What are the two types of reactors used in the U.S.?

What are the two types of reactors used in the U.S.?

• A. Boiling Water Reactors (BWR) and Pressurized Water Reactors (PWR)
• B. Graphite-moderated reactors and fast breeder reactors
• C. Heavy water reactors and gas-cooled reactors
• D. Molten salt reactors and pebble bed reactors

Answer: (A)

In the United States, the two main designs used for commercial nuclear power are Boiling Water Reactors and Pressurized Water Reactors. Both are light-water reactors, meaning they use ordinary water as the coolant and neutron moderator, but they handle heat and steam differently. In a boiling water reactor, water boils inside the reactor vessel to produce steam that directly drives the turbine. In a pressurized water reactor, the water in the reactor is kept under high pressure to prevent boiling, and its heat is transferred to a separate secondary loop that generates the steam for the turbine. This separation of the cooling circuit in PWRs vs. the single-loop design in BWRs is a key practical difference. These two designs together make up the vast majority of the U.S. commercial fleet, while other reactor types exist in other contexts but aren’t the standard two used for power generation in the U.S.

In the United States, the two main designs used for commercial nuclear power are Boiling Water Reactors and Pressurized Water Reactors. Both are light-water reactors, meaning they use ordinary water as the coolant and neutron moderator, but they handle heat and steam differently. In a boiling water reactor, water boils inside the reactor vessel to produce steam that directly drives the turbine. In a pressurized water reactor, the water in the reactor is kept under high pressure to prevent boiling, and its heat is transferred to a separate secondary loop that generates the steam for the turbine. This separation of the cooling circuit in PWRs vs. the single-loop design in BWRs is a key practical difference. These two designs together make up the vast majority of the U.S. commercial fleet, while other reactor types exist in other contexts but aren’t the standard two used for power generation in the U.S.