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[en] Highlights: • A detailed tritium cycle model of HCPB blanket for CFETR was developed. • Tritium concentrations and retentions inside HCPB blanket, tritium extraction rate and tritium losses of blanket were obtained. • Sensitivity analysis of parameters’ influence on tritium losses of blanket was performed. - Abstract: Based on the HCPB (Helium-Cooled Pebble Bed) blanket of CFETR (Chinese Fusion Engineering Testing Reactor), a more detailed tritium cycle model of HCPB blanket was developed by modeling the breeding parts inside the blanket separately. Utilizing the detailed model, tritium transport analysis of HCPB blanket was carried out. The outputs of the model were the tritium concentrations and tritium retentions at different positions, tritium extraction rate by TES (Tritium Extraction System) and by CPS (Coolant Purification System) and the tritium losses of blanket. In addition, sensitivity analysis of key parameters’ influence on tritium losses and tritium extraction rate by TES was performed. The tritium transport analysis provides valuable reference for the design of HCPB blanket.
[en] Highlights: • Through the calculation method of the model, it was found that the increase of the artificially determined startup inventory I0 causes significant increase of TBRreq and the increase of the achievable tritium breeding ratio TBRachiv leads to the decrease of the Im. • The increase of fueling efficiency and fractional burnup significantly contributes to the decrease of both Im and TBRreq, while the increase of the duty time and availability results in the decrease of TBRreq and the proportional increase of Im. • The outer tritium plant parameters of some subsystems that have relatively big tritium throughput have intense influence on either Im or TBRreq. - Abstract: In order to evaluate the tritium self-sufficiency of fusion plant, citing CFETR (Chinese Fusion Engineering Testing Reactor) as an example, a modified tritium fuel cycle model was developed. The calculation method of this model to obtain the minimum startup inventory I_m and its corresponding required minimum tritium breeding ratio TBR_r_e_q was first introduced. Then the model was utilized to analyze the influence on I_m and TBR_r_e_q by all tritium cycle parameters that were classified into two categories, namely, the tritium burning parameters and the outer tritium plant parameters. As for the tritium burning parameters, the increase of fueling efficiency and fractional burnup significantly contributes to the decrease of both I_m and TBR_r_e_q, while the increase of the duty time and availability results in the decrease of TBR_r_e_q and the proportional increase of I_m. As for the outer tritium plant parameters, it was found that the outer tritium plant parameters of some subsystems that have relatively big tritium throughput have intense influence on either I_m or TBR_r_e_q.
[en] Highlights: • An optimized design of the Small Natural Circulation Lead Cooled Fast Reactor was proposed. • MAs were mixed into the fuel (MOX). • The MA transmutation ratio of the optimized core is 2.73%. • The optimized reactor could run at full power for 10 years without refueling. - Abstract: SNCLFR-100 (Small Natural Circulation Lead Cooled Fast Reactor with 100 MW_t_h), proposed by University of Science and Technology of China (USTC), is a typical modular fast reactor with an array of heterogeneous square fuel assemblies using MOX as the main fuel located in the core, and a preliminary conceptual design has been presented. To extend the full power operating time of the core to 10 years without refueling and improve the transmutation capability of the core, the design optimizations were carried out in this paper, including changing compositions of the fuel, adjusting the relative portion of Pu and U, and changing the type of structure material in the core. In addition, relevant parameters were also optimized. Compared to the original design, the neutron flux distribution became flatter, and the power peak factor of the core dropped from 1.40 to 1.37. The MA transmutation ratio of the optimized core came out to be 2.73%. At the same time, the worth of control rods and the negative reactivity coefficients showed the core has inherent safety.
[en] Highlights: • A modified tritium fuel cycle model with more detailed subsystems was developed. • The mean residence time method applied to tritium fuel cycle calculation was updated. • Tritium fuel cycle analysis for CFETR was carried out. - Abstract: Attaining tritium self-sufficiency is a critical goal for fusion reactor operated on the D–T fuel cycle. The tritium fuel cycle models were developed to describe the characteristic parameters of the various elements of the tritium cycle as a tool for evaluating the tritium breeding requirements. In this paper, a modified tritium fuel cycle model with more detailed subsystems and an updated mean residence time calculation method was developed based on ITER tritium model. The tritium inventory in fueling system and in plasma, supposed to be important for part of the initial startup tritium inventory, was considered in the updated mean residence time method. Based on the model, the tritium fuel cycle analysis of CFETR (Chinese Fusion Engineering Testing Reactor) was carried out. The most important two parameters, the minimum initial startup tritium inventory (I_m) and the minimum tritium breeding ratio (TBR_r_e_q) were calculated. The tritium inventories in steady state and tritium release of subsystems were obtained.
