Disposal Options for Radioactive Waste (K.M. Ghazali)

7/28/2019 Disposal Options for Radioactive Waste (K.M. Ghazali)

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DISPOSAL OPTIONS

FORRADIOACTIVE WASTE

By

K. M. GHAZALI

WASTE MANAGEMENT DIVISIONDIRECTORATE GENERAL OF NATIONAL REPOSITORY

PAKISTAN ATOMIC ENERGY COMMISSION


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RADIOACTIVE WASTE

Radioactive waste is of peculiar nature

Contains or is contaminated with

radionuclides at concentrations oractivities greater than clearance levels as

established by the regulatory body

Radionuclide emits alpha, beta andgamma radiations of various energies


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The *half lives of these radionuclides

range from few hours to millions of years*Time period in which half the initial

number of atoms of radioactive element

disintegrate in to atoms of the element

into which they change directly

Several thousand years are required for

the activity of the radionuclides to decayto the level which is not hazards to the

man and his environment


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Radioactive Materials

Radioactive Waste

Medicine Research Agriculture Industry

Nuclear Others

U-Mining

& Milling

U-

Processing

Fuel

FabricationReprocessing

Production

Reactor
http://localhost/var/www/apps/conversion/tmp/scratch_10/NEW%20FOLDER/SPD%20July%202006/HYPER/waste%20&%20comparison.PPThttp://localhost/var/www/apps/conversion/tmp/scratch_10/NEW%20FOLDER/SPD%20July%202006/HYPER/waste%20&%20comparison.PPT


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RADIATION EFFECTS

ON HUMANSRadiation occurs when unstablenuclei of atoms decay and release

particles. There are many differenttypes of radiation

When these particles touch various

organic material such as tissue,damage may, and probably will, bedone. Radiation can cause burns,

cancers, and death
http://library.thinkquest.org/3471/radiation_types.htmlhttp://library.thinkquest.org/3471/radiation_types.html


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WHAT IS DISPOSALDisposal means emplacement of

radioactive waste in a repository with

reasonable assurance for safety,without the intention of retrieval and

without reliance on long term

surveillance and maintenance


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The safe disposal of radioactive waste

is recognized worldwide as an integralpart of nuclear power programmes

A huge quantity of nuclear waste

comprising spent fuel elements,

activated resins, activated parts of the

plant will put a question to the

competent authorities for their

immediate ultimate disposal

Cont...


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From 19401970, most low-level

wastes were placed into steel drumsand dumped into the ocean or into

pits on land

Since 1970, the United States has

been disposing its low-level waste at

government regulated disposal sites

Cont...
http://science.jrank.org/pages/6488/Steel.htmlhttp://science.jrank.org/pages/4828/Ocean.htmlhttp://science.jrank.org/pages/4828/Ocean.htmlhttp://science.jrank.org/pages/6488/Steel.html


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WASTE DISPOSAL OBJECTIVES

The main objective is to isolate

radioactive waste from the biosphere for

a long period of time to avoid any

possible subsequent release of

radionuclide in the environment


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The another objective of thedisposal of the radioactive waste in a

manner that protect human health and

environment now and in the future

with out imposing undue burdens on

future generation

Cont...


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To achieve these objectives it is

needed to concentrate and contain thewaste and to isolate it from the

biosphere.

The biosphere is inhabited by living

organism includes those elements

accessible to humans or used byhumans (groundwater, surface water

and marine resources)

Cont...


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PATHS OF RADIATION TO THE BODY


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DISPOSAL OPTIONS

The biggest technological challengepresently facing the nuclear industry

and society is the long-term, safe

disposal of high-level radioactive waste

The disposal of radioactive waste

which is the final step in themanagement chain is of a vital

importance


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DISPOSAL OPTIONS

DISPOSAL INTO OCEAN

SEA DUMPING

SEA-BED DISPOSAL

DISPOSAL IN GLACIATED AREAS

REMOTE ISLAND DISPOSAL

DISPOSAL INTO SPACE


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GROUND DISPOSALABOVE GROUND STORAGE

NEAR SURFACE DISPOSAL

DEEP UNDERGROUND DISPOSAL

Cont...


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DISPOSAL INTO OCEAN

Scientists have considered different

options for the disposal of nuclear

waste into the ocean floor because deepwithin the ocean, the radiation from the

waste would not harm people or the

environment


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DISPOSAL INTO OCEAN

In the late 1940s, the nuclear

industry had chosen the oceans as a

convenient place to dispose of its

inconvenient wastes

Sea dumping and sea-bed disposal

options could be convenient


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DISPOSAL INTO OCEAN

DISADVANTAGE

This option includes the difficulty of

recovering the waste, if necessary, once

it is emplaced deep in the ocean

Establishing an effective international

structure to develop, regulate, andmonitor a seabed repository would be

extremely difficult


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SEA DUMPING

According to experts, a depth of

3,000 meters is required to insure a

high degree of safetyOtherwise, anything dumped in

shallower waters could easily be taken

up by living organisms quickly


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Cont..

Dumping of highly radioactivewastes at sea has been banned

worldwide for more than three decades

Russia has been dumping highly

radioactive materials in the Barents

Kara Seas since the late 1950s


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Cont..

Today scientists are trying to assesswhat possible damage the dumping

might have done to the fragile

environment of Sea

Unfortunately, many of the

confirmed Russian dumping sites are

not at that depth


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Cont..

The USA, the then USSR, France, the

United Kingdom, Germany, Sweden and

other states used the sea as a

radioactive dump, both in the Pacific and

the Atlantic

The Oslo Convention was the first

regional treaty to regulate the dumping

of wastes at sea - it was negotiated in1972 by the countries bordering the

North-East Atlantic


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Cont..

A few months later in 1972 thenegotiations on the London Dumping

Convention were concluded

This time the negotiations were less

dominated by the Western European

nuclear states, and, as a result, the

dumping of so-called high-level

radioactive wastes was banned


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SEA DUMPING

DISADVANTAGE

Dumping at sea is a safety risk

to people and to the natural

biology of waters


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SEA-BED DISPOSAL

The concept of disposal of high level

radioactive waste by burial in suitable

geological media beneath the deepocean floor is a potential alternative to

geological disposal on land


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SEA-BED DISPOSAL


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Cont..

Sea-bed disposal is different from sea

dumping

In the Sea-bed concept a multi-barrier

system would be involved, including a

suitable waste form such as glass and

the use of corrosion resistant packages


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Cont..

Deep sea-bed sediment formations

would be chosen in order to contain

radionuclides after the waste package

fails through corrosion and radionuclides

are released from the waste

Such sediments would be made up of

very fine-grained particles with theability to absorb and impede the

movement of most waste radionuclides


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SEA-BED DISPOSAL

DISADVANTAGE

A significant difference is that this

disposal would be ideally suited for the

establishment of international

cooperative activities, although usingthe high sea, which is common property,

represents a major political complication


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DISPOSAL IN

GLACIATED AREASScientists have considered placing

waste containers on the surface or in ashallow hole where the heat from the

waste would cause them to slowly melt

to the bottom of the ice of Antarctica orGreenland


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POLAR ICE OF ANTARCTICA

THOUSANDS METER THICK


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DISPOSAL IN

GLACIATED AREASADVANTAGE

lack of population in Polar Regions and the

stability and thickness of polar ice

DISADVANTAGE

Disposal in glaciated areas, in Antarctica forexample, would require substantial changes to

international legal and political agreements


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DISPOSAL INTO SPACE

Leaving radioactive wastes on earth

creates permanent and tempting targets

for terrorism as well as threatening theenvironment

Space disposal is an attractive option

because it permanently removes nuclear

waste from the environmen


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Cont..

The National Aeronautics and Space

Administration (NASA) has researched

several methods of disposal in spacePossibilities included launching waste

containers into orbit around the sun


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Cont..

A ground-based laser system will

launch capsules directly out of the solar

system

The laser system will place thecapsules into a nuclear-safe orbit, at

least 1,100 kilometers above the earth,

so that they could not reenter for several

thousand years at a minimum


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Cont..

Another form of safe removal would

possibly be the space elevator. Encasing

the waste in glassified form inside a

steel shell 9 inches (230 mm) thick,which in turn is tiled with shuttle tile to

its exterior. If the launch vehicle fails

just before reaching orbit, the waste ballwill safely re-enter the earth's

atmosphere
http://en.wikipedia.org/wiki/Space_elevatorhttp://en.wikipedia.org/wiki/Space_elevatorhttp://en.wikipedia.org/wiki/Space_elevatorhttp://en.wikipedia.org/wiki/Space_elevator


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Cont..

