Link to the study - European Parliament - Europa

Policy Department D: Budgetary Affairs
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Selected example EDF: Chooz A
Chooz is the only pressurized water reactor currently being dismantled in France.
Chooz A was the first commercial PWR built in Europe and the first PWR that is being
decommissioned in France. Chooz A was commissioned by the Franco-Belgian Nuclear Energy
Company of the Ardennes (SENA), a joint venture created in 1960 by EDF and a group of Belgian
utilities.
Construction at Chooz A started in 1961 and generation commenced in 1967.
The plant was installed deep inside the bedrock of a hill in the Ardennes into two excavated
caverns where the reactor and auxiliary installations were accommodated. In the building at the
top of the hill were placed the emergency core cooling system and the ventilation stack. A steep,
wide access gallery containing pipework connects those buildings to the reactor cavern and the
nuclear auxiliary cavern 200 m below, 60 m from the side of the hill. A drainage system collects
water percolating through the hillside in case of potential contamination.
Chooz A was shut down in 1991, and the responsibility for decommissioning was transferred
from SENA to EDF, which had adopted a deferred dismantling strategy at that time. By December
1995, all the fuel had been removed from the facility and was dispatched to Cogema (now
AREVA).
Many works were started already in 1999, the circuits had been drained, industrial waste
removed and the turbine hall equipment dismantled.
EDF later set an ambitious target of completing decommissioning by 2016 (NEI 2010).
A public enquiry was carried out in 2006, and in September 2007 a decommissioning license was
issued authorizing total dismantling of the plant.
Dismantling, clean up and demolition of nuclear buildings on the hillside, dismantling of service
tunnel facilities (including the tunnel linking the cavern bottom to the other facilities on the site)
took place before 2008.
The decommissioning schedule foresees three time periods (Lelong 2011, NEI 2010):
2007-2008: planning work (ventilation, waste removal, etc.);
2008-2016: sub-steps dismantling of nuclear auxiliary cavern (2008-2012) and dismantling of
reactor caverns (2012-2016). Until 2016, the equipment within the caverns will be
dismantled except the apparatus needed to collect, monitor and release the drained water
from within the hill;
As of 2016: Decontamination and regeneration of the site.
The decommissioning operations are expected to be completed by 2020-2025.
After the end of the aforementioned works, the plant remains under surveillance for several
years. The water from inside the caverns shall be collected and tested until the radioactivity levels
are reduced (remaining radioactivity from reactor) so that the discharge can take place without
tests. At the end, the components remaining in the nuclear auxiliary cavern and the waste
treatment facility will be dismantled. After the finishing of these activities - planned to be
completed by 2020-2025, the underground structures will be emptied of electromechanical
components and their civil engineering structures will be decontaminated; subsequently, the
caverns will be partially filled to avoid the subsidence (NEI 2010).
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