[en] Recent development of neutron imaging technique from the view point of phase-information as well as stroboscopic applications is presented. The pin-hole collimator of the diameter of about 0.4 mm was used to obtain neutron beam of the wavelength of 0.443 nm with divergence angle of 6 mrad and the sample was set at 1.8 m apart so that the neutron plane wave approximation hold. The detection just behind the sample provides conventional neutron images while the detection set at the distance of 1.8 m from the sample provides phase contrast images. Thus, the sample edge is accentuated as the plane wave is disturbed there. Cold neutron beams were used to obtain very clear images of fiber reinforced plastics, gas turbine blades, and welded part of aluminum alloy. Furthermore, the rotary engine of 300-3000 rpm was imaged from its repeated motion by stroboscopic technique using pulsed neutron beams with time resolution of 0.2-2 msec. Finally, the combined images was obtained from X-ray imaging which is obtained by attenuation measurement of transmitted neutron beam together from neutron imaging which is obtained by phase information of neutron beam after interaction with the sample. (S. Ohno)

[en] The radiation-induced decolouration and degradation of aqueous solutions of azo dyes and their model compounds (anilines, phenols, triazines) are reviewed together with practical applications and the experimental methods (pulse radiolysis, steady-state gamma radiolysis, as well as end-product analysis) used for studying the reactions. The proposed mechanisms and the rate coefficients for the reactions of ^·OH, e_aq^- and ^·H water radiolysis intermediates with the dye molecules and with model compounds are summarized

[en] The gamma-gamma coincidence counting method with two coaxial Ge detectors was applied to the absolute measurement of radioactivity. To investigate the dependence of the calculated activity on the coincidence time, a ⁶⁰Co standard point source was measured by a gamma-gamma coincidence counting system. As a result, it was confirmed that the coincidence time did not influence the calculated activity, which agreed with the calibrated value within 10%. To estimate measurable range of source disposition, two or nine ⁶⁰Co sources were measured by this system. As a result, the measurable range was 3 cm x 10 cm x 10 cm (thickness x width x height), when the detector-detector distance was 10 cm. (author)

[en] Unreported tantalum isomer ^186mTa has been produced through the reaction ¹⁸⁶W(n,p) by irradiation of ^natW with 14 MeV neutrons. The activity of ^186mTa and ¹⁸⁶Ta was measured using HPGe detectors and several X-γ as well as γ-γ coincidence arrangements. The ^186mTa has been identified by means of measuring known γ rays from ¹⁸⁶Ta β-decay. The half-life of ^186mTa has been determined to be (1.5±0.1) min. (authors)

[en] This study indicates that Gamma irradiation could be the solution for raising the standards of disinfection in waste water of Damascus city up to the international standards, when samples of the inlet of the planet was irradiated with Gamma radiation at dose rate of 3.4 KGy./hr The radiation sensitivity of total micro-organisms, fungi, and pathogenic bacteria was 0.316, 0.318 , 0.306 KGy respectively Also the results showed the absence of Ascaris Lumbricoides ova which permit reusing the recycled waste water in irrigation safely. (authors)

[en] Intercomparison is an important tool for quality assessment, since not only the equipment performance but also the procedures are evaluated and compared. This tool is wide utilized to evaluate the ability of nuclear medicine services (NMS) to measure activities of radiopharmaceuticals. Since 1998, the Laboratorio Nacional de Metrologia das Radiacoes Ionizantes (LNMRI/IRD/CNEN) has been conducting intercomparison programs at Rio de Janeiro and surroundings, and, after successive rounds of comparison, an improvement in the performance of the radionuclide calibrators have been observed in this region. Similar results were observed worldwide. The Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN) was designated by the LNMRI to establish the intercomparison program of activity measurements in NMS in the Brazilian northeast. The aim of this work is to present the results of the first round of comparison measurements of activity of ^99mTc and ¹³¹I. This round was carried out in Recife/PE. Six NMS participated in this intercomparison. Additionally to the activity measurement, some information about equipment (calibration and quality control program) and human resources was obtained. All NMS participants complied with the limit established by CNEN for the accuracy of measurement (±10%) for ⁹⁹mTc and ¹³¹I. Measurements will be repeated for ^99mTc and ¹³¹I, and additional rounds will be performed including different radionuclides. (author)

