Context: The Small Nuclear Reactors and Small Satelite Vehicles have increased the presence of private sector in these sectors, which may lead to cost efficient, environmentally sustainable and competitive future technologies.

Nuclear Fusion and Energy 

Nuclear fission is a reaction where the nucleus of an atom splits into two or more smaller nuclei, while releasing energy.

• For instance, when hit by a neutron, the nucleus of an atom of uranium-235 splits into two smaller nuclei, for example a barium nucleus and a krypton nucleus and two or three neutrons. 
• These extra neutrons will hit other surrounding uranium-235 atoms, which will also split and generate additional neutrons in a multiplying effect, thus generating a chain reaction in a fraction of a second.
• Each time the reaction occurs, there is a release of energy in the form of heat and radiation. 
• The heat can be converted into electricity in a nuclear power plant, similarly to how heat from fossil fuels such as coal, gas and oil is used to generate electricity.

Nuclear Power Plant Working 

• In a nuclear reactor heat is produced through the chain reaction happening through the fission.
• The heat warms the reactor’s cooling agent, typically water, to produce steam. 
• The steam is then channelled to spin turbines, activating an electric generator to create low-carbon electricity.

Small modular reactors (SMRs)

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.

Advantages of SMR 

• Given their smaller footprint, SMRs can be sited on locations not suitable for larger nuclear power plants.
• refabricated units of SMRs can be manufactured and then shipped and installed on site, making them more affordable to build than large power reactors, which are often custom designed for a particular location, sometimes leading to construction delays.
• SMRs offer savings in cost and construction time, and they can be deployed incrementally to match increasing energy demand.
• In areas lacking sufficient lines of transmission and grid capacity such as rural areas, 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.
• 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
• In comparison to existing reactors, proposed 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.

Small Satellite Launch Vehicle

• Small Satellite Launch Vehicle (SSLV) is the new launch vehicle of ISRO capable of launching Mini, Micro or Nano satellites (10 to 500 kg mass) to 500 km planar orbit. 
• SSLV is a three-stage vehicle with all solid propulsion stages. 
• The satellite insertion into the intended orbit is achieved through a liquid propulsion-based Velocity Trimming Module (VTM).

Advantages:

• Its has low production cost.
• It has a low turnaround time.
• It has high flexibility in accommodating multiple satellites.
• It has launch-on-demand feasibility.
• It needs minimal launch infrastructure requirements.
• The advantage of SSLVs is that each rocket can be integrated within as short a span of time as 72 hours, against more than a month taken for other launch vehicles.