Many cities, states, utilities, and public commissions are setting energy standards that aim to reduce carbon emissions. In order to realize a clean and resilient energy future, new methods of energy production, distribution, and use will be required. Renewable energy technologies are currently being deployed in significant numbers around the world in response to the desire to reduce emissions, coupled with decreasing costs for these technologies. However, despite this growth, data reported in the International Energy Agency (IEA) Future of Nuclear report that was released in May 2019 indicate that the fraction of clean energy contributions to electricity generation has not changed over the last 20 years. This unexpected trend results from the increasing penetration of variable sources driving nuclear energy out of the market in some regions, resulting in the shutdown of some large-scale, non-emitting plants when non-emitting renewable resources are added to the grid. The advent of historically low-cost renewable generation sources, alongside low cost and high availability of natural gas, has driven down the price of electricity, decreasing the minimum baseload generation required to meet load at certain times of the day or year. These factors serve to diminish the role of traditionally baseload nuclear generation. Many nuclear plants have responded to increasing volatility in net demand by operating flexibly, reducing power output to reduce the financial impact to the plant from very low or negative market prices. This practice preserves the contribution of nuclear energy to grid stability and reduces economic losses associated with negatively-priced electricity sales, but it does not reduce the plant operating costs. Nuclear energy is a proven low-emission option that can provide consistent, dispatchable power to meet electricity demands while also providing high quality heat that can meet energy demands beyond the electricity sector-energy system design should seek to maximize these assets. This roadmap defines proposed integrated nuclear-renewable energy systems and identifies key technology gaps to realizing deployment of commercial scale systems for the production of a variety of electric and non-electric products. Integrated energy systems (IES) under consideration could incorporate multiple energy generation resources and energy use paths, with a focus on low-emission technologies such as nuclear and renewable generators. Together these technologies provide affordable, reliable, and resilient energy while simultaneously reducing environmental emission of CO2 and greenhouse gases (GHGs). IES are cooperatively-controlled systems that dynamically apportion thermal and/or electrical energy to provide responsive generation to the power grid. They are composed of multiple subsystems, which may or may not be geographically co-located, including a thermal energy generation source (e.g., nuclear), a turbine that converts thermal energy to electricity, additional electricity generation source(s) (e.g., renewable ge...

The objective of the current scope was to complete single primary heat extraction and removal emulator (SPHERE) assembly and demonstrate the operation of the SPHERE facility. The initial testing consisted of vacuum operation of a sodium heat pipe. The temperature was measured at 10 evenly spaced points along the heat pipe. Additional exterior thermocouple measurements were also taken on the exterior of the heat pipe to confirm the similarity of thermowell temperatures to exterior heat pipe temperature measurements. The initial test was successfully completed and results measured at INL are consistent with the data from the manufacturer.

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This document provides a summary of the experimental capabilities and activities developed and currently performed under the U.S. Department of Energy's (DOE's) Microreactor Program. These capabilities, along with other laboratory capabilities, are available to support developer and other stakeholder needs. Specific experimental capabilities described in this document include the single primary heat extraction and removal emulator (SPHERE), the microreactor agile non-nuclear experimental test bed (MAGNET), microreactor applications research validation and evaluation (MARVEL), yttrium hydride fabrication, the Hypatia critical experiment series, and a brief overview of the National Criticality Experiments Research Center (NCERC), which provides the platform to conduct experiments amd training with critical assemblies and fissionable material.