2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/142307The results of the experiment searching for 2K-capture with large low-background proportional counter are presented. The comparison of spectra of the background of the proportional counter filled with Kr enriched in $^{78}$Kr (8400 hr) and with natural Kr (3039 hr) is given. A new limit on the half-life of $^{78}$Kr with regard to 2K-capture, T$_{1/2}\geq2.0\cdot10^{21}$ yrs (95% C.L.) has been obtained.4 pages, 7 postscript figures, talk at the XIV-th Int. School "Particles and Cosmology"Nuclear Experimenttext