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The nuclear
power programme of the country is a three stage programme.The first
stage of this
programme is based on Pressurised Heavy Water Reactors (PHWR)
which are fuelled by natural uranium. The requirement of natural uranium for these reactors is met from
the indigenous resources established by AMD. The second
stage envisages utilization of plutonium produced
and re-processed from the first stage. The third
stage is based on thorium for which not only
some breakthrough has been achieved but also further R&D
effort is in progress. The requirements of thorium would
be met from vast resources of the mineral - monazite (a thorium,
REE phosphate).
The
work spectrum of AMD is closely linked to different phases
of nuclear fuel cycle, viz.
| Front
end |
:
|
survey
for identification of atomic mineral deposits |
| Middle |
:
|
site
selection for nuclear power reactors |
| Back
end |
:
|
selection
of suitable sites for waste disposal |
The front-end activities are of major importance
and are carried out in the field with adequate laboratory support. The
principal activity is to identify three major group of
resources viz. (i) uranium, (ii) rare metal and rare earths
(Nb-Ta, Ce, Be, REE, Y), and (iii) beach sand minerals
containing minerals of thorium, titanium and zirconium.
Uranium Investigations
The field activities commence with remote sensing studies / airborne
surveys (ASRS) followed by ground geological,
geochemical, geophysical surveys (EGPG) on
different scales. Once ground anomalies have been established
by these methods, their subsurface continuity is probed by
core / non-core drilling and rarely
by exploratory mining. The laboratory studies are carried out
simultaneously to evolve models for exploration and for optimising
the recovery parameters. Once a deposit is established, it
is handed over to Uranium
Corporation of India Limited (UCIL) for commercial exploitation.
Investigations for RMRE
Resources
The mineral resources included in this group are columbite-tantalite,
beryl, spodumene, lepidolite and xenotime which generally occur
in pegmatites and riverine placers. The field investigations
commence with survey, followed by pitting / sampling to estimate
the grade of the occurrence. These minerals are then won by
excavating gravel portion of the pegmatites and by setting
up on-site small-scale recovery plants. Separation of these
minerals is done by physical beneficiation methods and the
recovered minerals are stock piled in the godowns of the Directorate.
Beach Sand Investigations
The beach sand minerals comprise of ilmenite, rutile, zircon,
monazite, garnet, and sillimanite which occur in different
concentrations along various coastal stretches of the country.
These mineral resources are sampled by auger drilling, conrod
bunka drilling, dormer drilling and reserves are estimated
by mineralogical analysis of both individual and composite
samples. These resource estimates are parted with Indian Rare
Earths Limited (IREL) and other state government / private
entrepreneurs on commercial terms.
Laboratory support
In order to support the above investigations, the Directorate
is equipped with various laboratories both at AMD headquarter
and regional centers. They not only provide useful information
to the field units but also design, develop, fabricate and
maintain many of the instruments required in the exploration
programme.
While in each Region there is a Physics, Chemistry and Petrology
laboratory, in the Headquarter at Hyderabad, there are other
laboratories also often functioning as a Group, viz.
Mineralogy-Petrology-Geochronology
Group
Radiation Standards and Analysis
Group
Instrumentation
Group
Chemistry
Group
Ore dressing
Group
Mineral
Technology laboratory
Environmental studies
Winning of minerals from the earth involves alteration of environmental
parameters and has always been a concern for the mankind. Atomic
minerals, especially uranium, being radioactive the concerns
of environment draw more attention. However, considering the
fact that uranium is packed with abundant energy, for comparison,
1 kg petroleum products produce 4 KWh electricity whereas 1
kg of natural uranium produces 50,000 kwh electricity the importance
of winning this metal from the earth assumes all the importance.
For planning and initiating remedial measures, if any, in a mining
activity, pre-project environmental data is therefore essential.
In the recent years, AMD has been generating the pre-project
environmental baseline data around the potential mining sites.
Towards the back-end activities, AMD is associated with the
site selection for nuclear establishments
Site selection for nuclear
power reactors
Nuclear Power Plant sites are subjected to stringent evaluation
at every stage from regional analysis to site specific investigations,
for which AMD carries out geotechnical studies during pre-construction
stage. It collates the available geological and seismotectonic
data for 300 km radius area around the site. Seismotectonic
maps on suitable scales are synthesized, ‘Active Faults’ identified
and the earthquake potential of the structural elements and
seismotectonic provinces is evaluated. Remote sensing studies
using satellite imageries and aerial photos followed by limited
field check are supportive supplements in this work. The output
of this endeavor has application in deriving the seismic parameters
that are used in the design to strengthen the foundation and
the structure to withstand the heavy loads and seismic shaking.
Similar studies are carried out for the sites for Heavy Water
Plants, Tailings Ponds and Irradiation Plants.
In the selected sites geological mapping of the reactor pits,
lithologging, petrographic studies of the borehole cores and
base-line radiation data collection are carried out.
Site Selection for Waste
Disposal
Nuclear industry generates radioactive waste (RAW).
Ultimate disposal of this waste is done in suitable geological
environment.
Consequently comprehensive geological study in relation to
all aspects of storage / disposal of RAW is a must before final
selection of sites of radioactive waste repository. AMD extends
the cooperation in the site selection of repositories, drilling
of the candidate sites and studying of the core samples in
order to evaluate the subsurface conditions, petromineralogical
characteristics and to generate samples for the testing of
engineering properties. Expert opinion is offered to the end
user on the investigative geological reports submitted by other
agencies.
Miscellaneous
In addition, some of the miscellaneous activities carried out
by AMD are as under
1. Site specific background radiation surveys were carried out
in Goa and Nepal for M/s. Kodak India Pvt., Ltd., for their
photographic film storage plants.
2. Radon Emanometry surveys were carried out in and around
Khilari following the 1993 earthquake and the radon anomalous
behaviour had shown coherence in time with seismic events.
3. As a member of the Task Force, AMD has contributed to
the revision of IS code in bringing about the ‘Criteria for
earthquake resistant design of structures, Part.1 General Provisions
and Buildings (Fifth Revision), IS 1893 (Part-1): 2002.
4. AMD contributes in the formulation of codes of AERB pertaining
to geological and seismological aspects and was a member of
Expert Committee for Seismic Qualification of existing DAE
installations (ECSQ).

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