Radon leakage assessment in a controlled radon laboratory

As part of the activities to have a radon calibrated laboratory in Mexico, a DOSEman, an Alpha GUARD and a Germaniumdetector were used to measure the radon concentration of a radon source chamber. The two first detectors were also used todetermine the radon concentration in the laboratory during normal operation of the chamber and under a controlled radon leakageexperiment.Radon concentration in the chamber was determined with the Germanium detector through the γ-emission from the radondecay products 214 Bi and 214 Pb. The error in those activity measurements was 3.5%. The difference between these measurementsand the DOSEman was 3%. The experimental radon decay curve, as determined from the Alpha GUARD detector, differs 2%from the expected value.The source radon chamber is located in a licensed 280 m 3 volume laboratory. The radon chamber was left opened during aweekend to investigate the increase of the radon concentration in an extreme radon leakage case. The highest radon-concentrationincrease was 60% above background showing no working risk in the worst radon leakage case.