@article{hamza_joslin_lawson_mcsweeney_liao_vivanco_diaconeasa_2024, title={Identifying and quantifying a complete set of full-power initiating events during early design stages of high-temperature gas-cooled reactors}, volume={242}, ISSN={["1879-0836"]}, url={https://doi.org/10.1016/j.ress.2023.109688}, DOI={10.1016/j.ress.2023.109688}, abstractNote={Identifying initiating events is the first step in building a probabilistic risk assessment model. The history of commercial nuclear power plant is primarily light-water reactors, hence, a comprehensive set of possible initiating events that covers most available light-water reactors is identified allowing for a frequentist approach to estimating their associated frequencies. However, other technologies of nuclear power plants do not share the same operating experience, hence, there are no comprehensive lists of initiating events for non-light-water reactors. This paper presents an approach that utilizes top-down deductive methodologies, master logic diagrams, and heat balance fault trees; the bottom-up inductive methodology of failure modes and effects analysis; and legacy and contemporary information to identify a complete list of initiating events for the Xe-100 high-temperature gas-cooled reactor (HTGR). Moreover, the paper presents the approach on how to estimate the frequencies using legacy sources along with deterministic analysis and fault trees. Furthermore, the paper presents an approach to estimate uncertainty parameters associated with each of these initiating events using constrained non-informative distributions to account for lack of operating experience. Finally, the paper presents the list of identified initiating events for the Xe-100 along with their frequencies and uncertainty parameters which serves, along with other contemporary sources, as another building block in having a comprehensive set of initiating events for HTGRs.}, journal={RELIABILITY ENGINEERING & SYSTEM SAFETY}, author={Hamza, Mostafa and Joslin, Nick and Lawson, Glen and McSweeney, Luke and Liao, Huafei and Vivanco, Alaina and Diaconeasa, Mihai A.}, year={2024}, month={Feb} }
 @article{lee_tayfur_hamza_alzahrani_diaconeasa_2023, title={A Limited-Scope Probabilistic Risk Assessment Study to Risk-Inform the Design of a Fuel Storage System for Spent Pebble-Filled Dry Casks}, url={https://doi.org/10.3390/eng4020094}, DOI={10.3390/eng4020094}, abstractNote={This limited-scope study demonstrates the application of probabilistic risk assessment (PRA) methodologies to a spent fuel storage system for spent pebble-filled dry cask with a focus only on the necessary PRA technical elements sufficient to risk-inform the spent fuel storage system design. A dropping canister scenario in a silo of the spent fuel storage system is analyzed through an initiating event (IE) identification from the Master Logic Diagram (MLD); event sequence analysis (ES) by establishing the event tree; data analysis (DA) for event sequence quantification (ESQ) with uncertainty quantification; mechanistic source term (MST) analysis by using ORIGEN; radiological consequence analysis (RC) by deploying MicroShield, and risk integration (RI) by showing the Frequency-Consequence (F-C) target curve in the emergency area boundary (EAB). Additionally, a sensitivity study is conducted using the ordinary least square (OLS) regression method to assess the impact of variables such as failed pebble numbers, their location in the canister, and building wall thickness. Furthermore, the release categories grouped from the end states in the event tree are verified as safety cases through the F-C curve. This study highlights the implementation of PRA elements in a logical and structured manner, using appropriate methodologies and computational tools, thereby showing how to risk-inform the design of a dry cask system for storing spent pebble-filled fuel.}, journal={Eng}, author={Lee, Joomyung and Tayfur, Havva and Hamza, Mostafa M. and Alzahrani, Yahya A. and Diaconeasa, Mihai A.}, year={2023}, month={Jun} }
 @article{earthperson_otani_nevius_prescott_diaconeasa_2023, title={A combined strategy for dynamic probabilistic risk assessment of fission battery designs using EMRALD and DEPM}, volume={160}, ISSN={0149-1970}, url={http://dx.doi.org/10.1016/j.pnucene.2023.104673}, DOI={10.1016/j.pnucene.2023.104673}, abstractNote={The notion of nuclear reactors with battery-like capabilities, called fission batteries, puts forth system requirements and design constraints that have so far been unseen in the nuclear power production industry. Such restrictions require fission batteries to be modular, integrated, autonomous, tamper-proof (i.e., resilient, fault-tolerant, all-weather, and safe), and affordable. With design requirements specifying no human intervention for operation, and minimal connectivity to remote monitoring networks, fission batteries are unique among existing nuclear power plants and emerging advanced reactor designs. Given these attributes, traditional probabilistic risk assessment (PRA) of fission batteries is expected to require dynamic methods to model advanced aspects, such as self-diagnosis, self-adjustment, and duration-prediction capabilities, as they are key ingredients for unattended operations. In addition, availability models need to integrate autonomous control, associated error-detection algorithms, and adversarial human actions. Currently, no existing framework demonstrably assesses these advanced attributes. This paper introduces and demonstrates an integrated framework for the dynamic modeling of fission battery designs. The proposed framework comprises a combined modeling strategy that uses the dual-graph error propagation methodology (DEPM) based on the continuous-time Markov chain (CTMC) models implemented in OpenPRA Error Propagation (OpenErrorPro) and the dynamic PRA tool, Event Modeling Risk Assessment using Linked Diagrams (EMRALD), based on discrete dynamic event trees (DDET). This combination overcomes some of the limitations of the tools when used independently. It enables detailed dynamic analysis to produce time explicit results to support the development of fission battery traditional PRA models. To evaluate the utility of this novel approach, a demonstration case is shown that models the hypothesized response of a fission battery design to an external fire event. DEPM CTMCs and alternative failure approaches are coupled with EMRALD to characterize and quantify the likelihood of the event sequences. The results show that the combined framework effectively captures the dynamic aspects of fission battery design in terms of the timing and realism of modeled events. Given the complexity of the failure scenarios, we believe that EMRALD and DEPM are necessary and complementary when the need for high-resolution analysis offsets the challenges of detailed modeling.}, journal={Progress in Nuclear Energy}, publisher={Elsevier BV}, author={Earthperson, Arjun and Otani, Courtney M. and Nevius, Daniel and Prescott, Steven R. and Diaconeasa, Mihai A.}, year={2023}, month={Jun}, pages={104673} }
