By combining the flexibility of a general-purpose and highly-graphical probabilistic simulation framework with a specialized module to support radionuclide transport modeling, GoldSim allows you to create realistic models of complex, real-world multi-media environmental systems.
Because of these powerful capabilities, GoldSim is the premier tool in the world for carrying out probabilistic performance and safety assessments of proposed and existing radioactive waste management sites. These performance assessments all utilize the GoldSim Radionuclide Transport (RT) Module, which includes specialized and powerful features to facilitate simulation of radionuclide transport through engineered barriers and the environment.
GoldSim can accurately and efficiently model complex processes such as decay and ingrowth of reaction/decay products, solubility constraints, sorption onto porous media, release from engineered barriers, diffusive trainsport, and transport of contaminants on particulates.
GoldSim was originally applied to evaluating the performance of radioactive waste disposal systems in the US (US Department of Energy), Japan (JAEA) and Spain (Enresa). It has subsequently been used by government and commercial organizations to model existing and proposed facilities in nearly 20 countries worldwide.
Development of an Execution Strategy Analysis Capability and Tool for Storage of Used Nuclear Fuel
Publication for the International Atomic Energy Agency, IAEA-CN-226-34 – June 2015
R. Stoll, J. Greeves, and J. Voss with Predicus LLC, USA; A. Keizur and A. Neir with Golder Associates Inc., USA; N. Saraeva and W. Nutt with Argonne National Laboratory, USA
An Execution Strategy Analysis (ESA) capability and tool is being developed to evaluate alternative execution strategies for future deployment of a consolidated Interim Storage Facility (ISF) using a consent-based siting process per the Administration’s Strategy for the Management and Disposal of Used Nuclear Fuel and High-Level Radioactive Waste. Application of an ESA approach not only leverages on but also goes beyond traditional project analysis tools. The ESA tool allows for on-going performance assessment of the evolving project execution plan that takes into account significant assumptions, risks, and uncertainties throughout the project lifecycle. The ESA process and tool are used to support the development of plans, budgets, and alternative execution/ implementation strategies for meeting the goals in the Strategy. The project is being applied in a dynamic probabilistic simulation model using GoldSim.
Safety Assessment for the Radon-Type Surface Disposal Facility at Saakadze, Georgia
Conference Proceedings, WM2015 Conference, Phoenix, Arizona, USA – March, 2015
Bernt Haverkamp, DBE Technology GmbH and Heinz Kroeger, TÜV NORD EnSys Hannover
The Saakadze disposal facility is located about 40 km from Tbilisi and was planned and constructed during Soviet times as Radon-type surface facility to accommodate up to 600 m3 of low and intermediate level waste generated on the territory of Georgia. The disposal facility was operated from 1963 until its closure in 1995. The vast majority of waste in the Saakadze facility has been disposed of in two near surface concrete vaults with typical Radon-type dimensions, which cover layers already show significant structural damages. For the long-term calculations a mathematical model has been developed using the GoldSim simulation environment. GoldSim simulates the material transport and takes care of radioactive decay and the ingrowth of daughter nuclides.
Preliminary Performance Assessment for the Waste Management Area C at the Hanford Site in Southeast Washington
TOC-WP-14-4902 -FP Revision 0, Prepared for the U.S. DOE – January 2015
M. Bergeron, S. Mehta, W.J. McMahon, M. Kozak, A. Aly, M. Connelly, K. Singleton, S. Eberlein, C. Kemp, and R.D. Hildebrand
A performance assessment (PA) of a Single-Shell Tank Waste Management Area located at the U.S. Department of Energy's (DOE) Hanford Site in southeastern Washington is being conducted to fulfill permitting requirements. Uncertainty and sensitivity analyses using a system level GoldSim model is being used to help quantify the importance of key input parameters on transport behavior and dose.
Modelling of Contaminant Release from a Uranium Mine Tailings Site
Proceedings of the 11th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM) – September 2007
R. Kahnt and T. Metschies
Uranium mining and milling continuing from the early 1960s until 1990 close to the town of Seelingstädt in Eastern Germany resulted in 4 large tailings impoundments. Leakage from these tailings impoundments enters the underlying aquifers and is discharged into surface water streams. High concentration of salts, uranium and several heavy metals are released from the tailings. A compartment model representing the tailings impoundments and the surrounding aquifers for the calculation of contaminant release and transport was set up using GoldSim. This compartment model describes the time dependent hydraulic conditions within the tailings and the surrounding aquifers taking into account hydraulic and geotechnical processes influencing the hydraulic properties of the tailings material. A simple geochemical approach taking into account sorption processes as well as retardation by applying a kd-approach was also implemented. The model was used to predict the effect of various remediation scenarios in a fast and traceable way.
Prioritization Risk Integration Simulation Model (PRISM) for Environmental Remediation and Waste Management
WM2012 Conference, Phoenix, AZ – February 2012
David L. Pentz, Ralph H. Stoll, John T . Greeves, Predicus LLC; R. Ian Miller, GoldSim Technology Group; W. Mark Nutt, Argonne National Laboratory
The PRISM (Prioritization Risk Integration Simulation Model), a computer model was developed to support the Department of Energy's Office of Environmental Management (DOE-EM) in its mission to clean up the environmental legacy from the Nation’s nuclear weapons materials production complex. PRISM provides a comprehensive, fully integrated planning tool that can tie together DOE-EM's projects. It is designed to help DOE managers develop sound, risk-informed business practices and defend program decisions. It provides a better ability to understand and manage programmatic risks.
GoldSim Modeling for the Options Analysis for the Smoky Site, Nevada Test Site
Neptune and Company Project Report – July 2004
John Tauxe, Neptune and Company
This webpage describes a Neptune and Company project to develop a GoldSim model to assist in evaluating different options for maintaining power lines running through a contaminated area of the Nevada Test Site.
A Multipathway Model for High Explosives and Barium Transport Using GoldSim
Proceedings of the American Geophysical Union, Spring Meeting – May 2002
Los Alamos National Laboratory
This paper describes a GoldSim model developed to assist in characterizing, monitoring and possible remediation activities for an ecosystem contaminated by outfalls from high explosive production sites at the Los Alamos National Laboratory.
