A Broad PPT on Nuclear Waste Management and Present storage Options used by Governments around the world. Recycling methods also Mentioned

1. NUCLEAR REACTORS
And waste management
BY
Nithin sai
Manjunath
Chaitanya
Arpan Bhatt
Kaushik kumar

3. •A Nuclear Reactor uses this energy to
convert water into steam and the steam
is used to drive a generator.
•In order to start a reactor a slow
neutron is introduced into the chamber.
Which will start the chain reactor or
domino effect.
•There are many types of reactor
•Thermal-Neutron, Molten salt, Molten
metal, Thorium,etc..,

4. •The reactor efficiency is based on
carnot principle.
•The hotter ore the reactor the more
efficient it is.

5. •A thermal-neutron reactor is
a nuclear reactor that uses slow
or thermal neutrons. Uranium-
235 only reacts with slow
neutrons. When it splits into two
lighter nuclear it releases three
fast neutrons. In order two
sustain a chain reaction the fast
neutrons have to be slowed down
using moderater(H2O in this
case).

7. •These reactors only utilizes only 1% of the atom ability.
•99% of waste is stored in facilities for long term decay process.

8. •Waste produced by hospitals
and other radioactive
applications are classified into
EW and VSLW and can be
easily dumped.
•Decommissioned Nuclear
facilities and equipments
comes under VLLW.
•Indirect or Direct surfaces of
nuclear reactor based on
contact radiation dose and
radionuclide comes under
LLW and ILW.(2mSv/h).
•Nuclear waste or Left over
non-fissile material is known
as HLW.

10. • When the operator decides that the Core energy is completely deprived the fuel rods
are pulled out from the reactor and submerged in water pool.
•The core may lost its ability to be Fissile but it is still highly radioactive. The products it
contains mainly are Plutonium, Americium , Neptunium etc.., these are also called as
TRANSURANIC ACTINIDES.

11. •During this phase the left over core
is constantly cooled.
•In some countries the waste is
transferred to Dry casks as shown in
the figure.
•These dry casks are stored in
mountains where they can’t be
disturbed by earthquakes are
humans.
•But why Thermal-neutron Reactor
is still used popularly used even
though they produces more waste
because they are CHEAP.

13. VITRIFICATION
•The process in which radioactive
elements are mixed with sugar and create
a plasma and then be converted into
glass.
•This is highly radioactive but can be
handled easily.
•This is an expensive process which
some countries prefer.
•At present new methods like using Slag
from metal extraction can replace sugar
and made this process cheap.

14. •In-situ vitrification uses electrodes to heat up the
material.
•Modular In-container Vitrification uses
independently controlled coils which will heat the
core.

16. •This is the result of vitrification
process.
•Stable crystals producing less
radioactivity can easily be stored
in container site.

17. LONG TERM STORAGE
•This is YUCCA mountain
america’s nuclear repositary
site.
•All the nuclear waste from US
is stored here for Decay process.
•This mountain provides
shielding from earthquakes or
any other natural disaster.

18. FINLAND LONG- TERM STORAGE
•Finland completed world’s
largest underground repositary
below 450m from ground
level. It is now considered
safest place on earth to store
nuclear waste.
•It’s is present in onkalo near
Eurajoki, Finland.

19. FOURTH GENERATION FAST BREEDER REACTORS
•One way to decrease the is to
burn the waste in fast-breeders
•Fast breeders uses fast neutrons
for fission. This means U-238 can
burn in the process.
•This will decrease the significant
amount of waste.
•The waste products of Fast
Breeder are Fission products.
Much more smaller than
Actinides.
•They can decay probably in a
decade.

20. •This fourth generation
reactors can efficiently
power a Aircraft carrier
more than 25 years.

21. •The reactor produces
weapon grade plutonium and
radioactive Cesium.
•Fast breeder doesn’t need
any moderator.
•There are many types of
reactor like Gas cooled,
Sodium cooled, Metal cooled
reactors.

22. •This is a schematic of typical
gas-cooled reactor.
•In gas cooled reactors the
core material can be made of
ceramic materials and usable
at high temperatures.
•Helium gas cooled are the
most efficient because it is
inert and stay in one phase at
any condition.
•Gas can easily be controlled
using emergency valves in
cause of accidents.

