Nuclear reactor system and metallic coolant composition

A system comprising:

• a nuclear reactor comprising:
• a pressure vessel defining:
• an upper region;
• a lower region arranged below the upper region;
• an upper seal slot interposed between the upper region and the lower region;
• and
• a lower seal slot aligned with and vertically offset from the upper seal slot along a vertical axis of the pressure vessel;
• a nuclear fuel arranged within the lower region of the pressure vessel and configured to heat a working fluid entering the pressure vessel, via a fission reaction;
• and
• a set of control rods configured to transition between the upper region and the lower region of the pressure vessel to moderate the fission reaction within the nuclear fuel;
• a metallic fluid:
• comprising:
• a first proportion of lead configured to decrease an effective melting temperature of the metallic fluid and absorb gamma radiation emitted by the nuclear fuel;
• a second proportion of bismuth configured to absorb gamma radiation emitted by the nuclear fuel and to increase an effective boiling temperature of the metallic fluid;
• and
• a third proportion of cadmium configured to absorb neutron radiation emitted by the nuclear fuel;
• in a liquid state within an operating temperature range of the nuclear reactor;
• and
• configured to:
• occupy an interstitial volume between a shield and the pressure vessel;
• and
• absorb radiation emitted by the nuclear reactor;
• a first melt seal:
• arranged in the upper seal slot of the pressure vessel;
• configured to retain a volume of the metallic fluid within the interstitial volume between the shield and the pressure vessel during operation of the nuclear reactor;
• and
• configured to unseal from the upper seal slot to release metallic fluid, in the volume of the metallic fluid, into the lower region of the pressure vessel, the volume of the metallic fluid displacing the working fluid away from the nuclear fuel, in response to temperatures within the pressure vessel exceeding the operating temperature range;
• and
• a second melt seal:
• arranged in the lower seal slot of the pressure vessel;
• configured to cooperate with the first melt seal to retain the volume of the metallic fluid within the interstitial volume between the shield and the pressure vessel during operation of the nuclear reactor;
• and
• configured to unseal from the lower seal slot to release metallic fluid, in the volume of the metallic fluid, into the lower region of the pressure vessel in response to temperatures within the pressure vessel exceeding the operating temperature range.

A system comprising:

• a nuclear reactor comprising:
• a pressure vessel defining:
• an upper region;
• a lower region arranged below the upper region;
• a first seal slot interposed between the upper region and the lower region;
• and
• a second seal slot aligned with and vertically offset from the first seal slot along a vertical axis of the pressure vessel;
• and
• a nuclear fuel arranged within the lower region of the pressure vessel and configured to heat a working fluid entering the pressure vessel, via a fission reaction;
• and
• a metallic fluid:
• comprising:
• a first proportion of lead configured to decrease an effective melting temperature of the metallic fluid and absorb gamma radiation emitted by the nuclear fuel;
• a second proportion of bismuth configured to absorb gamma radiation emitted by the nuclear fuel and to increase an effective boiling temperature of the metallic fluid;
• and
• a third proportion of cadmium configured to absorb neutron radiation emitted by the nuclear fuel;
• in a liquid state within an operating temperature range of the nuclear reactor;
• and
• configured to:
• occupy an interstitial volume between a shield and the pressure vessel;
• and
• absorb radiation emitted by the nuclear reactor;
• and
• a first melt seal:
• arranged in the first seal slot of the pressure vessel;
• configured to retain metallic fluid within the interstitial volume between the shield and the pressure vessel during operation of the nuclear reactor;
• and
• configured to unseal from the first seal slot to release metallic fluid into the lower region of the pressure vessel in response to temperatures within the pressure vessel exceeding the operating temperature range to displace the working fluid away from the nuclear fuel;
• and
• a second melt seal:
• arranged in the second seal slot of the pressure vessel;
• configured to retain metallic fluid within the interstitial volume between the shield and the pressure vessel during operation of the nuclear reactor;
• and
• configured to unseal from the second seal slot to release metallic fluid into the lower region of the pressure vessel in response to temperatures within the pressure vessel exceeding the operating temperature range to displace the working fluid away from the nuclear fuel.