{"id":4209,"date":"2026-01-20T12:00:59","date_gmt":"2026-01-20T06:30:59","guid":{"rendered":"https:\/\/vajiramandravi.com\/upsc-exam\/?p=4209"},"modified":"2026-01-20T12:41:47","modified_gmt":"2026-01-20T07:11:47","slug":"small-modular-reactors","status":"publish","type":"post","link":"https:\/\/vajiramandravi.com\/upsc-exam\/small-modular-reactors\/","title":{"rendered":"Small Modular Reactors India, Capacity, Types, UPSC Notes"},"content":{"rendered":"<p>Small Modular Reactors are nuclear fission reactors with a power generation\u00a0<strong>capacity of up to 300 MW.<\/strong>These types of nuclear reactors are characterised by their simplicity of design, factor-assembled production capacity, scalability, modularity, standardisation, cost-effective operation, short construction duration, etc. SMRs are an innovative solution that has the potential to reshape power generation and usage.<\/p>\r\n<p>Nations around the world, including India, have committed to a Net Zero target for carbon emissions. In such a scenario, SMRs, despite having many practical challenges, can become a viable option for providing clean energy.<\/p>\r\n<h2>Small Modular Reactors Meaning<\/h2>\r\n<p>Based on power generation capacity, the International Atomic Energy Agency (IAEA)has defined\u00a0<strong>Small modular Reactors<\/strong>\u00a0as those nuclear power plants that produce electricity of up to 300 MW(e) per module, around one-third of the generation capacity of the traditional nuclear plants. The term SMR consists of\u00a0<strong>three terms<\/strong>\u00a0with independent meanings.<\/p>\r\n<ul>\r\n\t<li><strong>Small<\/strong>: It is about the physical size of (SMRs) which is just\u00a0<strong>much smaller than conventional nuclear power reactors<\/strong>.<\/li>\r\n\t<li><strong>Modular:<\/strong>\u00a0It is aboutmaking systems and components\u00a0<strong>factory-assembled and transported<\/strong>\u00a0as a unit to a location for installation.<\/li>\r\n\t<li><strong>Reactors:\u00a0<\/strong>It is about harnessing\u00a0<strong>nuclear fission<\/strong>\u00a0to generate heat to produce electrical energy.<\/li>\r\n<\/ul>\r\n<h2>Small Modular Reactors Working<\/h2>\r\n<p>The basic working principle of SMRs is similar to a typical nuclear fission reactor in controlled fission. Thus, there are three basic working steps of SMRs, being described below:<\/p>\r\n<ul>\r\n\t<li><strong>Heat generation:\u00a0<\/strong>Nuclear Power Plants generate heat through the\u00a0<strong>fission reaction <\/strong>taking place in the reactor core, releasing in a controlled manner.\r\n\r\n<ul>\r\n\t<li><strong>A controlled rod\u00a0<\/strong>absorbs the extra neutron to maintain a controlled chain reaction and provide sustained energy.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t<li><strong>Steam generation:\u00a0<\/strong>The Reactor\u2019s water coolant picks up heat from the reactor core. The coolant\u2019s pumps circulate this hot water through a steam generator, which converts water in a secondary loop into steam.<\/li>\r\n\t<li><strong>Mechanical energy to electrical energy:\u00a0<\/strong>Steam generated is used to derive turbines, which consequently convert to electrical energy.<\/li>\r\n<\/ul>\r\n<h2>Categories of Small Modular Reactors<\/h2>\r\n<p>As of now, only two SMR projects are in the operational stage globally -<strong>\u00a0Russia\u2019s Akademik Lomonosov plant\u00a0<\/strong>(a floating SMR) of\u00a0<strong>35 MW\u00a0<\/strong>capacity and\u00a0<strong>China\u2019s HTR-PM of 210 MW<\/strong>\u00a0capacity. Based on location, size, and coolant types, SMRs can be categorised into the following types:<\/p>\r\n<ul>\r\n\t<li><strong>Land-based water-cooled SMRs (PWRs):\u00a0<\/strong>\u00a0These include water-cooled SMR designs of various configurations of LWR (Light Water Reactors) and PHWR (Pressurised Heavy Water Reactors.\r\n\r\n<ul>\r\n\t<li><strong>Example:<\/strong>\u00a0RITM-200N (project stage) in Russia.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t<li><strong>Marine-based water-cooled SMRs (PWRs):<\/strong>\u00a0These include SMR designs for deployment in marine environments. This can be achieved in the form of floating units installed on barges or ships.\r\n\r\n<ul>\r\n\t<li><strong>Example: SMR KLT-40S<\/strong>, a floating SMR in Russia.