25. THORIUM KEY TO THE FUTURE

26. THORIUM REACTORS
•THORIUM is not fissile in nature
but upon absorption of a neutron it
will decays into protactinium and
Uraninum-233.
•U-233 is nicely fissile due to its
better neutron economy.
•Uranium-233 can produce an
average of 2 neurons per split. This
neutrons can be caputured by
Thorium and will gernarate more
Uranium-233.

28. •In INDIA AP and Telangana
combined has highest Thorium
reserves.
•This can power India more than
100 years.

29. SMALL MODULAR REACTORS(SMR)
FUTURE OF NUCLEAR INDUSTRY

30. •As the name says modular
reactor can be made outside in
a factory and can be
transported to site.
•They usually have 100-200
MW range

31. GT-MHR(GAS TURBINE MODULAR HELIUM REACTOR)
•Gas turbine modular heilum reactor
uses TRISO as fuel.
•The core is made of carbonaceous
matrix and core is arranged according
the configuration of reflector.
•The core is heated so much that
hydrogen is directly produced which
can be used in commercial services.
•From this weapons grade plutonium
can be used as fuel and de commisned
weapons can be used.
•This reactor can transmutate the
LWR spent fuel.

34. •Russia unveiled the world’s first floating nuclear power plant (FNPP), named Academic
Lomonosov. This equipped with two modular reactors. At present this ship is in the dock
of Chaun-Bilibino, Pevek.
•Providing power to remote areas where power transition is not possible.

35. PEBBLES REPLACING PELLETS

39. •In this Triso configuration a
zirconium carbide layer is added
and a Pyrocarbon seal coat
supporting it.
•Triso particle will in the size of
0.92mm in this uranium kernal
will be only o.5mm size.

40. DIAMOND BATTERY
•Diamond Battery is made up of
Graphite waste from nuclear
reactor.
•This concept is proposed by
university of Bristol in their lecture
on 25 November 2016.
•Diamond battery is a Betavoltaic
cell which generates electric current
from beta particles of radioactive
waste.
•Using carbon-14 in the form
of diamond-like carbon as the beta
radiation source, and additional
normal-carbon DLC to make the
necessary semiconductor
junction and encapsulate the
carbon-14.

41. PROTOTYPES
•University of Bristol
prototype
Moscow Institute of Physics
and Technology prototype
•No known prototype uses 14C
as its source, there are
however some prototypes that
use nickel-63 as their source
with diamond semiconductors
for energy conversion which
are seen as a stepping stone to
a possible 14C diamond
battery prototype.

42. RAW MATERIAL: C-14 (carbon 14
isotope)
This raw material is generally a waste
which is produced after controlled
nuclear reaction in graphite moderate
reactors.
In the graphite rods used as moderators,
some of the non-radioactive carbon-
12 and carbon-13 isotopes in graphite
get converted into radioactive 14C
by capturing neutrons.
Once the graphite blocks are removed
during decommissioning, their induced
radioactivity qualifies them as low-level
waste requiring safe disposal.

43. Manufacturing

44. 1.Collection of radioactive moderator blocks
(graphite moderators):
• After the moderator blocks are used, they are a nuclear waste which
are collected for disposal.

45. 2.Sublimation:
• These collected blocks of graphite are then sublimated by heating
them to a temperature of 3914 K (sublimation point). The
radioactive graphite is thus turned into gaseous carbon.

46. Disposal of remaining blocks:
• after sublimation the blocks turn less radioactive and possibly easy
to dispose.

47. 4.Making the diamonds:
• the produced C14(gaseous) is thus collected and used to
manufacture artificial diamonds using a process named, chemical
vapor deposition using low pressure and elevated temperature,
noting that this diamond would be a thin sheet and not of the
stereotypical diamond cut.

48. 5.Sandwiching:
• the formed diamonds will still be producing beta radiations.
Researchers also claim this diamond would be sandwiched between
non-radioactive man-made diamonds made from 12C which would
block radiation from the source and would also be used for energy
conversion as a diamond semiconductor instead of
conventional silicon semiconductors.

49. Result-
• The radioactive diamonds sandwiched with C12 diamond would
produce electricity. Though the energy density of these batteries is
not consistent, but these batteries are capable of producing charge
for about 28,000years.

50. • What makes this idea good:
• These diamonds would solve the problem of disposal of
the nuclear waste. Which is a serious threat to the
environment.
• They make the moderators less radioactive and easy to
dispose.
• The diamonds are also capable of providing electrical
energy.
• They would provide energy for thousands of years
without harming the environment.