Abstract: Radiation source and weak penetrating radiation from pumps, reactor refueling pools, steam generators and valves were monitored during several outages in Qin Shan phase II nuclear power plant. Radionuclides such as⁵⁸Co,⁶⁰Co,⁵⁴Mn,⁵¹Cr,⁹⁵Nb,⁹⁵Zr,¹²⁴Sb,⁵⁹Fe,⁵⁷Co and ^110mAg are mainly deposited on the surface of these devices. The emitted beta-ray energy is mainly in the range of 100 keV to 500 keV.$\dot{H}$·^*(10),$\dot{H}$·′(0.07) and $\dot{H}$·′(3) values on the surface of monitored equipment are given. The average value of $\dot{H}$·′(3)/$\dot{H}$·^*(10) of the three pumping equipment is 1.31±0.09,$\dot{H}$·′(0.07)/$\dot{H}$·^*(10) average is 7.8±0.4. The average value of$\dot{H}$·′(3)/$\dot{H}$·^*(10) of steam generator is 1.40±0.20,$\dot{H}$·′(0.07)/$\dot{H}$·^*(10) average is 15.1±3.2. The average values of $\dot{H}$·′(3)/$\dot{H}$·^*(10) of the four types of valve equipment is 1.32±0.17,$\dot{H}$·′(0.07)/$\dot{H}$·^*(10) average is 14.6±3.5. The average value of $\dot{H}$·′(3)/$\dot{H}$·^*(10) of the refueling cavity is 1.29±0.10,$\dot{H}$·′(0.07)/$\dot{H}$·^*(10) average is 8.5±1.1. The overall average value of $\dot{H}$·′(3)/$\dot{H}$·^*(10) of all weak penetrating radiation investigation equipment is 1.32±0.12,and the overall average value of $\dot{H}$·′(0.07)/$\dot{H}$·^*(10) is 11.4±4.1. Combined with the measurement results,it is suggested that the maintenance personnel in reactor coolant pump,the residual heat removal pump,and the steam generator should carry out the monitoring of ocular lens dose and skin dose, so should the decontamination personnel in the changing pool.

Key words: pump equipment, reactor refueling pool, steam generator, weak penetrating radiation