ASTM C1493-09
(Test Method)Standard Test Method for Non-Destructive Assay of Nuclear Material in Waste by Passive and Active Neutron Counting Using a Differential Die-Away System (Withdrawn 2018)
Standard Test Method for Non-Destructive Assay of Nuclear Material in Waste by Passive and Active Neutron Counting Using a Differential Die-Away System (Withdrawn 2018)
SIGNIFICANCE AND USE
This test method is useful for quantifying fissile (for example, 233U, 235U, 239Pu and 241Pu) and spontaneously-fissioning nuclei (for example, 238Pu, 240Pu, 242Pu, 244Cm, 248Cm, and 252Cf) in waste and scrap drums. Total elemental mass of the radioactive materials can be calculated if the relative abundances of each radionuclide are known.
Typically, this test method is used to measure one fissile isotope (for example, 235U or 239Pu).
This test method can be used to segregate low level and transuranic waste at the 100 nCi/g concentration level currently required to meet the DOE Waste Isolation Pilot Plant (WIPP) waste acceptance criterion (5, 8, 9).
This test method can be used for waste characterization to demonstrate compliance with the radioactivity levels specified in waste, disposal, and environmental regulations (See NRC regulatory guides, DOE Order 435.1, 10 CFR Part 71, 40 CFR Part 191, and DOE /WIPP-069).
In the active mode, the DDT system can measure the 235U content in the range from 0.02 to >100 g and the 239Pu content, nominally between 0.01 and >20 g.
In the passive mode, the DDT system is capable of assaying spontaneously-fissioning nuclei, over a nominal range from 0.05 to 15 g of 240Pu, or equivalent (5, 10, 11, 12, 13).
This test method should be used in conjunction with a waste management plan that segregates the contents of assay items into material categories according to some or all of the following criteria: bulk density of the waste, chemical forms of the plutonium or uranium and matrix, (α, n) neutron intensity, hydrogen (moderator) and absorber content, thickness of fissile mass(es), and the assay item container size and composition. Each matrix may require a different set of calibration standards and may have different mass calibration limits. The effect on the quality of the assay (that is, minimizing precision and bias) can significantly depend on the degree of adherence to this waste management plan.
The bias of the measu...
SCOPE
1.1 This test method covers a system that performs nondestructive assay (NDA) of uranium or plutonium, or both, using the active, differential die-away technique (DDT), and passive neutron coincidence counting. Results from the active and passive measurements are combined to determine the total amount of fissile and spontaneously-fissioning material in drums of scrap or waste. Corrections are made to the measurements for the effects of neutron moderation and absorption, assuming that the effects are averaged over the volume of the drum and that no significant lumps of nuclear material are present. These systems are most widely used to assay low-level and transuranic waste, but may also be used for the measurement of scrap materials. The examples given within this test method are specific to the second-generation Los Alamos National Laboratory (LANL) passive-active neutron assay system.
1.1.1 In the active mode, the system measures fissile isotopes such as 235U and 239Pu. The neutrons from a pulsed, 14-MeV neutron generator are thermalized to induce fission in the assay item. Between generator pulses, the system detects prompt-fission neutrons emitted from the fissile material. The number of detected neutrons between pulses is proportional to the mass of fissile material. This method is called the differential die-away technique.
1.1.2 In the passive mode, the system detects time-coincident neutrons emitted from spontaneously fissioning isotopes. The primary isotopes measured are 238Pu, 240Pu, and 242Pu; however, the system may be adapted for use on other spontaneously-fissioning isotopes as well, such as kilogram quantities of 238U. The number of coincident neutrons detected is proportional to the mass of spontaneously-fissioning material.
1.2 The active mode is used to assay fissile material in the following ranges.
1.2.1 For uranium-only bearing items, the DDT can measure the 235U content in the range from abo...
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Designation: C1493 − 09
Standard Test Method for
Non-Destructive Assay of Nuclear Material in Waste by
Passive and Active Neutron Counting Using a Differential
1
Die-Away System
This standard is issued under the fixed designation C1493; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.2.1 For uranium-only bearing items, the DDT can mea-
235
sure the U content in the range from about 0.02 to over 100
1.1 This test method covers a system that performs nonde-
g. Small mass uranium-bearing items are typically measured
structiveassay(NDA)ofuraniumorplutonium,orboth,using
using the active mode and only large mass items are measured
the active, differential die-away technique (DDT), and passive
in passive mode.
neutron coincidence counting. Results from the active and
1.2.2 For plutonium-only bearing items, the DDT method
passive measurements are combined to determine the total
239
measures the Pu content in the range between about 0.01
amount of fissile and spontaneously-fissioning material in
and 20 g.
drums of scrap or waste. Corrections are made to the measure-
ments for the effects of neutron moderation and absorption,
1.3 Thepassivemodeiscapableofassayingspontaneously-
240
assuming that the effects are averaged over the volume of the
fissioningnuclei,overanominalrangefrom0.05to15g Pu
drum and that no significant lumps of nuclear material are
equivalent.
present.Thesesystemsaremostwidelyusedtoassaylow-level
1.4 This test method requires knowledge of the relative
and transuranic waste, but may also be used for the measure-
abundances of the plutonium or uranium isotopes to determine
ment of scrap materials. The examples given within this test
the total plutonium or uranium mass.
method are specific to the second-generation Los Alamos
National Laboratory (LANL) passive-active neutron assay
1.5 Thistestmethodwillgivebiasedresultswhenthewaste
system.
form does not meet the calibration specifications and the
1.1.1 In the active mode, the system measures fissile iso-
measurementassumptionspresentedinthistestmethodregard-
235 239
topes such as U and Pu. The neutrons from a pulsed,
ing the requirements for a homogeneous matrix, uniform
14-MeVneutron generator are thermalized to induce fission in
source distribution, and the absence of nuclear material lumps,
the assay item. Between generator pulses, the system detects
to the extent that they effect the measurement.
prompt-fission neutrons emitted from the fissile material. The
1.6 The complete active and passive assay of a 208 Ldrum
number of detected neutrons between pulses is proportional to
isnominally10minorlessbuteithermodecanbeextendedto
the mass of fissile material. This method is called the differ-
meet data quality objectives.
ential die-away technique.
