Neptunium melting point

The Melting Point and the Density of Neptunium Metal. — A Micro... 

Neptunium is a silvery-white radioactive, heavy metal. Its melting point is 644°C, its boiling point is 3,902°C, and its density is 20.25g/cm. ... 

Neptunium is a silvery white metal with a melting point of 1,180°F (640°C) and a density of 20.45 grams per cubic centimeter, more than 20 times the density of water. 

In 900MWe units, the capsules are irradiated along the outer surface of the thermal shield assembly. In 1300 and 1450 MWe units, the capsules are directly attached to the core barrel. In the case of Chooz-A, the thermal shield assembly was removed in 1970 and the surveillance capsules were then located under the core. The capsules are equipped with neutron dosimeters and thermal monitors, with some variations according to the reactor series. In all cases, activation dosimeters of nickel, copper and cobalt, as well as fissile dosimeters of uranium-238 and neptunium-237 are used. This instrumentation is complemented by iron and cadmium-shielded cobalt dosimeters in most cases and, in the most recent plants, also by niobium dosimeters. Each capsule contains temperature detectors based on eutectic alloys with melting points generally of 304 and 310 °C. 

The Melting Point and Density of Neptunium Metal. A Micro Melting Point Apparatus for Metals, E.E Westrum Jr. and L. Eyring, J. Amer. Chem. Soc., 73,3399-3400 (1951). 

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