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DOE OSTI2023

Waste Attributes of SMRs Scheduled for Near Term Deployment

This is a short presentation as part of a "roundtable" panel on Back-end Fuel Cycle Implications of Advanced Reactor Fuel Cycles. It covers an evaluation of waste generation rates projected for small modular reactors expected to be constructed this decade which are compared to a reference gigawatt-scale light water reactor like those in the current commercial fleet. For ease of comparison, results are normalized per unit of electricity generated.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2023

Exploring the Potential of Factory Installed Solar + Storage for Homebuilding

In recent years, an increasing number of grid disruptions due to intense weather events, natural disasters, and high peak loads resulted in increased interest in energy-resilient homes. Solar + storage (S+S) as an energy resiliency solution can provide continuity, onsite generation, and backup power during critical events. This project explored factory-installed solar plus storage (FISS) to overcome first cost and installation barriers and bring this resiliency solution to scale for single-family affordable and market-rate homebuyers. Guided by the principles of Lean manufacturing, the team explored how factories building high-performance zero energy modular homes can incorporate S+S into their existing construction system while improving quality and productivity and reducing the costs of the resilient energy system.

ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION,↗
DOE OSTI2023

Intern Poster Session

This poster has been developed for display during the 2023 Intern Poster Session. The poster is apart of the Nuclear Research and Experiments category. The focus of this poster is on the modifications made to the design of an integral effect test (IET) facility currently being designed for a new Small Modular Reactor (SMR) design. My contributions made to the IET facility are laid out along with an explanation on some of the aspects of designing a new nuclear reactor. This poster covers the ideas and importance of scaling and IET facilities with the context of the standards set by the NRC. There are also graphics of some other examples of IET facilities developed for other reactor designs. My contributions include designing the piping and instrumentation layout of the IET facility using CAD software. This is a key step in the process of designing this IET facility and needs to be designed to avoid excessive head loss.

42 ENGINEERING↗
DOE OSTI2016

Simulation of fission gas diffusion in UO{sub 2} by vacancy clusters

The low solubility of fission gas in nuclear fuel leads to inter- and intra-granular bubbles. These bubbles affect performance of the fuel rod and increase the fuel temperature through the increase of porosity in the fuel pellets and decreased thermal conductivity across the pellet-clad gap as gas is released into the plenum. The nucleation, growth, and inter-connectivity of the fission gas bubbles ultimately depend on the diffusivity of gas atoms through the fuel matrix. Using mechanisms and data previously established from density functional theory (DFT) and empirical potential calculations, diffusion and reaction models have been derived for xenon atoms, uranium atoms, and vacancies in the substitutional and interstitial locations. Although similar to previous models, the diffusion and reaction rates have been re-derived in a more robust manner. Previous studies have under-predicted the experimentally observed diffusivity of xenon atoms in UO{sub 2}, however it has been previously shown that by including xenon atoms bound to two vacancies, the calculated diffusivity approaches the measured data. The derived model for species diffusion and inter-species reactions has been implemented in the MARMOT phase-field code in a modular structure so as to capture the enhanced diffusion of xenon due to bound gas + vacancy-cluster movement. The MARMOT code allows for the diffusion, reaction, and source rates to be solved simultaneously, resulting in steady state or transient concentrations of each species, and ultimately the diffusion behavior of xenon atoms. By including the diffusion of clusters of different combinations of xenon and vacancies, the calculated diffusivity more closely captures the measured diffusivity of xenon when using preliminary parameters. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2017

Applying State-of-the-Art Tools for Safety-Optimized D and D - 17410

Decommissioning, Demolition and Disposal of 'hot' facilities (D3) is a relatively new science to the extent it has been part our public consciousness for ∼50-years. Due to the high hazard of uncontrolled exposure and the possibility of environmental release, the technologies applied to D3 have not embraced many of the recently developed engineering tools, especially those that leverage the digital and optical advances of the past 10-years. This summary paper provides an overview of how we are layering readily available technologies with sophisticated techniques to D3, ranging from agile program management to advanced modular construction to augmented reality. Using this approach, we are significantly improving safety and ALARA aspects while saving costs, optimizing schedules, maintaining quality and engaging the customer and the regulator in the D3 environment. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Solutions and Challenges Posed by the Increasing Use of Technology Within the Nuclear Industry - 18023