Predicting Risks in the Earth Sciences: Volcanological Examples
Los Alamos Science, Number 29, pgs. 56-69 – 2005
Greg Valentine, Los Alamos National Laboratory
This article describes the process of volcanological risk assessment, including describing how this is modeled, using GoldSim, within the Yucca Mountain Total System Performance Assessment.
Comparison of Uncertainty and Sensitivity Analyses Methods Under Different Noise Levels
Presentation, PSAM12: Probabilistic Safety Assessment & Management Conference – June 2014
David Esh and Christopher Grossman, US Nuclear Regulatory Commission
Uncertainty and sensitivity analyses are an integral part of probabilistic assessment methods used to evaluate the safety of a variety of different systems. In many cases the systems are complex, information is sparse, and resources are limited. Models are used to represent and analyze the systems. To incorporate uncertainty, the developed models are commonly probabilistic. Uncertainty and sensitivity analyses are used to focus iterative model development activities, facilitate regulatory review of the model, and enhance interpretation of the model results. A large variety of uncertainty and sensitivity analyses techniques have been developed as modeling has advanced and become more prevalent. This paper compares the practical performance of six different uncertainty and sensitivity analyses techniques over ten different test functions under different noise levels. In addition, insights from two real-world examples are developed.
GoldSim models of long-term radiation impact of conditionally cleared radioactive material
Progress in Nuclear Energy, Vol. 67, pgs. 88-97 – August 2013
Michal Panik and Vladimir Necas of Slovak University of Technology in Bratislava
The article is focused on modeling and calculation of long-term radiation impact on inhabitants living near decommissioned nuclear installations. Models (scenarios) of various building applications were simulated using GoldSim software with Radionuclide Transport Module. Scenarios were selected according to information from the civil engineering business to cover the types of buildings most suitable for application of conditionally cleared material. The results of the calculations showed that conditional clearance represents no significant safety issue in the long-term. Calculated individual effective doses received by inhabitants did not exceed the given dose constraint (10 μSv/year) in case of any scenario evaluated. Detailed and transparent studies of the long-term impact of conditionally cleared materials are important especially for winning of public acceptance.
Safety Assessment for a Surface Repository in the Chernobyl Exclusion Zone
Conference Proceedings, WM2013 Conference – February 2013
B. Haverkamp, J. Krone, I. Shybetskyi
The Radioactive Waste Disposal Facility (RWDF) Buryakovka was constructed in 1986 as part of the intervention measures after the accident at Chernobyl NPP (ChNPP). Today, RWDF Buryakovka is still being operated but its maximum capacity is nearly reached. Plans for enlargement of the facility exist since more than 10 years but have not been implemented yet. A safety analysis report of the facility in its current state (SAR) and a preliminary safety analysis report (PSAR) based on the planned enlargement were prepared. For both safety analysis reports, SAR and PSAR, the assessment of the long-term safety led to results that were either within regulatory limits or within the limits allowing for a specific situational evaluation by the regulator. The repository model was built in GoldSim to carry out the long-term calculations using the Radionuclide Transport Module, which takes not only care of the transport equations describing the mass transport between the different compartments of the model but also of radioactive decay and ingrowth of daughter nuclides with time.
Safety Assessment for the Kozloduy National Disposal Facility in Bulgaria
Conference Proceedings, WM2013 Conference – February 2013
E. Biurrun, A. Lázaro, I. Stefanova, B. Haverkamp, A. Miralles
Due to the early decommissioning of four Water-Water Energy Reactors (WWER) 440-V230 reactors at the Nuclear Power Plant (NPP) near the city of Kozloduy in Bulgaria, large amounts of low and intermediate radioactive waste will arise much earlier than initially scheduled. In or-der to manage the radioactive waste from the early decommissioning, Bulgaria has intensified its efforts to provide a near surface disposal facility at Radiana with the required capacity. To this end, a project was launched to provide the complete technical planning including the preparation of the Intermediate Safety Assessment Report. Preliminary results of operational and long-term safety show compliance with the Bulgarian regulatory requirements. The long-term calculations carried out for the Radiana site are also a good example of how analysis of safety assessment results can be used for iterative improvements of the assessment by pointing out uncertainties and areas of future investigations to reduce such uncertainties in regard to the potential radiological impact. GoldSim was used to estimate the long-term evolution of the future repository at Radiana predicted a maximum total annual dose for members of the critical group, which is carried to approximately 80 % by C-14 for a specific ingestion pathway. Based on this result and the outcome of the sensitivity analysis, existing uncertainties were evaluated and areas for reasonable future investigations to reduce these uncertainties were identified.
Risk Evaluation of a Mercury Containment System
FIU Electronic Theses Dissertations, Paper S35 – November 2011
Ortez Garay, Cristian A. (Florida International University)
This is a Master's Thesis describing the methodology used to estimate mercury concentrations and risk of exceeding drinking water standards at a receptor well, located near a waste management facility at the Oak Ridge Reservation in Tennessee. GoldSim was used to evaluate the risk based on uncertainty of hydrological and soil parameters used to estimate potential mercury releases from a future containment system. Sensitivity analysis was used to determine the parameters that the model is most sensitive to. Using Monte Carlo analysis, the risk was estimated for various design periods and the overall risk of drinking water contamination was well below standard limits.
Decision & Management Tools for DNAPL Sites: Optimization of Chlorinated Solvent Source and Plume Remediation Considering Uncertainty
Final Report, ESTCP Project ER-200704 – 2010
Falta, Ronald W.; Newell, Charles J.; Rao, P. Suresh C.; Liang, Hailian; Farhat, Shahla K.; Basu, Nandita
The objective of this project was to develop a new probabilistic remediation modeling program, Probabilistic Remediation Evaluation Model for chlorinated Solvents (PREMChlor), for simultaneously evaluating the effectiveness of source and plume remediation considering the uncertainties in all major parameters, thereby supporting the remediation selection process. PREMChlor was developed by linking the analytical model REMChlor to a Monte Carlo modeling package, GoldSim, via a FORTRAN Dynamic Link Library (DLL) application.
