Investigation of the directions of special drawers loaded in ZPPR-9, -10A, -10B, and -10C of JUPITER experiments

Yokoyama, Kenji   ; Ishikawa, Makoto*

In the International Handbook of Evaluated Reactor Physics Benchmark Experiments (IRPhEP) edited by OECD/NEA, nine ZPPR experimental cores named ZPPR-9, 10A, 10B, 10C, 13A, 17A, 18A, 18C, and 19A, which are mock-up critical experiments for sodium-cooled MOX-fueled fast reactors in the JUPITER cooperative program, are included as reactor physics benchmarks. In order to build the as-built modeling of a ZPPR experimental core, the "all master model (AMM)" map and the drawer masters are used which are attached in the ZPPR benchmark as EXCEL files. Although these materials are usually enough to reproduce a complete ZPPR as-build modeling, there is one exception for several ZPPR cores with respect to special narrow drawers called "poison safety rods (PSR)" or "shim rods." These narrow drawers have a void region in the half part of the drawer to insert absorber materials in case of emergent shutdown or criticality adjustment. To get the exact direction of the narrow drawers, the direction of the void region (Right or Left, hereafter, R or L) must be designated in the AMM maps and the drawer masters. Unfortunately, those data of JUPITER-I series (ZPPR-9, 10A, 10B and 10C) did not distinguish the direction of the narrow drawers. JAEA has surveyed the narrow drawer directions of these four ZPPR cores from the original experimental core maps and the loading records which were made by ANL experimenters. New appendices for the four ZPPR core benchmarks are prepared as EXCEL files to summarize the narrow drawer directions obtained by JAEA survey, to make it possible to build the as-built modeling of the ZPPR experimental cores.