Development Of Fast Neutron Shielding Suit With Human Exoskeleton Robot

The importance of nuclear safety in national security has become increasingly prominent,and the radiation safety of nuclear professionals is particularly important.There are large doses of gamma rays and fast neutrons in the certain isotope production line of a company of China National Nuclear Corporation,which poses a higher health risk to the operators.At present,there are few finished fast neutron protective clothing on the market and are not targeted to specific neutron energy spectrum.In order to improve personnel safety,the company commissioned the research team to develop a fast neutron protective suit with a shielding rate of at least45%for on-site neutron source items and 150 ke V gamma ray external radiation dose.This paper uses the technology of human exoskeleton robot to load protective clothing to improve the carrying and walking ability of the human body,so that the design upper limit of the thickness and quality of the protective clothing is controlled within 8 cm and 40 kg.Under the limitation of quality and thickness,the Monte Carlo program MCNP5 is used to simulate and study the shielding performance of composite shielding materials(containing different ratios of carbon,hydrogen,boron,and lead)to neutron and gamma radiation.Then,various shielding samples and plug-ins were prepared and tested for their uniformity and mechanical tensile properties,and a lead-boron-polyethylene shielding material with higher cost performance was obtained.According to the shielding suit design drawing,the shielding plug-in was processed,the protective suit was assembled and combined with the booster exoskeleton to form a set of human exoskeleton fast neutron shielding suit.Finally,it passed the radiation dose shielding rate test of the ²²⁶Ra-Be neutron source and the²⁴¹Am gamma source and passed the acceptance.In summary,the following conclusions are obtained:In this paper:(1)The fast neutron shielding suit and exoskeleton technology were combined for the first time in China.A prototype was successfully developed,which accumulated experience for the subsequent development of mature models.(2)Calculated the optimal ratio of C,H,B,Pb mass fractions under the conditions of on-site neutron source terms and 150 ke V gamma rays given by Party A.When the shielding rate of the two radiation doses is at least 45%,it is 77.3%,12.7%,5%,5%.At this time,the shielding thickness of the lead-boron polyethylene is 4 cm,which is far better than the thickness that Party A intends to design and process,reducing the quality,increasing the flexibility, and saving costs.(3)The mechanical exoskeleton has a rated load of 40 kg,a working time of 1.5 hours,a mass load of 100%when stationary,a load of 60%when dynamic, and a walking speed of 3 km/h.