The effect of sample density in the determination of radionuclides by gamma spectrometry was studied using two multinuclide standard sources of different densities. The self absorption corrections due to differences in sample matrix densities were estimated. The corrections were used in the analysis food and soil samples having packing densities between 0.2 – 1.6g/ml.
The purpose of this study was to determine the adsorption coefficient (Koc) of chlorpyrifos in clay soil by measuring the Freundlich adsorption coefficient (Kads(f)) and desorption coefficient (1/n value) of chlorpyrifos. It was found that the Freundlich adsorption coefficient (Kads(f)) and the linear regression (r 2 ) of the Freundlich adsorption isotherm for chlorpyrifos in the clay soil were 52.6 L/kg and 0.5344, respectively. Adsoprtion equilibrium time was achieved within 24 hours for clay soil. This adsoprtion equilibrium time was used to determine the effect of concentration on adsorption. The adsorption coefficient (Koc) of clay soil was found to be 2783 L/kg with an initial concentration solution of 1 µg/g, soil-solution ratio (1:5) at 30 o C when the equilibrium between the soil matrix and solution was 24 hours. The Kdes decreased over four repetitions of the desorption process. The chlorpyrifos residues may be strongly adsorbed onto the surface of clay.
Analyses activities of 226 Ra and 228 Ra were conducted at ten stations of Pulau Redang, Malaysia. Dissolved radium isotopes such as 226 Ra and 228 Ra had shown enrichment at coastal area stations. Meanwhile, activities of both nuclides in the suspended particle matters were slightly in equilibrium with the activity ratio ranging from 0.88 – 1.86. The calculated distribution coefficient values (Kd) of 226 Ra and 228 Ra were in the range of 0.78 x 10 5 L g -1 to 5.56 x 10 5 L g -1 and 0.21 x 10 5 L g -1 to 1.86 x 10 5 L g -1 , respectively, indicate that most of the radium nuclides in the study area are strongly absorbed into the particulate phases. Therefore, low concentrations of suspended particles matter in the water column (< 10 mg L -1 ) have insignificant effects on the Kd values.
Gamma Spectrometry Counting System requires similar counting geometries for the calibration source, reference material and samples. The objectives of this study were to find out the effects of the sample density on 137 Cs activities measurement and propose reasonable corrections. Studies found that the activity of the samples is decreasing when the density of samples increased. Therefore, in order to have a more accurate estimation of samples activities; density corrections should be done either by performs mathematical corrections using equation or by increasing the expanded uncertainty when sample densities deviated from calibration source.
Atmospheric Pollution due to airborne particle is a major concern to many cities in the Southeast Asian region, including Kuala Lumpur. Within the last six years air particulate samples have been collected from a site in Kuala Lumpur and measured for their PM10, PM2.5 and elemental concentrations. The results showed that the daily PM10 (
Developments of computer technology and image processing have shifted conventional industrial radiography application to industrial digital radiography (IDR) system. In this study, two types of IDR modules for non destructive testing (NDT), namely drum- and laser- type film digitizer with 50 μm pixel pitch have been evaluated for NDT applications. The modulation transfer function (MTF) and noise power spectrum (NPS) measurement were adapted to evaluate the image quality of IDR images. Results shown the averaged MTF for drum- and laser- type film digitizer at 20% modulation were 6.15 cycles/mm and 6.55 cycles/mm respectively. For NPS measurement and calculation, the result obtained shows that drum type film digitizer produced higher noise then laser type film digitizer. The study shows that the laser type film digitizer is the best system to be used for film digitization purposes because the MTF result shows that it modulates better than drum type and has the lowest and stable NPS.
The temperature profile of a cryogenic system for cooling of beryllium filter of a small-angle neutron scattering (SANS) instrument of TRIGA MARK II PUSPATI research reactor was investigated using computational fluid dynamics (CFD) modeling and simulation. The efficient cooling of beryllium filter is important for obtaining higher cold neutron transmission for the SANS instrument. This paper presents the transient CFD results of temperature distributions via the thermal link to the beryllium and simulation of heat
flux. The temperature simulation data are also compared with the experimental results for the cooling time and distribution to the beryllium.
Ageing management is one of the important safety factors to be implemented proactively throughout the lifetime of a research reactor. In order to continue the safe operation of a research reactor from the reactor safety standpoint, a systematic and methodical approach should be taken. In practice, ageing management programme is accomplished by integrating the existing programmes including maintenance, periodic testing and inspection and periodic safety reviews. Such approach will be a good platform for the reactor operation
and maintenance group to utilize data from existing maintenance programme to be incorporate into the ageing maintenance system. This paper will describe the ageing management programme for Reactor TRIGA PUSPATI (RTP).
