SMALL MODULAR REACTORS (SMR)
WHAT ARE SMR ?
- Small modular reactors (SMRs) are advanced nuclear reactors that have a power capacity of up to 300 MW(e) per unit, which is about one-third of the generating capacity of traditional nuclear power reactors.
SMRs, which can produce a large amount of low-carbon electricity, are:
- Small – physically a fraction of the size of a conventional nuclear power reactor.
- Modular – making it possible for systems and components to be factory-assembled and transported as a unit to a location for installation.
- Reactors – harnessing nuclear fission to generate heat to produce energy.
FEATURES OF SMR:
- Small power and compact architecture and usually (at least for nuclear steam supply system and associated safety systems) employment of passive concepts. Therefore there is less reliance on active safety systems and additional pumps, as well as AC power for accident mitigation.
- The compact architecture enables modularity of fabrication (in-factory), which can also facilitate implementation of higher quality standards.
- Lower power leading to reduction of the source term as well as smaller radioactive inventory in a reactor (smaller reactors).
- Potential for sub-grade (underground or underwater) location of the reactor unit providing more protection from natural (e.g. seismic or tsunami according to the location) or man-made (e.g. aircraft impact) hazards.
- The modular design and small size lends itself to having multiple units on the same site.
- Lower requirement for access to cooling water – therefore suitable for remote regions and for specific applications such as mining or desalination.
- Ability to remove reactor module or in-situ decommissioning at the end of the lifetime.
ADVANTAGES OF SMR:
A World Nuclear Association 2015 report on SMR standardization of licensing and harmonization of regulatory requirements said that the enormous potential of SMRs rests on a number of factors:
- Because of their small size and modularity, SMRs could almost be completely built in a controlled factory setting and installed module by module, improving the level of construction quality and efficiency.
- Their small size and passive safety features lend them to countries with smaller grids and less experience of nuclear power.
- Size, construction efficiency and passive safety systems (requiring less redundancy) can lead to easier financing compared to that for larger plants.
- Moreover, achieving ‘economies of series production’ for a specific SMR design will reduce costs further.
- SMRs can be installed into an existing grid or remotely off-grid, as a function of its smaller electrical output, providing low-carbon power for industry and the population.
- SMR designs are generally simpler, and the safety concept for SMRs often relies more on passive systems and inherent safety characteristics of the reactor, such as low power and operating pressure.
- SMRs have reduced fuel requirements.
- Power plants based on SMRs may require less frequent refuelling, every 3 to 7 years, in comparison to between 1 and 2 years for conventional plants.
- Some SMRs are designed to operate for up to 30 years without refuelling.
HOW CAN SMRs BE INTEGRATED WITH THE NATIONAL GRID ?
- India’s Central Electricity Authority (CEA) projects that the generation capacity of coal based thermal power plants (TPPs) in India must be increased to 259,000 MW by 2032 from the current 212,000 MW.
- Also enhancing the generation capacity of VRE sources to 486,000 MW from 130,000 MW.
- Integrating this power from VRE sources with the national grid will require additional energy storage — to the tune of 47,000 MW/236 GWh with batteries and 27,000 MW from hydroelectric facilities.
- The CEA also projects that TPPs will provide more than half of the electricity generated in India by 2031-2032 while VRE sources and NPPs will contribute 35% and 4.4%, respectively.
CHANGES REQUIRED IN LEGAL AND REGULATORY FRAMEWORKS:
- The Atomic Energy Act will need to be amended to allow the private sector to set up SMRs.
- To ensure safety, security, and safeguards, control of nuclear fuel and radioactive waste must continue to lie with the Government of India.
- The government will also have to enact a law to create an independent, empowered regulatory board with the expertise and capacity to oversee every stage of the nuclear power generation cycle.
- The security around SMRs must remain under government control, while the Nuclear Power Corporation can operate privately owned SMRs during the handholding process.
- The Department of Atomic Energy must improve the public perception of nuclear power in India by better disseminating comprehensive environmental and public health data of the civilian reactors, which are operating under international safeguards, in India.
SYLLABUS: MAINS, GS-3, INFRASTRUCTURE
SOURCE: THE HINDU