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Title: Impact of Active Control on Passive Safety Response Characteristics of Sodium-cooled Fast Reactors: I - Theoretical background

Abstract

Here, the interaction of the active control system with passive safety behavior is investigated for sodium-cooled fast reactors. A claim often made of advanced reactors is that they are passively safe against unprotected upset events. In practice, such upset events are not analyzed in the context of the plant control system, but rather the analyses are performed without considering the normally programmed response of the control system (open-loop approach). This represents an oversimplification of the safety case. The issue of passive safety override arises since the control system commands actuators whose motions have safety consequences. Depending on the upset involving the control system ( operator error, active control system failure, or inadvertent control system override), an actuator does not necessarily go in the same direction as needed for safety. So neglecting to account for control system action during an unprotected upset is nonconservative from a safety standpoint. It is important then, during the design of the plant, to consider the potential for the control system to work against the inherent and safe regulating effects of purposefully engineered temperature feedbacks.

Authors:
ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]
  1. Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Nuclear Energy (NE)
OSTI Identifier:
1389633
Grant/Contract Number:
AC02-06CH11357
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Nuclear Technology
Additional Journal Information:
Journal Volume: 199; Journal ID: ISSN 0029-5450
Publisher:
Taylor & Francis - formerly American Nuclear Society (ANS)
Country of Publication:
United States
Language:
English
Subject:
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; Sodium-cooled fast reactors; active controllers; passive safety

Citation Formats

Passerini, Stefano, Ponciroli, Roberto, and Vilim, Richard B. Impact of Active Control on Passive Safety Response Characteristics of Sodium-cooled Fast Reactors: I - Theoretical background. United States: N. p., 2017. Web. doi:10.1080/00295450.2017.1326782.
Passerini, Stefano, Ponciroli, Roberto, & Vilim, Richard B. Impact of Active Control on Passive Safety Response Characteristics of Sodium-cooled Fast Reactors: I - Theoretical background. United States. doi:10.1080/00295450.2017.1326782.
Passerini, Stefano, Ponciroli, Roberto, and Vilim, Richard B. Wed . "Impact of Active Control on Passive Safety Response Characteristics of Sodium-cooled Fast Reactors: I - Theoretical background". United States. doi:10.1080/00295450.2017.1326782.
@article{osti_1389633,
title = {Impact of Active Control on Passive Safety Response Characteristics of Sodium-cooled Fast Reactors: I - Theoretical background},
author = {Passerini, Stefano and Ponciroli, Roberto and Vilim, Richard B.},
abstractNote = {Here, the interaction of the active control system with passive safety behavior is investigated for sodium-cooled fast reactors. A claim often made of advanced reactors is that they are passively safe against unprotected upset events. In practice, such upset events are not analyzed in the context of the plant control system, but rather the analyses are performed without considering the normally programmed response of the control system (open-loop approach). This represents an oversimplification of the safety case. The issue of passive safety override arises since the control system commands actuators whose motions have safety consequences. Depending on the upset involving the control system ( operator error, active control system failure, or inadvertent control system override), an actuator does not necessarily go in the same direction as needed for safety. So neglecting to account for control system action during an unprotected upset is nonconservative from a safety standpoint. It is important then, during the design of the plant, to consider the potential for the control system to work against the inherent and safe regulating effects of purposefully engineered temperature feedbacks.},
doi = {10.1080/00295450.2017.1326782},
journal = {Nuclear Technology},
number = ,
volume = 199,
place = {United States},
year = {Wed Jun 21 00:00:00 EDT 2017},
month = {Wed Jun 21 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
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