Radiological survey of the Mallinckrodt Chemical Works, St. Louis, Missouri

Abstract

The results of a radiological survey of part of the Mallinckrodt Chemical Works (former Destrehan and Broadway Street plants), St. Louis, Missouri, are presented. During the period 1942 through 1957, this site was used for various projects involving the production of purified uranium from pitchblende concentrates. The survey included measurements of the following: residual alpha and beta-gamma contamination levels in the existing buildings that were used in the uranium projects; external gamma radiation levels at 1 m above the surface in these buildings and outdoors around these buildings; radon and radon daughter concentrations in the air in these buildings; uranium, radium, actinium, and thorium concentrations in surface and subsurface soil on the site; concentrations of radionuclides in water and sediment found in drains both inside and outside the buildings; and concentrations of radionuclides in ground and surface water on the site and in river water taken near the site. Alpha and beta-gamma contamination levels inside and outside some of the buildings were above limits set by current federal guidelines concerning the release of property for unrestricted use. Elevated external gamma radiation levels were measured at some outdoor locations and in some of the buildings. Licensable concentrations of uranium were found in soil at some places, and the concentration of uranium in a water sample taken from a core hole between Buildings 100 and 101 was in excess of limits set by current federal standards. Radon and radon daughter concentrations in three buildings were in excess of current federal guidelines for nonoccupational radiation exposure.