 @article{earthperson_diaconeasa_2023, title={Dynamic Probabilistic Risk Assessment of Commercial-Off-The-Shelf Drones in Nuclear-Contaminated Search and Rescue Missions}, url={https://doi.org/10.20944/preprints202307.0395.v1}, DOI={10.20944/preprints202307.0395.v1}, abstractNote={This paper presents a limited scope dynamic probabilistic risk assessment (D-PRA) on the survivability of commercial of the shelf (COTS) drones tasked with surveilling areas with varying radiation levels after a nuclear accident. The D-PRA is based on a discrete-dynamic event tree (D-DET) approach, which couples with the OpenEPL error propagation framework to model sequences leading to Loss of Mission (LOM) scenarios due to component failures in the drone’s navigation system. Radiation effects are simulated by calculating the total ionizing dose (TID) against the permissible limit per component, and errors are propagated within the electronic hardware and software blocks to quantify navigation system availability per radiation zone. The proposed methods are integrated into the traditional event tree/fault tree approach and the most vulnerable components are radiation-hardened (RAD-HARD) to the extent specified by a predefined mission success criterion. The results demonstrate the usefulness of the proposed approach in performing trade studies for incorporating COTS components into RAD-HARD drone designs.}, author={Earthperson, Arjun and Diaconeasa, Mihai A.}, year={2023}, month={Jul} }
 @article{earthperson_diaconeasa_2023, title={Integrating Commercial-Off-The-Shelf Components into Radiation-Hardened Drone Designs for Nuclear-Contaminated Search and Rescue Missions}, volume={7}, ISSN={["2504-446X"]}, url={https://doi.org/10.3390/drones7080528}, DOI={10.3390/drones7080528}, abstractNote={This paper conducts a focused probabilistic risk assessment (PRA) on the reliability of commercial off-the-shelf (COTS) drones deployed for surveillance in areas with diverse radiation levels following a nuclear accident. The study employs the event tree/fault tree digraph approach, integrated with the dual-graph error propagation method (DEPM), to model sequences that could lead to loss of mission (LOM) scenarios due to combined hardware–software failures in the drone’s navigation system. The impact of radiation is simulated by a comparison of the total ionizing dose (TID) with the acceptable limit for each component. Errors are then propagated within the electronic hardware and software blocks to determine the navigation system’s reliability in different radiation zones. If the system is deemed unreliable, a strategy is suggested to identify the minimum radiation-hardening requirement for its subcomponents by reverse-engineering from the desired mission success criteria. The findings of this study can aid in the integration of COTS components into radiation-hardened (RAD-HARD) designs, optimizing the balance between cost, performance, and reliability in drone systems for nuclear-contaminated search and rescue missions.}, number={8}, journal={DRONES}, author={Earthperson, Arjun and Diaconeasa, Mihai A.}, year={2023}, month={Aug} }
 @article{hamza_diaconeasa_2023, title={Investigating the applicability of human reliability analysis methods during early design stages of non-light-water nuclear power plants}, volume={161}, ISSN={["1878-4224"]}, url={https://doi.org/10.1016/j.pnucene.2023.104716}, DOI={10.1016/j.pnucene.2023.104716}, abstractNote={Human interventions are an integral part of any system, whether through design, operation, maintenance, or upgrading. Moreover, although the reliance on human intervention in safety-related actions in advanced reactors (e.g., Generation IV) is expected to be reduced or completely replaced by automated actions, nuclear power plants (NPP) require human actions throughout their lifecycle from design, construction, operation, and decommissioning. Hence, the impacts of all operator actions are required to be captured and incorporated in the probabilistic risk assessment (PRA) of the modeled plant. Furthermore, a risk-informed and performance-based design and licensing approach expects that a PRA model, including human reliability analysis (HRA), is developed starting from the early design stages and used to inform all design iterations. However, due to the lack of details during the early design stages, HRA is often postponed until the design is mature enough. Conducting HRA in the final design stages, though adequate in capturing pre-, at-, and post-initiators, comes short of informing the design itself in the iterative design lifecycle. Moreover, due to most HRA methodologies being developed utilizing mostly the operating experience of existing light water reactors, limited guidance is available to the applicability of different HRA methodologies during the early stages of the design. Limited guidance is available, as well, on how to utilize the results of HRA in informing the design of later iterations. Hence, this study presents an investigation of the applicability of different HRA methodologies during the early stages of the design. The structure of a representative set of nine HRA methodologies is assessed against the available operating and emergency procedures within different design stages. Furthermore, these different HRA methodologies are assessed based on the availability of guidance on how to use their results to risk-inform the design in an iterative design process. Finally, the applicability of Open Preliminary Human Importance (OpenPHI) methodology, introduced specifically to implement HRA during early design stages, is assessed during the early stages of the design and compared against other methodologies.}, journal={PROGRESS IN NUCLEAR ENERGY}, author={Hamza, Mostafa and Diaconeasa, Mihai A.}, year={2023}, month={Jul} }
 @article{farag_alzahrani_diaconeasa_2023, title={Pool inlet LOCA safety analysis in support of the emergency core spray system success criteria development of the PULSTAR research reactor}, volume={403}, ISSN={["1872-759X"]}, url={https://doi.org/10.1016/j.nucengdes.2023.112163}, DOI={10.1016/j.nucengdes.2023.112163}, abstractNote={The PULSTAR pool-type research reactor has been operating at power levels up to 1 MWth since initial criticality in 1972 on the North Carolina State University (NCSU) campus. At the current power level, there is no need for an emergency core cooling system to provide additional cooling during abnormal conditions since, at this power level, the peak cladding temperature (PCT) cannot reach the maximum allowable temperature. The range of experiments possible could be extended if the reactor is to be licensed by the U.S. Nuclear Regulatory Commission (NRC) to run up to higher power levels. However, the maximum allowable PCT at higher power levels could be exceeded during abnormal conditions. In this study, a best estimate transient simulation model is used to inform the design of an emergency core spray system to the PULSTAR research reactor. We provide the analysis results of the most limiting scenario of a pool inlet large break loss of coolant accident (LOCA) while operating at higher power levels. Currently, NCSU’s research reactor program is developing a plan to increase the operating power to 2 MWth, thus most of the analysis performed in this paper is prepared at 2 MWth. In addition, a parametric study was carried out to obtain the maximum achievable operating power by having the emergency core spray system installed with the current coolant system arrangement.}, journal={NUCLEAR ENGINEERING AND DESIGN}, author={Farag, Asmaa S. and Alzahrani, Yahya A. and Diaconeasa, Mihai A.}, year={2023}, month={Mar} }
 @article{farag_alzahrani_diaconeasa_2023, title={Pool inlet LOCA safety analysis in support of the emergency core spray system success criteria development of the PULSTAR research reactor (vol 403, 112163, 2023)}, volume={408}, ISSN={["1872-759X"]}, DOI={10.1016/j.nucengdes.2023.112342}, journal={NUCLEAR ENGINEERING AND DESIGN}, author={Farag, Asmaa S. and Alzahrani, Yahya A. and Diaconeasa, Mihai A.}, year={2023}, month={Jul} }
 @book{bao_zhang_youngblood iii_shothill_pandit_chen_park_diaconeasa_dinh_lawrence_2023, title={Risk Analysis of Various Design Architectures for High Safety-significant Safety-related Digital Instrumentation and Control Systems of Nuclear Power Plants during Accident Scenarios}, url={https://www.osti.gov/biblio/1986002}, author={Bao, Han  ; and Zhang, Sai  ; and Youngblood III, Robert Walker  ; and Shothill, Tate ; and Pandit, Priyanka ; and Chen, Edward ; and Park, Jooyoung  ; and Diaconeasa, Mihai ; and Dinh, Nam ; and Lawrence, Svetlana}, year={2023}, month={Dec} }
