Dose Calculation and Measurement from B¹⁰(n, α)Li⁷ Reaction Using Filtered Neutron Beam at Nuclear Research Institute

In this research, dose calculation and measurement from B10 (n, α) Li7 reaction usingfiltered neutron beam at the Nuclear Research Institute have been reported. Calculation was carried out by Monte Carlo method using MCNP5 code. Neutron activation technique using vanadium foil was employed to determine neutron flux at various positions in phantom from which neutron dose has been calculated using conversion factor. These calculations are basics for the dose determination research of the Boron Neutron Capture Therapy (BNCT) in Vietnam.

Identifying the Presence of Natural Radionuclides in Ashlar Samples

Humans have always been exposed to different types of natural and cosmic radiation. At present we experience 83 % natural radiation, for example from granite marbles, building materials such as concrete, brick, granite, or drywall. However, although these are potential sources of radon, they are rarely the cause of a high level of pollution in a building.Ashlar is a material of volcanic origin comprising heterogeneous and solidified detrital pyroclastic materials such as rhyolite, sand, volcanic ash and pumice, among others. Chemically, ashlar is principally composed of elements such as sodium, magnesium, calcium, iron, aluminum, sulfur, and cobalt. In order to identify the presence of these elements in the ashlar, X-ray Fluorescence studies were carried out first, using modern XRD and XRF equipment, followed by quantitative analysis using a neutron activation technique, and finally, low-level gamma spectrometry to evaluate the presence of radioactive elements.

Determination of Extractable and Bound Organochlorine in Sediment by Instrumental Neutron Activation Analysis

Extractable organochlorine (EOC) and bound organochlorine (BOC) compositions in sediments from Lake Bosomtwi have been determined with instrumental neutron activation technique. Within the limit of experimental errors, the precision and accuracy of the method for the determination were within 3% and 4% respectively. The mean levels of EOC and BOC were in the range of 1.71 mg/kg to 5.18 mg/kg and 0.31 mg/kg to 0.68 mg/kg respectively. Analysis of organochlorine data showed the EOC content on the average was about seven times more than those of BOC. Washing of chloride from sediment fortified with an insoluble chloride, thus PbCl2, with various concentrations of sodium nitrate (NaNO3) solutions was investigated and washing with 0.1 M solution of NaNO3 gave the optimum yield of chloride. Organic carbon (OC) and BOC compositions in the sediments were subjected to correlation analysis and results showed that the two correlated very well with corrected coefficient of 0.65. OC in sediments could therefore, be one of the carrier phases of BOC in sediments.