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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 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Analysis of Tank 38H (HTF-38-24-53, -56) and Tank 43H (HTF-43-24-54, -55) Samples for Support of the Enrichment Control and Corrosion Control Programs

Savannah River National Laboratory analyzed samples from Tank 38H and Tank 43H to support the Enrichment Control Program (ECP) and Corrosion Control Program (CCP). The results indicate the concentrations of most soluble species in the Tank 38H surface sample increased from the previous Tank 38H surface sample. The current Tank 38H subsurface sample shows similar Na, free hydroxide, and anions in comparison to the previous subsurface sample. However, the 38H subsurface sample shows lower concentrations of Al, Ca, Fe, Mn, and Si in comparison to the previous Tank 38H subsurface sample. Measurement of the wt.% insoluble solids in the Tank 38H subsurface sample and associated uncertainty analysis indicates that the calculated average wt.% insoluble solids is 0.45 ± 0.75 wt.%. Significant differences in the concentrations of major components between the Tank 38H surface and subsurface samples indicate significant stratification of solution species between these two locations within Tank 38H.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2025

Analysis of Tank 38H (HTF-38-25-36, -32) and Tank 43H (HTF-43-25-33, -35) Samples for Support of the Enrichment Control and Corrosion Control Programs

Savannah River National Laboratory (SRNL) analyzed samples from Tank 38H and Tank 43H to support the Enrichment Control Program (ECP) and Corrosion Control Program (CCP). The results indicate the concentrations of most soluble species in the Tank 38H surface sample are similar to the previous Tank 38H surface sample. The current Tank 38H subsurface sample shows similar Na, free hydroxide, and anions in comparison to the previous subsurface sample. The current Tank 38H subsurface sample appears brown in color. Measurement of the wt.% insoluble solids in the Tank 38H subsurface sample and associated uncertainty analysis indicates that the calculated average wt.% insoluble solids is 5.5 ± 3.6 wt.%. Significant differences in the concentrations of major components between the Tank 38H surface and subsurface samples indicate stratification of solution species between these two locations within the Tank 38H. The current Tank 43H surface sample is ~ 10% diluted versus the previous Tank 43H surface sample and the Tank 43H subsurface sample is similar in composition to the previous Tank 43H subsurface sample. Information provided by SRMC on tank additions since the last ECP sampling indicates that a total of about 4,062 gallons of water was added to Tank 43H. This addition could account for the observed relatively small dilution of ~ 10% in the Tank 43H surface sample. Similar solution compositions measured in the current Tank 43H surface and subsurface samples indicate a minimal stratification within the tank.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2026

Analysis of Tank 38H (HTF-38-26-16, -17), Tank 43H (HTF 43-26-18, -19) and Tank 22 (HTF-22-26-20, -21) Samples for Support of the Enrichment Control and Corrosion Control Programs

Savannah River National Laboratory (SRNL) analyzed samples from Tank 38H, Tank 43H and Tank 22H to support the Enrichment Control Program (ECP) and Corrosion Control Program (CCP). The results indicate the concentrations of most soluble species in the Tank 38H surface sample are ~ 76% of the concentrations in the previous Tank 38H surface sample. The current Tank 38H subsurface sample is a clear solution with soluble species that are ~ 70% of the concentrations in the previous Tank 38H subsurface. Significant differences in the concentrations of major components between the current Tank 38H surface and subsurface samples indicate stratification of solution species between these two locations within Tank 38H.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2024

Interactions between phosphate and arsenic in iron/biochar-treated groundwater: Corrosion control insights from column experiments

An increasing number of studies have reported the coexistence of arsenic (As) and phosphorus at high concentrations in groundwater, which threatens human health and increases the complexity of groundwater remediation. However, limited work has been done regarding As interception in the presence of phosphate in flowing systems. In this study, a series of experiments were conducted to evaluate the interactions between phosphate and As during As removal by iron (Fe)-based biochar (FeBC). The addition of phosphate promoted As removal by FeBC in the batch and column experiments. X-ray absorption near edge structure (XANES) analysis provided evidence of simultaneous oxidation and reduction of trivalent arsenic in the FeBC column experiment, accompanied by corrosive Fe oxidation. However, the addition of phosphate enhanced As stabilization, attributed to the As-incorporated Fe-Ca-phosphates precipitates. The involvement of phosphate decelerated the Fe corrosion and the formation of secondary minerals in the column, mediating the risk of passivation and clogging. The As retained by Fe-Ca-phosphate precipitates was more readily oxidized, resulting in higher proportions of pentavalent arsenic. In conclusion, the results of this work identify the corrosion control and sustained-release roles of phosphate in FeBC application, informing the perspective of FeBC in As-contaminated groundwater remediation and providing new insights into the interactions between phosphate and As.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Integrity Monitoring and Assessment, Prediction, Repair, and Corrosion Control of the Hanford Storage Tanks — 25213

