[en] Russia plans to accelerate uranium exploration and production activities to guarantee steady development of mining enterprises. The amount and quality of known uranium resources and current production rates cannot provide the planned requirements. The basic directions in uranium production development are development of active mining facilities, revaluation of stand by uranium deposits, uranium joint production in Kazakhstan. To provide effective mining for the next 30 years at Priargunsky center modernization of mining and technological equipment is conducted currently. Two new uranium producing centers Dalur and Khiagda are under construction. Both operate sandstone basal channel deposits using sulfuric acid ISL technology. Large uranium deposits in Aldan district will be studied for high-grade mineralization distribution and effective ore processing. Realization of presented activities on uranium production development must considerably reduce the rates of stocks depletion and provide fuel requirements of the Russian nuclear industry up to 2025-2030. (author)

[en] A mobile melt-dilute (MMD) module for the treatment of aluminum research reactor spent fuel is being developed jointly by the Savannah River National Laboratory and Argonne National Laboratory. The process uses a closed system approach to retain fission products/gases inside a sealed canister after treatment. The MMD process melts and dilutes spent fuel with depleted uranium to obtain an isotopic content of less than 20 percent. The final ingot is solidified inside the sealed canister and can be stored safely either wet or dry until final disposition or reprocessing. The MMD module can be staged at or near the research reactor fuel storage sites to facilitate the melt-dilute treatment of the spent fuel into a stable non-proliferable form

[en] The focus of most industrial activity today is on improving the performance of existing nuclear power reactors and their fuel. These are all important improvements, but in the long term, continued progress will depend on innovative new designs and fuel cycle technologies. To catalyse innovation IAEA supports the development of new reactor and fuel cycle technologies through dissemination of global knowledge, fostering information exchange and coordinated R and D activities

[en] This paper describes a system, which is installed at Nuclear Fuel Complex, Hyderabad. It is a tube rotation fixed probe type of system designed for fully automatic operation at high speed using immersion technique for ultrasonic flaw detection and dimensional measurement of precision of zirconium alloy seamless tubes used in fuel bundles for nuclear reactors

[en] The purpose of this laboratory study is to determine the influence of nitrate on the Hanford 100D Area in situ redox manipulation (ISRM) barrier longevity. There is a wide spread groundwater plume of 60 mg/L nitrate upgradient of the ISRM barrier with lower nitrate concentrations downgradient, suggestive of nitrate reduction occurring. Batch and 1-D column experiments showed that nitrate is being slowly reduced to nitrite and ammonia. These nitrate reduction reactions are predominantly abiotic, as experiments with and without bactericides present showed no difference in nitrate degradation rates. Nitrogen species transformation rates determined in experiments covered a range of ferrous iron/nitrate ratios such that the data can be used to predict rates in field scale conditions. Field scale reaction rate estimates for 100% reduced sediment (16 C) are: (a) nitrate degradation = 202 ± 50 h (half-life), (b) nitrite production = 850 ± 300 h, and (c) ammonia production = 650 ± 300 h. Calculation of the influence of nitrate reduction on the 100D Area reductive capacity requires consideration of mass balance and reaction rate effects. While dissolved oxygen and chromate reduction rates are rapid and essentially at equilibrium in the aquifer, nitrate transformation reactions are slow (100s of hours). In the limited (20-40 day) residence time in the ISRM barrier, only a portion of the nitrate will be reduced, whereas dissolved oxygen and chromate are reduced to completion. Assuming a groundwater flow rate of 1 ft/day, it is estimated that the ISRM barrier reductive capacity is 160 pore volumes (with no nitrate), and 85 pore volumes if 60 mg/L nitrate is present (i.e., a 47% decrease in the ISRM barrier longevity). Zones with more rapid groundwater flow will be less influenced by nitrate reduction. For example, a zone with a groundwater flow rate of 3 ft/day and 60 mg/L nitrate will have a reductive capacity of 130 pore volumes. Finally, long-term column experiments demonstrated the longevity of the reduced sediment barrier to reduce/immobilize 2 mg/L chromate in the presence of 8.4 mg/L dissolved oxygen (saturation), and 60 mg/L nitrate (maximums observed in the field). Initially the chromate reduction half-life was <0.1 h, 2.4 h by 120 pore volumes, and 17 h by 250 pore volumes. These chromate reduction rates are sufficiently fast relative to the 20-40 day residence time in the field for all chromate to be reduced/immobilized until the sediment is completely oxidized

