Solid Radioactive Waste Strategy Report.pdf - UK EPR

EPR UK
N° NESH-G/2008/en/0123
REV. A PAGE 103 / 257
The dismantling scenario for the primary circuit is as follows:
· Preliminary decontamination of the primary circuit with CORD-UV type process in order
to:
o
o
Reduce dose rates to allow contact (“hands-on”) dismantling of many of the
primary circuit components;
Minimise volume of packed waste (reduction of required biological shielding)
even with production of secondary waste (Ion exchange resins).
· Preparation for primary circuit dismantling, dismantling of last auxiliary pipes;
· Export of the steam generators out of the reactor building for dismantling in a dedicated
workshop:
o
o
Separation and export of the upper sections of the steam generators to a noncontamination
area workshop (the upper sections will have only contacted fluids
from the secondary reactor circuits and thus would be highly unlikely to be
significantly contaminated);
Export of the lower steam generator section (containing the primary circuit tube
bundle) to the contamination area workshop constructed to accommodate this
size of component.
· Export and dismantling of the reactor coolant pumps;
· Dismantling and export of the main coolant pipes;
· Export and dismantling of the pressuriser;
· Preparation for internals dismantling with adjustment of the water level in the reactor
compartment;
· Dismantling of upper core internals associated with the pressure vessel head under
water on its storage stand in the reactor pool (the pressure vessel head is removed for
refuelling the reactor and has a dedicated storage stand within the reactor pit;
· Dismantling of thermal shield in the reactor compartment pool;
· Dismantling of lower core internals under water, on its storage stand in the reactor
compartment pool;
· Dismantling of reactor pressure vessel;
· Dismantling of reactor vessel head;
· Dismantling of activated part of the reactor compartment (the first 60 cm depth of
concrete at the level of the reactor core);
· End of primary circuit dismantling - Radiological decontamination and demolition of the
buildings.
This scenario for primary circuit dismantling and, by extrapolation, the complete reactor site
dismantling, is based on:
· Use of currently practised, realistic and achievable operations and techniques
guaranteeing the control of the dismantling; feasibility is demonstrated through the use
of techniques validated worldwide.
· Technical choice and operation modes reducing dose uptake to operators and members
of the public: