Solid Radioactive Waste Strategy Report.pdf - UK EPR

EPR UK
N° NESH-G/2008/en/0123
REV. A PAGE 95 / 257
Power and Operating History
This EPR operating programme assumed for the activation calculations is as follows:
· 38 operating fuel cycles of 18 months (100% nominal power) followed by plant
shutdown of 16 days;
· A longer plant shutdown is considered every 10 years (40 days);
· The total operating time is 60 years;
· The thermal power is 4500 MWth.
Activation Results
Steels
Based on the results of the activation calculations, steels have been grouped into three
families of ILW dependent on activity levels:
· The most activated:
o Neutron shield and lower support plate;
o Specific activity associated with 60 Co ~ 2.1E+9 Bq/g for raw waste 5 years 3
after shutdown.
· The intermediate activated:
o
o
Core barrel, upper core plate, flow distribution device and upper support
columns (which are located under the upper support plate);
Specific activity associated with 60 Co ~ 3.6E+8 Bq/g for raw waste 5 years
after shutdown.
· The less activated:
o
o
Pressure vessel + cladding (in the active region of the fuel assemblies);
Specific activity with 60 Co ~ 2.8E+5 Bq/g for raw waste 5 years after
shutdown.
All other internal structures, namely the upper support columns (above upper support plate),
the upper support plate, the upper support assembly, the pressure vessel (upper and lower
fuel assemblies) and vessel cladding (upper and lower fuel assemblies) will be classified as
LLW at the time of production.
Concrete
It is predicted that the following categories of waste will be generated for the reactor pit:
· 5 years after shutdown:
o
o
o
60 cm depth of concrete is ILW;
Then 90 cm depth is LLW;
The remainder is VLLW.
· 40 years after shutdown:
o 80 cm depth is LLW;
3 Based on 60 years of electricity production for an EPR followed by an assumption of
immediate dismantling of a single reactor, the ILW resins (from primary circuit
decontamination) are produced in year 61 and ILW solid dismantling wastes between years
67 and 70. Therefore, 5 years after shutdown has been chosen to evaluate conservative
radiological characteristics.