[en] We present an updated measurement of sin 2phi₁ in B⁰ → cc-barW decays and first evidence for CP-violating asymmetries in B → π⁺π^- decays. We also report the first observation of the ν_c(2S) meson. The results are based on analyses of a sample of 41.8 million BB-bar meson pairs from the decays of the υ(4S) resonance, collected with the Belle detector at the KEKB asymmetric-energy e⁺e^- collider. For the B → π⁺π^- CP-violating asymmetry measurement, we fully reconstruct one neutral B meson as a B → π⁺π^- CP eigenstate and identify the flavor of the accompanying B meson from its decay products. From the dependence of the asymmetry on the time intervals between the two B meson decay points, we obtain the CP-violating asymmetry parameters S_ππ -1.21 _-0.27^+0.38(stat)_-0.13^+0.16(syst) and A_gpπ +0.94 _-0.31^+0.25(stat) ± 0.09(syst). In the η_c(2S) meson search, we examined the K_sK^-π⁺ invariant mass distribution in a sample of exclusive B → KK_SK^-π⁺ decays. We find a narrow peak mass M = 3654 ± 6(stat) ± 8(syst)MeV/c² and width Γ < 55 MeV/c². The properties agree with heavy-quark potential model expectations for the η_c(2S) meson, the n = 2 singlet S-wave charmonium state

[en] In this project, research and developments have been done to verify the applicability of advanced design features of Gen IV SFR system. Through the evaluation of various design concept, fluid system of Gen IV SFR was established which is enhanced in safety and economics. Especially, passive decay heat removal system PDRC was developed with high reliability through enough capacity and diversity. For the development of advanced technologies, basic design of experimental facility were established in order to conserve overall and local thermal hydraulic phenomena of PDRC and major experiment requirements were established. In order to develop super-critical CO₂ Brayton Cycle system, design concept of new airfoil type heat exchange was developed and through an experimental test, performance of the airfoil type compact heat exchanger was evaluated. To develop performance analysis code, an NSSS analysis model and related control systems were developed, a model for a supercritical CO₂ Brayton Cycle was implemented. A Rankine cycle model including control systems was developed

[en] In this work, we report improved measurements of the product branching fractions $\mathcal{B}(B^{+}\to {\overline{D}}^0{D}_{s0}^{*+}(2317))\times \mathcal{B}(D_{s0}^{*+}(2317)\to D_s^{+}{\pi }^0)=(8.0_{-1.2}^{+1.3}\pm 1.1\pm 0.4)\times 10^{-4}$ and $\mathcal{B}(B^0\to D^{-}{D}_{s0}^{*+}(2317))\times \mathcal{B}(D_{s0}^{*+}(2317)\to D_s^{+}{\pi }^0)=(10.2_{-1.2}^{+1.3}\pm 1.0\pm 0.4)\times 10^{-4}$, where the first errors are statistical, the second are systematic and the third are from $D$ and $D_s^{+}$ branching fractions. In addition, we report negative results from a search for hypothesized neutral (${\mathbf{z}}^0$) and doubly charged (${\mathbf{z}}^{++}$) isospin partners of the $D_{s0}^{*+}(2317)$ and provide upper limits on the product branching fractions $\mathcal{B}(B^0\to D^0{\mathbf{z}}^0)\times \mathcal{B}({\mathbf{z}}^0\to D_s^{+}{\pi }^{-})$ and $\mathcal{B}(B^{+}\to D^{-}{\mathbf{z}}^{++})\times \mathcal{B}({\mathbf{z}}^{++}\to D_s^{+}{\pi }^{+})$ that are more than an order of magnitude smaller than theoretical expectations for the hypotheses that the $D_{s0}^{*+}(2317)$ is a member of an isospin triplet. The analysis uses a $711{\mathrm{fb}}^{-1}$ data sample containing 772 million $B\overline{B}$-meson pairs collected at the $\mathrm{{\rm Y}}(4S)$ resonance in the Belle detector at the KEKB collider.

