In news
Small Modular Reactors (SMRs) are compact nuclear reactors designed to be:
- Factory-fabricated,
- Transportable,
- Modular (can be scaled up with multiple units),
- Generating up to 300 MWe per unit.
Why Thorium?
- India has abundant thorium reserves, especially monazite sands on the east coast.
- Thorium-232 is fertile, not fissile – it absorbs neutrons to become Uranium-233, a fissile material.
- Cleaner and safer: lower long-lived radioactive waste, better safety margins.
How it Works (Simplified)
- Thorium-232 absorbs a neutron → becomes Uranium-233 (fissile).
- U-233 sustains the chain reaction to produce energy.
- SMRs use advanced cooling systems (e.g., liquid salt, gas, or molten lead).
India’s Relevance
- Part of India’s 3-stage nuclear programme:
- Stage 1: Natural uranium reactors
- Stage 2: Fast breeder reactors
- Stage 3: Thorium-based reactors (Advanced Heavy Water Reactors – AHWR)
- SMRs can help decentralize power, especially in remote/rural areas.
- Aligns with India’s net-zero targets and energy security goals.
Advantages
- Safe design: Passive cooling, meltdown-resistant.
- Lower cost & faster deployment than large nuclear plants.
- Modular: Scalable according to local energy needs.
- Reduces GHGs and reliance on fossil fuels.
- Utilizes India’s thorium wealth.
Challenges
- Thorium fuel cycle is complex and not yet commercially proven.
- High initial R&D costs.
- Regulatory hurdles and public perception of nuclear safety.
- Long time to build the necessary uranium-233 inventory.
Pointers
- Thorium is not fissile → needs conversion to U-233
- India has ~25% of world’s thorium reserves
- SMRs: <300 MWe, modular, passive safety features
- AHWR: India’s indigenous thorium-based reactor design
Course Purchase Query 