Which materials comprise typical fuel pellets and cladding in light-water reactors?

Which materials comprise typical fuel pellets and cladding in light-water reactors?

• A. Pellets: PuO2; Cladding: Stainless steel.
• B. Pellets: UO2; Cladding: Aluminum.
• C. Pellets: UO2; Cladding: Zircaloy.
• D. Pellets: MOX; Cladding: Zircaloy.

Answer: (C)

In light-water reactors, the typical fuel consists of uranium dioxide, UO2, because of its high melting point, stability, and favorable neutronic properties in a water reactor. The fuel is enclosed by a zirconium-based alloy cladding, commonly Zircaloy, chosen for its very low neutron absorption and good corrosion resistance in high-temperature water. Mixed-oxide fuel (MOX) can be used in some reactors, but it’s not the standard, so pellets made of MOX are not the usual pairing. Aluminum would not be used for cladding due to poor corrosion resistance in reactor water, and stainless steel cladding has higher neutron absorption and other drawbacks for normal LWR operation. Thus, the representative combination is uranium dioxide pellets with Zircaloy cladding.

In light-water reactors, the typical fuel consists of uranium dioxide, UO2, because of its high melting point, stability, and favorable neutronic properties in a water reactor. The fuel is enclosed by a zirconium-based alloy cladding, commonly Zircaloy, chosen for its very low neutron absorption and good corrosion resistance in high-temperature water. Mixed-oxide fuel (MOX) can be used in some reactors, but it’s not the standard, so pellets made of MOX are not the usual pairing. Aluminum would not be used for cladding due to poor corrosion resistance in reactor water, and stainless steel cladding has higher neutron absorption and other drawbacks for normal LWR operation. Thus, the representative combination is uranium dioxide pellets with Zircaloy cladding.