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
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