Appendix CRF - Part 3 - Northamptonshire County Council

Radioactivity & Risk
S12 This summary contains a short Annex which briefly explains radioactivity.
Humans are exposed to ionising radiation every day. This exposure comes from
background radiation.
S13 Humans can have additional exposure from other sources; for example having an
x-ray or flying in a commercial aeroplane results in additional exposure to ionising
radiation. It is necessary to limit exposure because there is a possibility of
adverse health effects.
S14 In the UK there is a consensus that for exposure to radioactivity the risk of a
fatality of 1 in 1,000,000 (one in a million) per year can be regarded by society as
a level of risk to a member of the public beyond which further reduction may not
be justified.
S15 A risk of one in a million is very low. For comparison the average annual risk of
death for the following is approximately:
Smoking 10 cigarettes per day 1 in 200
Natural causes for someone aged 40 1 in 700
Accidents in the home 1 in 10,000
Lighting strike 1 in 10,000,000 (1 in 10 million)
S16 The waste disposal process proposed has been designed such that the risk to
the public in the long term is broadly less than one in a million per year. This is
consistent with the risk guidance level set by regulatory guidance (ref 18) and is
better than the risk constraint established by the HPA guidance (ref 14) of 1 in
100,000 per year. This risk guidance level is achieved by limiting the radioactive
content and amount of the waste that the landfill can receive. Hence long term
public safety is an inherent feature of the proposal and does not depend on future
human actions.
S17 For unlikely intrusion events, including for example, if the landfill is excavated by
future society and the land reused for residential properties, a dose guidance
level has been used which is the lower end of the range indicated by regulatory
guidance (refs 18, 14).
S18 Over time radioactivity decreases because radioactive decay is a process that
eventually leads to the original wastes becoming non-radioactive. For some
types (radionuclides), this takes so long that it can be ignored, but for others the
effect is relatively quick and after only a few years or decades the waste
becomes essentially non-radioactive.
Application for disposal of LLW including HV-VLLW under RSA 1993,
for the East Northants Resource Management Facility:
Supporting Information
July 2009
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