Appendix CRF - Part 3 - Northamptonshire County Council

Radiological Assessment 0820-2
Version 2
surface of the landfill is a practice that should be prevented through the
Environmental Permitting process. Aerosols from leachate may, however, be
generated during other types of leachate treatment either on or off-site,
particularly if this involves aeration. Leachate treatment may continue after
closure, but will end at the end of the control period. Use of leachate
following the loss of control may also lead to aerosol formation but
concentrations are likely to be lower than during leachate treatment.
Inhalation of dust, particles and gases from fires. Accidental fires in the waste
are a potential hazard at landfill sites with combustible wastes. A fire at the
site could lead to the release of radioactive particles and dust that could be
inhaled by workers and members of the public downwind of the site, and
could also lead to some gaseous releases. Waste fires may be associated with
the collection and utilisation of landfill gas at sites which accept biodegradable
wastes. Gaseous releases of radioactive material from flaring or other use are
included in the following pathway.
Inhalation of radioactive gas, i.e., 14 CO2, 14 CH4, 3 H, and radon. The first three
may be generated through microbial degradation or corrosion of the
radioactive waste. Landfill sites which accept biodegradable wastes are
required to collect and flare or utilise the gas, and this could disperse
radioactive gases that could be inhaled by workers and members of the public
downwind of the site. Radon is generated through the decay of Ra-226, which
in turn is a decay product of Th-230. Radon could be inhaled by workers,
members of the public downwind of the site, and occupants working or living
on the site after loss of control.
Ingestion of contaminated water. This pathway arises mainly through the
leakage of leachate through the engineering and into groundwater (Figure 5).
Once groundwater is contaminated, ingestion can occur through:
- extraction of contaminated groundwater via a well for drinking; and
- discharge of contaminated groundwater to surface water used for drinking.
Surface water may also be contaminated by the unintentional release of
contaminated leachate. Once surface water is contaminated, ingestion can
occur through:
- extraction of water for drinking.
Spillage of leachate may also contaminate groundwater used for drinking
water supply, but retardation and dilution are likely to mean that potential
doses through this pathway are less than those from surface water.
Ingestion of contaminated food. This pathway arises mainly through the
leakage of leachate through the engineering and into groundwater. Once in
the groundwater, radioactivity can contaminate food supplies through:
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