10.3. SCALE Nuclear Data Covariance Library
A. Holcomb, D. Wiarda, M. L. Williams, G. Arbanas, and B. L. Broadhead
ABSTRACT
An updated cross section covariance library has been created for use with the sensitivity and uncertainty modules in SCALE 6.3. The data have been assembled from a variety sources, including high-fidelity covariance evaluations from ENDF/B-VIII.0 as well as approximate uncertainties obtained from a collaborative project performed by Brookhaven National Laboratory, Los Alamos National Laboratory, and Oak Ridge National Laboratory. This document describes the assumptions in generating the data, the library contents, and processing procedure for the SCALE 56-group and 252-group covariance libraries. The ENDF/B-VII.1 covariance libraries provided with SCALE 6.3 are identical to the libraries released with SCALE 6.2. The SCALE 44-group covariance library distributed with SCALE 6.0 and SCALE 6.1 is retained for backwards compatibility.
ACKNOWLEDGMENT
We gratefully acknowledge the sponsorship of the US Department of Energy Nuclear Criticality Safety Program in the development of the SCALE 6.3 covariance libraries.
10.3.1. Introduction
The SCALE 6.3 covariance library suite contains covariance libraries based on ENDF/B-VIII.0, ENDF/B-VII.1, and pre-ENDF/B-VII.0. For each ENDF release, if uncertainty information is not available for all neutron targets, then the corresponding SCALE covariance library is patched such that each library has some estimate of the uncertainty data for every neutron target in the library. The ENDF/B-VIII.0 covariance library [XSLibDAB18] contains at least some covariance data for 252 nuclides and the ENDF/B-VII.1 library [COVLIBCHO+11] has data for 187 nuclides. Both the ENDF/B-VIII.0 and ENDF/B-VII.1 covariance libraries have been supplemented by the previous SCALE 6.1 covariance data for the ~305 nuclides missing covariance data in ENDF/B-VIII.0 and ~215 nuclides missing covariance data in ENDF/B-VII.1. The ENDF/B-VII.1 uncertainties were modified for a few nuclides, as described in Sect. 10.3.2.3. The ENDF/B-VIII.0 covariance data are available in a 56-group format, and the ENDF/B-VII.1 covariance library is in both a 56-group and 252-group format. These covariance libraries were generated for compatibility with the ENDF/B-VII.1 cross section libraries distributed with SCALE 6.3, and they may also be applied for the 238-group ENDF/B-VII.0 library provided with SCALE 6.2. The previous SCALE 6.0 and SCALE 6.1 44-group library (44groupcov) was based on older covariance data and is retained in SCALE 6.3 for backwards compatibility. However, the 56- and 252-group covariance libraries (56groupcov7.1 and 252groupcov7.1) are now recommended for all applications. The 56-group library-which is default for SCALE uncertainty analysis-and the 252 fine-group library generally produce similar results, except for some threshold reactions such as (n,2n). The 252-group library may be used to improve uncertainty estimates from these types of data, but it takes more execution time than the default 56-group library. Because the 56- and 252-group covariance data in many cases are based on newer uncertainty evaluations than the previous 44-group library, some differences will occur between these sets of results.
The covariance data correspond to relative uncertainties assembled from a variety of sources, including evaluations from ENDF/B-VIII.0, ENDF/B-VII.1, ENDF/B-VI, and approximated uncertainties from a collaborative project performed by Brookhaven National Laboratory (BNL), Los Alamos National Laboratory (LANL), and Oak Ridge National Laboratory (ORNL). Because SCALE uncertainty data come from several different sources, the application of a single generic covariance library to all multigroup cross section libraries raises questions about consistency with any given data evaluation. In reality, much of the approximate uncertainty data in the library is based on simplifying approximations that do not depend on specific ENDF evaluations and thus can be applied to all cross section libraries within the limitations of the assumed methodology. In other cases in which a covariance evaluation has been taken from a specific nuclear data file (e.g., ENDF/B-VIII.-,ENDF/B-VII.1, ENDF/B-VI, or JENDL), it is assumed that the same relative (rather than absolute) uncertainties can be applied to all cross section libraries, even if these are not strictly consistent with the nuclear data evaluations. The assumption is partially justified by the fact that different evaluations often use many of the same experimental measurements since there is a limited amount of this information available. In some cases, older data evaluations have been carried over into the newer ENDF versions. Also, because many important nuclear data are now known rather well, newer evaluations in many instances correspond to rather modest variations from previous ones and are expected to lie within the earlier uncertainties.
No inherently “true” uncertainty can be defined for nuclear data. For example, in theory, two independent evaluations could produce similar nuclear data with very different uncertainties. Differences in nuclear data evaluations directly impact calculations that can be affirmed by comparisons with benchmark experiments; but there is no established procedure to quantify the reliability of uncertainty estimates. In general, the SCALE covariance library should be viewed as a best-estimate assessment of data uncertainties based upon the specific methodology described in the following section. While this methodology is not unique and other approaches could have been used, the SCALE covariance library is a reasonable representation of the nuclear data uncertainties for most applications given the current lack of information. Furthermore, it is the only available comprehensive library that has been created in a well-defined, systematic manner.
10.3.2. Covariance Data Description
10.3.2.1. Evaluated covariances from nuclear data files
A rigorous, modern evaluation of nuclear data typically uses a regression algorithm that adjusts parameters in a nuclear physics model (e.g., Reich-Moore resonance formula, optical model, etc.), to fit a set of differential experimental measurements that have various sources of statistical and systematic uncertainties [COVLIBLLD+06]. Information from the regression analysis of the model parameters can be propagated to uncertainties and correlations in the evaluated differential data. In this manner, the differential nuclear data and covariances are consistent and are coupled together by evaluation processes. Unfortunately, only a limited number of cross section evaluations have produced high-fidelity covariances in this rigorous manner. All other nuclear data uncertainties must be estimated from approximations in which the uncertainty assessment is decoupled from the original evaluation procedure.
The SCALE covariance library is based on several different uncertainty approximations with varying degrees of fidelity relative to the actual nuclear data evaluation. The library includes high-fidelity evaluated covariances obtained from the latest ENDF releases whenever available. As discussed in Sect. 10.3.1, it is assumed that covariances taken from one data evaluation, such as ENDF/B-VII.1, can also be applied to other evaluations of the same data, such as ENDF/B-VIII.0. If this is done judiciously for cases in which the nuclear data evaluations are similar, then the covariances taken from one source should be a reasonable representation of uncertainties for the other evaluations.
10.3.2.2. Approximate covariance data
At the other end of the spectrum from high fidelity data, low-fidelity (lo-fi) covariances are defined to be those estimated independently of a specific data evaluation. The approximate covariance data in SCALE are based on results from a collaborative project funded by the US Department of Energy Nuclear Criticality Safety Program to generate lo-fi covariances over the energy range from 10-5 eV to 20 MeV for materials without covariances in ENDF/B-VII.1. Nuclear data experts at BNL, LANL, and ORNL devised simple procedures to estimate data uncertainties in the absence of high fidelity covariance evaluations. The result of this project is a set of covariance data in ENDF/B file 33 format that can be processed into multigroup covariances [COVLIBLKH+08]. Some of these data were later revised and included in ENDF/B-VII.1, while others were carried over from SCALE 6.1 to the SCALE 6.3 library. In this documentation, these data are known as BLO (BNL-LANL-ORNL) uncertainty data, which were generated as described below.
ORNL used uncertainties in integral experiment measurements of thermal cross sections, resonance integrals, and potential cross sections to approximate the standard deviations of capture, fission, and elastic scattering reactions for the thermal (<0.5 eV) and resonance ranges (0.5 eV- 5 keV). Full energy correlation was assumed for the covariances within each of these respective ranges [COVLIBWBDR07, COVLIBWR08] This procedure was originally introduced for the approximate uncertainty data in SCALE 5.1. However, the current version includes updated integral measurement uncertainties, using the more recent values tabulated by Mughabghab in the Atlas of Neutron Resonances [COVLIBMug06]. The lo-fi relative uncertainty is computed as the absolute uncertainty in the integral parameter (i.e., thermal cross section or resonance integral) taken from the Atlas, divided by the average of the measured parameter and the calculated value computed from ENDF/B-VII differential data:
where:
U is the relative lo-fi uncertainty included in SCALE,
\(\Delta\)I is the absolute uncertainty in the integral measurement (obtained from Mughabghab), and
XI and XD are the measured and computed (from ENDF/B differential data) integral parameter values, respectively.
In some cases the integral measurement value from the Mughabghab Atlas6 and the corresponding value computed from the ENDF/B-VII differential evaluation are inconsistent-defined here as having a difference greater than two standard deviations in the measured and computed integral parameters. In these cases, the lo-fi relative standard deviation is defined as half the difference relative to the average of the measured and calculated values:
In some instances this expression may exceed 100%. For these cases, a 100% uncertainty was assigned. Also, the Atlas does not include uncertainties in integral measurements for several isotopes, which typically are not of great interest for most applications. In this case the integral uncertainty was defined as a +/-5 in the least significant digit for these materials; e.g., 1.23 is assign an uncertainty of +/- 5E-3.
BNL and LANL provided estimates in the fast energy range from 5 keV to 20 MeV for covariances of capture, fission, elastic, inelastic, (n,2n) cross sections, and prompt nubar. BNL used optical model calculations with estimated uncertainties in model parameters to compute covariances in the fast range for about 300 structural isotopes, fission products, and non-fissionable heavy nuclei. Estimated uncertainties in model parameters were based on previous work and expert judgment [COVLIBPHO09]. Covariances for 14 actinide isotopes were obtained from earlier work performed by BNL for Subgroup-26 (SG-26) [COVLIBRHOM07]. The SG-26 actinide covariances cover the full energy range, including thermal, resonance, and fast regions. If the thermal data uncertainties estimated by the SG-26 approach exceed the thermal uncertainty given in reference 6, the thermal data covariances are represented by ORNL’s integral uncertainty technique.
LANL produced covariances in the fast range for an additional 47 actinide materials. The LANL actinide covariances were based on empirical estimates of nuclear reaction models [COVLIBKTY+08]. Full energy range covariances were also produced by LANL for 16 light isotopes ranging from hydrogen to fluorine [COVLIBHal08]. These included high fidelity covariances from R-matrix analyses for 1H, 6Li, and 10B, along with lo-fi uncertainties for the other materials, based on approximations such as least-squares fitting to experimental data, statistical model calculations at higher energies, or sometimes simply best-judgment estimation [COVLIBLKH+08].
