ASTM E526-97(2002)

Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Titanium

SCOPE
1.1 This test method covers procedures for measuring reaction rates by the activation reactions 46Ti (n, p) 46Sc + 47Ti (n, np) 46Sc.
Note 1—Since the cross section for the (n,np) reaction is relatively small for energies less than 12 MeV and is not easily distinguished from that of the (n,p) reaction, this test method will refer to the (n,p) reaction only.
1.2 The reaction is useful for measuring neutrons with energies above approximately 4.4 MeV and for irradiation times up to about 250 days (for longer irradiations, see Practice E 261).
1.3 With suitable techniques, fission-neutron fluence rates above 109  cm-2s-1  can be determined. However, in the presence of a high thermal-neutron fluence rate, 46Sc depletion should be investigated.
1.4 Detailed procedures for other fast-neutron detectors are referenced in Practice E 261.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Jun-1997
• ICS: 17.240 - Radiation measurements
• ICS: 27.120.30 - Fissile materials and nuclear fuel technology
• Technical Committee: E10 - Nuclear Technology and Applications
• Drafting Committee: E10.05 - Nuclear Radiation Metrology

Relations

• Replaces: ASTM E526-97 - Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Titanium
• Effective Date: 10-Jun-1997
• Replaced By: ASTM E526-08 - Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Titanium
• Effective Date: 01-Jul-2008
• Referred By: ASTM E1854-19 - Standard Practice for Ensuring Test Consistency in Neutron-Induced Displacement Damage of Electronic Parts
• Effective Date: 10-Jun-1997
• Referred By: ASTM E1005-21 - Standard Test Method for Application and Analysis of Radiometric Monitors for Reactor Vessel Surveillance
• Effective Date: 10-Jun-1997
• Referred By: ASTM E944-19 - Standard Guide for Application of Neutron Spectrum Adjustment Methods in Reactor Surveillance
• Effective Date: 10-Jun-1997
• Referred By: ASTM E261-16(2021) - Standard Practice for Determining Neutron Fluence, Fluence Rate, and Spectra by Radioactivation Techniques
• Effective Date: 10-Jun-1997
• Referred By: ASTM E721-22 - Standard Guide for Determining Neutron Energy Spectra from Neutron Sensors for Radiation-Hardness Testing of Electronics
• Effective Date: 10-Jun-1997
• Referred By: ASTM E2005-21 - Standard Guide for Benchmark Testing of Reactor Dosimetry in Standard and Reference Neutron Fields
• Effective Date: 10-Jun-1997

Standards Content (Sample)

