Analysis, calculation, and measurement research on the background composition of the low background laboratory in the Suzhou Nuclear and Radiation Monitoring Technical Station, China

Low background laboratory with good shielding performance can effectively reduce the indoor background value and minimize the effect of background on the measurement results of low background [Formula: see text] spectrometers. In response to the need for the construction of a low background laboratory at the Suzhou Nuclear and Radiation Monitoring Technical Station in China, this paper combines theoretical analysis, on-site measurements, simulation calculations, and scale-down experiments to study in detail the background components of cosmic rays, radon and its daughters, the Earth’s natural [Formula: see text] radiation, and the radiation from building materials. The results show that the natural [Formula: see text] radiation and radon and its daughters have little influence on the low laboratory background, and the main contribution comes from cosmic rays and radiation from building materials. The total background values measured and calculated for the two main functional rooms of the low background laboratory, the steel room and the lead room, are 34.85[Formula: see text]nGy/h and 29.09[Formula: see text]nGy/h, respectively, which are lower than the corresponding background control target values of 40.00 nGy/h and 30.00[Formula: see text]nGy/h; the values obtained from the scale-down experiments are 27.27[Formula: see text]nGy/h and 18.36[Formula: see text]nGy/h, thus verifying that the current design of the main functional rooms are able to achieve the background control objectives.