 @article{hamza_diaconeasa_2022, title={A framework to implement human reliability analysis during early design stages of advanced reactors}, volume={146}, ISSN={["1878-4224"]}, url={https://doi.org/10.1016/j.pnucene.2022.104171}, DOI={10.1016/j.pnucene.2022.104171}, abstractNote={Nuclear power plants require human actions throughout their lifecycle from design, construction, operation, and decommissioning. However, for advanced reactors (e.g., Generation IV), the reliance on human intervention in safety-related actions is expected to be reduced or completely replaced by automated actions. The Probabilistic Risk Assessment (PRA) Standard for Advanced Non-LWR Nuclear Power Plants requires that the impacts of all operator actions are captured and incorporated in the risk of the modeled plant. Moreover, the Modernization of Technical Requirements for Licensing Advanced Reactors requires human reliability analysis (HRA) to be included throughout all design and PRA development stages. However, due to the lack of details during the early design stages, HRA is often postponed until the design is mature enough. Conducting HRA in later design stages, though it may be adequate in capturing pre-, at-, and post-initiators comes short of informing the design itself in the iterative design lifecycle. Hence, this paper presents a framework to include HRA during the design's early stages, pre-conceptual or conceptual. The proposed framework provides a process for the removal of operator actions that do not contribute to the risk and the identification of all key operator actions that are critical to the safety of the design. The results of this framework are then used to inform the design of those safety-related operator actions to update the design further. Then, using information from the updated design, this framework can be reapplied to investigate the impact of the design update on human reliability. The PRA model of the X-energy's pre-conceptual Xe-100 high-temperature gas-cooled pebble-bed reactor (HTGR-PB) design is used to demonstrate the approach. In the pre-conceptual Xe-100 PRA model, also called Phase 0 PRA model, human actions were considered an integral part of analyzing the plant response to different initiating events. Hence, in this paper, all possible human actions in the Xe-100 PRA model are identified, analyzed, and removed to emulate a design relying only on the available automated control systems. The preliminary results of this assessment show how safe the Xe-100 design is even without crediting any human actions. The results also list necessary sequences in which operator actions are critical to the risk profile of the design.}, journal={PROGRESS IN NUCLEAR ENERGY}, publisher={Elsevier BV}, author={Hamza, Mostafa and Diaconeasa, Mihai A.}, year={2022}, month={Apr} }
 @article{grimmeisen_karimov_diaconeasa_morozov_2022, title={Demonstration of a Limited Scope Probabilistic Risk Assessment for Autonomous Warehouse Robots With OpenPRA}, volume={13}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85124509982&partnerID=MN8TOARS}, DOI={10.1115/imece2021-69998}, abstractNote={
 Probabilistic Risk Assessment (PRA) is an indispensable technology to evaluate the risk, dependability, and resilience characteristics of safety-critical systems. Therefore, PRA uses widely adopted methods, such as classical event trees, fault trees, Markov chains, Bayesian networks, and their numerous combinations. To analyze challenging failure scenarios of modern, intelligent, autonomous, and highly dynamic Cyber-Physical Systems (CPS), the integration of multiple PRA methods is needed. This paper presents a PRA approach based on classical Event Tree Analysis (ETA) and Fault Tree Analysis (FTA) and provides the technical description of a new open-source software platform called OpenPRA. Besides, this paper describes a representative case study from the autonomous system domain, focusing on autonomous warehouse robots.}, journal={Volume 13: Safety Engineering, Risk, and Reliability Analysis; Research Posters}, publisher={American Society of Mechanical Engineers}, author={Grimmeisen, Philipp and Karimov, Artur and Diaconeasa, Mihai A. and Morozov, Andrey}, year={2022}, month={Jan} }
 @article{polat_diaconeasa_2022, title={On the Modeling of Wildfires-Induced Release and Atmospheric Dispersion in Radioactively Contaminated Regions}, volume={13}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85124550982&partnerID=MN8TOARS}, DOI={10.1115/imece2021-71460}, abstractNote={
 Nuclear energy is one of the most efficient types of electricity production. However, it is one of the biggest fears of people due to the potential radiation effects on human health. Despite the major developments in the nuclear sector, some gaps need to be studied for the higher safety scrutiny of nuclear power plants (NPPs). Besides technical advances for the safer management of an NPP, another important part is having a well-constructed and planned probabilistic risk assessment and management. Realistic probabilistic risk assessment and management provide proper emergency response in case of an accident or hazardous situation to human health. On the other hand, aside from the radiation emitted directly from radioactive sources inside the NPP, there may be indirect radiation emission from dispersions outside the plant’s protected area. For example, we can look at forest fires occurring in radioactively contaminated areas surrounding NPPs that suffered accidents with releases, such as Chernobyl or Fukushima Daiichi. Radioactive particles produced by burning contaminated forests could spread in the air and threaten public health. It has already been observed that fires in forests around Chernobyl can increase the level of radiation in the air. Such events have the possibility to occur in all areas where nuclear facilities are located. The forests contaminated after the Fukushima Daiichi NPP accident, resemble the ones at Chernobyl. This study aims to develop the knowledge for an early sensing and emergency response by doing an atmospheric dispersion modeling and supporting a probabilistic risk assessment for a wildfire scenario in radioactively contaminated areas, such as Chernobyl and Fukushima Daiichi. Also, this study provides a pathway to assessing the risk of nuclear contamination caused by wildfires around nuclear facilities.}, journal={Volume 13: Safety Engineering, Risk, and Reliability Analysis; Research Posters}, publisher={American Society of Mechanical Engineers}, author={Polat, Damla and Diaconeasa, Mihai A.}, year={2022}, month={Jan} }
 @article{polat_diaconeasa_2022, title={On the Use of Probabilistic Risk Assessment for the Protection of Small Modular Reactors Against Terrorist Attacks}, volume={13}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85124539594&partnerID=MN8TOARS}, DOI={10.1115/imece2021-71504}, abstractNote={
 Safety and security are two of the most important requirements of the nuclear industry. In the event of a potential problem, the consequences can have serious implications for the public and the environment. Measures should be taken against various hazards and threats by analyzing possible realistic scenarios. Therefore, probabilistic risk assessment is one of the necessary technologies to achieving safe and secure nuclear facilities. In the study, a limited scope probabilistic risk assessment was made for a possible terrorist attack against a generic small modular reactor (SMR). A possible attack threat was selected to develop scenarios by following a probabilistic risk assessment approach.
