Shielded electromagnetic pumps for nuclear reactors

An electromagnetic pump (EMP), comprising:

• a pump casing having a longitudinal axis extending in a longitudinal direction, the pump casing at least partially defining an interior of the EMP;
• concentric inner and outer flow ducts extending coaxially with the longitudinal axis and collectively defining a flow annulus extending coaxially with the longitudinal axis;
• and
• a plurality of induction coils within the interior of the EMP and configured to be electrically connected to a power supply, the plurality of induction coils configured to control a flow of liquid metal coolant through the flow annulus based on electrical power received from the power supply,
• wherein at least the outer flow duct includes a gamma shielding material that is configured to block gamma rays emitted from the liquid metal coolant flowing through the flow annulus from entering the interior of the EMP from the flow annulus,
• wherein
• the outer flow duct includes first concentric cylindrical duct walls defining a first duct annulus between the first concentric cylindrical duct walls, the first concentric cylindrical duct walls including a first outer cylindrical duct wall and a first inner cylindrical duct wall, the first concentric cylindrical duct walls defining the first duct annulus between an inner surface of the first outer cylindrical duct wall and an outer surface of the first inner cylindrical duct wall, an inner surface of the first inner cylindrical duct wall partially defining the flow annulus,
• the gamma shielding material is in the first duct annulus between the first outer cylindrical duct wall and the first inner cylindrical duct wall, such that the first inner cylindrical duct wall is between the gamma shielding material and the flow annulus, and
• the gamma shielding material is a filler material in the first duct annulus.