The paper relates a study on the development of an analysis procedure for measuring the gold coating thickness using EDXRF technique. Gold coating thickness was measured by relating the counts under the Au Lα peak its thickness value. In order to get a reasonably accurate result, a calibration graph was plotted using five gold-coated reference standards of different thicknesses. The calibration graph shows a straight line for thin coating measurement until 0.9μm. Beyond this the relationship was not linear and this may be resulted from the selfabsorption effect. Quantitative analysis was also performed on two different samples of goldcoated jewelry and a phone connector. Result from the phone connector analysis seems to agree with the manufacturer’s gold coating value. From the analysis of gold-coated jewelry it had been able to differentiate the two articles as gold wash and gold electroplated.
To quantify the effectiveness of deuterons and helium particles at low doses, the inactivation rate in
vitro for V79 cells has been extracted from radiobiological published data. The Physical parameters
characteristics of these charged particles such as the linear energy transfer, the restricted linear
energy transfer, the linear primary ionization and the mean free path are determined. The
relationship between the inactivation rate and the physical parameters for deuterons and heluim-3
particles has been established in this research. This approach enables in getting the distinctive
biological response in terms of varies physical quality parameters. The best statistical regression
fittings are formulated for each correlation.
In the an electron-proton collider, neutral hadrons were produced in the hadronisation process that
occurred just after the electron-proton collision. The neutral hadrons were produced at interaction
point using reference energy from its centre-of-mass. In this paper, we discuss the kinematics of
particles produced from its centre-of-mass and the hadronisation process follows after such collision.
In order to prepare Malaysia to be nuclear ready, the Malaysian 1 MW TRIGA MARK II research
reactor (RTP) located at the Malaysian Nuclear Agency was premeditated with the aim to effectually
actualize the multitude areas of basic nuclear research, labor training and education. To meet the
modern safety standards, analyses of a strong interaction between the thermal-hydraulic system
behavior and the space-dependent neutron kinetics are needed as mere thermal-hydraulics codes are
said to be incapable to succeed the present safety standards. This could be achieved through the
coupling of neutronic and thermal-hydraulic codes of the reactor. Previous studies had shown that the
coupled codes are able to successfully be employed for the correlation between thermal-hydraulic
analysis and neutron kinetics at transient and steady state. In this study, the coupling was achieved
through MCNP and TRIGLAV codes for neutronic and thermal-hydraulic respectively. Core-15 of
RTP was modeled for both of the codes; hence calculating the criticality, analysis of power and
neutron flux distribution. The consistency and accuracy of the developed Core-15 MCNP model was
established by comparing calculations to the experimental results and TRIGLAV code. The criticality
predictions for both codes are in very good agreement with the experimental results. The core reached
its criticality after 66 fuels. The highest hot rod power peaking factor was found to be 1.28. The
results are conservative and can be applied to show the reliability of MCNP and TRIGLAV codes.
This work main aim is to study the analysis of slow neutrons which include thermal and
epithermal neutrons and also analysis on fast neutrons. The outcome from this work showed that
the comparison result between fast and slow neutrons. The safety assessment at reactor TRIGA
FUSFATI (RTF) is one of the main objectives of the work and there is a detailed discussion on it
which helped in accomplishing the task. Gamma Rays produced in this experiment was high and in
the experiment and it is realized that the shielding plays a vital role in the success of this
experiment which prevents all the radiations. From the results of the experiment it is realized that
these gamma rays are not suitable for the application of Boron Neutron Capture Therapy
(BNCT). However, these radiations are suitable for the application of Neutron Radiography (NR).
The study on this work will help in study of nuclear applications such as BNCT, NR, SANS etc.
These applications are using in medical and nuclear fields. The electronic device used in the
experiment to detect neutron is Neutron Spectrometer. The results from Neutron Spectrometer
and TLDs are very similar which showed that the experiment is a success. Numerical results were
compared with those available in literature for validation.
There is a growing interest from, newcomer countries to utilise nuclear energy for electricity
generation. The International Atomic. Energy Agency (IAEA) has developed two methodologies,
namely, the IAEA Milestone Approach and the International Project on Innovative Nuclear Reactors
and Fuel Cycles (INPRO) Methodology to help its Member States in assessing the viability of nuclear
power programme (NPP) and nuclear energy system. This paper highlights important features of both
methodologies in supporting deployment of nuclear power programme for a newcomer country. In
summary, the IAEA Milestone Approach focuses for near term while the INPRO Methodology focuses
for long term assessment to support the deployment of first NPP in newcomer countries. Depending
on newcomer country's priority and resources, both methodologies can be performed either separately
or in-parallel.
One of the major component in neutron radiography is a collimator that is used to collimate the neutron in parallel beam with less gamma ray contamination and high thermal neutron flux. The collimator consists of seven components and the interest component is an aperture as it is used to prevent the thermal neutron from entering the beam except through the center hole. In this study, the collimator design was taken from radial beam port at NR facilities at ANM with the collimation ratio is 46.4. In order to increase the collimation ratio, optimization of the aperture component has been done on four different material and 1-5 cm diameter parameters. The optimization of apertures shows that the cadmium with 1 cm diameter yields the thermal neutron flux at the collimator inlet and outlet with 1.78 x103 n cm-2 s-1 and 5.90 x102 n cm-2 s-1 while the gamma ray contamination was 10.7 μSv hr-1. The optimization succeed to produce high L/D ratio however the thermal flux was low and the gamma contamination was higher that original design but satisfied the ICRP 74 condition for radiation worker.
