In this study, 5, 10, and 15 wt% colemanite (Ca₂B₆O₁₁‐5H₂O) and 15 wt% Bi₂O₃ filled high‐density polyethylene (HDPE) composites were fabricated by conventional melt extrusion processing techniques in the form of a layered structure to absorb both neutron radiation and secondary radiation resulting from neutron‐induced reactions. In the layered structure, HDPE was used to slow down neutrons, while colemanite and Bi₂O₃ were used to trap thermal neutrons and secondary gamma radiation respectively. The properties of the colemanite/HDPE and Bi₂O₃/HDPE composites were investigated by scanning electron microscopy (SEM), x‐ray diffraction (XRD), and thermogravimetric analysis (TGA). The mechanical properties (tensile and hardness) of the composites were also investigated. The results showed that the addition of colemanite and Bi₂O₃ particles did not significantly alter the thermal and mechanical properties of the HDPE composites. The total macroscopic cross‐section of the composites was determined using a ²³⁹Pu‐Be (α,n) neutron source, while their linear and mass attenuation coefficients were determined using a ¹³⁷Cs gamma‐ray source. The material with the best neutron absorption rate is 15 wt% colemanite‐filled HDPE (2.31 ± 003 cm⁻¹), while the best gamma‐absorbing material is 15 wt% Bi₂O₃ filled HDPE (0.114 cm⁻¹). The 15 wt% colemanite, 15 wt% Bi₂O₃ doped HDPE layered structure has 1.72 ± 0.05 cm⁻¹ macroscopic cross‐sections and 0.098 linear attenuation coefficient. The results show that filled colemanite HDPE composites improve neutron shielding properties and Bi₂O₃ filled HDPE composites provide good shielding performance for gamma rays.

Middle East Technical University – Defocusing Beam Line (METU-DBL) project is an irradiation facility providing 15 MeV to 30 MeV kinetic energy protons for testing various high radiation level applications, ranging from Hi-Lumi LHC upgrade, space electronic components to nuclear material research. The project located inside the premises of the TAEA (Turkish Atomic Energy Agency) SANAEM (Saraykoy Nuclear Education and Research Center) close to Ankara, provides users a wide selectable flux menu (10⁵–10¹⁰ p/cm²/s). The facility is now being commissioned and the facility will be providing a large test area (20 cm x 15 cm) for material, detector and electronics tests. The proton beam is monitored along the beamline using aluminum oxide screens and the flux and uniformity is measured using three detectors attached to the robotic system for cross- checks. A fiber scintillator detector scans the large irradiation area while small area diamond detector and Timepix3 detector are used for spot checks for calibration. Several samples can be radiated simultaneously inside the irradiation area and the robotic system provides 5 separate holders for samples which can be moved in or out, providing users flexibility for the desired fluence. This talk will first introduce METU- DBL as a radiation test facility, then discuss the radiation monitoring of the beam area and the radiation room, while highlighting how this facility can be used for future testing of materials for radiation tolerance.

In the present study, the radioactivity levels of water samples collected from the main water supply network in Trabzon province and districts and soil samples taken from the vicinity of the water network were measured. An Alphaguard-PQ2000 radon gas detector was used to determine the seasonal radon gas level in the water samples. An HPGe detector was used to determine the level of radioactivity in soil and water samples. The average concentration of ²²²Rn in drinking water ranges from 0.56 ± 0.51 to 13.3 ± 5 Bq L^–1. In water samples, average gross alpha and gross beta values were measured as 8 ± 1 and 43 ± 1 mBq L^–1, respectively. The average concentrations of ²³⁸U, ²³²Th, ¹³⁷Cs, ⁴⁰K radionuclides in soil were measured as 51 ± 2, 21 ± 2, 16 ± 1, 28 ± 7 Bq m^–3, respectively. The average concentrations of ²³⁸U, ²³²Th, ¹³⁷Cs, ⁴⁰K radionuclides in drinking water were measured as 147 ± 5, 25 ± 2, 77 ± 2, 12 ± 2 mBq L^–1, respectively. When the radon concentrations for drinking water were examined, it was found that the radon concentration of the three samples was above the limit value (11 Bq L^–1) allowed by the US-EPA for drinking water. All other results are below the limit values.

Neutron shielding is of utmost importance in radiation environments such as nuclear reactors and particle accelerators and in fields such as health physics. In this work, the percentages of neutrons stopped by shields comprising of boron minerals (HDPE/B2O3, Epoxy/Priceite, Epoxy/Colemanite, Epoxy/Kernite) in their composition against neutron radiation of different energies is investigated using two separate MC simulations. Different layer combinations of epoxy based borated shielding materials with HDPE sheets were then simulated to find the optimum shielding configuration. In addition, radioactivation studies were carried out for these designs. The most suitable design was found to be the layered setup of the HDPE sheet and the epoxy/colemanite composite sheet for mixed neutron energies (

The aim of this study was to evaluate the artificial and natural radiation dose levels in the coastal areas of Trabzon–Rize–Artvin provinces 38 years after the Chernobyl nuclear accident. Radioactive ²³²Th, ²³⁸U, ⁴⁰K and ¹³⁷Cs concentrations were determined in 49 soil samples by HPGe gamma spectrometry. Average concentrations were 12 Bqkg⁻¹ for ²³⁸U, 15 Bqkg⁻¹ for ²³²Th, 162 Bqkg⁻¹ for ⁴⁰K and 37 Bqkg⁻¹ for ¹³⁷Cs. Annual effective dose equivalents and excess lifetime cancer risk values are below the world average. This study also presents the average ¹³⁷Cs value measured in the same area from 1990–2004–2024.