[en] Transmutation of long-lived fission products is one of the key issues in development and utilization of nuclear power in the world. In the study underway, we are trying to replace the burnable poison in LWR by a mixture of some LLFPs. The main fission products which are included in the high level waste with the half life more than 500 years are ⁷⁹Se, ⁹³Zr, ⁹⁴Nb, ⁹⁹Tc, ¹⁰⁷Pd, ¹²⁶Sn, ¹²⁹I, ¹³⁵Cs. Our main objectives is to employ such an isotope not only with long half life but also with high neutron absorption cross section and appropriate metallic properties within chemical structure. For the matter of calculations, ENDF/B6 as nuclear data library and as series of codes such as WIMS, CITATION, and ORIGEN were used. It has been shown that⁹⁹Tc could be used instead of boron in reactor

[en] The International Conference on Safe Decommissioning for Nuclear Activities took place in Berlin, Germany, from 14 to 18 October 2002. More than 200 senior officials, scientists and local community representatives from 37 countries and three international organizations participated in it. The conference was organized by the IAEA and was hosted by the government of Germany. The conference president was W. Renneberg of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety, Germany. The proceedings of the conference, including a record of the discussions of the panel sessions, will be published by the IAEA. This paper provides a summary of the main findings of the conference. (author)

[en] In the paper, there is a description of the BFS facility, on which an experimental study programme is planned concerning the criticality of MOX fuel-hydrogen moderator systems. The programme implies the creation of a series of critical assemblies with MOX fuel (Pu content ranging from 10-30%) and polyethylene (0-10%). A brief description of the earlier-tested critical assembly BFS-59 is presented. (author)

[en] The Canadian Nuclear Safety Commission (CNSC) has been in the business of regulation for more than 50 years, continually evolving in accordance with the influences around us and our interaction with other regulators around the world. We have, by now, a very good conception of what good regulation should be in the Canadian context. Future regulatory regimes should therefore reflect these concepts. A good regulatory regime is comprehensive, independent, transparent, accountable, balanced between prescription and flexibility, and does not pose an undue burden on those being regulated. Care is taken to reduce overlap and duplication amongst involved agencies while still ensuring that responsibilities are carried out. Effectiveness and efficiency are fundamental objectives of the way in which mandates are achieved. Regulators are, however, pushed in certain directions by stakeholders, particularly the industry and the public. If a licensee responds to regulatory actions in a very formal, legalistic manner, the regulator has no choice but to respond in kind. This can substantially affect not only the amount of effort required on each party's part but also can set the tone of interaction, both of which could influence efficiency and effectiveness. Regulators are themselves subject to other legislation, the associated processes of which are outside their control. An example of such legislation is the Canadian Environmental Assessment Act. This paper will explore the elements of an effective and efficient regulatory regime in the context of nuclear regulation, the implementation of this regime by an 'Ideal Regulator', the major influences on this regime and its implementation, the current situation with respect to the CNSC and a specific example related to uranium mining. (author)

[en] The extraction of U(VI) and Th(IV) from nitric acid media by disulfoxides RSO(CH₂)_nSOR (n=4, 6; R=CH₃(CH₂)₂CH_2^-, CH₃CH(CH₃)CH₂CH_2^-, CH₃(CH₂)₃CH(C₂H₅)CH_2^-) was studied. The extraction laws for U(VI) and Th(IV) by disulfoxides are similar to that by tributylphosphate (TBP), but their extracting and separating ability is superior to that of TBP. The relations between the structure of disulfoxides and their extracting and separating ability are briefly discussed