuel cycle and third stage fuel cycle involving thorium in parallel. This will give a combination of Pu-U breeders (that breed only Pu-239) with Pu-U breeders having a thorium radial blanket in the second part of the second stage (that breed both Pu-239 and U-239) and of U-233 thorium breeders (That will breed U-233) with heavy water if other thermal reactors that use thorium (like AHWRs) towards a self sustaining U-Th cycle in the third stage. This ensures both good growth potential as well as energy security without being tied to imported fuel for lifetime of reactors.
The strategy advocated by Rodriguez, is based on studies conducted by SM Lee of IGCAR. He had looked at four (fissile/fertile) fuel combinations: Pu-239/U-238, Pu-239/Th-232, U-233/Th-232 and U-233/U-238 in the core and using either U-238 or Th-232 as blanket in each of these combinations. Lee showed that on the basis of the 10 GWe PWHR base, launching thorium based FBRs with advanced metallic fuels in parallel with thorium-less U-Pu breeders or with a little lag would achieve the requisite energy growth.
The statements by Kakodkar, who is identified in public mind with India's thorium utilization, that thorium which has all along been hailed as the panacea for our energy security and independence is suddenly found to have nuclear properties that do not allow fast growth in power generation capacity seems like an alibi for Indo-US nuclear deal.
The strategy advocated by Rodriguez, is based on studies conducted by SM Lee of IGCAR. He had looked at four (fissile/fertile) fuel combinations: Pu-239/U-238, Pu-239/Th-232, U-233/Th-232 and U-233/U-238 in the core and using either U-238 or Th-232 as blanket in each of these combinations. Lee showed that on the basis of the 10 GWe PWHR base, launching thorium based FBRs with advanced metallic fuels in parallel with thorium-less U-Pu breeders or with a little lag would achieve the requisite energy growth.
The statements by Kakodkar, who is identified in public mind with India's thorium utilization, that thorium which has all along been hailed as the panacea for our energy security and independence is suddenly found to have nuclear properties that do not allow fast growth in power generation capacity seems like an alibi for Indo-US nuclear deal.