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t<li><strong>High-temperature gas-cooled SMRs (HTGRs):\u00a0<\/strong>SMRs in this category can provide very high-temperature heat of more than 750\u00b0C, to be able to generate electricity at higher efficiency.\r\n\r\n<ul>\r\n\t<li>These SMRs can also be employed in many industrial applications and cogeneration.<\/li>\r\n\t<li><strong>Example: HTR-PM (China)<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t<li><strong>Liquid metal-cooled fast neutron spectrum SMRs (LMFRs):\u00a0<\/strong>They are based on fast neutron technology and use liquid metal coolants (sodium, lead, and lead-bismuth alloy) and Helium.\r\n\r\n<ul>\r\n\t<li><strong>Example: BREST\u00a0<\/strong>reactors (planned) in Russia<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t<li><strong>Molten Salt Reactor SMRs (MSRs):\u00a0<\/strong>They are based on molten fluoride or chloride salt coolants.\r\n\r\n<ul>\r\n\t<li>MSR based on both thermal neutron and fast neutron spectrums are in the development phase.<\/li>\r\n\t<li>MSRs can sustain longer fuel cycles of several years.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t<li><strong>Microreactors (MRs):\u00a0<\/strong>These are very small reactors that generate power\u00a0<strong>up to 10 MW(e).<\/strong>\r\n<ul>\r\n\t<li>Various coolant options such as light water, molten salt, and liquid metal can be adopted by microreactors.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<h2>Small Modular Reactors Significance<\/h2>\r\n<p>SMR-based power plants offer unique advantages in terms of safety, efficiency, economics, and flexibility of operation.<\/p>\r\n<ul>\r\n\t<li><strong>Advanced safety features:\u00a0<\/strong>SMRs are designed to include several\u00a0<strong>passive safety features<\/strong>\u00a0to ensure lower risks for the uncontrolled release of radioactive materials into the environment, during any accident.\r\n\r\n<ul>\r\n\t<li>It has a relatively smaller\u00a0<strong>core damage frequency\u00a0<\/strong>and\u00a0<strong>source term\u00a0<\/strong>compared to<strong>\u00a0conventional\u00a0<\/strong>Nuclear Power Plants.<\/li>\r\n\t<li><strong>Core damage frequency<\/strong>\u00a0is the likelihood that an accident can damage the nuclear fuel.\u00a0<strong>The source term\u00a0<\/strong>is a measure of radioactive contamination.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t<li><strong>Economical and efficient:<\/strong>\u00a0Serial manufacturing models for SMRs can simplify plant design to reduce manufacturing costs. Moreover, off-site development of SMRs further reduces the cost.\r\n\r\n<ul>\r\n\t<li><strong>Brownfield project:<\/strong>\u00a0SMRs can be installed into an\u00a0<strong>existing grid\u00a0<\/strong>or<strong>, a decommissioned thermal power plant<\/strong>, as a discrete unit of power generation.<\/li>\r\n\t<li><strong>SMRs overcome transportation limits:\u00a0<\/strong>80% of SMR plants can be modularised and transported by road due to their smaller size, compared to only 20% for large reactors.<\/li>\r\n\t<li><strong>Hybrid energy system:\u00a0<\/strong>SMRscan be paired with other sources of electric energy and increase the efficiency of renewable sources in a hybrid energy system.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t<li><strong>Reduced fuel requirement:\u00a0<\/strong>Power plants based on SMRs require refueling every 3 to 7 years in comparison to between 1 and 2 years for conventional nuclear power plants.\r\n\r\n<ul>\r\n\t<li>SMRs are designed to operate for up to 30 years without the need for refueling.<\/li>\r\n\t<li>Also,\u00a0<strong>SMRs are designed for low-enriched uranium<\/strong>.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t<li><strong>Decarbonising the power sector:\u00a0<\/strong>SMRs can play a meaningful role in reducing carbon emissions and can act as alternative sources of sustainable energy, better than conventional nuclear power plants.\r\n\r\n<ul>\r\n\t<li>It is also instrumental in attaining\u00a0<strong>Sustainable Development Goals<\/strong>\u00a0(SDGs) and helps to realise the goal of developing safe, clean, and affordable nuclear power options.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<h2>Challenges Associated with Small Modular Reactors<\/h2>\r\n<p>Along with their advantages and rising popularity, SMRs also face several regulatory, technical, and operational challenges.