QUARTERLY REPORT OF THE SOLUTION CORROSION GROUP FOR THE PERIOD ENDING JULY 31, 1958
6 6 5 4 ; 6 6 5 6 4 8 4 : the chemica: stability of possible fuel solutions, and the results obtained from these runs have been compared with data obtained by others. A solution containing 0.04 m UO/sub 2/SO/ sub 4/, 0.03 m CuSO/sub 4/, 0.03 m NiSO/sub 4/, and 0.023 m D/sub 2/SO/sub 4/ in heavy water was not completely stable at 175 deg C or at other higher temperatures. About 7% of the copper was lost at 175 to 275 deg C, and an additional 9% was lost when the temperature was increased to 300 deg C. In the same solution the nickel solubility decreased by 40% up to 200 deg C and then increased up to 275 deg C and at 300 deg C again decreased. Throughout the run no uranium was lost from solution. A second solution containing 0.01 m UO/sub 2/ SO/sub 4/, 0.02 m D/sub 2/SO/sub 4/, 0.01 m CuSO/sub 4/ and 850 ppm nic kel in heavy water was stable at 300 deg C. However, when an additional 450 ppm of nickel was added to the solution, about 10% of the uranium, 6% of the copper, and 20% more nickel than was added in the final addition precipitated from solution. Several other runs were made in which 0.04 m UO/sub 2/SO/sub 4/ solutions containing 0.025 m D/sub 2/SO/sub 2/, 0.03 m CuSO/sub 4/, and 0.04 m alkali or alkalineearth metal suIfates were circulated at 300 deg C in a titanium loop. Solutions containing lithium and rubidium sulfate lost 30 and 15% of their copper, respectively. The loss of copper from solutions containing either beryllium or magnesium suIfate was no greater than 5%. Other runs with the latter two solutions in stainless steel loops showed that the boryllium- containing solution was more corrosive and the magnesium-coutaining solution less corrosive than the same solution without the added sulfate salt. Previous runs in stainless steel loop; have shown that the removal of oxygen from uranyl sulfate solutions results in the precipitation of uranium and severe corrosion of the stainless steel. An attempt was made to minimize corrosion in such cases by the addition of magnesium suIfate to the solution prior to precipitation. No beneficial effect due to the presence of magnesium sulfate was observed. Experiments designed to determine the corrosiveness of the heavy-liquid phase of a uranyl suIfate solution above its separation temperature showed that titanium and Zircaloy-2 were only very slightly atiacked by the heavy phase. Type 347 stainless steel, on the other hand, was attacked at a high rate. Tests that were previously reported showed that the rate of attack of carbon steel by boiler water at 300 deg C was proportional to the oxygen concentration in the range of c l to l0 ppm. Runs made under identical conditions except the solution containing 50 ppm of chloride have shown the chloride ions to be without effect on the corrosion of carbon steel. However, some stree-corrosion cracking of austenitic stainiess steel specimens was observed in the presence of chloride ions. The ability of ruthenium, eithcr as a salt, oxide, or metal, to catalyze the oxidation of chromium (III) to chromium (VI) in sulfuric acid solutions was demonstrated. Since chromium (VI) inhibits corrosion in sulfuric acid solutions, ruthenium can be classed as a corrosion inhibitor although its action is an indirect one. Previously the same effect of ruthenium was demonstrated in uranyl sulfate solutions. Whether ruthenium functions in the sannc manner during in- pile corrosion tests remains to be seen. The removal of oxygen from chloride- containing water at 300 deg C has prevented cracking of type 347 stainless steel during 2000-hr tests. With oxygen presert in similar environments, 100% of the specimens tested underwent cracking in 500 hr or less. The pre-exposure of type 347 stainless steel stress specimens in boiling, chloridefree uranyl sulfate solution was 100% effective in pre
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- DOE Contract Number:
- W-7405-ENG-26
- NSA Number:
- NSA-13-000187
- OSTI ID:
- 4283762
- Report Number(s):
- CF-58-7-132
- Resource Relation:
- Other Information: Orig. Receipt Date: 31-DEC-59
- Country of Publication:
- United States
- Language:
- English
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QUARTERLY REPORT OF THE SOLUTION CORROSION GROUP FOR THE PERIOD ENDING JANUARY 31, 1958
SOLUTION CORROSION GROUP QUARTERLY REPORT FOR THE PERIOD ENDING JANUARY 31, 1956
Related Subjects
BERYLLIUM SULFATES
CATALYSIS
CHLORIDES
CHROMIUM
CHROMIUM ALLOYS
COPPER ALLOYS
COPPER SULFATES
CORROSION
CORROSION PROTECTION
DECOMPOSITION
DEUTERIUM COMPOUNDS
FUEL SOLUTIONS
HEAVY WATER
IN PILE LOOPS
IRON ALLOYS
LITHIUM SULFATES
MAGNESIUM SULFATES
MOLYBDENUM ALLOYS
NI-O-NEL
NICKEL ALLOYS
NICKEL SULFATES
OXIDATION
OXYGEN
PRECIPITATION
RARE EARTHS
REACTION KINETICS
RUBIDIUM SULFATES
RUTHENIUM
STABILITY
STAINLESS STEELS
STEELS
STRESSES
SULFATES
SULFURIC ACID
TEMPERATURE
TITANIUM
TITANIUM ALLOYS
URANYL COMPOUNDS
ZIRCALOY