检修期间核电安全壳内挥发性有机化学品的挥发特性研究

It is difficult to dynamically determine the concentrations of volatile organic compounds (VOCs) in atmosphere of nuclear power containment, leading to a difficulty for evaluating the consequent fire disaster risk during pressure test. Six VOCs were tested qualitatively and quantitatively using an online system to obtain their dynamical volatilization curves and corresponding equations were fitted, and the volatilization rate equations were further numerically obtained. Setting 0.5 mm liquid membrane of each chemical during test, the volatilization periods of each chemical were calculated according to the volatilization rates determined in the volatilization rate at time 1 h and 2 h. The results suggest that as the most abundant chemical, Weidil cleaner takes 23.46 h (r(t=1 h), 40℃) and 33.31 h (r(t=2 h), 40℃) for volatilization according to the calculated results, and the tested volatilization period reaches 27.40 h; for screw cleaner, the calculated volatilization periods are 49.59 h (r(t=1 h), 40℃) and 69.43 h (r(t=1 h), 40℃), respectively, and the tested volatilization period reaches 60.00 h. According to the longest calculated and tested volatilization period, the ventilating time for pressure test of nuclear power containment can be obviously shortened. This approach is expected to optimize the pressure test time, and promote power plant efficiency.