[en] The JMTR Hot Laboratory facility has been operated since 1971, and used to examine various kinds of post-irradiation examinations (PIEs) on fuels and materials mainly irradiated in the JMTR. PIEs on fuel specimens are carried out in concrete cells with microscope lead cells attached, consisting of eight concrete cells and four lead cells. The current main PIEs carried out in the cells are as follows: PIEs on LWR fuels base-irradiated in the JMTR to be subjected to the NSRR (Nuclear Safety Research Reactor, located at JAERI-Tokai) experiments to study fuel behavior under reactivity-initiated accident conditions. PIEs on LWR fuels with gadolinium as burnable poison to extend burn-up of fuels and to flatten power distribution in LWR core. In addition, re-capsuling of and re-instrumentation to fuel rods irradiated in a BWR for power ramping tests using the BOCA (BOiling water CApsule) facility to study BWR fuel behavior under power changing conditions at normal operation are being carried out actively in the concrete cells. This paper describes the current main activities made in the concrete cells with the microscope lead cells attached. (author)