[en] Technical progress on four variants of the high-temperature gas-cooled reactor (HTGR) is presented with emphasis on the nuclear heat source for the steam cycle cogeneration application. This report describes (1) the advancement of the 2240-MW(t) HTGR-SC/C nuclear heat system and component design; (2) resolution of priority tehnical issues; (3) recommendations on enhanced safety features for the HTGR-SC/C reference design; (4) preparation of long-range program plans; and (5) results of studies on the design development of the HTGR process heat direct and indirect cycle nuclear heat source. Details of an alternate core support concept for the HTGR process heat application are given, and a conceptual design investigation for a new 250-MW(t) HTGR modular reactor system for process heat application is described. Studies on the application of the HTGR-SC/C for synfuel production are included, along with technology, cost, safety, and plant operability evaluations of the direct and indirect cycle HTGR sensible energy transportation and storage systems. The HTGR high-temperature process heat application is also presented