Proton accelerator facility to come up in Visakhapatnam

S&T – ENERGY

• Andhra Pradesh is set to play a key role in advancing one of India’s most ambitious atomic science programmes, with plans to establish a high-energy proton accelerator system in Visakhapatnam as part of the country’s long-term nuclear research roadmap.
• The proposed facility would form a crucial component of India’s accelerator-driven systems to harness vast thorium reserves for nuclear energy.
• Once running, the facility will generate high-energy neutrons through spallation reactions to convert India’s abundant thorium into uranium fuel for reactors.
• Visakhapatnam was chosen for its strong technological ecosystem and proximity to the sea, providing ample cooling water for such high-energy systems.

Raja Ramanna Centre for Advanced Technology (RRCAT)

• RRCAT was established  in Indore, Madhya Pradesh, in 1984 under the Department of Atomic Energy
• It leads research in particle accelerators and laser technologies with applications in space, defence, communications, and medical science.
• It also runs experiment labs for industries, hospitals, and institutions.
• RRCAT’s linear accelerators power electron beam facilities are used to sterilise medical devices.

High-Energy Proton Accelerator System (HEPAS)

• A High-Energy Proton Accelerator System is a technology that uses electromagnetic fields to accelerate protons (positively charged particles from ionized hydrogen) to extremely high speeds, producing a powerful proton beam.
• How it Works

1. Acceleration of Protons
   • Protons are accelerated to very high speeds using strong electromagnetic fields inside an accelerator.
2. Target Collision (Spallation Reaction)
   • The high-energy proton beam is directed at a heavy metal target such as lead or bismuth.
   • The collision breaks the heavy atomic nucleus and releases a large number of neutrons.
   • This process is called a spallation reaction.
3. Neutron Production and Energy Generation
   • The neutrons produced can trigger nuclear fission reactions, which release energy.

Accelerator-Driven System (ADS)

• An Accelerator-Driven System (ADS) combines a proton accelerator with a sub-critical nuclear reactor.
• The reactor core cannot sustain a chain reaction on its own.
• It depends on external neutrons supplied from the spallation process.
• These neutrons maintain the fission reaction and generate energy.

Safety Advantage

• If the accelerator stops due to power failure or malfunction, the neutron supply stops instantly.
• Without neutrons, the chain reaction stops automatically.
• This prevents reactor meltdown, making ADS inherently safer than traditional reactors.

Need of ADS for India

1. Harnessing Thorium

• India possesses about 25% of the world’s thorium reserves.
• Natural thorium (Th-232) is fertile, not fissile, so it cannot directly sustain a nuclear chain reaction.
• When thorium absorbs a neutron, it converts into Uranium-233 (U-233), which is fissile and can produce energy.
• The high-energy neutrons from ADS help convert thorium into U-233, enabling large-scale electricity generation.

2. Nuclear Waste Management (Transmutation)

• Conventional nuclear reactors produce long-lived radioactive waste such as minor actinides.
• These remain hazardous for thousands of years.
• The high-energy neutrons in ADS can transmute this waste into shorter-lived or stable isotopes, reducing long-term nuclear waste problems.