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[en] The JMTR operation was once stopped in order to be checked & reviewed in August 2006, and the refurbishment and restart of the JMTR was finally determined by the national discussion. The refurbishment was started in FY2007 and was finished in March 2011. However, on March 11, 2011, the Great-Eastern-Japan- Earthquake occurred, and functional tests before the JMTR restart were delayed. On the other hand, based on the safety assessments considering the 2011 earthquake new regulatory requirements were established on December 18, 2013 by the NRA. The new regulatory requirements include the satisfaction of integrities for the updated earthquake forces, tsunami, the consideration of natural phenomena, and the management of consideration in the Beyond Design Basis Accidents (BDBA) to protect fuel damage and to mitigate impact of the accidents. Analyses related to the new regulatory requirements have intensively been performed timely, and an application to the NRA had been submitted in March 27, 2015. After submission of the application, a seismic resistance assessment of the JMTR reactor building was carried out by assuming the standard earthquake ground motion of 810 gal. As a result, it was found that seismic reinforcement work for reactor building and reactor pool wall were required. As a result, it became clear that at least 7 years of reinforcement work and a cost of about 40 billion yen are required for seismic reinforcement and to meet new regulatory standards. At the same time, it was made clear that high availability such as 8 operation cycles per year as originally planned cannot be expected due to aging problem. For this reason, JAEA positioned the JMTR as a decommissioning facility in the mid- and long-term plan of JAEA announced in April 2017. JAEA started to study the construction of a new material testing reactor. The examination results will be compiled by the end of FY2019. (author)
[en] This paper overviewed testing and inspection in the nuclear industry, especially non-destructive test. First, it outlined the testing and inspection of commercial power generation reactors in general, and described the points of attention among the relevant standards. Next, it introduced the following items that the author experienced in face of the troubles that occurred at power generation reactors and test/research reactors in Japan: (1) Sodium leak in the cooling system piping of the fast breeder prototype reactor 'Monju,' (2) Cracks near the welding part between the reactor pressure vessel nozzle safe end and the main pipe of the JPDR II core spray system, (3) Appearance test, measurement of plastic strain, and ultrasonic flaw detection test after the Niigataken Chuetsu-oki earthquake (Kashiwazaki-Kariwa Nuclear Power Station), (4) Water leak appearance test and pressure test of JMTR pressure surge tank, (5) Fuel testing/inspection at JMTR test reactor, and (6) Manufacturing and field application of γ-ray source 169Yb. (A.O.)
[en] Material Test Reactors (MTR) are key large infrastructures to develop, qualify and validate nuclear material under representative normal and accidental conditions to be used in existing or advanced reactor design. The number of powerful Material Test Reactors (MTR) with good accessibility and high neutron flux in the world is very limited. For this reason reactors such as the Belgian Reactor 2 (BR2) are highly demanded for structural and fuel experiments. Each experiment is unique requiring a simulation of the normal or accidental conditions in term of temperature, environment, neutronics or transient conditions. Due to the nature of this activity and the infrastructure cost, safety and operational risks should be addressed with special care. According to the IAEA Safety Requirements No SSR-3 ''Safety of Research Reactors'', it is a best practice to set up a safety committee that is independent of the reactor manager. In this article, the important lessons learned from the SCK•CEN Committee for Evaluation of Experiments established in 1962 will be highlighted. (author)
[en] The Stereo detector is measuring electron antineutrinos from the research reactor at the Institut Laue-Langevin (Grenoble, France). Located at 10m from its core and with a segmented neutrino target, Stereo is searching for light sterile neutrino oscillations as a possible explanation for the Reactor Antineutrino Anomaly observed in 2011. An accurate determination of the detection efficiency of the correlated signal created by the electron antineutrino interaction, + p e + n, called inverse beta decay (IBD) is needed to reach that goal. More concretely, a good understanding of the detection efficiency for the IBD neutrons is required, in both data and simulation, since it is one of the dominant systematic uncertainties of the Stereo analysis. An AmBe neutron source has been deployed throughout the different sub-volumes of the detector, and has been used to study the properties of the neutron detection with high accuracy. Among others, the selection cuts, neutron vertex dependencies and neutron capture models have been specially investigated along this thesis. The AmBe source has been used to test the modelisation of the gamma cascade emitted after a neutron capture on gadolinium (nuclei present in the liquid scintillator). This thesis is focused on studying the most relevant properties in terms of data-to-simulation correction coefficients, providing thus a crucial input in the oscillation analysis of the Stereo experiment.