10.3.2.3. Modifications to covariance data
In generating earlier covariance libraries, some omissions or inconsistencies were identified and corrected in the current covariance library:
If the absolute correlation is larger than 1, it is set to 1.
If a relative uncertainty is larger than 1, it is set to 1.
If cross section data exist but covariance data do not span the entire range, then the diagonal element for the higher energy groups is repeated for the lower energy groups.
If total inelastic scattering covariance is not supplied, it is calculated from the uncertainties in the discrete level inelastic data.
If total nubar covariance is not supplied, it is calculated from the the prompt and delayed nubar uncertainties
A few inconsistencies were found in the ENDF/B-VII.1 uncertainty data, and these were modified for the SCALE 6.3 covariance library [COVLIBWIMR14]. The corrections were also conveyed to the National Nuclear Data Center, where they were added to the ENDF/A file for possible inclusion in the future release of ENDF/B-VIII.1. These modifications are summarized below:
235U thermal nubar: standard deviation was decreased from 0.7% to 0.3% in energy range from 0.0 to 0.5 eV, consistent with JENDL-3.3.
239Pu thermal nubar: standard deviation was increased from 0.01% to 0.15% in energy range from 0.0 to 0.01 eV, consistent with ENDF/B-VII.1 uncertainty at 0.01 eV.
H thermal capture: standard deviation reduced from 2.5% to 0.2%, consistent with Williams and Rearden 2008 [COVLIBWR08],
(d) 103Rh thermal capture: reduced from ~4% to 1.04%, consistent with Williams and Rearden 2008 [COVLIBWR08].
(e) 151Sm thermal capture: modified to ~1.8%, consistent with Williams and Rearden 2008 [COVLIBWR08].
(f) 147Pm: standard deviation was reduced from 24% to 5% in the energy range 0.5–5000 eV, consistent with the quoted resonance integral uncertainty in Williams and Rearden 2008 [COVLIBWR08].
Several modifications were also made to the uncertainties obtained from the original BLO data used in SCALE 6.1. The energy boundary between the thermal and resonance covariance blocks was modified from 0.5 to 0.625 eV in order to coincide with a 56-group boundary. The BLO lo-fi data do not include thermal or resonance range uncertainties for isotope reactions that do not have integral uncertainties given in the Mughabghab text [COVLIBMug06]. These occur mainly for relatively unimportant data such as elastic cross sections of several fission products. Therefore in these cases the uncertainties were estimated using different approaches. For example, the thermal data uncertainty was sometimes used to represent the epithermal uncertainty if it was not available in the Mughabghab tabulation, and sometimes the high-energy uncertainty was extended to lower energies. The uncertainty in the 149Sm resonance capture integral is not provided in the 2006 edition of Mughabghab’s text, so it was set to the value of 5.7%, which was obtained from an earlier tabulation by Mughabghab [COVLIBMug03].
10.3.2.4. Covariance data for fission spectra
As of ENDF/B-VII.1, covariance matrices are now provided for the fission exit energy distribution. The data are given as a function of incident energy. The incident energy grid is very broad, and the exit energy distribution is constant over a given incident energy group. Since the COVERX library file only allows one multigroup fission spectrum (\(\chi\)) covariance matrix per nuclide, the exit energy spectrum is used for the average energy of fission. If \(\nu\) is nubar, f is fission, and w is the appropriate flux, then the average energy of fission is calculated as:
where the sum is over all groups and Eg1 and Eg2 are the group boundaries for group g. ENDF/B-VII.1 provides covariance data for exit energy distributions for 64 nuclides. This includes all nuclides for which fission spectrum (\(\chi\)) covariance matrices where provided in the previous covariance library. Some additional \(\chi\)-covariance matrices were taken from JENDL-4.0. The new 56-group and 252-group fission spectrum covariances are more complete and significantly improved compared to the earlier 44-group chi uncertainty data, which were based on the Watt fission spectrum in ENDF/B-V. (see Sect. 10.3.5).
10.3.3. Multigroup Covariance Processing
Covariance data were processed with the AMPX code PUFF-IV [COVLIBWD06]. PUFF-IV has major improvements in the treatment of the resolved and unresolved resonance parameter uncertainties over previous code versions [COVLIBWALD08]. All nuclides with resonance parameter uncertainty files were processed with the full sensitivity option in PUFF-IV.
10.3.4. Contents of the SCALE 6.3 Covariance Library
The SCALE covariance library provides uncertainty data in 56- and 252-group formats for a total of 456 materials in ENDF/B-VII.1 and 587 materials in ENDF/B-VIII.0, including some duplication for materials with multiple thermal scattering kernels. Table 10.3.1 describes the contents of the library using the following nomenclature:
ENDF/B-VII.1: evaluated covariance data released with ENDF/B-VII.1
ENDF/B-VII.2-prelim: recently evaluated data proposed for future release of ENDF/B-VII.2
ENDF/B-VI: evaluated covariance data released with ENDF/B-VI
BLO approximate data: lo-fi covariances from BLO project
SG-26: approximate covariances from WPEC Subgroup-26
JENDL-4.0: evaluated covariance data released with JENDL-4.0
Several covariance evaluations include cross correlations between reactions. These are summarized in Table 10.3.2.
SCALE name |
SCALE ID |
Data source |
Comment |
|---|---|---|---|
ac-225 |
89225 |
ENDF/B-VII.1 |
|
ac-226 |
89226 |
ENDF/B-VII.1 |
|
ac-227 |
89227 |
ENDF/B-VII.1 |
|
ag-107 |
47107 |
BLO approximation data |
|
ag-109 |
47109 |
ENDF/B-VII.1 |
|
ag-110m |
1047110 |
BLO approximation data |
|
ag-111 |
47111 |
BLO approximation data |
|
al-27 |
13027 |
ENDF/B-VII.1 |
|
albound |
1013027 |
ENDF/B-VII.1 |
Duplicate of al-27 |
am-240 |
95240 |
ENDF/B-VII.1 |
|
am-241 |
95241 |
ENDF/B-VII.1 \(\chi\) covariance JENDL-4.0 |
|
am-242 |
95242 |
SG-26 \(\chi\) covariance JENDL-4.0 |
Thermal uncertainty replaced by Mughabghab value |
am-242m |
1095242 |
ENDF/B-VII.1 |
|
am-243 |
95243 |
ENDF/B-VII.1 \(\chi\) covariance JENDL-4.0 |
|
am-244 |
95244 |
BLO approximation data \(\chi\) covariance JENDL-4.0 |
|
am-244m |
1095244 |
BLO approximation data |
|
ar-36 |
18036 |
BLO approximation data |
|
ar-38 |
18038 |
BLO approximation data |
|
ar-40 |
18040 |
BLO approximation data |
|
as-74 |
33074 |
BLO approximation data |
|
as-75 |
33075 |
BLO approximation data |
|
au-197 |
79197 |
ENDF/B-VII.1 |
|
b-10 |
5010 |
ENDF/B-VII.1 |
|
b-11 |
5011 |
ENDF/B-VII.1 |
|
ba-130 |
56130 |
BLO approximation data |
|
ba-132 |
56132 |
BLO approximation data |
|
ba-133 |
56133 |
BLO approximation data |
|
ba-134 |
56134 |
BLO approximation data |
|
ba-135 |
56135 |
BLO approximation data |
|
ba-136 |
56136 |
BLO approximation data |
|
ba-137 |
56137 |
BLO approximation data |
|
ba-138 |
56138 |
BLO approximation data |
|
ba-140 |
56140 |
BLO approximation data |
|
be-7 |
4007 |
BLO approximation data |
|
be-9 |
4009 |
ENDF/B-VII.1 |
|
be-beo |
5004009 |
ENDF/B-VII.1 |
Duplicate of be-9 |
bebound |
3004009 |
ENDF/B-VII.1 |
Duplicate of be-9 |
bi-209 |
83209 |
ENDF/B-VII.1 |
|
bk-245 |
97245 |
ENDF/B-VII.1 |
|
bk-246 |
97246 |
ENDF/B-VII.1 |
|
bk-247 |
97247 |
ENDF/B-VII.1 |
|
bk-248 |
97248 |
ENDF/B-VII.1 |
|
bk-249 |
97249 |
