ASTM C1673-07e1

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
´1
Designation:C1673–07
Standard Terminology of
1
C26.10 Nondestructive Assay Methods
This standard is issued under the fixed designation C1673; 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
´ NOTE—Corrections were made throughout editorially in October 2007.
DISCUSSION—Absorber foils are used to reduce the count rate,
1. Scope
typically from intense low-energy X or gamma rays.
1.1 The terminology defined in this document is associated
with nondestructive assay of nuclear material. accidentals, n—the detection of multiple neutron events
1.2 All of the definitions are associated with measurement within the gate width that are not produced from the same
techniques that measure nuclear emissions (that is, neutrons, fission.
gamma-rays, or heat) directly or indirectly.
DISCUSSION—Accidental events take their name from the fact that it
1.3 definitions are relevant to any standards and guides
is the accidental or random summing of neutrons, which are not time
written by subcommittee C26.10.
correlated with a common origin (fission or cosmic-ray burst), that give
rise to the appearance of a signature like that from genuine correlated
2. Referenced Documents
events.
2
2.1 ASTM Standards:
accuracy,n—(1) bias;(2) the closeness of a measured value to
E456 Terminology Relating to Quality and Statistics
the true value; and (3) the closeness of a measured value to
3
2.2 DOE Orders:
an accepted reference or standard value.
DOE Order 435.1 Low-level Waste Requirements
active assay,n—assay based on the observation of radiation(s)
DOE Order 5820.2 Radioactive Waste Management
induced by irradiation from an external source.
alpha, a, n—the ratio of the uncorrelated neutron emission
3. Terminology
rate from (a, n) reactions to the spontaneous neutron
(alpha, n) reaction, n—a reaction that occurs when energetic
emission rate from a non-multiplying item.
alpha particles collide with low atomic number nuclei
aperture, n—the size of the opening in the collimator through
resulting in the emission of a neutron
which the radiation of interest is intended to pass.
240 240
Pu-effective mass, n—the mass of Pu that would pro-
assay, v—to determine quantitatively the amount of one or
duce the same coincident neutron response in the instrument
more nuclides of interest contained in an item.
as the assay item.
attenuation correction, n—correction to the measured count
rate for attenuation of radiation that provides an estimate of
DISCUSSION—It is a function of the quantity of even mass isotopes of
the unattenuated radiation emission rate of the radionuclides
plutonium in the assay item and fundamental nuclear constants,
240
sometimes referred to as effective Pu mass. being assayed.
attenuation, n—reduction of radiation flux due to the interac-
absorber foils, n—foils, usually of copper, tin, cadmium, or
tion of radiation with material between the source of the
lead, used to attenuate the gamma flux reaching a detector.
radiation and the detector.
background,n—extraneoussignalsuperimposedonthesignal
1
of interest.
ThisterminologyisunderthejurisdictionofASTMCommitteeC26onNuclear
Fuel Cycle and is the direct responsibility of Subcommittee C26.10 on Non Beers Law, n—the fraction of uncollided gamma rays trans-
Destructive Assay.
mitted through layers of equal thickness of an absorber is a
Current edition approved June 1, 2007. Published July 2007. DOI: 10.1520/
constant.
C1673-07E01.
2
benign matrix,n—bulkmaterialthathasanegligibleeffecton
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
the result of the measured parameter.
Standards volume information, refer to the standard’s Document Summary page on
blank, n—a prepared item containing a matrix as similar as
the ASTM website.
3 practical to the items being measured that is free, to the
Available from the U.S. Department of Energy (DOE), 1000 Independence
Ave., SW Washington, DC 20585. extent possible, of the radionuclides of interest.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
´1
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 elect
...