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At least 613 records · Page 34

Posiva's Onkalo{sup R} FST (Full-Scale In Situ System Test) - 20051

The FST - Full-scale In Situ System Test - is a unique full-scale demonstration of disposal system in crystalline host rock. The FST was constructed in ONKALO{sup R} demonstration area at the disposal depth of 420 metres, in Posiva's actual final disposal facility at Olkiluoto, Finland. The demonstration has included design, manufacture, installation and comprehensive instrumentation for monitoring the evolution of the disposal system and its components. The demonstration tunnel and experimental deposition holes were excavated in 2010 in ONKALO to address that they can be excavated to meet the requirements set for them. Two experimental deposition holes, bored in the floor of the tunnel, host each a canister surrounded by bentonite clay buffer rings/segments in the holes. Inside the canisters are heating elements to simulate decay heat emitted by spent fuel. The tunnel part used for the test is about 50 m long and it was filled with bentonite clay backfill after the installation of the canisters and buffer components. The tunnel is closed with a steel-reinforced concrete plug. The test is equipped with 500 sensors to monitor early evolution of the system. To forecast the evolution of the system, a mathematical model has been created. (authors)

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Update to the Performance Assessment for the Savannah River Site Saltstone Disposal Facility - 20124

In 2019, Savannah River Remediation developed a revision to the performance assessment (PA) on behalf of the U.S. Department of Energy (DOE) Savannah River Operations Office (SR) for the near-surface disposal of low-level waste at the Savannah River Site (SRS) Saltstone Disposal Facility (SDF). Soluble waste from SRS Tank Farms undergoes salt processing to remove cesium and other high activity constituents. The low-activity decontaminated salt solution (DSS) is then immobilized by mixing it into a cementitious waste form known as saltstone. After mixing, the saltstone is poured into leak-tight concrete vaults, known as saltstone disposal units (SDUs), where the waste form cures. By the time of facility closure, the SDF is expected to consist of 15 SDUs with a combined capacity of 1.06 E+09 L (280 Mgal) of cured saltstone. The facility operates under a Disposal Authorization Statement (DAS) from DOE and a permit from the South Carolina Department of Health and Environmental Control (SCDHEC). Since the start of operations in 1990, the SDF has received almost 6.7 E+07 L (18 Mgal) of DSS, resulting in the safe disposal of 2.7 E+16 Bq (7.3 E+05 Ci) of activity. Due to the radioactive decay of short-lived contaminants, the total remaining activity in the disposed waste is estimated to be approximately 1.4 E+16 Bq (3.9 E+05 Ci), as of September 2018. The Disposal Authorization Statement requires a demonstration that the system of engineered and natural features of the disposal facility will limit releases from the facility and be protective of human health and the environment for at least the next 1,000 years. The long-term performance of the facility was evaluated under the requirements of the DoE's Radioactive Waste Management Manual (US DOE Manual 435.1-1). Simulations were performed to demonstrate that the disposal facility would meet performance objectives specified in the manual. The evaluation was based on numerical models that simulate the releases of contaminants from the saltstone waste form. Contaminants were transported through groundwater and air pathways to points of assessment to evaluate compliance. In addition, the potential consequences of an inadvertent human intrusion (IHI) were also evaluated. In accordance with the guidance and recommendations in US DoE's technical standard for DAS, deterministic and probabilistic analyses were performed to demonstrate the SDF system, which includes the engineered cover system, the SDUs, the waste form, and the natural features of the site, provides a reasonable expectation that saltstone disposal will meet performance objectives. Post-closure doses to future members of the public (MOP) were evaluated; dose estimates from the air pathway were well below the 1.0 E-04 Sv/yr (10 mrem/yr) performance objective within 1,000 years, and the calculated doses to the MOP from all exposure pathways, including the groundwater and air pathways, were well below the 2.5 E-04 Sv/yr (25 mrem/yr) performance objective within 1,000 years. Doses following an assumed intrusion event within the facility boundaries were well below the IHI performance objectives, where the acute IHI dose was below the acute IHI dose performance objective of 5.0 E-03 Sv (500 mrem) and the chronic IHI dose was below the chronic IHI dose performance objective of 1.0 E-03 Sv/yr (100 mrem/yr) within 1,000 years. (author)