1.1.2 In the passive mode, the system detects time-
1.7 Some improvements to this test method have been
2
coincident neutrons emitted from spontaneously fissioning
reported (1, 2, 3, 4). Discussions of these improvements are
238 240
isotopes. The primary isotopes measured are Pu, Pu,
not included in this test method although improvements
242
and Pu; however, the system may be adapted for use on
continue to occur.
other spontaneously-fissioning isotopes as well, such as kilo-
238 1.8 The values stated in SI units are to be regarded as
gram quantities of U. The number of coincident neutrons
standard. No other units of measurement are included in this
detected is proportional to the mass of spontaneously-
standard.
fissioning material.
1.9 This standard may involve hazardous materials,
1.2 The active mode is used to assay fissile material in the
operations, and equipment. This standard does not purport to
following ranges.
address all of the safety concerns, if any, associated with its
use. It is the responsibility of the user of this standard to
1
ThistestmethodisunderthejurisdictionofASTMCommitteeC26onNuclear
Fuel Cycle and is the direct responsibility of Subcommittee C26.10 on Non
Destructive Assay.
Current edition approved Feb. 1, 2009. Published March 2009. Originally
2
approved in 2001. Last previous edition approved in 2001 as C1493–01. DOI: The boldface numbers given in parentheses refer to a list of references at the
10.1520/C1493-09. end of the text.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
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C1493 − 09
establish appropriate safety and health practices and deter- in the chamber and in the assay item. Thermal neutrons are
mine the applicability of regulatory limitations p
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:C1493–01 Designation: C 1493 – 09
Standard Test Method for
Non-Destructive Assay of Nuclear Material in Waste by
Passive and Active Neutron Counting Using a Differential
1
Die-Away System
This standard is issued under the fixed designation C 1493; 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
1.1 This test method covers a system that performs nondestructive assay (NDA) of uranium or plutonium, or both, using the
active, differential die-away technique (DDT), and passive neutron coincidence counting. Results from the active and passive
measurements are combined to determine the total amount of fissile and spontaneously-fissioning material in drums of scrap or
waste as large as 208 L. waste. Corrections are made to the measurements for the effects of neutron moderation and absorption,
assuming that the effects are averaged over the volume of the drum and that no significant lumps of nuclear material are present.
These systems are most widely used to assay low-level and transuranic waste, but may also be used for the measurement of scrap
materials. While The examples given within this test method isare specific to the second-generation Los Alamos National
Laboratory (LANL) passive-active neutron assay system, the principle applies to other DDT systems. system.
235 239
1.1.1 In the active mode, the system measures fissile isotopes such as U and Pu. The neutrons from a pulsed, 14-MeV
neutron generator are thermalized to induce fission in the assay item. Between generator pulses, the system detects prompt-fission
neutrons emitted from the fissile material. The number of detected neutrons between pulses is proportional to the mass of fissile
material. This method is called the differential die-away technique.
1.1.2 In the passive mode, the system detects time-coincident neutrons emitted from spontaneously fissioning isotopes. The
238 240 242
primary isotopes measured are Pu, Pu, and Pu; however, the system may be adapted for use on other spontaneously-
238
fissioning isotopes as well, such as kilogram quantities of U. The number of coincident neutrons detected is proportional to the
mass of spontaneously-fissioning material.
1.2 The active mode is used to assay fissile material in the following ranges.
235
1.2.1 For uranium-only bearing items, the DDT can measure the U content in the range from 0.02 to over 100 g. Normally,
the assay of items bearing only uranium is performed using matrix-specific calibrations to account for the effect of the matrix on
the active signal.
U content in the range from about 0.02 to over 100 g. Small mass uranium-bearing
1.2.2Forplutonium-bearingitems,theDDTmethodmeasuresthe
items are typically measured using the active mode and only large mass items are measured in passive mode.
239
1.2.2 For plutonium-only bearing items, the DDT method measures the Pu content in the range between about 0.01 and 20
g.
240
1.3 The passive mode is capable of assaying spontaneously-fissioning nuclei, over a nominal range from 0.05 to 15 g ofg Pu,
238
or equivalent. The passive mode can also be used to measure large (for example, kg) quantities of U. Pu equivalent.
1.4 This test method requires knowledge of the relative abundances of the plutonium or uranium isotopes to determine the total
plutonium or uranium mass.
1.5 This test method will give biased results when the waste form does not meet the calibration specifications and the
measurement assumptions presented in this test method regarding the requirements for a homogeneous matrix, uniform source
distribution, and the absence of nuclear material lumps, to the extent that they effect the measurement.
1.6The complete active and passive assay of a 208 L drum is nominally 10 min or less.
1.7Improvements to this test method have been reported
1.6 Thecompleteactiveandpassiveassayofa208Ldrumisnominally10minorlessbuteithermodecanbeextendedtomeet
data quality objectives.
1
This test method is under the jurisdiction ofASTM Committee C26 on Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.10 on Non-Destructive
Assay.
Current edition approved Feb. 10, 2001. Published May 2001.
1
This test method is under the jurisdiction ofASTM Committee C26 on Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.10 on Non Destructive
Assay.
Curren
...
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