Code-to-Code Benchmarking of the PORFLOW and GoldSim Contaminant Transport Models
WM2011 Conference, Phoenix, AZ – March 2011
Robert Hiergesell and Glenn Taylor, Savannah River National Laboratory
An investigation was conducted to compare and evaluate contaminant transport results of two model codes, GoldSim and PORFLOW, using a simple 1-D string of elements in each code. The comparisons were made solely in terms of the ability of each code to perform contaminant transport. The purpose of the investigation was to establish a basis for, and to validate follow-on work that was conducted in which a 1-D GoldSim model developed by abstracting information from PORFLOW 2-D and 3-D unsaturated and saturated zone models and then benchmarked to produce equivalent contaminant transport results. Although prior validation and verification work has been conducted for both PORFLOW and GoldSim a direct comparison of results from both codes, when evaluating the same model domain, was conducted to confirm this work and justify the benchmarking exercises that compared 1-D to multi-dimensional models.
Understanding Controls on the Performance of Engineered Barrier Systems in Repositories for High-Level Radioactive Waste and Spent Fuel
Environment Agency Report SC060055 – September 2010
A. Bond, M.J. Egan, R. Metcalfe, P.Robinson, G.Towler (Quintessa)
The primary aim of this report was to summarize and analyse existing knowledge on processes that could influence the performance of an EBS and hence the long-term safety performance of a repository. After reviewing the safety functions attributed to various barrier components by radioactive waste management programmes across the world, and identifying groups of features, events and processes (FEPs) that describe these safety functions and threats to these safety functions, calculations using GoldSim were carried out to explore the significance of each of these FEPs as controls on the performance of barrier components.
The Development of a Safety Assessment Approach and its Implication on the Advanced Nuclear Fuel Cycle
Nuclear Engineering and Technology, Vol. 42, No. 1 – February 2010
Yongsoo Hwang and Chul-Hyung Kang, Korea Atomic Energy Research Institute
This paper discusses use of GoldSim to evaluate the potential radionuclide release from a repository based on the Advanced Korean Reference Disposal System (A-KRS). Among other advantages, the development of the A-KRS promises a significant reduction of the repository area due to the removal of decay heat from a certain number of fission products such as Sr-90 and Cs-137.
Modelling of Near-Field Radionuclide Transport Phenomena in a KBS-3V Type of Repository for Nuclear Waste with GoldSim Code - and Verification Against Previous Methods
Posiva Working Report 2010-14, Posiva Oy, Finland – March 2010
Veli-Matti Pulkkanen and Henrik Nordman
This report describes the use of GoldSim to model the near-field radionuclide transport processes in a KBS-3V type of nuclear waste repository in Finland.
A GoldSim Model for the Safety Assessment of a HLW Repository
Progress in Nuclear Energy Volume 51, Issues 6-7, pgs. 746-759 – August/September 2009
Youn-Myong Lee and Yongsoo Hwang, Korea Atomic Energy Research Institute
This article describes a GoldSim model of a hypothetical high level waste repository in South Korea, and describes the model's response to three hypothetical situations (groundwater intrusion, earthquake and accidental human intrusion).
Performance Assessment for Depleted Uranium Disposal in a Near-Surface Disposal Facility
Scientific Basis for Nuclear Waste Management XXXII, MRS Proceedings, Volume 1124 – Fall 2008
Karen Pinkston, David W. Esh, Christopher J. Grossman
This paper discusses a GoldSim model built by the U.S. Nuclear Regulatory Commission (NRC) to assess the potential impacts of disposal of large quantities of depleted uranium in a near-surface disposal facility.
Development of the ENVI Simulator to Estimate Korean SNF Flow and its Cost
Proceedings of the 12th International Conference on Environmental Remediation And Radioactive Waste Management ICEM 2009 – October 2009
Yongsoo Hwang and Ian Miller
This paper describes an integrated model developed by the Korean Atomic Energy Research Institute (KAERI) to simulate options for managing spent nuclear fuel (SNF) in South Korea.
GoldSim Modeling of the West Beach Landfill, Alameda Point, California
Neptune and Company Project Report – March 2002
John Tauxe, Neptune and Company
This web page describes a Neptune and Company project to evaluate remediation options for the West Beach Landfill on the grounds of the former Naval Air Station Alameda.
The page includes background on the project, and a link to a more detailed report on the model.
Developing Hazardous Waste Acceptance Criteria
Presentation – 2005
David Hall and David Drury, Golder Associates
This presentation describes the process of developing acceptance criteria for monolithic wastes.
A Comparative Study Between GoldSim and AMBER Based Biosphere Assessment Models for an HLW
Transactions of the Korean Nuclear Society Autmn Meeting, PyeongChang, Korea – October 2007
Youn-Myoung Lee and Yongsoo Hwang, Korea Atomic Energy Research Institute
To demonstrate the performance of a repository, GoldSim was used to examine the dose exposure rate to people due to long-term nuclide releases from a high-level waste repository and the results are compared to that of a similar model built in AMBER. The GoldSim model integrates the results of complex nuclide transport models through engineered barriers and geological fractured rock media surrounding an HLW repository site for a consecutive transport through a biosphere.
Update of the Safety Assessment Of The Underground Richard Repository, Litoměřice
Conference Proceedings, WM'05 Conference, Tucson, AZ. – March 2005
B. Haverkamp, E. Biurrun, with DBE TECHNOLOGY GmbH, and M. Kučerka with Radioactive Waste Repository Authority, Czech Republic
The Richard Repository, situated at the outskirts of Litoměřice in the North of Czech Republic, has served as a repository for low and intermediate level institutional radioactive waste since the mid nineteen-sixties. Up to now, some 25,000 waste packages and thereby a significant activity of about 1015 Bq have been disposed of. Richard, originally a limestone mine excavated into a hill close to the Elbe River, was later used for military production leaving a number of wellconditioned underground cavities.In order to quantify the radiological consequences of the changed closure concept, the 2002 SA has been adapted to acknowledge the differences in the source term resulting from the changed technical concept. Also the previously deterministic model has been exchanged by a computer model that also allows probabilistic calculations using the GoldSim
Do-or-Die at Yucca Mountain
Wired Magazine – November 2004
David Ewing Duncan
This Wired Magazine article provides a general overview of the Yucca Mountain project including a discussion of how GoldSim is used to try quantify the performance of the repository into the distant future.