ENDF/B-VII.1 |
|
bk-250 |
97250 |
ENDF/B-VII.1 |
|
br-79 |
35079 |
BLO approximation data |
|
br-81 |
35081 |
BLO approximation data |
|
c |
6000 |
ENDF/B-VII.1 |
|
ca |
20000 |
BLO approximation dataca |
|
ca-40 |
20040 |
BLO approximation data |
|
ca-42 |
20042 |
BLO approximation data |
|
ca-43 |
20043 |
BLO approximation data |
|
ca-44 |
20044 |
BLO approximation data |
|
ca-46 |
20046 |
BLO approximation data |
|
ca-48 |
20048 |
BLO approximation data |
|
cd |
48000 |
BLO approximation data |
|
cd-106 |
48106 |
BLO approximation data |
|
cd-108 |
48108 |
BLO approximation data |
|
cd-110 |
48110 |
BLO approximation data |
|
cd-111 |
48111 |
BLO approximation data |
|
cd-112 |
48112 |
BLO approximation data |
|
cd-113 |
48113 |
BLO approximation data |
|
cd-114 |
48114 |
BLO approximation data |
|
cd-115m |
1048115 |
BLO approximation data |
|
cd-116 |
48116 |
BLO approximation data |
|
ce-136 |
58136 |
BLO approximation data |
|
ce-138 |
58138 |
BLO approximation data |
|
ce-139 |
58139 |
BLO approximation data |
|
ce-140 |
58140 |
BLO approximation data |
|
ce-141 |
58141 |
ENDF/B-VII.1 |
|
ce-142 |
58142 |
BLO approximation data |
|
ce-143 |
58143 |
BLO approximation data |
|
ce-144 |
58144 |
BLO approximation data |
|
cf-246 |
98246 |
ENDF/B-VII.1 |
|
cf-248 |
98248 |
ENDF/B-VII.1 |
|
cf-249 |
98249 |
ENDF/B-VII.1 |
|
cf-250 |
98250 |
ENDF/B-VII.1 |
|
cf-251 |
98251 |
ENDF/B-VII.1 |
|
cf-252 |
98252 |
ENDF/B-VII.1 |
|
cf-253 |
98253 |
ENDF/B-VII.1 |
|
cf-254 |
98254 |
ENDF/B-VII.1 |
|
cl |
17000 |
BLO approximation data |
|
cl-35 |
17035 |
ENDF/B-VII.1 |
|
cl-37 |
17037 |
ENDF/B-VII.1 |
|
cm-240 |
96240 |
ENDF/B-VII.1 |
|
cm-241 |
96241 |
ENDF/B-VII.1 |
|
cm-242 |
96242 |
ENDF/B-VII.1 |
|
cm-243 |
96243 |
ENDF/B-VII.1 |
|
cm-244 |
96244 |
ENDF/B-VII.1 |
|
cm-245 |
96245 |
ENDF/B-VII.1 |
|
cm-246 |
96246 |
ENDF/B-VII.1 |
|
cm-247 |
96247 |
ENDF/B-VII.1 |
|
cm-248 |
96248 |
ENDF/B-VII.1 |
|
cm-249 |
96249 |
ENDF/B-VII.1 |
|
cm-250 |
96250 |
ENDF/B-VII.1 |
|
co-58 |
27058 |
BLO approximation data |
|
co-58m |
1027058 |
BLO approximation data |
|
co-59 |
27059 |
ENDF/B-VII.1 |
|
cr-50 |
24050 |
ENDF/B-VII.1 |
|
cr-52 |
24052 |
ENDF/B-VII.1 |
|
cr-53 |
24053 |
ENDF/B-VII.1 |
|
cr-54 |
24054 |
ENDF/B-VII.1 |
|
cs-133 |
55133 |
ENDF/B-VII.1 |
|
cs-134 |
55134 |
BLO approximation data |
|
cs-135 |
55135 |
ENDF/B-VII.1 |
|
cs-136 |
55136 |
BLO approximation data |
|
cs-137 |
55137 |
BLO approximation data |
|
cu-63 |
29063 |
ENDF/B-VI |
|
cu-65 |
29065 |
ENDF/B-VI |
|
d |
1002 |
ENDF/B-VII.1 |
Duplicate of h-2 |
d-cryo_ortho |
4001002 |
ENDF/B-VII.1 |
Duplicate of h-2 |
d-cryo_para |
5001002 |
ENDF/B-VII.1 |
Duplicate of h-2 |
dfreegas |
8001002 |
ENDF/B-VII.1 |
|
dy-156 |
66156 |
BLO approximation data |
|
dy-158 |
66158 |
BLO approximation data |
|
dy-160 |
66160 |
BLO approximation data |
|
dy-161 |
66161 |
BLO approximation data |
|
dy-162 |
66162 |
BLO approximation data |
|
dy-163 |
66163 |
BLO approximation data |
|
dy-164 |
66164 |
BLO approximation data |
|
er-162 |
68162 |
BLO approximation data |
|
er-164 |
68164 |
BLO approximation data |
|
er-166 |
68166 |
ENDF/B-VII.1 |
|
er-167 |
68167 |
ENDF/B-VII.1 |
|
er-168 |
68168 |
ENDF/B-VII.1 |
|
er-170 |
68170 |
ENDF/B-VII.1 |
|
es-251 |
99251 |
ENDF/B-VII.1 |
|
es-252 |
99252 |
ENDF/B-VII.1 |
|
es-253 |
99253 |
ENDF/B-VII.1 |
|
es-254 |
99254 |
ENDF/B-VII.1 |
|
es-254m |
1099254 |
ENDF/B-VII.1 |
|
es-255 |
99255 |
ENDF/B-VII.1 |
|
eu-151 |
63151 |
BLO approximation data |
|
eu-152 |
63152 |
BLO approximation data |
|
eu-153 |
63153 |
ENDF/B-VII.1 |
|
eu-154 |
63154 |
BLO approximation data |
|
eu-155 |
63155 |
ENDF/B-VII.1 |
Uses ENDF/B-VII.1 data uncertainty in the thermal range for MT=102 |
eu-156 |
63156 |
BLO approximation data |
|
eu-157 |
63157 |
BLO approximation data |
|
f-19 |
9019 |
ENDF/B-VII.1 |
|
fe-54 |
26054 |
ENDF/B-VII.1 |
|
fe-56 |
26056 |
ENDF/B-VII.1 |
|
fe-57 |
26057 |
ENDF/B-VII.1 |
|
fe-58 |
26058 |
ENDF/B-VI |
|
febound |
1026000 |
ENDF/B-VII.1 |
Duplicate of fe-56 |
fm-255 |
100255 |
ENDF/B-VII.1 |
|
ga |
31000 |
BLO approximation data |
|
ga-69 |
31069 |
BLO approximation data |
|
ga-71 |
31071 |
BLO approximation data |
|
gd-152 |
64152 |
ENDF/B-VII.1 |
|
gd-153 |
64153 |
ENDF/B-VII.1 |
|
gd-154 |
64154 |
ENDF/B-VII.1 |
|
gd-155 |
64155 |
ENDF/B-VII.1 |
|
gd-156 |
64156 |
ENDF/B-VII.1 |
|
gd-157 |
64157 |
ENDF/B-VII.1 |
|
gd-158 |
64158 |
ENDF/B-VII.1 |
|
gd-160 |
64160 |
ENDF/B-VII.1 |
|
ge-70 |
32070 |
BLO approximation data |
|
ge-72 |
32072 |
BLO approximation data |
|
ge-73 |
32073 |
BLO approximation data |
|
ge-74 |
32074 |
BLO approximation data |
|
ge-76 |
32076 |
BLO approximation data |
|
graphite |
3006000 |
ENDF/B-VII.1 |
Duplicate of c |
h |
1001 |
ENDF/B-VII.2 prelim |
Duplicate of h1 |
h-3 |
1003 |
BLO approximation data |
|
h-benzene |
6001001 |
ENDF/B-VII.2 prelim |
Duplicate of h-1 |
h-benzene |
5006000 |
ENDF/B-VII.1 |
Duplicate of c |
h-cryo_ortho |
4001001 |
ENDF/B-VII.2 prelim |
Duplicate of h-1 |
h-cryo_para |
5001001 |
ENDF/B-VII.2 prelim |
Duplicate of h-1 |
h-liquid_ch4 |
1001001 |
ENDF/B-VII.2 prelim |
Duplicate of h-1 |
h-poly |
9001001 |
ENDF/B-VII.2 prelim |
Duplicate of h-1 |
h-solid_ch4 |
2001001 |
ENDF/B-VII.2 prelim |
Duplicate of h-1 |
h-zrh2 |
7001001 |
ENDF/B-VII.2 prelim |
Duplicate of h-1 |
he-3 |
2003 |
BLO approximation data |
|
he-4 |
2004 |
ENDF/B-VII.1 |
|
hf |
72000 |
BLO approximation data |
|
hf-174 |
72174 |
BLO approximation data |
|
hf-176 |
72176 |
BLO approximation data |
|
hf-177 |
72177 |
BLO approximation data |
|
hf-178 |
72178 |
BLO approximation data |
|
hf-179 |
72179 |
BLO approximation data |
|
hf-180 |
72180 |
BLO approximation data |
|
hfreegas |
8001001 |
ENDF/B-VII.2 prelim |
|
hg-196 |
80196 |
BLO approximation data |
|
hg-198 |
80198 |
BLO approximation data |
|
hg-199 |
80199 |
BLO approximation data |
|
hg-200 |
80200 |
BLO approximation data |
|
hg-201 |
80201 |
BLO approximation data |
|
hg-202 |
80202 |
BLO approximation data |
|
hg-204 |
80204 |
BLO approximation data |
|
ho-165 |
67165 |
BLO approximation data |
|
ho-166m |
1067166 |
BLO approximation data |
|
i-127 |
53127 |
ENDF/B-VII.1 |
|
i-129 |
53129 |
ENDF/B-VII.1 |
|
i-130 |
53130 |
BLO approximation data |
|
i-131 |
53131 |
BLO approximation data |
|
i-135 |
53135 |
BLO approximation data |
|
in |
49000 |
ENDF/B-VI |
|
in-113 |
49113 |
BLO approximation data |
|
in-115 |
49115 |
BLO approximation data |
|
ir-191 |
77191 |
ENDF/B-VII.1 |
|
ir-193 |
77193 |
ENDF/B-VII.1 |
|
k |
19000 |
BLO approximation data |
|
k-39 |
19039 |
ENDF/B-VII.1 |
|
k-40 |
19040 |
BLO approximation data |
|
k-41 |
19041 |
ENDF/B-VII.1 |
|
kr-78 |
36078 |
BLO approximation data |
|
kr-80 |
36080 |
BLO approximation data |
|
kr-82 |
36082 |
BLO approximation data |
|
kr-83 |
36083 |
BLO approximation data |
|
kr-84 |
36084 |
BLO approximation data |
|
kr-85 |
36085 |
BLO approximation data |
|
kr-86 |
36086 |
BLO approximation data |
|
la-138 |
57138 |
BLO approximation data |
|
la-139 |
57139 |
ENDF/B-VII.1 |
|
la-140 |
57140 |
BLO approximation data |
|
li-6 |
3006 |
ENDF/B-VII.1 |
|
li-7 |
3007 |
ENDF/B-VII.1 |
|
lu-175 |
71175 |
BLO approximation data |
|
lu-176 |
71176 |
BLO approximation data |
|
mg |
12000 |
BLO approximation data |
|
mg-24 |
12024 |
ENDF/B-VII.1 |
|
mg-25 |
12025 |
ENDF/B-VII.1 |
|
mg-26 |
12026 |
ENDF/B-VII.1 |
|
mn-55 |
25055 |
ENDF/B-VII.1 |
|
mo |
42000 |
BLO approximation data |
|
mo-100 |
42100 |
