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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 577 records · Page 32
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Flow battery cleansing cycle to maintain electrolyte health and system performance

A method of cleansing a redox flow battery system may include operating the redox flow battery system in a charge, discharge, or idle mode, and responsive to a redox flow battery capacity being less than a threshold battery capacity, mixing the positive electrolyte with the negative electrolyte. In this way, battery capacity degradation following cyclic charging and discharging of the redox flow battery system can be substantially reduced.

Song, Yang↗
DOE OSTI2015

The role of independent monitoring in maintaining community support through a radiological incident - a WIPP case study - 15107

The Waste Isolation Pilot Plant (WIPP) is a U.S. Department of Energy (DOE) waste repository for the permanent disposal of defense transuranic (TRU) wastes. The repository is mined in the Salado Formation, a bedded salt formation of the Permian era, approximately 655 m (2150 ft.) below land surface. Located near Carlsbad, New Mexico, the WIPP facility is the world's first deep geological disposal facility licensed to accept TRU waste. Environmental monitoring is a key component in the development and operation of any nuclear facility. Well after the WIPP facility had been sited and constructed, but before repository operations began, DOE and local community leaders recognized the value of having an independent environmental monitoring program in addition to the self-monitoring program required by regulation. An independent monitoring organization, the Carlsbad Environmental Monitoring and Research Center (CEMRC) was created by New Mexico State University at its Carlsbad campus. After almost fifteen years of successful waste disposal operations, the first airborne radiation was accidentally released from the WIPP and detected beyond the site boundary on February 14, 2014. The accident released moderate levels of radioactivity into the underground air. A small but measurable amount of radioactivity also escaped to the surface and was detected beyond the site's inner boundary. The results were reported to the public as they were obtained and verified. Releases were low and localized, and no radiation-related health effects among local workers or the public would be expected. CEMRC's independence and its extensive monitoring program played a crucial role in timely informing the local populations on the levels and types of radiation released from the WIPP. CEMRC also helped eliminate unnecessary concern surrounding fear of radiation by engaging local populations through news releases and presentations at 'town hall' meetings sponsored by the Mayor's Office and the Department of Energy. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Maintaining department of energy (DOE) waste disposition pathways in today's uncertain budgetary environment - 15129

For many years the Department of Energy (DOE) and its prime contractors have worked collaboratively with commercial waste transportation, treatment, and disposal providers to develop and implement outlets for the efficient management and disposition of radioactive wastes, particularly 'no-path-forward' or 'difficult-to-treat' wastes. Both the DOE and commercial providers have made substantial investments to develop capabilities and infrastructure to address these wastes and both have benefited from this collaboration. For example, DOE realized significant cost savings and avoidances when a commercial facility became available that allowed closure of the TSCA incinerator in Oak Ridge or when commercial capabilities were expanded that precluded the need to build a new Hanford M-91 waste treatment facility, estimated at $540 million for design, permitting, and construction. In addition, expanded capabilities developed at commercial facilities ensured a known, if not guaranteed, source for managing waste and improving efficiencies for wastes which previously had no viable disposition outlet or that required extended schedules and cost for completion. Such wastes include sodium- and mercury-bearing wastes, classified shapes, or many forms of suspect transuranic (TRU) wastes. (authors)

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

Remote Geophysical Logging at the Hanford Single-Shell Tank Farms: Maintaining Efficiency and Reducing Personnel Hazards - 16190

Vadose zone characterization around groups of underground waste storage tanks (known as tank farms) at the US DOE Hanford Site in Washington State is conducted to assess the presence and extent of manmade gamma-ray emitting radionuclides. Boreholes around the tanks are characterized using a high-resolution spectral gamma logging system (SGLS). In the past, logging operations required workers to remain inside the tank farm boundary during data acquisition. This approach was effective; however, personnel were at risk of exposure to potential radiological hazards, chemical hazards, and/or vapor releases that can be associated with the tank farm environment. Limitations associated with this work environment necessitated a new approach in order to decrease the amount of time personnel spent in the farm without affecting work productivity and efficiency. In order to accomplish this, a new remote logging cable support (RLCS) was developed and implemented which effectively removed workers from the hazards associated with the tank farm environment. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2023

Systems and methods for maintaining structures

A motorized apparatus includes a body assembly and a maintenance device mounted to the body assembly. The maintenance device is configured to perform a service operation on a surface. The maintenance device extends from the body assembly at an angle. The motorized apparatus also includes a plurality of leg assemblies coupled to the body assembly and configured to support the body assembly and the maintenance device at a distance from the surface. The motorized apparatus further includes at least one actuator assembly coupled to the plurality of leg assemblies and configured to independently actuate each leg assembly of the plurality of leg assemblies. The at least one actuator assembly is configured to receive instructions related to a position of the maintenance device and actuate the plurality of leg assemblies to adjust an orientation of the body assembly and the maintenance device relative to the surface.