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
Designation:E526–97 (Reapproved 2002)
Standard Test Method for
Measuring Fast-Neutron Reaction Rates by Radioactivation
of Titanium
This standard is issued under the fixed designation E 526; 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.
1. Scope E 944 Guide for Application of Neutron Spectrum Adjust-
ment Methods in Reactor Surveillance, (IIA)
1.1 This test method covers procedures for measuring reac-
46 46 47
E 1005 Test Method forApplication andAnalysis of Radio-
tion rates by the activation reactions Ti (n, p) Sc + Ti (n,
metric Monitors for Reactor Vessel Surveillance, E 706
np) Sc.
(IIIA)
NOTE 1—Since the cross section for the (n,np) reaction is relatively
E 1018 Guide for Application of ASTM Evaluated Cross
small for energies less than 12 MeV and is not easily distinguished from
Section Data Files, Matrix E 706 (IIB)
that of the (n,p) reaction, this test method will refer to the (n,p) reaction
only.
3. Terminology
1.2 The reaction is useful for measuring neutrons with
3.1 Definitions:
energies above approximately 4.4 MeV and for irradiation
3.1.1 Refer to Terminology E 170.
timesuptoabout250days(forlongerirradiations,seePractice
E 261).
4. Summary of Test Method
1.3 With suitable techniques, fission-neutron fluence rates
4.1 High-purity titanium is irradiated in a fast-neutron field,
9 –2 –1
46 46 46
above 10 cm ·s can be determined. However, in the pres-
thereby producing radioactive Sc from the Ti (n, p) Sc
ence of a high thermal-neutron fluence rate, Sc depletion
activation reaction.
should be investigated.
4.2 Thegammaraysemittedbytheradioactivedecayof Sc
1.4 Detailed procedures for other fast-neutron detectors are
arecountedinaccordancewithMethodsE 181andthereaction
referenced in Practice E 261.
rate, as defined by Test Method E 261, is calculated from the
1.5 This standard does not purport to address all of the
decay rate and the irradiation conditions.
safety concerns, if any, associated with its use. It is the
4.3 The neutron fluence rate above about 4.4 MeV can then
responsibility of the user of this standard to establish appro-
be calculated from the spectral-weighted neutron activation
priate safety and health practices and determine the applica-
cross section as defined by Test Method E 261.
bility of regulatory limitations prior to use.
5. Significance and Use
2. Referenced Documents
5.1 Refer to Guide E 844 for the selection, irradiation, and
2.1 ASTM Standards:
quality control of neutron dosimeters.
E 170 Terminology Relating to Radiation Measurements
5.2 Refer to Test Method E 261 for a general discussion of
and Dosimetry
the determination of fast-neutron fluence rate with threshold
E 181 Test Methods for Detector Calibration and Analysis
detectors.
of Radionuclides
5.3 Titanium has good physical strength, is easily fabri-
E 261 Practice for Determining Neutron Fluence Rate, Flu-
cated, has excellent corrosion resistance, has a melting tem-
ence, and Spectra by Radioactivation Techniques
perature of 1675°C, and can be obtained with satisfactory
E 262 Test Method for Determining Thermal Neutron Re-
purity.
46 46
action and Fluence Rates by Radioactivation Techniques 3 4
5.4 Schasahalf-lifeof83.81days. The Scdecay emits
E 844 Guide for Sensor Set Design and Irradiation for
a 0.8893 MeV gamma 99.984 % of the time and a second
Reactor Surveillance, E 706 (IIC)
gamma with an energy of 1.1205 MeV 99.987 % of the time.
This test method is under the jurisdiction ofASTM Committee E10 on Nuclear
Technology and Applications and is the direct responsibility of Subcommittee Nuclear Wallet Cards, National Nuclear Data Center, prepared by Jagdish K.
E10.05 on Nuclear Radiation Metrology. Tuli, July 1990.
Current edition approved June 10, 1997. Published May 1998. Originally Evaluated Nuclear Structure Data File (ENSDF), maintained by the National
published as E 526 – 76. Last previous edition E 526 – 92. Nuclear Data Center (NNDC), Brookhaven National Laboratory, on behalf of the
Annual Book of ASTM Standards, Vol 12.02. International Network for Nuclear Structure Data Evaluation.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E526
5.5 The isotopic content of natural titanium recommended 6.2 Precision Balance, able to achieve the required accu-
46 5
for Ti is 8.012 %. racy.
5.6 The radioactive products of the neutron 6.3 Digital Computer, useful for data analysis (optional).
47 47 48 48
1 1
reactions Ti(n,p) Sc(T ⁄2= 3.35 d) and Ti(n,p) Sc(T ⁄2 =
46 7. Materials
1.82 d), might interfere with the analysis of Sc.
65 182
7.1 Titanium Metal—High-puritytitaniummetalintheform
5.7 Contaminant activities (for example, Zn and Ta)
of wire or foil is available.
might interfere with the analysis of Sc. See Section 7.1.2 and
182 65
7.1.1 The metal should be tested for impurities by a neutron
7.1.3 or more details on the Ta and Zn interference.
46 46
activation technique. If the measurement is to be made in a
5.8 Ti and Sc have cross sections for thermal neutrons of
thermal-neutron environment, scandium impurity must be low
0.6 and 8 barns, respectively; therefore, when an irradiation
45 46
because of the reaction, Sc (n,g) Sc. To reduce this interfer-
exceeds a thermal-neutron fluence greater than about 23 10
–2
ence, the use of a thermal-neutron shield during irradiation
cm , provisions should be made to either use a thermal-
would be advisable if scandium impurity is suspected. As an
neutron shield to prevent burnup of Sc or measure the
example, when a titanium sample containing 6 ppm scandium
thermal-neutron fluence rate and calculate the burnup.
has been irradiated in a neutron field with equal thermal and
5.9 Fig. 1 shows a plot of cross section versus neutron
energy for the fast-neutron reactions of titanium which fast-neutron fluence rates about 1 % of the Sc in the sample is
45 46
46 Nat 46
due to the reaction Sc (n,g) Sc.
produce Sc (that is, Ti(n,X) Sc). Included in the plot is
46 47 46
the Ti(n,p) reaction and the Ti(n,np) contribution to the Sc 7.1.2 Tantalum impurities can also cause a problem. The
181 182
8 9 46
low-energy response of the Ta(n,g) Ta reaction produces
production, normalized (to 14.7 MeV) per Ti atom. This
figure is for illustrative purposes only to indicate the range of gamma activity that interferes with the measurement of Sc
46 46
radioactivity produced from the Ti(n,p) Sc high-energy
response of the Ti(n,p) reaction. Refer to Guide E 1018 for
descriptions of recommended tabulated dosimetry cross sec- threshold reaction. The radioactive Ta isotope has a half-life
of t = 114.43 d and emits a 1121.302 keV photon 34.7 % of
tions.
1/2
the time. This photon is very close in energy to one of the two
6. Apparatus
photons emitted by Sc (889.3 keV and 1120.5 keV). More-
over, during the Sc decay, the 1120.5 keV and 889.3 keV
6.1 NaI(Tl) or High Resolution Gamma-Ray Spectrometer.
photons are emitted in true coincidence and the random
Because of its high resolution, the germanium detector is
coincidence between the 1121.302 keV photons from Ta and
useful when contaminant activities are present. See Methods
the 889.3 keV photons from Sc can affect the application of
E 181 and E 1005.
summing corrections when the counting is done in a close
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