ENDF/B-VII.1 |
|
mo-92 |
42092 |
ENDF/B-VII.1 |
|
mo-94 |
42094 |
ENDF/B-VII.1 |
|
mo-95 |
42095 |
ENDF/B-VII.1 |
|
mo-96 |
42096 |
ENDF/B-VII.1 |
|
mo-97 |
42097 |
ENDF/B-VII.1 |
|
mo-98 |
42098 |
ENDF/B-VII.1 |
|
mo-99 |
42099 |
BLO approximation data |
|
n-14 |
7014 |
BLO approximation data |
|
n-15 |
7015 |
ENDF/B-VII.1 |
|
na-23 |
11023 |
ENDF/B-VII.1 |
|
nb-93 |
41093 |
ENDF/B-VI |
|
nb-94 |
41094 |
BLO approximation data |
|
nb-95 |
41095 |
ENDF/B-VII.1 |
|
nd-142 |
60142 |
BLO approximation data |
|
nd-143 |
60143 |
ENDF/B-VII.1 |
|
nd-144 |
60144 |
BLO approximation data |
|
nd-145 |
60145 |
ENDF/B-VII.1 |
|
nd-146 |
60146 |
ENDF/B-VII.1 |
|
nd-147 |
60147 |
BLO approximation data |
|
nd-148 |
60148 |
ENDF/B-VII.1 |
|
nd-148 |
60148 |
BLO approximation data |
|
nd-150 |
60150 |
BLO approximation data |
|
ni-58 |
28058 |
ENDF/B-VII.1 |
|
ni-59 |
28059 |
BLO approximation data |
|
ni-60 |
28060 |
ENDF/B-VII.1 |
|
ni-61 |
28061 |
ENDF/B-VI |
|
ni-62 |
28062 |
ENDF/B-VI |
|
ni-64 |
28064 |
ENDF/B-VI |
|
np-234 |
93234 |
ENDF/B-VII.1 |
|
np-235 |
93235 |
ENDF/B-VII.1 |
|
np-236 |
93236 |
ENDF/B-VII.1 |
|
np-237 |
93237 |
ENDF/B-VII.1 \(\chi\) covariance JENDL-4.0 |
|
np-238 |
93238 |
ENDF/B-VII.1 |
|
np-239 |
93239 |
ENDF/B-VII.1 |
|
o-16 |
8016 |
ENDF/B-VII.1 |
|
o-17 |
8017 |
BLO approximation data |
|
o-beo |
5008016 |
ENDF/B-VII.1 |
Duplicate of o-16 |
o-uo2 |
1008016 |
ENDF/B-VII.1 |
Duplicate of o-16 |
p-31 |
15031 |
BLO approximation data |
|
pa-229 |
91229 |
ENDF/B-VII.1 |
|
pa-230 |
91230 |
ENDF/B-VII.1 |
|
pa-231 |
91231 |
BLO approximation data \(\chi\) covariance JENDL-4.0 |
|
pa-232 |
91232 |
ENDF/B-VII.1 |
|
pa-233 |
91233 |
BLO approximation data \(\chi\) covariance JENDL-4.0 |
|
pb-204 |
82204 |
ENDF/B-VII.1 |
|
pb-206 |
82206 |
ENDF/B-VII.1 |
|
pb-207 |
82207 |
ENDF/B-VII.1 |
|
pb-208 |
82208 |
ENDF/B-VII.1 |
|
pd-102 |
46102 |
BLO approximation data |
|
pd-104 |
46104 |
BLO approximation data |
|
pd-105 |
46105 |
ENDF/B-VII.1 |
|
pd-106 |
46106 |
ENDF/B-VII.1 |
|
pd-107 |
46107 |
ENDF/B-VII.1 |
|
pd-108 |
46108 |
ENDF/B-VII.1 |
|
pd-110 |
46110 |
BLO approximation data |
|
pm-147 |
61147 |
ENDF/B-VII.1 |
Thermal and resonance range uncertainty values from Mughabghab |
pm-148 |
61148 |
BLO approximation data |
|
pm-148m |
1061148 |
BLO approximation data |
|
pm-149 |
61149 |
BLO approximation data |
|
pm-151 |
61151 |
BLO approximation data |
|
pr-141 |
59141 |
ENDF/B-VII.1 |
|
pr-142 |
59142 |
BLO approximation data |
|
pr-143 |
59143 |
BLO approximation data |
|
pu-236 |
94236 |
ENDF/B-VII.1 |
|
pu-237 |
94237 |
ENDF/B-VII.1 |
|
pu-238 |
94238 |
ENDF/B-VII.1 |
|
pu-239 |
94239 |
ENDF/B-VII.2 prelim |
|
pu-240 |
94240 |
ENDF/B-VII.1 |
|
pu-241 |
94241 |
ENDF/B-VII.1 \(\chi\) covariance JENDL-4.0 |
|
pu-242 |
94242 |
ENDF/B-VII.1 |
|
pu-243 |
94243 |
BLO approximation data |
|
pu-244 |
94244 |
ENDF/B-VII.1 |
|
pu-246 |
94246 |
ENDF/B-VII.1 |
|
rb-85 |
37085 |
BLO approximation data |
|
rb-86 |
37086 |
BLO approximation data |
|
rb-87 |
37087 |
BLO approximation data |
|
re-185 |
75185 |
ENDF/B-VI |
|
re-187 |
75187 |
ENDF/B-VI |
|
rh-103 |
45103 |
ENDF/B-VII.1 |
Uses ENDF/B-VII.1 data uncertainty in the thermal range for MT=102 |
rh-105 |
45105 |
BLO approximation data |
|
ru-100 |
44100 |
BLO approximation data |
|
ru-101 |
44101 |
ENDF/B-VII.1 |
|
ru-102 |
44102 |
ENDF/B-VII.1 |
|
ru-103 |
44103 |
ENDF/B-VII.1 |
|
ru-104 |
44104 |
ENDF/B-VII.1 |
|
ru-105 |
44105 |
BLO approximation data |
|
ru-106 |
44106 |
ENDF/B-VII.1 |
|
ru-96 |
44096 |
BLO approximation data |
|
ru-98 |
44098 |
BLO approximation data |
|
ru-99 |
44099 |
BLO approximation data |
|
s |
16000 |
BLO approximation data |
|
s-32 |
16032 |
BLO approximation data |
|
s-33 |
16033 |
BLO approximation data |
|
s-34 |
16034 |
BLO approximation data |
|
s-36 |
16036 |
BLO approximation data |
|
sb-121 |
51121 |
BLO approximation data |
|
sb-123 |
51123 |
BLO approximation data |
|
sb-124 |
51124 |
BLO approximation data |
|
sb-125 |
51125 |
BLO approximation data |
|
sb-126 |
51126 |
BLO approximation data |
|
sc-45 |
21045 |
ENDF/B-VI |
|
se-74 |
34074 |
BLO approximation data |
|
se-76 |
34076 |
BLO approximation data |
|
se-77 |
34077 |
BLO approximation data |
|
se-78 |
34078 |
BLO approximation data |
|
se-79 |
34079 |
BLO approximation data |
|
se-80 |
34080 |
BLO approximation data |
|
se-82 |
34082 |
BLO approximation data |
|
si |
14000 |
ENDF/B-VI |
|
si-28 |
14028 |
ENDF/B-VII.1 |
|
si-29 |
14029 |
ENDF/B-VII.1 |
|
si-30 |
14030 |
ENDF/B-VII.1 |
|
si-28 in SiO2 |
14728 |
ENDF/B-VII.1 |
Duplicate of si-28 |
si-29 in SiO2 |
14729 |
ENDF/B-0VII.1 |
Duplicate of si-29 |
si-30 in SiO2 |
14730 |
ENDF/B-VII.1 |
Duplicate of si-30 |
sm-144 |
62144 |
BLO approximation data |
|
sm-147 |
62147 |
BLO approximation data |
|
sm-148 |
62148 |
BLO approximation data |
|
sm-149 |
62149 |
ENDF/B-VII.1 |
Uses ENDF/B-VII.1 data uncertainty in the thermal range for MT=102 |
sm-149 |
62149 |
BLO approximation data |
|
sm-150 |
62150 |
BLO approximation data |
|
sm-151 |
62151 |
ENDF/B-VII.1 |
Uses ENDF/B-VII.1 data uncertainty in the thermal range for MT=102 |
sm-152 |
62152 |
ENDF/B-VII.1 |
|
sm-153 |
62153 |
BLO approximation data |
|
sm-154 |
62154 |
BLO approximation data |
|
sn-112 |
50112 |
BLO approximation data |
|
sn-113 |
50113 |
BLO approximation data |
|
sn-114 |
50114 |
BLO approximation data |
|
sn-115 |
50115 |
BLO approximation data |
|
sn-116 |
50116 |
BLO approximation data |
|
sn-117 |
50117 |
BLO approximation data |
|
sn-118 |
50118 |
BLO approximation data |
|
sn-119 |
50119 |
BLO approximation data |
|
sn-120 |
50120 |
BLO approximation data |
|
sn-122 |
50122 |
BLO approximation data |
|
sn-123 |
50123 |
BLO approximation data |
|
sn-124 |
50124 |
BLO approximation data |
|
sn-125 |
50125 |
BLO approximation data |
|
sn-126 |
50126 |
BLO approximation data |
|
sr-84 |
38084 |
BLO approximation data |
|
sr-86 |
38086 |
BLO approximation data |
|
sr-87 |
38087 |
BLO approximation data |
|
sr-88 |
38088 |
BLO approximation data |
|
sr-89 |
38089 |
BLO approximation data |
|
sr-90 |
38090 |
BLO approximation data |
|
ta-181 |
73181 |
BLO approximation data |
|
ta-182 |
73182 |
BLO approximation data |
|
tb-159 |
65159 |
BLO approximation data |
|
tb-160 |
65160 |
BLO approximation data |
|
tc-99 |
43099 |
ENDF/B-VII.1 |
|
te-120 |
52120 |
BLO approximation data |
|
te-122 |
52122 |
BLO approximation data |
|
te-123 |
52123 |
BLO approximation data |
|
te-124 |
52124 |
BLO approximation data |
|
te-125 |
52125 |
BLO approximation data |
|
te-126 |
52126 |
BLO approximation data |
|
te-127m |
1052127 |
BLO approximation data |
|
te-128 |
52128 |
BLO approximation data |
|
te-129m |
1052129 |
BLO approximation data |
|
te-130 |
52130 |
BLO approximation data |
|
te-132 |
52132 |
BLO approximation data |
|
th-227 |
90227 |
ENDF/B-VII.1 |
|
th-228 |
90228 |
ENDF/B-VII.1 |
|
th-229 |
90229 |
ENDF/B-VII.1 |
|
th-230 |
90230 |
ENDF/B-VII.1 |
|
th-231 |
90231 |
ENDF/B-VII.1 |
|
th-232 |
90232 |
ENDF/B-VII.1 \(\chi\) covariance JENDL-4.0 |
|
th-233 |
90233 |
ENDF/B-VII.1 |
|
th-234 |
90234 |
ENDF/B-VII.1 |
|
ti |
22000 |
BLO approximation data |
|
ti-46 |
22046 |
ENDF/B-VII.1 |
|
ti-47 |
22047 |
ENDF/B-VII.1 |
|
ti-48 |
22048 |
ENDF/B-VII.1 |
|
ti-49 |
22049 |
ENDF/B-VII.1 |
|
ti-50 |
22050 |
ENDF/B-VII.1 |
|
tl-203 |
81203 |
ENDF/B-VII.1 |
|
tl-205 |
81205 |
ENDF/B-VII.1 |
|
tm-169 |
69169 |
ENDF/B-VII.1 |
|
tm-170 |
69170 |