[en] The main constituents of interstellar molecules are 1H, 12C, 14N, 16O, 32S, 28Si. Within them, only 14N nucleus has a quadrupole mement. Therefore the spectra of the interstellar molecules with constituent 14N have the nuclear quadrupole hyperfine splihings. Measurement of the ration of the hyperfine satellite intensities offers impohant astrophysical information. Some research project in this field will be started latter
[en] Clinical application of 80 patients treated with 89Sr for metastatic bony pain was reported the toxic effect and dosage was also evaluated. Of the 17 cases with complete blood sample examination, 7 cases with the dosage of 1.11 - 1.48 MBq/kg showed no changes in leukocyte and platelet count. 10 cases with the dosage of 1.48 - 2.22 MBq/kg showed slight decline 14% and 23% respectively in leukocyte and platelet count, 5 - 6 weeks after 89Sr treatment. As to the pain relief 25 cases 31.25% complete pain free (grade 4), 34 (42.5%) are of significant pain decrease (grade 3), 13 (16.25%) are of slight pain decrease (grade 2), 8 (10.0%) are of no change or even pain aggravated (grade 1), the total efficacy of 89Sr was 90.0% and the significant efficacy (complete pain free + significant pain relief) was 73.75%. The optimal dose of authors' study was within the range of 1.11 - 1.48 MBq/kg. Thereby, it was concluded 89Sr was effective for relief of the metastatic bony pain
[en] The neutronics calculations for the DFLL-TBM in ITER have been performed with the Monte Carlo code MCNP/4C and nuclear cross-section data from the FENDL 1.0 data library based on the integrated three-dimensional ITER design model, in which the vertical test blanket port was modified to allow the inclusion of test blanket modules by the Chinese home-developed CAD/MCNP interface code, i.e. MCAM. The neutron flux, tritium production and nuclear heating distribution in the DFLL-TBM are presented. (authors)
[en] A neutronics analysis of the Dual-cooled Lithium-Lead (DLL) Breeder Blanket for the fusion power reactor named FDS-II is presented to achieve the goal of sufficient TBR (Tritium Breeding Ratio) on the basis of which nuclear heating distribution will be given. The home-developed multi-functional (transport/burnup/optimization) neutronics code Visual BUS1.0 and its multi-group data library HENDL1.0/MG are applied in the neutronics calculations. MCNP4C and FENDL-2/MC are used for neutronics benchmark calculation. (author)
[en] Chinese Fusion Engineering Testing Reactor (CFETR) is a test tokamak reactor to bridge the gap between ITER and future fusion power plants and to demonstrate generation of fusion power in China. In fusion power plants, tritium is generated from the reaction of neutron and Lithium. One of the missions of CFETR is the full cycle of tritium self-sufficiency. For the mission, a Helium Cooled Solid Breeder blanket (HCSB) was proposed for CFETR and its conceptual design has been carried out. In order to assess the capacity of the tritium breeding and irradiation damage of first wall of the HCSB blanket during the 8 years’ engineering test stage, this paper presents the time trend of TBR analysis and irradiation damage assessment of HCSB blanket based on the three-dimensional (3D) neutronics model which is created by McCad. In the 3D neutronics model, the outboard blanket on equatorial plane is described based on the detailed 3D engineering model. The calculations were performed by MCNP and FISPACT with FENDL/2.1 data library. The impact analysis of the thickness of coolant plates (CP) and the structural material content in CPs to the TBR is assessment.
[en] The calculation and analysis on the activation levels of the different regions of dual-cooled lithium-lead (DLL) breeder blanket of FDS-II, including afterheat, dose rate, activity and biological hazard potential after shutdown, were carried out with the neutronics code system VisualBUS and multi-group working library HENDL1.0/MG. The safety and environment assessment of fusion power (SEAFP) strategy for the management of activated material is here applied to the DLL blanket, to define the suitable recycling (reuse of activated material) procedure and the possibility of clearance (declassification of the material with low activity level to non-active waste). (authors)