Whereas the increasing influence of technology within the nuclear industry can be seen by many as providing significant advancements and solutions across many areas of the sector - it can also be seen to conversely represent a considerable number of challenges. Unlike the well-publicised technological advancements that have accelerated both operations and decommissioning at nuclear facilities around the world, the challenges that technology have brought to the nuclear industry are either not fully understood or have yet to be entirely assessed. One of the greatest technological benefits to the nuclear industry exists from the increased use of robotic technologies - specifically unmanned aerial vehicle (UAV) systems and other autonomous platforms, as part of routine and emergency site monitoring. The use of this technology by other (unauthorised) parties, however, represents a significant challenge, and one that has yet to be fully un-assessed. Other technologies, their advantages and challenges within the nuclear industry, discussed in this work include the potential / growing use of Small Modular Reactor (SMR) systems and the 'Internet of Things' (IoT). (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2016

A Scaling-based Applicability Assessment of the CAER Integrated Systems Test Facility

This paper presents a scaling-based applicability assessment of the Integrated Systems Test (IST) facility located at the Center of Advanced Engineering Research in Forest, Virginia. The assessment draws upon both traditional and contemporary scaling methods, seeking an optimal representation of light water reactor (LWR) and small modular reactor (SMR) characteristics during design-basis events. Based on published LWR loss-of-coolant-accident phenomena identification and ranking tables compiled with a similar assessment completed by BWXT mPower, Inc., for the mPower{sup TM} SMR, the phenomena considered in the IST design include break flow, decay heat, loop thermal-hydraulics, and primary-to-secondary heat transfer. Among these, the single- and two-phase natural circulation and system depressurization, by association to loop thermal-hydraulics, were the principal challenges. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2018

Panel reports session

This section brings together the reports of the 31 panel sessions listed below: - Avoiding the Human Capital Cliff in the DOE (PS22); - Implementing Technically-Based Cleanup; US DOE Balancing Regulatory and Fiscal Complexity (PS24); - United Kingdom - Remediation of Sellafield Legacy Ponds and Silos (PS25); - Aligning Decision-Making to Deliver Timely Results in Large Clean-up Programs (PS38); - Transition to Government Owned-Contractor Operated Site at Canadian Nuclear Laboratories (PS39); - Emerging Middle East Nuclear States' Status and Plans (PS40); - NPP Panel on Waste Management (PS41); - Robotics - International Innovations in Robotic Decommissioning Technology (PS43); - Fukushima Panel (1/2): Japan Fukushima Daiichi Decommissioning Update (PS54); - Fukushima Panel (2/2): Update on the Revitalization of Fukushima and the Surrounding Area (PS55); - US DOE LLW On-Site Disposal: LLW Disposal Facility Federal Review Group Review Process (PS56); - Challenges in DOE HLW Tank Management: Facility Start-up and Waste Disposition (PS57); - Waste Management Planning for Utility Small Modular Reactors (PS58); - US Nuclear Power Plant Waste Management - LLW Disposal Issues (PS59); - DOE-EM Robotics and Emerging Technologies Road-map (4/8) (PS60); - Graduating Students and New Scientists and Engineers - Wants and Needs - Are Companies Even Listening? (PS63); - U.S. Nuclear Robotics: Yesterday, Today, Tomorrow (5/8) (PS74); - US DOE Mixed Waste: Proposals for Dealing with Problematic Waste Streams and Policy Changes (PS76); - Current and Emerging US NRC LLW Regulatory Topics (PS77); - Agency Perspectives (US and International) on the Use of Risk and Dose Assessment Tools (PS80); - Progress on Deep Repository Programs Around the World (PS81); - US DOE Procurement and Contracting Opportunities (PS82); - Collaboration across Borders to Deliver Cleanup and Decommissioning Challenges (PS93a); - DOE Mission Success through Application of Practices and Solutions (PS94); - Challenges in Cask Certification - International Perspectives (PS96); - Robotics: Leveraging Innovations in Science and Technology to Benefit Safety Performance (PS98); - DOE Panel: DOE EM Featured Office - Portsmouth/Paducah Project Office (PS109); - Robotics: Lessons Learned from Industrial Robotics Deployment that can be Applied to the Nuclear Field (PS110a); - Roundtable: DOE Radioactive Management - Energy Facility Contractors Group - Waste Management Working Group (EFCOG WMWG) (PS118); - Thursday Topical Session 'Management of Used Nuclear Fuel: Will the United States Reengage and Align with International Efforts' (PS124); - Remotely Operated Vehicles for Emergency, Disaster, and Operational Upset Response (PS125)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Design of a Thermal Energy Storage System for SMR's

