ASTM E525-90(1996)

Practice for Reporting Dosimetry Results on Nuclear Graphite (Withdrawn 2001)

SCOPE
1.1 This practice covers procedures for determining and reporting the neutron fluence rate and fluence for the correlation of radiation-induced changes in nuclear graphites.  
1.2 The purpose of this practice is to achieve better correlation and interpretation of new data in the field of radiation effects testing of specimens of graphites to be used for moderator or reflector components of fission reactors.  
1.3 Excluded from this practice are graphite test specimens containing fissionable materials and specimens containing materials having high neutron cross sections.

General Information

• Status: Withdrawn
• Publication Date: 31-Dec-1995
• Withdrawal Date: 09-Jan-2001
• ICS: 71.060.10 - Chemical elements
• Technical Committee: E10 - Nuclear Technology and Applications
• Drafting Committee: E10.05 - Nuclear Radiation Metrology

Relations

• Referred By: ASTM C625-15(2021) - Standard Practice for Reporting Irradiation Results on Graphite
• Effective Date: 01-Jan-1996

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: E 525 – 90 (Reapproved 1996)
Standard Practice for
Reporting Dosimetry Results on Nuclear Graphite
This standard is issued under the fixed designation E 525; 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 of graphite irradiation results is that developed by Thompson
and Wright (7).
1.1 This practice covers procedures for determining and
reporting the neutron fluence rate and fluence for the correla-
4. Exposure Unit for Graphite Irradiations
tion of radiation-induced changes in nuclear graphites.
4.1 The “Equivalent Fission Fluence for Damage in Graph-
1.2 The purpose of this practice is to achieve better corre-
ite,” F , is defined as follows:
G
lation and interpretation of new data in the field of radiation
effects testing of specimens of graphites to be used for F 5
G
‘ t
moderator or reflector components of fission reactors.
s ~E!p~E!f~E, t!dtdE
* *
s
0 t
1.3 Excluded from this practice are graphite test specimens
(1)
‘ ‘
containing fissionable materials and specimens containing s E p E x E dE/ x E dE
~ ! ~ ! ~ ! ~ !
* *
0 0
materials having high neutron cross sections.
where:
2. Referenced Documents
f(E, t) 5 neutron fluence rate spectrum at time t,
s (E) 5 scattering cross section of carbon as a function of
2.1 ASTM Standards:
s
C 625 Practice for Reporting Irradiation Results on Graph- neutron energy,
p(E) 5 atomic displacement weighting function,
ite
x(E) 5 spectrum for primary fission neutrons, and
E 261 Practice for Determining Neutron Fluence Rate, Flu-
t −t 5 duration of the irradiation test.
2 1
ence, and Spectra by Radioactivation Techniques
4.2 The two principal methods for obtaining neutron fluence
E 944 Guide for Application of Neutron Spectrum Adjust-
rate spectra are: (1) calculations using reactor physics codes (8,
ment Methods in Reactor Surveillance, (IIA)
9), and (2) computer-iterative techniques (see Guide E 944)
E 1018 Guide for Application of ASTM Evaluated Cross
using activation data from many different neutron detector
Section Data File (ENDF/A), E 706(IIB)
materials, simultaneously irradiated in the reactor facility. It is
3. Significance and Use
recommended that spectra obtained by either method be
checked by the activation of monitors having significantly
3.1 Practice C 625 covers information recommended for
different response functions.
inclusion in reports giving graphite irradiation results, with the
4.2.1 The response function, R (E), of an activation monitor
exception of neutron dosimetry results.
is defined as follows:
3.2 It is well documented (1,2,3) that mechanical proper-
‘
ties, physical properties, and physical dimensions of graphites
