6. Containment building
it is the building in which reactor is located,
It is designed such as if in any emergency, to
contain the escape of radioactive steam or
gas to a maximum pressure in the range of 40
to 80 psi ( 410 to 1400 kPa)
Materials used
reinforced steel or lead structure
8. Reactor vessel :
It is an apparatus in which heat is produced
due to nuclear fission chain reaction for the
generation of electricity.
Materials used
1.SA508 Gr.3 Class 1,2 (Manganese-Molybdenum alloy)
2.Inconel 617 (Clad) (nickel-chromium-iron) alloy
3. 8 5/8 inches caebon outer boundry shield
These are alloys and they are oxidation and corrosion
resistant materials well suited for service in extreme
environments subjected to pressure and heat
9. Main Components
1. Reactor Core
It consists of fuel elements, control rods, coolant,
moderator and pressure vessels. Cores generally have
shapes of right circular cylinders with diameters
ranging from .5 to 15 metres.
Material used
Fuel rods made of uranium rods clod in thin sheath of
stainless steel, zirconium or aluminium.
11. 2. Reflector
It is placed round the core, to reflect back
some of the neutrons that leak out from core
surface.
Material used
Tungsten carbide
12. 3. Control Rods
It is made up of heavy mass element . It
simply absorb the neutrons so that it can
either maintain or stop a reaction.
Material used
Cadmium,lead etc.
13. 4. 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.
Material used
1.Water H2O.
2.Heavy water D2O.
3.Graphite.
4.Beryllium.
14. Properties of Moderator
High slowing down power
Non corrosiveness
Chemical and radiation stability
High thermal stability
D2O is best for moderator.
15. 5. Coolant
Coolant is used to remove intense heat produced in the
reactor and that heat can be transferred to water in a
separate vessel
which is converted into steam and runs the turbine.
Material used
Hg
He
CO2
H2O
16. 6.Shielding
Shielding is required to protect the working
men from the harmful effects of the
radiation.
In fission, alpha particles, beta particles,
gamma rays, slow and fast neutrons are
formed in which gamma rays and fast
neutrons are of main significance.
17. Materials used
To provide protection against them, thick
layers of lead or concrete provided round the
reactor.
Thick layers of metals or plastics are
sufficient to stop alpha and beta particles.
18. Spent nuclear fuel
storage
a method of storing high-level radioactive
waste that has already been cooled
Spent fuel pool
