Clementine (nuclear reactor)

The mercury was circulated through the core and out to a mercury-water heat exchanger at a maximum flow rate of 0.15 litres per second (0.040 USgal/s) by an induction type electromagnetic pump with no moving parts.

[5] The reactor core was wrapped in a series of neutron reflectors and shielding structures, starting with a 15 cm (6 in.)

This entire assembly was surrounded and supported by a thick concrete shell that provided additional shielding.

Shutdown of the reactor involved simultaneously dropping the uranium blanket and inserting the two control rods into the center which absorbed neutrons and poisoned the reaction.

[6] Clementine operated successfully from 1946 until 1950 when the reactor was shut down to correct a problem with the control and shim rods.

At this time it was decided that all the primary objectives of Clementine had been achieved and the reactor was permanently shut down and dismantled.

One of the notable achievements of the Clementine project included measurements for the total neutron cross sections of 41 elements to a 10% accuracy.

Additionally, Clementine provided invaluable experience in the control and design of fast neutron reactors.

It was also determined that mercury was not an ideal cooling medium for this type of reactor due to its poor heat transfer characteristics.