Records on synthesis of neptunium compounds, recovery and reuse of neptunium by professor N.N.KROT

Professor Krot (Head of the Laboratory of Transuranium Elements Chemistry, Institute of Physical Chemistry, Russian Academy of Sciences) stayed at Tokai Research Establishment, Japan Atomic Energy Research Institute for 45 days from January 16, 1997 to February 28, 1997 by an invitation of the Research group for Moessbauer Spectroscopy of Actinoids, Advanced Science Research Center. In the mean-time, Professor Krot left many memoranda on actinide research for the Research group. This is a compilation of those memoranda in Japanese translation. The contents include many topics, synthesis of neptunium compounds in valence states of 3, 6 and 7'', method for recovery and reuse of neptunium from compounds in a laboratory'', ''records of the neptunium compounds synthesized during his stay'', and so on. Also, important contents of discussions with Professor Krot in the Research Group are summarized. (author)