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Progress on Advancing the Robotic Air-slot Volumetric Inspection System (RAVIS) for Hanford Under-tank Inspection - 20519

The 27 in-service double-shell tank (DST) systems at Hanford provide interim storage for nearly 56 million gallons of nuclear and hazardous chemical legacy waste. The safe and reliable storage of the waste is critical to the site's extended cleanup mission. While in service, the leak integrity of the DSTs must be demonstrated to satisfy the Washington Administrative Code, inform decisions on tank management, and gauge fitness for continued service beyond originally intended design lives. The carbon steel plates and welds that comprise DST primary tank sidewalls and lower knuckles are routinely 'sampled' for volumetric non-destructive testing using ultrasonic inspection technology to determine whether corrosion pitting, cracking, or general corrosion are occurring that could compromise tank leak integrity. However, the carbon steel plates and welds that comprise the bottoms of primary tanks have not been thoroughly inspected since the DSTs were constructed (i.e., since 1968-1986) due to limited physical access to the exterior tank bottoms. The Robotic Air-slot Volumetric Inspection System, or 'RAVIS,' is being engineered to overcome the challenge of tank bottom in-service inspection. The system will be deployed under primary tanks within the small cooling channels/air-slots in the refractory pads upon which the tanks rest and will use ultrasonic guided wave inspection technology to volumetrically inspect physically inaccessible regions that make up ∼90% of a tank bottom, as well as regions that are physically accessible from the air-slots but comprise only ∼10% of a tank bottom. This paper describes the air-slot sensor and robotic deployment system and focuses on the testing approach and methods that are being applied to support (1) design feedback and performance acceptance (requirement verification) and (2) performance repeatability/reliability assessments (qualification) to ensure the RAVIS is prepared for successful inservice inspections of primary tank bottoms. Test progress made against the test plan, the results of 2019 testing, and the future outlook are included. (authors)

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A data base approach for prediction of deforestation-induced mass wasting events

A major topic of concern in timber management is determining the impact of clear-cutting on slope stability. Deforestation treatments on steep mountain slopes have often resulted in a high frequency of major mass wasting events. The Geographic Information System (GIS) is a potentially useful tool for predicting the location of mass wasting sites. With a raster-based GIS, digitally encoded maps of slide hazard parameters can be overlayed and modeled to produce new maps depicting high probability slide areas. The present investigation has the objective to examine the raster-based information system as a tool for predicting the location of the clear-cut mountain slopes which are most likely to experience shallow soil debris avalanches. A literature overview is conducted, taking into account vegetation, roads, precipitation, soil type, slope-angle and aspect, and models predicting mass soil movements. Attention is given to a data base approach and aspects of slide prediction.

Logan, T. L.↗

C-5 Electrical Substation (SWMU 066) Performance Monitoring Report

The C-5 Electrical Substation (C5ES) is a National Aeronautics and Space Administration (NASA) operated electrical power substation located at the John F. Kennedy Space Center (KSC), Florida. This facility has been designated Solid Waste Management Unit (SWMU) 066 under KSC’s Resource Conservation and Recovery Act (RCRA) Corrective Action program. This Performance Monitoring Report (PMR) presents the Interim Measure (IM) activities, including baseline sampling, air sparge system construction and operation, and performance monitoring, that were completed to remediate chlorinated volatile organic compounds (CVOC) in groundwater exceeding the Florida Department of Environmental Protection (FDEP) natural attenuation default concentrations (NADC).

