India’s 3-Stage Nuclear Program

Context:

Recently, the Indian PM witnessed the start of the process of core-loading the indigenous prototype fast breeder reactor (PFBR) at the Madras Atomic Power Station in Kalpakkam, Tamil Nadu. This is a historic milestone, marking entry into the vital second stage of India’s three stage nuclear program.

Relevance:

GS III: Science and Technology

Dimensions of the Article:

1. India’s Three-Stage Nuclear Program: A Strategic Overview
2. Functioning of PFBR (Stage II) – A Breeder Reactor
3. Reasons for PFBR (Stage II) Delay
4. Challenges for Stage II in India’s Nuclear Program:

India’s Three-Stage Nuclear Program: A Strategic Overview

• Conceptualized by physicist Homi Bhabha in the 1950s, India’s nuclear program aims at ensuring long-term energy security, independence, and sustainable development.
• The program focuses on utilizing uranium and abundant thorium reserves.

The Three Stages:

Natural Uranium-PHWRs:

• Initial phase involves Pressurised Heavy Water Reactors (PHWRs) using natural uranium fuel.
• Heavy water (deuterium) slows neutron reactions, producing plutonium-239 (Pu-239) and energy.
• Addresses India’s limited global uranium reserves (~1-2%).

Fast Breeder Reactors (FBRs):

• Second stage employs Fast Breeder Reactors using Pu-239 and U-238 to generate energy, U-233, and additional Pu-239.
• Special-purpose vehicle BHAVINI, established in 2003, oversees stage II implementation.

Thorium Utilization:

• Third phase integrates Pu-239 with thorium-232 (Th-232) to produce energy and U-233.
• Thorium crucial for India with substantial global reserves (~25%).

Thorium Challenges:

• Thorium utilization is complex, requiring breeding, and faces economic challenges due to low global uranium prices.

Department of Atomic Energy (DAE):

• Conducts indigenous R&D aligned with the three-stage nuclear power program.

Outcome:

• Aims for complete self-sufficiency in nuclear energy, leveraging India’s thorium resources.

Functioning of PFBR (Stage II) – A Breeder Reactor:

Breeder Reactor Concept:

• A breeder reactor generates more fissile material than it consumes.
• In a ‘fast’ breeder reactor, neutrons remain fast, enabling specific fission reactions.

PHWRs and Pu-239 Production:

• PHWRs utilize natural or low-enriched U-238 as fissile material.
• Pu-239 is produced as a byproduct.

Mixed Oxide Formation:

• Pu-239 is combined with additional U-238, forming a mixed oxide.
• Loaded into the new reactor’s core along with a blanket.

Fission Reaction in the Core:

• Core’s fission products react with the mixed oxide, producing more Pu-239.

Coolant System with Liquid Sodium:

• PFBR employs liquid sodium as a highly reactive coolant in two circuits.
• First circuit absorbs heat and radioactivity from the reactor.
• Heat-exchangers transfer only the heat to the coolant in the secondary circuit.
• The latter transfers heat to generators, generating electricity.

Thorium-232 Utilization:

• Thorium-232, a non-fissile material, acts as a blanket in this stage.
• Through transmutation, Thorium produces fissile Uranium-233 for use in the third stage.

Role as a Stepping Stone:

• FBR serves as a crucial intermediary stage, paving the way for full utilization of India’s abundant thorium reserves.

Capacity and Expansion Plans:

• PFBR operates with a 500 MWe capacity.
• DAE proposed constructing four more FBRs with 600 MWe capacity each in 2019.
• Two FBRs planned in Kalpakkam from 2021, and two from 2025, with sites yet to be determined.

Reasons for PFBR (Stage II) Delay:

FBTR Construction and Sanctions:

• FBTR at Kalpakkam served as a PFBR technology testing ground.
• Built by 1977, sanctions post-India’s ‘Smiling Buddha’ nuclear test led to using mixed carbide fuel instead of enriched uranium from France, affecting power output and operating conditions.

Ageing Workforce and Audit Findings:

• Commencing PFBR in 2003, many FBTR personnel nearing retirement.
• 2014 CAG audit revealed BHAVINI’s improper handling of PFBR component purchases, heavy reliance on NPCIL, and technical challenges in reactor coolant.

Cost Escalation:

• PFBR costs surged to Rs 6,800 crore (2019) from the initial Rs 3,492 crore, with multiple deadline extensions.

Challenges for Stage II in India’s Nuclear Program:

FBR Handling Challenges:

• FBRs pose handling difficulties compared to other reactor designs.
• Thorium fuel cycle produces radioactive materials complicating handling and storage.

Regulatory Framework and Public Perception:

• International Atomic Energy Agency (IAEA) urged India for an independent statutory atomic regulator.
• Nuclear Safety Regulatory Authority (NSRA) bill aimed to replace Atomic Energy Regulatory Body (AERB) but faced criticism for central government control.
• Public concerns heightened globally post-2011 Fukushima Daiichi disaster, affecting nuclear power projects.

Economic Viability:

• Solar electricity costs less than nuclear electricity (Rs 2.5/kWh vs. Rs 4/kWh).

Global and Domestic Shifts:

• Fukushima disaster impacted public opinion against nuclear power.
• Despite challenges, India’s push for decarbonization and reduced fossil fuel imports is revitalizing the nuclear power sector.
• NPCIL aims to commission a nuclear power reactor annually from 2024 to support India’s energy goals.

-Source: The Hindu