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GLOSSARIES
1. Technical glossary
> Hulls
Pieces about 3 centimeters long produced by the shearing of the metal cladding
(fuel rods) that had contained nuclear reactor fuel.
> IAEA (International Atomic Energy Agency)
International organization under the aegis of the United Nations (UN) whose role is
to promote the peaceful use of nuclear energy and to verify that nuclear materials
in users’ possession are not diverted to military uses.
> INES (International Nuclear and Radiological Event Scale)
International scale designed by the IAEA to facilitate communication about nuclear
events. It provides comparative elements that can be used to assess the seriousness
of an event. The scale ranges from level 0 (deviation with no safety significance) to
level 7 (major accident with considerable health and environmental consequences).
Three criteria apply in the application of the INES:
p
offsite radioactive releases;
p
the consequences inside the installation (damages or personnel injuries);
p
degradation of defense in depth.
> Information commission
Established near nuclear sites falling within the realm of National Defense whose
mission is to inform the public on the health and environmental impacts of the
nuclear operations.
>
In situ
recovery
Mining method consisting of recovering a mineral by injecting an acidic or alkaline
oxidizing solution directly into the geologic stratum containing the mineral, thus
dissolving it. The term “in situ leaching” is also used.
> Instrumentation and control system
Combination of electrical and electronic systems used for control, i.e. to perform
measurements, operate control systems, and ensure the operating safety of a
nuclear power plant or any other complex industrial system.
> Internal emergency management plan
Describes the organization, response methods and resources to cope with
emergency situations (incident or accident) to protect personnel, the public and
the environment from radiation, and to maintain the safety of the regulated nuclear
facility.
> Internal operation plan (
Plan d’opération interne
, POI)
Describes organizational procedures and resources available at an industrial site to
minimize the consequences of a potentially major disaster for people, property and
the environment. It may be required by regulation, pursuant to article R.512-29 of the
French Environmental Code (environmentally-regulated facility with AS classification,
any other facility following a prefectural decision, and certain special facilities such
as storage depots of more than 50,000 m
2
).
> Ionizing radiation
Flux of electromagnetic waves (radio waves, light waves, ultraviolet or X rays, cosmic
rays, etc.), of particles of matter (electrons, protons, neutrons), or of a group of such
particles. The flux carries energy which rises with the wave frequency or with the
particle speed. The effect of radiation on objects and living organisms is to strip
electrons from the atoms that make up their matter (whether living or inert), leaving
ionized atoms in their wake, which carry electrical charges, hence the generic name
of “ionizing” radiation.
> IPCC (Intergovernmental Panel on Climate Change)
Created in 1988 at the initiative of the G7 countries and made up of UN experts,
the IPCC is now part of the World Meteorological Organization in the framework
of the UN Environment Program. Its role is to assess scientific, technical and
socioeconomic information concerning the risk of human-induced climate change.
In this regard, it publishes several reports that forecast, among other things, an
average increase in global temperatures in one century.
> Irradiation
Exposure of an organism or an organ to radiation when the radiation source is
outside the organism.
> IRSN (
Institut de radioprotection et de sûreté nucléaire
)
The French institute for radiation protection and nuclear safety, a public industrial
and commercial agency whose mission, in particular, is to conduct research and
assessments in the fields of nuclear safety, protection of people and the environment
from ionizing radiation, and nuclear materials safeguards. IRSN provides technical
support to the ASN and the HFDS.
> ISO standards
From the International Standards Organization. The ISO series 9000 standards set
organizational andmanagement system requirements for quality to demonstrate the
conformity of a product or service, in particular to customer requirements. The ISO
series 14000 standards set requirements for the environmental organization and
management system designed to prevent pollution and reduce the environmental
effects of an activity.
> Isotopes
Nuclides whose atoms have the same number of protons in their nuclei, but a
different number of neutrons. For example, three main types of uranium isotopes
are found in nature:
234
U (92 protons, 92 electrons, 142 neutrons),
235
U (92 protons,
92 electrons, 143 neutrons), and
238
U (92 protons, 92 electrons, 146 neutrons). All
of the isotopes of a given element have the same chemical properties, but different
physical properties (mass in particular).
> Isotopic assay
Ratio of the number of atoms of a given isotope of an element to the total number
of atoms of that element contained in matter. Isotopic assay is expressed as a
percentage.
> Isotopic separation cascade
Arrangement of separative elements (“stages”), which are interconnected to increase
the separative effect of a unit element. The gaseous diffusion and centrifugation
enrichment processes separate uranium-238 and uranium-235 by exploiting the
difference in mass between those isotopes. Because the separative potential of
these processes is low to very low, the basic step must be repeated a large number
of times in a cascade to achieve the desired level of enrichment. These elementary
stages take place in diffusers or centrifuges, which together form a cascade.
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REFERENCE DOCUMENT