Traceability of Nondestructive Assay to -the National Measurement System

The concept and definition of traceability to the national measurement system is discussed. Traceability is considered a flexible, general term which only has meaning when the method used to trace the measurement results is clearly defined. Methods are proposed which provide the ability to show the consistency of any NBA measurement system with national plutonium and uranium standards. The difficulties in using working or industry NDA standards to provide traceability are discussed. Comparative measurements are proposed as the essential step in attaining a consistent national NDA measurement system and as the replacement for primary NDA standards.