A NEW CONVERSION PLANT: COMURHEX II
Global growth in the nuclear power sector will spur an increase in the demand for uranium, which will require conversion. To meet these growing needs, AREVA has decided to renovate and modernize its industrial conversion facilities by launching the COMURHEX II project.
Converting uranium ore into uranium hexafluoride (UF6) is a key step in the process leading up to nuclear fuel enrichment and production.
COMURHEX II is grounded in proven practices and techniques, and in technological innovations which will enable increased output, improved plant safety, and further reduction of its environmental impact.
The progressive starting of the units is planned from 2013 to 2015.
Growth in energy demand
With demand for energy growing, increasing supply problems, rising oil and gas prices, and intensification of the challenges introduced by climate change, nuclear power offers numerous advantages:
- Economic competitiveness
- Availability of supply, which will facilitate energy independence
- Non-polluting characteristics, thanks to low CO2 emissions
The demand for fuel will increase sharply over the coming years, driven by the construction of new nuclear power plants around the world and by the extension of the service life of current facilities. So the conversion units operated by the various industry players will have to be modernized or replaced. The industry players will have to boost their production capacities in order to meet market demands under future economic, regulatory, and environmental conditions.
COMURHEX II: AREVA is leading these developments.
AREVA is the first converter to modernize its industrial facilities for production of 15,000 metric tons of uranium per year.
The COMURHEX II site will modernize AREVA's industrial capacity with a blend of proven practices and technological innovations. Aim: to enhance production performance, further reduce environmental impact, and improve safety for the facilities.
COMURHEX II in NARBONNE
On the Narbonne site (Malvési), new units will be added like a replacement of existing installations and the most recent workshops will be perpetuated. In the interests of sustainable development, AREVA is building these facilities in accordance with the latest standards with respect to safety and environmental protection.
A new industrial building of around 2,500 m² meeting the latest structural standards is under construction on the COMURHEX site in Malvési. It will feature:
- A unit for the drainage and dissolution of ore concentrates, designed to improve product containment.
- A unit for thermal denitration of purified uranium, using an innovative process. This will allow us to stop using ammonia in this processing phase and to recycle nitric acid.
The purification unit will also be modified and two other buildings will be unveiled:
- A facility for treatment of raffinates produced during the purification phase. Once this has been connected to the future capture center for prestocked discharge, we will no longer have to resort to using lagoons.
- A new gas treatment system for the hydrofluorination unit.
Finally, AREVA will also install an industrial platform featuring, among other things, a control system to handle all of the water collected, as well as a closed-loop cooling water circuit.
COMURHEX II ON THE TRICASTIN SITE
A new plant will be constructed on the Tricastin site, to the north of the existing COMURHEX plant.
- A new hydrofluoric acid storage building with containment and enhanced safety systems.
- New electrolytic fluorine production systems applying the latest advances in electrolyzer technology.
- A new unit for the fluorination of UF4 into UF6 associated with a uranium tetrafluoride storage building and a contained storage unit for UF6 cylinders undergoing cooling.
- A liquid effluent treatment unit that generates less waste and reduces environmental releases.
THE CONSTRUCTION PROJECT WILL INVOLVE UNTIL 500 WORKERS.
Project management will be handled by AREVA's Chemistry Business Unit. Management of the contract falls under the Group's Engineering and Projects organization, which in charge of research, engineering, implementation, and monitoring of the construction site.
The COMURHEX II project required 1.5 million hours of design, engineering and construction management.
COMURHEX II brings together the latest advances and innovations from the AREVA group's Research and Development projects.
A major breakthrough: thermal denitration
This thermal denitration process was developed, perfected, and patented by the COMURHEX Research and Development team.
It allows us to:
- Stop using ammonia in this processing phase,
- Recover and recycle nitric acid.
Inverse osmosis: a global first
The first of its kind in the world, a filtration system enabling a significant reduction in water nitrate levels has been installed at Malvési.
This system, perfected in cooperation between COMURHEX and Ondeo Industrial Solutions (Suez Group) uses the principal of inverse osmosis applied in seawater desalination.
This filtration process involves forcing water through a semipermeable membrane. This results in a selective separation of nitrates, thus enabling denitration of industrial discharge.
Reducing even further the environmental impacts of operations was the overriding concern for the design and construction of the COMURHEX II plants.
Implementation of the new closed-loop cooling water circuit at the facilities in both Tricastin and Malvési site will provide a ninety percent reduction in the amount of water extracted from the environment.
That comes to a savings of 1.5 million m3 of extracted water per year.
The heat emitted by the electrolyzers in the future COMURHEX plant in Pierrelatte will heat the new buildings.
The fuel-oil boilers will be gradually replaced with electric or natural gas.
Reduction of greenhouse gases
Direct greenhouse gas emissions will be reduced thanks to the use of thermal denitration, as well as improvements in the hydrofluorination unit and replacement of fuel-oil boilers.
Elimination of liquid discharge
In the Tricastin site, the new discharge treatment station will significantly reduce reagent consumption and waste production, with a 50% reduction in fluorine consumption and a 60% reduction in potassium consumption.
Safety and Security
Safety and Security were a top priority in the design of the COMURHEX II project. New improvements have been made in worker safety, building integrity, and measures for the use of hazardous substances.
Optimized working conditions
The following new safety features and improvements in staff working conditions were incorporated into the development of the COMURHEX II project (Automated tasks, workstation ergonomics, etc.).
In order to protect the teams who will be working on the new industrial sites, and to prevent disruptions during implementation the COMURHEX II project, a special zone will be set up between the production and construction areas.
The facilities were designed to reduce the risk of an incident or accident, to limit their consequences, and to facilitate working conditions and operations. Special facilities will be installed in the new Comurhex II conversion plants in response to the latest nuclear safety requirements. For example, the new plants’ buildings were designed to withstand the most extreme flooding and earthquake scenarios (one-hundred-year flood, safe-shutdown earthquake*). These safety and reliability levels were reaffirmed during the Supplementary Safety Assessments carried out in 2011 following the Fukushima accident.
*safe shutdown earthquake: earthquake strength taken into account in the safety calculations, based on historically attested earthquakes
The processes implemented in the COMURHEX II plants will decrease consumption, and thus also storage levels, of ammonia and nitric acid.
Measures will also be taken to improve containment in areas where various materials are handled and stored: stuffing and stripping of uranium and chemical reagents.