A space elevator is a proposed mega

structure designed to transport material froma celestial body's surface into space as a way

ofnon-rocket space launch

A space elevator would consist of a cableanchored to the Earth's surface, reaching into

space. By attaching a counterweight at the

end, inertia ensures that the cable remainsstretched tight, countering the gravitational

pull on the lower sections, thus allowing the

elevator to remain in geostationary orbit
http://en.wikipedia.org/wiki/Megastructurehttp://en.wikipedia.org/wiki/Megastructurehttp://en.wikipedia.org/wiki/Materialhttp://en.wikipedia.org/wiki/Astronomical_objecthttp://en.wikipedia.org/wiki/Surfacehttp://en.wikipedia.org/wiki/Outer_spacehttp://en.wikipedia.org/wiki/Non-rocket_spacelaunchhttp://en.wikipedia.org/wiki/Earthhttp://en.wikipedia.org/wiki/Outer_spacehttp://en.wikipedia.org/wiki/Geostationaryhttp://en.wikipedia.org/wiki/Geostationaryhttp://en.wikipedia.org/wiki/Outer_spacehttp://en.wikipedia.org/wiki/Earthhttp://en.wikipedia.org/wiki/Non-rocket_spacelaunchhttp://en.wikipedia.org/wiki/Non-rocket_spacelaunchhttp://en.wikipedia.org/wiki/Non-rocket_spacelaunchhttp://en.wikipedia.org/wiki/Non-rocket_spacelaunchhttp://en.wikipedia.org/wiki/Non-rocket_spacelaunchhttp://en.wikipedia.org/wiki/Non-rocket_spacelaunchhttp://en.wikipedia.org/wiki/Non-rocket_spacelaunchhttp://en.wikipedia.org/wiki/Outer_spacehttp://en.wikipedia.org/wiki/Surfacehttp://en.wikipedia.org/wiki/Astronomical_objecthttp://en.wikipedia.org/wiki/Astronomical_objecthttp://en.wikipedia.org/wiki/Astronomical_objecthttp://en.wikipedia.org/wiki/Materialhttp://en.wikipedia.org/wiki/Megastructurehttp://en.wikipedia.org/wiki/Megastructurehttp://en.wikipedia.org/wiki/Megastructure


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Cont..


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Cont..


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Laser launch systems could provide low-cost spaceaccess and also resolve the growing problem of

nuclear waste


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DISPOSAL INTO SPACE

DISADVANTAGE

Space disposal is impractical because

of the number of launches that would be

required

Establishing international agreements

on how such a program would beoperated and regulated would also be

difficult


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Scientists looked at burying

radioactive waste beneath unpopulated

remote IslandsIslands that were considered potential

candidates lacked valuable resources

and far away from large continental

landmasses


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ISLANDS


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Geological structure of Islands should beproperly investigated because some Islands

structures allow seawater to penetrate

underlying rock. Water could contribute to

waste container corrosion, releasing of

radioactive particles

Finland is pursuing the option of disposing

its nuclear waste in a stable rock massunderneath a near-shore island


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DISADVANTAGE

Risks associated with ocean transport

for remote island disposal

Many islands experience frequent and

intense earthquake and volcanic activity

Potential for opposition from other

countries


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GROUND DISPOSAL

Technically feasible, provides a wastedisposal solution that keeps the public

safe

Provides for security from intrusion

Prevents the diversion of nuclear

materials for harmful purposes

Protects the environment for both the

short and long term


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Cont..

Best solution to the critical problem ofhigh-level radioactive waste disposal is

to place it in solid rock deep

undergroundSite characterization studies will

determine how well the site's geologic

and hydrologic setting could isolatehigh-level waste from the environment


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ABOVE GROUND DISPOSAL

Above ground storage is a temporary

management solution

Waste could be put in secure storage

above ground until better technologies

become available for the permanent isolation

of the wastes from man's environment


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Cont..

This allows for the material to be moreeasily observed and any problems detected

and managed, while the decay over this time

period significantly reduces the level of

radioactivity and the associated harmful

effects to the container material


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NEAR SURFACE DISPOSAL

The shallow land burial is

characterized either by a mined cavity

or a repository in a shallow ground(within tens of meters of the surface)

provide adequate containment for short

lived low and intermediate level waste


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Cont..

Disposal of solid low-level wastes

containing radionuclides by burial inshallow trenches was initiated during

World War II

Very low activity radioactive waste

and exempt waste are often acceptable

for disposal in landfill sites used fordomestic and industrial


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Cont..

The near surface disposal depends onthe assumption that, by the end of theinstitutional control period, the activityof the waste will have decayed to

harmless levels

The safety standards are met by theconstruction of concrete walled

trenches reinforced by steel andprovided with hydro insulation


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VAALPUTS SOUTH AFRICA


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ASSE - GERMANY


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DEEP UNDERGROUND

DISPOSAL

Deep underground repository is

required for some long lived low

and intermediate level waste and

for high level waste

C t


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Cont..

Underground disposal is preferred

because the life times of some of the

radionuclides present in the certain

categories of waste are long by the

human standards but short in

comparison with geological time

C t


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Cont..

