Technical Readiness and Gaps Analysis of Commercial Optical Materials and Measurement Systems for Advanced Small Modular Reactors

Abstract

Energy Research and Development Roadmap and industry stakeholders by evaluating optically based instrumentation and control (I&C) concepts for advanced small modular reactor (AdvSMR) applications. These advanced designs will require innovative thinking in terms of engineering approaches, materials integration, and I&C concepts to realize their eventual viability and deployment. The primary goals of this report include:1. Establish preliminary I&C needs, performance requirements, and possible gaps for AdvSMR designs based on best-available published design data.2. Document commercial off-the-shelf (COTS) optical sensors, components, and materials in terms of their technical readiness to support essential AdvSMR in-vessel I&C systems.3. Identify technology gaps by comparing the in-vessel monitoring requirements and environmental constraints to COTS optical sensor and materials performance specifications.4. Outline a future research, development, and demonstration (RD&D) program plan that addresses these gaps and develops optical-based I&C systems that enhance the viability of future AdvSMR designs.The DOE-NE roadmap outlines RD&D activities intended to overcome technical barriers that currently limit advances in nuclear energy. As part of this strategy, DOE-NE is sponsoring research on advanced reactor supportive technologies to reduce the identified barriers. Key challenges that must be overcome include the high capital costs to develop nuclear power plants, maintaining safety performance as the reactor fleet expands, minimizing nuclear waste, and maintaining strong proliferation resistance. AdvSMR designs are a major component of this strategy, because these designs offer a number of unique advantages. The modular and small size of AdvSMR designs naturally lead to reduced capital investments and, potentially, construction savings through factory fabrication. However, new economic and technical challenges accompany the many attractive features offered by AdvSMR designs. Specifically, the modest power output of AdvSMRs does not provide the economy of scale afforded by large reactors. In addition, many of the AdvSMR designs operate at much higher temperatures than lightwater reactors and require instrumentation to withstand harsh, in-vessel environments arising from unconventional, chemically aggressive coolants and unique reactor system configurations.Addressing these I&C challenges will be critically important to the AdvSMR development program to ensure the viability and future success of advanced reactor designs. Solutions will likely be found through evolution of conventional reactor technology, and the development of entirely new concepts. Early pressure/boiling water reactors used conventional I&C technologies (e.g., thermocouples, ionchambers, strain-gauge pressure sensors) to satisfy design requirements. Because these technologies worked well in the relatively low-temperature reactor designs, the demand for alternate I&C technologies was limited. At the time, optical-based reactor monitoring concepts were g...

Technical Report on Preliminary Methodology for Enhancing Risk Monitors with Integrated Equipment Condition Assessment

“…These include measurements that are sensitive to component condition (such as vibration or current/voltage) as well as measurements of the operational environment (stressors). Ongoing research into sensors (such as that documented in Anheier et al (2013) and Daw et al (2012)) will be leveraged where possible.…”

“…These may include process measurements (e.g., flow, temperature, and pressure), performance measurements (e.g., pump efficiency), or direct measurements (e.g., vibration and acoustic emissions). Challenges from the harsh environments in AdvSMRs may necessitate novel measurement methods, such as optical (Anheier et al 2013) measurements of process parameters, or the use of sensors tolerant to these conditions (Daw et al 2012). These measurements are then applied to analysis algorithms to map the available measurements to condition indicators (shown in Figure 1.1 as ECA).…”

Summary of the Preliminary Optical ICHMI Design Study: A Preliminary Engineering Design Study for a Standpipe Viewport

“…Several optical window materials, including chemical vapor deposited (CVD) diamond, ALON ® , spinel, sapphire, and fused silica, were identified to have high technical readiness for the standpipe viewport application (Anheier et al 2013). The technical readiness was evaluated in terms of optical, thermal, structural, and chemical compatibility properties and radiation resistivity of these materials for near reactor vessel head (lid) applications.…”

“…A prior report (Anheier et al 2013) identified molybdenum, tungsten, and rhodium mirrors as excellent candidates for AdvSMR applications, because of their extremely high radiationresistance and mechanical durability. Custom tungsten and rhodium mirrors are available from several vendors; however, molybdenum mirrors are COTS items.…”

“…Optical-based measurement and sensing systems for AdvSMR applications have several key benefits over traditional instrumentation and control systems used to monitor reactor process parameters, such as temperature, flow rate, pressure, and coolant chemistry (Anheier et al 2013). Direct and continuous visualization of the in-vessel components can be maintained using external cameras.…”