Small Modular & Advanced Reactors

The IAEA describes small reactors as those up to about 300 MWe per unit and medium reactors up to about 700 MWe. Small modular reactors use standard designs built largely as factory modules and shipped to site, with several units sharing one plant.

Most SMR designs rely on passive safety: natural circulation, gravity-fed water and large heat sinks remove decay heat without pumps or operator action for days. A smaller core also means less radioactive inventory and a smaller potential emergency planning zone, subject to regulatory approval.

In the reactor core, uranium (or plutonium or uranium-233 bred from thorium) nuclei split when they absorb neutrons, releasing about 200 MeV of energy per fission as heat. A coolant carries this heat away to raise steam or heat a gas that drives a turbine.

Many light-water SMRs are integral designs: the core, steam generators and pressuriser sit inside one reactor pressure vessel, removing large external coolant pipes.

India has limited uranium but some of the world's largest thorium resources. Its long-standing three-stage nuclear programme links reactor types to make use of both.

Fuel choice also drives the spent-fuel route: India follows a closed fuel cycle, reprocessing spent fuel to recover plutonium and uranium.

Site selection weighs geology, seismicity, flooding, cooling water, population distribution, grid access and security. Retiring coal plants are widely studied as SMR sites because they already have land, water, transmission and a skilled workforce.

SMRs can supply steam or high-temperature heat as well as electricity, which opens uses beyond the grid.

In India nuclear power has been governed by the Atomic Energy Act, 1962, under which generation has been carried out by government companies such as NPCIL and joint ventures with public sector firms. Nuclear liability is set by the Civil Liability for Nuclear Damage Act, 2010.

The Government has announced a Nuclear Energy Mission with support for SMR research and an intent to open wider participation, including private investment, through changes to the legal framework. This framework is evolving; the current position must be checked before any commitment.

Nuclear plants operate under strict licence conditions, with trained and licensed staff, a strong safety culture and continuous regulatory oversight.

Nuclear projects are capital-heavy with very low fuel cost, so the cost of capital and construction risk decide the tariff.

BARREL works alongside licensed operators, reactor vendors and specialist consultants, supporting industries and owners on the non-nuclear scope and the project as a whole.