Risks and Uncertainties Associated With High-Level Waste Tank Closure
Proceedings of the 2002 Materials Research Society Fall Meeting – Fall 2002
David Esh, Anna Bradford, Kristina Banovac, and Jennifer Davis, US Nuclear Regulatory Commission
This paper discusses a performance assessment model of closure of a radioactive waste tank developed by the Nuclear Regulatory Commission, using GoldSim, to independently verify results from a Department of Energy assessment of the same project.
A Systems Modeling Approach for Performance Assessment of the Mochovce National Radioactive Waste Repository, Slovak Republic
Geophysical Research Abstracts, Vol. 9, 05821 – 2007
John Tauxe and Paul Black, Neptune and Company; Vaclav Hanusik, VUJE Trnava, Inc.
This paper discusses the performance assessment of a low- and intermediate-level waste repository in the Slovak Republic.
GoldSim Modeling of the Greater Confinement Disposal Boreholes
Neptune and Company Project Report – March 2002
John Tauxe, Neptune and Company
This webpage describes a Neptune and Company project to model the performance of borehole-type disposal of low-level nuclear waste at the Nevada Test Site. The page includes background on the project and a general discussion of the model design and structure.
Management of the Area 5 Radioactive Waste Management Site using Decision-Based, Probabilistic Performance Assessment Modeling
Proceedings of the 2003 Waste Management Symposium – February 2003
Jhon Carilli, U. S. Department of Energy, National Nuclear Security Administration Nevada Site Office. Bruce Crowe, Los Alamos National Laboratory; Paul Black, John Tauxe, Tom Stockton, and Kate Catlett, Neptune and Company; Vefa Yucel, Bechtel Nevada
This paper describes performance assessment activity for low-level waste facilities at the Nevada Test Site.
Use of Simplified Models in the Performance Assessment of a High-Level Waste Repository System in Japan
Proceedings of the NUCEF2005 Symposium – February 2005
Osvaldo Pensado and Sitakanta Mohanty, Southwest Research Institute; Takeshi Kanno and Yoshikatsu Tochigi, Ishikawajima-Harima Heavy Industries Co., Ltd.
This paper and website describes a project to build a GoldSim model for a hypothetical high-level waste repository in Japan.
A Generic Example of Probabilistic Radiological Performance Assessment Modeling
Neptune and Company Project Report –
John Tauxe, Neptune and Company
This web page describes a generic performance assessment model developed in GoldSim for low-level radioactive waste disposal facilities.
Modelling of Processes Occurring in Deep Geological Repositories
Czechoslovak Journal of Physics, Volume 56, D623-D628 – December 2006
D. Vopálka, Czech Technical University in Prague; D. Lukin and A. Vokál, Nuclear Research Institute Rez
This paper describes GoldSim modeling techniques for several different processes that occur in a deep geologic repository for the storage of nuclear waste.
Probabilistic Sensitivity Analysis for the "Initial Defect in the Canister" Reference Model
Workreport 2013-25, Posiva Oy, Eurajoki, Finland – August 2013
Jose Luis Cormenzana
In Posiva Oy´s Safety Case "TURVA-2012", the repository system scenarios leading to radionuclide releases were been identified. Three potential causes of canister failure and radionuclide release were considered: (i) the presence of an initial defect in the copper shell of one canister that penetrates the shell completely, (ii) corrosion of the copper overpack, that occurs more rapidly if buffer density is reduced, e.g. by erosion, (iii) shear movement on fractures intersecting the deposition hole. All three failure modes were analysed deterministically. This report describes a probabilistic sensitivity analysis (PSA) for the "initial defect in the canister" reference model.
SOAR: A Model For Scoping Of Options And Analyzing Risk Version 1.0 User Guide
Report prepared for U.S. Nuclear Regulatory Commission Contract No. NRC–02–07–006 – August 2011
Chris Markely et al. (U.S. Nuclear Regulatory Commission)
This document is a user guide that describes the operation and capabilities of the Scoping of Options and Analyzing Risk (SOAR) model. The SOAR model is designed to provide the U.S. Nuclear Regulatory Commission (NRC) staff timely risk and performance insights for a variety of potential high-level radioactive waste (HLW) disposal options. The SOAR model is an analytic scoping tool that the staff will use to develop an effective and efficient risk-informed, performance-based licensing program for geologic disposal of HLW.
The 2011 Environmental Safety Case: Assessment of Long-Term Radiological Impacts
LLWR/ESC/R(11)10028 – May 2011
LLW Repository Ltd
The Low Level Waste Repository (LLWR) is the United Kingdom’s principal facility for the disposal of solid low-level radioactive waste. The LLWR is owned by the Nuclear Decommissioning Authority (NDA) and operated on behalf of the NDA by a Site Licence Company (SLC) – LLW Repository Ltd.
This report is one of a series of reports that present the evidence underpinning the 2011 Environmental Safety Case for the LLWR – the 2011 ESC. The objective of this report is to assess the radiological impacts to humans that may occur in the long term, as a result of disposal of solid radioactive waste at the LLWR.