R~E!5s ~E!f~E!/ s ~E!f~E!dE (2)
a * a
are altered by exposure to high-energy neutron radiation and
that the amount, rate, and energy spectrum of the radiation
where:
influences the magnitude and relationship of the changes.
s (E) 5 activation cross section as a function of neutron
a
3.3 It is also well documented (4,5,6) that graphite irradia-
energy, and
tion results obtained at different dose rates or different energy
f(E) 5 fluence spectrum at the measurement location.
spectra, or both, can be adequately correlated through the use
4.2.2 Other considerations are discussed in Practice E 261
of appropriate atomic displacement functions. The function
and other methods covering the use of individual detectors.
that is most widely used for the correlation and interpretation
4.3 It is recommended that the fission spectrum, x(E), the
scattering cross section s (E) used in evaluating Eq 1, and all
s
cross sections used in the evaluation of the neutron fluence
This practice is under the jurisdiction of ASTM Committee E-10 on Nuclear
Technology and Applications and is the direct responsibility of Subcommittee
spectrum, be processed from the most recent edition of the
E10.05 on Nuclear Radiation Metrology.
Evaluated Nuclear Data File (10, Guide E 1018).
Current edition approved May 25, 1990. Published July 1990. Originally
4.4 An acceptable form of the atomic displacement weight-
published as E 525 – 74. Last previous edition E 525 – 74 (1981).
Annual Book of ASTM Standards, Vol 15.01.
ing function p(E) for evaluation of Eq 1 is the Thompson and
Annual Book of ASTM Standards, Vol 12.02.
Wright function. Group averaged values for this function are
The boldface numbers in parentheses refer to the references at the end of this
listed in Table 1 in the GAM-II energy group structure. Other
practice.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
E 525
A
TABLE 1 Group Averaged Values of the Thompson and Wright Atomic Displacement Weighting Function for Damage in Graphite
Group Upper Lower Displacement Group Upper Lower Displacement Group Upper Lower Displacement
B C
Number Energy, Lethargy Function Number Energy, Lethargy Function Number Energy, Lethargy Function
MeV MeV MeV
1 14.918 0.10 548.4 26 1.2246 2.60 317.6 51 86.517 5.40 1.2
2 13.499 0.20 540.6 27 1.1080 2.70 306.9 52 67.379 5.65 49.7
3 12.214 0.30 532.7 28 1.0026 2.80 296.1 53 52.475 5.90 40.2
4 11.052 0.40 524.7 29 0.90718 2.90 285.2 54 40.868 6.15 32.3
5 10.000 0.50 516.5 30 0.82085 3.00 274.2 55 31.828 6.40 25.9
6 9.0484 0.60 508.2 31 0.74274 3.10 262.9 56 24.788 6.65 20.7
7 8.1873 0.70 499.8 32 0.67206 3.20 251.5 57 19.305 6.90 16.5
8 7.4082 0.80 491.5 33 0.60810 3.30 240.5 58 15.034 7.15 13.1
9 6.7032 0.90 482.9 34 0.55023 3.40 229.2 59 11.709 7.40 10.3
10 6.0653 1.00 474.1 35 0.49787 3.50 218.1 60 9.1188 7.65 8.0
11 5.4881 1.10 465.3 36 0.45049 3.60 207.3 61 7.1017 7.90 6.2
12 4.9659 1.20 456.3 37 0.40762 3.70 196.7 62 5.5308 8.15 4.8
13 .4.4933 1.30 447.2 38 0.36883 3.80 186.3 63 4.3074 8.40 3.7
14 4.0657 1.40 437.6 39 0.33373 3.90 176.1 64 3.3546 8.65 2.9
15 3.6788 1.50 428.2 40 0.30197 4.00 166.2 65 2.6126 8.90 2.3
16 3.3287 1.60 418.7 41 0.27324 4.10 156.5 66 2.0347 9.15 1.8
17 3.0119 1.70 409.1 42 0.24724 4.20 147.0 67 1.5846 9.40 1.4
18 2.7253 1.80 399.4 43 0.22371 4.30 137.8 68 1.2341 9.65 1.1
19 2.4660 1.90 389.6 44 0.20242 4.40 128.8 69 0.96112 9.90 0.8
20 2.2313 2.00 379.7 45 0.18316 4.50 120.0 70 0.74852 10.15 0.6
21 2.0190 2.10 369.6 46 0.16573 4.60 111.5 71 0.58295 10.40 0.5
22 1.8268 2.20 359.4 47 0.14966 4.70 103.2 72 0.45400 10.65 0.4
23 1.6530 2.30 349.1 48 0.13569 4.80 95.2 73 0.35358 10.90 0.3
24 1.4957 2.40 338.7 49 0.12277 4.90 87.4 74 0.27536 11.15 0.2
D
25 1.3534 2.50 328.2 50 0.11109 5.15 74.8 75 0.21445 1
...