CHEMICAL PROCESSING TECHNOLOGY. Quarterly Progress Report, July-September 1963

Technical Report · Mon Feb 24 00:00:00 EST 1964

DOI:https://doi.org/10.2172/4035638· OSTI ID:4035638

Bower, J.R. ed.

essing operations resulted in overall recovery of 99.8% of the U from Al-U type fuels (12 varieties) available for processing. Dissolution and first cycle extraction were conducted nt an average rate of 24 kg of U per day for MTR- ETR fuel and at lower rates for other fuels; overall plant and individual cycle decortamination was equivalent to that of earlier Al processing runs. Newly modified processing equipment, including large volume neutronpoisoned rework and recovery equipment, and a TBP solvent decortamination unit, performed satisfactorily. Dissolution of refractory Al--U fuel was not accelerated by an attempted contact activntion, but the data suggest that the lower burnup alloy from the interior of a fuel slug is preferentially dissolved, leaving a hard-to- dissolve shell containing the higher burnup alloy. Zirconium fuel processing studies led to significant results in a number of areas. It was found that the use of dissolved B as a neutron poison does not affect dissolution processes or the stability of the resulting Al-complexed solutions, and that U-Zircaloy-2 fuel was dissolved continuously by an aluminum nitrate-hydrofluoric acid dissolvent, but a corrosion resistant container material may not presently be available for this reagent. UO/sub 2/-- ZrO/sub 2/ wafers from advanced PWR fuel were dissolved nt good rates in concentrated hydrofluoric acid, eg, 5 mg/(cm/sup 2/ )(min) at 20 M acid, and the addition of oxalic acid to hydrofluoric acid dissolver reagent gave about a 50% increase in U solubility. Corrosion tests of Monel and Carpenter-20 in Zr dissolver product solution showed that Monel had uniform corrosion rates of up to 5 mils/morth; Carpenter-20 had lower average corrosion rates but showed greater susceptibility to localized attack. Dibutyl phosphate was found to be generated in unexpectedly large amourts in the first cycle extraction column, and only in small amounts in the first cycle product evaporator, in the first detailed study of TBP and its degradation products under ICPP opernting conditions. Distribution of various phosphate species in first cycle streams is reported and analyzed critically. A laboratory-scale hydrated ZrO/sub 2/ adsorber for DBP was successfully regenerated with 1M NaOH; 97% of the adsorbed DHP was eluted with 12 column volumes of wash solution. Electrolytic dissolution tests in the Model 1 pilot dissolver gave unlform dissolution (in any horizortal plane) of bundles of 3/4-in., type 304 stainless steel tubing at a current utilization factor of 1.9 g/(amp)(hr). Tests to date indicated desirable design changes, and a Model 2 dissolver is being readied for installntion. Several batch dissolutions of irradiated OMRE fuel indicated that irradiation has little effect upon the dissolution process but that decontamination of dissolver components may be difficult. Other subjects studied include dissolver size from the standpoint of nuclear safety, reliability of charging fuel in the correct orientation, and mechanical requirements of dissolver insulating materials. Studies on decontamination of aluminum nitrate by the freeze-melt technique indicate that 500 g of aluminum nitrate should be recovered for each gram retnined in the scrub solution with the fission products. While conditions existing in the pilot unit favor nucleation rather than crystal growth, a tendency toward agglomeration of small crystals gives settling rates adequate to make the unit operable. Measurement of the solubility of strontium nitrate in the nitric acid-aluminum nitrate scrub solution from the apparatus indicates that strontium should not precipitate in the scrub solution-fission product concentrate. Waste calcining facility modifications were completed this period in preparation for operation with high-level ICPP aluminum nitrate waste solution. A summary of the safety analysis of this facility is presented. Nuclear poisoned fuel storage racks, designed to permit closer spacing of fuel elements in the storage canal, are discussed and pictured in some detail.

• Research Organization: Phillips Petroleum Co. Atomic Energy Div., Idaho Falls, Idaho
• Sponsoring Organization: USDOE
• DOE Contract Number: AT(10-1)-205
• NSA Number: NSA-18-017930
• OSTI ID: 4035638
• Report Number(s): IDO-14625
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-64
• Country of Publication: United States
• Language: English

Related Subjects

CHEMISTRY
ABSORPTION
ACIDITY
ADSORPTION
ALLOYS
ALUMINUM ALLOYS
ALUMINUM COMPLEXES
ALUMINUM COMPOUNDS
ALUMINUM NITRATES
BORON
BORON COMPOUNDS
BURNUP
BUTYL PHOSPHATES
CARPENTER
CHEMICAL REACTIONS
COMBUSTION
CONFIGURATION
CONTROL
COPPER ALLOYS
CORROSION
CORROSION PROTECTION
CRITICALITY
CRYSTALLIZATION
CURRENTS
DECOMPOSITION
DECONTAMINATION
DIAGRAMS
DISTRIBUTION
ELECTROCHEMISTRY
ELECTROLYSIS
EXTRACTION COLUMNS
FABRICATION
FILTERS
FISSION PRODUCTS
FUEL ELEMENTS
FUELS
HEAT RESISTING METALS
HIGH TEMPERATURE
HYDROFLUORIC ACID
LABORATORY EQUIPMENT
MEASURED VALUES
MECHANICAL STRUCTURES
MELTING
MIXING
MONEL
NEUTRONS
NI