 In the scenarios created, terrorists have to pass all physical barriers that security guards protect. Thus, the decisions and actions of the security guards directly affect the result of the attack. To analyze these events, a human reliability assessment (HRA) was employed. In the first study, each security guard’s decision-making process was analyzed using the Standardized Plant Analysis Risk Human Reliability Assessment (SPAR-H) method. The purpose of its use in this study is to verify the SPAR-H method’s applicability for security applications.
 In this paper, we give the likelihoods of each security guard making a decision and taking action to prevent terrorists from passing obtained using the SPAR-H method. Besides, event tree and fault tree analyses were performed using the SAPHIRE PRA software.
 Finally, since the current HRA methods were designed for control room operators, we introduce a new model-based HRA methodology applicable for security guards to be used in physical security PRAs.}, journal={Volume 13: Safety Engineering, Risk, and Reliability Analysis; Research Posters}, publisher={American Society of Mechanical Engineers}, author={Polat, Burak and Diaconeasa, Mihai A.}, year={2022}, month={Jan} }
 @article{lee_diaconeasa_2022, title={Preliminary Siting, Operations, and Transportation Considerations for Licensing Fission Batteries in the United States}, url={https://doi.org/10.3390/eng3030027}, DOI={10.3390/eng3030027}, abstractNote={Nuclear energy is currently in the spotlight as a future energy source all over the world amid the global warming crisis. In the current state of miniaturization, through the development of advanced reactors, such as small modular reactors (SMRs) and micro-reactors, a fission battery is inspired by the idea that nuclear energy can be used by ordinary people using the “plug-and-play” concept, such as chemical batteries. As for design requirements, fission batteries must be economical, standardized, installed, unattended, and reliable. Meanwhile, the commercialization of reactors is regulated by national bodies, such as the United States (U.S.) Nuclear Regulatory Commission (NRC). At an international level, the International Atomic Energy Agency (IAEA) oversees the safe and peaceful use of nuclear power. However, regulations currently face a significant gap in terms of their applicability to advanced non-light water reactors (non-LWRs). Therefore, this study investigates the regulatory gaps in the licensing of fission batteries concerning safety in terms of siting, autonomous operation, and transportation, and suggests response strategies to supplement them. To figure out the applicability of the current licensing framework to fission batteries, we reviewed the U.S. NRC Title 10, Code of Federal Regulations (CFR), and IAEA INSAG-12. To address siting issues, we explored the non-power reactor (NPR) approach for site restrictions and the permit-by-rule (PBR) approach for excessive time burdens. In addition, we discussed how the development of an advanced human-system interface augmented with artificial intelligence and monitored by personnel for fission batteries may enable successful exemptions from the current regulatory operation staffing requirements. Finally, we discovered that no transportation regulatory challenge exists.}, journal={Eng}, author={Lee, DaeHo and Diaconeasa, Mihai A.}, year={2022}, month={Sep} }
 @inproceedings{yang hui otani_christian_prescott_diaconeasa_earthperson_2022, title={Probabilistic Methods for Cyclical and Coupled Systems with Changing Failure Rates}, url={https://www.osti.gov/biblio/1885929}, author={Yang Hui Otani, Courtney Mariko  ; and Christian, Robby ; and Prescott, Steven R  ; and Diaconeasa, Mihai  ; and Earthperson, Arjun}, year={2022}, month={Apr} }
 @article{aras_diaconeasa_2021, title={A Critical Look at the Need for Performing Multi-Hazard Probabilistic Risk Assessment for Nuclear Power Plants}, volume={2}, url={https://doi.org/10.3390/eng2040028}, DOI={10.3390/eng2040028}, abstractNote={Probabilistic Risk Assessment (PRA) is one of the technologies that is used to inform the design, licensing, operation, and maintenance activities of nuclear power plants (NPPs). A PRA can be performed by considering the single hazard (e.g., earthquake, flood, high wind, landslide) or by considering multi-hazards (e.g., earthquake and tsunami, high wind and internal fire). Single hazard PRA was thought sufficient to cover the analysis of a severe accident until the Fukushima Daiichi NPP accident in 2011. Since then, efforts were made to consider multi-hazards as well; thus, multi-hazard PRAs are starting to be seen as being indispensable for NPPs. In addition to the changing frequency of global and local natural hazards, other reasons to be highlighted are that the number and diversity of NPPs will probably increase. Moreover, advanced reactors are close to becoming a reality by designing them with passive safety systems, smaller, standardized, and even transportable to make them cheaper across the design, licensing construction, and operation stages. Thus, multi-hazards should be addressed in any future full-scope PRA. Although we found a few studies discussing multi-hazards, a general framework for multi-hazard PRA is still missing. In this paper, we argue that the starting point for any multi-hazard PRA general framework should be the Advanced Non-LWR Licensing Basis Event Selection (LBE) Approach and Probabilistic Risk Assessment Standard for Non-Light Water Reactor (non-LWR) Nuclear Power Plants. For Probabilistic Risk Assessment (PRA), history has shown us the path forward before, with Three Mile Accident being seen as one milestone to understand the necessity of PRA. The Fukushima Daiichi NPP Accident is another milestone in the development of PRA, showing the need for performing multi-hazard PRA for the current and future NPPs.}, number={4}, journal={Eng}, publisher={MDPI AG}, author={Aras, Egemen M. and Diaconeasa, Mihai A.}, year={2021}, month={Oct}, pages={454–467} }
