How does a nuclear reactor go critical?

Criticality is the normal operating condition of a nuclear reactor, in which nuclear fuel sustains a fission chain reaction. A reactor achieves criticality (and is said to be critical) when each fission releases a sufficient number of neutrons to sustain an ongoing series of nuclear reactions.

What is a molten salt fast reactor?

A molten salt reactor (MSR) is a class of nuclear fission reactor in which the primary nuclear reactor coolant and/or the fuel is a molten salt mixture. Only two MSRs have ever operated, both research reactors in the United States.

How do you make a reactor critical?

So when the control rods are fully inserted into the core the reactor is shut down; to start up a reactor we pull the control rods out – at some point there will be enough fuel exposed to the neutrons that there will be a chain reaction; at this point the reactor will be critical.

What is critical mass?

critical mass, in nuclear physics, the minimum amount of a given fissile material necessary to achieve a self-sustaining fission chain reaction under stated conditions.

What do you do with molten salt?

Uses. Molten salts have a variety of uses. Molten chloride salt mixtures are commonly used as baths for various alloy heat treatments, such as annealing and martempering of steel. Cyanide and chloride salt mixtures are used for surface modification of alloys such as carburizing and nitrocarburizing of steel.

At which stage is a nuclear reactor said to be critical?

When a reactor’s neutron population remains steady from one generation to the next (creating as many new neutrons as are lost), the fission chain reaction is self-sustaining and the reactor’s condition is referred to as “critical”.

How does a nuclear reactor explode?

When a reactor is turned on, the uranium nuclei undergo nuclear fission, splitting into lighter nuclei and producing heat and neutrons. If they begin to melt the nuclear reactor core and the steel containment vessel, and release radiation into the environment, nuclear meltdown occurs.