<\/p>\r\n<ul>\r\n\t<li><strong>Need for an efficient regulation regime:\u00a0<\/strong>The application of uniform regulation and safeguard standards across the world is crucial to the safe functioning of the overall ecosystem of SMRs.<\/li>\r\n\t<li><strong>Licensing challenge:\u00a0<\/strong>Newly developed SMR technologies may find it difficult to accommodate in the current\u00a0<strong>licensing regime.\u00a0<\/strong><\/li>\r\n\t<li><strong>Radioactive Radiation:\u00a0<\/strong>SMRs are said to produce more radioactive waste than conventional ones, mainly in the form of spent fuel.\r\n\r\n<ul>\r\n\t<li>This can lead to serious health hazards, such as mutations in genetic material.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t<li><strong>Potential nuclear disaster:\u00a0<\/strong>Nuclear power has faced opposition due to past nuclear hazards and potential disasters. In such a sceptical environment, convincing people to mainstream SMRs for decentralised power generation is a challenge.<\/li>\r\n<\/ul>\r\n<h2>Opportunities for India<\/h2>\r\n<p>The Indian Government has also acknowledged the advantages and opportunities of SMRs as a promising alternative to large reactors.<\/p>\r\n<ul>\r\n\t<li><strong>Carbon offsetting:\u00a0<\/strong>India has committed to achieve carbon neutrality by 2070. In such a scenario, various types of SMRs, such as microreactors, can be a viable option for offsetting carbon.<\/li>\r\n\t<li><strong>Utilisation of Decommissioned Power Plants<\/strong>: Indian public sector units such as NTPC, and BHEL, etc. can use decommissioned areas for the installation of SMRs as a viable alternative to large-scale reactors.<\/li>\r\n\t<li><strong>Distributed Generation: Microreactors and other SMRs<\/strong>\u00a0can accelerate access to energy infrastructure in hilly and remote areas, such as the\u00a0<strong>Northeastern region,<\/strong>\u00a0to fulfill energy needs.<\/li>\r\n\t<li><strong>Nuclear-powered Submarine:<\/strong>\u00a0Modular reactors can be a key technology for the development of nuclear submarines such as\u00a0<strong>INS-Arihant<\/strong><strong>,<\/strong>\u00a0thereby boosting India\u2019s Nuclear triad.<\/li>\r\n<\/ul>\r\n<p>The Government has been developing a roadmap for studying the feasibility and effectiveness of the deployment of SMRs. A report published by NITI Aayog emphasises the successful deployment of SMR technology, leveraging private sector inclusion.<\/p>\r\n<h2>Small Modular Reactors UPSC PYQs<\/h2>\r\n<p><strong>Question 1.\u00a0<\/strong>With growing energy needs should India keep on expanding its nuclear energy programme? Discuss the facts and fears associated with nuclear energy.\u00a0<strong>(UPSC-Mains 2018)<\/strong><\/p>\r\n<p><strong>Question 2.\u00a0<\/strong>The function of heavy water in a nuclear reactor is to (<strong>UPSC-Prelims 2011<\/strong>)<\/p>\r\n<p>(a) Slow down the speed of neutrons<br \/>\r\n(b) Increase the speed of neutrons<br \/>\r\n(c) Cool down the reactor<br \/>\r\n(d) Stop the nuclear reaction<\/p>\r\n<p><strong>Answer: (a)<\/strong><\/p>","protected":false},"excerpt":{"rendered":"<p>SMRs incorporate higher modularisation, standardization, and factory-based construction of a capacity of 300 MW to complement other means of eco-friendly electricity generation.<\/p>\n","protected":false},"author":6,"featured_media":4210,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[173],"tags":[40,195],"class_list":{"0":"post-4209","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-quest-level-3","8":"tag-quest","9":"tag-small-modular-reactors"},"acf":[],"_links":{"self":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/4209","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/comments?post=4209"}],"version-history":[{"count":3,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/4209\/revisions"}],"predecessor-version":[{"id":23297,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/4209\/revisions\/23297"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/media\/4210"}],"wp:attachment":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/media?parent=4209"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/categories?post=4209"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/tags?post=4209"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}