[en] Content of the Japanese program of water cooled reactor modernization is revealed. The beginning of the program realization was in 1985. Some governmental programs for the modernization program support are considered. Besides the program, during seven last years in Japan is discussed the program aimed at prolongation of the operating NPP lifetime. Specialists singled out approximately ten components in BWR and twelve - in PWR which are the most weak spots from the point of view of admissible prolongation of the Japanese NPP operation