scholarly journals A plant-specific HRA sensitivity analysis considering dynamic operator actions and accident management actions

2020 ◽  
Vol 52 (9) ◽  
pp. 1983-1989 ◽  
Author(s):  
Duško Kančev
Keyword(s):  
Sensitivity Analysis ◽  
Management Actions ◽  
Accident Management ◽  
Dynamic Operator

scholarly journals Accident Management Actions in an Upper-Head Small-Break Loss-of-Coolant Accident with High-Pressure Safety Injection Failed

2011 ◽  
Vol 175 (3) ◽  
pp. 572-593 ◽  
Author(s):  
César Queral ◽  
Juan González-Cadelo ◽  
Gonzalo Jimenez ◽  
Ernesto Villalba
Keyword(s):  
High Pressure ◽  
Management Actions ◽  
Loss Of Coolant Accident ◽  
Accident Management ◽  
Loss Of Coolant

scholarly journals Testing a river basin model with sensitivity analysis and autocalibration for an agricultural catchment in SW Finland

2009 ◽  
Vol 18 (3-4) ◽  
pp. 428-439 ◽  
Author(s):  
S. TATTARI ◽  
J. KOSKIAHO ◽  
I. BÄRLUND
Keyword(s):  
Sensitivity Analysis ◽  
River Basin ◽  
Swat Model ◽  
Protective Measure ◽  
Background Information ◽  
Cultivated Plants ◽  
Nutrient Loads ◽  
Management Options ◽  
Modeling Tools ◽  
Management Actions

Modeling tools are needed to assess (i) the amounts of loading from agricultural sources to water bodies as well as (ii) the alternative management options in varying climatic conditions. These days, the implementation of Water Framework Directive (WFD) has put totally new requirements also for modeling approaches. The physically based models are commonly not operational and thus the usability of these models is restricted for a few selected catchments. But the rewarding feature of these process-based models is an option to study the effect of protection measures on a catchment scale and, up to a certain point, a possibility to upscale the results. In this study, the parameterization of the SWAT model was developed in terms of discharge dynamics and nutrient loads, and a sensitivity analysis regarding discharge and sediment concentration was made. The SWAT modeling exercise was carried out for a 2nd order catchment (Yläneenjoki, 233 km2) of the Eurajoki river basin in southwestern Finland. The Yläneenjoki catchment has been intensively monitored during the last 14 years. Hence, there was enough background information available for both parameter setup and calibration. In addition to load estimates, SWAT also offers possibility to assess the effects of various agricultural management actions like fertilization, tillage practices, choice of cultivated plants, buffer strips, sedimentation ponds and constructed wetlands (CWs) on loading. Moreover, information on local agricultural practices and the implemented and planned protective measures were readily available thanks to aware farmers and active authorities. Here, we studied how CWs can reduce the nutrient load at the outlet of the Yläneenjoki river basin. The results suggested that sensitivity analysis and autocalibration tools incorporated in the model are useful by pointing out the most influential parameters, and that flow dynamics and annual loading values can be modeled with reasonable accuracy with SWAT. Sensitivity analysis thus showed the parameters which should be known better in order to result in more realistic parameter values. Moreover, the scenario runs for CWs made with SWAT revealed the high demand of land area for this protective measure to be substantially effective.;

Vital rate sensitivity analysis as a tool for assessing management actions for the desert tortoise

2009 ◽  
Vol 142 (11) ◽  
pp. 2710-2717 ◽  
Author(s):  
J. Michael Reed ◽  
Nina Fefferman ◽  
Roy C. Averill-Murray
Keyword(s):  
Sensitivity Analysis ◽  
Rate Sensitivity ◽  
Vital Rate ◽  
Desert Tortoise ◽  
Management Actions

The PSI Artist Project: Aerosol Retention and Accident Management Issues Following a Steam Generator Tube Rupture

