Upgrading Limiting PeakPower Analysis Techniques with Modern Validation and Uncertainty Quantification for the Advanced Test Reactor
Abstract
Here, this work demonstrates the acceptability of the 2D deterministic transport code, HELIOS, to replace the legacy diffusion code, PDQ, for computing the peakpower performance parameters of the Advanced Test Reactor (ATR). The 95% Confidence Rule, commonly used in the commercial reactor sector, is explored to develop the socalled “reliability factors” which provide statistical confidence that the peakpower limits within the hottest location along a fuel plate, referred to as the hotstripe, will not be exceeded. Additionally, an alternative “legacy” methodology was explored that attempts to mimic the exact PDQ analysis process used for defining the peakpower limits. The legacy methodology, involves interpolating power between regions at azimuthal boundaries subtending the regions of interest. In order to apply the 95% Confidence Rule, a statistically significant calculationtomeasurement bias must first be established. Unlike the commercial world where thousands of power observations can be collected every cycle using online flux mapping instrumentation, the ATR power distribution must be measured during “depressurized” zeropower measurements using fission wires in polyethylene wands. In 2012, fission wire activation data was collected during a flux run in the Advanced Test Reactor – Critical facility. Also to improve statistical validity, archival data from ATR zero power flux runsmore »
 Authors:

 Idaho National Lab. (INL), Idaho Falls, ID (United States)
 Publication Date:
 Research Org.:
 Idaho National Lab. (INL), Idaho Falls, ID (United States)
 Sponsoring Org.:
 USDOE Office of Nuclear Energy (NE)
 OSTI Identifier:
 1473711
 Report Number(s):
 INL/JOU1741057Rev000
Journal ID: ISSN 00295450
 Grant/Contract Number:
 AC0705ID14517
 Resource Type:
 Accepted Manuscript
 Journal Name:
 Nuclear Technology
 Additional Journal Information:
 Journal Volume: 201; Journal Issue: 3; Journal ID: ISSN 00295450
 Publisher:
 Taylor & Francis  formerly American Nuclear Society (ANS)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; Advanced Test Reactor; Verification and Validation; Uncertainty Quantification; 95% Confidence Rule; Reliability Factor
Citation Formats
Bays, Samuel E., Davis, Cliff B., and Archibald, Periann A. Upgrading Limiting PeakPower Analysis Techniques with Modern Validation and Uncertainty Quantification for the Advanced Test Reactor. United States: N. p., 2018.
Web. doi:10.1080/00295450.2017.1415091.
Bays, Samuel E., Davis, Cliff B., & Archibald, Periann A. Upgrading Limiting PeakPower Analysis Techniques with Modern Validation and Uncertainty Quantification for the Advanced Test Reactor. United States. doi:10.1080/00295450.2017.1415091.
Bays, Samuel E., Davis, Cliff B., and Archibald, Periann A. Fri .
"Upgrading Limiting PeakPower Analysis Techniques with Modern Validation and Uncertainty Quantification for the Advanced Test Reactor". United States. doi:10.1080/00295450.2017.1415091. https://www.osti.gov/servlets/purl/1473711.
@article{osti_1473711,
title = {Upgrading Limiting PeakPower Analysis Techniques with Modern Validation and Uncertainty Quantification for the Advanced Test Reactor},
author = {Bays, Samuel E. and Davis, Cliff B. and Archibald, Periann A.},
abstractNote = {Here, this work demonstrates the acceptability of the 2D deterministic transport code, HELIOS, to replace the legacy diffusion code, PDQ, for computing the peakpower performance parameters of the Advanced Test Reactor (ATR). The 95% Confidence Rule, commonly used in the commercial reactor sector, is explored to develop the socalled “reliability factors” which provide statistical confidence that the peakpower limits within the hottest location along a fuel plate, referred to as the hotstripe, will not be exceeded. Additionally, an alternative “legacy” methodology was explored that attempts to mimic the exact PDQ analysis process used for defining the peakpower limits. The legacy methodology, involves interpolating power between regions at azimuthal boundaries subtending the regions of interest. In order to apply the 95% Confidence Rule, a statistically significant calculationtomeasurement bias must first be established. Unlike the commercial world where thousands of power observations can be collected every cycle using online flux mapping instrumentation, the ATR power distribution must be measured during “depressurized” zeropower measurements using fission wires in polyethylene wands. In 2012, fission wire activation data was collected during a flux run in the Advanced Test Reactor – Critical facility. Also to improve statistical validity, archival data from ATR zero power flux runs from 1977, 1986, and 1994 were digitized from scanned reports and used to create new benchmark models. Borrowing from leastsquares adjustment methods commonly used for neutron activation spectroscopy, adjusted fission wire powers were calculated for all four datasets. The mean and standard deviation of the bias between a priori calculated and adjusted wirepowers was then taken as the bias and uncertainty used in the 95% Confidence Rule.},
doi = {10.1080/00295450.2017.1415091},
journal = {Nuclear Technology},
number = 3,
volume = 201,
place = {United States},
year = {2018},
month = {2}
}
Figures / Tables:
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Figures / Tables found in this record: