Project Rio Blanco. Environmental surveillance summary report, Part 2, July 1973-December 1976

Project RIO BLANCO was a joint venture undertaken by the US Atomic Energy Commission (AEC) representing the federal government, and CER Geonuclear Corporation representing private industry. As originally conceived, Phase I of the project involved the simultaneous detonation of three nuclear devices in a single emplacement well, and was the third event in the AEC's Plowshare program to develop peaceful uses for nuclear devices. The main purpose of the RIO BLANCO experiment, as well as that of the other two Plowshare detonations, was to investigate the feasibility of using nuclear detonations in deep underground formations where the gas was too tightly held to be released under other known techniques. A total of approximately 9000 radiochemical analyses have been done on 4110 environmental samples pertaining to Project RIO BLANCO by the Department during the period July, 1973 through December, 1976. These include: 3186 air particulate filter samples; 54 air moisture samples; 34 sediment and soil samples; 9 compressed air samples; 44 municipal water supply samples; 122 special well samples; 622 river and stream samples; and 39 snow samples. Levels of radioactivity in the environment and salinity in the surface and well waters were determined before the detonation so that any undesirable changes caused by the detonations could be more easily identified. The collected data identify environmental levels of radioactivity for an extensive area of western Colorado. This report is prepared in two parts. Part I covers the period January 1, 1971 through June 30, 1973, including pre-shot activities and results of surveillance for the six weeks following the detonations. Part II contains the results of environmental surveillance during the periods of re-entry and production test flaring of the gas from the cavities produced by the nuclear explosions and during the period at final shutdown and abandonment of the site. 18 figs., 1 tab