radioactive wastes

7/27/2019 Radioactive Wastes

1/23

RADIOACTIVE WASTES

SUBMITTED BY,SHINOJ K. THATTIL

ROLL NO 63

S4 EEE

JECC


2/23

CONTENTS

INTRODUCTION

TYPES OF NUCLEAR WASTES

SOURCE

MANAGEMENT OF NUCLEAR WASTE

NUCLEAR HAZARDS CONCLUSION

REFERENCE


3/23

INTRODUCTION

Radioactive wastes are waste typescontaining radioactive chemical elements thatdo not have a practical purpose.

Radioactive waste typically comprises anumber ofradioisotopes: unstableconfigurations of elements that decay,emitting ionizing radiation which can beharmful to human health and to theenvironment.

Those isotopes emit different types andlevels of radiation, which last for differentperiods of time.


4/23

SOURCE

Radioactive waste comes from a number ofsources.

The majority originates from the nuclear fuelcycle and nuclear weapon reprocessing.

Other sources include medical and industrialwastes, as well as naturally occurring radioactive

materials (NORM) that can be concentrated as aresult of the processing or consumption of coal,oil and gas, and some minerals.


5/23

TYPES OF NUCLEAR

WASTES

LOW LEVEL WASTE (LLW)

INTERMEDIATE LEVEL WASTE (ILW) HIGH LEVEL WASTE (HLW)

TRANSURANIC WASTE (TRUW)


6/23

LOW LEVEL WASTE (LLW)

Low level waste (LLW) is generated from hospitals andindustry, as well as the nuclear fuel cycle.

It comprises paper, rags, tools, clothing, filters, etc.,

which contain small amounts of mostly short-livedradioactivity.

Commonly, LLW is designated as such as aprecautionary measure if it originated from any region ofan 'Active Area', which frequently includes offices withonly a remote possibility of being contaminated withradioactive materials.

Low level waste is divided into four classes, class A, B,C and GTCC, which means "Greater Than Class C".


7/23


8/23


9/23

HIGH LEVEL WASTE (HLW)

High level waste (HLW) is produced by nuclearreactors.

It contains fission products and transuranic elementsgenerated in the reactor core.

It is highly radioactive and often thermally hot.

LLW and ILW accounts for over 95% of the totalradioactivity produced in the process of nuclearelectricity generation.

The amount of HLW worldwide is currentlyincreasing by about 12,000 metric tons every year,which is equal to about 100 double-decker busses.
http://en.wikipedia.org/wiki/Image:Nuclear_waste_flask_train_at_Bristol_Temple_Meads_02.jpg


10/23

High Level Waste flasks are transported by train in the United Kingdom.

Each flask is constructed of 3 ft (0.91 m) thick solid steel and weighs in

excess of 50 tons
http://en.wikipedia.org/wiki/Image:Nuclear_waste_flask_train_at_Bristol_Temple_Meads_02.jpg


11/23

TRANSURANIC WASTE (TRUW)

Elements that have an atomic number greater thanuranium are called transuranic ("beyond uranium").

Because of their long half-lives, TRUW is disposed more

cautiously than either low level or intermediate levelwaste.

In the U.S. it arises mainly from weapons production,and consists of clothing, tools, rags, residues, debris andother items contaminated with small amounts ofradioactive elements (mainly plutonium).


12/23

MANAGEMENT OF NUCLEAR

WASTE STORAGE

GEOLOGICAL DISPOSAL TRANSMUTATION

REUSE OF WASTE

SPACE DISPOSAL


13/23

STORAGE

High-level radioactive waste is stored temporarily inspent fuel pools and in dry cask storage facilities.

This allows the shorter-lived isotopes to decaybefore further handling.

In 1997, in the 20 countries which account for mostof the world's nuclear power generation, spent fuelstorage capacity at the reactors was 148,000

tonnes, with 59% of this utilized. A number of nuclear power plants in countries that

do not reprocess had nearly filled their spent fuelpools, and resorted to Away-from-reactor storage

(AFRS).


14/23

GEOLOGICAL DISPOSAL

Storing high level nuclear waste above ground for acentury or so is considered appropriate by manyscientists. This allows for the material to be more easily

observed and any problems detected and managed,while the decay over this time period significantlyreduces the level of radioactivity and the associatedharmful effects to the container material.

Sea-based options for disposal of radioactive waste

include burial beneath a stable abyssal plain, burial in asubduction zone that would slowly carry the wastedownward into the Earth's mantle, and burial beneath aremote natural or human-made island.


15/23

REUSE OF WASTE

Another option is to find applications of the

isotopes in nuclear waste so as to reuse them.

Already, caesium-137, strontium-90 and a fewother isotopes are extracted for certain industrial

applications such as food irradiation and

radioisotope thermoelectric generators.

While re-use does not eliminate the need to

manage radioisotopes, it may reduce the

quantity of waste produced.


16/23

SPACE DISPOSAL

Space disposal is an attractive notion because it

permanently removes nuclear waste from the

environment. It has significant disadvantages, not least of

which is the potential for catastrophic failure of a

launch vehicle.

To further complicate matters, international

agreements on the regulation of such a program

would need to be established


17/23

NUCLEAR HAZARDS

A number of incidents have occurred when radioactivematerial was disposed of improperly, shielding duringtransport was defective, or when it was simply

abandoned or even stolen from a waste store. In the former Soviet Union, waste stored in Lake

Karachay was blown over the area during a dust stormafter the lake had partly dried out.

In other cases lakes or ponds with radioactive wasteaccidentally overflowed into the rivers during exceptionalstorms.
http://en.wikipedia.org/wiki/Image:Chernobyl_Disaster.jpg


18/23

Chernobyl reactor number four after the disaster, showing the

extensive damage to the main reactor hall (image center) and

turbine building (image lower left)
http://en.wikipedia.org/wiki/Image:Chernobyl_Disaster.jpg


19/23

HIROSHIMA NUCLEAR BOMB BLAST


20/23

NAGASAKI NUCLEAR BOMB BLAST


21/23

CONCLUSION

Although nuclear reactions and reactors

are very useful and reliable sources of

energy it has many drawbacks. It can also endanger the life of human

being.

Proper use of nuclear energy has a mainrole in development.


22/23

REFERENCE

en.wikipedia.org/wiki/Nuclear_hazard

www.ccsa.asn.au/nic/NucHazards/NucHaz

.html

www.trinity.wa.edu.au/plduffyrc/issues/nuc

lear.htm


23/23

radioactive wastes

Documents