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This paper presents a compendium of allowable masses for a variety of gamma and neutron emitting isotopes (with varying impurity levels of beryllium in some of the actinide isotopes) that, when loaded in an unshielded radioactive material transportation packaging, do not result in an external dose rate on the surface of the package that exceeds 190 mrem/hr (190 mrem/hr was chosen to provide 5% conservatism relative to the regulatory limit). These mass limits define the term “Small Gram Quantity” (SGQ) contents in the context of radioactive material transportation packages. The term SGQ is isotope-specific and pertains to contents in radioactive material transportation packages that do not require shielding and still satisfy the external dose rate requirements. Since these calculated mass limits are for contents without shielding, they are conservative for packaging materials that provide some limited shielding or if the contents are placed into a shielded package. Two sets of mass limit results are presented: (1) mass limits calculated with a “voided sphere” model, and (2) mass limits calculated with the unshielded radioactive material transportation packaging Model 9977-96.

The neutronics and safety characteristics of a PWR core loaded with fuel made from SRS recovered uranium have been analyzed. These results are compared to those of a standard commercial fuel loaded core. For both cases, equilibrium cycle three-dimensional core models have been developed to accurately quantify the fuei cycle penalty factor associated with high U-236 content in SRS derived fuel. A 0.28 wt% overenrichment is required to compensate for each 1.0 •:,t% of U-236 in SRS derived fuel in order to match the cycle length. Doppler and moderator coefficients have become slightly more negative with the increase in U-236 content along with a slight reduction of control rod worth, boron worth and shutdown margin. These changes will not impact the safety or operation of a commercial nuclear plant. Thus, the feasibility of using SRS recovered uranium in the form of commercial nuclear fuel has been established from the neutronic and safety point of view. The real issue is the radiological problem related to SRS derived fuel and its effect on worker safety.

Background and Introduction Since the 1960's, the Department of Transportation Specification (DOT Spec) 6M packages have been used extensively for transportation of Type B quantities of radioactive materials between Department of Energy (DOE) facilities, laboratories, and productions sites. However, due to the advancement of packaging technology, the aging of the 6M packages, and variability in the quality of the packages, the DOT implemented a phased elimination of the 6M specification packages (and other DOT Spec packages) in favor of packages certified to meet federal performance requirements. [1] DOT issued the final rule in the Federal Register on October 1, 2004 requiring that use of the DOT Specification 6M be discontinued as of October 1, 2008. A main driver for the change was due to the fact that the 6M specification packagings were not supported by a Safety Analysis Report for Packaging (SARP) that was compliant with Title 10 of the Code of Federal Regulations part 71 (10 CFR 71). [2,3]