SIMMER-III: A Computer Program for LMFR Core Disruptive Accident Analysis; Version 3.A Model Summary and Program Description

Yamano, Hidemasa; Fujita, Satoshi; Tobita, Yoshiharu; Kamiyama, Kenji; Kondo, Satoru; Morita, Koji*; Fischer, E. A.; Brear, D. J.; Shirakawa, Noriyuki*; Cao, X.; et al.

JNC TN9400 2003-071, 340 Pages, 2003/08

JNC-TN9400-2003-071.pdf:1.54MB

An advanced safety analysis computer code, SIMMER-III, has been developed to investigate postulated core disruptive accidents in liquid-metal fast reactors (LMFRs). SIMMER-III is a two-dimensional, three-velocity-field, multiphase, multicomponent, Eulerian, fluid-dynamics code coupled with a space-dependent neutron kinetics model. By completing and integrating all the physical models originally intended at the beginning of this code development project, SIMMER-III is now applicable to integral reactor calculations and other complex multiphase flow problems. A systematic code assessment program, conducted in collaboration with European research organizations, has shown that the advanced features of the code have resolved many of the limitations and problem areas in the previous SIMMER-II code. In this report, the models, numerical algorithms and code features of SIMMER-III Version 3.A are described along with detailed program description. Areas which require future model refinement are also discussed. SIMMER-III Version 3.A, a coupled fluid-dynamics and neutronics code system, is expected to significantly improve the flexibility and reliability of LMFR safety analyses.

SIMMER-IV: A Three-Dimensional Computer Program for LMFR Core Disruptive Accident Analysis - Version 1.B Model Summary and Program Description -

kondo, Satoru; Yamano, Hidemasa; Tobita, Yoshiharu; Fujita, Satoshi; Morita, Koji*; Mizuno, Masahiro*; *

JNC TN9400 2001-003, 307 Pages, 2000/11

JNC-TN9400-2001-003.pdf:8.33MB

An advanced safety analysis computer code, SIMMER-III, has been developed at Japan Nuclear Cycle Development Institute (JNC) to more realistically investigate postulated core disruptive accidents in liquid-metal fast reactors. The two-dimensional framework of SIMMER-III fluid dynamics has been extended to three dimensions to a new code, SIMMER-IV, which is currently (in Version 1) coupled with the existing two-dimensional neutronics model. With the completion of the first SIMMER-IV version, the applicability of the code is further enhanced and the many of the known limitations in SIMMER-III are eliminated. The sample calculations demonstrated the general validity of SIMMER-IV. This report describes SIMMER-IV version 1.B, by documenting the models, numerical algorithms and code features, along with the program description and input and output information to aid the users. Further extension of the code is planned to couple the three-dimensional neutronics in the future.

Preparation of methods to calculate pin-wise intra-subassembly power density distribution of a new in-pile experimental reactor for FBR safety research

Mizuno, Masahiro*; Uto, Nariaki

JNC TN9400 98-007, 147 Pages, 1998/11

JNC-TN9400-98-007.pdf:8.32MB

A design study of a new in-pile experimental reactor, SERAPH (Safety Engineering Reactor for Accident PHenomenology), for FBR safety research has progressed at JNC (Japan Nuclear Cycle Development Institute). SERAPH is intended for various in-pile experiments to be performed under steady state and various transient operation modes. Heavy water is selected as a coolant material for heat removal of the SERAPH driver core during the experiments. Control rods are needed to conduct the experiments, and a control rod with heavy water follower is considered as one of the promising ideas and is now under investigation. In this idea, care must be taken to avoid production of local power peaks which are caused by neutron moderation in the follower and may appear in the vicinity of the boundary between the control rod and its neighboring fuel subassembly, since deuterium has an excellently high moderation power. Therefore, preparation of some methods of evaluating power density distribution in detail is required for control rod design. This report describes preparation of a set of neutronic calculation methods to evaluate intra-subassembly power density distribution including local power peaks around a control rod. A two-dimensional S transport calculation code TWOTRAN-II is selected as a tool for evaluating neutron transport phenomena near the control rod with no cares for statistical influence. A two-dimensional rectangular super-cell model, which is a physical model composed of a control rod and its surrounding fifteen fuel sub-assemblies, and a method to construct the super-cell model based on thirteen unit cells are created, considering neutron mean free path near a control rod. Two processing tools are newly developed to generate a material region map and mesh boundaries for an efficient super-cell construction procedure and to obtain pin-wise power densities based on calculated mesh-wise neutron flux data. The results in this report are expected to be ...

Experimental evaluation of torsional fatigne strength of welded bellows and application to design of fusion device

; Yamamoto, Masahiro; ; *; *; *; *

Journal of Nuclear Science and Technology, 21(5), p.341 - 355, 1984/00

https://doi.org/10.3327/jnst.21.341

no abstracts in English

Study on disrupted core neutronics; Analysis of FCA VIII-2 fuel slumping experiments based on recent core analysis methods

Fujita, Satoshi; Fukushima, Masahiro; Kugo, Teruhiko; Ishikawa, Makoto; Tobita, Yoshiharu; Mizuno, Masahiro*

no journal, , 

no abstracts in English