 @article{morozov_diaconeasa_steurer_2021, title={A Hybrid Methodology for Model-Based Probabilistic Resilience Evaluation of Dynamic Systems}, volume={14}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85101290861&partnerID=MN8TOARS}, DOI={10.1115/imece2020-23789}, abstractNote={
 Advanced classical Probabilistic Risk Assessment (PRA) effectively combines various methods for quantitative risk evaluation, such as event trees, fault trees, and Bayesian networks. PRA methods and tools provide the means for the qualitative reliability evaluation (e.g., cut sets) and the computation of quantitative reliability metrics (e.g., end states probabilities). Modern safety-critical systems from various industrial domains tend toward a high level of autonomy and demand not only reliability but also resilience, the ability to recover from degraded or failed states. The numerical resilience analysis of such dynamic systems requires more flexible methods. These methods shall enable the analysis of the systems with sophisticated software parts and dynamic feedback loops. A suitable candidate is the Dual-graph Error Propagation Model (DEPM) that can capture nontrivial failure scenarios and dynamic fault-tolerance mechanisms. The DEPM exploits the method for the automatic generation of Markov chain models and the application of probabilistic model checking techniques. Moreover, the DEPM enables the analysis of highly-customizable system resilience metrics, e.g., “the probability of system recovery to a particular state after a specified system failure during a defined time interval.” In this paper, we show how DEPM-based resilience analysis can be integrated with the general PRA methodology for resilience evaluations. The proposed methodology is demonstrated on a safety-critical autonomous UAV system.}, journal={Volume 14: Safety Engineering, Risk, and Reliability Analysis}, publisher={American Society of Mechanical Engineers}, author={Morozov, Andrey and Diaconeasa, Mihai A. and Steurer, Mikael}, year={2021}, month={Feb} }
 @inproceedings{pandit_earthperson_tezbasaran_diaconeasa_2021, title={A Quantitative Approach to Assess the Likelihood of Supply Chain Shortages}, volume={13}, url={http://dx.doi.org/10.1115/IMECE2021-73696}, DOI={10.1115/imece2021-73696}, abstractNote={
 We define supply chains (SCs) as sequences of processes that link the demand and supply of goods or services within a network. SCs are prone to shortages in delivering their output goals due to several factors such as personnel undersupply, inefficient processes, policy failure, equipment malfunction, natural hazards, pandemic outbreaks, power outages, or economic crises. Recent notable supply-chain failures include the 2021 Texas power crisis, personal protection equipment shortages during the COVID-19 pandemic, and regional or global food chain shortages. The consequences of such shortages can range from negligible to devastating. The Texas power crisis resulted in the death of 70 people and left approximately 4.5 billion homes and businesses without power for multiple days.
 In this paper, we presented a methodology to quantify the failure probability of the throughput of a supply chain. We divided the methodology into two major categories of steps. In the first step, we converted the given or assumed supply chain data into fault trees and quantify them. In the second step, we iterated the quantification of the fault tree to build a supply chain shortage risk profile. We introduced the notion of success criteria for the output from a facility, based on which we included or excluded the facility for quantification.
 With the inclusion of relevant field data, we believe that our methodology can enable the stakeholders in the supply-chain decision-making process to detect vulnerable facilities and risk-inform prevention and mitigation actions. Applications for this methodology can include construction, inventory stocking, assessing manufacturing quantities, policy changes, personnel allocation, and financial investment for critical industries such as nuclear, pharmaceutical, aviation, etc.}, booktitle={Volume 13: Safety Engineering, Risk, and Reliability Analysis; Research Posters}, publisher={American Society of Mechanical Engineers}, author={Pandit, Priyanka and Earthperson, Arjun and Tezbasaran, Alp and Diaconeasa, Mihai A.}, year={2021}, month={Nov} }
 @inproceedings{pandit_tezbasaran_earthperson_diaconeasa_2021, title={Evaluating the Implementation of Distributed Ledger Technology for the Licensing and Regulation of Nuclear Power Plants}, volume={8B-2021}, url={http://dx.doi.org/10.1115/IMECE2021-71730}, DOI={10.1115/imece2021-71730}, abstractNote={
 The approval process from the U.S. Nuclear Regulatory Commission (NRC) for nuclear power plants is sequential. It involves several government bodies such as the Advisory Committee on Reactor Safeguards (ACRS), public meetings, and hearings. If the submissions made to the NRC do not contain enough information to meet the regulation requirements, the NRC issues a Request for Additional Information (RAI). Thus, the licensee has to go through a paperwork-intensive process that involves multiple regulatory agencies for the various licensing requirements. Moreover, sending applications to the NRC is limited to using an electronic submission generation tool called the Packing Slip Wizard (PSW).
 This paper presents a methodology to implement Distributed Ledger Technology (DLT) to address the need for a real-time, digitized documentation platform in the nuclear power industry’s licensing and regulation process.
