The document discusses three main types of nuclear reactors: boiling water reactors (BWR), pressurized water reactors (PWR), and gas-cooled reactors. It provides details on the basic design and operation of BWRs and PWRs, including their primary advantages and disadvantages. For BWRs, water is flashed directly to steam in the core and piped to a turbine, while PWRs use a primary and secondary water loop to prevent boiling in the core. Gas-cooled reactors use graphite as a moderator and gases like CO2 or helium as coolants.

1. PWR,BWR,GAS-COOLED
REACTOR
GROUP MEMBERS:-
1. UTSAV PRAJAPATI (13BME091)
2. YASH PATEL (13BME087)
3. YATIN PATEL (13BME088)
4. SHUBHAM PRAJAPATI (13BME090)

2. Nuclear Power Plant
Main Component:-
1. Nuclear Reactor
2. Heat Exchanger
3. Steam Turbine
4. Condenser
5. Electric Generator

3. BWR-Boiling Water Reactor
 In a Boiling Water Reactor (BWR), water in the core is flashed directly to steam.
 The steam is piped to a turbine/generator, where it is converted to electricity for use by the
grid.
 The unused steam that exits the turbine/generator is changed back into water in a condenser
and pumped back to the reactor vessel to complete the cycle.

4. BWR

5. BWR
Advantages:-
No heat exchanger ,Gain in thermal efficiency and cost
Lower pressure vessel for reactor which reduces cost
BWR is more efficient than PWR
Outlet temperature of steam is appreciably higher
Pressure inside of the pressure vessel is not so high so thicker vessel is not required

6. BWR
Disadvantages:-
Possibility of radioactive element in turbine mechanism
More elaborate safety precautions needed which are costly
Wastage of steam lowering the thermal efficiency on part load operation
3 to 5% by mass can be converted to steam per pass through the boiler
Possibility of burn out of fuel is more than PWR

7. PWR-Pressurised Water Reactor
 Primary Loop
◦ Water is heated in the reactor core and pumped through steam generator tubes, where it gives up heat to the
secondary side water, causing it to flash to steam.
◦ Water in the primary loop is maintained at a high temperature and pressure to prevent unwanted boiling in
the core.
 Secondary Loop
◦ The secondary loop in a PWR takes the water that flashes to steam around the outside of the tubes in the
steam generator and pipes it to a turbine/generator, where it is converted to electricity for use by the grid.
◦ The unused steam that exits the turbine/generator is changed back into water in a condenser and pumped
back to the steam generator to complete the cycle.
 In a PWR, the primary and secondary water never come in direct contact with each other.
 As a result of this, the secondary side steam and water are not radioactive as they are in a Boiling
Water Reactor.

8. PWR

9. PWR
Advantages:-
Water used in reactor is cheap and easily availible
Compact and high power density
Fission product remain contained
Complete freedom to inspect and maintain the turbine, feed heater and condenser during
operation
Extracting more energy per unit weight of fuel

10. PWR
Disadvantages:-
Capital cost is high as primary circuit requires strong pressure vessel
In the Secondary circuit the thermodynamic efficiency of this plant is quite low
Severe corrosion problems
Shut down the reactor for fuel charging which requires couple of month’s time
Fuel element fabrication is expensive

11. Gas-Cooled Reactor
Coolant : Gas , CO2 and Helium are preferable.
Moderator : Graphite ( 20% of the Nuclear Power Plants)
Fuel : Natural Uranium
Technologies : Magnox (Magnesium Alloy-UK) and UNGG(Uranium
natural Graphite Gas-FRANCE)
Coolant gas supplied by circulator.
Gas circulates from Bottom to Top and gets heated.

12. Gas-Cooled Reactor

13. Gas-
Cooled
reactor
Gas Cooled Graphite
Moderator Reactor
(GCGM)
Fuel : Natural Uranium
Coolant pressure : 7 bar
Coolant temperature : 336 ͦC
High Temperature Gas
Cooled Reactor
(HTGC)
Fuel : Uranium carbide + thorium
carbide (clad with graphite)
Coolant pressure : 15 to 30 bar
Coolant temperature : 700 ͦC to
800 ͦC
Gas
Cooled
Reactor
Gas Cooled Graphite
Moderator Reactor
(GCGM)
High Temperature Gas
Cooled Reactor
(HTGC)

14. Gas-Cooled Reactor
Advantages:-
1. Simple Fuel Process
2. No corrosion
3. Graphite – stable at high temperature
4. CO2 eliminates the possibilities of explosion
5. Uranium carbide and graphite : resist high temperature

15. Gas-Cooled Reactor
Disadvantages:-
1. Fuel : More Quantity and costly
2. Power density : very low
3. More Fuel (initially) : High Critical Mass
4. More power for coolant circulation
5. Complicated consolation