A potential deployment strategy for Small Modular Reactors (SMR's) is in hybrid energy systems where the presence of intermittent energy sources (wind and/or solar) subjects the reactor to a time varying electric load (1). Proposed options for accommodating this load have included operating the reactor in a load follow mode, or operating the reactor at or near steady state and bypassing steam around the turbine directly to the condenser (2). Both of these strategies result in lost energy potential. With the large financial investment associated with a nuclear power plant there is strong economic incentive to run the plant at maximum capacity. One method to accomplish this is the installation of Thermal Energy Storage (TES) that can be charged when grid demand is less than 100% plant capacity. The thermal energy can then be recovered, either as a supplement to the power plant during peak demand times, or can be used for other processes (1). Sensible heat thermal energy storage systems have been proposed for solar energy systems (3). This paper describes such a system for SMRs. These results show the feasibility of a TES system alongside a nuclear power plant that can limit load following operations for the reactor. Load following results in a decrease of capacity factor for the plant along with imposing significant stresses to plant equipment. With the implementation of a TES system these stresses can be transferred from the nuclear plant to the TES system. Not only does this equate to a longer overall life of the plant's hardware, but it also will dramatically increase the capacity factor of the system. This increase in capacity factor will lead to an improved economic return over the lifespan of the reactor. Future development in the near term will focus on coupling the TES system to the dynamic response of the reactor and energy conversion system and developing the models necessary to implement the discharge mode. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2016

Code Validation of a SBLOCA test in SMART Integral Test Loop

Integrated small modular reactors (iSMRs) are favored because of their unique characteristics, such as enhanced safety without any large break loss of coolant accidents (LBLOCAs), low initial construction costs, and multi-use of desalination and electricity generation. Many iSMRs have been developed thus far. In Korea, an iSMR called SMART was developed after a thorough validation of the components and systems, and finally received its design certificate in 2012 for the first time in the world. To ensure the performance of its safety systems, an integral test loop, SMART-ITL, is constructed. It contains the primary system, secondary system, passive safety systems, and an auxiliary system. The passive safety systems include a passive residual heat removal system (PRHRS), passive injection system with a core makeup tank (CMT) and a safety injection tank (SIT), and an automatic depressurization system (ADS). The height is preserved while the diameter is scaled down to 1:7. A series of SBLOCA tests have been performed with 4 trains of PRHRS, 1 train of CMT and SIT, and ADS. In parallel with the experiments, simulation of a representative test has been conducted to track the underlying thermal hydraulics. SMART-ITL is an integral test loop for SMART and a series of SBLOCA tests for confirming the performance of passive safety systems have been conducted. In this paper, a system code simulation on a SBLOCA test using SMART-ITL is presented. The reactor vessel water level, break flow rate, and CMT and SIT water levels are predicted well. (authors)

42 ENGINEERING↗
DOE OSTI2019

Canadian Nuclear Laboratories Waste Management: Challenges and the Integrated Waste Strategy - 19160

Canadian Nuclear Laboratories (CNL) currently faces various waste management challenges and CNL's Integrated Waste Strategy is adapting to manage them. As Canada's premier nuclear science and technology organization, CNL is a global leader in developing peaceful and innovative applications from nuclear technology through its expertise in the scientific field, including physics, metallurgy, chemistry, biology and engineering. As demands change, CNL is shifting its focus to alpha therapies for cancer treatments and sustainable energy solutions. The next decade will see CNL decommission the sites it manages across Canada, whilst transforming Chalk River Laboratories (CRL) into a new, world-class facility which will have the capability to demonstrate the commercial viability of advanced reactor designs including Small Modular Reactors (SMRs). This is being enabled through an accelerated decommissioning program for all CNL operated sites, while renovating CRL, which includes revitalizing essential site infrastructure, and investment in new, world-class science facilities in a modern campus environment. With decommissioning and revitalization occurring simultaneously, the long-term strategy and vision for CNL presents some unique challenges to waste management. Therefore, integrated, collaborative and coordinated waste management is a vital component to ensuring a successful future. The Integrated Waste Strategy coordinates, and provides alignment of, waste management across CNL and: - Includes all CNL operated (Atomic Energy of Canada Limited (AECL) owned) sites; - Considers all CNL managed waste (including radioactive and non-radioactive operational, decommissioning, legacy and historic waste) for the planned lifetime of the sites; - Defines waste routes using a life cycle approach (from the generation of waste to final disposal) A baseline Integrated Waste Strategy and associated action plan to mitigate identified gaps and issues have been produced. A program of work is underway to close those gaps identified in a consistent, transparent, prioritized and justified manner. One of the key challenges is to ensure that waste management planning is completed effectively and in a timely manner. This will enable the provision of suitable and sufficient waste capability to meet CNL's long-term strategy. The Integrated Waste Strategy has been developed and maintained through engagement at all levels across CNL, ensuring buy-in of proposed solutions. Key process stakeholders include generators of CNL managed waste to ensure integrated consideration of legacy, current and future waste generation; waste management personnel to identify requirements, including processing, storage, transport and disposal; AECL as the client and waste liability owner; and the public to ensure they understand the 'big picture' regarding waste strategy. (author)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Building a Decommissioning Army - 19259

It is safe to say that Canada has, for the greater part, seen the end of large-scale commercial nuclear new build projects. In spite of a renaissance in the last decade, and the fact that nuclear is now widely viewed by many as the original green energy, refurbishment projects both underway and scheduled will likely be the last of the megaprojects. In a sense, the future of large-scale nuclear power generation is the end of large scale nuclear power generation. Just as the construction and operation of these facilities has, for decades, employed scores of highly skilled workers, so too will the decommissioning process. Today, Canadian decommissioning activities are first-of-kind (FOAK)projects. There are very few experts in the field and certainly no plan in place to educate and prepare the numbers of workers we will need to safely and successfully execute the programs. It is to this end that I propose a national education centre be created to recruit, educate and mobilize all manner of professionals needed to meet this challenge. In an effort to meet the human and technological needs of the industry in the future, I propose the development of a Canadian Institute where the students study and learn how to decommission a nuclear power plant. The student body of the institute would comprise graduate students with backgrounds in a wide variety of studies such as engineering, physics, chemistry, commerce, environmental studies, and communications. Collectively, their time spent at the institute shall not only prepare them for a career in nuclear but will also vastly improve the technical readiness level of the Canadian nuclear industry to transition from large-scale nuclear utilities to a future of small modular reactors (SMRs) and renewable energy resources. Staff at the institute would be selected from leaders in the industry -those who have shown a passion for nuclear and have demonstrated innovative problem solving and leadership. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Use of Micro-Gravity Sensors for External Fluid Level Monitoring in Waste and Nuclear Related Applications - 20315

There are a number of applications in nuclear energy and hazardous waste disposal that require monitoring of fluids under extreme environments, including high levels of temperature, pressure, toxicity and radioactivity. Many of these applications will benefit from a monitoring technique that is external and non-invasive. Currently the sensors used are invasive, must reside inside the pressurized vessels and must penetrate the vessel walls, which can create a weakness in the vessel. Additionally, instruments that are used inside such containers must be exceptionally hardened to the environment. Information Systems Laboratories (ISL) has developed an external mass (gravimetric) measuring technique for monitoring nuclear coolant in Small Modular Reactors (SMRs), which will also work for measuring fluid levels in waste tanks, that avoids the problems inherent in invasive sensors. It utilizes a COTS gravitational sensor of unprecedented accuracy, leveraged via proper sensor placement geometry, to detect fluid changes of small amplitude from an outside position, obviating the need to penetrate the vessel. The technique is called Gravisense{sup TM}. ISL has proven via simulation and experiment that this concept can be usefully applied to monitoring fluid levels in both nuclear reactors and large waste tanks. Numerical simulation algorithms were developed to calculate the gravity effect of small changes in water level, which were verified by experiments at the NIST Physical Simulator facility at the Oregon State University. The measured ultralow noise levels of the superconducting gravimeter type which utilizes a Niobium sphere suspended in a magnetic field to attain its phenomenal accuracy, demonstrated that fluid levels in SMRs can be measured at least to within 3 cm. Furthermore, the method can distinguish between a contained leak (from reactor to containment vessel) from an external leak (from reactor to outside of containment). Additionally, simulations of waste canisters that hold spent fuel rods show that the fluid level measuring accuracy can potentially do better than 1 cm accuracy by measuring from below the vessel, and judicious placement of sensors on top of large waste tanks can potentially achieve a very impressive 2 mm measurement accuracy. These encouraging results prove that the Gravisense{sup TM} technique for fluid determination can be very useful in nuclear energy generation, testing, and research, as well as in waste monitoring situations that are difficult to monitor via traditional sensing technology. We believe that the next step should be to test the technique on canisters of the type that are currently storing waste in various DOE locations. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

Operating displays - new concept: high performance displays - 118

New control rooms in Nuclear Power Plants using digital Distributed Control System (DCS) operated with software displays, are providing thousands of signals to the operating crew. When an event happens, the Flood of information provided to operators could obscure the initiator event increasing the operator response time, work load and complicating the selection of the actions to be performed. There are some initiatives that are trying to minimize the 'avalanche effect' as the alarm engineering filtering and prioritization or diagnostic displays. Likewise, new control rooms are lost the availability to know the plant status just with a quick glance to the panel indicators. Regarding Small Modular Reactors, where in some cases four operators should monitor and control twelve reactors, these problems are even more significant. The challenge is to find a solution, based on current digital systems, that supply information to operators in order to prevent events and take early actions to minimize or avoid any unexpected incident. In order to minimize human errors, Tecnatom has developed a specific set of displays, called 'High Performance Displays' (HPD) based on objectives, work environment limitation, and non-anticipated events. These displays are being design following the HFE standards: applying the NUREG-0711 elements to identify the information that they have to content and the NUREG-0700 to design the interface. The function of these displays is monitoring the plant situation in a way that the operators are able to recognize any potential event at a simple glance but controlling thousands of signals through pattern recognition, symmetries, regular polygons and colors. The objective of the HPD is to provide an integrated function minimizing the tunnel effect and reduce the workload during the diagnosis phase. Moreover, HPD enhance operators to take the right actions to anticipate the response to any event, even avoiding it, if possible This paper analyzes how HPD's have been design as well as presents the results of a preliminary validation of their capabilities. The preliminary validation is a reduce validation in a full scope simulator running two representative scenarios of abnormal and emergency operation. The analysis is focused on the first stage of the event, i.e. the detection phase, HPD's have been installed in a generic full scope simulator of a nuclear power plant, digital controlled. Both scenarios have been performed by two different operator crews. The first operator shift has worked with the conventional human machine interface, that is, displays similar to the ones currently installed in existing nuclear power plant with digital control. The second crew, reproduce the same scenarios but with HPD available. The studio collects preliminary data in order to compare results, draw lesson learned from the experience to improve HPD design, and find solutions in terms of reducing human errors, human workload, and increase the availability of the plant. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2017

Real-time supervisory control implementation of SmAHTR power plant - 143

This paper discusses an implementation of a supervisory control system for a nuclear power plant model using Small modular Advanced High Temperature Reactors (SmAHTR). The simulation operates in real-time using a network of computer agents, implemented on Raspberry Pi's (RPi's), where each major task is performed by one or more RPi's running calculations in parallel. The system architecture contains local, module, master, and operator actions to automate all aspects of the plant. Local level controllers run individual control loops to ensure the desired reference signals are met. The module level controllers set the local level reference signals within each SMR unit and detect sensor and actuator failures to adjust those reference signals as needed. Master level controllers balance plant power by calculating required heat power from each reactor and electric power from each generator and sending that data to the module controllers. Finally, the operator level contains an operator interface to summarize data and faults gathered through the controller levels, with options to review plant and reactor details as desired. This control implementation allows the plant to run autonomously, load follow a desired electrical power curve, and detect a growing number of fault scenarios. Ultimately, this type of supervisory control system will reduce labor-intensive surveillance and testing and allow fewer operators to more safely monitor an entire plant. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2017

Analysis of a nuclear hybrid energy system using absorption chillers and stratified chilled-water storage with an mPower reactor - 187

The intermittency of renewable energy technology, such as wind and solar power, puts strain on electric grids, often forcing carbon-based and nuclear sources of energy to operate in a load follow mode. Operating nuclear reactors in a load-follow fashion is undesirable due to the associated thermal and mechanical stresses placed on the fuel and reactor components. Various methods of Thermal Energy Storage (TES) can be coupled to nuclear (or renewable) power sources to help absorb grid instabilities caused by daily load demand changes and renewable intermittency. This is known as a Nuclear Hybrid Energy System (NHES). Previous research has found that a stratified chilled-water storage tank can help displace peak cooling loads to off-peak hours. In this study, a dynamic single effect, lithium bromide absorption chiller model was developed as a callable FORTRAN subroutine. Cooling towers, a stratified chilled-water storage tank, and cooling loads characteristic of a large campus were included to form a comprehensive TES model. This TES model was coupled to a high-fidelity mPower sized Small Modular Reactor (SMR) FORTRAN code that provides the transient behavior of primary and secondary-side components. Control algorithms based on excess capacity and conditions in the stratified chilled-water storage tank were used to determine when to divert low-pressure steam from the turbines to the absorption chillers in order to keep reactor power near steady-state. Simulation results depict how the TES system and SMR interact, and demonstrate that stratified chilled-water storage is a viable TES technology for an SMR in a NHES. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2017

Qualified display system architecture - 246

There is a need in the nuclear industry for a Qualified Display System (QDS) architecture as described in this paper. The function of the QDS is to process and display Regulatory Guide 1.97 post accident monitoring parameters. The QDS is implemented on the Lockheed Martin Field-Programmable Gate Array (FPGA) based Nuclear Protection and Control (NuPAC) digital platform, coupled with a Qualified Display Controller (QDC) and a Safety Display Unit (SDU). The QDS is designed to meet the requirements of IEEE 603-1991 (endorsed by Regulatory Guide 1.153, Rev. 1), IEEE 497-2002 (endorsed by Regulatory Guide 1.97, Rev. 4), and IEEE 7-4.3.2- 2003 (endorsed by Regulatory Guide 1.152, Rev. 3). The QDS is designed with flexibility such that it can be implemented in an advanced reactor design, Small Modular Reactor (SMR) with any cooling medium, or digital upgrade project for an operating nuclear plant. The QDS has four independent and redundant divisions. Each division has five layers in the architecture: Process variable input signals; Process Protection Logic (PPL); Algorithm Logic (AL), Interface Panel (IP); and Safety Display Unit (SDU). The QDS meets the following design criteria: redundancy, independence, predictability and repeatability, and diversity capability. The QDS architecture also meets the simplicity design principle. The QDS architecture design provides flexibility in the implementation in a plant. The QDS can be implemented in the design of a new advanced plant or as a digital upgrade in an operating plant. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2017

Temperature compensated transfer function for probability of detection (POD) in high temperature ultrasonic NDE using low temperature signals - 249

Ultrasonic piezoelectric based transducers offer the potential for in-coolant NDT measurements and imaging required at high temperature for the safe operation of advanced small modular reactors (SMRs). Current work estimates a significant 97% reduction in the probability of detection (POD) for an artificial flaw size of 2{lambda} due to degradation of the transducer performance at elevated temperature. The source of variability for POD in the current work is the temperature dependence of material matrix of piezoelectric material PZT-5A used in the sensor. The physics based model developed using finite element method quantifies reduction in the scattering amplitude for the side drilled hole (SDH) from 15 C to 195 C. Using model assisted probability of detection (MAPOD) approach, sensor temperature effect on the POD is demonstrated for SDHs in the low carbon steel specimen. Scattering amplitudes for the room temperature simulated data is validated with the experimental data. A temperature correction factor and transfer factors are reported to transform the simulated temperature effect from physics based model to the experimental data for estimation of high temperature POD using low temperature ultrasonic measurements. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