Rehabilitation and environmental monitoring of former uranium mines in France
Rehabilitating mine sites after operations
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The open pit of the
rehabilitated
Commandery - Mining Division
of the Vendée (France) |
At the end of the operating period, AREVA rehabilitates and revegetates mine sites and monitors them radiologically and environmentally to watch and control their development. The group also monitors ground movements and erosion resistance. There are two primary purposes for this monitoring:
to protect public health and safety near the sites,
to minimize environmental hazards and impacts.
Since the beginning of the group’s mining operations, AREVA has invested more than 300 million euros to dismantle mining facilities and rehabilitate mine sites in France, Gabon, the United States and Canada at the end of their operations.
In France, mining for uranium ore ceased in 2001 when the economically recoverable deposits were depleted.
Uranium was mined at 210 sites in France scattered all over the country. Although fewer than half of these sites were operated by AREVA and its subsidiaries, the group is providing a public service by rehabilitating and monitoring all of the sites, in accordance with its agreement with the French government.
Responsible operations
Mine rehabilitation is an industrial operation in its own right and is conducted on solid scientific and technical grounds. Through consensus building and adherence to regulations, site rehabilitation seeks to:
ensure public health and safety,
minimize the residual impacts of legacy operations,
limit the use of space by legacy sites,
ensure that they harmonize with the landscape.
These operations are conducted in complete transparency. They are supervised by the regional departments of the ministries of research, industry and the environment (DRIRE) as well as by the nuclear safety authority (ASN) and the department of health and social affaires (DASS). Organizations for consensus building and analysis (CLIS local information and monitoring commissions, pluralistic study groups) were also created to respond to the expectations and questions of the different stakeholders.
The rehabilitation of mine sites requires real know-how, which is why a single operator is usually chosen. The French government chose AREVA for this mission, including the rehabilitation of sites that the company did not operate, due to its recognized expertise in natural uranium and its commitment to social responsibility. With a rehabilitation budget of 4 to 5 million euros per year, AREVA has 100 specialists in health, radiation protection, geology and the environment working on this subject and performs close to 10,000 analyses every year.
 What are mine tailings?
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An example of mine site rehabilitation for subsequent reuse: the Ecarpière site operates a solar energy park
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Natural radioactivity and artificial radioactivity
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The Limousin GEP: a real answer to societal expectations following the end of uranium mining operations in France
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What are mine tailings?
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The example of Écarpière
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Natural radioactivity and artificial radioactivity
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Mine tailings – L’Ecarpière (France) |
Definition of mine tailings: earth, sand or rock that does not contain usable uranium ore or that does not contain uranium at all, but that must be extracted to gain access to the ore itself. These substances have little or no radioactivity.
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Until 1984, part of this rock was used in the public domain for embankments, parking lots, foundations, traffic circles, etc.
In 1984, the group asked SCPRI, the department of protection from ionizing radiation (now IRSN) to issue standards for the use of these tailings. This was to control what end-users could do with it and to monitor the radioactivity of these materials.
Use restrictions were thus imposed, particularly for the construction of housing, public buildings, etc. Beginning at that time and at its own initiative, AREVA published an annual report that tracked and rigorously monitored mine tailing management.
The use of mine tailings as construction fill is age-old, well known, public, studied (pluralistic study) and without health effects. No one at present can estimate the quantity of mine tailings (fill) given to municipalities and individuals by former mine operators. The backfill is by nature barren rock (i.e. does not contain uranium ore). Deducing that radioactivity levels in all of the tailings combined is greater than natural radioactivity based on a few hot spots does not make sense.
Proof of this was given by the aerial detection campaign run by the CEA, for example, which showed that roads in the Forez region of France, some of which were made with the mine tailings, are not radioactive. Only two locations were above normal levels: the Poyet Mill and the square in front of the Mondière sawmill. As soon as this information came to light, AREVA took remedial action.
Similarly, the prefect of the St Priest la Prugne region sent 4,400 copies of a questionnaire to local residents to survey the use of mine tailings; 55 responses were received and all 80 or sites identified in the questionnaires as having used mine tailings were investigated. The regulatory authorities set an exposure limit of 0.5 mSv (i.e. half the legal standard), leading to cleanup of 8 sites. AREVA still has 1 site to clean up. |
Mine site rehabilitation for subsequent reuse: the Ecarpière site operates a solar energy park
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Ecarpière: mine site rehabilitation |
Having once produced uranium, the Ecarpière site near Nantes, France, is about to get a second life. Solar panels will be installed over a 12-hectare area (30 acres) to generate electricity.
The project should be completed by the end of 2009. Managed by AREVA, the project is in perfect alignment with the directives of the “Grenelle de l'environnement" Environment Round Table: by 2020, 23% of the electricity generated in France will come from renewable energies.
The solar panels will be placed 1.5 meters from the ground, capturing solar energy to generate electricity. This photovoltaic plant could begin to produce energy in the fourth quarter of 2009. The site will contribute some 5,000 megawatt-hours per year to the national grid. That’s enough to supply energy to a small town of 3,500 inhabitants.
From uranium to solar energy, in just one step. Other similar projects are on the drawing boards in places such as the Hérault department and the Forez area (France). |
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Radioactivity is a natural phenomenon. It is caused by the ability of the nuclei of the atoms of some radioactive bodies to transform spontaneously into other atoms (radioactive or otherwise) while releasing energy-carrying radiation.
It is found:
in the ground and in earthen materials (terrestrial radiation),
coming from the sun (cosmic radiation),
and even in the human body (potassium-40, carbon-14).
Humans have learned how to produce radioactivity artificially for the requirements of medicine and industry. Whether natural or artificial, the characteristics and effects of the radioactivity are identical.
In France, 70% of the radioactivity to which a person is exposed is of natural origin, while 30% comes from "artificial" radioactivity, mainly from medical uses. The average annual dose to an individual from natural sources is 2.4 mSv; total exposure is about 3.3 mSv.
Exposure to radioactivity
Distant: the radiation is emitted by a compound located more or less far away from the human body. This is known as external exposure or irradiation.
By absorption: The radioactive product is absorbed by the respiratory or digestive tracts or through the skin (via open sores, for example), and the radiation is emitted directly to the cells. This phenomenon is known as internal exposure or contamination.
By contact: radioactive particles can be disseminated on clothing or on the body (hair, nails, skin) without penetrating the body. This is external contamination.
Biological effects of radioactivity on humans
Deterministic effects: at high doses received instantaneously, radioactivity induces observable effects almost immediately. These effects are expressed as a dose threshold equal to or greater than 500 mSv (burns, nausea, death of exposed organs).
Random effects: below 500 mSv, there is no observable effect over the short term. However, effects may appear later, several years after the exposure, but not systematically (mainly cancers).
The biological effects of radiation are identical at identical doses, regardless of whether the source is natural or artificial.
 Read the topic sheet: Learning more about radioactivity (2005 publication)
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Consult the
IRSN website.
Yellow cake
7 training campaigns and 99 Japanese trainees since 2001
Yves Martin