[en] The characteristics of mechanical pump and electromagnetic (EM) pump for liquid sodium coolant in a liquid metal reactor are compared and analysed as a design concept of KALIMER coolant pumps. The type of coolant circulation pump affects the selection of reactor type, economics, and reliability of reactor. Though the mechanical pump has much application experience and give satisfaction to the reliability of developed reactor type, the possibility of development is limited and its large weight and volume have a negative effect on the design of the economical liquid metal reactor. The large scale electromagnetic pump has not been verified yet, but it is expected to be demonstrated in time. Because the size of EM pump is small relative to the mechanical pump, the compact reactor design is possible. Therefore the selection of EM pump can be one of the methods to improve the economics. Since the shape of EM pump can be varied according to the arrangement of electromagnet coils, a new or unique reactor type can be developed easily in the process of KALIMER development. In the view point of economic LMR development, it is desirable to adopt the electromagnetic pump. (author). 50 refs., 11 tabs., 24 figs

[en] Liquid sodium is widely used as a coolant of LMR(Liquid Metal Reactor) because of its physical and nuclear properties. However, the liquid sodium is very chemically reactive with oxygen and water so that the study on the sodium fire plays an important role in the LMR safety analysis. In this study, a sodium fire model is suggested to analyze the sodium pool fire where both the flame and the reaction products are considered. And also, sodium pool fire analysis computer code, SOPA, is developed. The sensitivity study on the experimental parameters such as the thermal radiation from flame to atmospheric gas, the vessel cooling and the duration of sodium spill was performed. The results showed good agreements with experimental data in the literature. (author)

[en] ΔE-E telescope high energy radiation detector was designed, fabricated, and tested at the 35 MeV proton energy. We developed the computer code to calculate the energy loss of projectile ions in the matter. Using the code, we designed and fabricated a detector to measure 15 ∼ 50 MeV protons. The detector was successfully tested to measure the energy of protons and deuterons and to identify the ions. We also successfully developed a small radiation detector which is composed CsI(Tl) scintillator and PIN Si photodiode. The characteristics of BGO, NaI(Tl), and CsI(Tl) scintillation detectors were measured and analysed. In future, we would like to extend the present result to the development of a higher energy proton detector and a heavy ion detector. (author)

[en] The basic concept of fluid and I and C systems of KALIMER-600 was developed and the computer codes required to materialize system concept were also implemented through the R and D program. Based on the analysis results of the design characteristics for the similar reactor types developed in the foreign countries, the system design technologies with adoption of the innovative ideas were developed. With the development, expansion and reinforcement of the methodologies required according to the progress of development and design of the system and the experimental verification of the developed computer code, the excellent and innovative outcomes were produced

[en] We present molecular dynamics simulation results for molecular structure, density profile and radial distribution functions of water, cation and methane in hydrated potassium montmorillonite clays. The systems we have studied consist of eight Otay Montmorillonite unit cells forming a clay patch of 21.12 x 18.28 A² with a thickness of 6.56 A, eight potassium interlayer cations, with 0.5, 1.0 and 2.25 CH₄ per unit cell, corresponding to 11.5, 11.0 and 9.75 H₂O per unit cell. The calculations are conducted in constant (N, V, T) ensembles at T = 300 K and with a layer spacing of 18 A. Visualization of simulation results in the 1.0 CH₄ per unit cell system indicated that the methane molecule is nested inside the hexagonal cavities of the clay surface oxygen due to the fact that the clay surfaces include neutral regions that are hydrophobic. The calculated CH₄-O coordination number of around 20 for 0.5 and 1.0 CH₄ per unit cell systems is consistent with previous simulations. Our simulations show that water in potassium montmorillonite formed stretched hydrogen bonds with either the clay surface or other water molecules

[en] In order to analyze the sodium discharge phenomena after a rupture disk breakage in the event of a sodium-water reaction, thermal-hydraulic analysis model was developed. The simple calculation model for the sodium discharge and the cover gas temperature and pressure was set up to investigate the termination time of sodium clearing. Through this work, the preliminary analysis for the sodium draining phenomena of a SWR event in KALIMER was carried out. It is confirmed that the sodium clearing time was about 16 minutes after tube leakage, and final temperature of cover gas space was about 967 .deg. C when the inflow rate of hydrogen gas is 1.6kg/sec and the diameter of rupture disk is 0.5m

[en] Evaluation of turbulence models is performed for a better prediction of thermal stratification in an upper plenum of a liquid metal reactor by applying them to the experiment conducted at JNC. The turbulence models tested in the present study are the two-layer model, the k-w model, the v2-f model and the low-Reynolds number differential stress-flux model. When the algebraic flux model or differential flux model are used for treating the turbulent heat flux, there exist little differences between turbulence models in predicting the temporal variation of temperature. However, the v2-f model and the low-Reynolds number differential stress-flux model better predict the steep gradient of temperature at the interface of thermal stratification, and only the v2-f model predicts properly the oscillation of temperature. The LES is needed for a better prediction of the amplitude and frequency of the temperature fluctuation