Which operational practice is commonly associated with CANDU reactors?

Which operational practice is commonly associated with CANDU reactors?

• A. Online refueling capability.
• B. Use of enriched uranium fuel.
• C. Gas-cooled operation.
• D. No online refueling.

Answer: (A)

Online refueling is tied to CANDU’s design: a network of horizontal pressure tubes containing fuel inside a heavy water moderator. Because the fuel channels can be isolated and accessed individually, fresh fuel can be inserted and spent fuel removed without shutting the whole reactor down. The heavy-water moderator provides excellent neutron economy, allowing natural uranium fuel to sustain fission and supporting this on-line fueling approach. This combination is what makes refueling while the reactor is operating a common practice for CANDU. The other options don’t fit: CANDU uses natural uranium rather than enriched fuel; it is not a gas-cooled reactor; and the ability to refuel online contradicts the statement of “no online refueling.”

Online refueling is tied to CANDU’s design: a network of horizontal pressure tubes containing fuel inside a heavy water moderator. Because the fuel channels can be isolated and accessed individually, fresh fuel can be inserted and spent fuel removed without shutting the whole reactor down. The heavy-water moderator provides excellent neutron economy, allowing natural uranium fuel to sustain fission and supporting this on-line fueling approach. This combination is what makes refueling while the reactor is operating a common practice for CANDU.

The other options don’t fit: CANDU uses natural uranium rather than enriched fuel; it is not a gas-cooled reactor; and the ability to refuel online contradicts the statement of “no online refueling.”