Abstract: This invention relates to a method of predicting the long-term dose rates from radioactive material on the interior, wetted surfaces of the primary coolant piping of nuclear power reactors. The electrochemical potential of the cooling water of a nuclear power plant is measured over a short-term period with an electrochemical potential measuring device that has an unprefilmed measuring electrode. The results of these electrochemical potential measurements are divided by the result at a prescribed short period of exposure, and these normalized electrochemical potential fractions are plotted versus the logarithm of time. The negative of the slope of the straight line through the plotted data is divided into the measured average Co-60 concentration in the cooling water, and a standard curve of long-term dose rate versus this parameter is used to predict the eventual long-term radiation build-up performance of the nuclear power plant in which the electrochemical potential measurements are made.

Abstract: An improved method for decontaminating the coolant system of water-cooled nuclear power reactors and for regenerating the decontamination solution. A small amount of one or more weak-acid organic complexing agents is added to the reactor coolant, and the pH is adjusted to form a decontamination solution which is circulated throughout the coolant system to dissolve metal oxides from the interior surfaces and complex the resulting metal ions and radionuclide ions. The coolant containing the complexed metal ions and radionuclide ions is passed through a strong-base anion exchange resin bed which has been presaturated with a solution containing the complexing agents in the same ratio and having the same pH as the decontamination solution.