Prioritization Risk Integration Simulation Model (PRISM) For Environmental Remediation and Waste Management
WM2012 Conference, Phoenix, Arizona, USA – February 26 – March 1, 2012
David L. Pentz, Ralph H. Stoll, John T. Greeves, R. Ian Miller, and W. Mark Nutt
The PRISM (Prioritization Risk Integration Simulation Model), a computer model was developed to support the Department of Energy’s Office of Environmental Management (DOE-EM) in its mission to clean up the environmental legacy from the Nation’s nuclear weapons materials production complex. PRISM provides a comprehensive, fully integrated planning tool that can tie together DOE-EM’s projects. It is designed to help DOE managers develop sound, risk-informed business practices and defend program decisions. It provides a better ability to understand and manage programmatic risks. The underlying concept for PRISM is that DOE-EM “owns” a portfolio of environmental legacy obligations (ELOs), and that its mission is to transform the ELOs from their current conditions to acceptable conditions, in the most effective way possible. There are many types of ELOs - - contaminated soils and groundwater plumes, disused facilities awaiting D&D, and various types of wastes waiting for processing or disposal. For a given suite of planned activities, PRISM simulates the outcomes as they play out over time, allowing for all key identified uncertainties and risk factors.
PRISM is based on the GoldSim software that is widely used for risk and performance assessment calculations. PRISM can be run in a deterministic mode, which quickly provides an estimate of the most likely results of a given plan. Alternatively, the model can be run probabilistically in a Monte Carlo mode, exploring the risks and uncertainties in the system and producing probability distributions for the different performance measures.
Post-Closure Safety Assessment of Near Surface Disposal Facilities for Disused Sealed Radioactive Sources
Nuclear Engineering and Design – March 2017
Seunghee Lee and Juyoul Kim, FNC Technology Co.
Great attention has been recently paid to the post-closure safety assessment of low- and intermediate-level radioactive waste (LILW) disposal facility for disused sealed radioactive sources (DSRSs) around the world. Although the amount of volume of DSRSs generated from industry, medicine and research and education organization was relatively small compared with radioactive wastes from commercial nuclear power plants, some DSRSs can pose a significant hazard to human health due to their high activities and long half-lives, if not appropriately managed and disposed. In this study, post-closure safety assessment was carried out for DSRSs generated from 1991 to 2014 in Korea in order to ensure long-term safety of near surface disposal facilities. Two kinds of disposal options were considered, i.e., engineered vault type disposal facility and rock-cavern type disposal facility. Rock-cavern type disposal facility has been under operation in Gyeongju city, republic of Korea since August 2015 and engineered vault type disposal facility will be constructed until December 2020 in the vicinity of rock-cavern disposal facility. Assessment endpoint was individual dose to the member of critical group, which was modeled by GoldSim, which has been widely used as probabilistic risk analysis software based on Monte Carlo simulation in the area of safety assessment of radioactive waste facilities.
The Introduction of the Safety Assessment of HLW Disposal in 2014–2017 in China
Proceedings of The 20th Pacific Basin Nuclear Conference. PBNC 2016. – February 2017
Hong-hui Li, China Institute for Radiation Protection
In China, “The Law on Prevention and Control for Radioactive Pollution” issued in 2003 determined that the high-level waste will be disposed in a deep central geological repository. The main work of China Institute for Radiation Protection (CNNC-mandated comprehensive research) about HLW disposal is safety assessment. In 2006–2010, the CIRP have done some of the works about safety criteria and safety requirements: public radiation protection for post-closure of repository: 0.3 mSv/a; timescale: 10,000a. The CIRP also have established SA methodology and routine. Some software about safety assessment such as AMBER, Ecolegy, GoldSim, ProFlow can be familiarly used. The main works in 2014–2017 about the safety assessment that will be done are the research of safety requirements of the EBS and host rock, the research of safety function of the EBS and host rock, establishing the safety indicators’ system of the EBS and host rock, establishing the FEPs list and the scenario analysis in the conceptual and planning stage, the near-field temperature simulation based on the conceptual design of the repository, and the safety assessment of Beishan Preliminary Repository. Some of the above-mentioned work details will be introduced in this paper.
GoldSim's Dynamic-Link Library (DLL) Interface for Cementitious Barriers Partnership (CBP)
WM2011 Proceedings – March 2011
Kevin G. Brown, Vanderbilt University; Frank Smith and Gregory Flach, Savannah River National Laboratory
The Cementitious Barriers Partnership (CBP) Project is a multi-disciplinary, multi-institutional collaboration supported by the United States Department of Energy (US DOE) Office of Waste Processing. The objective of the CBP project is to develop a set of tools to improve understanding and prediction of the long-term structural, hydraulic, and chemical performance of cementitious barriers used in nuclear applications. The project is focused on reducing the uncertainties of current methodologies for assessing cementitious barrier performance and increasing the consistency and transparency of the assessment process. To better characterize the uncertainties in the models used to predict barrier performance, GoldSim is used as a probabilistic framework with interfaces to external codes for specific calculations. A general dynamic-link library (DLL) interface has been developed to link GoldSim with external codes. The DLL that performs the linking function is designed to take a list of code inputs from GoldSim, create an input file for the external application, run the external code, and return a list of outputs, read from files created by the external application, back to GoldSim for analysis. Although currently used by CBP, the DLL is generic and can be used for a wide variety of external codes that need to be examined probabilistically. Use of the DLL to couple external codes to GoldSim helps enable improved risk-informed, performance-based decision-making and supports several of the strategic initiatives in the DOE Office of Environmental Management Engineering & Technology Roadmap.
Long-term Environmental Assessment of Waste from PyroGreen System
Procedia Chemistry – 2016
Heejae Ju, Inhye Hahm, Sungjune Sohn, and Il Soon Hwang, Seoul National University
We have conducted a long-term environmental assessment of a geological repository for Intermediate Level Wastes (ILW) arising from PyroGreen processes that has been developed to decontaminate all HLW from the pyrochemical partitioning of spent nuclear fuels (SNF). PyroGreen process has been designed so that final ILW can meet conservative acceptance criteria such as one established for the Waste Isolation Pilot Plant (WIPP) in U.S.A. The nuclide inventory of final vitrified PyroGreen waste is calculated using ORIGEN 2.1 based on the design decontamination factor of PyroGreen processes applied to 18,171 metric tons of PWR SNF with 45 GWD/MTU burnup. Using GoldSim model, the environmental impact of ILW upon geological disposal at an intermediate depth. Among radioactive nuclides, Ra226, Rn222 and Sn126 are identified as key contributors to radiological dose for general public. The environmental impact of PyroGreen wastes satisfies the Korean dose limit of 0.1 mSv/year with sufficiently high margin. Sensitivity studies have shown that the predicted dose can vary significantly by distribution coefficient of Ra226 and Rn222, solubility limit of Se79.
Sorbent Materials for Rapid Remediation of Wash Water during Radiological Event Relief
Chemosphere – November 2016
Jolin WC, University of Connecticut; Kaminski M, Argonne National Laboratory
Procedures for removing harmful radiation from interior and exterior surfaces of homes and businesses after a nuclear or radiological disaster may generate large volumes of radiologically contaminated waste water. Rather than releasing this waste water to potentially contaminate surrounding areas, it is preferable to treat it onsite. Retention barrels are a viable option because of their simplicity in preparation and availability of possible sorbent materials. This study investigated the use of aluminosilicate clay minerals as sorbent materials to retain (137)Cs, (85)Sr, and (152)Eu. To simulate flow within retention barrels, vermiculite was mixed with sand and used in small-scale column experiments. The GoldSim contaminate fate module was used to model breakthrough and assess the feasibility of using clay minerals as sorbent materials in retention barrels.
Preliminary Post-closure Safety Assessment of Disposal Options for Disused Sealed Radioactive Source
Economic and Environmental Geology – August 2016
Seunghee Lee, Juyoul Kim and Sukhoon Kim, FNC Technology Co.
Disused Sealed Radioactive Sources (DSRSs) are stored temporally in the centralized storage facility of Korea Radioactive Waste Agency (KORAD) and planned to be disposed in the low- and intermediate-level radioactive waste (LILW) disposal facility in Gyeongju city. In this study, preliminary post-closure safety assessment was performed for DSRSs in order to draw up an optimum disposal plan. Two types of disposal options were considered, i.e. engineered vault type disposal and rock cavern type disposal which were planned to be constructed and operated respectively in LILW disposal facility in Gyeongju city. Assessment end-point was individual effective dose of critical group and calculated by using GoldSim code.
A Preliminary Comparison Study of Two Options for Disposal of High-Level Waste
Progress in Nuclear Energy – July 2016
Youn-Myoung Lee, Heui-Joo Choi, and Kyungsu Kim, Korea Atomic Energy Research Institute (KAERI)
To compare two options for disposal of spent nuclear fuels (SFs) a generic GoldSim model for deep boreholes for disposal (DBD) of SFs was developed. As a desktop study, nuclide release and transport from a DBD after the closure of a repository were roughly evaluated and compared to a KBS-3 type disposal in a less deep geological repository (DGD). An assessment result from the DBD is shown to be remarkable and seems to give a sufficient radiological safety margin, compared to the DGD, even though this study was done in a very straightforward manner. A remarkable sensitivity of the travel lengths involved in the fractured geological media around the DBD to the exposure dose rates are not observed with rather fast and short travel times for non-sorbing nuclides with long-half lives.
Progress of the Long-Term Safety Assessment of a Reference Disposal System for High Level Wastes in Korea
Progress in Nuclear Energy – July 2016
Jongtae Jeong, Youn-Myoung Lee, Jung-Woo Kim, Dong-Keun Cho, Nak Yul Ko, and Min Hoon Baik, Korea Atomic Energy Research Institute (KAERI)
KAERI developed a reference repository system for the disposal of radioactive wastes resulting from the pyroprocessing of PWR spent nuclear fuels (A-KRS; Advanced Korean Reference Disposal System). To check the design feasibility of this system, we developed a total system performance assessment (TSPA) tool using Goldsim program and assessed the exposure dose rates for the reference scenario and three alternative scenarios such as earthquake, well intrusion, and initial defect of waste packages by using this tool. And then, we compared the exposure dose rates for each scenario with a draft supplementary safety goal, 10 mSv/yr, which was suggested by the regulatory body in Korea.
An Evaluation of Nuclide Release from a Trench-Type LILW Repository
Progress in Nuclear Energy – April 2016
Youn-Myoung Lee, Heui-Joo Choi, Korea Atomic Energy Research Institute (KAERI)
A simple and effective model and a GoldSim template program, by which a probabilistic safety assessment of a conceptual trench-type repository for low- and intermediate level radioactive waste (LILW) disposal can be carried out under various nuclide release scenarios, have been developed. To quantify the exposure dose rates due to nuclide release from the trench and transport through the various pathways possible in the near- and far-fields of the repository system under a base case and some alternative scenarios, illustrative evaluations for a comparison among the scenarios as well as a sensitivity of shortcut pathways generated due to earthquakes on the nuclide transport are made and demonstrated. To this end, by changing the conservative base case nuclide release scenario under which all portions of the cap of the trench are failed unconditionally and immediately after a closure of the repository, a total of four other alternative scenarios were separately evaluated for the total exposure dose rates to the farming exposure group and then compared to the base case results.
Radial Diffusion of Radiocaesium and Radioiodide through Cementitious Backfill
Physics and Chemistry of the Earth – April 2014
M. Felipe-Sotelo, J. Hinchliff, N.D.M. Evans, D. Read, Loughborough University; D. Drury, Golder Associates; S. Williams, Nuclear Decommissioning Authority
The function of the backfill material in a geological disposal facility (GDF) is to chemically condition the environment of the near field and thereby chemically retard the transport of the radionuclides present in the waste. This function of the backfill material is usually referred to as chemical containment. Diffusion experiments are being carried out over periods up to four years to assess the diffusion of Cs, Ni, Eu, Th, U and I (as I−) through Nirex Reference Vault Backfill (NRVB). This paper shows the results obtained during the first two years for experiments undertaken using 137Cs and 125I− tracers with and without carrier. Comparison is made to tritiated water under identical experimental conditions. Migration profiles have been obtained and the relative retention of each radionuclide has been confirmed using digital autoradiography. Transport modelling using GoldSim has replicated experimental observations, producing comparable partition ratios (Rd) to those reported in the literature.
Integration of Models for the Hanford Integrated Disposal Facility Performance Assessment
Proceedings of the 2018 Waste Management Symposium – March 2018
K.P. Lee, R. Andrews, N. Hasan, R. Senger, M. Kozak, A. K. Wahi, and W. Zhou
The US Department of Energy (DOE) Office of River Protection and its subcontractors performed a performance assessment for the near-surface disposal of low-level and mixed low-level waste at the Hanford Integrated Disposal Facility. Computer simulations were performed to evaluate whether or not the disposal facility would comply with the performance objectives specified by the DOE. The evaluation was performed using numerical models to simulate source term releases from vitrified and cement-based waste forms. Source term releases were subsequently transported through the facility into the natural system beneath the facility (comprised of an 85-meter thick vadose zone and thinner but highly conductive saturated zone overlying basalt) to a point of compliance 100-meters downstream the disposed waste. Due to the differing scales in the finite difference models developed for the source terms and those developed for the natural system, numerical models for source term release and natural system flow and transport were not directly coupled. Instead, the output from the source term simulations were used as input to the natural system flow and transport simulations. The decoupling of the modeled systems makes it difficult to explore synergies and investigate the impact of parameter uncertainties. In order to explore system synergies and evaluate parameter uncertainty, an integrated system model was developed using GoldSim that includes source term release models, natural system transport models, and dose calculations. This paper describes how the numerical models were used to develop abstractions that could be incorporated into the integrated system-level model that was then used to explore system synergies and parameter uncertainties.
Radioactive high level waste insight modelling for geological disposal facilities
Physics and Chemistry of the Earth – July 2013
Alexander Carter, Martin Kelly, and Lucy Bailey, Nuclear Decommissioning Authority
This paper presents a simplified analytical model to provide insight into the key performance measures of a generic disposal system for high level waste within a geological disposal facility. The model assumes a low solubility waste matrix within a corrosion resistant disposal container surrounded by a low permeability buffer. Radionuclides migrate from the disposal area through a porous geosphere to the biosphere and give a radiological dose to a receptor. The system of equations describing the migration is transformed into Laplace space and an approximation used to determine peak values for the radionuclide mass transfer rate entering the biosphere. Results from the model are compared with those from more detailed numerical models for key radionuclides in the UK high level waste inventory. Such an insight model can provide a valuable second line of argument to assist in confirming the results of more detailed models and build confidence in the safety case for a geological disposal facility.
An innovative method for determining the diffusion coefficient of product nuclide
Nuclear Engineering and Technology – August 2017
Chih-Lung Chen, Taiwan Power Company; Tsing-Hai Wang, National Tsing Hua University
Diffusion is a crucial mechanism that regulates the migration of radioactive nuclides. In this study, an innovative numerical method was developed to simultaneously calculate the diffusion coefficient of both parent and, afterward, series daughter nuclides in a sequentially reactive through-diffusion model. Two constructed scenarios, a serial reaction (RN_1 → RN_2 → RN_3) and a parallel reaction (RN_1 → RN_2A + RN_2B), were proposed and calculated for verification. First, the accuracy of the proposed three-member reaction equations was validated using several default numerical experiments. Second, by applying the validated numerical experimental concentration variation data, the as-determined diffusion coefficient of the product nuclide was observed to be identical to the default data. The results demonstrate the validity of the proposed method. The significance of the proposed numerical method will be particularly powerful in determining the diffusion coefficients of systems with extremely thin specimens, long periods of diffusion time, and parent nuclides with fast decay constants.
Representation of estuarine, coastal and marine biosphere systems within post-closure performance assessments supporting geological disposal of higher activity radioactive wastes in the UK
Mineralogical Magazine – November 2015
R. C. Walke, M. C. Thorne, J. T. Smith, and R. Kowe
Radioactive Waste Management Limited (RWM) is tasked with implementing geological disposal of the United Kingdom’s (UK) higher activity radioactive wastes. This paper describes how RWM’s biosphere modelling capability has been extended from a solely terrestrial model to allow potential contaminant releases to estuarine, coastal and marine systems around the UK to be represented. The new models aim to strike a balance between being as simple as can be justified, erring on the side of conservative estimates of potential doses, while also representing the features and processes required to reflect and distinguish UK coastal systems. Sediment dynamics (including meandering of estuaries and sediment accumulation) are explicitly represented in a simplified form that captures the accumulation and remobilization of radionuclides. Long-term transitions between biosphere systems (such as from a salt marsh to a terrestrial system) are outside the scope of the study. The models and supporting data draw on information about the UK that is representative of present-day conditions and represent potential exposures arising from both occupational and recreational habits.
An approach to modelling the impact of 14C release from reactor graphite in a geological disposal facility
Mineralogical Magazine – November 2015
Charalampos Doulgeris, Paul Humphreys, and Simon Rout
Carbon-14 (C-14) is a key radionuclide in the assessment of a geological disposal facility (GDF) for radioactive waste. In the UK a significant proportion of the national C-14 inventory is associated with reactor-core graphite generated by the decommissioning of the UK's Magnox and AGR reactors. There are a number of uncertainties associated with the fate and transport of C-14 in a post-closure disposal environment that need to be considered when calculating the radiological impacts of C-14-containing wastes. Some of these uncertainties are associated with the distribution of C-14-containing gaseous species such as 14CH4 and 14CO2 between the groundwater and gaseous release pathways. As part of the C14-BIG programme, a modelling framework has been developed to investigate these uncertainties. This framework consists of a biogeochemical near-field evolution model, incorporating a graphite carbon-14 release model, which interfaces with a geosphere/biosphere model. The model highlights the potential impact of the microbial reduction of 14CO2 to 14CH4, through the oxidation of H2, on C-14 transport. The modelling results could be used to inform the possible segregation of reactor graphite from other gasgenerating wastes.
