PROTOTYPE
FAST BREEDER REACTOR (PFBR) – SCI & TECH
News:
Is India finally entering
stage II of its nuclear programme? | Explained
What's
in the news?
●
Prime Minister Narendra Modi witnessed the
start of the process of core-loading the indigenous prototype fast breeder
reactor (PFBR) at the Madras Atomic Power Station in Kalpakkam, Tamil Nadu.
Key
takeaways:
●
A statement from his office called the
occasion “a historic milestone in
India’s nuclear power programme”.
Prototype
Fast Breeder Reactor:
●
It is a machine that produces more nuclear fuel than it consumes.
Fuel:
●
The Fast Breeder Reactor (FBR) will
initially use the Uranium-Plutonium
Mixed Oxide (MOX) fuel.
●
The Uranium-238
“blanket” surrounding the fuel core will undergo nuclear transmutation to
produce more fuel, thus earning the name ‘Breeder’.
Transmutation:
●
The use
of Thorium-232, which in itself is not a fissile material, as a blanket is
also envisaged in this stage.
●
By transmutation, Thorium will create
fissile Uranium-233 which will be used as fuel in the third stage.
Coolant:
●
It uses liquid sodium, a highly reactive substance, as coolant in two
circuits.
●
Coolant in the first circuit enters the
reactor and leaves with (heat) energy and radioactivity.
●
Via heat-exchangers, it transfers only the
heat to the coolant in a secondary circuit.
●
The latter transfers the heat to
generators to produce electricity.
Indigenously
built:
●
It has been fully designed and constructed
indigenously by Bhartiya Nabhikiya
Vidyut Nigam Ltd (BHAVINI) with significant contribution from more than 200
Indian industries including MSMEs.
Safety:
●
In terms of safety, the PFBR is an
advanced third generation reactor with inherent passive safety features
ensuring a prompt and safe shut down of the plant in the event of an emergency.
Significance:
●
Since it uses the spent fuel from the
first stage, FBR also offers great advantage in terms of significant reduction
in nuclear waste generated, thereby avoiding the need for large geological
disposal facilities.
●
Once commissioned, India will only be the
second country after Russia to have a commercial operating Fast Breeder
Reactor.
●
FBR is thus a stepping stone for the third
stage of the program paving the way for the eventual full utilization of
India’s abundant thorium reserves.
India’s
3-Stage Nuclear Programme:
●
India's three-stage nuclear power
programme was formulated by Dr Homi
Bhabha to secure the country's long term energy independence.
●
The ultimate focus of the programme is on
enabling the thorium reserves of India to be utilised in meeting the country's
energy requirements.
●
Thorium is particularly attractive for
India, as India has only around 1–2% of the global uranium reserves, but one of
the largest shares of global thorium reserves at about 25% of the world's known
thorium reserves.
○
Thorium is found in the monazite sands of
coastal regions of South India.
●
Dr Homi Bhabha, therefore, devised a
three-stage nuclear power programme to make the most of India's limited uranium
reserves and abundant thorium reserves.
●
Each stage of the programme has fuel cycle
linkages.
○
This means that spent fuel from one stage
is reprocessed to obtain fuel for the next stage — there is little to no
wastage.
●
Ultimately, the goal is to generate
nuclear power while ensuring long-term energy security.
3-Stages
of India’s Nuclear Programme:
|
Pressurised heavy water reactors (PHWRs) |
Fast Breeder Reactor (FBR) |
Thorium Based Reactor |
|
Pressurised heavy water reactors (PHWRs) using natural uranium as
fuel:
The first stage involves using natural uranium in PHWRs to
multiply domestically available fissile resources.
Natural uranium consists of 0.7 per cent Uranium-235, which
undergoes fission to release energy.
The remaining 99.3 percent is Uranium-238, which is not fissile
but can be converted into the fissile element Plutonium-239 in a nuclear
reactor.
|
FBRs using plutonium as fuel: In the second stage, plutonium from the spent fuel of PHWRs is
used in FBRs, such as the one at Kalpakkam which saw the initiation of core
loading on 4 March.
FBRs are fuelled by a mixed oxide of Uranium-238 and
Plutonium-239, which is recovered by reprocessing the spent fuel from the
first stage.
In FBRs, Plutonium-239 undergoes fission, producing energy and
more Plutonium-239 through the transmutation of Uranium-238. This process allows FBRs to produce energy and additional fuel,
which is why they are termed "breeders." FBRs generate more fuel
than they consume.
Over time, a stockpile of plutonium can be built up by
introducing Uranium-238 into the reactor. |
Advanced reactors using Uranium-233 as fuel in a thorium-uranium
cycle:
Once enough nuclear capacity is built, the third stage will
involve using thorium, which will be converted into Uranium-233 in FBRs.
Thorium-232, which is abundant in India, is not fissile.
Therefore, it needs to be converted into a fissile material, Uranium-233,
through transmutation in an FBR.
Significant commercial use of thorium can only begin when there
are abundant supplies of either Uranium-233 or plutonium.
The conversion from thorium to uranium is planned to be achieved
in the second stage of the programme, which involves the commercial operation
of FBRs. |