The method of neutron diffraction and isotopic substitution was used to determine the hydrogen-bond structure as defined by g(OH)(r) in a 1 m aqueous electrolyte solution of sodium chloride at two thermodynamic states, one subcritical with T=300 degrees C and P=120 bar, and the other supercritical T=460 degrees C and P=800 bar (the critical temperature oi 1 m sodium chloride is 425 degrees C). The results are similar to those found in pure water substance, and confirm the progressive disruption of the hydrogen bond network brought about by an increase in temperature. (C) 1997 American Institute of Physics. [S0021-9606(97)50844-0].