Small-scale commercial nuclear reactors, the way forward

The idea of putting up hundreds, if not thousands, of small-sized nuclear reactors designed for modular expansion so that they could be bulk-produced in factories and brought to the sites in containers, has been engaging the attention of energy experts for some years. It is increasingly being realised that achieving net-zero is not possible without nuclear energy.

In India, both government and industry are keen on small modular reactors (SMRs). The Centre’s keenness is borne out by Finance Minister Nirmala Sitharaman’s reference to ‘Bharat Small Reactors’ (BSR) in her Budget speech. Meanwhile, industry, especially steel, is reported to be examining the nuclear option for green energy. India has a head start over other countries in small reactors. It has been operating 15 pressurised heavy water reactors (PHWR) of 220 MW each, accounting for half of India’s 6780 MW nuclear power capacity, and 70 per cent if one excludes the 2000 MW of Russia-made Kudankulam plants. About 70 design concepts of SMRs are floating around but none has the proven safety record of PHWRs. Therefore, it is welcome that the government is considering modifying the PHWRs into BSRs — adding ‘passive safety’ features such as self-cooling and metal lining on the inner walls of the reactor so that the ‘exclusion zone’ outside the power plant can be at least halved to half a kilometre.

Also welcome is the government’s intention to modify the regulatory framework, bringing amendments to the Atomic Energy Act and the Civil Nuclear Liability Damage Act to make way for private participation. As the advent of BSRs is a turning point in India’s nuclear energy story, it is essential to think it through to get it right. Three points are worth keeping in mind. First, for nuclear power to aid India’s net zero ambitions, the country needs both BSRs and large nuclear plants. For better focus, a separate company for BSRs would be wise. This company may licence technology, deal with the private industry and push exports of BSRs, leaving Nuclear Power Corporation of India to pursue the larger nuclear plants.

Second, steps should be taken to achieve fuel independence. PHWRs throw up more spent fuel than light water reactors. Collecting and sequestering it is a massive undertaking and a proliferation risk. Fortunately, a new type of fuel, ANEEL (Advanced Nuclear Energy for Enriched Life), developed by an Indian-owned US company, could provide the solution to the fuel cycle. ANEEL, a combination of High Assay Low Enriched Uranium (HALEU) and thorium, offers a bouquet of advantages — lesser and proliferation risk-free spent fuel, use of India’s abundant thorium and high burn-up. The Indo-US civil nuclear deal could be leveraged for accessing ANEEL. Finally, India should not lose sight of the other SMR it has in its arsenal — the 300 MW Advanced Heavy Water Reactor (AHWR), which is technologically superior to PHWRs but with no track record. India should quickly build a prototype AHWR. The AHWR programme can co-exist with BSRs.