Nondestructive Examination of Containers with Plutonium-bearing Materials

The first nondestructive examination (NDE) of 3013-type containersas part of the U.S. Department of Energy’s (DOE’s) IntegratedSurveillance Program (ISP)1 was performed in February2005. Since that date 280 NDE surveillances on 255 containershave been conducted. These containers were packaged withplutonium-bearing materials at multiple DOE sites. The NDEsurveillances were conducted at Hanford, Lawrence LivermoreNational Laboratory (LLNL), and Savannah River Site (SRS).These NDEs consisted of visual inspection, mass verification, radiologicalsurveys, prompt gamma analysis, and radiography.The primary purpose of performing NDE surveillances is todetermine if there has been a significant pressure buildup insidethe inner 3013 container. This is done by measuring the lid deflectionof the inner 3013 container using radiographic images.These lid deflection measurements are converted to pressure measurementsto determine if a container has a pressure of 100 psigor greater. Making this determination is required by Surveillanceand Monitoring Plan (S&MP).2 All 3013 containers are designedto withstand at least 699 psig as specified by DOE-STD-3013.3To date, all containers evaluated have pressures under 50 psig. Inaddition, the radiographs are useful in evaluating the contents ofthe 3013 container as well as determining the condition of thewalls of the inner 3013 container and the convenience containers.The radiography has shown no signs of degradation of anycontainer, but has revealed two packaging anomalies.Quantitative pressure measurements based on lid deflections,which give more information than the “less than or greater than100 psig” (pass/fail) data are also available for many containers.Statistical analyses of the pass/fail data combined with analysisof the quantitative data show that it is extremely unlikely thatany container in the population of 3013 containers consideredin this study (e.g., containers packaged according to the DOESTD-3013 by 2006) would exceed a pressure of 100 psig. Atthis time, Los Alamos National Laboratory (LANL) and LLNLcontinue to package containers. Future NDE surveillances willaddress containers packaged after 2006 for both sites as well ascontainers requested by the Materials Identification Surveillance(MIS) working group based on knowledge gained from shelf-lifestudy and surveillance results.