1.1 ,This test method describes the nondestructive assay of scrap or waste for plutonium content using passive thermal-neutron coincidence counting. This test method provides rapid results and can be applied to a variety of carefully sorted materials in containers as large as several thousand liters in volume. The test method applies to measurements of ²³⁸Pu,  ,²⁴⁰Pu, and ²⁴²Pu and has been used to assay items whose total plutonium content ranges from 10 mg to 6 kg (1) .2