A study of the behavior of bi-oriented PVC exposed to ionizing radiation and its possible use in nuclear applications

• Bi-oriented PVC specimens have been irradiated with γ rays and β particles.
• Up to 100 kGy mechanical properties of bi-oriented PVC are practically unchanged.
• A numerical simulation allows estimating PVC piping minimum lifetime.
• Achieved decontamination factors of PVC piping are satisfactory.
• Results suggest bi-oriented PVC piping is suitable for nuclear applications.

The paper discusses whether bi-oriented PVC, obtained by modifying the structures of polymers chains to enhance the mechanical properties of unplasticized PVC, could successfully replace metallic materials in industrial applications where radioactive fluids are processed and an intense field of ionizing radiation is present. Tests have been carried out in order to study the behavior of a commercial bi-oriented PVC when exposed to ionizing radiations. A numerical simulation allows comparing the effects of radiation expected on the pipe in nuclear industry applications with those resulting from the irradiation tests. Contamination and decontamination tests of bi-oriented PVC in contact with a radioactive solution have been performed too. Results show that the bi-oriented PVC can withstand high β and γ radiation doses (up to 100 kGy) without showing significant degradation in mechanical properties; bi-orientation of polymers chains in the bulk of material is not affected even to much higher doses (250 kGy); the decontamination of the material is satisfactory. The results suggest that tested commercial bi-oriented PVC could be considered in nuclear industry applications.