Andrew Scott Starr↗

Launch Complex 34, SWMU Cc054 2021 DNAPL Source Zone Operations, Maintenance, and Monitoring, and Hot Spot 6 Air Sparge System Annual Performance Monitoring Report Cape Canaveral Space Force Station, Florida

This Annual Performance Monitoring Report (PMR) for the Dense Non-Aqueous Phase Liquid (DNAPL) Source Zone (DSZ) and Hot Spot 6 (HS 6) Air Sparge (AS) System presents the results of Year 12 operation of the hydraulic containment (HC) Interim Measure (IM), the results of performance monitoring direct-push technology (DPT) sampling and monitoring well sampling conducted in the DSZ, and the results of operations and performance sampling of the HS 6 AS IM at Launch Complex 34 (LC34), located at Cape Canaveral Space Force Station (CCSFS), Florida. Site-wide biennial LTM sampling was not conducted during this reporting period and is scheduled to be conducted in December 2022. The timeframe for activities documented in this PMR extends from April 1, 2021 to March 31, 2022. LC34 has been designated Solid Waste Management Unit CC054 under the Kennedy Space Center (KSC) Resource Conservation and Recovery Act Corrective Action Program. The objective of the HC IM at LC34 is to contain the DSZ and deep dissolved-phase trichloroethene (TCE) high concentration plume via operation of a hydraulic containment system (HCS). The pre-IM design 300 micrograms per liter (μg/L) TCE groundwater contour was used to establish the deep zone capture area for deep recovery wells, and the shallow zone capture area was defined by the DSZ. The system began operating in 2010, and in 2015, the system was expanded to provide HC for areas within the 300 μg/L TCE groundwater isocontours of HS 3 and 4. In 2018 and 2019, an investigation was conducted to re-characterize the DSZ, which included investigating TCE mass in Layer 7. This data was subsequently used to optimize the pumping rates of the HCS to more adequately capture residual contaminant mass. The operational period for Year 12 of the HCS was from April 1, 2021 to March 31, 2022. Operational runtime for the system was 94 percent during Year 12, with downtime events attributed to planned maintenance, system repairs, and power outages. As of March 31, 2022, a total of 285,712,801 gallons of groundwater containing 84,933 pounds of VOCs have been removed by the HCS. Influent concentrations of TCE have decreased since startup from approximately 280,000 µg/L (January 2010) to 12,000 µg/L (March 2022). During the reporting period, all effluent concentrations from the HCS (aqueous and vapor) were below regulatory reporting limits, indicating the system continues to operate as intended. Performance monitoring was conducted in December 2021 within the DSZ to evaluate TCE contamination. Groundwater samples were collected via DPT at nine locations, consistent with previous events in 2017, 2018, 2019, and 2020. Full vertical profile sampling was completed at each DPT from 8 to 98 ft bls, at 5 foot intervals. The DPT performance monitoring results are summarized in this PMR. The results revealed TCE remains at concentrations greater than 11,000 µg/L in the DSZ (1-percent solubility, indicative of DNAPL) at eight of the nine DPT locations at depths ranging from 8 to 98 ft bls. An overall increasing trend of TCE concentrations was observed in DPT samples during this reporting period, which may be due to several recovery wells that were turned off during the AS Pilot Study in the DSZ that operated from July 2021 to February 2022 (documented separately from this report). The maximum TCE concentration in 2021 was 15,400,000 µg/L in the 58 ft bls depth interval at DPT597 (previous maximum result in 2020 was 1,690,000 at 48 ft bls at DPT596). During the 2021 DPT event, the overall majority of TCE contamination was identified in the 58 ft bls interval (below Layer 4), where in the previous year the majority of mass was observed in Layer 4. This trend appears to indicate continued mass discharge from Layer 4 (fine-grained unit). In addition to DPT sampling, monitoring well samples were collected from deep wells in the DSZ area (Layers 7 and 8) to verify vertical delineation. All monitoring well results were non-detect or below cleanup levels, with exception of one well (IW0162, screened 105 to 115 ft bls, which is below the existing recovery well capture zone) where TCE was identified above cleanup target levels. The HS 6 AS system remained operational during the reporting period covered under this report. The HS 6 AS IM was initiated in 2018 with 160 AS wells, and expanded in 2019 with an additional 140 AS wells. Quarterly performance monitoring was reduced to semi-annual prior to this operational period. The results of the HS 6 system operation and semi-annual performance monitoring are summarized in this report. Semi-annual monitoring results collected in April and October 2021 show concentrations of contaminants of concern (cis-1,2-dichloroethene, trans-1,2- dichloroethene, and vinyl chloride) are generally decreasing and not impacting the surface water drainage canal, indicating the HS 6 IM is meeting objectives. Overall, the tasks associated with Year 12 operation of the HC IM and operation of the HS 6 AS IM were performed in accordance with the recommendations of the 2020 LC34 (Year 11) Operations, Maintenance, and Monitoring Report for DNAPL Source Zone, Site Wide LongTerm Monitoring, and Hot Spot 6 Air Sparging System PMR (NASA, 2021c). Evaluation of results from the HC IM and HS 6 IM show that these systems are operating as designed and meeting performance objectives.

