The Steam Generator Leakage Monitor SGLM 504 is used for detecting the gamma radiation from activation or ﬁssion products in the secondary loop of pressurized water reactors (PWR), which is an indication of a leakage in the physical barrier between the primary and the secondary loop (e.g. N-16 or radioactive noble gases in the main steam line).
The gamma radiation is detected by the NaI(Tl) scintillation probe of type SG 66 R. Due to its robust design the detector can operate under difficult ambient conditions without requiring additional mechanical or thermal shielding. Integral part of the probe is a pre-ampliﬁer for pulse pre-processing and stabilization.
The associated signal processing unit DAK 250-i of the SGLM 504 forms part of the proTK™ platform of digital measurement channels and has been designed and is qualiﬁed to meet the requirements of the German KTA 3505, the IEC 60780 and the IEEE 323 for class 1E systems. The software of the DAK 250-i is certiﬁed for Cat. A functions acc. to the IEC 61226 and IEC 60880.