Which is the first-generation British reactor that uses CO2 as coolant with water as a secondary and uses natural uranium?

Which is the first-generation British reactor that uses CO2 as coolant with water as a secondary and uses natural uranium?

• A. AGR Reactor
• B. FNR Reactor
• C. Light Water Reactors
• D. Magnox Reactor

Answer: (D)

This item is about early UK reactor designs and how they were cooled, moderated, and fueled. Magnox reactors were the first generation built in Britain. They used natural uranium metal as fuel, with a graphite moderator to slow neutrons. The primary coolant was carbon dioxide gas circulating through the core to remove heat. The heat carried by the CO2 was transferred to a secondary loop where water circulated to generate steam for the turbines. That combination—CO2 as the primary coolant, water as the secondary coolant to make steam, and natural uranium fuel—defines the Magnox design. The other options don’t fit this specific mix: fast reactors used liquid sodium, not CO2; light-water reactors use water as both coolant and moderator and weren’t the first generation in Britain; advanced gas-cooled reactors use CO2 but rely on enriched uranium.

This item is about early UK reactor designs and how they were cooled, moderated, and fueled. Magnox reactors were the first generation built in Britain. They used natural uranium metal as fuel, with a graphite moderator to slow neutrons. The primary coolant was carbon dioxide gas circulating through the core to remove heat. The heat carried by the CO2 was transferred to a secondary loop where water circulated to generate steam for the turbines. That combination—CO2 as the primary coolant, water as the secondary coolant to make steam, and natural uranium fuel—defines the Magnox design. The other options don’t fit this specific mix: fast reactors used liquid sodium, not CO2; light-water reactors use water as both coolant and moderator and weren’t the first generation in Britain; advanced gas-cooled reactors use CO2 but rely on enriched uranium.