ENDF/B-VII.1 |
|
u-230 |
92230 |
ENDF/B-VII.1 |
|
u-231 |
92231 |
ENDF/B-VII.1 |
|
u-232 |
92232 |
ENDF/B-VII.1 |
|
u-233 |
92233 |
ENDF/B-VII.1 \(\chi\) covariance JENDL-4.0 |
|
u-234 |
92234 |
ENDF/B-VII.1 |
|
u-235 |
92235 |
ENDF/B-VII.2 prelim |
|
u-236 |
92236 |
ENDF/B-VII.1 |
|
u-237 |
92237 |
BLO approximation data |
|
u-238 |
92238 |
ENDF/B-VII.1 |
|
u-239 |
92239 |
BLO approximation data |
|
u-240 |
92240 |
BLO approximation data |
|
u-241 |
92241 |
BLO approximation data |
|
u-uo2 |
1092235 |
ENDF/B-VII.1 |
Duplicate of u-235 |
v |
23000 |
BLO approximation data |
|
v-50 |
23050 |
BLO approximation data |
Duplicate of v |
v-51 |
23051 |
BLO approximation data |
Duplicate of v |
w |
74000 |
BLO approximation data |
|
w-180 |
74180 |
ENDF/B-VII.1 |
|
w-182 |
74182 |
ENDF/B-VII.1 |
|
w-183 |
74183 |
ENDF/B-VII.1 |
|
w-184 |
74184 |
ENDF/B-VII.1 |
|
w-186 |
74186 |
ENDF/B-VII.1 |
|
xe-123 |
54123 |
BLO approximation data |
|
xe-124 |
54124 |
BLO approximation data |
|
xe-126 |
54126 |
BLO approximation data |
|
xe-128 |
54128 |
BLO approximation data |
|
xe-129 |
54129 |
BLO approximation data |
|
xe-130 |
54130 |
BLO approximation data |
|
xe-131 |
54131 |
ENDF/B-VII.1 |
|
xe-132 |
54132 |
ENDF/B-VII.1 |
|
xe-133 |
54133 |
BLO approximation data |
|
xe-134 |
54134 |
ENDF/B-VII.1 |
|
xe-135 |
54135 |
BLO approximation data |
|
xe-136 |
54136 |
BLO approximation data |
|
y-89 |
39089 |
ENDF/B-VII.1 |
|
y-90 |
39090 |
BLO approximation data |
|
y-91 |
39091 |
BLO approximation data |
|
zr |
40000 |
BLO approximation data |
|
zr-90 |
40090 |
ENDF/B-VII.1 |
|
zr-91 |
40091 |
ENDF/B-VII.1 |
|
zr-92 |
40092 |
ENDF/B-VII.1 |
|
zr-93 |
40093 |
ENDF/B-VII.1 |
|
zr-94 |
40094 |
ENDF/B-VII.1 |
|
zr-95 |
40095 |
ENDF/B-VII.1 |
|
zr-96 |
40096 |
ENDF/B-VII.1 |
|
zr-90-zr5h8 |
1040090 |
ENDF/B-VII.1 |
Duplicate of zr-90 |
zr-91-zr5h8 |
1040091 |
ENDF/B-VII.1 |
Duplicate of zr-91 |
zr-92-zr5h8 |
1040092 |
ENDF/B-VII.1 |
Duplicate of zr-92 |
zr-93-zr5h8 |
1040093 |
ENDF/B-VII.1 |
Duplicate of zr-93 |
zr-94-zr5h8 |
1040094 |
ENDF/B-VII.1 |
Duplicate of zr-94 |
zr-95-zr5h8 |
1040095 |
ENDF/B-VII.1 |
Duplicate of zr-95 |
zr-96-zr5h8 |
1040096 |
ENDF/B-VII.1 |
Duplicate of zr-96 |
Nuclide 1 |
Reaction 1 |
Nuclide 2 |
Reaction 2 |
|---|---|---|---|
239Pu |
Fission |
6Li |
Triton production |
239Pu |
Fission |
197Au |
Capture |
239Pu |
Fission |
235U |
Fission |
239Pu |
Fission |
238U |
Fission |
235U |
Fission |
197Au |
Capture |
235U |
Fission |
6Li |
Triton production |
238U |
Capture |
197Au |
Capture |
238U |
Capture |
235U |
Fission |
10.3.5. SCALE 6.1 44-group covariance library
The older 44-group covariance library distributed with SCALE 6.0 and SCALE 6.1 is included with this distribution for backwards compatibility. The 44-group covariance library provides uncertainty data for a total of 401 materials, including some duplication for materials with multiple thermal scattering kernels. However, the 44-group library was created prior to the official release of ENDF/B-VII.1. Therefore, it is recommended that the 56- or 252-group covariances be used rather than the 44-group. As discussed in Sect. 10.3.1, it is assumed that covariances taken from one data evaluation such as ENDF/B-VI or JENDL-3.3 can also be applied to other evaluations of the same data, such as ENDF/B-VII. If this is done judiciously for cases in which the nuclear data evaluations are similar, then the covariances taken from one source should be a reasonable representation of uncertainties for the other evaluations. Among the materials in the SCALE 44-group library with covariances taken from high-fidelity nuclear data evaluations are the following:
a) ENDF/B-VII evaluations (includes both VII.0 and pre-release covariances proposed for VII.1, but no official ENDF/B-VII.1):
Au, 209Bi, 59Co, 152,154,155,156Gd, 191,193I, 7Li, 23Na, 93Nb, 58Ni, 99Tc,232Th, 48Ti, 239Pu, 233,235,238U,V
ENDF/B-VI evaluations:
Al, 241Am, 10B, 12C, 50,52,53,54Cr, 63,65Cu, 54,56,57Fe, In, 55Mn, 60,61,62,64Ni, 206,207,208Pb, 242Pu, 28,29Si
JENDL-3.3 evaluations:
11B, 1H, 16O, 240,241Pu
Two modifications were also made to the ENDF/B-VII evaluated nubar covariances. These nubar uncertainties are believed to be more realistic. The ENDF/B-VII.0 235U thermal nubar uncertainty of 0.71% was revised to the JENDL-3.3 value of 0.31%. In addition, the thermal nubar certainty in the pre-released ENDF/B-VII.1 233U evaluation was modified to the value in a recent ORNL data evaluation [COVLIBLWRD08]. This ORNL 233U cross section evaluation also provided the thermal and resonance cross sections for the prereleased ENDF/B-VII.1 data. The ENDF/B-VII.1 pre-release nubar data for 239Pu was incomplete when the 44-group covariance library was generated, so 239Pu nubar data are included from ENDF/B-V, the most current data available at that time. This value is much higher than the current estimated uncertainty in 239Pu nubar. The basic ENDF/B uncertainty files that were changed are described in Table 10.3.3.
Several modifications were also made to the uncertainties obtained from the BLO data. The BLO thermal uncertainties for 1H capture and elastic and for 16O elastic were modified to the JENDL-3.3 values of 0.5% and 0.1%, respectively. Similarly, the uncertainty in the 10B (n,alpha) thermal cross section was modified to the ENDF/B-VI value of about 0.2%, since this is more consistent with the Mughabghab integral uncertainty. The uncertainty in the 149Sm resonance capture integral is not provided in the 2006 edition of Mughabghab’s text; therefore it was set to the value of 5.7% which was obtained from an earlier tabulation by Mughabghab [COVLIBMug03].
ENDF/B-VII.1 pre-release 239Pu |
Data were incomplete at time of library generation, so ENDF/B-V data were used for nubar. |
|---|---|
ENDF/B-VII 235U |
Thermal nubar modified to JENDL-3.3 value |
ENDF/B-VII 233U |
Thermal nubar modified to value from ORNL internal evaluation |
ENDF/B-VI 241Am |
Thermal uncertainties were added to total cross section (set equal to capture uncertainties) |
ENDF/B-VI 28Si, 29Si, 30Si, 206Pb, 57Fe |
In elastic scatter uncertainty, corrected cross reference to MT=102 from original value of MT=1.02 |
ENDF/B-VI 208Pb, 207Pb |
Removed MT=3 due to inconsistency with other MT values, resulting in very large uncertainty predictions |
At the time of the preparation of the 44-group covariance library, ENDF/B did not provide fission spectra uncertainty estimates. The methodology used to construct these data for the 44-group covariance library is described in Broadhead and Wagschal [COVLIBBW04]. In this approach, the fission spectrum is represented as either a Watt or Maxwellian distribution. These energy distributions are widely used to represent fission spectra and have been commonly employed in many ENDF/B evaluations. For example, Watt and Maxwellian expressions were used almost exclusively to describe fission spectra in ENDF/B-V and also for many ENDF/B-VI evaluations. More recent evaluations for some important fissionable nuclides have replaced the simple Watt and Maxwellian analytical expressions by distributions such as the Madland-Nix spectrum obtained from more phenomenological nuclear fission models. However, it is assumed here that uncertainties based on an appropriate Watt or Maxwellian representation of the fission spectrum can be transferred to the actual fission spectra contained in the different multigroup cross section libraries.
