SIR SHAHID KHALIL
SAMEED QADRI ( 11-ME-69)
M.ALI KIANI (11-ME-198)
Nuclear reactors are devices in which fissionable
elements such as uranium, thorium, or plutonium
are made to undergo a nuclear chain reaction.
Neutrons are bombarded to Uranium nuclei. It
disintegrates into two smaller atoms ( Ba &
Kr), releasing neutrons and binding energy . One
of the neutron hits another Uranium-235
atom, thus furthur releasing neutrons and binding
energy. Thus , process continous if it is not
controlled. This is called chain reaction.
Fuel rods ( Packets of Uranium oxide
arranged in tubes to form rods )
Magnox is short for Magnesium non-oxidising
It is basically an alloy mainly of magnesium with small amounts of aluminium
and other metals
It is used to clad the fuel rods inside the reactor.
This material has the advantage of a low
neutron capture cross-section, but has two major
It limits the maximum temperature, and hence the thermal efficiency, of the plant.
It reacts with water, preventing long-term storage of spent fuel under water.
Magnox is an old type of nuclear power reactor
which was designed in the United
Kingdom, and was exported to other
countries, both as a power plant ( as a power
reactor ) and producer for plutonium ( as a
research reactor )
Wylfa Nuclear Generating Facility contains the
world's last operating Magnox reactor
These are graphite moderated reactors and use
natural uranium as fuel & MAGNOX as fuel
Working pressure varies from 6.9 to 19.35 bar
The first Magnox reactors at Calder Hallwere
designed principally to produce plutonium for
The production of plutonium from uranium
generates a large amount of heat also , which could
be used in a turbine to generate electricity.
Nuclear power generation is 25 % expensive than
electricity from coal, yet economical due to
production of plutonium.
There are two nuclear fuel reprocessing plants at
Advanced Gas-cooled Reactors (AGR)
Light Water Reactors (LWR)
This all happens in the Fuel Handling Plant. The fuel is
then transferred to the Magnox Reprocessing Plant.
In early operation it was found that there was
significant oxidation of mild steel components by
the high temperature carbon dioxide
coolant, requiring a reduction in operating
temperature and power output.
For example the Latina reactor was derated in 1969
by 24%, from 210 MWe to 160 MWe, by the
reduction of operating temperature from 390 to 360
Magnox plants literally means magnox nuclear
A small 5 MW experimental reactor at
Yongbyon, operated from 1986 to 1994, and
restarted in 2003. Plutonium from this reactor's
spent fuel has been used in the North Korea nuclear
A 200 MW reactor at taechon, construction of
which also halted in 1994.
This is the general term for all type of carbon
reactors, including the Magnox.
The Magnox was replaced in the British power
station program by the Advanced gas-cooled reactor
A key feature of the AGR was the replacement of
magnox cladding to allow higher temperatures and
greater thermal efficiency.
The Magnox reactors were considered at the time to
have a considerable degree of inherent safety
because of their simple design, low power
density, and gas coolant.
Failure of the reactor shutdown system to rapidly
shut down the reactor, or failure of natural
circulation, was not considered in the design.