With the Académie des Sciences in 2015

45 / 48

45
AVEC L’ACADÉMIE DES SCIENCES 2015
L’évolution de l’ozone atmosphérique – Le point en 2015
Ed. Lavoisier Tec&Doc. October 2015
This report71 is devoted to the state of observations and research on atmospheric ozone. It
updates the data presented in two previous reports of the Académie des Sciences, whose
scientific content remains valid: Ozone et propriétés oxydantes de la troposphère (Lavoisier,
1993) and L’ozone stratosphérique (Lavoisier, 1998).
The report provides an update on the evolution of tropospheric ozone (lowest atmospheric
layer), whose increase is detrimental to health and vegetation, and stratospheric ozone,
which made apparent the first signs of anthropogenic change in the environment and whose
destruction caused fear that the ultraviolet solar flux on the planet might harmfully increase.
Ozone involves two distinct and seemingly contradictory subproblems: there is too much
ozone in some areas of the troposphere (especially near the cities) and not enough in some
areas of the stratosphere (particularly above the Antarctic). The report highlights these distinct
phenomena, which should not be confused with each other, as their potential remedies are
not of the same nature.
The problem of ozone equilibrium in the atmosphere and that of climate are a priori different. However, the state of a constituent
in the atmosphere is influenced by the characteristics of the environment; an interaction between the two problems is therefore
inevitable. Such various interactions are presented in the report.
Sciences du démantèlement des installations nucléaires
Éd. EDP Sciences – Collection Les ateliers de l’Académie. November 2015
In France, nine nuclear power reactors are being dismantled. Of the 58 nuclear power reactors operating, 48 should reach the end of
their lives before 2050. This situation is common to the industrialized nations that exploit nuclear energy: there are 75 in the European
Union and 29 in the United States.
These dismantling sites share specific features that distinguish them from other demolition
sites: radioactive materials are present, the radiation, ingestion or accidental inhalation of which
may be dangerous. Specific techniques, devices and processes have been developed, and
the French teams have built a scientific and technical expertise of international reputation.
The Académie des Sciences organized a seminar on these issues, during which all aspects
of the disciplines concerned were discussed: the characterization of radioactivity sources,
radioprotection, logistics, physicochemistry, continuous mechanics, calculation codes, robotics,
returns on experience, training, horizon scanning and serious accident reports. The book
Sciences du démantèlement des installations nucléaires72 [The Science of Nuclear Installation
Dismantlement] provides an account of these workshops and an overview of the requirements
and conditions needed for dismantlement to be implemented. It takes an inventory of the key
scientific phenomena, describes current research projects and identifies those that should be
carried out for the sites under consideration to be released for unrestricted use while ensuring
the protection of workers and the public for the present time and the future.
71
72