india thorium based fast breeder reactors

Fast breeder nuclear reactors

India developing thorium based fast breeder nuclear reactors

A team of scientists  at a premier Indian nuclear facility has made theoretically design of innovative reactor that can run on thorium-available in abundance in country- and will eventually do away with  the need for uranium.

But the project largely depend upon the U.S. playing the ball. The novel fast thorium breeder reactors (FTBR) being developed by V. Nathaniel   and his team at Bhabha Atomic Research Cent re( BARC) in Mumbai has received global attention after paper was submitted to the International Conference on Energy Nuclear Energy Systems (ICENES) at Istanbul.

Power reactors of today mostly use fissile fuel called uranium (U- 235), whose fission releases energy and “ ‘spare neutrons that maintain the chain reaction. But only seven  out of 1000 atoms naturally uranium are  of this type. The rest are “ fertile “  meaning they cannot fission but can be converted into fissionable Plutonium  by neutrons released by U-235.

Thorium is three times more abundant in earth’s crust than uranium but was never inducted into reactors because-unlike uranium-it has no fissionable atoms to start the chain reaction.

But once the world’s uranium run out, thorium and depleted uranium discharged by today’s power reactors-could form “fertile base “ for nuclear power generation, BARC scientists claim in this paper.

They believe this FTBR is one such candidate reactor that can produce energy from these two fertile materials with some help from fissionable Plutonium as “Seed “ to start fire.

By using judicious mix of “seed “ plutonium and fertile zones inside core ,the scientists show theoretically that their design can breed not one but two nuclear fuels-U-233 from thorium and plutonium from depleted  uranium-within the same reactor.

This totally novel concept of fertile-to fissionable conversion has prompted its design to christen their baby the fast “Twin ’ breeder reactor.

This calculations show the sodium cooled FTBR , while consuming 10.96 tonnes  of plutonium   to generate 1000 MW of power, breeds 11.44 tonnes plutonium  and 0.88 tonnes of U-233 in a cycle length of two years. At present there are no internal fertile blankets or fissionable breeding zones in power reactors operating in the world, the paper claims.

The concept has won praise from nuclear scientists elsewhere. “ core heterogeneously  in best way to help high conversion “ says Alexis Nulter  a French nuclear scientist at LPSC reactor physics group in Grenoble thorium based fuels and fuel cycle have been used in the past and are being developed  in a few countries but yet  to be commercialized .

France is also studying a concept of “molten salt reactor” where the fuel is in liquid form, while U.S. 
Considering a gas cooled reactor using thorium. McLean Virginia -based thorium power limited  of U.S. has been working nuclear engineers and scientists of Kurchator institute of Moscow for over decade to develop designs that can be commercialized

But BARC’s  FTBR is claimed to be first design that truly exploit’s the concept ‘breeding “ in a reactor that uses thorium. The hand fuel of fast breeder reactor (FBRs) in the world today including one in India building at Kalpak am near Chennai -use plutonium as a fuel.

These breeders have to wait until enough plutonium is accumulated through reprocessing of spent fuel discharged by thermal power reactors that run on uranium.

Herein  lies the rub

India does not have sufficient uranium  to build thermal reactors to produce  plutonium needed for more FBRs of Kalpak am type. The India -U.S.civil nuclear deal  will enable India  to import uranium fuel and reprocess spent fuel to recover plutonium for FBRs.

Jaganathann design is one way of utilizing thorium and circumventing the delay  in building plutonium -based FBRs says former BARC director P.K. Iyyengar .

Meanwhile India’ s 300,000  tonnes of thorium reserves-the largest in world-the beach sand of Kerala and Orissa states are waiting to be tapped. The BARC scientists say that thorium should  be inducted into power reactors when uranium is still available, rather  than using after it is exhausted.

But FTBR still needs an initial inventory of plutonium to kick start the thorium cycle and eventually to generate electricity.

“he US and Russia  have piles of plutonium from dismantled nuclear weapons” Iyyengar told adding                                  ‘” they should allow as to borrow this plutonium need to start our breeders. We can return material after  we breed enough.

India first fast breeders

India’s first 40 Mwt fast breeder test reactor (FBTR) attained  criticality on 18th October 1985.

India becomes the six nation having technology to build and operate FBTR beside U.S., U.K. France, Japan and USSR.

The unique features of Indian FBTR are
1. Indigenous developed U-PU carbide fuel rich in PU.
2. Design development and fabrication of all machinery, peripheral units and materials are by Indian scientists in close co-ordination with industry.

Status : Initial operational problems sorted out and reactor operates smoothly at a steady power level of 10.5MWt maximum possible power out put owing to small core.

Future plans  : Based on design setting up and operation FBTR has provided rich experience and immense information with liquid metal cooled  fast breeder reactor technology and also confidence to embark upon the design of 500 Mwe  pro to type fast breeder reactor (PFBR) at Kalpakkam .

At forefront of nuclear power research is 500 MW prototype fast breeder reactor (PFBR)being constructed at Indira  Gandhi Center for Atomic Research (IGCAR) Kalpakkam at Tamilnadu. An FBR requires high speed neutrons to produce fissionable material that can produce energy. For the development of atomic energy, India’s  reactors are based on heavy water but they use natural uranium as a fuel and India has limited uranium resources and cannot import uranium because global sanctions. So capacity expansion for heavy water restricted to 10,000 Mwe. Explains S.Balder Raj  director IGCAR “ FBRs beside fission of uranium 235, there is gain fuel conversion of 99.3 per cent uranium 238 to plutonium 239 which turn fissionable. The effective  utilization of uranium resources goes up in FBRs and India achieve respectable capacity by 2020.

But FBRs generate too much heat. To remove it liquid sodium is used, unlike conventional reactors that use water. Since sodium burns on contact with air or water  FBRs are susceptible to fires and shut downs. For instance the French Super phoenix reactor operated for less than one year in its first 10 years. But Raj confidently says that “ there is 300 years of experience in FBRs globally and India has 30 years  experience  . There is nothing to hint that technology is not doable “ if all also well the PFBR-a cost of 3492 crores will generate electricity in 2011 and supply power RS 3.20 per unit. By 2020 four  FBRS of 500 Mwe each are envisaged.

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