A5102730763- Nuclear reactor physics and engineering
- Nuclear Materials and Properties
- Graphite, nuclear technology, radiation studies
- Nuclear and radioactivity studies
- Nuclear Physics and Applications
- Muon and positron interactions and applications
- Particle accelerators and beam dynamics
- Nuclear Engineering Thermal-Hydraulics
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Crystallography and Radiation Phenomena
- Magnetic properties of thin films
- Fusion materials and technologies
- Cold Atom Physics and Bose-Einstein Condensates
- Spectroscopy and Laser Applications
- Magnetic Properties of Alloys
- Ammonia Synthesis and Nitrogen Reduction
- Automotive and Human Injury Biomechanics
- Boron Compounds in Chemistry
- Electron and X-Ray Spectroscopy Techniques
- Medical Imaging Techniques and Applications
- Advancements in Photolithography Techniques
- Atomic and Molecular Physics
- Graphene research and applications
- Advanced Frequency and Time Standards
Japan Atomic Energy Agency
2014-2024
Advanced Science Research Center
2004
Tohoku University
2001
A 10 keV positron beam has been developed using coaxially symmetric electromagnetic lenses for reflection high-energy diffraction (RHEPD) experiments. The brightness is ∼107 e+/s/cm2/rad2/V which comparable to that obtained enhancement technique. parallel and normal coherence lengths are over 100 40 Å, respectively, long enough observe patterns associated with large surface super-structures. RHEPD from a Si(111)-(7×7) reconstructed have successfully observed much better quality than...
Japan Atomic Energy Agency has conducted a conceptual design of 50 MWt small-sized high temperature gas cooled reactor (HTGR) for multiple heat applications, named HTR50S, with the outlet coolant 750°C and 900°C. It is first-of-a-kind commercial plant or demonstration HTGR system to be deployed in developing countries 2020s. The concept HTR50S satisfy user requirements multipurpose applications such as district heating process supply based on steam turbine power generation by helium hydrogen...
An innovative plutonium burner concept based on high temperature gas cooled reactor (HTGR) technology, "Clean Burn", is proposed by Japan Atomic Energy Agency (JAEA). That expected to be as an effective and safe method consume surplus accumulated in Japan. A similar General Atomics (GA), Deep Burn, cannot introduced because of its adopting highly enriched plutonium, which shall infringe a Japanese nuclear nonproliferation policy according Japan–US reprocessing negotiation. The Clean Burn can...
The investigation on the characteristics of void reactivity coefficients for high-conversion-type core FLWR (HC-FLWR) concept MA recycling has been performed. Void are major restrictions design HC-FLWR recycling, because loaded makes worse. Therefore, it is important to investigate as a mechanism reactor physics. Thus, in this study, performed using exact perturbation calculations. In theory, related variation cross section, and divided into scattering, leakage, absorption, fission terms....
The particular characteristics of an effective delayed neutron fraction are found in a heterogeneous fuel solution system the present study. Those against conventional systematic understanding successfully employed homogeneous system. Therefore, systems should be validated by new understanding. For understanding, is described geometrical buckling based on Fermi age theory relation between and concentration To establish numerically evaluated with its distribution As result, it that becomes...
Abstract Japan Atomic Energy Agency (JAEA) has been developing a methodology for nuclide generation-depletion and decay heat evaluations High Temperature Gas-cooled Reactors (HTGRs). We are planning to perform validation of the evaluation method with isotopic composition data obtained from HTGR type fuel irradiation tests (AGR tests) performed at Idaho National Laboratory. As first step this plan, preliminary core calculation model Advanced Test Reactor (ATR) is continuous-energy Monte Carlo...
A study on reduction of potential radiotoxicity for spent fuel by using high-temperature gas-cooled reactors (HTGRs) has been performed. Unlike partitioning and transmutation (P&T), the reactor concept is investigated from viewpoint generation itself. To reduce radiotoxicity, 238U, which generates Pu, Am Cm, should be excluded. Therefore, we proposed HTGR fueled new-concept fuels with alternative matrixes instead 238U. Those are yttria-stabilized zirconia (YSZ) thorium, fissile material...
We have started the development of a spin-polarized positron beam. In order to obtain highly spin polarized beam, 68Ge-68Ga source will be produced using nuclear reaction 69Ga(p,2n)68Ge. The optimum proton bombardment energy for 69Ga target is simulated 25 MeV Induced Radioactivity Analysis Code (IRAC). A newly designed holder also used as capsule.
JAEA (Japan Atomic Energy Agency) has conducted feasibility studies of the fuel and reactor core for plutonium-burner HTGR (High Temperature Gas-cooled Reactor). The increase internal pressure, which is caused by generations CO gas stable noble gases, considered to be one major causes TRISO (TRI-structural ISO-tropic) failure at high burn-up. generated chemical reaction graphite making up buffer layer with free-oxygen released from kernel fission. are fission products, also kernel. Although...
The investigation on the characteristics of void reactivity coefficients for high-conversion-type core FLWR (HC-FLWR) concept MA recycling has been performed. Void are major restrictions design HC-FLWR recycling, because loaded makes worse. Therefore, it is important to investigate as a mechanism reactor physics. Thus, in this study, performed using exact perturbation calculations. In theory, related variation cross section, and divided into scattering, leakage, absorption, fission terms....
In order to ensure the sustainable energy supply in future based on matured light water reactor (LWR) technologies, a concept of innovative for flexible fuel cycle (FLWR) has been investigated JAEA. The utilizes tight-lattice core loaded with plutonium mixed oxide (MOX) fuel, and consists two steps chronological sequence. first step realizes high conversion type one (HC-FLWR), which is basically intended keep smooth technical continuity from current LWR / MOX-LWR technologies. second...