| Popis: |
Each of the 25 monitor tubes at B and D reactors have been gauged four to six times since they were installed in late 1961 or early 1962. Since October, 1962, the WTG data indicates the average corrosion rate, is 0.25 to 0.30 mils per month. The corrosion rate of the thinnest tube is about the same as the average tube. As expected, the corrosion rate is low and believed to be a measure of top-wall corrosion. It is estimated that it will take approximately one more year (at 6.6 pH) before the bottom wells will have the same average minimum wall thickness as the top walls. During this period, the main problem will be to determine whether the top wells will continue corroding at rates between 0.25 to 0.30 mils per month. it is recommended the 25 tubes at B and D reactors be gauged with the WTG every metal cycle during the coming year. The Process Engineer will continue to analyze the WTG data as it accumulates and recommend further monitoring or replacement, subject to the details authorized in the parent test. |
