NUCLEAR ROCKET ENGINE

NUCLEAR ROCKET ENGINE

In nuclear rocket, nuclear energy is used to heat the propellant or working fluid to get high temperature in the combustion chamber. Liquid hydrogen is widely used as a propellant. The combustion chamber consists of nuclear fission reactor, reflector, moderator, control rods, etc.

Parts of Nuclear Rocket Engine

1. Nuclear Reactor

It is an apparatus in which heat is produced due nuclear fission chain reaction. Nuclear reactors are used at nuclear power plants for electricity generation, propulsion of ships and also in nuclear thermal Rocket Propulsion system.

Components of Nuclear reactor

1. Reflector - Reflects neutrons produced in the reaction back into the core. It's Prevents neutron leakage & maintains reaction balance.

2. Shielding - Shielding is required to protect the working men from the harmful effects of the radiation.

3. Moderator - To slow down neutrons from high velocities and hence high energy level which they have on being released from fission process so that probability of neutron to hit the fuel rods increases.
Main moderator used:
1.Water H2O.
2.Heavy water D2O(Deuterium oxide).
3.Graphite.
4.Beryllium.

4. Fuel Element - It's contains the fissile fuel. usually Uranium or Plutonium.

5. Control Rods - It's contains material that absorbs neutrons & decreases and controls neutron production. It's also controls reaction rate. When it's fully inserted, they can shut down the reactor.
Examples- Cadmium, lead etc.

2. Turbine - A turbine is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work.

3. Pump- A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action.

3. Nozzle- A nozzle is a device designed to control the direction or characteristics of a fluid flow (especially to increase velocity) as it exits (or enters) an enclosed chamber.

Working

Liquid hydrogen from the propellant tank is pumped to a nuclear reactor through control valves. When the propellant passes through reactor tubes, it gets heated. This process produces gases of very high temperature and pressure. The highly heated products of combustion gases are then allowed to expand in nozzle section.

In the nozzle, pressure energy of the gas is converted into kinetic energy. So the gases coming out from the unit with very high velocity Due to high velocity of gases coming out from the unit, a force (or) thrust is produced in the opposite direction. This thrust propels the rocket.

A small portion of the heated gas from the combustion chamber is passed over the turbine which is used to drive the propellant pump. The turbine exhaust is expanded in a small nozzle which is also used to propel the rocket.

Types of Nuclear Rocket

1. Solid Core Nuclear thermal Rocket
2. Gas Core Nuclear thermal Rocket
3. Nuclear Power Electric Rocket
4. Nuclear Pulse Rocket

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