In heavily irradiated NaCl explosions can be initiated during irradiation o
r later, after the irradiation, when the samples are heated to temperatures
in the range 100-250 degrees C. As a result of the irradiation Na and Cl-2
precipitates, dislocations and voids are produced, along with stored energ
y (the maximum value observed until now similar to 76 kJ/mol, which is abou
t 18.5% of the enthalpy of formation of NaCl, 411.2 kJ/mol). This implies t
hat heavily irradiated NaCl is a highly energetic material. We have observe
d that the samples, which revealed large radiation-induced voids, explode r
ather easily. In these samples the instability connected with large voids (
hot spots) probably initiates the explosive release of stored energy, which
is in many cases accompanied by characteristic (explosive) sounds. In this
paper we will discuss the nature of the explosions and show that a basical
ly stable insulating compound, such as NaCl, may become unstable after heav
y irradiation.