Ruminations on NDA Measurment Uncertainty Compared to DA Uncertainty

Conference · Sun Jul 11 00:00:00 EDT 2010

OSTI ID:982362

Salaymeh, Saleem ^[1]; Croft, Stephen ^[2]; Goldberg, Steve ^[3]; Preston, Lynne ^[4]; Santi, Peter ^[2]; Sprinkle, James ^[2]; Venkataraman, Ram ^[5]; Pfennigwerth, Glenn ^[6]; Dewberry, Raymond ^[1]; Clare, Aaron ^[1]

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1. Savannah River National Laboratory (SRNL), Aiken, SC (United States)
2. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
3. New Brunswick Laboratory (NBL), Argonne, IL (United States)
4. US Department of Energy (USDOE), Washington, DC (United States)
5. Canberra Industries Inc., Meriden, CT (United States)
6. Oak Ridge Y-12 Plant (Y-12), Oak Ridge, TN (United States)

It is difficult to overestimate the importance that physical measurements performed with nondestructive assay instruments play throughout the nuclear fuel cycle. They underpin decision making in many areas and support: criticality safety, radiation protection, process control, safeguards, facility compliance, and waste measurements. No physical measurement is complete or indeed meaningful, without a defensible and appropriate accompanying statement of uncertainties and how they combine to define the confidence in the results. The uncertainty budget should also be broken down in sufficient detail suitable for subsequent uses to which the nondestructive assay (NDA) results will be applied. Creating an uncertainty budget and estimating the total measurement uncertainty can often be an involved process, especially for non-routine situations. This is because data interpretation often involves complex algorithms and logic combined in a highly intertwined way. The methods often call on a multitude of input data subject to human oversight. These characteristics can be confusing and pose a barrier to developing and understanding between experts and data consumers. ASTM subcommittee C26-10 recognized this problem in the context of how to summarize and express precision and bias performance across the range of standards and guides it maintains. In order to create a unified approach consistent with modern practice and embracing the continuous improvement philosophy a consensus arose to prepare a procedure covering the estimation and reporting of uncertainties in nondestructive assay of nuclear materials. This paper outlines the needs analysis, objectives and on-going development efforts. In addition to emphasizing some of the unique challenges and opportunities facing the NDA community we hope this article will encourage dialog and sharing of best practice and furthermore motivate developers to revisit the treatment of measurement uncertainty.

• Research Organization: Savannah River Site (SRS), Aiken, SC (United States); Savannah River National Laboratory (SRNL), Aiken, SC (United States); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); New Brunswick Laboratory (NBL), Argonne, IL (United States); Oak Ridge Y-12 Plant (Y-12), Oak Ridge, TN (United States); Canberra Industries Inc., Meriden, CT (United States); US Department of Energy (USDOE), Washington, DC (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
• DOE Contract Number: AC09-08SR22470
• OSTI ID: 982362
• Report Number(s): SRNL-L2200-2010-00081; TRN: US1004374
• Resource Relation: Conference: 51. INMM Annual Meeting (INMM 51), Baltimore, MD (United States), 11-15 Jul 2010
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ACCURACY
ALGORITHMS
COMPLIANCE
CRITICALITY
DECISION MAKING
NUCLEAR FUELS
PERFORMANCE
PROCESS CONTROL
RADIATION PROTECTION
SAFEGUARDS
SAFETY
WASTES
Nuclear Criticality Safety Program (NCSP)
Physical Measurements
Nondestructive Assay Instruments
Needs Analysis
Objectives
On-Going Development Efforts