The methodology in Broadhead and Wagschal [COVLIBBW04] determines energy-dependent covariances from uncertainties and correlations in the a and b parameters for the Watt spectrum or the T parameter for a Maxwellian spectrum, appearing the analytical expressions given below:
Watt Spectrum: \(\chi(\mathrm{E})=\frac{\mathrm{e}^{-\mathrm{E} / \mathrm{a}}}{\mathrm{I}} \sinh (\sqrt{\mathrm{bE}})\)
Maxwellian Spectrum: \(\chi(\mathrm{E})=\frac{\sqrt{\mathrm{E}} \mathrm{e}^{-\mathrm{E} / \mathrm{T}}}{\mathrm{I}}\)
In these expressions, the parameter “I” is the normalization factor required to normalize the integrated spectrum to unity. The value of “I” is fixed by the values of the other parameters. Due to the normalization constraint, the fission spectrum covariance includes anti-correlations. The assumed fission spectra parameters and uncertainties are given in Maerker, Marable, and Wagschal 1980 [COVLIBMMW80] and in Howerton and Doyas 1971 [COVLIBHD71].
Table 10.3.4 shows that fission spectra covariances are not provided for all fissionable materials in the SCALE multigroup cross sections. Table 10.3.5 lists the fissionable nuclides without fission spectra covariances on the 44-group covariance library.
Watt spectrum |
a or T |
b |
Source of parameters |
\(\sigma_a\) or \(\sigma_T\) (%) |
\(\sigma_b\) (%) |
Source of uncertainty |
|---|---|---|---|---|---|---|
235U |
0.988 |
2.249 |
ENDF/B-V |
1.2 |
5.9 |
TANS16 |
238U |
0.881 |
3.401 |
ENDF/B-V |
1.2 |
5.9 |
TANS16 |
233U |
0.977 |
2.546 |
ENDF/B-V |
1.2 |
5.9 |
TANS16 |
239Pu |
0.966 |
2.842 |
ENDF/B-V |
1.2 |
5.9 |
TANS16 |
232Th |
1.0888 |
1.6871 |
ENDF/B-V |
1.2 |
5.9 |
TANS16 |
252Cf |
1.025 |
2.926 |
ENDF/B-V |
1.2 |
5.9 |
TANS16 |
Maxwellian Spectrum |
||||||
238Pu |
1.330 |
- |
ENDF/B-V |
3.01 |
- |
NSE17 |
240Pu |
1.346 |
- |
ENDF/B-V |
2.97 |
- |
NSE17 |
241Pu |
1.3597 |
- |
ENDF/B-V |
2.50 |
- |
NSE17 |
242Pu |
1.337 |
- |
ENDF/B-V |
5.24 |
- |
NSE17 |
241Am |
244Cm |
238Pu |
|---|---|---|
242Am |
245Cm |
243Pu |
243Am |
246Cm |
244Pu |
249Bk |
247Cm |
230Th |
249Cf |
248Cm |
232U |
250Cf |
237Np |
234U |
251Cf |
238Np |
236U |
253Cf |
239Np |
237U |
242Cm |
231Pa |
|
243Cm |
233Pa |
Table 10.3.6 describes the contents of the library using the following nomenclature:
ENDF/B-VII.0: evaluated covariance data released with ENDF/B-VII.0
ENDF/B-VII-p: recently evaluated data proposed for future release of ENDF/B-VII.1
ENDF/B-VI: evaluated covariance data released with ENDF/B-VI
JENDL-3.3: evaluated covariance data in JENDL-3.3
BLO approximate data: lo-fi covariances from BLO project
BLO LANL evaluation: LANL R-matrix evaluation from BLO project
SG-26: approximate covariances from WPEC Subgroup-26
SCALE name |
Data source |
Comments |
ac-225 |
BLO approximate data |
|
ac-226 |
BLO approximate data |
|
ac-227 |
BLO approximate data |
|
ag-107 |
BLO approximate data |
|
ag-109 |
BLO approximate data |
|
ag-110m |
BLO approximate data |
|
ag-111 |
BLO approximate data |
|
al-27 |
ENDF/B-VI |
|
am-241 |
ENDF/B-VI |
MT=452 added corrections for total and elastic) |
am-242 |
SG-26 |
Thermal uncertainty replaced by Mughabghab value |
am-242m |
SG-26 |
Thermal uncertainty replaced by Mughabghab value |
am-243 |
BLO approximate data |
|
am-244 |
BLO approximate data |
|
am-244m |
BLO approximate data |
|
ar-36 |
BLO approximate data |
|
ar-38 |
BLO approximate data |
|
ar-40 |
BLO approximate data |
|
as-74 |
BLO approximate data |
|
as-75 |
BLO approximate data |
|
au-197 |
ENDF/B-VII-p |
Pre-released evaluation proposed for ENDF/B-VII.1 |
b-10 |
BLO LANL evaluation +ENDF/B-VI |
LANL high-fidelity covariance, with ENDF/B-VI for thermal |
b-11 |
JENDL 3.3 |
|
ba-130 |
BLO approximate data |
|
ba-132 |
BLO approximate data |
|
ba-133 |
BLO approximate data |
|
ba-135 |
BLO approximate data |
|
ba-136 |
BLO approximate data |
|
ba-137 |
BLO approximate data |
|
ba-138 |
BLO approximate data |
|
ba-140 |
BLO approximate data |
|
be-7 |
BLO approximate data |
|
be-9 |
BLO approximate data |
|
Bebound |
BLO approximate data |
Duplicate of 9Be |
bi-209 |
ENDF/B-VII-p |
Pre-released evaluation proposed for ENDF/B-VII.1 |
bk-249 |
BLO approximate data |
|
bk-250 |
BLO approximate data |
|
br-79 |
BLO approximate data |
|
br-81 |
BLO approximate data |
|
C |
ENDF/B-VI |
|
C-graphite |
ENDF/B-VI |
Duplicate of carbon |
Ca |
BLO approximate data |
|
ca-40 |
BLO approximate data |
|
ca-42 |
BLO approximate data |
|
ca-43 |
BLO approximate data |
|
ca-44 |
BLO approximate data |
|
ca-46 |
BLO approximate data |
|
ca-48 |
BLO approximate data |
|
Cd |
BLO approximate data |
|
cd-106 |
BLO approximate data |
|
cd-108 |
BLO approximate data |
|
cd-110 |
BLO approximate data |
|
cd-111 |
BLO approximate data |
|
cd-112 |
BLO approximate data |
|
cd-113 |
BLO approximate data |
|
cd-114 |
BLO approximate data |
|
cd-115m |
BLO approximate data |
|
cd-116 |
BLO approximate data |
|
cd-136 |
BLO approximate data |
|
cd-138 |
BLO approximate data |
|
cd-139 |
BLO approximate data |
|
cd-140 |
BLO approximate data |
|
cd-141 |
BLO approximate data |
|
cd-142 |
BLO approximate data |
|
ce-143 |
BLO approximate data |
|
ce-144 |
BLO approximate data |
|
cf-249 |
BLO approximate data |
|
cf-250 |
BLO approximate data |
|
cf-251 |
BLO approximate data |
|
cf-252 |
BLO approximate data |
|
cf-253 |
BLO approximate data |
|
cf-254 |
BLO approximate data |
|
Cl |
BLO approximate data |
|
cl-35 |
BLO approximate data |
|
cl-37 |
BLO approximate data |
|
cm-241 |
BLO approximate data |
Thermal uncertainty |
cm-242 |
SG-26 |
Mughabghab value |
cm-243 |
SG-26 |
Thermal uncertainty replaced by Mughabghab value |
cm-244 |
SG-26 |
Thermal uncertainty replaced by Mughabghab value |
cm-245 |
SG-26 |
Thermal uncertainty replaced by Mughabghab value |
cm-246 |
BLO approximate data |
|
cm-247 |
BLO approximate data |
|
cm-248 |
BLO approximate data |
|
cm-249 |
BLO approximate data |
|
cm-250 |
BLO approximate data |
|
co-58 co-58m co-59 |
BLO approximate data BLO approximate data ENDF/B-VII-p |
Pre-released evaluation proposed for ENDF/B-VII.1 |
cr-50 |
ENDF/B-VI |
LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
cr-52 |
ENDF/B-VI |
LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
cr-53 |
ENDF/B-VI |
LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
cr-54 |
ENDF/B-VI |
LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
cs-133 |
BLO approximate data |
|
cs-134 |
BLO approximate data |
|
cs-135 |
BLO approximate data |
|
cs-136 |
BLO approximate data |
|
cs-137 |
BLO approximate data |
|
cu-63 |
ENDF/B-VI |
|
cu-65 |
ENDF/B-VI |
|
dy-156 |
BLO approximate data |
|
dy-158 |
BLO approximate data |
|
dy-160 |
BLO approximate data |
|
dy-161 |
BLO approximate data |
|
dy-162 |
BLO approximate data |
|
dy-163 |
BLO approximate data |
|
dy-164 |
BLO approximate data |
|
er-162 |
BLO approximate data |
|
er-164 |
BLO approximate data |
|
er-166 |
BLO approximate data |
|
er-167 |
BLO approximate data |
|
er-168 |
BLO approximate data |
|
er-170 |
BLO approximate data |
|
es-253 |
BLO approximate data |
|
es-254 |
BLO approximate data |
|
es-255 |
BLO approximate data |
|
eu-151 |
BLO approximate data |
|
eu-152 |
BLO approximate data |
|
eu-153 |
BLO approximate data |
|
eu-154 |
BLO approximate data |
|
eu-155 eu-156 eu-157 |
BLO approximate data BLO approximate data BLO approximate data |
|
f-19 |
BLO approximate data |
|
fe-54 |
ENDF/B-VI |
LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
fe-56 |
ENDF/B-VI |
LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
fe-57 |
ENDF/B-VI |
Error in file corrected LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
fe-58 fm-255 |
ENDF/B-VI BLO approximate data |
LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. New material not in previous SCALE 5.1 covariance libraries. |
Ga ga-69 ga-71 |
BLO approximate data BLO approximate data BLO approximate data |
|
gd-152 gd-153 |
ENDF/B-VII.0 BLO approximate data |
|
gd-154 |
ENDF/B-VII.0 |
|
gd-155 |
ENDF/B-VII.0 |
|
gd-156 |
ENDF/B-VII.0 |
|
