Moderator Used In Nuclear Reactor Should Have Low Specific Heat

The amount of time between the discovery of new nuclear material and implementing it to be used in a nuclear reactor is pretty large.

What is nuclear energy bbc china nuclear leak. Nuclei with low mass numbers are most effective for this purpose so the moderator is always a low mass number material. Ordinary water is used in nuclear reactors as a moderator for a number of reasons. Commonly used moderators include regular light water roughly 75 of the worlds reactors solid.

The moderation of neutrons is undesirable in fast reactors. The low cost of water easy availability and excellent slowing down property makes it a fine neutron moderator. Ordinary water can be used as a moderator only if enriched uranium fuel is used.

Materials used for moderation need to a very specific set of properties. The natural uranium fuel is in the form of metal rods 25 cm in diameter. Most of the operating gas cooled power reactors are in the uk.

It can be employed as both a moderator and a coolant in the nuclear. Good moderator materials should have low neutron absorption cross section and can also act as a coolant if the moderator material has high heat capacity to absorb the heat from the reactor for example water. The early ones use a finned magnox cladding and co 2 coolant.

First a moderator cannot absorb neutrons itself. In nuclear engineering a neutron moderator is a medium that reduces the speed of fast neutrons ideally without capturing any leaving them as thermal neutrons with only minimal thermal kinetic energythese thermal neutrons are immensely more susceptible than fast neutrons to propagate a nuclear chain reaction of uranium 235 or other fissile isotope by colliding with their atomic nucleus. This means that the moderator should have a low neutron absorption cross section.