[en] In order to develop a water treatment programme following points must be kept in mind: Effectiveness to achieve desired water quality objectives; Compliance with regulatory requirements; Cost minimization; Safety; Easy operation and protection to equipments. Heavy Water Plant (Manuguru) laboratory has developed treatment programs to treat raw water and cooling water which satisfy the above requirements and has been in use for last several years successfully without any problem. These treatment programs have been given to other plants in Heavy Water Board for implementation. This paper describes the chemistry of the treatment program and cost minimization achieved. Further these treatments have helped the plant in achieving ΦZero Discharge and indirectly reduced the production cost. The chemistry parameters are monitored regularly to ascertain the effectiveness of these treatments. The areas where significant benefits derived are raw water treatment using polyelectrolyte instead of inorganic coagulant (alum), change over of regenerant of cation exchangers from hydrochloric acid to sulfuric acid and development of in-house cooling water treatment formulation. The advantages and cost effectiveness of these treatments are discussed in detail. Further these treatments helped the plant in achieving Zero discharge and indirectly reduced production cost of heavy water. The dosage of 3 ppm of polyelectrolyte can replace 90 ppm alum at turbidity level of 300 NTU of raw water which has resulted in cost saving of Rs. 15 - 20 Lakhs in a year besides other advantages. The changeover of regenerant from HCl to H₂SO₄ will result in cost saving of at least Rs. 1.4 Crore a year along with other advantages. The change over of proprietary formulation to in-house formulation in cooling water treatment has resulted a saving about Rs. 11 Lakhs a year. To achieve the above objectives in a sustainable way the performance results are being monitored (author)

[en] Water is a precious gift of nature to the mankind and it is vital for living beings and industries. It may become a scarce resource, if proper measures are not adopted timely to conserve the same. Water Management with measures taken for water, energy conservation and effluent reduction at HWP - Hazira are described in the present paper. System details of pre-treatment, cooling water, steam, boiler, effluent etc. pertaining to HWP-Hazira are described. Cooling water treatment adopted in HWP-HAZIRA is operating at 3-4 concentration cycles. Treatment is found to be satisfactory as revealed by the absence of scaling or corrosion induced by microbial fouling in coolers, heat exchangers etc. due to observations made during the last ATR. The cooling water treatment adopted and followed by KRIBHCO is also described. KRIBHCO is operating their cooling water system at a cycle of concentration of 7-8 to conserve water and chemicals. (author)

[en] This paper describes the role of MDS Nordion and AECL in ensuring a reliable global supply of medical isotopes. The First part of the paper discusses the uses of medical isotopes, their importance to the medical community, and the benefits to patients of a secure supply of medical isotopes. The second part describes the role of the NRU reactor and the future role of the MAPLE reactors and New Processing Facility being commissioned at AECL's Chalk River Laboratories for production of medical isotopes to meet the world market demand for the next 40 years. MDS Nordion is the world's leading supplier of medical isotopes. These isotopes are used to conduct some 34,000 nuclear medicine procedures performed every day around the world, such as determining the severity of heart disease, the spread of cancer, and diagnosing brain disorders. These medical isotopes are currently produced primarily by AECL in the NRU reactor at Chalk River, Ontario, Canada. (author)

[en] The neutron field, referred to as the standard or reference neutron field, is essentially necessary for calibration of detectors, cross-section measurements, neutron dosimetry and so on. At High Energy Accelerator Research Organization (KEK), reference thermal neutron field has been established inside-and outside of the graphite pile (250 x 190 x 190 cm³) since 2000, and has been utilized for the calibration of neutron rem-counters, thermal neutron detectors such as ³He counter, TLD elements and so on. In this paper we would propose, as a method for absolute calibration of radioactive neutron source strength, to perform the spatial integration of thermal neutron flux inside-and on surface of the graphite pile (hereafter, we call a graphite-bath method). Hitherto the MnSO₄-bath method has been generally utilized as the standard for absolute measurements of neutron source strength in many national standards laboratories including Advance Industrial Science and Technology (AIST) of Japan. However, the Mn-bath technique has a few troublesome problems including the maintenance and surveillance of purity or concentration in MnSO₄ solution and furthermore the absolute measurement of induced ⁵⁶Mn activities with rather complex decay scheme. We will describe below the principle and procedures of graphite-bath method and the results obtained by this method for two kinds of neutron sources, i.e, ²⁴¹Am-Be and ²⁵²Cf; the former was previously calibrated based on the relative comparison with AIST standard source. (author)