 The evaluation of DLT’s implementation resulted in the formulation of a methodology to accept submissions from an applicant on a web application and storing the received data on a distributed ledger. The presented method offers a real-time submission of the available information of an application. It facilitates the NRC with a real-time feedback capability expediting the review process. RAI’s can be reduced in number by ensuring that the NRC’s information requirements are defined as smart contracts.}, booktitle={Volume 8B: Energy}, publisher={American Society of Mechanical Engineers}, author={Pandit, Priyanka and Tezbasaran, Alp and Earthperson, Arjun and Diaconeasa, Mihai A.}, year={2021}, month={Nov} }
 @article{rabiei_huang_chien_earthperson_diaconeasa_woo_iyer_white_mosleh_2021, title={Method and software platform for electronic COTS parts reliability estimation in space applications}, volume={232}, ISSN={1748-006X 1748-0078}, url={http://dx.doi.org/10.1177/1748006X21998231}, DOI={10.1177/1748006X21998231}, abstractNote={Adoption of electronic Commercial-Off-The-Shelf (COTS) parts in various industrial products is rapidly increasing due to the accessibility and appealing lower cost of these commodities. Depending on the type of application, having an accurate understanding of the COTS failure information can be crucial to ensure the reliability and safety of the final products. On the other hand, frequent large-scale testing is often cost prohibitive and time consuming for emerging technologies, especially in the consumer electronics sector where minimizing time-to-market and cost is critical. This paper presents a comprehensive Bayesian approach and software platform (named COTS Reliability Expert System), that integrates multiple pieces of heterogeneous information about the failure rate of COTS parts. The ultimate goal is to reduce dependency on testing for reliability analysis and yet to obtain a more accurate “order of magnitude” estimate of the failure rate through an efficient process. The method provides a foundation for incorporating manufacturers reliability data, estimates based on underlying physics-of-failure mechanisms and circuit simulations, partially relevant life test data of similar (but not necessarily identical) parts, and expert opinions on the manufacturing process of the COTS part of interest. The developed expert system uses Bayesian estimation to integrate all these types of evidence. The methodology is demonstrated in estimating the failure rate of a static random-access memory (SRAM) part.}, number={5}, journal={Proceedings of the Institution of Mechanical Engineers, Part O: Journal of Risk and Reliability}, publisher={SAGE Publications}, author={Rabiei, E. and Huang, L. and Chien, H. and Earthperson, Arjun and Diaconeasa, M.A. and Woo, J. and Iyer, S. and White, M. and Mosleh, A.}, year={2021}, month={Mar}, pages={744–760} }
 @misc{earthperson_diaconeasa_2021, title={Verification Study of the Nuclear PRA for the Mars 2020 Mission Following Accidental Orbital Re-Entry}, volume={13}, url={http://dx.doi.org/10.1115/IMECE2021-71359}, DOI={10.1115/imece2021-71359}, abstractNote={
 Today, Probabilistic Risk Assessment (PRA) plays a vital role in assuring mission success for robotic and crewed missions alike. Current-day PRA techniques integrate multimodal, often black-box analyses to build comprehensive risk profiles. This paper describes a review and verification study of the “Nuclear Risk Assessment for the Mars 2020 Mission Environmental Impact Statement” (N-PRA)[1]. Sandia National Labs conducted the N-PRA for NASA’s Jet Propulsion Laboratory (JPL). More specifically, we have verified the source term calculations associated with the release of radionuclides from a Multi-Mission Radiothermoelectic Generator (MMRTG) power source for a limited set of accident scenarios in the case of an accidental re-entry into Earth Orbit with an Earth impacting trajectory.
 We achieve this by using analytical methods[2] historically implemented for the Cassini Mission PRA[3] for a failed planetary swingby gravity-assist. Our results are within 28% to 56% of the referenced study. Limitations in our methodology are attributed to a lack of modern simulation-based tools and deterministic methods for modeling complex physical phenomena. The results are interpreted and compared with the values presented by the initial authors, along with comments for improving our current methodology.}, journal={Volume 13: Safety Engineering, Risk, and Reliability Analysis; Research Posters}, publisher={American Society of Mechanical Engineers}, author={Earthperson, Arjun and Diaconeasa, Mihai A.}, year={2021}, month={Nov} }
 @article{wu_wang_diaconeasa_mosleh_wang_2020, title={A Comparative Assessment of Collision Risk of Manned and Unmanned Vessels}, volume={8}, ISSN={["2077-1312"]}, url={https://doi.org/10.3390/jmse8110852}, DOI={10.3390/jmse8110852}, abstractNote={It is expected that the prototypes of unmanned merchant ships will be deployed in the next few years. However, there is no specific research on whether the introduction of unmanned ships will reduce the risk of ship collision accidents in which communication between vessels is critical. This work constitutes an attempt to bridge the gap identified above by applying the Hybrid Causal Logic (HCL) methodology to model general-level collision scenarios of unmanned ships. The HCL methodology has been selected for its proven applicability to risk assessments, even when empirical data may be insufficient. Collision scenarios involving unmanned ships have been created in which manned ships of the conventional collision scenario HCL model are replaced with unmanned ships. Then, collision scenarios capturing the interactions between a manned ship and an unmanned ship were modeled. By comparing the qualitative and quantitative results of the different scenarios, we can see that the introduction of unmanned ships may effectively reduce the occurrence of ship collision accidents.}, number={11}, journal={JOURNAL OF MARINE SCIENCE AND ENGINEERING}, publisher={MDPI AG}, author={Wu, Qing and Wang, Tengfei and Diaconeasa, Mihai A. and Mosleh, Ali and Wang, Yang}, year={2020}, month={Nov} }
 @article{chalgham_diaconeasa_wu_mosleh_2020, title={A Dynamic Pipeline Network Health Assessment Software Platform for Optimal Risk-Based Prioritization of Inspection, Structural Health Monitoring, and Proactive Management}, volume={13}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85078700418&partnerID=MN8TOARS}, DOI={10.1115/imece2019-11806}, abstractNote={
 The Pipeline Health Monitoring and Management web application is a risk-based pipeline integrity management support tool to support pipeline operators in decision-making and planning activities. The platform design is supported by a multi-disciplinary science and engineering approach for a comprehensive, state-of-the-art solution. The goal of the software platform is to integrate the data, methods, and technologies into a dynamic pipeline heath monitoring system supported by multiple probabilistic predictive models such as dynamic hybrid causal logic, corrosion prognosis, and sensor placement optimization models. This total system health management support tool provides online or offline updates on the reliability state of various segments of the pipeline system, and dynamically updates the recommendations on when and where to take mitigating actions, e.g., increase or decrease inspection frequency. The pipeline health monitoring system software platform under development provides the ability for (a) Integrity assessment based on comprehensive range of evidence from sensing, inspection, and real-time monitoring in addition to probabilistic integration of mechanistic models and data on failure mechanisms relating to various causal factors (e.g., uniform corrosion, pitting corrosion, etc.) for assessment of the pipe segment health (remaining life); (b) Dynamic pipeline network probabilistic health assessment model software for optimal risk-based prioritization of inspection and proactive management, and (c) Geographical mapping capabilities that will augment the interaction of the pipeline operators with the pipeline system such as viewing pipeline/sensor locations, and adding new pipelines if desired. The selected computational foundation for the assessment is the hybrid causal logic engine with a wide range of capabilities in terms of system model building and probabilistic analysis of various types of evidence for assessment of model parameters. On this foundation we are adding capabilities to integrate predictive corrosion models, sensor placement optimization, and computational modules to perform pipeline health assessment, and develop inspection and maintenance strategies. The resulting software will be deployed as a control room health dashboard and hand-held web-based field inspection support tool.}, journal={Volume 13: Safety Engineering, Risk, and Reliability Analysis}, publisher={American Society of Mechanical Engineers}, author={Chalgham, Wadie and Diaconeasa, Mihai and Wu, Keo-Yuan and Mosleh, Ali}, year={2020}, month={Jan} }
 @article{chalgham_diaconeasa_gottumukkala_seibi_2020, title={A Numerical and Experimental Study Supporting a Methodology for Live Monitoring, Leak Detection, and Automatic Response in Water Pipelines}, volume={13}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85078704982&partnerID=MN8TOARS}, DOI={10.1115/imece2019-11861}, abstractNote={
 This paper describes a numerical analysis supported by small scale experiments for demonstrating a monitoring and leak detection methodology. This study can be used to build a full-scale water pipeline monitoring and response system. The monitoring system is able to monitor the pipeline health and respond to hazard conditions through the use of multiple sensors driven by a hybrid rule-based and statistical monitoring control strategy. The system is programmed to automatically shut off its pump in the event of out-of-bounds/out-of-statistical control conditions detected by its sensors. In addition, this paper presents a numerical simulation analysis approach supported by an experiment that aims at finding a relationship between the location and size of an induced leak and the reported sensor data. The obtained results are used to inform a probabilistic model that can be used to estimate the leak location and size based on flow rate variations. The proposed project will enhance remote pipeline monitoring and structural safety by offering real-time data and automatic emergency response capabilities.}, journal={Volume 13: Safety Engineering, Risk, and Reliability Analysis}, publisher={American Society of Mechanical Engineers}, author={Chalgham, Wadie and Diaconeasa, Mihai and Gottumukkala, Raju and Seibi, Abdennour}, year={2020}, month={Jan} }
 @article{chalgham_diaconeasa_elgazzar_seibi_2020, title={A Smart Pipeline Monitoring and Emergency Response System Using Web Services}, volume={13}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85078707186&partnerID=MN8TOARS}, DOI={10.1115/imece2019-11825}, abstractNote={
 The Smart Pipeline Monitoring System introduced in this paper demonstrates a proof-of-concept for replicating a full-scale water pipeline system that is able to monitor the pipeline health and respond to hazard conditions through the use of multiple sensors and a statistical monitoring control strategy. The system aims at mitigating the effects of common sources of damage that occur in pipelines, such as leaks and overheating, by offering real time data visualization and autonomous actions in case of emergencies. The data visualization is provided by a desktop user interface and a mobile application. In the case of a detected anomaly, described by out-of-bounds/out-of-statistical control conditions detected by the sensors, the system is programmed to shut off its pump and alert the supervisors by SMS instantly. The proposed monitoring system will enhance remote pipeline monitoring and structural safety by offering real-time data and automatic emergency response capabilities. Our experimental results and prototype implementation show that the proposed system effectively detects anomaly conditions under various realistic scenarios and takes necessary safety measures to prevent further damages.}, journal={Volume 13: Safety Engineering, Risk, and Reliability Analysis}, publisher={American Society of Mechanical Engineers}, author={Chalgham, Wadie and Diaconeasa, Mihai and Elgazzar, Khalid and Seibi, Abdennour}, year={2020}, month={Jan} }
 @article{diaconeasa_mosleh_morozov_tai_2020, title={Model-Based Resilience Assessment Framework for Autonomous Systems}, volume={13}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85078694886&partnerID=MN8TOARS}, DOI={10.1115/imece2019-12288}, abstractNote={
 While automation technologies advance faster than ever, gaps of resilience capabilities between autonomous and human-operated systems have not yet been identified and addressed appropriately. To date, there exists no generic framework for resilience assessment that is applicable to a broad spectrum of domains or able to take into account the impacts on mission-scenario-level resilience from system-specific attributes. In the proposed framework, resilience is meant to describe the ability of a system, in an open range of adverse scenarios, to maintain normal operating conditions or to recover from degraded or failed states in order to provide anticipated functions or services to achieve mission success. The term resilience is introduced in relation with classical terms such as fault, error, failure, fault-tolerance, reliability, and risk. The proposed model-based resilience assessment framework is based on a resilience ontology that enables the use of system models into reliability and risk models for transparent, persistent, and up-to-date modeling and quantification. A SysML profile and associated OWL ontology are defined to enable the use of a range of resilience mechanisms into the design and operation of a system.}, journal={Volume 13: Safety Engineering, Risk, and Reliability Analysis}, publisher={American Society of Mechanical Engineers}, author={Diaconeasa, Mihai A. and Mosleh, Ali and Morozov, Andrey and Tai, Ann T.}, year={2020}, month={Jan} }
