Complex sentence: One reactor of similar design as the X- 10 reactor is still in operation today the Belgian BR-1 reactor, which is used for scientific purposes, such as neutron activation analysis, neutron physics experiments and calibration of nuclear measurement devices.
Split into simpler sentences: One reactor of similar design as the X- 10 reactor is still in operation today, the Belgian BR-1 reactor. It is used for scientific purposes, such as neutron activation analysis, neutron physics experiments and calibration of nuclear measurement devices.