Introduction: Static, total immersion corrosion tests were carried out at room temperatures with Carboloy grades 44-A, 78, 907, X-3119-A and X-3119-B in Redox process solutions (ANL, June 1, 1949 Flowsheet) 1AX, 1AF, and 1AS.

Large savings in waste storage space may be realized by lowering the pH at which TBP waste is stored. Additional savings in neutralizing chemicals and operating time would also increase the monetary gain from such a process change. However, before such a change could be made, the corrosive effect of TBP waste at a lower pH on the mild steel waste storage tanks had to be determined.

This paper discusses technical bases, operating standards, and instrumentation systems required to achieve the goal of nuclear safety in operation of high-level reactors. Because of the relatively long neutron lifetime in a thermal reactor and the comparatively modest time rates of reactivity change associated with fission poison and temperature effects, the rod system used for compensating reactivity transients and for maintaining flux distribution control may be operated manually. Manual operation of the reactor and the prediction of pile reactivity statue during outages of course involve factors of human error, normal reaction time, and judgment. It is the aim to specify procedures for the operation such that manual control of the reactor may be adequately maintained at all times within the range of reasonably expected calculational errors and human reaction times. The technical considerations used in developing these standards, including the available monitoring indications are discussed first; then the automatic trip devices which should back up the procedures are also mentioned.

At the request of F. W. Albaugh of the Engineering Department, the corrosive effect of 1% uranium nitrate hexahydrate solution on aluminum at 100 C has been measured. The corrosion of aluminum in uranium nitrate solution has been shown in laboratory tests to be too severe to permit the use of aluminum for containing hot uranium nitrate solutions. A minimum corrosion penetration rate of 2 mils per day was observed with M-329 aluminum in 1% uranium nitrate hexahydrate in pH 2 aqueous solution at 100 C.