Reactor Classification

Date: 2015-10-07; view: 489.

Nuclear Reactor Arrangement

1. The main reactor components are the reactor core, reflector, pressure vessel, biological shielding.

2. The core contains nuclear fuel in the form of rods or plates, arranged in assemblies; the coolant, the moderator, the control rods.

3. The function of nuclear fuel is to release heat.

4. Nuclear fuel may be Uranium or Plutonium.

5. A gas, water or liquid metals used for coolant serve to absorb heat and to remove it to the heat exchanger.

6. Moderator is a neutron absorbing material used to slow down fast neutrons.

7. The moderator may be water, graphite or beryllium.

8. Pressure vessel, which is a heavy tank made of steel, contains all the reactor parts.

9. Reflector is a layer of moderating materials like water, graphite, beryllium used to reduce neutron leakage from the core.

10. Biological shielding is a layer of neutron absorbing materials like water, concrete, lead or iron used to protect personnel against radiation.

11. To control fission process in the core control rods made of boron or cadmium are used.

1. Nuclear reactors are classified by six principles.

2. They are: by the energy level of neutrons, by nuclear fuel, by purpose, by the arrangement of fuel and moderator, by the moderator used, by the coolant used.

3. By the energy level of neutrons, reactors are subdivided into fast, intermediate and thermal.

4. By nuclear fuelreactors are classified into natural uranium (with 0.7 % U235), slightly enriched U (with 1 – 2 % U235), highly enriched U (with 90 % U235), Pu239, U233.

5. By purpose there are power, research, prototype and production reactors.

6. By arrangement of fuel and moderator reactors are heterogeneous or homogeneous.

7. By the moderator used reactors are classified into heavy-water-moderated, light- water-moderated, graphite-moderated and beryllium-moderated.

8. By the coolant used reactors are divided into gas-cooled, organic-cooled, liquid metal-cooled and water-cooled.