trichloroethene↗

Application of Hybrid Optimization-Expert System for Optimal Power Management on Board Space Power Station

The space power system has two sources of energy: photo-voltaic blankets and batteries. The optimal power management problem on-board has two broad operations: off-line power scheduling to determine the load allocation schedule of the next several hours based on the forecast of load and solar power availability. The nature of this study puts less emphasis on speed requirement for computation and more importance on the optimality of the solution. The second category problem, on-line power rescheduling, is needed in the event of occurrence of a contingency to optimally reschedule the loads to minimize the 'unused' or 'wasted' energy while keeping the priority on certain type of load and minimum disturbance of the original optimal schedule determined in the first-stage off-line study. The computational performance of the on-line 'rescheduler' is an important criterion and plays a critical role in the selection of the appropriate tool. The Howard University Center for Energy Systems and Control has developed a hybrid optimization-expert systems based power management program. The pre-scheduler has been developed using a non-linear multi-objective optimization technique called the Outer Approximation method and implemented using the General Algebraic Modeling System (GAMS). The optimization model has the capability of dealing with multiple conflicting objectives viz. maximizing energy utilization, minimizing the variation of load over a day, etc. and incorporates several complex interaction between the loads in a space system. The rescheduling is performed using an expert system developed in PROLOG which utilizes a rule-base for reallocation of the loads in an emergency condition viz. shortage of power due to solar array failure, increase of base load, addition of new activity, repetition of old activity etc. Both the modules handle decision making on battery charging and discharging and allocation of loads over a time-horizon of a day divided into intervals of 10 minutes. The models have been extensively tested using a case study for the Space Station Freedom and the results for the case study will be presented. Several future enhancements of the pre-scheduler and the 'rescheduler' have been outlined which include graphic analyzer for the on-line module, incorporating probabilistic considerations, including spatial location of the loads and the connectivity using a direct current (DC) load flow model.

Momoh, James↗

FY2020 Rotating Bed Reactor for Iodine Removal from WTP Melter Effluent to Support DFLAW Start-Up

In Performance Assessment (PA) of the Hanford Integrated Disposal Facility (IDF), 129 I is a significant contributor to the risk. The 2017 IDF PA accounted for 0.22% of the total 129 I inventory in Hanford tank waste as residing in the solidified liquid waste from the Effluent Treatment Facility (ETF). However, recent estimates suggest that higher percentages of the iodine processed at the Hanford Waste Treatment and Immobilization Plant (WTP) may be present in the liquid waste routed to the Liquid Effluent Retention Facility (LERF) for eventual treatment at the ETF. In addition, a recent integrated melter test performed at the Vitreous State Laboratory (VSL) at The Catholic University of America (CUA) showed the possibility that a significant fraction (>50%) of the total iodine in the melter feed could be present in the aqueous waste stream destined for the ETF. This stream represents a combination of the Effluent Management Facility (EMF) evaporator overhead condensate and the liquid waste from the WTP off-gas caustic scrubber. Higher levels of 129 I in this stream could affect the LERF and ETF Hazard Categorizations as well as the acceptability of the solidified ETF liquid secondary waste brine for disposal at the IDF. Accordingly, there is a need to investigate and develop potential methods and processes to mitigate this risk. Washington River Protection Solutions, LLC (WRPS) tasked Atkins and VSL to perform development and testing work to evaluate potential methods for removal of iodine species from the waste stream routed to the LERF. In particular, the testing investigated the use of an Atkins-SpinIonic™ Rotating Bed Reactor (RBR) system as a potential alternative to conventional column-based ion exchange or absorption processes. The present report provides results obtained from testing with an RBR system for the removal of iodine from simulants of the projected WTP waste stream that discharges to the LERF.