Understanding the likelihood and consequences of post-closure criticality in a geological disposal facility
Mineralogical Magazine – November 2015
R.J. Winsley, T.D. Baldwin, T.W. Hicks, R.M. Mason, and P.N. Smith
A geological disposal facility (GDF) will include fissile materials that could, under certain conditions, lead to criticality. Demonstration of criticality safety therefore forms an important part of a GDF's safety case. Containment provided by the waste package will contribute to criticality safety during package transport and the GDF operational phase. The GDF multiple-barrier system will ensure that criticality is prevented for some time after facility closure. However, on longer post-closure timescales, conditions in the GDF will evolve and it is necessary to demonstrate: an understanding of the conditions under which criticality could occur; the likelihood of such conditions occurring; and the consequences of criticality should it occur. Work has addressed disposal of all of the UK's higher-activity wastes in three illustrative geologies. This paper, however, focuses on presenting results to support safe disposal of spent fuel, plutonium and highly-enriched uranium in higher-strength rock.
Representation of the biosphere in post-closure assessments for the UK geological disposal programme
Mineralogical Magazine – December 2012
R. Kowe and S. Norris
This paper gives an overview of the Nuclear Decommissioning Authority, Radioactive Waste Management Directorate approach to representing the biosphere in post-closure safety assessment studies. The assessments consider potential releases of radionuclides and chemically toxic substances from a geological disposal facility that may reach the biosphere by transport in groundwater and gas. It gives an outline of the key processes and understanding underpinning the representation of the biosphere and how the biosphere may evolve over the long timescales of relevance to post-closure safety. The current biosphere assessment approach and associated models are supported by research studies and collaboration that ensure they are consistent with international recommendations. Research studies are also commissioned to reduce uncertainty surrounding key contaminants and potential exposure pathways and to help ensure that the approach and models are adaptable and flexible enough to incorporate future developments, as the geological disposal programme moves towards site selection.
Radionuclide diffusion into undisturbed and altered crystalline rocks
Mineralogical Magazine – December 2012
V. Havlová, P. Večerník, J. Najser, K. Sosna, and K. Breiter
An extensive set of porosity, ε, effective diffusion coefficient, De, and hydraulic conductivity, K, data were obtained from 45 granitic samples from the Bohemian Massif, Czech Republic. The measured dataset can be used to define parameter ranges for data to be used in safety assessment calculations for a deep (>400 m) radioactive waste repository, even though the samples originated from shallower depths (<108 m). The dataset can also be used for other purposes, such as evaluating the migration of contaminants in granitic rock (e.g. from shallow intermediate-level radioactive waste repositories and chemical waste repositories). Sample relaxation and ageing processes should be taken into account in research otherwise migration parameters might be overestimated in comparisons between lab results and those determined in situ.
Sensitivity Analysis of Seals Permeability and Performance Assessment of Deep Borehole Disposal of Radioactive Waste
Sandia National Laboratories – 2013
Teklu Hadgu, Bill W. Arnold, Joon Hyub Lee, Geoff A. Freeze, Palmer Vaughn, Peter N. Swift, Cédric J. Sallaberry
The concept of disposal of high-level radioactive waste in deep boreholes, and probabilistic performance assessment (PA) of a generic disposal system are described. A series of preliminary PA simulations, conducted to evaluate the possible migration of radionuclides to an accessible environment, are presented. The PA simulations provide estimates of radionuclide releases and mean annual radiation doses. The simulations utilized vertical fluxes from a thermal-hydrology process model. Of particular interest to the present study is an analysis of the sensitivity of borehole and surrounding rock permeability values. The analysis provides a bounding exercise of the performance of a generic deep borehole disposal system.
Migration Behaviour of Strontium in Czech Bentonite Clay
Journal of Sustainable Development of Energy, Water and Environment Systems, Vol. 4 No. 3 – 2016
Lucie Baborová, Dušan Vopálka, Aleš Vetešník, and Eva Hofmanová, Czech Technical University in Prague
The study deals with sorption and diffusion behaviour of strontium in Czech bentonite B75. The study is a part of a research on reactive transport of radioactive contaminants in barrier materials of a deep geological repository of radioactive waste in the Czech Republic. Series of sorption and diffusion experiments with Sr and non-activated Ca bentonite B75 produced in the Czech Republic were performed in two background solutions (CaCl2 and NaCl). On the basis of sorption batch experiments the kinetics of strontium sorption on bentonite was assessed and the sorption isotherms for various experimental conditions were obtained. As a result of performed diffusion experiments the parameters of diffusion (i.e. effective diffusion coefficient De and apparent diffusion coefficient Da) were determined. The observed discrepancies between sorption characteristics obtained from the sorption and diffusion experiments are discussed.
A Prototype Performance Assessment Model for Generic Deep Borehole Repository for High-Level Nuclear Waste
WM2012 Conference – February 26 – March 1, 2012, Phoenix, Arizona, USA
Joon H. Lee, Bill W. Arnold, Peter N. Swift, Teklu Hadgu, Geoff Freeze, and Yifeng Wang, Sandia National Laboratories
A deep borehole repository is one of the four geologic disposal system options currently under study by the U.S. DOE to support the development of a long-term strategy for geologic disposal of commercial used nuclear fuel (UNF) and high-level radioactive waste (HLW). The immediate goal of the generic deep borehole repository study is to develop the necessary modeling tools to evaluate and improve the understanding of the repository system response and processes relevant to long-term disposal of UNF and HLW in a deep borehole. A prototype performance assessment model for a generic deep borehole repository has been developed using the approach for a mined geological repository. The preliminary results from the simplified deep borehole generic repository performance assessment indicate that soluble, non-sorbing (or weakly sorbing) fission product radionuclides, such as I-129, Se-79 and Cl-36, are the likely major dose contributors, and that the annual radiation doses to hypothetical future humans associated with those releases may be extremely small. While much work needs to be done to validate the model assumptions and parameters, these preliminary results highlight the importance of a robust seal design in assuring long-term isolation, and suggest that deep boreholes may be a viable alternative to mined repositories for disposal of both HLW and UNF.