Boron‐containing nonwoven polymeric nanofiber mats as neutron shields in compact nuclear fusion reactors. (17th January 2022)

• Record Type: Journal Article
• Authors: Özcan, Mücahid; Kam, Erol; Kaya, Cengiz; Kaya, Figen
• Is Part Of: International journal of energy research. Volume 46:Number 6(2022)
• Page Start: 7441
• Page End: 7450
• Publication Date: 2022-01-17
• Subjects: amorphous boron -- electrospinning -- lightweight composites -- neutron absorption -- polymer nanofibers; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Power resources -- Research -- Periodicals; 621.042
• DOI: 10.1002/er.7652
• Languages: English
• ISSNs: 0363-907X

Abstract

Summary: Composite materials that contain thermally and chemically stable boron compounds are attractive candidates for applications that require high neutron absorption due to the large neutron absorption cross‐section of boron. Electrospun polymer nanofibers have a unique volume‐to‐surface area, incorporating carbon and hydrogen atoms in their molecular structure that could moderate and thermalize incident neutrons. Nonwoven nanofibers could in turn reduce neutron scattering and increase neutron absorption by providing large surfaces and better atom economy in the shield materials. The expected high absorption will result from improved neutron interaction with high neutron absorbance hydrogen, carbon, and boron atoms in the nanofibers through increased specific surface area and atom economy. In this work, elemental boron‐doped PVA polymeric nanofibers are produced for the first time to date for the application of neutron shielding. With the increasing demand for nuclear power generation and radiation therapies in medicine, the need for producing lightweight and flexible materials that could replace the traditional heavy metal/metal carbide‐based shields is vital. Similarly, the need for flexible materials that could shield neutrons is also becoming critical for aerospace applications. The effect of boron content on the quality of fibers and neutron shielding capacity is evaluated by using an Am‐Be neutron source. Characterization studies of produced nanofibers were carried out by SEM, TGA, FT‐IR, and XPS analyses. Results have shown that PVA‐based nanofibers doped with wt% 0.1 to 0.5 boron, having fiber diameter distribution between 60 and 330 nm range, could absorb up to 6% of neutron flux. Abstract : This manuscript reports on the production of electrospun boron‐containing PVA nanofibers and their utilization as flexible shielding materials for nuclear fusion reactors as well as for personal protection against neutron radiation. The lightweight and flexible nanofiber mats were formed by electrospinning of a solution of PVA polymer with amorphous boron particles. It has been observed that as the weight ratio of the boron particles is increased, the neutron shielding properties also increase. In addition, fiber formability of solutions, fiber networking structure, and fiber sizes in the mat were found to have effects on neutron shielding capabilities. In recent years, it is of interest to produce radiation shielding materials for special applications such as nuclear energy production, nuclear medicine, and aerospace applications, at low cost, as the use of nuclear energy is increasing in demand. The production of lightweight and flexible shielding materials is particularly proven to be important for ease of production and use. Within our knowledge, the production of lightweight and highly neutron absorbent fiber‐based materials containing boron‐doped PVA nanofibers is reported for the first time in the literature. Hence, we believe that this paper will be of interest to a wide audience of the International Journal of Energy Research.