Appendix CRF - Part 3 - Northamptonshire County Council

dose. A measure of the energy deposited by radiation in a target. Absorbed dose, committed
equivalent dose, committed effective dose, effective dose, equivalent dose or organ dose,
depending on the context. All these quantities have the dimensions of energy divided by mass.
dose, absorbed, D. The fundamental dosimetric quantity D. The unit is J/kg, termed the gray
(Gy).
dose constraint. A prospective and source related restriction on the individual dose from a
source, which provides a basic level of protection for the most highly exposed individuals from a
source and serves as an upper bound on the dose in optimization of protection for that source.
The UK government has set a maximum dose constraint value of 0.3 mSv/year when determining
applications for discharge authorization from a single new source.
dose, effective, E. A summation of the tissue equivalent doses, each multiplied by the
appropriate tissue weighting factor: The unit of effective dose is J/kg, with the special name
sievert (Sv). The committed effective dose is the effective dose that will be received by the
person over their lifetime as a result of radionuclides taken into the body e.g. by ingestion or
inhalation.
dose, equivalent, HT. The radiation-weighted dose in a tissue or organ. This takes account of
the different amounts of damage caused by different types of radiation eg alpha particles, gamma
radiation. The unit of equivalent dose is J/kg, termed sievert (Sv).
dose limit. See limit, dose. The value of the effective dose or the equivalent dose to individuals
from planned exposure situations that shall not be exceeded. For the purposes of discharge
authorizations, the UK has (since 1986) applied a dose limit of 1 mSv/year to members of the
public from all man-made sources of radioactivity (other than from medical applications).
effluent. Gaseous or liquid radioactive materials which are discharged to the environment. See
also discharge, authorized.
emanation. Generation of radioactive gas by the decay of a radioactive solid.
engineered barrier. See barrier.
environmental (impact) assessment. See assessment, environmental (impact).
environmental impact statement. A set of documents recording the results of an evaluation of
the physical, ecological, cultural and socioeconomic effects of a planned facility (e.g. a repository)
or of a new technology.
environmental monitoring. See monitoring, environmental.
equivalent dose. See dose, equivalent.
exempt waste. See waste, exempt.
exemption. The determination by a regulatory body that a source or practice need not be subject
to some or all aspects of regulatory control on the basis that the exposure (including potential
exposure) due to the source or practice is too small to warrant the application of those aspects.
See also level, clearance.
exemption & exclusion. A number of exemption orders have been made under RSA 1993
which specify the conditions under which materials or wastes, which are defined as radioactive
under the Act, can be made Exempt or excluded from some or all provisions of the Act. An
important exemption order is the Substances of Low Activity (SoLA) Exemption Order. SoLA
establishes a limit of 0.4 Bq/g for certain radioactive wastes that in effect is the limit below which
wastes are not treated specifically as a radioactive waste for purposes of disposal. The
Phosphatic Substances, Rare Earths etc. Exemption Order and the Uranium and Thorium
Exemption Order are also used to set the practical lower boundaries of what becomes LLW.
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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