SULFEX-THOREX AND DAREX-THOREX PROCESSES FOR THE DISSOLUTION OF CONSOLIDATED EDISON POWER REACTOR FUEL: LABORATORY DEVELOPMENT

Technical Report · Tue Nov 01 04:00:00 EST 1960

OSTI ID:4116916

Ferris, L M; Kibbey, A H

Modified flowsheets, based on laboratory-scale studies, are presented for batch dissolution of Consolidated Edison power reactor fuel. The stainless- steel jacket may be dissolved in either boiling 5M HNO/sub 3/--2M HCl (Darex process) or boiling 6M H/sub 2/SO/sub 4/ (Sulfex process). In each case a waste solution containing about 50 g of stainless steel per liter is formed. With ThO/ sub 2/--UO/sub 2/ core pellets, whose density is about 90% of theoretical, the uranium lost during decladding is expected to be less than 0.1% with either method. The high-density fuel pellets will be dissolved in 200% excess of boiling 13M HNO/sub 3/--0.04M NaF containing 0.04 or 0.1M Al(NO/sub 3/)/sub 3/ after decladding by the Darex or Sulfex processes, respectively. Core dissolution will require at least 25 hr and will yield a solution containing about 1M thorium and about 9M HNO/sub 3/. The dissolution time could be shortened slightly by decreasing the aluminum concentration in the dissolvent or by adding about 0.5M Fe(NO/sub 3/)/sub 3/. Sulfate ion, which might be present after Sulfex decladding, decreased the core dissolution rate. The rate of dissolution of the fuel pellets was inversely proportional to the density of the pellets; the initial 10-min rate of dissolution in boiling 13M HNO/sub 3/--0.04M NaF--0.1M Al(NO/sub 3/)/sub 3/ of 95% ThO/sub 2/-- 5% UO/sub 2/ pellets decreased from about 16 to 2 mg min/sup -1/ cm/sup -2/ as the pellet density increased from 60 to 94% of theoretical. The solubility of stainless steel in sulfuric acid at 25 deg C de creased from 60 to 40 g/liter as the acidity increased 4 to lON. (auth)

• Research Organization: Oak Ridge National Lab., Tenn.
• DOE Contract Number: W-7405-ENG-26
• NSA Number: NSA-15-002700
• OSTI ID: 4116916
• Report Number(s): ORNL-2934
• Country of Publication: United States
• Language: English

Related Subjects

ALUMINUM NITRATES
BOILING
CHEMISTRY
DAREX PROCESS
DENSITY
DIAGRAMS
FUEL CANS
FUELS
HYDROFLUORIC ACID
IONS
IRON NITRATES
JACKETS
LABORATORY EQUIPMENT
NITRIC ACID
PELLETS
REACTORS
SEPARATION PROCESSES
SODIUM FLUORIDES
SOLUTIONS
STAINLESS STEELS
SULFATES
SULFEX PROCESS
SULFURIC ACID
THOREX PROCESS
THORIUM OXIDES
URANIUM
URANIUM DIOXIDE
WASTE SOLUTIONS