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[en] A survey of the current research programs for CVD coating of fibers designed for reinforcement showed that the coatings are currently designed on the basis of experiments and experience and without the assistance of analytical and numerical simulations of the process. This paper describes studies reported in the literature on modeling a fiber coating reactor, which can be used in the design of fiber-coating process. The need of a comprehensive model for the fiber-coating process, which would consider the entrance effect, reaction kinetics, fluid mechanics, and heat transfer is emphasized. It is suggested that the capabilities of some of the conventional CVD models can be applied to fiber coating reactors. 11 refs

[en] Decomposition of fatty acid hydroperoxide is found to be proportional to the radiation dose. A dose of 20 kGy was found to decompose the hydroperoxide by 98%. Addition of phenolic antioxidants at 4.5 mM could not prevent the decomposition at 20 kGy but the phenolic antioxidants at 20 mM prevented the decomposition. (author)

[en] Sm₂Co_14.75Fe_1.5Ti_0.75 nano-flakes have been prepared by surfactant-assisted ball milling (SABM) in the organic solvent of heptane with the surfactants of oleic acid. The effects of ball milling time on phase composition and magnetic properties were systematically studied. The experimental results show that the synthesized nano-flakes have an amorphous phase and a hexagonal 2:17-type crystalline phase with [001] in-plane crystallographic texture induced by SABM without any external magnetic field. The coercivity value of the as-prepared nano-flakes was 5.0 kOe and then was enhanced to 6.0 kOe by the magnetic alignment for the sample ball-milled for 4 h. The remanence value of the un-aligned nano-flakes is lower than that of the magnetically aligned ones. In addition, the magnetically aligned nano-flakes exhibit a maximum energy product (BH) max of 56 kJ/m³ and a small misalignment angle h of 11°, which is the best value ever reported. The magnetic anisotropy behavior was also observed in both aligned and un-aligned nano-flakes. (author)

[en] The binding energy of _Σ⁴He hypernucleus has been calculated variationally with the (Σ+p+p+n) four-body model. Calculations were done using Monte Carlo technique adopting a Gaussian type potential. The calculated value of the binding energy 3.73 MeV compares well with the experimental value 3.2 _-1.4^0.4 MeV. (author)

[en] Chemical precipitation method for treatment of LLW and ILW by co-precipitation of caesium with nickel ferrocyanide was employed. High decontamination factors were observed in the pH range of 9 to ∼ 11. The percentage removals of ¹³⁷Cs from 37 kBq, 370 kB and 3.4 MBq per litre of simulated effluents were ∼ 90%, 99.7% and 99.8% respectively. Liquid radioactive wastes generated from radioisotope production facilities of AERE, Savar were found to contain ¹³⁴Cs and ⁶⁰Co with the average activity levels of 13.23 kBq/L and 5.3 kBq/L, respectively. Test runs for removal of ¹³⁴Cs from the wastes varied from ∼ 90% to 99%. The radioactive concentrates (sludges) were conditioned by cementation and safely stored in interim storage room. (author). 4 refs, 1 fig., 9 tabs

[en] Studies were carried out on the development and irradiation preservation of semi-dried fish, e.g. Labeo rohita (Ruhi) and Cirrhiuas mrigala (Mrigel), the extension of shelf-life at ambient temperature, and the improvement in the microbiological quality of sealed, ready to eat, commercially prepared fish kebabs by a combination of gamma irradiation with spices and an acidulant such as ascorbic acid. In the processing of semi-dried fish, the combination treatment of a salt dip and irradiation at a dose of 4 kGy extended the shelf-life by more than 3 months. Kebabs prepared in the laboratory and irradiated at a dose of 5 kGy were found to have a shelf-life of up to 6 months at room temperature. With commercially prepared fish kebabs collected from ordinary and sophisticated food shops, the maximum shelf-life extension was 14 days for the 5 kGy treated samples stored at ambient temperature. The microbiological quality of such kebabs indicated that the fish used was of poor quality, resulting in a limited shelf-life, even after chemical and irradiation treatments. Inoculated pack studies of Clostridium botulinum spores showed that when oil fried, the kebab size had a definite effect on heat penetration, and consequent spore reduction. No spores were recovered from the 5 kGy irradiated fried kebabs. (author)

