No abstract

The Radiological and Environmental Sciences Laboratory administers three separate programs that include the use of prepared evaluation material to assess the performance of the participant laboratories. The performance materials include a simple liquid matrix to soil containing organic compounds to synthetic excreta containing known concentrations of radionuclides. The paper discusses the quality control associated with the preparation of these materials. The concept of synthetic-standard enhancement of a natural matrix is briefly discussed to demonstrate homogeneity. The use of verified standards and the assurance of homogeneity by preparation method and characterization are shown to be the necessary components of useful and accurate performance evaluation materials. Because each of the performance programs is tailored to the specific needs of the participants, a discussion of the acceptance criteria is also included.