Nuclear Waste Management: Techniques, and Conventions

Context

India recently started its Prototype fast breeder reactor (PFBR) into operation, progressing towards the second stage of its nuclear program. 

From Uranium to Thorium: India’s Nuclear Evolution

• In the second stage, India will use uranium and plutonium. 
• In stage III, India hopes to use thorium to produce nuclear power.
• However,  the large-scale use of nuclear power is accompanied by a complex problem of nuclear waste management.

What is Nuclear Waste?

• Nuclear waste is also known as radioactive waste. 
• It refers to materials containing radioactive isotopes that are no longer useful for their original purpose.
• In a fission reactor, atoms of certain elements are bombarded by neutrons.
  • When an atom’s nucleus absorbs a neutron, it becomes unstable and splits apart.
    • This process releases energy and forms nuclei of different elements.
• For instance, uranium-235 can split into barium-144, krypton-89, and three neutrons.
  • The resulting elements become nuclear waste if they cannot undergo further fission.

Nuclear Waste Management Conventions

• Bamako Convention: 

  • This treaty was framed by African nations to prohibit the import of hazardous waste(radioactive)  into Africa. 

• Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management: 

  • It is an international treaty of the International Atomic Energy Agency (IAEA).
    • It is an initial treaty on the international level to address the management of radioactive waste. 

• Convention on Nuclear Safety (CNS): 

  • It ensures that all nations with nuclear power plants prioritise safety. 
    • CNS makes fundamental safety principles that all states are to follow. The convention aimss to increase safety levels through regular meetings. 

Nuclear Waste Handling Techniques

• Spent Fuel Storage: 

  • Spent fuel is stored underwater for up to a few decades for cooling. Later, after cooling, it is transferred to dry casks for longer-term storage.
    • Ex: The U.S. had 69,682 tonnes of spent fuel (as of 2015), Canada had 54,000 tonnes (2016), and Russia had 21,362 tonnes (2014).

• Liquid Waste Treatment: 

  • “Nuclear power plants” treat liquid waste and release some of it into the environment after treatment.

• Vitrification: 

  • “High-level liquid waste contains nearly all of the fission byproducts created in the fuel. It is turned into a glass-like material called vitrification for storage.”

• Reprocessing: 

  • Reprocessing is a method to separate usable material from spent fuel. 

• Geological Disposal: 

  • Geological disposal waste includes sealing nuclear waste in special containers buried deep underground in granite or clay. 

Issues Associated With Nuclear Waste

• Radioactive Pollution:

  • Harmful Radiation: Nuclear waste contains radioactive materials that emit harmful radiation.
  • Pollution: Improper handling or leaks can pollute soil, air, and water, harming people and the environment.

• Storage Challenges:

  • Long-term Storage: High-level waste (HLW) stays dangerously radioactive for thousands of years.
    • Finding safe places for long-term storage and disposal is difficult.

• Safety Concerns:

  • Risk of failures in maintenance: Transporting and storing nuclear waste has a lot of risks, such as accidents (such as releasing toxic radioactive materials into the environment). 
    • Ensuring secure storage facilities is vital to prevent unauthorised access.
  • Ex.: The Waste Isolation Pilot Plant (WIPP) in the U.S. experienced an accident in 2014, releasing radioactive materials.

• Financial Burden:

  • High Cost: Building and maintaining safe waste facilities requires a lot of money.
    • Waste management imposed a cost of $1.6-7.1 per MWh of nuclear energy.

Nuclear Waste Management in India

• On-Site management: 

  • The waste produced at nuclear power stations during operation has low to intermediate levels of radioactivity and is handled on-site. 
    • These facilities are available at all nuclear power stations for waste treatment and storage. 

• Reprocessing:  

  • Reprocessing plants are in Trombay, Tarapur, and Kalpakkam, India, as per the International Panel on Fissile Materials report.  
    • Trombay facility processes 50 tonnes of spent fuel annually from two research reactors.
      • These research reactors produce plutonium. 

• Regular surveillance: 

  • All surrounding areas of nuclear power plants undergo regular monitoring for radiation levels.

• IAEA Safeguards: 

  • India follows International Atomic Energy Agency (IAEA) safeguards, ensuring the safe and secure handling of nuclear materials and waste.

Also Read: India’s Nuclear Energy Programme

News Source: The Hindu 

DOWNLOAD PDF