gd-157 |
ENDF/B-VII.0 |
|
gd-158 |
ENDF/B-VII.0 |
|
gd-160 |
ENDF/B-VII.0 |
|
ge-70 |
BLO approximate data |
|
ge-72 |
BLO approximate data |
|
ge-73 |
BLO approximate data |
|
ge-74 |
BLO approximate data |
|
ge-76 |
BLO approximate data |
|
h-1 |
BLO LANL evaluation +JENDL 3.3 |
LANL covariance above 5 keV; JENDL values below 5 keV |
h-ZrH |
BLO LANL evaluation +JENDL 3. |
Duplicate of 1H |
h-poly |
BLO LANL evaluation +JENDL 3. |
Duplicate of 1H |
Hfreegas |
BLO LANL evaluation +JENDL 3. |
Duplicate of 1H |
h-2 |
BLO approximate data |
|
Dfreegas |
BLO approximate data |
Duplicate of 2H |
h-3 |
BLO approximate data |
|
he-3 |
BLO approximate data |
|
he-4 |
BLO approximate data |
|
Hf |
BLO approximate data |
|
hf-174 |
BLO approximate data |
|
hf-176 |
BLO approximate data |
|
fh-177 |
BLO approximate data |
|
hf-178 |
BLO approximate data |
|
hf-179 |
BLO approximate data |
|
hf-180 |
BLO approximate data |
|
hg-196 |
BLO approximate data |
|
hg-198 |
BLO approximate data |
|
hg-199 |
BLO approximate data |
|
hg-200 |
BLO approximate data |
|
hg-201 |
BLO approximate data |
|
hg-202 |
BLO approximate data |
|
hg-204 |
BLO approximate data |
|
ho-165 |
BLO approximate data |
|
i-127 |
BLO approximate data |
|
i-129 |
BLO approximate data |
|
i-130 |
BLO approximate data |
|
i-131 |
BLO approximate data |
|
i-135 |
BLO approximate data |
|
In |
ENDF/B-VI |
|
in-113 in-115 |
BLO approximate data BLO approximate data |
|
ir-191 |
ENDF/B-VII.0 |
|
ir-193 |
ENDF/B-VII.0 |
|
K |
BLO approximate data |
|
k-39 |
BLO approximate data |
|
k-40 |
BLO approximate data |
|
k-41 |
BLO approximate data |
|
kr-78 |
BLO approximate data |
|
kr-80 |
BLO approximate data |
|
kr-82 |
BLO approximate data |
|
kr-83 |
BLO approximate data |
|
kr-84 |
BLO approximate data |
|
kr-85 |
BLO approximate data |
|
kr-86 |
BLO approximate data |
|
la-138 la-139 |
BLO approximate data BLO approximate data |
|
la-140 |
BLO approximate data |
|
li-6 |
BLO-LANL evaluation |
|
li-7 |
ENDF/B-VII.0 |
|
lu-175 |
BLO approximate data |
|
lu-176 |
BLO approximate data |
|
Mg |
BLO approximate data |
|
mg-24 |
BLO approximate data |
|
mg-25 |
BLO approximate data |
|
mg-26 |
BLO approximate data |
|
mn-55 |
ENDF/B-VI |
LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
Mo |
BLO approximate data |
|
mo-92 |
BLO approximate data |
|
mo-94 |
BLO approximate data |
|
mo-95 |
BLO approximate data |
|
mo-96 |
BLO approximate data |
|
mo-97 |
BLO approximate data |
|
mo-98 mo-99 mo-100 |
BLO approximate data BLO approximate data BLO approximate data |
|
n-14 |
BLO approximate data |
|
n-15 |
BLO approximate data |
|
na-23 |
ENDF/B-VII-p |
Pre-released evaluation proposed for ENDF/B-VII.1 |
nb-93 |
ENDF/B-VII-p |
Pre-released evaluation proposed for ENDF/B-VII.1 |
nb-94 |
BLO approximate data |
|
nb-95 |
BLO approximate data |
|
nd-142 |
BLO approximate data |
|
nd-143 |
BLO approximate data |
|
nd-144 |
BLO approximate data |
|
nd-145 |
BLO approximate data |
|
nd-146 |
BLO approximate data |
|
nd-147 |
BLO approximate data |
|
nd-148 |
BLO approximate data |
|
nd-150 |
BLO approximate data |
|
ni-58 ni-59 |
ENDF/B-VII-p BLO approximate data |
Pre-released evaluation proposed for ENDF/B-VII.1 |
ni-60 |
ENDF/B-VI |
LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
ni-61 |
ENDF/B-VI |
LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
ni-62 |
ENDF/B-VI |
LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
ni-64 |
ENDF/B-VI |
LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
np-235 np-236 np-237 |
BLO approximate data BLO approximate data SG-26 |
Thermal uncertainty replaced by Mughabghab value |
np-238 |
BLO approximate data |
|
np-239 |
BLO approximate data |
|
o-16 |
JENDL 3.3+BLO |
BLO covariances from LANL used above 5 keV |
o-17 |
BLO approximate data |
|
p-31 |
BLO approximate data |
|
pa-231 pa-232 |
BLO approximate data BLO approximate data |
|
pa-233 |
BLO approximate data |
|
pb-204 pb-206 |
BLO approximate data ENDF/B-VI |
Error in file corrected |
pb-207 |
ENDF/B-VI |
MT=3 removed, Error in file corrected |
bp-208 |
ENDF/B-VI |
MT=3 removed, Error in file corrected |
pd-102 |
BLO approximate data |
|
pd-104 |
BLO approximate data |
|
pd-105 |
BLO approximate data |
|
pd-106 |
BLO approximate data |
|
pd-107 |
BLO approximate data |
|
pd-108 |
BLO approximate data |
|
pd-110 |
BLO approximate data |
|
pm-147 |
BLO approximate data |
|
pm-148 |
BLO approximate data |
|
pm-148m |
BLO approximate data |
|
pm-149 |
BLO approximate data |
|
pm-151 |
BLO approximate data |
|
pr-141 |
BLO approximate data |
|
pr-142 |
BLO approximate data |
|
pr-143 |
BLO approximate data |
|
pu-236 pu-237 pu-238 |
BLO approximate data BLO approximate data SG-26 |
Thermal uncertainty replaced by Mughabghab value |
pu-239 |
ENDF/B-VII-p |
Pre-released evaluation proposed for ENDF/B-VII.1; nubar data from ENDF/B-V Cross nuclide-to-nuclide matrices present; covariances due to fission cross sections / nubar for each nuclide Table 10.3.2 |
pu-240 |
JENDL 3.3 |
Cross nuclide-to-nuclide matrices present; covariances due to fission cross sections / nubar for each nuclide (Table 10.3.2 |
pu-241 |
JENDL 3.3 |
Cross nuclide-to-nuclide matrices present; covariances due to fission cross sections / nubar for each nuclide (Table 10.3.2) |
pu-242 |
ENDF/B-VI |
|
pu-243 |
BLO approximate data |
|
pu-244 |
BLO approximate data |
|
pu-246 |
BLO approximate data |
|
rb-85 |
BLO approximate data |
|
rb-86 |
BLO approximate data |
|
rb-87 |
BLO approximate data |
|
re-185 |
ENDF/B-VI |
MT=2 added from Mughabghab. LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
re-187 |
ENDF/B-VI |
MT=2 added from Mughabghab. LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
rh-103 |
BLO approximate data |
|
rh-105 |
BLO approximate data |
|
ru-96 |
BLO approximate data |
|
ru-98 |
BLO approximate data |
|
ru-103 |
BLO approximate data |
|
ru-99 |
BLO approximate data |
|
ru-100 |
BLO approximate data |
|
ru-101 |
BLO approximate data |
|
ru-102 |
BLO approximate data |
|
ru-104 |
BLO approximate data |
|
ru-105 |
BLO approximate data |
|
ru-106 |
BLO approximate data |
|
S |
BLO approximate data |
|
s-32 |
BLO approximate data |
|
s-33 |
BLO approximate data |
|
s-34 |
BLO approximate data |
|
s-36 |
BLO approximate data |
|
sb-123 |
BLO approximate data |
|
sb-124 |
BLO approximate data |
|
sb-125 |
BLO approximate data |
|
sb-126 |
BLO approximate data |
|
sc-45 |
ENDF/B-VI |
|
se-74 |
BLO approximate data |
|
se-76 |
BLO approximate data |
|
se-77 |
BLO approximate data |
|
se-78 se-79 |
BLO approximate data BLO approximate data |
|
se-80 |
BLO approximate data |
|
se-82 |
BLO approximate data |
|
Si |
ENDF/B-VI |
|
si-28 |
ENDF/B-VI |
Error in file corrected LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
si-29 |
ENDF/B-VI |
Error in file corrected LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
si-30 |
ENDF/B-VI |
Error in file corrected LB=8 representation caused problematic representation of cross section uncertainty due to use of fine energy group structure. Tests were performed to determine how to handle this problem. LB=8 data were removed in the final results. |
sm-144 |
BLO approximate data |
|
sm-147 |
BLO approximate data |
|
sm-148 |
BLO approximate data |
|
sm-149 |
BLO approximate data |
Resonance range uncertainty from Kawano 2008 |
sm-150 |
BLO approximate data |
|
sm-151 |
BLO approximate data |
|
sm-152 |
BLO approximate data |
|
sm-153 |
BLO approximate data |
|
sm-154 |
BLO approximate data |
|
sn-112 |
BLO approximate data |
|
sn-113 |
BLO approximate data |
|
sn-114 |
BLO approximate data |
|
sn-115 |
BLO approximate data |
|
sn-116 |
BLO approximate data |
|
sn-117 |
BLO approximate data |
|
sn-118 |
BLO approximate data |
|
sn-119 |
BLO approximate data |
|
sn-120 |
BLO approximate data |
|
sn-122 |
BLO approximate data |
|
sn-123 |
BLO approximate data |
|
sn-124 |
BLO approximate data |
|
sn-125 |
BLO approximate data |
|
sr-84 |
BLO approximate data |
|
sr-86 |
BLO approximate data |
