NUCLEAR WASTE AND REMEDIATION STRATEGY Course Seminar CE 641 - - PowerPoint PPT Presentation
NUCLEAR WASTE AND REMEDIATION STRATEGY Course Seminar CE 641 Presented by Aniruddh Jain Roll No: 09304018 M.Tech 1st Year WHAT IS NUCLEAR ENERGY Nuclear energy is the energy released by the splitting (fission) or merging together (fusion)
Course Seminar CE 641 Presented by
Aniruddh Jain Roll No: 09304018 M.Tech 1st Year
WHAT IS NUCLEAR ENERGY ΔE = Δm.c²
In which ΔE = energy release Δm = mass defect c = the speed of light in a vacuum
Nuclear Fusion Nuclear Fission
NUCLEAR ENERGY FACTS AND FIGURES
On the morning of 6th August,1945 HIROSHIMA
am local time
were either damaged or completely destroyed.
literally seared to death," the Japanese radio broadcaster reported.
whose surface temperature reached about 8000 degree centigrade
It contained 64 kg of uranium, of which 0.7 kg underwent nuclear fission, and
transformed into energy. That is with a efficiency of only 1.5 %
Hiroshima before and after
NUCLEAR ENERGY FACTS AND FIGURES Continued…….
“Fat Man” was dropped on the city of Nagasaki
Some energy equivalents
produce about 20 trillion joules of energy (2 × 1013 joules); as much energy as 1500 tonnes of coal. URANIUM AVAILIBILITY
mercury ,and it is about as abundant as arsenic
NAGASAKI BEFORE & AFTER
HENCE THE RACE OF POWER AND ENERGY HAS LEAD TO THE DEVELOPEMET OF NUCLEAR ENERGY AND ALONG WITH IT HAS LEAD TO THE GENERATION OF HIGHLY HAZARDOUS NUCLEAR WASTE WHICH HAS POSED A BIG QUESTION OF
IN FRONT OF THE DEVELOPED WORLD
Exempt waste and very low level waste
produced during dismantling operations on nuclear industrial sites.
Low level waste
Contains small amounts of mostly short-lived radio activity
Intermediate level waste
from reactor decommissioning
High level waste
reactor core
1000 MW light water reactor
For the same capacity plant
which are usually 7 meter deep to allow 3 meter of water over to fully shield it
with air circulation and the fuel is surrounded by concrete which eventually after 40-50 year has one thousand
handling easy and finally disposing it permanently
generation to get something out of it.
borosilicate glass and eventually disposed deep underground
Converting Radioactive waste materials to suitable forms for subsequent management, such as transportation, storage and final disposal Incineration
and then is incinerated at 1000º
Bituminization
public concern Compaction Volume Reduction technology where that is used mainly for LLW volume reduction Volume reduced upto a factor 5
Cementation
added with grout and then allowed to set.
and disposal.
Vitrification
which is stable and insoluble.
activity in contaminated ground as well as creating a barrier to prevent further spread of contamination
Near-surface disposal at ground level, or in caverns below ground level (at depths of tens of meters)
short half-life( upto about 30 years)
Deep geological disposal
provided by a combination of engineered & natural barriers (rock, salt, clay)
mined tunnels or tunnels or caverns into which packaged waste would be placed
containers are surrounded by bentonite or cement to provide another barrier
Methods, Proposed sites & Case Histories Disposal in strong fractured rocks The Swedish proposed disposal concept uses a copper container with a Steel insert to contain the spent fuel. After placement in the repository About 500 m deep in the bedrock the container would be surrounded by a Bentonite clay buffer. Disposal in clay The Belgian disposal concept proposes that spent fuel and HLW is placed in high integrity steel containers and then emplaced in excavated tunnels within a ductile clay. Yucca Mountain Located in the remote Nevada desert, is the proposed site for the Construction of A US national repository to store spent fuel and high-level waste from nuclear power and military defense
unsaturated layer of volcanic tuff rock. Containment relies on extremely low water table which lies 300m below the repository.
Yucca Mountain
Methods & Proposed sites & Case Histories Continued…. Disposal in layered salt strata The Waste Isolation Pilot Plant in New mexico for defence transuranic Waste has been operational since 1999. For this repository natural rock salt is excavated from a several meters thick layer, sandwiched between
excavations contain large volumes of long-lived ILW. A feature of salt Environments is the very low rate of groundwater flow and the gradual Self-sealing of the excavations due to creep
Long-term above ground storage
anywhere Disposal in outer space
to cost and potential risks of launch failure Deep boreholes Deep bore holes drilled from the surface to depths of several kilometers
sealed with material such as bentonite , asphalt and concrete. Rock Melting The HLW could be placed in a deep borehole. The heat of the waste can Melt the surrounding rock which on cooling will encase the waste & thus the Waste is distributed throughout the large volume of rock.
Deep Bore Hole Disposal
Containers release enough heat to create a melt zone around the borehole. As the waste decays and cools, the melt zone resolidifies around the containers, entombing the waste forever.
Disposal at subduction zone Where one denser section of the Earth’s crust moving towards and Underneath another lighter section. This is marked by an offshore
trench region Such that they would be drawn deep into the Earth. OTHER IDEAS FOR DISPOSAL AND WHAT CAN BE THE FUTURE TRENDS
Disposal at sea Has been tried in certain countries but this method is not permitted by a number of international agreements. Sub seabed disposal It is been investigated by many countries but not yet implemented. Disposal in ice sheets For this option containers of heat-generating waste would be placed in stable ice sheets such as those found in Greenland and Antarctica. The containers would melt the surrounding ice and be drawn deep into the ice sheet, where the ice would refreeze above the wastes creating a thick barrier. Direct injection Tried in USA and Russia but is not very popular
Bioremediation
Some organisms, such as the lichen Trapelia involuta or microorganisms such as the bacterium Citrobacter, can absorb concentrations of uranium that are up to 300 times higher than in their environment.After one day, one gram of bacteria can encrust themselves with nine grams of uranyl phosphate crystals; this creates the possibility that these
bioremediation to decontaminate uranium- polluted water. Ref: Wikipidia
COLUMBUS, Ohio, March 17, 2009 (ENS) - An
international team of scientists has found a common soil bacterium that might one day be used to clean up radioactive toxics left from nuclear weapons production decades ago. Ref: Environment News Service (ENS) 2009 The strain Bacillus sphaericus has evolved a crystalline surface layer (S-layer) that covers the
protective barrier to the bacteria, it serves to accumulate high amounts of toxic metals such as uranium, lead, copper, aluminum, and cadmium. Bacteria may be the template for new technology aimed at nuclear waste removal. The time may be near when synthetic S-layer discs can be placed in contaminated areas and act as sponges, cleaning up a big toxic mess Ref: Biotechnology Advances. 2005.
NUCLEAR ENERGY IS THE NEED OF FUTURE AND IT WOULD BE FOOLISHNESS ON OUR PART TO HAMPER ITS DEVELOPMENT AND SO IT BECOMES ARE PRIME DUTY TO FIND OUT BETTER WAYS FOR NUCLEAR WASTE MANAGEMENT SO THAT WE CAN BUILD A BETTER FUTURE IN A CLEAN ENVIRONMENT.
practices in India, Nuclear Engineering and Design Volume 236, Issues 7-8, April, Pages 914-930
Radioactive Waste, United States Environmental Protection Agency (EPA), EPA/625/R-92/002 (May 1992) available from the EPA's National Service Center for Environmental Publications
ENERGY AGENCY, VIENNA, 1994