Effect of oxygen in sodium upon radionuclide release from austenitic stainless steel

Conference · Mon Sep 01 04:00:00 EDT 1975

OSTI ID:4165811

Brehm, W. F.

A major purpose of the Radioactivity Control Technology program is to determine the effect of oxygen in sodium upon release of $sup 54$Mn, $sup 60$Co, and $sup 58$Co from irradiated 316 stainless steel, and the distribution of the deposited nuclides in the test system. Determining the effect of oxygen in sodium upon nuclide release will define purification system equipment and operational requirements for FFTF/CRBR and future LMFBR's. A reduction in nuclide release is necessary to lower gamma dose rates in equipment cells during maintenance and repair operations, which in turn will decrease downtime and maximize plant use factor and reduce doubling time. The work was conducted in Source Term Control Loop No. 1 (STCL-1) with a specimen temperature of 604$sup 0$C (1120$sup 0$F), a loop minimum temperature of 427$sup 0$C (800$sup 0$F), sodium velocity at the specimens of 6.7 to 7.6 m/s (22 to 25 ft/sec) and oxygen levels of 0.5 +- 0.1 ppm and 2.5 +- 0.1 ppm. A reduction of greater than a factor of two in specimen weight loss was observed upon operation of the test system at 0.5 rather than 2.5 ppm oxygen. The corrosion of iron from the specimens was reduced by greater than a factor of five. The release of $sup 54$Mn was reduced by about 30 percent at the lower oxygen level, while the release of $sup 60$Co$sup +$ has an apparent reduction of greater than a factor of three, but with considerable scatter in the data. Reductions of this magnitude are insufficient to completely solve the nuclide release and deposition problem, but sufficient to recommend operation of LMFBR facilities at as low an oxygen level as possible (certainly less than 1 ppm and less than 0.5 ppm if possible). (auth)

• Research Organization: Hanford Engineering Development Lab., Richland, Wash. (USA)
• NSA Number: NSA-33-006736
• OSTI ID: 4165811
• Report Number(s): HEDL-SA--985; CONF-750972--2
• Country of Publication: United States
• Language: English

Related Subjects

*LMFBR TYPE REACTORS-- REACTOR COOLING SYSTEMS
*REACTOR COOLING SYSTEMS-- IMPURITIES
*STAINLESS STEEL-316-- CORROSION
210500* --Nuclear Power Plants--Power Reactors
Breeding
DEPOSITS
EROSION
N50200 -- Metals
Ceramics
& Other Materials--Metals & Alloys
N77500* --Reactors--Power Reactors
Breeding
OXYGEN
SODIUM