Duncan, Alexander Kyle↗
DOE OSTI2020

Panel Session 35: Strategies and Successes in Increasing Efficiency and Reducing Cost to Accelerate Work While Maintaining Operational Excellence (R1.5)

This panel focused on results-based project execution and ways to improve the effectiveness of large radioactive clean-up site operations while increasing efficiency and reducing cost. Panelists discussed best practices and lessons learned from their sites and projects as they work within budgetary, resource and technological constraints. Panelist with presentations: CNS Journey (Morgan Smith)

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

Improved Safety Injection Flow Map Associated with Target RCS Depressurization to Maintain Core Coolability of OPR1000

In Korea, Severe Accident Management Guidance (SAMG) for Optimized Power Reactor (OPR1000) has been developed through the research results related to the WOG SAMG, in which the operation phase shifts from the Emergency Operation Procedure (EOP) to the SAMG when the Core Exit Temperature (CET) reaches 923 K. Among 7 mitigation strategies envisioned, the third management strategy, injecting coolant into Reactor Coolant System (RCS) by depressurizing the RCS is one of the key strategies to fortify the in-vessel retention capability. As an aid to such mitigation strategy, a safety injection (SI) flow map has been developed by Lee et al. for predicting required flow rate associated with target RCS depressurization to recover in-vessel coolability. The mechanistic SI flow map used the CET increase rate and core water level decrease rate obtained from MELCOR code simulation. It should be noted that during the severe accident, the total heat generated is sum of the decay heat and the oxidation heat. Thus, it is necessary to consider additional heat sources by oxidation reaction between cladding, structure, control rod, and hot steam prior to the injection of coolant. It was believed that the SI model estimated required flow rate rather conservatively by considering the expected amount decay heat and the accumulated heat in the core based on the RCS pressure. However, it was confirmed that the SI model developed by Lee et al. could not represent the total heat removal especially since start of oxidation. Under transient conditions, the heat sources accumulated in the heat structures (fuel, cladding, supporting structures) should be embarked in the model for accurate contribution of the total heat source to the required flow rate. Therefore, the objective of this study is to improve the previous SI flow map predicting the injection flow rate associated with target RCS depressurization to satisfy the in-vessel coolability during severe accidents. Additional terms were developed to reflect accurate heat accumulating and included in the existing model. Resulting SI flow map includes the target RCS depressurization, which enables discharge of the required flow rate by utilizing the flow rate-pressure curve with operation of two high pressure safety injections (HPSIs). Also recent MELCOR simulation result of a postulated steam generator tube rupture (SGTR) accident verified the accuracy of the improved map.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2026

Data for The Value of Reversible Carbon Storage in a Zero-Emissions World

Atmospheric carbon dioxide removal (CDR) is required to stabilize global temperature. CDR can be achieved via ecosystem-based approaches that are cost-effective but reversible (e.g., soil and forest management) or by more durable but expensive approaches (e.g., direct air capture coupled with geologic storage). Here, we examine trade-offs between these approaches, focusing on timing, climate impacts, and cost. We simulated reversible carbon accrual for a range of CDR contract structures using a general minimalist model of ecosystem carbon cycling, and parameterized it to simulate US agricultural soil management─specifically cover cropping─as a case study. We then quantified the resulting impact on atmospheric carbon and global temperature using a climate model emulator. We find that maintaining a patchwork of reversible CDR projects by replacing lapsed projects with new projects can reduce warming by 22–195 μ°C in 2100 and that the magnitude of this cooling effect depends on how effectively the patchwork is maintained. Long-term maintenance of reversible CDR projects requires institutional stability that cannot be guaranteed over multiple decades. Consequently, effective CDR ultimately requires replacing reversible projects with durable projects. To address this problem, we modeled the cost of replacing reversible agricultural soil CDR with geologic CDR. We found that using reversible CDR as a bridge to durable CDR is potentially more cost-effective as a global cooling strategy (0.20–0.81 billion USD per μ°C avoided) than perpetual maintenance of reversible CDR (0.32–1.31 billion USD per μ°C avoided) or an immediate transition to durable CDR (1.37–2.19 billion USD per μ°C avoided). However, we emphasize that institutional commitments to maintain reversible CDR projects cannot be guaranteed. Reliance on reversible CDR as a bridge to durable CDR therefore carries an unknown amount of risk and will only function if efforts to maintain reversible CDR are robust.

Carbon↗
DOE OSTI2015

Socially Driven HVAC Optimization Federal Building and US Courthouse Phoenix, Arizona

Under many circumstances in facilities management, keeping occupants comfortable and saving energy are diametrically opposed. To stay cool in summer and warm in winter requires energy to maintain indoor temperatures. If energy is saved by allowing indoor temperatures to get warmer in the summer or colder in winter, occupants’ comfort levels decrease. There is great potential to reduce costs and maintain occupant comfort if a system existed that could break this diametric opposition. The comfort of building occupants in today’s facilities is controlled by maintaining a given space temperature through the use of a thermostat. These devices operate in a very simple manner in which they are set to maintain a certain constant space temperature range. If the occupant is too hot or cold, he or she writes a work order for facility maintenance staff to adjust the thermostat to a new constant temperature range. This feedback cycle is repeated as needed to avoid generating complaints of too hot/cold from the occupants. This system has two areas in which it can be improved. First, there is the labor cost associated with a facilities maintenance person having to respond to each request when an occupant is uncomfortable. Person-hours are spent receiving the work order and adjusting space thermostats to a level that, hopefully, will allow the occupant to be comfortable. Second, the space temperature is maintained within a constant range, with no effort being made to finetune the space temperature to a setting that conserves energy while maintaining occupant comfort. Occupant comfort is based upon many more factors than just the space temperature. When other factors are taken into account, there is potential to save energy while maintaining that comfort level.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