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# Content and Pedagogy presenter: Akshay Kumar akshay@cdac.in

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• leçon - matière potentielle : initial reading depth
• cours magistral
• exposé - matière potentielle : issues
• revision
Content and Pedagogy presenter: Akshay Kumar 1
• lot of syllabus
• node of the map
• lots of problem
• hierarchy content
• creation of prerequisite content
• content creation content
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Subjects

##### Hierarchy

Informations

Data Extraction
Superimposed Importance Mesh Geometry
Weight Window Lower Weight Bound
(MCNP4C Input data)
PRESMIRE (Data Extraction)
POSTSMIRE (fluxWeight Window)
Continuousenergy Cross Section Data (JENDL3.3)
MCNP4C (Forward Calculation) END
Data Extraction
Material Card
Source Biasing
Fig. 1flow of the lower weight boundary of the Calculation weight window and forward calculation
and analyze the shielding calculations for a transport cask in detail with the variance reduction technique based on the Consistent Adjoint Driven Importance Sampling (CADIS) 59) 10) methodology andthe empirical formula.CADIS me thodology makes use of the adjoint function that is associated with particle importance which is the contribution of a particle with respect to the objective. The Monte Carlo method with variance reduction shown in the present study should be helpful to those in performing calculations for similar some shielding structures. II. SMIRE System
1. Description of the SMIRE System Figure 1shows the schematic flow of the SMIRE System to generate the lower weight boundary of the weight win dow. 11) MCNP4C codeis provided with “superimposed impor tance mesh” which can create the space partition based on mesh that is independent of the geometrical cell. In the present study, the meshbased weight window parameter generation system has been developed. In this system, com plicated cell partitions for the variance reduction are not necessarily required. The lower weight boundary of the weight window in each mesh is determined as follows: a)Each coordinate of the superimposed importance meshes is calculated from the mesh information in the MCNP input data. b)Each of these adjoint fluxes in the superimposed impor tance meshes is calculated by onedimensional 12) deterministic code, MCNPANISN_W.This code makes it possible to solve the onedimensional neutron transport problem specified by MCNP input data.Fig ure 2shows the flow of the MCNPANISN_W:
START
Extraction of the source information from MCNP input ・The location of the source region ・Source strength distibution
Particle production from source region NPS=NPS+1, NPS：Number of particle histories
ITAL=ITAL+1 ITAL：The number of mesh
Extraction of the geometry information from MCNP input ・The coordinate of the intersection between the  straight-line and each cell boundary ・Material composition ・Atom density
Preparation of the input data for ANISN-W ・Preparation of the mixing table for each mesh ・Determination of mesh coordinate
One-dimentional transport calculation by ANISN-W
Determination of source
Generation of random number for decision of the generation-position of particle Preparation of the input data for ANISN-W
Neutron transport Calculation
N ITAL=ITAL ? max Y N NPS=NPS ? max Y Calculation of the adjoint flux END Fig. 2 Flowchartof the MCNPANISN_W calculation
(1)A detector locating point is arranged at the center of each mesh which constitutes the geometric form described in MCNP input. (2)The location of the particle production is stochas tically decided from the source region and the source strength distribution described in MCNP input. (3)Particle energy is stochastically decided from the distribution of source energy spectrum described in MCNP input. (4)The distance in a straight line between the loca tion of the particle production and the detector location is decided from the geometry data de scribed in MCNP input. (5)The coordinate of the intersection between the straight line and each cell boundary is decided from the geometry data described in MCNP input. The material composition and the atom density each cell is also obtained from the MCNP input. (6)The onedimensional model for the deterministic Sn transport code is made from the calculation conditions acquired from the process (2) to (5). The transport calculation is performed by 13) ANISNW code. (7)Calculation conditions for ANISNW are as fol lows: Basic geometry form: sphere Source: Shell source problem
1.0E05
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1.0E08 0
1.0E05
1.0E06
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50 100150 200 Distance from center of the cask (cm) History=3000 History=5000 History=10000 (Adjoint flux at 14.9 MeV)
250
1.0E10 0 50100 150 200 250 Distance from Center of the cask (cm) History=3000 History=5000 History=10000 (adjoint flux at energy 1.11MeV)Fig. 4MeV andof adjoint flux at energy 14.9 Comparison 1.11 MeV