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Integration, design, and construction of a CELSS breadboard facility for bioregenerative life support system research

Design criteria for the Biomass Production Chamber (BPC), preliminary operating procedures, and requirements for the future development of the Controlled Ecological Life Support System (CELSS) are discussed. CELSS, which uses a bioregenerative system, includes the following three major units: (1) a biomass production component to grow plants under controlled conditions; (2) food processing components to derive maximum edible content from all plant parts; and (3) waste management components to recover and recycle all solids, liquids, and gases necessary to support life. The current status of the CELSS breadboard facility is reviewed; a block diagram of a simplified version of CELSS and schematic diagrams of the BPS are included.

Prince, R.↗

Accelerating Nuclear-Integrated Data Centers in the USA: SWOT Analysis, Power-Thermal Management Strategies, and Industrial-Scale Demonstration and Potential Deployment

Driven by the growth in digital services, cloud computing, AI, and manufacturing, data centers face rising energy demands that challenge traditional power sources and cooling efficiency. This study explores using nuclear power to meet these demands, focusing on accelerated reactor technology deployment and highlighting needs such as N+1/N+2 power supplies and integrated power-thermal management. A SWOT analysis addresses grid connectivity, reactors, and site selection, particularly DOE sites. Reactor technology demonstration and deployment could be accelerated by leveraging test facilities such as MARVEL, MAGNET, TED, FAS, DOME, LOTUS, ATR, Energy System Proving Grounds, and upcoming Energy Launch Pads, along with modeling and simulation tools such as RELAP5, MOOSE, VERA, RAVEN, and FORCE. The potential power and thermal management options, including various cooling technologies, waste-heat utilization, and an industrial-scale demonstration plan, aim to accelerate the integration of nuclear power and data centers in the USA, while emphasizing community and stakeholder engagement and synergistic efforts.

21 - SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLAN↗

Energy Efficient Waste Heat Coupled Forward Osmosis for Effluent Water Management at Coal-Fired Power Plants

This project sought to evaluate the technical and economic viability of the Aquapod©, a transformational low energy (<200 kJ/kg water) waste heat coupled forward osmosis (FO) technology, to manage effluents, meet cooling water demands, and achieve water conservation in a coal-fired power plant environment. The Aquapod© process is innovative because it is heat-driven, avoids the evaporation of water, and uses no toxic chemicals such as ammonia or amines. The Aquapod© process accomplishes this using an aqueous two-phase system (ATPS) coupled FO process. The evaluation revealed that the Aquapod© process offers a pathway to exploit waste heat resources within a power plant to achieve flue-gas desulfurization (FGD) wastewater volume reduction and water recovery with minimal pretreatment. Water recovery of 80% from FGD wastewater was achieved with minimal pretreatment, exceeding the project target of 50%. The estimated electrical energy of 2.16 kWh/m 3 of water produced for the Aquapod© process met the project target of < 3.6 kWh/m 3 . The heat required for the process operation was approximately 186 kJ/kg of produced water, which was slightly lower than the project target of 200 kJ/kg. The estimated treatment cost for installing and operating the Aquapod© process in conjunction with a spray dryer evaporator to achieve zero-liquid discharge (ZLD) of the 100 gpm FGD wastewater was $13.24/m 3 over a 30-year lifetime. As a point of reference, this study’s host power plant currently incurs a cost of $3.70/m 3 – $8.87/m3 on a discharged volume basis to discharge its wastewater into the publicly owned treatment works (POTW) after physical-chemical treatment. Therefore, the Illinois power plant would incur an incremental cost increase of $4.37/m 3 – 9.54/m 3 to achieve ZLD using the Aquapod© and spray dryer combination. Ample opportunities exist to further lower the ZLD capital and operating costs in the next design iteration to attain pipe parity at the higher end of the site treatment costs.

