This third edition of the Gas Quality Program data tabulation for Gasbuggy contains results for the 105 samples received by LRL through March 1971. Results for samples No. 76 through 105 are presented here for the first time. These additional data cover the last 2 mo of the extended-flow production test of the GB-ER nuclear chimney well (September and October 1969), the 2-wk open-flow or blowdown period ending in the second week of November 1969, and the first 15 mo of the ensuing shutin period. At the suggestion of the El Paso Natural Gas Company, we are including in this tabulation total gaseous tritium and krypton-85 concentration results for 31 additional samples. These samples were analyzed by Teledyne Isotopes under contract to El Paso Natural Gas. Also included in this tabulation are the results of an attempt to detect the presence of nongaseous pray emitting radionuclides on particulate matter being carried by the gas stream during the open-flow testing in November 1969, Compared with previous investigations, the negative results obtained suggest a significant reduction in the upper-limit amounts of these nuclides associated with Gasbuggy gas. Some minor corrections have been made in previously published data as a result of our continuing effort to improve the overall quality of the tabulated results. Our present plans are to continue sampling at monthly intervals from the shut-in GB-ER well. When sufficient information becomes available from analyses of these samples, a third revision of this report will be issued.-iii-Contents Foreword to Revision 2 iii Abstract Introduction Sample Log Radionuclide Concentrations LRL Gas Quality Analysis Prograin Radionuclide Concentration Results of Other Laboratories .... Chemical Composition Miscellaneous Determinations Rare Gas Activation Products Tritiated Water Nongaseous Radionuclides nificance. And second, it provides a means for general distribution of the results in advance of the final program reports. By the nature of the Gasbuggy experiment, there can be no definitive conclusion

Analysis of gas from a heated air-filled canister containing a spent fuel assembly before and after rupture of a fuel rod shows that about 1.5 mCi of 14C from the external surface of the assembly was rapidly oxidized and released as 14CO2 in excess oxygen at 275°C and 104rad/hr. After rupture, an additional 0.3 mCi was released, probably also from the external surface. The total 14C inventory in the entire 15×15 rod assembly including structural hardware is estimated to be 690 mCi. These measurements indicate that account will have to be taken of the time distribution of lifetimes of the canisters, and a broad definition of the “engineered system” may be necessary, in order to meet 1OCFR60 requirements with spent fuel in a repository in tuff.

Carbon-14 is produced naturally by cosmic ray neutrons in the upper atmosphere. It is also produced in nuclear reactors, in amounts much smaller than the global inventory. About one-third of this is released directly to the atmosphere, and the other two-thirds remains in the spent fuel. Both the Environmental Protection Agency and the Nuclear Regulatory Commission have established limits on release of the \ in spent fuel. This is of particular concern for the proposed repository in tuff, because of the unsaturated conditions and the consequent possibility of gaseous transport of l *C as COj. existing measurements and calculations of the C inventory in spent.fuel are reviewed. The physical distribution and chemical forms of the C are discussed. Available data on the release of C from spent fuel in aqueous solutions and in gaseous environments of air, nitrogen, and helium are reviewed. Projected '*C behavior in a tuff repository is described. It is concluded that **C release measurements from spent fuel into moist air at temperatures both above and below the in situ boiling point of water as well as detailed transport calculations for the tuff geological environment will be needed to determine whether the 10CFR60 and 40CFR191 requirements can be met.