[en] Radioactive wastes which generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes by the commencing time of disposal. In order to contribute to this work, we collected and analyzed the samples generated from JRR-2, JRR-3 and Hot laboratory. In this report, we summarized the radioactivity concentrations of 25 radionuclides (3H, 14C, 36Cl, 60Co, 63Ni, 90Sr, 94Nb, 93Mo, 99Tc, 108mAg, 126Sn, 129I, 137Cs, 152Eu, 154Eu, 233U, 234U, 238U, 238Pu, 239Pu, 240Pu, 241Pu, 241Am, 243Am, 244Cm) which were obtained from radiochemical analysis of those samples. (author)
[en] The Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL) is a unique, water-cooled, high-flux test reactor capable of performing tests prototypical of PWR operating conditions. The Radiation Measurements Laboratory (RML) was founded in the 1960s to support reactor operations and to conduct independent scientific research. For nearly six decades RML has performed four primary functions: monitoring of radioactivity by gamma-ray spectroscopy of routine reactor samples, fluence rate determinations for irradiation cycles, fission-rate measurements for the ATR-Critical (ATR-C) Facility, and independent research and development of radiation detection systems and applications. Through the decades, RML has seen technological advancements that have been integrated into each of the critical functions of the laboratory. However, many of the measurement and analysis systems employed to this day can be improved by modernization. Recent progress at RML are improving reliability and accuracy of the radiation measurements performed in support of nuclear energy research for the U.S.A. Department of Energy. The control and data collection systems supporting ATR-C have been upgraded. New High-Purity Germanium (HPGe) spectrometers have been procured with liquid nitrogen recycling capabilities to improve up-time and reduce measurement uncertainties. Fluence-rate measurement techniques are also being improved to ensure accuracy, avoid systemic errors, and identify biases. In a parallel effort, new scientific research avenues are being explored which will provide an opportunity to further enhance the utilization of ATR and ensure the sustainability of the RML as nuclear research continues to evolve. The RML is improving the effectiveness of irradiation services provided by ATR while ensuring a sustainable future for nuclear energy research. (author)
[en] Since its commissioning in March 1965, the SAFARI-1 research reactor has achieved many outstanding successes and post 1995, has become one of the most highly utilised nuclear research reactors in the world, with respect to safe and reliable operation and the aim to serve all stakeholders for more than 20 years at ~300 operational days. This gave SAFARI-1 the opportunity to becomes one of South Africa’s and Necsa’s cornerstone facilities, especially during the mid 1990’s with the changing political environment where SAFARI-1’s main application was to be a cost sustainable facility to operate as a commercial production facility of radioisotopes and rendering of irradiation services to various stakeholders. During this period, SAFARI-1 had moved from a way from a low utilised, Monday to Friday research oriented programme, to a highly utilised production facility with little R&D and beam line activities. This is high level of utilisation is evident when looking at the operational hours, in which the first 1 Million Mega Watt hours (1000GWh) was reach in 1995 (30 years from first start-up), followed by reaching the 2 million MWh mark 8.8 years later in 2003. This trend continued and the 3 Million MWh (3000GWh) mark was reached in 2011, and only recently has SAFARI-1 broke through the 4 Million MWh (4000GWh) mile stone. This vast increase in utilisation has accordingly brought various challenges and opportunities with a special qualified and skilled workforce to support the operational programme in all disciplines of engineering, nuclear technology, maintenance, operations, radiation protection, regulatory and licensing, conventional and nuclear safety, quality and environment aspects, waste management as well as security. The last 54 years and especially the 21 years since 1996 where the operational programme required a higher than normal utilization of SAFARI-1, mainly due to the commercial purposes, SAFARI-1 and operational staff had also to withstand apart from the above-mentioned challenges, many other life cycle factors or challenges. These challenges and life cycle factors are related to the ever changing political strategies, regulatory environment, organisational changes, strategic focus or objectives, facility ageing factors, human capacity and skills development, work force factors, operational challenges, technology application, design information and developments and lastly but not limited to the reactor facility operational safety culture related to the management approach followed. The main objective, having it challenges, is for SAFARI-1 to be a sustainable operational irradiation facility until at least 2030 or longer, pending on continuous engineering assessments supported by an ageing management programme, In-Service Inspections, effective maintenance, operational constrains as well as regulatory conditions. (author)