01 COAL, LIGNITE, AND PEAT↗

PV DMFA [SWR-21-105]

The Photovoltaic Dynamic Material Flow Assessment (PV DMFA) model (also referred to here as “The model”) is a computational framework written in Python based on utility-scale PV electricity generation to quantify time-series stocks and flows of PV materials primarily in crystalline silicon PV technologies. The model evaluates cradle-to-cradle life cycle of utility-scale solar PV systems in the United States in the period 2000-2100. PV DMFA serves as a sustainability analysis tool to assess the impacts of different material circularity practices (i.e., reduce, reuse/refurbish, remanufacture, and recycle), PV module design shifts and sensitivity of material processing and technology related parameters to material installations, waste creation and raw material depletion in PV material supply chains. This tool enables advanced planning for future material needs and informs sustainable pathways for PV material management in the circular economy. This tool could be helpful to a wide range of stakeholders; Particularly, researchers and manufacturers looking for technoeconomic and/or environmental life cycle analysis (LCA) feedback for renewable energy (RE) systems.

Khalifa, SherifA.↗

Potential for Evaporation and In Situ Reaction of Organic Compounds in Hanford Supplemental LAW

The presence of regulated organic species in Hanford nuclear tank waste is assessed in this report, along with fate of the organics and possible evaporative treatment. A narrowed list of regulated organic species of concern is developed based upon published analyses, chemical properties like aqueous solubility, and chemical reactivity under alkaline conditions. Published analyses include tank headspace and liquid samples, review of chemical reagents formerly used at Hanford, and the Tank Waste Information Network System (TWINS). This work supports possible stabilization of Hanford Supplemental Low Activity Waste (SLAW) by grouting.

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Colloid-Facilitated Actinide Transport in a Cementitious-Impacted SRS Groundwater

The objective of this report is to provide a literature review relevant to the question of whether colloid facilitated transport of plutonium is enhanced in a cementitious groundwater system on the Savannah River Site (SRS). Contaminant transport is commonly described as taking place in a system with a mobile aqueous phase and an immobile solid phase. There has been an increasing awareness of a third phase, a mobile solid phase, also referred to as a mobile colloidal phase. Mobile colloids consist of organic and/or inorganic submicron-particles that move with groundwater flow. When radionuclides are associated with the mobile colloids, the net effect is that radionuclides can move faster through the subsurface system than would be predicted by transport models that do not include mobile colloids. It is important to distinguish between subsurface colloids and subsurface mobile colloids. The subsurface environment includes an enormous reservoir of colloids, but only a tiny fraction, if any, are mobile. Mobile colloid formation is commonly described as involving a three-step process: genesis, stabilization, and transport. It was concluded that there is a strong likelihood that submicron colloids of plutonium exist near the source term, (i.e., the genesis step is likely completed). While such particles have not been directly detected, it is highly likely that plutonium could either attach to submicron particles in the sediment or that submicron plutonium fragments exist at the source. However, the tendency for these plutonium colloids to move in the SRS subsurface is extremely low, especially in engineered cementitious environments where the ionic strength of the solution and the elevated concentrations of divalent cations greatly curtails colloid suspension stability (i.e., the stabilization step is likely not completed). Together these data strongly indicate that plutonium-bearing colloids would likely exist in the near field of a tank closure facility, but the colloids would be unlikely to be mobile, thereby providing a vector for enhanced transport. Under cementitious leachate impacted groundwater conditions, it is reasonable to assume plutonium transport occurs primarily as a two-phase system, a mobile aqueous phase and an immobile solid phase.

