PWR is the most common type of nuclear reactor, representing about 60% of all nuclear power reactors in the world. PWRs keep water under pressure so that it heats, but does not boil. Water from the reactor and the water in the steam generator that is turned into steam never mix. In this way, most of the radioactivity stays in the reactor area. Light Water Cooled

1. Naisarg Sagathiya
Sub:- Power Plant Engineering
Topic:- Pressurised Water
Reactor

2. Different Types of Reactors
• On the basis of Neutron Energy
(a) Fast Reactors (b) Thermal Reactors
• On the basis of Fuel Used
(a) Natural Fuels (b) Enriched Uranium
• On the basis of Moderator Used
(a) Water moderato (b) Heavy water
moderator
(c) Graphite moderator (d) Beryllium Moderated
• On the Basis of Coolant Used
(a) Water cooled (b) Gas Cooled
(c) Liquid metal cooled (d) Organic Liquid Cooled

3. Pressurised Water
Reactor(PWR)
• PWR is the most common type of nuclear
reactor, representing about 60% of all nuclear
power reactors in the world.
• PWRs keep water under pressure so that it
heats, but does not boil.
• Water from the reactor and the water in the
steam generator that is turned into steam
never mix. In this way, most of the
radioactivity stays in the reactor area.
• Light Water Cooled

4. Working Of PWR
In a typical design concept of a commercial PWR
the following process occurs:
1. The core inside the reactor vessel creates heat.
2. Pressurized water in the primary coolant loop
carries the heat to the steam generator.
3. Inside the steam generator, heat from the primary
coolant loop vaporizes the water in a secondary
loop, producing steam.
4. The steamline directs the steam to the main
turbine, causing it to turn the turbine generator,
which produces electricity.

5. Layout of PWR

6. Fuel Used
Enriched Uranium
• That is higher the amount of 92U235 in the
Fuel.
• The uranium oxides (UO2) is used instead
of pure uranium.
• UO2 is highly resistant to irradiation
damage and is well adopted to the high
burns-aps.
• It is also highly resistant to corrosion to
water.

7. Advantages
• Much fewer control rods are required in a PWR.
• Since the two circuits are independent of each other, it makes
it very easy for the maintenance staff to inspect the
components of the secondary circuit without having to shut
down the power plant entirely.
• A PWR has got a high power density and this, combined with
the fact that enriched Uranium is used as fuel instead of
normal Uranium, leads to the construction of very compact
core size for a given power output.
• the water used in the turbine side is free from radioactive
steam hence the piping on that side is not required to be clad
with special shielding materials.
• The water used which is used as coolant, moderator and
reflector is cheap in first cost and available in plenty

8. Disadvantages
• The primary circuit consists of high temperature, high
pressure water which accelerates corrosion. This means that
the vessel should be constructed of very strong material such
as stainless steel which adds to construction costs of PWR.
• PWR fuel charging requires the plant to be shut down and this
certainly requires a long time period of the order of at least a
couple of months.
• The pressure in the secondary circuit is relatively quite low as
compared to the primary circuit hence the thermodynamic
efficiency of PWR reactors is quite low of the order of 20.
• thermodynamic efficiency of the plant is very low(20%).
• Fuel suffers radiation damage and, therefore, its reprocessing
is difficulty.

9. Thanks