BACKGROUND AND PROJECT TASKS Proposed work addresses focus area 1: Waste Retrieval, Transport and Closure, with particular focus on increasing volume available for tank storage 1) Refurbish/fortify existing double shell storage tanks (Tank Refurbish – Polymer Grout) 2) Robust monitoring tools for internal corrosion (Integrity Monitoring -Reference Electrodes) 3) Mitigate external corrosion (Degradation Prevention - Cathodic Protection) 4) Determine viability of constructing new tanks, and storage room creation by way of evaporation (Cost Benefit Analysis)

Shukla, Pavan K. [Savannah River National Laborato↗
DOE OSTI2026

Update on Integrity Monitoring, Prediction and Assessment, Corrosion Control, and Repair of the Hanford Storage Tanks

DOE has launched a multi-year research program with the focus of preserving and increasing available volume for waste storage at Hanford. The long-term availability and operability of the Hanford Double Shell Tanks (DST) is critical to the completion of the Hanford mission. Maintaining the integrity of the tank will involve having a technology for repair or refurbishment of a DST should the tank function be compromised by degradation, monitoring the tank for indications of accelerated degradation, developing a means for mitigating accelerated degradation, and evaluating options for increasing the storage capacity in the tank farm without constructing new tanks. The project work was started in the middle of 2024; significant progress has been made in the following four areas: (i) tank refurbishment using a high performance grout and an epoxy sealant layer system, (ii) developing a chemically and radiologically stable reference electrode, (iii) designing and implementing a cathodic protection system to mitigate underside corrosion of DST secondary shells, and (iv) exploring evaporation to increase waste storage capacity.

Shukla, Pavan [Savannah River National Laboratory ↗
DOE OSTI2025

Integrity Monitoring, Prediction and Assessment, Corrosion Control, and Repair of the Hanford Storage Tanks – 25213

The Hanford Nuclear Reservation site contains approximately 211 million liters of radioactive and chemically hazardous waste arising from nuclear weapons production, beginning with World War II, and continuing through the Cold War [1]. The waste is stored in 177 carbon-steel underground storage tanks, of which 149 are single-shell tanks (SSTs) and the remaining are double-shell tanks (DSTs). The mission of an ongoing River Protection Project is to retrieve the waste from the underground storage tanks and then treat and immobilize (i.e., vitrify) it for disposal. Waste from the older SSTs is being progressively retrieved into the newer DSTs for storage pending treatment, immobilization, and disposal. Figure 1 depicts a typical DST design [2]. The tank is approximately 23 m in diameter and 9 m high and has a domed structure and has a capacity of 4000 m3. The tank wall and floor vary in thickness between approximately 10 mm and 25 mm depending on location. The thicker wall sections are near the curved transition between the tank wall and the floor, while the thinner sections are located near the top of the tank wall. The tank floor thickness varies from 25 mm at the tank center to 10 mm near the tank wall. The tanks were constructed of either ASTM A516 Grade 65 or ASTM A537 Class 1 carbon steel and were post-weld heat treated to reduce the risk of SCC.

Shukla, Pavan K. [Savannah River National Laborato↗
DOE OSTI2024

Development and Assessment of Deployed Sensors and Technologies Supporting Molten Salt Loop Operations

During FY24, Argonne conducted a variety of activities to develop and assess new monitoring and control technologies towards enabling long-duration operations of molten salt reactor systems. The first objective of the work completed this year was to deploy technologies capable of reliably and rapidly monitoring the operational health of a molten salt loop. To achieve this, the project focused on specific tasks, including: (1) electroanalytical technique development for use in deployed sensors, and (2) operations of sensors on the Facility to Alleviate Salt Technology Risks (FASTR) loop at Oak Ridge National Laboratory. The second objective of the work this year focused on creating a pumped actinide flow loop to enable long-duration salt chemistry and corrosion studies using uranium-bearing fuel salts. Toward that end, we designed and procured a loop capable of being installed into a radiological glovebox at Argonne. A corrosion control system was also designed for integration into this loop. These combined systems will enable the feasibility of corrosion control and management systems to be investigated with complex chloride fuel salt mixtures.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2025

