ASTM C1673-07
(Terminology)Standard Terminology of C26.10 Nondestructive Assay Methods
Standard Terminology of C26.10 Nondestructive Assay Methods
SCOPE
1.1 The terminology defined in this document is associated with nondestructive assay of nuclear material.
1.2 All of the definitions are associated with measurement techniques that measure nuclear emissions (that is, neutrons, gamma-rays, or heat) directly or indirectly.
1.3 definitions are relevant to any standards and guides written by subcommittee C26.10.
General Information
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Standards Content (Sample)
Designation:C1673–07
Standard Terminology of
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C26.10 Nondestructive Assay Methods
This standard is issued under the fixed designation C 1673; 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 (e) indicates an editorial change since the last revision or reapproval.
typically from intense low-energy X or gamma rays.
1. Scope
1.1 The terminology defined in this document is assoc iated
accidentals, n—the detection of multiple neutron events
with nondestructive assay of nuclear material.
within the gate width that are not produced from the same
1.2 All of the definitions are associated with measurement
fission.
techniques that measure nuclear emissions (that is, neutrons,
DISCUSSION—Accidental events take their name from the fact that it
gamma-rays, or heat) directly or indirectly.
is the accidental or random summing of neutrons, which are not time
1.3 definitions are relevant to any standards and guides
correlated with a common origin (fission or cosmic-ray burst), that give
written by subcommittee C26.10.
rise to the appearance of a signature like that from genuine correlated
events.
2. Referenced Documents
accuracy,n—(1) bias;(2) the closeness of a measured value to
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2.1 ASTM Standards:
the true value; and (3) the closeness of a measured value to
E 456 Terminology Relating to Quality and Statistics
an accepted reference or standard value.
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2.2 DOE Orders:
active assay,n—assay based on the observation of radiation(s)
DOE Order 435.1 Low-level Waste Requirements
induced by irradiation from an external source.
DOE Order 5820.2 Radioactive Waste Management
alpha, a, n—the ratio of the uncorrelated neutron emission
rate from (,n) reactions to the spontaneous neutron emission
3. Terminology
rate from a non-multiplying item.
(alpha) reaction, n—a reaction that occurs when energetic
aperture, n—the size of the opening in the collimator through
alpha particles collide with low atomic number nuclei
which the radiation of interest is intended to pass.
resulting in the emission of a neutron
assay, v—to determine quantitatively the amount of one or
240 240
Pu-effective mass, n—the mass of Pu that would produce
more nuclides of interest contained in an item.
the same coincident neutron response in the instrument as
attenuation correction, n—correction to the measured count
the assay item.
rate for attenuation of radiation that provides an estimate of
the unattenuated radiation emission rate of the radionuclides
DISCUSSION—It is a function of the quantity of even mass isotopes of
plutonium in the assay item and fundamental nuclear constants, being assayed.
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sometimes referred to as effective Pu mass.
attenuation, n—reduction of radiation flux due to the interac-
tion of radiation with material between the source of the
absorber foils, n—foils, usually of copper, tin, cadmium, or
radiation and the detector.
lead, used to attenuate the gamma flux reaching a detector.
background,n—extraneoussignalsuperimposedonthesignal
DISCUSSION—Absorber foils are used to reduce the count rate,
of interest.
Beers Law, n—the fraction of uncollided gamma rays trans-
1 mitted through layers of equal thickness of an absorber is a
ThisterminologyisunderthejurisdictionofASTMCommitteeC26onNuclear
constant.
Fuel Cycle and is the direct responsibility of Subcommittee C26.10 on Non
Destructive Assay.
benign matrix, n—material that has a negligible effect on the
Current edition approved June 1, 2007. Published July 2007.
result of the measured parameter.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or
blank, n—a prepared item containing a matrix as similar as
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on practical to the items being measured that is free, to the
the ASTM website.
extent possible, of the radionuclides of interest.
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Available from the U.S. Department of Energy (DOE), 1000 Independence
Ave., SW Washington, DC 20585.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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C1673–07
DISCUSSION—The most important matrix parameters are those that
data quality objective, n—measurement uncertainty and con-
affect the result of the measurement technique being used.
fidence levels specified by the scope of work.
dead time, n—the period following the detection of an event
calibration standard, n—an item similar to the items to be
during which the detection electronics cannot register a
assayed, for which the parameters of interest and all prop-
subsequent event.
erties to which the measurement technique is sensitive are
known.
DISCUSSION—Dead time is usually expressed as a percentage of
calorimeter, n—a device to measure he
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