The status of India nuclear programme (GS Paper 3, Science and Technology)
Why in news?
- Recently, Prime Minister Narendra Modi witnessed the start of the process of core-loading the indigenous Prototype Fast Breeder Reactor (PFBR) at the Madras Atomic Power Station in Kalpakkam, Tamil Nadu.
What is the PFBR?
- The PFBR is a machine that produces more nuclear fuel than it consumes. Its core-loading event is being hailed as a “milestone” because operationalisation of the PFBR will mark the start of stage II of India’s three-stage nuclear power programme.
- In the first, India used Pressurised Heavy Water Reactors (PHWRs) and natural uranium-238 (U-238), which contains minuscule amounts of U-235, as the fissile material.
- In nuclear fission, the nucleus of an atom absorbs a neutron, destabilises, and breaks into two while releasing some energy. If the destabilised nucleus releases more neutrons, the reactor’s facilities will attempt to use them to instigate more fission reactions.
- The heavy water in PHWR slows neutrons released by one fission reaction enough to be captured by other U-238 and U-235 nuclei and cause new fission. The heavy water is pressurised to keep it from boiling. The reactions produce plutonium-239 (Pu-239) and energy.
Three stages:
- Only U-235, not U-238, can sustain a chain reaction but it is consumed fully in stage I.
- In stage II, India will use Pu-239 together with U-238 in the PFBR to produce energy, U-233, and more Pu-239.
- The Department of Atomic Energy (DAE) set up a special-purpose vehicle in 2003 called Bharatiya Nabhikiya Vidyut Nigam, Ltd. (BHAVINI) to implement stage II.
- In stage III, Pu-239 will be combined with thorium-232 (Th-232) in reactors to produce energy and U-233.
- Homi J. Bhabha designed the three-stage programme because India hosts roughly a quarter of the world’s thorium. The three stages are expected to make the country completely self-sufficient in nuclear energy.
Why was the PFBR delayed?
- The PFBR saga in India has been associated with numerous delays, cost overruns, and broken promises, and has accrued many critics.
- The fast breeder test reactor (FBTR) at Kalpakkam is a testing ground for PFBR technologies. It was built by 1977 but sanctions against India’s ‘Smiling Buddha’ nuclear test forced the use of a mixed carbide fuel over enriched uranium (which France was to deliver).
- The former lowered the power output and changed operating conditions. By the time the Indian government green-lit the PFBR in 2003, most people who worked on the FBTR were also nearing or had completed retirement.
- The Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, designed the PFBR. Its original cost was ₹3,492 crore and the original deadline, 2010. Six years later, the DAE sought more funds and an extended deadline, which the government granted in 2012 ₹5,677 crore and commercial operations by March 2015.
- The nuclear power establishment further pushed the deadline to the next year, then the year after that, and so on until by March 2020, the new deadline to commercialise was October 2022.
How does the PFBR work?
- PHWRs use natural or low-enriched U-238 as the fissile material and produce Pu-239 as a byproduct.
- This Pu-239 is combined with more U-238 into a mixed oxide and loaded into the core of a new reactor together with a breeder blanket. This is a material the fission products in the core react with to produce more Pu-239.
- A breeder reactor is a nuclear reactor that produces more fissile material than it consumes. In a ‘fast’ breeder reactor, the neutrons aren’t slowed, allowing them to trigger specific fission reactions.
- The PFBR is designed to produce more Pu-239 than it consumes. It uses liquid sodium, a highly reactive substance, as coolant in two circuits.
- Coolant in the first circuit enters the reactor and leaves with (heat) energy and radioactivity. Via heat-exchangers, it transfers only the heat to the coolant in a secondary circuit. The latter transfers the heat to generators to produce electricity.
What role can SMRs play?
- The delays brooked another potential complication in the form of Small Modular Reactors (SMRs).
- These reactor designs have a maximum capacity of 300 MW, require less land, and accommodate more safety features.
- SMRs can work with low-enriched uranium, which India can import from the U.S. via its 123 Agreement.
- Increasing SMRs’ contribution would require, among other things, amendments to the Atomic Energy Act (1962) “and other related statutes” to allow private sector participation “under the oversight of the Atomic Energy Regulatory Body (AERB), with both nuclear fuel and waste controlled by the DAE” according to international safeguards.
What is the value of stage II?
- The PFBR has a capacity of 500 MWe. In 2019, the DAE proposed building four more fast breeder reactors (FBRs) of 600 MWe capacity each, two in Kalpakkam from 2021 and two from 2025, with sites to be selected.
- Today, the tariff for solar electricity is under ₹2.5/kWh whereas nuclear electricity costs around ₹ 4/kWh. The 2011 Fukushima Daiichi disaster also shifted public opinion worldwide against nuclear power, slowing work on new facilities.
- Today nuclear power has a new lease of life thanks to the pressure on India to decarbonise, reduce its import of fossil fuels, and give its renewable sector some breathing space.
What are the challenges of stage II?
- FBRs are harder to handle than other reactor designs, whereas the DAE has acquired an unfavourable public reputation over its often heavy-handed response to safety concerns.
- Further, the civilian nuclear programme’s nodal regulatory body, the AERB, was set up by executive order and reports ultimately to the DAE secretary. In 2015, the International Atomic Energy Agency urged India to set up an independent statutory atomic regulator instead.
- The DAE had responded to similar concerns with the Nuclear Safety Regulatory Authority (NSRA) Bill in 2011. It sought to replace the AERB with the NSRA. But it was criticised for allowing the Union government too much control over the NSRA’s composition.
- Finally, among other products, the thorium fuel cycle produces caesium-137, actinium-227, radium-224, radium-228, and thorium-230, all isotopes radioactive in ways that complicate their handling and storage.