A Review of Tank 48H Treatment of Tetraphenylborate with Permanganate

Tank 48H contains roughly 270,000 gallons of radioactive waste material. The waste stored in this tank was to be processed in multiple stages utilizing facilities at the Savannah River Site (SRS) almost 30 years ago. The In-Tank Precipitation Process (ITP) was initiated in Tank 48H, which precipitated highly radioactive cesium-137 using sodium tetraphenylborate (NaTPB). While the process succeeded in precipitating the Cs, Sr, and other actinides, it also generated an unexpectedly large amount of benzene. The evolved benzene created a safety concern and made the waste incompatible with further downstream processing. This halted the ITP, and a new method of treatment was required to continue processing the legacy waste contained in Tank 48H. A myriad of treatment options have been proposed with multiple teams of researchers assembled to work on this highly complex issue over the last few decades. This review investigated one potentially viable treatment option, in-tank oxidation with sodium permanganate. Permanganate has been well known in literature as a strong oxidizing agent for organic compounds, as well as being utilized at the Savannah River Site (SRS) in other processes. A small number of studies have been conducted utilizing waste simulants to evaluate the use of permanganate as an oxidant for tetraphenylborate (TPB). A search of the literature and data from these studies indicates that permanganate could be a viable treatment for destruction of TPB in Tank 48H. While the scoping studies had a small number of individual experiments and nonideal conditions, the permanganate decomposed up to 90% of the TPB. A free hydroxide concentration above 1.0 M is required for tank corrosion control. Simulant studies indicate no decrease in TPB decomposition by permanganate until pH 14. The simulant studies show an increase in TPB decomposition as the temperature of the solution is increased to 40 °C. The post-reaction analysis of previous simulant tests did not look at all of the organic degradation products. Investigations into what these organic products are and in what quantity will help guide determinations as to whether the downstream processing facilities are able to handle the material that will be generated. Study on the time frame for the reaction between permanganate and TPB should be investigated as the literature reports only extend out to two weeks reaction time. The permanganate treatment conditions indicate no corrosion control concerns and a longer timescale reaction may be needed for in-tank treatment. In addition, further study would be useful to identify a lower boundary condition for the ratio of TPB and oxidant. The simulant tests applied large excesses of permanganate, and this may be unnecessary. The size constraint of the tank means that there will be practical limitations on the amount of sodium permanganate that can be added to the tank. The amount of permanganate should be minimized as much as possible while still ensuring decomposition of the TPB to minimize the amount of manganese dioxide solids generated.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2024

Design and Materials of Reference Electrodes for Radioactive Waste Tank Service – A Literature Review

The Hanford site stores approximately 55 million gallons of radioactive and chemically hazardous wastes from the production of weapons materials. The wastes are stored in 177 underground, carbon steel storage tanks, 149 of these are single shell tanks (SSTs) and 28 of these are double shell tanks (DSTs). The DSTs provide critical retrieval and interim storage before the waste is vitrified in the Waste Treatment and Isolation Plant (WTP). The DSTs have been in service for 38 to 56 years and current plans indicate that WTP operations will be completed in 2075. Thus, the tanks will need to remain in service far beyond the initial 40-year life expectancy. For life extension of the tanks, effective corrosion control practices must remain in force. This effort includes direct measurements of the extent of corrosion (e.g., ultrasonic measurements and corrosion coupons) and electrochemical processes (e.g., linear polarization measurements).

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2025

Development of a Robust Reference Electrode in Aggressive Chemical and Radiation Environments in the Hanford Waste Tanks

