TY - RPRT TI - MCNP® Code Version 6.3.1: Verification & Validation Testing (Rev.1) AU - Josey, Colin James [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000232105806) AU - Clark, Alexander R. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)] AU - Kulesza, Joel A. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000226696339) AU - Lively, Michael Aaron [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000165119852) AU - Pearson, Eric J. [GE Vernova Hitachi Nuclear Energy, Wilmington, NC (United States)] AU - Rising, Michael Evan [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000287122427) PY - 2025 DO - 10.2172/2538303 UR - https://www.osti.gov/biblio/2538303 ID - 2538303 ER -