Structural and dielectric properties of barium strontium, titanate (Ba(ÿ)SrxTiO$) ceramics with x—
0.25, 0.5 and 0.75 were investigated. The Ba(i-xjSrxTiOs ceramics were synthesised by solid state
reaction method. Microstructure, surface morphology and dielectric properties of the synthesised
ceramics were examined using XRD, SEM and Impedance Spectroscopy respectively. XRD results
revealed that all samples contained BaTiOg as primary phase with tetragonal perovskite crystal
structure. The crystallite size slightly increased with the increasing of Sr contents. SEM micrographs
showed that the microstructure become denser when Sr contents increased. Impedance spectroscopy
showed dielectric constant for all samples were decreased with increasing temperature up to 200°C.
This study focused, on the activity concentration and radiation hazard assessment of radionuclide in
bricks. The activity concentrations per unit of mass in the studied bricks ranged from 59.82 to 236.65
Bqkg'1 for Ra-226, from 66.29 to 185-4 Bqkg'1 for Th-232, and from 283.50 to 1599.67 Bqkg'1for K-fO.
In terms of radiation hazard assessment, granite bricks exceeded the allowance limit stated by Nuclear
Energy Agency -Organisation for Economic Co-operation & Development (NEA-OECD) in radiumequilibrium
activity (Req), External Hazard Index (Hex), Internal Hazard Index (Hin) and
Representative Level Index (Iw). Thus, this has proof that the naturally occurring radionuclide
materials present in the brick have a potential in effecting the dwellers health.
Thermoplastic natural rubber sample is found isotropic based on Small Angle X-Ray Scattering (SAXS) pattern. Morphological interpretation was deduced based on ideal lamellar morphology using 1-D correlation function. The fitting was carried out using Porod tail model and Vonk for backextrapolated model. It is found that the long period value is 15. 7nm which is comparable to results obtained from Lorenzt corrected profile, 20nm. Crystalline thickness and amorphous thickness was found as 13.4 and 2.31nm respectively.
Electricity has become one of the necessities for human daily activities. The presence of electric
current produces electromagnetic fields (EMF) at extremely low frequency (ELF). The problem arises
when scientists suggests a possible connection between ELF exposure to human health and safety.
Concerned about the safety and health of students and staff, Universiti Kebangsaan Malaysia (UKM)
took the initiative to identify possible ELF sources and measure their exposure in various locations
around the UKM main campus in Bangi. This paper reports the results obtained from the monitoring
of the magnetic flux density at three identified locations in the vicinity of the overhead high-voltage
transmission line which transverses the university compound and compare the maximum value results
with the exposure limit suggested by the International Committee on Non Ionising Radiation
Protection (ICNIRP) for ELF. Measurements were done with an (Extech) Three Axis
Electromagnetic Field (EMF) Meter (Model 430826) to determine the magnetic flux density. The
lateral profile method was applied as the standard measurement methodology. Results showed that the
maximum value of the magnetic flux density was 12.5 mG, which is below the suggested ICNIRP
public exposure limit of 1000 mG, or in percentage ratio, 1.25% of ICNIRP public exposure limit.
Results from the statistical Kruskal-Wallis test showed that there is a significant difference in the
distributions of the magnetic flux densities at the different locations (P < 0.05). In conclusion, the
measured locations are still safe for people in short-term exposure. However, long-term exposure
measurements still need to be done to provide concrete data on the ELF-emission levels in UKM.
Thorium is a fertile material that can undergo transmutation for it to become a fissile material,
uranium-233. The fissile material can go through a fission process in order to generate heat energy
and eventually electricity. Most nuclear reactors use uranium as their fission source. The use of
thorium as nuclear fuel has been only investigated for few types of reactors such as a high, temperature
gas reactor (HTGR), fast breeder reactor, light water reactor (LWR) and heavy water reactor
(HWR). For research reactors specifically, there are limited academic publications related to the
la,test u.se of thorium. Hence, the main, interest, of this work is to compile and review the latest
academic publications related to the active use of thorium, for research reactors in particular. The
reviewed studies have been, divided into two categories which are experimented and simulation projects.
The experimental projects are a,bold the ongoing thorium fuel tests that have been carried out. in an
actual, research reactor. On the hand, the simulation work: is related to the computational analysis
performed in predicting the neutronic behaviour of thorium based fuel in research reactors. The
experimented study of thorium is currently active for the KAMINI research reactor. Additionally, most,
simulation works focus on finding criticality and neutron spectra.