being activated by the neutron flux and subsequently being released and transported to other parts of the primary system. Laboratory measurements(16) of the solubility of several nickel ferrite stoichiometries as a function of pH, temperature and dissolved hydrogen indicate that solubilities tend to increase at higher temperatures when the solution pH is higher. Most recently, initial results from the high pH tests at Ringhals-4 in Sweden(17) have shown that the radiation fields are significantly lower than the typical plants at the comparable operation time. Ringhals-4 has operated at a pH of 7.3 (maximum LiOH concentration of 3.3 ppm) for much of its ~2 years of operations. It must be cautioned that operating at higher LiOH concentrations (Li≥3.5 ppm) in the coolant may result in higher fuel surface oxidation.
(1) L.D.Anstine, et. al., “BWR Corrosion-Product Transport Survey”, EPRI NP-3687 (September 1984).
(2) A.Strasser, et. al., “Corrosion-Product Buildup on LWR Fuel Rods”, EPRI NP-3789 (April 1985).
(3) L.D.Anstine, “BWR Radiation Assessment and Control Program: Assessment and Control of BWR Radiation Fields”, Volume 2, EPRI NP-3114 (May 1983).
(4) S.Uchida, et. al., J. Nucl. Sci. Tech., 24, 385–392 (May 1987).
(5) American Nuclear Society, “American National Standard Radioactive Source Term for Normal Operation of Light Water Reactor” ANSI/ANS-18.1–1984.
(6) C.C.Lin, et. al, “Corrosion Product Transport and Radiation Field Buildup Modeling in the BWR Primary System”, 2nd Int. Conf. Water Chemistry of Nuclear Reactor System, BNES, October 1980, Paper 46; Nuc. Tech. 54, 253 (1981).
(7) C.C.Lin and F.R.Smith, “BWR Cobalt Deposition Studies, Final Report”, EPRI NP-5808 (May 1988).
(8) C.A.Bergmann and J.Roesmer, “Coolant Chemistry Effects on Radioactivity at Two Pressurized Water Reactor Plants”, EPRI NP-3463 (March 1984).
(9) C.A.Bergmann, et. al., “The Role of Coolant Chemistry in PWR Radiation-Field Buildup”, EPRI NP-4247 (October 1985).