[en] At the previous conferences it has been reported about the effective utilisation of the Rez research reactor LVR-15 in basic, interdisciplinary and applied research. Now, in our contribution we focus our attention on the scientific utilisation of the beam tubes at the low power research reactor. Namely, it is reported about the neutron scattering instrumentation development and the educational possibilities at the low power neutron sources. The feasibility of carrying out the methodology and instrumental development research at the low power neutron sources is demonstrated on designs of several high resolution and high luminosity neutron scattering instruments exploiting Bragg diffraction optics. Some of them have been already realized e.g. for small angle neutron scattering studies or residual strain/stress measurements. As the mentioned instrumental development and testing can be carried out at the low power neutron sources, due to the much lower safety requirements in comparison with the medium and high flux sources, they offer excellent educational and training programmes in neutron scattering or imaging for students.
[en] In 1957 Glenn T. Seaborg conceived and advocated for the construction of the High Flux Isotope Reactor (HFIR) and the Transuranium Processing Plant (since then renamed the Radiochemical Engineering Development Center, or REDC) at Oak Ridge National Laboratory. Heavily shielded hot cells, glove boxes, and laboratories allow recovery of transuranium elements produced in substantial quantities. Seaborg’s vision of HFIR and REDC producing milligram quantities of berkelium, californium, and einsteinium has been fulfilled beginning in 1966 through May 2019 with 78 production campaigns yielding a cumulative totals of 1.2 g of Bk, 10.2 g of Cf, 39 mg of Es, and 15 pg of Fm. Notably, Cf is a neutron source used in many industrial applications including oil exploration; process control systems for the cement industry, coal analysis, and power production; sources to start nuclear reactors and perform nondestructive materials analyses; homeland security and national defense detection devices; and medical research. Isotopes made available through transplutonium production at HFIR/REDC have enabled scientists to study the nuclear properties and reactions, chemical properties, optical properties, and solid-state properties of transplutonium elements. Long-lived isotopes have served as targets in heavy ion accelerators to produce heavier elements leading to the discovery of Rf, Db, Sg, Nh, Fl, Mc, Lv, Ts, and Og. This paper reviews the evolution of the processing flowsheets to produce, separate, and purify transplutonium isotopes, which have evolved over 50 years of operation at HFIR and REDC, and summarizes directions of future work to improve the efficiency of the production operations.
[en] The Institute of Nuclear Physics (INP) in Almaty for more than 18 years produces and supplies all nuclear medicine organizations of the Republic of Kazakhstan with the most used radiopharmaceutical for radionuclide diagnostic 99mTc solution. For production of generators activation 99Mo is used, obtained by irradiation of natural molybdenum oxide at the WWR-K research reactor with a thermal neutron flax 2·1014 n·s-1·cm-2. The “gel” technology, the basis of which have been developed by scientists from Australia and the United States, applied on an industrial scale in India is used to produce 99Mo/99mTc gel generators at the Institute. Specialists of the Institute of Nuclear Physics have improved this technology by developing unique technological equipment for the production of generators in hot cells and creating a new generator design, as well as implementing GMP principles in production. The project of creation of 99Mo/99mTc gel generator production was implemented within the framework of budget programs aimed at the development of new technologies in the Republic of Kazakhstan and the success of the project is largely due to the significant support provided by IAEA through Technical Cooperation and Coordinated Research Projects. (author)