2002 ◽  
Author(s):  
Salih Gu¨ntay ◽  
Abdel Dehbi ◽  
Detlef Suckow ◽  
Jon Birchley
Keyword(s):  
Steam Generator ◽  
Tube Bundle ◽  
Severe Accident ◽  
Pressurized Water ◽  
Steam Generator Tube ◽  
Full Size ◽  
Management Actions ◽  
Accident Management ◽  
Dry Conditions ◽  
Secondary Side

Steam generator tube rupture (SGTR) incidents, such as those, which occurred in various operating pressurized, water reactors in the past, are serious operational concerns and remain among the most risk-dominant events. Although considerable efforts have been spent to understand tube degradation processes, develop improved modes of operation, and take preventative and corrective measures, SGTR incidents cannot be completely ruled out. Under certain conditions, high releases of radionuclides to the environment are possible during design basis accidents (DBA) and severe accidents. The severe accident codes’ models for aerosol retention in the secondary side of a steam generator (SG) have not been assessed against any experimental data, which means that the uncertainties in the source term following an unisolated SGTR concurrent with a severe accident are not currently quantified. The accident management (AM) procedures aim at avoiding or minimizing the release of fission products from the SG. The enhanced retention of activity within the SG defines the effectiveness of the accident management actions for the specific hardware characteristics and accident conditions of concern. A sound database on aerosol retention due to natural processes in the SG is not available, nor is an assessment of the effect of management actions on these processes. Hence, the effectiveness of the AM in SGTR events is not presently known. To help reduce uncertainties relating to SGTR issues, an experimental project, ARTIST (AeRosol Trapping In a Steam generaTor), has been initiated at the Paul Scherrer Institut to address aerosol and droplet retention in the various parts of the SG. The test section is comprised of a scaled-down tube bundle, a full-size separator and a full-size dryer unit. The project will study phenomena at the separate effect and integral levels and address AM issues in seven distinct phases: Aerosol retention in 1) the broken tube under dry secondary side conditions, 2) the near field close to break under dry conditions, 3) the bundle far-field under dry conditions, 4) the separator and dryer under dry conditions, 5) the bundle section under wet conditions, 6) droplet retention in the separator and dryer sections and 7) the overall SG (integral tests). Prototypical test parameters are selected to cover the range of conditions expected in severe accident as well as DBA scenarios. This paper summarizes the relevant issues and introduces the ARTIST facility and the provisional test program which will run between 2003 and 2007.

3533 A ROSA-V Experimental Study on PWR Accident Management Actions and Role of Reactor Instrumentation

2005 ◽  
Vol 2005.3 (0) ◽  
pp. 223-224
Author(s):  
Mitsuhiro SUZUKI ◽  
Takeshi TAKEDA ◽  
Hideaki ASAKA ◽  
Hideo NAKAMURA
Keyword(s):  
Experimental Study ◽  
Management Actions ◽  
Accident Management

Accident Management Actions in a Lower Head SBLOCA With HPSI Failed

2012 ◽  
Author(s):  
J. Gonzalez-Cadelo ◽  
C. Queral ◽  
J. Montero ◽  
J. C. Martinez-Murillo
Keyword(s):  
High Pressure ◽  
Time Delays ◽  
Safety Assessment ◽  
Nuclear Safety ◽  
Safety Issues ◽  
Management Actions ◽  
Accident Management ◽  
Lower Head ◽  
Emergency Operating ◽  
Present Emergency

In the framework of CAMP and OECD/NEA ROSA projects a broad analysis of Lower Head SBLOCA with High Pressure Safety Injection (HPSI) unavailable in a Westinghouse PWR has been performed. The simulations have been performed with TRACE 5 patch1 and the selected methodology has been the Integrated Safety Assessment (ISA) methodology, developed by the Spanish Nuclear Safety Council (CSN), which allows obtaining the damage domain as a function of the operator actuation times. The objective of this work is to find the available time for accident management actions by means of ISA methodology. The main conclusions are that present emergency operating procedures are adequate for this kind of sequences and there is not necessary to modify them and also that, the ISA methodology is adequate to analyze safety issues that include time delays uncertainties.

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