OSIRIS REACTOR - Centre de Cadarache - CEA

14THE OSIRIS REACTORCEA••• NUCLEAR ENERGY AUTHORITYControl systemThe control system is based on the use of 2 programmable controllers.One of the controllers acquires and processes all the data to control the reactor from the point of view of safety and a comfort.Reactor control room.The other controller acquires and processes: the information required to monitorthe main auxiliary systems of the reactor, the parameters strictly necessary formanual control of the reactor that is safebut less comfortable.This organization ensures continuity ofoperation in the event of failure of one ofthe two controllers.A central calculator connected by networkto the safety and control controllers, collectsall their output and processes the dataoff-line. The central calculator is connectedto a high-speed data acquisition centre,which is used to supervise 12 analogchannels with a sampling period of 10 -2 sand 256 logical channels (including thelogic on-off channels) with a resolutionof 3.10 -3 s.Radiation protectionBecause of the risks present in the facility, the measures taken to protect against radiation relate in particular tothe detection of external beta and gamma irradiation, and atmospheric contamination by radioactive dust or gases.A network of detectors is used to supervise the buildings where such risks exist.Each measurement is processed individually by a processing unit that develops the physical value that can be exploited direct.This calculator is connected to a polychrome display unit located in the control room, which provides a map of the levelof activity of all the buildings supervised. These buildings contain signal boxes equipped with sound and light alarms for thevarious radiation protection thresholds, providing the technicians present with precise information about the actionto be taken.To supplement the information of the control team and help it in monitoring, a mimic panel shows the state of all the sensorsand a series of multichannel records is used to continuously monitor the activity of certain areas according to the operator’swishes.