Heavy Water Reactors ( HWR)

Why in News ? Israel has recently launched airstrikes on Iran’s Arak heavy water reactor, highlighting concerns about the potential production of plutonium for atomic weapons.

Relevance : Pre & Mains

Prelims: HWR/IAEA

Mains :  GS II- / GS 3 –Environment

• The strikes targeted several Iranian nuclear sites, including the Natanz enrichment facility, centrifuge workshops near Tehran, and laboratories in Isfahan.
• The International Atomic Energy Agency (IAEA) reiterated that nuclear facilities should not be military targets.

About Iran’s Heavy Water Reactor:

Arak Reactor

Location:

1. • Situated 250 km southwest of Tehran.

Purpose:

1. • Can produce plutonium, a key material for nuclear bombs, raising international concerns.

Current Status:

1. • Not operational; lacks uranium fuel.
   • No nuclear material release occurred during the recent strike.

Historical Background

• Iran secretly sought a nuclear weapon program after the 1980s Iran-Iraq war.
• Initial attempts to purchase a heavy water reactor from four nations failed, prompting Iran to construct its own facility.
• Similar heavy water reactors exist in India, Pakistan, and Israel.

Significance in Nuclear Deals:

• Became a contentious issue after the 2018 U.S. withdrawal from the Joint Comprehensive Plan of Action (JCPOA) (Iran nuclear deal).
• In 2019, Iran’s nuclear official Ali Akbar Salehi claimed Iran secretly bought extra parts for the reactor despite JCPOA restrictions.

IAEA Concerns

• Iran imposed restrictions on IAEA inspections, leading to the loss of “continuity of knowledge” about Iran’s heavy water production.

Why Heavy Water Reactors are Important?

Function:

• • Unlike light water reactors, heavy water reactors use deuterium oxide (heavy water) to slow down neutrons, enabling the use of natural uranium.
  • Capable of producing weapons-grade plutonium as a by-product.

Global Context:

• • Heavy water reactors are pivotal in nuclear energy and weaponization strategies.

Advantages

Widely Used: Most common type of reactor globally, including in the U.S., Europe, and Japan.

Fuel Availability: Uses enriched uranium, widely available through established supply chains.

Safety: Inherent safety mechanisms due to water acting as a coolant and neutron absorber.

Disadvantages:

High Fuel Cost: Requires uranium enrichment.

Waste Management: Produces spent nuclear fuel that requires long-term storage.

Not Optimal for Weaponization: Does not efficiently produce weapons-grade plutonium.

Advantages:

1. No Enrichment Required: Reduces fuel preparation costs.
2. Efficient Neutron Economy: Can sustain chain reactions with natural uranium.
3. Versatile: Can be used for both civilian and military purposes (e.g., plutonium production).

Disadvantages:

1. Cost of Heavy Water: Production and maintenance of heavy water are expensive.
2. Proliferation Risk: Can produce weapons-grade plutonium as a by-product.
3. Complex Design: Requires advanced infrastructure for operation.

Global Usage:

• Light Water Reactors:
  • Examples: Pressurized Water Reactors (PWRs), Boiling Water Reactors (BWRs).
  • Used in countries like the U.S., Japan, and South Korea.
• Heavy Water Reactors:
  • Example: CANDU reactors (Canadian Deuterium Uranium reactors).
  • Prominent in India, Canada, and Pakistan due to reliance on natural uranium.