Interim report II: Production test IP-634, half-plant low pH test water treatment at D Reactor process tube examination results

摘要

Two half-plant tests were conducted at D reactor to evaluate the effect of process water pH on corrosion of aluminum process tubes and fuel elements. The first test demonstrated that a reduction in coolant pH from 7.0 to 6.6 reduced aluminum corrosion by a factor of between 2 and 3. Fuel weight loss data from the second test indicated that reducing coolant pH from 6.6 to 6.2 would result in an additional factor of 2 to 3 reduction in aluminum corrosion. This report presents the results of ex-reactor process tube measurements an thermocouple probe annular temperature measurements made on six new process tubes irradiated during the second test. These results were combined with similar data obtained from six new process tubes irradiated during the first test. The combined results were used to estimate the effect 7.0, 6.6, and 6.2 pH on corrosion of aluminum process tubes.