Term Papers on Nuclear Power

Term Paper Title	Nuclear Power
# of Words	1836
# of Pages (250 words per page double spaced)	7.34

Nuclear Power

        Radioactive wastes, must for the protection of mankind
be stored or disposed in such a manner that isolation from
the biosphere is assured until they have decayed to
innocuous levels. If this is not done, the world could face
severe physical problems to living species living on this
planet.
        Some atoms can disintegrate spontaneously. As they do,
they emit ionizing radiation. Atoms having this property are
called radioactive. By far the greatest number of uses for
radioactivity  in Canada relate not to the fission, but to
the decay of radioactive materials - radioisotopes. These
are unstable atoms that emit energy for a period of time
that varies with the isotope.  During this active period,
while the atoms are 'decaying' to a stable state their
energies can be used according to the kind of energy they
emit.
        Since the mid 1900's radioactive wastes have been
stored in different manners, but since several years new
ways of disposing and storing these wastes have been
developed so they may no longer be harmful. A very
advantageous way of storing radioactive wastes is by a
process called 'vitrification'.
        Vitrification is a semi-continuous process that enables
the following operations to be carried out with the same
equipment: evaporation of the waste solution mixed with the
additives necesary for the production of borosilicate glass,
calcination and elaboration of the glass. These operations
are carried out in a metallic pot that is heated in an
induction  urnace. The vitrification of one load of wastes
comprises of the following stages. The first step is
'Feeding'. In this step the vitrification receives a
constant flow of mixture of wastes and of additives until it
is 80% full of calcine. The feeding rate and heating power
are adjusted so that an aqueous phase of several litres is
permanently maintained at the surface of the pot. The second
step is the 'Calcination and glass evaporation'. In this
step when the pot is practically full of calcine, the
temperature is progressively increased up to 1100 to 1500 C
and then is maintained for several hours so to allow the
glass to elaborate. The third step is 'Glass casting'. The
glass is cast in a special container. The heating of the
output of the vitrification pot causes the glass plug to
melt, thus allowing the glass to flow into containers which
are then transferred into the storage. Although part of the
waste is transformed into a solid product there is still
treatment of gaseous and liquid wastes. The gases that
escape from the pot during feeding and calcination are
collected and sent to ruthenium filters, condensers and
scrubbing columns. The ruthenium filters consist of a bed of
glass pellets coated with ferrous oxide and maintained at a
temperature of 500 C. In the treatment of liquid wastes, the
condensates collected contain about 15% ruthenium. This is
then concentrated in an evaporator where nitric acid is
destroyed by formaldehyde so as to maintain low acidity. The
concentration is then neutralized and enters the
vitrification pot.
        Once the vitrification process is finished, the
containers are stored in a storage pit. This pit has been
designed so that the number of containers that may be stored
is equivalent to nine years  of production. Powerful
ventilators provide air circulation to cool down glass.
        The glass produced has the advantage of being stored as
solid  rather than liquid. The advantages of the solids are
that they have almost complete insolubility, chemical
inertias, absence of volatile products and good radiation
resistance.  The ruthenium that escapes is absorbed by a
filter. The amount of ruthenium likely to be released into
the environment is minimal.
        Another method that is being used today to get rid of
radioactive waste is the 'placement and self processing
radioactive wastes in deep underground cavities'. This is
the disposing of toxic...

This is ONLY a preview of the article. If you would like to view the entire document, you must subscribe to Digital Term Papers. Please register below now!

Digital Term Papers has over 63,000 essays, term papers, and book notes online. Many paper sites will charge you hundreds of dollars for a single paper. Digital Term Papers only charges $14.95 for a one month membership with instant account activation!

Don't waste anymore time! Join NOW!!!

1 Month (automatic renewal) ($14.95)

3 Months (automatic renewal) ($29.95)

6 Months (one-time billing) ($39.95)

Pay by: