scholarly journals 5.0. Depletion, activation, and spent fuel source terms

2016 ◽  
Author(s):  
William A. Wieselquist
Keyword(s):  
Source Terms ◽  
Spent Fuel ◽  
Fuel Source

Assessment of Radiological Source Term Releases for Potential Severe Accident Scenarios in a PWR SFP

2018 ◽  
Author(s):  
Kwang-Il Ahn ◽  
Jae-Uk Shin
Keyword(s):  
Water Injection ◽  
Severe Accident ◽  
Base Case ◽  
Source Terms ◽  
Spent Fuel ◽  
Fukushima Accident ◽  
Pressurized Water ◽  
Makeup Water ◽  
Accident Scenarios ◽  
The Impact

The primary purpose of this study is to assess the release of source terms into the environment for representative spent fuel pool (SFP) severe accident scenarios in a reference pressurized water reactor (PWR). For this, two typical accident scenarios (loss-of-cooling and loss-of-pool-inventory accidents) and two different reactor operating modes (normal and refueling modes) are considered in the analysis. The secondary purpose of this study is to assess the impact of an emergency makeup water injection strategy, which is one of representative SFP severe accident mitigation (SAM) strategies being employed after the Fukushima accident, upon the release of the radiological source terms. A total of 16 cases, consisting of four base cases and three injection cases for each base case were simulated using the MELCOR1.8.6 SFP version. The, analysis results are given in terms of (a) the key thermal-hydraulic behaviors during an accident progression and (b) releases of radiological fission products (such as Cesium and Iodine) into the environment. In terms of a release of Cesium and Iodine into the environment, the present study show that the two cases subject to a loss of pool inventory (i.e., LOPI-N-03 and LOPI-R-00) lead to the worst results with the respective release fractions of 77.5% and 59.4%.

scholarly journals MELCOR Demonstration Analysis of Accident Scenarios at a Spent Nuclear Reprocessing Plant

2020 ◽  
Author(s):  
Kenneth C. Wagner ◽  
David L. Y. Louie
Keyword(s):  
Source Term ◽  
Model Development ◽  
Source Terms ◽  
Spent Fuel ◽  
Nuclear Facilities ◽  
Demonstration Analysis ◽  
Nuclear Reprocessing ◽  
Probabilistic Risk Assessments ◽  
Accident Scenarios ◽  
Reprocessing Plant

Abstract The work presented in this paper applies the MELCOR code developed at Sandia National Laboratories to evaluate the source terms from potential accidents in non-reactor nuclear facilities. The present approach provides an integrated source term approach that would be well-suited for uncertainty analysis and probabilistic risk assessments. MELCOR is used to predict the thermal-hydraulic conditions during fires or explosions that includes a release of radionuclides. The radionuclides are tracked throughout the facility from the initiating event to predict the time-dependent source term to the environment for subsequent dose or consequence evaluations. In this paper, we discuss the MELCOR input model development and the evaluation of the potential source terms from the dominated fire and explosion scenarios for a spent fuel nuclear reprocessing plant.

scholarly journals SENSITIVITY ANALYSIS OF PWR SPENT FUEL DUE TO MODELLING PARAMETER UNCERTAINTIES USING SURROGATE MODELS

2021 ◽  
Vol 247 ◽  
pp. 15009
Author(s):  
Bamidele Ebiwonjumi ◽  
Peng Zhang ◽  
Deokjung Lee
Keyword(s):  
Sensitivity Analysis ◽  
Fuel Assembly ◽  
Spent Nuclear Fuel ◽  
Nuclear Data ◽  
Surrogate Models ◽  
Source Terms ◽  
Spent Fuel ◽  
Parameter Uncertainties ◽  
Pressurized Water ◽  
Sensitivity Indices

In the BEPU (Best Estimate Plus Uncertainty) framework, uncertainty quantification (UQ) is a requirement to improve confidence and reliability of code predictions. Over the years, a lot of works have been done to quantify uncertainties in code predictions of spent nuclear fuel (SNF) characteristics due to nuclear data uncertainties. The purpose of this study is to quantify the uncertainty in pressurized water reactor (PWR) fuel assembly radiation source terms (isotopic inventory, activity, decay heat, neutron and gamma source) due to uncertainties in modeling parameters. The deterministic code STREAM is used to predict the source terms of a typical PWR fuel assembly following realistic and detailed irradiation history. For the sensitivity analysis (SA) and UQ, surrogate models are developed based on polynomial chaos expansion (PCE) and variance-based global sensitivity indices (i.e., Sobol’ indices) are employed. The global SA identifies the less important uncertain parameters, showing that the number of uncertain input parameters can be reduced. The surrogate model offers a significantly reduced computational burden even with large number of samples required for the SA/UQ of the model response.

scholarly journals ORIGAMI Automator Primer. Automated ORIGEN Source Terms and Spent Fuel Storage Pool Analysis

2016 ◽  
Author(s):  
William A. Wieselquist ◽  
Adam B. Thompson ◽  
Stephen M. Bowman ◽  
Joshua L. Peterson
Keyword(s):  
Pool Analysis ◽  
Source Terms ◽  
Spent Fuel ◽  
Storage Pool ◽  
Spent Fuel Storage ◽  
Fuel Storage

Source Trends for Performance Assessment of HLW Glass and Spent Fuel as Waste Forms

1997 ◽  
Vol 506 ◽  
Author(s):  
B. Grambow
Keyword(s):  
Mass Transfer ◽  
Performance Assessment ◽  
Source Term ◽  
Reaction Rates ◽  
Dissolution Mechanism ◽  
Experimental Measurements ◽  
Source Terms ◽  
Spent Fuel ◽  
Fuel Oxidation ◽  
Waste Forms

ABSTRACTwith respect to the state of validation for source term development. Consequences of the various mechanism on mass half lives of the waste forms are calculated with analytical equations. For glass the largest uncertainty stems from the yet unclear dissolution mechanism under silica saturated conditions. Source terms based on silica solubility coupled to Si-mass transfer are probably neither conservative nor realistic. For spent fuel the largest uncertainty is in the extrapolation of radiolytic fuel oxidation for long periods of time. Considering the uncertainties involved, reaction rates cannot yet be extrapolated reliably to values much lower than the lowest reliable experimental measurements.

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