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Code Standard Evaluation for ASME AG-1-2019, Section FL

ASME AG-1 Section FL Deep Bed Sand Filters includes a requirement to use Special Test Sections to provide a representative assessment of the filter efficiency. The SRPPF project design basis is to test the entire filter bed (versus a representative sample) following the same basis methodology to test the existing filters at the Savannah River Site. Using a combination of: 1) the filter testing experience at SRS since the early 1970’s, 2) the methodology found in ASME AG-1 for testing high capacity HEPA filter housings and 3) requirements for stack or duct sampling systems published by the Environmental Protection Agency (EPA), the Special Test Sections methodology for Deep Bed Sand (DBS) filters in ASME AG-1 Section FL has been replaced with a methodology to test the entire DBS filter system.

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Investigating Uranium Corrosion in Magnesium-containing Sludge Using X-ray Tomography - 20042

One of the current primary concerns within the British nuclear community is the decommissioning of legacy storage ponds in Sellafield Cumbria, where nuclear fuel cladding material (a Mg-Al alloy) resides along with fuel metallic swarf. Corrosion of the immersed metallic elements, which has been occurring over the storage period, has resulted in the formation of what is commonly known as Corroded Magnox Sludge. The behaviour of uranium metal within this particular environment and, more significantly, the identity of the corrosion products that may have formed is currently unknown. The present study attempts to shed some light on these aspects by investigating simplified surrogate systems, mimicking storage ponds. (authors)

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FY2022 Filter Test for TRU Waste Drum Prototype Unit

Continuing last year’s (fiscal year 2021) work, a prototype instrument and an NPI-6 Integrated Work Document (IWD) were developed to assess the functionality of filters on transuranic waste containers (commonly called 55 Gallon ring-top drums) without requiring the removal of the drum lid. The purpose of this work is to determine the air flow and pressure characteristics associated with filter clogging, filter pressure drop at a fixed flow rate, and leakage around the lid seal. The FY22 objectives included: (A) Development of prototype device, (B) Drafting an IWD document, (C) Defining a filter clogging parameter, (D) Assessing filter damage due to over-pressure events, and (E) A path forward to obtain approval of the system safety filters in compliance with P101-16 Industrial Ventilation – non HVACR (LANL 2022).

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Techno-economic feasibility of borehole thermal energy storage system connected to geothermal heat pumps for seasonal heating load of two buildings in Fairbanks, Alaska

Borehole thermal energy storage (BTES) is an effective solution for managing imbalanced heating and cooling loads in cold regions. This study evaluated the long-term feasibility of a BTES system in the Fairbanks area, Alaska, through building energy modeling, resource characterization, and numerical modeling. The system was designed to store waste heat from a nearby coal power plant during summer and provide thermal energy during winter to geothermal heat pumps supplying heating loads in two buildings. Heating load profiles were modeled for the buildings using EnergyPlus, and the results indicated the annual heating load was 5.6 times greater than the cooling load. 40 borehole heat exchangers were pre-designed approximately 100 m away from the two buildings in terms of land availability and regulatorily optimized depth. The 20-year performance of the designed BTES system under two operational scenarios—one with a 5-year preheating period and one without—was numerically modeled using subsurface temperature and properties characterized through the literature review and thermal response tests. Both scenarios demonstrated that the BTES has the capacity to fully cover the heating loads in the two buildings throughout the 20-year lifetime. Production temperatures at central wells were 33 % higher on average than at outer wells in both scenarios. The 5-year preheating period increased subsurface and extraction temperatures, and correspondingly annual average and total thermal energy production was higher for 8 years than in the scenario without the preheating period. These results highlight the long-term reliability and sustainability of the BTES system in meeting heating demands over its lifetime, with the preheating period offering potential performance improvements. Implementing the BTES system in cold regions with high heating demand, such as Fairbanks, Alaska, could provide a long-term, sustainable energy solution for managing imbalanced heating and cooling loads.

15 GEOTHERMAL ENERGY↗