A research and development program aimed at devising processes for the economical recovery of the potentially valuable long-lived fission products from Purex waste has been under wat at Hanford for several years. When this work has begun, the concentrated waste was primarily a nitric acid solution (6 to 10 M HNO3) containing the fission products and relatively small concentrations of iron, sulfate, and other corrosion products. Flowsheets based on classical separation schemes and rather similar to processes used by the Isotopes Division at the AEC's Oak Ridge operation served to separate the desired fission products from one another and from the corrosion products (1,2,3).These separation schemes employed careful step-wise pH adjustment to precipitate first the iron and then to separate the desired fission products from one another. The flowsheets were demonstrated on a pilot-plant scale with full-level plant waste. However, since the earlier work was complete, plant operations have been modified....

The measurements reported here are companion measurements to those reported earlier in HW-63585. The only significant difference between the measurements is that 1.8 w/o enrichment UO2 fuel was used for the first set, and 2.6 w/o enrichment UO2 fuel was used for the measurements described in this report. The new results will be presented graphically, and for completeness, the details of the measurement will be included here as well as in HW-63585.

Four capsules containing Al-1.65 w/o Pu and Al-12 w/o Si-1.65 w/o Pu were charged into the MTR. These capsules will be irradiated to a burnup of 80-100% of the plutonium atoms to determine the stability of the material at high exposures. An additional sixteen capsules containing 5 to 20 w/o Pu in Al and Al-Si have been prepared. Eight are awaiting reactor space and should be charged soon. The remaining eight are being recanned to increase the end gap between the core and the can. Also four capsules containing high density UO2-PuO2 pellets canned in Zircaloy are awaiting assignment of reactor space.

A 19-rod Zircaloy-clad half-length PRTR spike element successfully irradiated to high plutonium burnout at full power in the ETR shoved partial bonding of the core and cladding. Unsatisfactory autoclave films on the Zircaloy cladding of the PRTR Al-Pu fuel elements are delaying final assembly of the first 30 clusters. Further conditioning of the autoclaves and the availability of permanent etching facilities are expected to correct the present difficulties.

Ultrasonic equipment has been developed for nondestructive testing of Hanford fuel elements. The ultrasonic method has replaced the Frost Test for bonding layer inspection in the Hanford canning line, and provides more accurate and reliable results at lower cost. The method has also been adopted to the testing of new fuel elements for which no other method is available.

A knowledge of the mechanical and physical properties of uranium is important in understanding and explaining its pile behavior. The effects of irradiation on the properties of uranium will be dealt with in another chapter. However, it is important to know and understand the pre-irradiation properties of uranium prior to investigating the effects of irradiation.