This paper carried out an optimization design and application study on a high temprature resistant borated polyethylene shielding material, according to the nuclear power plant source characteristics and special protection requirements. The composition of borated polyethylene shielding material was optimized based on the genetic algorithm and Monte Carlo methods, then it was realized by blending modification and graft copolymerization to improve the high temperature resistant, shielding and mechanical properties. Finally, comprehensive properties such as mechanical, neutron shielding, irradiation resistance and high temperature resistance experiments were verified with the ordinary borated polyethylene and polypropylene. Those just proved the optimized borated polyethylene shielding material has excellent performance comparatively, especially it could keep complete structure in a high temperature environment up to 190°C during 48 hours, meeting the requirements of radiation protection safety for nulear power plant completely.

A novel high-temperature-resistant W-B₄C-poly(4-methyl-1-pentene) (PMP) composite shielding material against neutron and gamma rays was developed and fabricated. Firstly, utilizing the ²³⁵U-induced fission spectrum as the source term, the compositional ratio of the W-B₄C-PMP ternary composite was optimized using the genetic algorithm-based GENOCOPIII program coupled with MCNP simulations. Then, the composite was fabricated through coupling agent modification, melt mixing, and hot pressing. Finally, the effects of coupling modification and tungsten content on the thermomechanical properties of the composite were investigated. Results demonstrated that functional groups from the silane coupling agent KH550 were successfully grafted onto the filler surfaces. For composites containing 30 wt% modified B₄C and 40 wt% modified W in the PMP matrix, the heat deflection temperature (HDT) increased by 18.5% and 19.1%, respectively, compared to their unmodified counterparts. The impact strength also improved by 31.6% and 5.0%, respectively. The variation trend of the composite’s modulus approximately followed the classical Einstein model, while its tensile strength and flexural strength conformed precisely to the model: ${\displaystyle \frac{{\mathsf{\sigma }}_{\mathrm{c}}}{{\mathsf{\sigma }}_{\mathrm{m}}}}=0.88{\mathrm{V}}_{\mathrm{f}}^{-0.02}$. Thermal analysis indicated that the composites possessed a melting point exceeding 230 °C, and their thermal stability improved with increasing filler content.