Waleed H. Abulfaraj

Thermoluminscence of irradiated herbs and spices

Abstract Several types of herbs and spices from the local market were irradiated with different doses of γ radiations. Doses varied from a few kilograys to 10 kilograys. Thermoluminescence of the irradiated samples and their controls was investigated. For the same type of herb or spice glow curves of different magnitudes, corresponding somewhat to the doses given, were obtained from the irradiated samples. Most control samples gave little or insignificant glow. Glow curves from different herbs and spices irradiated with the same doses were not similar in the strength of the glow signal given. Samples of the black pepper obtained from different packages sometimes give glow curves of very different intensities. Samples from irradiated black pepper were found to show little fading of their glow curves even at 9 months postirradiation. All irradiations were done under the same experimental conditions and at a dose rate of approximately 1 kGy h -1 . The glow curves were obtained using a heating rate of about 9°C s -1 and a constant nitrogen flow rate.

Measurements of hair lead concentrations in children of four cities in Saudi Arabia

Abstract The concentrations of lead in the scalp hair of 800 school children, aged 6–8 years, from four cities: Makkah, Jeddah, Riyadh and Tabuk in Saudi Arabia, were measured by Electrothermal Atomic Absorption Spectrometry. Mean lead concentrations for these four locations were found to be 17.6 μg Pb/g hair for Makkah, 23.3 μg Pb/g hair for Jeddah, 5.1 μg Pb/g hair for Riyadh and 10.9 μg Pb/g hair for Tabuk. The mean values of Pb concentrations in hair for Jeddah, Makkah and Tabuk cities are on the high side of the acceptable ‘normal range,’ indicating an increasing trend in environmental lead pollution. Riyadh appears to be relatively ‘clean’ in this respect. Rapid modernization with increased use of leaded gasoline for transportation may already be causing a stress on the environment of Saudi Arabia.

Measurement of ambient air lead concentrations in the city of Jeddah, Saudi Arabia

Lead concentrations were determined in six different locations in the Jeddah urban area by atomic absorption spectrometry. Correlations between the air-Pb data and traffic density were investigated. The lead concentration values obtained for the ambient air in Jeddah City ranged from 0.19 {mu}/m{sup 3} to 1.27 {mu}g/m{sup 3}. Comparison with ambient air quality standards from other countries indicates that certain areas in this city are approaching these guideline values.

Radioactivity concentration in soil in Jeddah area, Saudi Arabia

Abstract The level of radioactivity in soil was measured in Jeddah area. 137Cs concentration was determined as an indication of the degree of contamination from Chernobyl accident. Natural uranium and thorium radioactive series, as well as 40K concentration levels have been determined. These radioisotopes contribute to the background exposure both indoor and outdoor. The concentration of 214Bi a member of 238U Series and that of 228Ac from 232Th series were measured. For the gamma spectroscopy method 10% efficiency high purity vertifical Ge detector of 2 KeV resolution at 1.332 Mcv was utilized. Standard soil sources were made using 152Eu and 137Cs of known activities. The concentration of 137Cs, 214Bi, 228Ac and 40K in Bq/Kg were 0.32, 9,25, 7.4 and 369 respectively. The energy dependent Ge detector efficiency for measuring radioactivity in soil was further determined.

Siting of Nuclear Power Plants in Saudi Arabia Using Fuzzy Decision Analysis

Fuzzy set theory is adapted here to handle decisions on selection of sites for nuclear power plants. The approach is demonstrated by considering a choice of a site for the first nuclear power plant in Saudi Arabia. The approach allows for accommodation of imprecision in evaluation of the factors impacting site selection such as the site geology; hydrology; seismology; topography; meteorology; and availability of cooling water, services, and transportation. Based on the criteria used, preference of the East Coast site over the West Coast site is found within the fuzzy environment surrounding the decision. The approach is quite adequate in situations where precise data are not available and when the decision maker prefers to resort to verbal ratings rather than to use the tedious course of sensitivity analysis. The alternate sites under consideration, however, must meet at least a minimum level of acceptance from the nuclear safety point of view.

Decontamination leaching of Ra-226 contaminated gravel as monitored by liquid scintillation counting and thermoluminescent dosimetry

This article concerns with the decontamination of gravel that had been contaminated with Ra-226 from natural origins.

Optimization of LS counting parameters for measurement of low levels of 222Rn in water

Abstract Potential health hazards are associated with continued use of 222 Rn rich water for drinking. Since high concentrations of 222 Rn frequently occur in some well waters, it becomes important to analyze well waters that may be used for drinking, for its 222 Rn concentrations. In view of the large number of water samples that may need to be analyzed and because of the relatively short half life of 222 Rn, a rapid and sensitive counting method for measuring 222 Rn in well waters should be useful. Such a method was achieved by optimization of some of the scintillation counting parameters including, type of fluor used, water/fluor ratio and width of the counting window used.

Design of a temporary radioactive waste storage facility

Abstract The impact of radioactive waste in King Abdulaziz University has given rise to the need for a temporary radioactive waste storage made of reinforced concrete (R.C.). In the framework of more recent ICRP recommendations and IAEA technical guidelines, the radiation protection requirements and the applicability of low level radioactive waste management have been suggested. The design and performance have been analyzed through civil engineering inspections and shielding calculations for any corrective actions. This paper specifies the radiation protection criteria for a storage facility and for the management of low level radioactive waste (LLRW).

Special concrete shield selection using the analytic hierarchy process

Special types of concrete radiation shields that depend on locally available materials and have improved properties for both neutron and gamma-ray attenuation were developed by using plastic materials and heavy ores. The analytic hierarchy process (AHP) is implemented to evaluate these types for selecting the best biological radiation shield for nuclear reactors. Factors affecting the selection decision are degree of protection against neutrons, degree of protection against gamma rays, suitability of the concrete as building material, and economic considerations. The seven concrete alternatives are barite-polyethylene concrete, barite-polyvinyl chloride (PVC) concrete, barite-portland cement concrete, pyrite-polyethylene concrete, pyrite-PVC concrete, pyrite-portland cement concrete, and ordinary concrete. The AHP analysis shows the superiority of pyrite-polyethylene concrete over the others.

Radiation dose assessment from ingestion pathway in Saudi Arabia

Abstract Levels of radioactivities in foodstuffs in the local market have been measured for the period from November 1987 until end of June 1988. Out of the 674 samples analyzed there were 83 milk powder, 85 infant milk powder, 54 infant cereals, 89 meat, 16 lentils, 14 wheat, and 26 macaroni samples. The average radioactivity concentration of 137Cs and 134Cs, in these samples in Bq/kg were 19, 13, 18, 6, 10, 25 and 13 respectively. The rest adults and infant foodstuffs had negligible radioactivity levels. The calculated annual doses from ingestion pathway due to 137Cs and 134Cs for adults were 3.13 × 10−5 Sv and 2.1 × 10−5 Sv while for one year old infant they were 12 ×10−5 Sv and 8 × 10−5 Sv respectively. The estimated accumulated dose for 50 years from 90Sr due to one year food ingestion for adults and one year old infants were 3.76 × 10−5 Sv and 5.2 × 10−5 Sv respectively.