A major milestone for BR3: final concrete blocks removed from bioshield
A first in Belgium as reference for conditional release
From modelling in 2020 to heavy cutting work since 2022 and the final transport last week: the last concrete blocks of the BR3 biological shield, whose disposal was permitted according to the principles of conditional release, have finally been disposed of in a conventional landfill. "It's a symbolic step in the dismantling of BR3. It marks the end of a complex process that began years ago and has served as a guide for future decommissioning projects," explains Jérôme Dadoumont.
Avoiding waste
Let us rewind to 2020. It was then that we mapped out the situation of the biological shield of BR3. Each reactor vessel of a pressurised water reactor is surrounded by reinforced concrete. The purpose of this concrete wall – known as the biological shield – is to block radiation. The shield of the dismantled BR3 pressurised water reactor was 15 metres high and 1.20 metres thick, amounting to nearly 2,200 metric tonnes.
"The golden rule for every dismantling project, however, is to minimise the amount of radioactive and conventional waste in a cost-effective way," continues Jérôme Dadoumont, dismantling expert at SCK CEN.
Declassification and final removal
No sooner said than done. Cutting work began in 2022: the concrete was scraped, hacked, or sawn off in layers. Each layer was assigned the most suitable purpose. The most remarkable final destination was category 1 landfill for industrial waste, to which about 1,000 tonnes of concrete went. "Since the remaining radionuclides lose radioactivity relatively quickly, disposal in a conventional landfill is the most optimal and ethically sound choice," stressed Jérome Dadoumont.
Reuse and cost savings
The 1,000 tonnes of the BR3 bioshield were removed with extreme care. The remaining 1,200 tonnes of reinforced concrete have been released and will be recycled during demolition of the building, as is common in conventional demolition and road construction, meaning that no radioactive waste of any kind remains.
"If we had processed the material in the usual way, much of it would have ended up in a surface disposal facility for radioactive waste. Enough for 200 to 300 monolithic blocks. Aside from being an ethically sound choice, the conditional release process also offers significant financial savings," says Jérome.
This operation required thorough inspections, extensive impact studies and the necessary licences, a process that required dedication and meticulous planning. The decommissioning project of BR3 continues, of course, and with this important step behind us, our experts are looking forward to the next stages of decommissioning with confidence and determination.
Cost-effective answers for the future
The removal of the biological shield is not only an important milestone for the SCK CEN team, but also offers an opportunity for the owners of facilities yet to be decommissioned. "Our insights have shown that material that is almost clean need not be processed as radioactive waste. This is particularly valuable to know, especially since the biological shield at commercial nuclear power plants often forms the bulk of short-lived low-level and intermediate-level radioactive waste."
As well as providing practical lessons on waste reduction, our know-how may also be of assistance when designing new reactors. The knowledge and experience we are gaining now can also be used in the future to dismantle facilities more efficiently and cost-effectively.
Do you have any questions or want to know how our BR3 case can assist with your decommissioning project?
Contact Guido Mulier, business developer for decommissioning at SCK CEN.
