ASTM C1807-15
(Guide)Standard Guide for Nondestructive Assay of Special Nuclear Material (SNM) Holdup Using Passive Neutron Measurement Methods
Standard Guide for Nondestructive Assay of Special Nuclear Material (SNM) Holdup Using Passive Neutron Measurement Methods
SIGNIFICANCE AND USE
5.1 This guide assists in satisfying requirements in such areas as safeguards, SNM inventory control, nuclear criticality safety, waste disposal, and decontamination and decommissioning (D&D). This guide can apply to the measurement of holdup in process equipment or discrete items whose neutron production properties may be measured or estimated. These methods may meet target accuracy for items with complex distributions of SNM in the presence of moderators, absorbers, and neutron poisons; however, the results are subject to larger measurement uncertainties than measurements of less complex items.
5.2 Quantitative Measurements—These measurements result in quantification of the mass of SNM in the holdup. They include all the corrections and descriptive information, such as isotopic composition, that are available.
5.2.1 High-quality results require detailed knowledge of radiation sources and detectors, radiation transport, calibration, facility operations, and error analysis. Consultation with qualified NDA personnel is recommended (Guide C1490).
5.2.2 Holdup estimates for a single piece of process equipment or piping often include some compilation of multiple measurements. The holdup estimate must appropriately combine the results of each individual measurement. In addition, uncertainty estimates for each individual measurement must be made and appropriately combined.
5.3 Scan—Radiation scanning, typically gamma, may be used to provide a qualitative description of the extent, location, and the relative quantity of holdup. It can be used to plan or supplement the quantitative neutron measurements. Other indicators (for example, visual) may also indicate a need for a holdup measurement.
5.4 Nuclide Mapping—To appropriately interpret the neutron data, the specific neutron yield is needed. Isotopic measurements to determine the relative isotopic composition of the holdup at specific locations may be required, depending on the facility.
5.5 Spot Check an...
SCOPE
1.1 This guide describes passive neutron measurement methods used to nondestructively estimate the amount of neutron-emitting special nuclear material compounds remaining as holdup in nuclear facilities. Holdup occurs in all facilities in which nuclear material is processed. Material may exist, for example, in process equipment, in exhaust ventilation systems, and in building walls and floors.
1.1.1 The most frequent uses of passive neutron holdup techniques are for the measurement of uranium or plutonium deposits in processing facilities.
1.2 This guide includes information useful for management, planning, selection of equipment, consideration of interferences, measurement program definition, and the utilization of resources.
1.3 Counting modes include both singles (totals) or gross counting and neutron coincidence techniques.
1.3.1 Neutron holdup measurements of uranium are typically performed on neutrons emitted during (α, n) reactions and spontaneous fission using singles (totals) or gross counting. While the method does not preclude measurement using coincidence or multiplicity counting for uranium, measurement efficiency is generally not sufficient to permit assays in reasonable counting times.
1.3.2 For measurement of plutonium in gloveboxes, installed measurement equipment may provide sufficient efficiency for performing counting using neutron coincidence techniques in reasonable counting times.
1.4 The measurement of nuclear material holdup in process equipment requires a scientific knowledge of radiation sources and detectors, radiation transport, modeling methods, calibration, facility operations, and uncertainty analysis. It is subject to the constraints of the facility, management, budget, and schedule, plus health and safety requirements, as well as the laws of physics. This guide does not purport to instruct the NDA practitioner on these principles.
1.5 The measurement process includes...
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C1807 − 15
Standard Guide for
Nondestructive Assay of Special Nuclear Material (SNM)
1
Holdup Using Passive Neutron Measurement Methods
This standard is issued under the fixed designation C1807; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.5 The measurement process includes defining measure-
ment uncertainties and is sensitive to the chemical
1.1 This guide describes passive neutron measurement
composition,isotopiccomposition,distributionofthematerial,
methods used to nondestructively estimate the amount of
various backgrounds, and interferences. The work includes
neutron-emitting special nuclear material compounds remain-
investigation of material distributions within a facility, which
ing as holdup in nuclear facilities. Holdup occurs in all
could include potentially large holdup surface areas. Nuclear
facilities in which nuclear material is processed. Material may
material held up in pipes, ductwork, gloveboxes, and heavy
exist,forexample,inprocessequipment,inexhaustventilation
equipment is usually distributed in a diffuse and irregular
systems, and in building walls and floors.
manner. It is difficult to define the measurement geometry,
1.1.1 The most frequent uses of passive neutron holdup
identify the form of the material, and measure it.
techniques are for the measurement of uranium or plutonium
deposits in processing facilities. 1.6 Units—The values stated in SI units are to be regarded
as the standard. No other units of measurement are included in
1.2 This guide includes information useful for management,
this standard.
planning, selection of equipment, consideration of
1.7 This standard does not purport to address all of the
interferences, measurement program definition, and the utili-
safety concerns, if any, associated with its use. It is the
zation of resources.
responsibility of the user of this standard to establish appro-
1.3 Counting modes include both singles (totals) or gross
priate safety and health practices and determine the applica-
counting and neutron coincidence techniques.
bility of regulatory limitations prior to use.
1.3.1 Neutron holdup measurements of uranium are typi-
callyperformedonneutronsemittedduring(α,n)reactionsand
2. Referenced Documents
spontaneous fission using singles (totals) or gross counting.
2
2.1 ASTM Standards:
While the method does not preclude measurement using
C1009 Guide for Establishing and Maintaining a Quality
coincidenceormultiplicitycountingforuranium,measurement
AssuranceProgramforAnalyticalLaboratoriesWithinthe
efficiency is generally not sufficient to permit assays in
Nuclear Industry
reasonable counting times.
C1455 Test Method for Nondestructive Assay of Special
1.3.2 For measurement of plutonium in gloveboxes, in-
Nuclear Material Holdup Using Gamma-Ray Spectro-
stalled measurement equipment may provide sufficient effi-
scopic Methods
ciency for performing counting using neutron coincidence
C1490 GuidefortheSelection,TrainingandQualificationof
techniques in reasonable counting times.
Nondestructive Assay (NDA) Personnel
1.4 The measurement of nuclear material holdup in process
C1592/C1592M Guide for Making Quality Nondestructive
equipment requires a scientific knowledge of radiation sources
Assay Measurements
and detectors, radiation transport, modeling methods,
C1673 Terminology of C26.10 NondestructiveAssay Meth-
calibration, facility operations, and uncertainty analysis. It is
ods
subject to the constraints of the facility, management, budget,
2.2 NRC Standard:
and schedule, plus health and safety requirements, as well as
NRC Regulatory Guide 5.23 In-Situ Assay of Plutonium
3
the laws of physics. This guide does not purport to instruct the
Residual Holdup
NDA practitioner on these principles.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
1
This guide is under the jurisdiction ofASTM Committee C26 on Nuclear Fuel contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Cycle and is the direct responsibility of Subcommittee C26.10 on Non Destructive Standards volume information, refer to the standard’s Document Summary page on
Assay. the ASTM website.
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Current edition approved Jan. 1, 2015. Published January 2015. DOI: 10.1520/ Available from U. S. Nuclear Regulatory Commission (NRC), OneWhite Flint
C1807-15. North, 11555 Rockville Pk., Rockville, MD 20852-2738, http://www.nrc.gov.
Copyright © ASTM International, 1
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