Positronium In Thawed Water

Parameters of the positron annihilation spectra for pure water previously subjected to the freeze -thaw process are measured. It is shown that orthopositronium lifetime in melted water slightly vary with time after melting (typical time is less than few hours) and then reach the value corresponding to ordinary water. This may indicate that molten water is a nonequilibrium system with a rather long relaxation time. This phenomenon may reflect the process of restructurizing of large clusters of water molecules linked through hydrogen bonds.