The same method could be used in the so-called hydrogen bomb, but also in its variant in which Poland was particularly interested - the neutron bomb. Such a charge mainly destroys living organisms (and therefore soldiers) by irradiation. The problem was to ensure that the "Soviet comrades" would not find out about the trials with such a weapon. In a conversation with Edward Gierek, Professor Kaliski suggested that a test explosion should be carried out in an adit built in the Bieszczady Mountains. The idea was to minimize the possibility of detecting experiments. It was an utopian solution, as both NATO and Russia had adequate equipment to detect underground nuclear explosions. Large sums were allocated for the project, as it was necessary to obtain research equipment, materials and mechanisms that were then embargoed by Western countries. In secret from the intelligence services of NATO, but also the Soviet Union, even the "kryptrons" - special devices that control the launch of explosives in the fuse of an atomic bomb - were obtained by the Polish foreign intelligence. The program to develop the hydrogen or neutron arms amounted to many millions of dollars, contributing to some extent to the collapse of the economy of the People's Republic of Poland in the late 1970s.