|
sr-87 |
BLO approximate data |
|
sr-88 |
BLO approximate data |
|
sr-89 |
BLO approximate data |
|
sr-90 |
BLO approximate data |
|
ta-181 |
BLO approximate data |
|
ta-182 |
BLO approximate data |
|
tb-159 |
BLO approximate data |
|
tb-160 |
BLO approximate data |
|
tc-99 |
ENDF/B-VII.0 |
|
te-120 |
BLO approximate data |
|
te-122 |
BLO approximate data |
|
te-123 |
BLO approximate data |
|
te-124 |
BLO approximate data |
|
te-125 |
BLO approximate data |
|
te-126 |
BLO approximate data |
|
te-127m |
BLO approximate data |
|
te-128 |
BLO approximate data |
|
te-129m |
BLO approximate data |
|
te-130 |
BLO approximate data |
|
th-227 |
BLO approximate data |
|
th-228 |
BLO approximate data |
|
th-229 |
BLO approximate data |
|
th-230 |
BLO approximate data |
|
th-232 th-233 th-234 Ti ti-46 ti-47 ti-48 |
ENDF/B-VII.0 BLO approximate data BLO approximate data BLO approximate data BLO approximate data BLO approximate data ENDF/B-VII-p |
Cross nuclide-to-nuclide matrices present; covariances due to fission cross sections / nubar for each nuclide (Table 10.3.2) Pre-released evaluation proposed for ENDF/B-VII.1 |
ti-49 |
BLO approximate data |
|
ti-50 |
BLO approximate data |
|
u-232 |
BLO approximate data |
|
u-233 |
ENDF/B-VII-p |
Pre-released evaluation proposed for ENDF/B-VII.1; nubar uncertainty from Ref. 14Cross nuclide-to-nuclide matrices present; covariances due to fission cross sections / nubar for each nuclide ( |
u-234 |
SG-26 |
Thermal uncertainty replaced by Mughabghab value |
u-235 |
ENDF/B-VII-p |
Pre-released evaluation proposed for ENDF/B-VII.1; nubar uncertainty from JENDL-3.1 Cross nuclide-to-nuclide matrices present; covariances due to fission cross sections / nubar for each nuclide (Table 10.3.2). |
u-236 |
SG-26 |
Thermal uncertainty replaced by Mughabghab value |
u-237 |
BLO approximate data |
|
u-238 u-239 u-240 u-241 |
ENDF/B-VII-p BLO approximate data BLO approximate data BLO approximate data |
Pre-released evaluation proposed for ENDF/B-VII.1 Cross nuclide-to-nuclide matrices present; covariances due to fission cross sections / nubar for each nuclide (Table 10.3.2). |
V |
ENDF/B-VII-p |
Pre-released evaluation proposed for ENDF/B-VII.1 |
W |
BLO approximate data |
|
w-182 |
BLO approximate data |
|
w-183 |
BLO approximate data |
|
w-184 |
BLO approximate data |
|
w-186 |
BLO approximate data |
|
xe-123 |
BLO approximate data |
|
xe-124 |
BLO approximate data |
|
xe-126 |
BLO approximate data |
|
xe-128 |
BLO approximate data |
|
xe-129 |
BLO approximate data |
|
xe-130 |
BLO approximate data |
|
xe-131 |
BLO approximate data |
|
xe-132 |
BLO approximate data |
|
xe-134 |
BLO approximate data |
|
xe-135 |
BLO approximate data |
|
xe-136 |
BLO approximate data |
|
y-89 |
ENDF/B-VI |
|
y-90 |
BLO approximate data |
|
y-91 |
BLO approximate data |
|
Zr |
BLO approximate data |
|
zr-90 |
BLO approximate data |
|
zr-91 |
BLO approximate data |
|
zr-92 |
BLO approximate data |
|
zr-93 |
BLO approximate data |
|
zr-94 |
BLO approximate data |
|
zr-95 |
BLO approximate data |
|
zr-96 |
BLO approximate data |
Nuclide 1 |
Reaction 1 |
Nuclide 2 |
Reaction 2 |
|---|---|---|---|
240Pu |
Fission |
239Pu |
Fission |
240Pu |
Fission |
233U |
Fission |
240Pu |
Fission |
238U |
Fission |
241Pu |
Fission |
239Pu |
Fission |
241Pu |
Fission |
240Pu |
Fission |
241Pu |
Fission |
233U |
Fission |
241Pu |
Fission |
235U |
Fission |
241Pu |
Fission |
238U |
Fission |
235U |
Fission |
240Pu |
Fission |
References
- COVLIBBW04(1,2)
Bryan L. Broadhead and J. J. Wagschal. The Fission Spectrum Uncertainty. PHYSOR 2004–The Physics of Fuel Cycles and Advanced Nuclear Systems: Global Developments, pages 25–29, 2004.
- COVLIBCHO+11
M.B. Chadwick, M. Herman, P. Obložinský, M.E. Dunn, Y. Danon, A.C. Kahler, D.L. Smith, B. Pritychenko, G. Arbanas, R. Arcilla, R. Brewer, D.A. Brown, R. Capote, A.D. Carlson, Y.S. Cho, H. Derrien, K. Guber, G.M. Hale, S. Hoblit, S. Holloway, T.D. Johnson, T. Kawano, B.C. Kiedrowski, H. Kim, S. Kunieda, N.M. Larson, L. Leal, J.P. Lestone, R.C. Little, E.A. McCutchan, R.E. MacFarlane, M. MacInnes, C.M. Mattoon, R.D. McKnight, S.F. Mughabghab, G.P.A. Nobre, G. Palmiotti, A. Palumbo, M.T. Pigni, V.G. Pronyaev, R.O. Sayer, A.A. Sonzogni, N.C. Summers, P. Talou, I.J. Thompson, A. Trkov, R.L. Vogt, S.C. van der Marck, A. Wallner, M.C. White, D. Wiarda, and P.G. Young. ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data. Nuclear Data Sheets, 112(12):2887–2996, 2011. URL: https://www.sciencedirect.com/science/article/pii/S009037521100113X, doi:https://doi.org/10.1016/j.nds.2011.11.002.
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Gerald Hale. Covariances from light-element r-martix analyses. Technical Report, Los Alamos National Laboratory, Los Alamos, NM (USA), 2008.
- COVLIBHD71
R. J. Howerton and R. J. Doyas. Fission temperatures as a function of the average number of neutrons from fission. Nuclear Science and Engineering, 46(3):414–416, 1971. Publisher: Taylor & Francis.
- COVLIBKTY+08
T. Kawano, P. Talou, P. G. Young, G. Hale, M. B. Chadwick, and R. C. Little. Evaluation of covariances for actinides and light elements at LANL. Nuclear Data Sheets, 109(12):2817–2821, 2008.
- COVLIBLLD+06
N. M. Larson, L. C. Leal, H. Derrien, G. Arbanas, R. O. Sayer, and D. Wiarda. A systematic description of the generation of covariance matrices. In PHYSOR-2006: ANS Topical Meeting on Reactor Physics, 10–14. 2006.
- COVLIBLWRD08
Luiz C. Leal, D. Wiarda, Bradley T. Rearden, and Herve Derrien. 233 U Cross-Section and Covariance Data Update for SCALE 5.1 Libraries. ORNL/TM-2007/115, Oak Ridge National Laboratory, Oak Ridge, Tenn, 2008.
- COVLIBLKH+08(1,2)
R. C. Little, T. Kawano, G. D. Hale, M. T. Pigni, M. Herman, P. Obložinsky, M. L. Williams, M. E. Dunn, G. Arbanas, and D. Wiarda. Low-fidelity Covariance Project. Nuclear Data Sheets, 109(12):2828–2833, 2008. Publisher: Elsevier.
- COVLIBMMW80
R. E. Maerker, J. H. Marable, and J. J. Wagschal. Estimation of the uncertainties in the ENDF/BV Uranium 235 fission spectrum. In Transactions of the American Nuclear Society, volume 35. 1980.
- COVLIBMug03(1,2)
S. F. Mughabghab. Thermal neutron capture cross sections resonance integrals and g-factors. International Atomic Energy Agency, 2003.
- COVLIBMug06(1,2)
Said F. Mughabghab. Atlas of Neutron Resonances: Resonance Parameters and Thermal Cross Sections. Z= 1-100. Elsevier, 2006.
- COVLIBPHO09
M. T. Pigni, M. Herman, and P. Obložinsky. Extensive Set of Cross-Section Covariance Estimates in the Fast Neutron Region. Nuclear science and engineering, 162(1):25–40, 2009. Publisher: Taylor & Francis.
- COVLIBRHOM07
D. Rochman, M. Herman, P. Oblozinsky, and S. F. Mughabghab. Preliminary cross-section covariances for WPEC Subgroup 26. Technical Report BNL-77407-2007-IR, Brookhaven National Laboratory, Upton, NY (USA), 2007.
- COVLIBWD06
D. Wiarda and M. E. Dunn. PUFF-IV: A Code for Processing ENDF Uncertainty Data into Multigroup Covariance Matrices. Technical Report ORNL/TM-2006/147, Oak Ridge National Laboratory, Oak Ridge, TN (USA), 10 2006.
- COVLIBWALD08
Dorothea Wiarda, Goran Arbanas, L. Leal, and Michael E. Dunn. Recent advances with the AMPX covariance processing capabilities in PUFF-IV. Nuclear Data Sheets, 109(12):2791–2795, 2008. Publisher: Elsevier.
- COVLIBWBDR07
Mark L. Williams, Bryan L. Broadhead, Michael E. Dunn, and Bradley T. Rearden. Approximate Techniques for Representing Nuclear Data Uncertainties. In Eighth International Topical Meeting on Nuclear Applications and Utilization of Accelerators (AccApp'07)," Pocatello, ID (July 30-Aug. 2, 2007). 7 2007.
- COVLIBWIMR14
Mark L. Williams, Germina Ilas, William J. Marshall, and Bradley T. Rearden. Applications of nuclear data covariances to criticality safety and spent fuel characterization. Nuclear Data Sheets, 118:341–345, 2014.
- COVLIBWR08(1,2,3,4,5)
Mark L. Williams and Bradley T. Rearden. SCALE-6 Sensitivity/uncertainty methods and covariance data. Nuclear Data Sheets, 109(12):2796–2800, 2008.