THE NORTHERN MARSHALL ISLANDS RADIOLOGICAL SURVEY: A QUALITY CONTROL PROGRAM FOR RADIOCHEMICAL ANALYSES ABSTRACT More than 16,000 radiochemical analyses were performed on about 5,400 samples of soils, vegetation, animals, fish, invertebrates, and water to establish amounts o f 137, $5 241 Am, and plutonium isotopes in the Northern Marshall Islands. 90“Sr, Three laboratories were contracted by Lawrence Livermore National Laboratory to perform the radiochemical analyses: Environmental Analysis Laboratory (EAL), Richmond, California; Eberline Instrument Corporation (EIC), Albuquerque, New Mexico; and Laboratory of Radiation Ecology (LRE), University of Washington, Seattle, Washington. The analytical precision and accuracy were monitored by regularly including duplicate samples and natural matrix standards in each group of about 100 samples analyzed. Based on the duplicates and standards, over 83% of the radiochemical analyses in this survey were acceptable--97% of the analyses by EAL, 45% of the analyses by EIC, and 98% of the analyses by LRE. INTRODUCTION The Northern Marshall Islands Radiological Survey (NMIRS) wasa large-scale effort to collect soil, vegetation, animal, fish, invertebrate, and water samples and assess the radiation dose from the ingestion and inhalation pathway and external environments of 12 atolls and 2 islands in the Northern Marshall Islands. The Lawrence Livermore National Laboratory (LLNL) was responsible for this effort, including the collection and processing of the various samples.! Overall, about 5,400 samples were collected and over 16,000 radiochemical analyses were performed to establish the amounts of specific radionuclides in the soils, vegetation, animals, fish, invertebrates, and water. For such an extensive analytical program, no one laboratory had the capability to analyze all the samples in a reasonable time. Accordingly, three laboratories were contracted to perform the required analyses. Any analytical program depends on the quality of the measurements being made. Most laboratories spend a certain part of their effort to establish the accuracy and reproducability of their analytical work. Blind interlaboratory comparisons such as the Department of Energy (DOE) intercalibration exercise” and analysis of natural matrix |