Deep geological disposal on land is

the most appropriate means forisolating such wastes permanently fromman's environment

The depth required for geologicaldisposal depends on the geologicalenvironment of a specific site and the

amount and type of waste to bedisposed off

C t


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Cont..

The basic requirement for any

geological formation is its ability tocontain and isolate the radioactive

wastes from man's environment

Radioactive wastes present nohazard while they remain in a deep

underground repository because of

their depth of burial (several hundredsof meters or more)

C t


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Cont..

Geological units under considerationare rock salt, argillaceous formations

(clays), and a range of crystalline rock

formations including granite, tuff,

basalt, and various metamorphic rock

types

WHY GEOLOGICAL FORMATION AS


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WHY GEOLOGICAL FORMATION ASA SUITABLE DISPOSAL SITE

Geological formations have existed in an

undisturbed form over much extended periods

of time, upto many millions of years and

having huge masses (both vertically andlaterally)

It can therefore be safely assumed that at

least some of these will remain stable in futurefor million years periods of time

FAVOURABLE GEOLOGICAL


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FAVOURABLE GEOLOGICALFORMATIONS FOR UNDERGROUND

DISPOSAL

EVAPORITES (ROCK SALT)

Common evaporates on earth. Composedsodium chloride (NaCl). Rock salt occurs

in nature in two structural forms:

Bedded Salt Deposit

Salt Domes

Cont


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Cont..

Thickness: Few meter to many

hundreds of meters

Properties: Normally salt domes

contain enormous masses of rock saltreaching upto thousand of cubic

kilometers with depth extending deeper

than 2000 meter or even 10,000 meters

Cont


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Cont..

A salt dome is a type of structural

dome formed when a thick bed of

evaporite minerals (mainly salt, or

halite) found at depth intrudes

vertically into surrounding rockstrata

SALT DOME
http://en.wikipedia.org/wiki/Dome_%28geology%29http://en.wikipedia.org/wiki/Dome_%28geology%29http://en.wikipedia.org/wiki/Evaporitehttp://en.wikipedia.org/wiki/Halitehttp://en.wikipedia.org/wiki/Stratumhttp://en.wikipedia.org/wiki/Stratumhttp://en.wikipedia.org/wiki/Halitehttp://en.wikipedia.org/wiki/Evaporitehttp://en.wikipedia.org/wiki/Dome_%28geology%29http://en.wikipedia.org/wiki/Dome_%28geology%29http://en.wikipedia.org/wiki/Dome_%28geology%29


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SALT DOME

Cont


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Cont..

Favorable Parameters:

Impermeable to liquids and gases

Natural plasticity(Prevent the

occurrence of fracture and joints atpressure)

Stress relieving capability(Salt heal

the joints and fracture as a result of

blasting and mining)

Cont


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Cont..

High Thermal conductivity (thishelps in heat dissipation from high

level, heat generating waste)

Good radiation shielding

Low seismicity

Free from circulating ground water

Cont


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Cont..

ARGILLACEOUS ROCKS

(CLAY, CALY STONE, MUD STONE, SILTSTONE)

Having fairly high properties and posses

following additional advantages incomparison to the rock salt:

Clay minerals are insoluble in circulating

water.Most clay minerals exhibits good sorption

(sorption & adsorption characteristics)

CLAY ROCK


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CLAY ROCK

IGNEOUS ROCKS


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IGNEOUS ROCKS

INTRUSIVE ROCK(Normally form at depth e.g.

Granite, Gabbros)EXTRUSIVE ROCK(Formed dumping volcanic

activity at surface of the earth e.g. Basalt, Tuffs

etc.)Crystalline rocks include volcanic and plutonic

igneous rocks exhibit very low porosity, largely

impermeable, very high stability, good sorptionproperties and having no chemical aggressive

components Dimension: Vary from few square

kilo meters to several thousand square meters

IGNEOUS ROCK FORMING PROCESS


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IGNEOUS ROCK FORMING PROCESS

Granite (left) an intrusive igneous


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Granite (left), an intrusive igneousrock, Obsidian (right), an extrusive

igneous rock

METAMORPHICS ROCK


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METAMORPHICS ROCK

Metamorphic rocks form from heat and

pressure changing the original or

parent rock into a completely new rock

METAMORPHICS ROCK


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METAMORPHICS ROCK

GNEISS ROCKS t hi Thi


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GNEISS ROCKSare metamorphic. Thisis the altered shape of Granite due heat

and pressure change

SCHIST ROCKS are metamorphic


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SCHIST ROCKS are metamorphic.These rocks can be formed from

basalt, shale and slat. Throughtremendous heat and pressure


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Disposal Options for Radioactive Waste (K.M. Ghazali)

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