Cladding hulls activity

High-Level Solid Waste Treatment. Cladding hulls and dissolver solids are generated as wastes from reprocessing LWR fuels. The alpha activity associated with these head-end wastes is normally low, but as a precautionary measure the WTF provides an area where these wastes may be given an extended tertiary HNO3/KF/ HC1 leach. Experimental studies with mixed-oxide reactor fuels (10,11,12) suggest that actinide losses can be held to 0.01 or less if fluoride and chloride are present in the leachant. 

HLW arising in solid form, mainly cladding hulls, has activity concentrations more than two orders of magnitude lower than liquid HLW. It presents somewhat different technical problems, which wiU be discussed briefly in this chapter. 

Cladding hulls. Cladding hulls as collected from the chop-leach head end are radioactive due to activation products in the zircaloy and to fission products and actinides from (U,Pu)02 adsorbed at the inside of the hulls. The principal activation products are Co, Sb/ Te, and Ni. Their total activity is on the order of 10 /rCi/g zircaloy after 6 years and about 100 times lower after 100 yrars. The fission-product activity after 6 years is of the same order of magnitude and is dominated by Cs, Sr, and tritium. The residual (U,Pu)02 after leaching is estimated to be of the order of 0.1 percent of the charge. 

Intermediate Level and Long-lived waste present a mean activity of over one million Bq.g and are characterized by a significant presence of long lived radionuclides. For AREVA La Hague concerns, it is mostly composed of metal structures (cladding, hulls and end caps). It also comes from residues (waste from effluent treatment, equipment, etc.) originating from the operation and maintenance of nuclear facilities. 

Hulls Handling. After the fuel has been dissolved, the residual pieces of zirconium cladding, referred to as hulls, are rinsed and removed from the dissolver vessel. The decay of activation products provides sufficient heat to ensure drying of the hulls and preclude hydrogen formation caused by the radiolysis of water. 

In addition, the copper industry s market development activities have resulted in appHcations such as clad ship hulls, sheathing for offshore platforms, automotive electrical systems including electric vehicles, improved automobde radiators, solar energy, fire sprinkler systems, parts for fusion reactors, semiconductor lead frames, shape memory alloys, and superconducting ceramics (qv) containing copper oxides. 

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