 @article{wang_wu_diaconeasa_yan_mosleh_2020, title={On the Use of the Hybrid Causal Logic Methodology in Ship Collision Risk Assessment}, volume={8}, ISSN={["2077-1312"]}, url={https://www.mdpi.com/2077-1312/8/7/485}, DOI={10.3390/jmse8070485}, abstractNote={A ship collision accident is one of the most dangerous and common types of maritime accidents. Traditional probabilistic risk assessment (PRA) of ship collision accidents is a methodology that can be adopted to ensure maritime safety. Nevertheless, a need for better approaches to model human behavior, such as risk identification, communication, and decision-making, has been identified. Such advanced PRA methods require a more explicit way of taking human factors into consideration than the traditional risk assessment methods. Hybrid causal logic (HCL) is an advanced PRA method due to its unique three-level framework that includes event sequence diagrams, fault trees, and Bayesian networks, which makes it suitable for modeling human behavior that is important to ship collision accidents. This paper discusses the applicability of the HCL methodology for the ship collision accident. Firstly, the event sequences of typical ship collision accidents are summarized based on the study of 50 accident investigation reports. Then, fault trees for mechanical failure events and the Bayesian networks for human error events are constructed to analyze the events in a structured way at a more detailed level. Finally, the three main end-state types of ship collision avoidance scenario have been quantified. The result of the probability of a ship collision accident is verified by estimating the annual frequency of collision accidents in the Singapore Strait. Comparing with the historical data, the estimation results are quite near to the real case. By taking advantage of the HCL methodology, the modeling of ship collision scenarios can be carried out at a deep logical level. At the same time, it is possible to combine a detailed analysis of various primary events with a comprehensive analysis at the system level.}, number={7}, journal={JOURNAL OF MARINE SCIENCE AND ENGINEERING}, publisher={MDPI AG}, author={Wang, Tengfei and Wu, Qing and Diaconeasa, Mihai A. and Yan, Xinping and Mosleh, Ali}, year={2020}, month={Jul} }
 @inproceedings{jafary_rabiei_diaconeasa_masoomi_fiondella_mosleh_2018, title={A survey on autonomous vehicles interactions with human and other vehicles}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85063138117&partnerID=MN8TOARS}, booktitle={PSAM 2018 - Probabilistic Safety Assessment and Management}, author={Jafary, B. and Rabiei, E. and Diaconeasa, M.A. and Masoomi, H. and Fiondella, L. and Mosleh, A.}, year={2018} }
 @article{diaconeasa_mosleh_2018, title={Branching rules and quantification based on human behavior in the ADS-IDAC dynamic PRA platform}, DOI={10.1201/9781351174664-219}, journal={Safety and Reliability – Safe Societies in a Changing World}, publisher={CRC Press}, author={Diaconeasa, M.A. and Mosleh, A.}, year={2018}, month={Jun}, pages={1749–1756} }
 @inproceedings{diaconeasa_mosleh_2018, title={Branching rules and quantification based on human behavior in the ADS-IDAC dynamic PRA platform}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85058130438&partnerID=MN8TOARS}, booktitle={Safety and Reliability - Safe Societies in a Changing World - Proceedings of the 28th International European Safety and Reliability Conference, ESREL 2018}, author={Diaconeasa, M.A. and Mosleh, A.}, year={2018}, pages={1749–1756} }
 @inproceedings{diaconeasa_mosleh_2018, title={Development of a software platform for pipeline health monitoring and management}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85063123667&partnerID=MN8TOARS}, booktitle={PSAM 2018 - Probabilistic Safety Assessment and Management}, author={Diaconeasa, M.A. and Mosleh, A.}, year={2018} }
 @inproceedings{diaconeasa_mosleh_2018, title={Discrete dynamic event tree uncertainty quantification in the ADS-IDAC dynamic PSA software platform}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85063155237&partnerID=MN8TOARS}, booktitle={PSAM 2018 - Probabilistic Safety Assessment and Management}, author={Diaconeasa, M.A. and Mosleh, A.}, year={2018} }
 @article{diaconeasa_mosleh_2018, title={HYPRA}, DOI={10.1201/9781351174664-220}, journal={Safety and Reliability – Safe Societies in a Changing World}, publisher={CRC Press}, author={Diaconeasa, M.A. and Mosleh, A.}, year={2018}, month={Jun}, pages={1757–1763} }
 @inproceedings{diaconeasa_mosleh_2018, title={HYPRA: A hybrid static-dynamic PRA software platform}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85058090465&partnerID=MN8TOARS}, booktitle={Safety and Reliability - Safe Societies in a Changing World - Proceedings of the 28th International European Safety and Reliability Conference, ESREL 2018}, author={Diaconeasa, M.A. and Mosleh, A.}, year={2018}, pages={1757–1766} }
 @inproceedings{diaconeasa_mosleh_2018, title={Performing an accident sequence precursor analysis with the ADS-IDAC dynamic PSA software platform}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85063132484&partnerID=MN8TOARS}, booktitle={PSAM 2018 - Probabilistic Safety Assessment and Management}, author={Diaconeasa, M.A. and Mosleh, A.}, year={2018} }
 @inproceedings{wu_diaconeasa_mosleh_2018, title={The impact of time-varying operating parameters on the corrosion rate and depth of gas pipelines}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85063152604&partnerID=MN8TOARS}, booktitle={PSAM 2018 - Probabilistic Safety Assessment and Management}, author={Wu, K.Y. and Diaconeasa, M.A. and Mosleh, A.}, year={2018} }
 @inproceedings{diaconeasa_mosleh_2017, title={The ADS-IDAC dynamic platform with dynamically linked system fault trees}, volume={1}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85047838434&partnerID=MN8TOARS}, booktitle={International Topical Meeting on Probabilistic Safety Assessment and Analysis, PSA 2017}, author={Diaconeasa, M.A. and Mosleh, A.}, year={2017}, pages={482–491} }
 @book{driscoll_baglietto_buongiorno_lester_brady_arnold_2015, title={Optimization of Deep Borehole Systems for HLW Disposal}, url={https://www.osti.gov/biblio/1223390-optimization-deep-borehole-systems-hlw-disposal}, DOI={10.2172/1223390}, abstractNote={The objective of the research proposed here is to provide a comprehensive evaluation of the deep borehole option for disposal of high level nuclear reactor waste. For purposes of this work a deep borehole repository consists of a grid of individual oil-well type holes drilled 4 or 5 km deep into granitic bedrock, where the ambient chemistry is reducing in nature, and the host rock has exceptionally low permeability – both of which give high assurance of confinement. This project builds upon a long history of prior work carried out by the collaborating university and national laboratory partner. It is conceptualized in part as a response to the recent report to the Secretary of Energy by the Blue Ribbon Commission on America’s Nuclear Future, which identified deep boreholes as an alternative to shallower mined repositories well worth evaluation. As they note: “...the subcommittee has also identified deep boreholes as a potentially promising technology for geologic disposal that could increase the flexibility of the national system for nuclear waste management, and therefore merits research, development and demonstration.” The proposed work is naturally structured as a sequence of series/parallel linked models starting with ingress of water through natural and engineered barriers to contact with aged HLW, progressive release therefrom, followed by transport to and through a caprock barrier, and then penetration of overburden into the biosphere, where hypothetical future inhabitants are exposed to radionuclide-bearing well water. We will collect/adapt/improve/develop/exercise the requisite modules as required, followed by their linkage into an overall performance predictor program. Documentation will thus accumulate in stage-wise fashion, culminating in a probabilistic assessment of the degree to which waste sequestration can be achieved as a function of the dominant site and borehole design parameters such as host and caprock/plug permeability. Estimates of waste disposal costs in terms of dollars per kilogram of initial heavy metal irradiated in light water reactors will also be made.}, author={Driscoll, Michael ; and Baglietto, Emilio ; and Buongiorno, Jacopo ; and Lester, Richard ; and Brady, Patrick ; and Arnold, B. W.}, year={2015}, month={Sep} }