[en] Bangladesh has been operating a 3 MW TRIGA MARK II research reactor since 1986. The reactor was installed in the campus of the Atomic Energy Research Establishment (AERE) at Savar, which is located at about 40 km northwest of Dhaka. It is one of the main nuclear research facilities in the country. The reactor uses TRIGA LEU fuel with uranium content of 20% by weight. The enrichment level of the fuel is 19.7%. The reactor has so far been operated for 4731 hours with a total cumulative burnup (BU) of 8363 MWh (348 MWd). The main areas of use are: training of man-power for nuclear power plant applications, radioisotope (RI) production, neutron activation analysis, neutron radiography and neutron scattering. Radioisotopes produced to date are: I-131, Sc-46 and Tc-99m. The Bangladesh Atomic Energy Commission (BAEC) has been pursuing a project to establish a nuclear power plant (NPP) of 600 MW PWR type in the western zone of the country since the mid 60's. Now, with regard to the safe management, storage and disposal of radioactive waste arising from operation of the research reactor (RR) and also from the proposed NPP expected to be constructed in the future, BAEC has drawn-up short and long-term plans and programs. For addressing safety of radiation sources, protection of man and the environment and in compliance with the Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management, the national NSRC Act (1993) and the NSRC Regulation (1997) are in operation; while the Radioactive Waste and Spent Fuel management Rule-2005 is awaiting approval of the Ministry. It is thought that a once-through fuel cycle and storage followed by either disposal of the spent fuel or returning of some or all of the spent fuels to the country of origin, would be the suitable option for Bangladesh in terms of the management of its spent nuclear fuel from the RR and future NPP. Presently, the TRIGA facility has three Fuel Storage Pits located in the floor of the reactor hall. The pits are made of stainless steel pipes of a diameter 25.4 cm (10 inches) and of depth 457.2 cm (15 feet). Each of the pits is provided with a lock on its stainless steel cover plate to limit access to the pit and also an mild steel cover plate (with lifting hook) that fits flush with the floor. The storage pits were designed to hold 19 TRIGA fuel elements in each pit. For storing the fuel elements into these pits, suitable storage racks would be needed. At present the BAEC reactor facility does not have any rack of such kind. However, efforts have been undertaken to design and develop the storage racks compatible with the storage pits mentioned above and also with the handling and lifting facilities available in the reactor hall. Besides these pits, there are 3 submerged fuel storage racks located along the inner wall of the reactor tank at a depth of about 610 cm (20 feet). Each of the racks is capable of holding 10 fuel elements (total capacity 3 x10 = 30). The purpose of these racks is to provide temporary storage for the fuel-moderator or the graphite dummy elements before their transfer to the fuel storage pits mentioned above. The BAEC reactor facility also needs to have a spent fuel transfer cask for transferring irradiated fuel from the reactor pool to the spent fuel storage pits. BAEC has taken measures to design and develop such cask with the assistance of the IAEA under a TC project being implemented now (2005-2006 cycle) in the reactor facility. Presently, there does not exist any spent fuel element in the reactor facility. However, with the recently undertaken RI production enhancement program, it is expected that the reactor will start generate spent fuels from the year 2012. It is worthwhile to mention that a Central Radioactive Waste Processing and Storage Facility (CWPSE) has been constructed near the research reactor facility in AERE. The activities of this facility include: collection, handling, segregation, characterization, classification, treatment, conditioning, storage and disposal of all kinds of radioactive wastes generated from nuclear installations, and from application of radioactive materials in medicine, industry, research, agriculture, education, etc. BAEC has been working as the competent authority for the Nuclear Safety and Radiation Control in Bangladesh. The legal basis is the 'Nuclear Safety and Radiation Control (NSRC) Act, 1993 and the Nuclear Safety and Radiation Control Rules, 1997' which incorporate the requirements of the International Basic Safety Standards. The Act-1993, Rules-1997, Statutory Regulatory Orders of 1996, 2000 and the Rules-2005 cover all aspects of radiation, waste and transport safety. BAEC is speeding-up the process of becoming a party to the Joint Convention. The paper presents the current strategy for the safe management and disposal of radioactive waste, including Spent Sealed Radiation Sources (SRS), spent fuel, the national policy for the back end of the fuel cycle and anticipated future trends

[en] Under an IAEA model project (INT/4/131:Sustainable Technologies for Managing Radioactive Waste), disused radium sources used as calibrators, applicators and needles were collected, transported, conditioned and stored for the safe management of radioactive wastes used in medical, industrial and research applications in Bangladesh. About one gram of disused known radium sources was collected from various hospitals and nuclear medicine centers as a part of the inventory of radiation sealed sources in the country and transported to the Atomic Energy Research Establishment (AERE) Campus, Savar for conditioning. IAEA transport regulations and Nuclear Safety and Radiation Control Rules (NSRC, Bangladesh) were followed during transportation for the safety and to avoid unwanted radiation exposure. These wastes were conditioned into two 200 L MS drums and safely stored in an isolated interim storage room in the AERE campus, Savar under the auspices and help of the International Atomic Energy Agency expertise. This paper describes the inventory, transportation, conditioning, storage and radiation monitoring as well for the safe management of disused ²²⁶Ra sources in Bangladesh. (author)

[en] In Bangladesh, LILW radioactive wastes are generated from operation and maintenance of nuclear installations: Research Reactor, Radioisotope Production Laboratory, Neutron Generator, hot facilities, application/use of radiation sources (RS) in medicine, research, agriculture, industry. The radioactive wastes arising are described in this paper. The national policy concerning radioactive wastes and the activities being performed by the Health Physics and Radioactive Waste Management Unit of AERE, Savar, are outlined. BAEC has a perspective plan (2001-2010) to establish a pilot-scale near-surface waste repository for short-lived LILW. The factors being studied are presented, covering: general site description within the AERE campus; geology, hydrology and rivers; seismicity; surface drainage and ground water table; climate and meteorology; transportation and communication; demography and nearby facilities; vegetation; water and power supply; background radiation, nearest township; natural environment, land and water usage; dispersion of radioactive materials through groundwater; engineered feature. (author)