In order to analyze the processes induced by electrical breakdown and discharge responsible for memory effect in krypton-filled tube at low pressure, experimental data mean value of electrical breakdown time delay as a function of afterglow period tau (memory curve) was used. Analysis showed that in the 1 mu s < tau < 7 ms interval positive ions formed in the previous discharge and in afterglow have a dominant role in secondary emission of electrons from the cathode which lead to initiation of breakdown. In the 7 ms < tau < 30 s interval N(S-4) atoms have a dominant role in secondary electron emission. These atoms are formed during breakdown and discharge by dissociation of nitrogen molecules that are presented as impurities in krypton. For tau > 30 s the concentration of N(S-4) atoms decreases significantly so that the dominant role in initiation of breakdown is taken over by cosmic rays and natural radioactivity. The increase in discharge current leads to the decrease in in the 1 mu s < tau < 7 ms interval due to the increase in positive ion concentration. The increase in applied voltage decreases the values of for tau > 7 ms due to the increase in probability for breakdown. It has also been show that exposure of krypton-filled tube to low dose of gamma ray irradiation as well as UV irradiation with wavelength higher than 300 nm leads to the decrease in . This decrease occurs for tau > 7 ms, when N(S-4) atoms play a dominant role in breakdown initiation.