The Hanford site stores more than 200 million liters of radioactive and chemically hazardous wastes from the production of weapons materials. The wastes are stored in 177 underground carbon-steel storage tanks, separated between 149 single shell tanks (SSTs) and 28 double shell tanks (DSTs). The DSTs provide critical retrieval and interim storage before the waste is vitrified in the Waste Treatment and Isolation Plant (WTP). The tanks will need to remain in-service far beyond the initial 40-year design life, and effective corrosion control practices must remain in force to extend the tanks’ lifespans. This effort includes direct measurements of corrosion rate (e.g., ultrasonic measurements and corrosion coupons) and electrochemical processes (e.g., linear polarization measurements and open circuit potential measurements). The Hanford site began monitoring the corrosion potential in select DSTs in 2008. Of the 45 reference electrodes that have been installed, 29 have failed and 6 others provided unreliable results. DOE-EM is supporting a 3-year program to develop a chemical and radiation resistant reference electrode for application in the Hanford tanks. The first year of the program focused on understanding the failure mechanism for the reference electrodes and identification of candidate construction materials that would mitigate degradation of the electrodes in the waste environment. During the second year of the program, the objectives were to: 1) test candidate materials under simulated waste conditions, 2) design components that will extend the service life of the electrode, 3) fabricate materials for prototype reference electrodes, and 4) assemble prototype reference electrodes for accelerated testing. The reference electrode is constructed of four principal parts: 1) junction, 2) casing, 3) inner chamber backfill materials, and 4) the sensing wire. Principally, improvements of the junction, casing, and inner chamber backfill materials are being pursued. The junction material at the interface between the waste and the inner chamber of the reference electrode was identified as a critical component in the failure of the reference electrodes. Nine candidate replacement junction materials were tested under simulated waste conditions to evaluate permeation rate. These materials included a variety of polymeric and ceramic materials, some of which were 3-D printed. Thus far, porous polyvinylidene fluoride materials have performed satisfactorily and are being considered for prototype development. The commercial electrode casing materials in general have performed well. Additionally, 3-D printing of chemically and mechanically stable materials is being investigated as a means for further improvement in fabrication consistency. SRNL has also investigated altering the reference electrode design to extend the service life. The new design of the interior of the reference electrode casing creates a longer, more tortuous path between the junction material and the electrode sensing wire. A finite element model was used to optimize the design without adversely impacting the circuit resistance of the electrode during the measurements, thus preserving the measurement accuracy while enhancing the service life. The inner chamber back fill materials are also critical to the performance of the reference electrode. Materials that are resistant to intruding tank waste and provide a conductive path to the sensing wire were investigated. Gel and powder materials that are interspersed with a conductive chloride bearing material were tested for their influence on diffusion and electrode resistance. All the investigated materials and components will be assembled, with collaboration from commercial vendors, to fabricate the initial prototypes. Accelerated testing of the prototypes will be initiated in Year 2 of the program and will be completed in Year 3. A recommendation on the materials of construction and the design of the new robust reference electrode will be presented to the Hanford tank farm facility.

Sykes, Kiana [Savannah River National Laboratory (↗
DOE OSTI2025

STATISTICAL ANALYSIS OF IN-SERVICE ULTRASONIC INSPECTION DATA OF WASTE TANKS AT THE SAVANNAH RIVER Site-25021

CONCLUSIONS AND RECOMMENDATIONS •“There is no evidence of pit depth growth over the last 15-years demonstrating the effectiveness of the corrosion control program. •“Incipient pits” are not growing and are likely pre-service pits. • No need to continue measuring these tiny pits. However, due to the random nature of pit initiation and the potentially accelerated growth of a pit, periodic monitoring for pit growth is prudent. 1. No reportable pits were identified. All identified pits are far less than the reportable depth of 25% of the nominal wall thickness. 2. No cracking was identified. 3. There is no evidence that active, systemic corrosion has occurred in Tank 29 during its 38-year service history as of 2009.

Harris, Stephen P. [Savannah River National Labora↗
DOE OSTI2024

Sludge Batch 11 Assembly: Tank 35

Savannah River Mission Completion Nuclear Safety and Engineering Integration (SRMC-E) has requested that Savannah River National Laboratory (SRNL) perform Tank 35 characterization analyses in support of Sludge Batch 11 (SB11) assembly. Two Tank 35 samples were delivered to SRNL and composited into a single sample in April 2023. The composite sample was analyzed for the following: density, weight percent solids, chemical composition, radionuclides, supernate corrosion control tests, and x-ray diffraction for burkeite, gibbsite, and boehmite.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2024

Sludge Batch 11 Assembly: Tank 26 (Rev.1)

Savannah River Mission Completion Nuclear Safety and Engineering Integration (SRMC-E) has requested that Savannah River National Laboratory (SRNL) perform Tank 26 characterization analyses in support of Sludge Batch 11 (SB11) assembly. This report provides important characterization of the slurry in Tank 26 prior to transfer from Tank 26 to Tank 51 that confirms the transfer is "Low Rem" and ensures the sludge concurs with the estimated transfer mass for the SB11 recipe. Two Tank 26 samples were delivered to SRNL and composited into a single sample in September 2023. The composite sample was analyzed for the following: density, weight percent solids, chemical composition, radionuclides, supernate corrosion control tests, and x-ray diffraction for burkeite, gibbsite, and boehmite. The slurry was also evaluated for sulfate washing behavior in order to provide knowledge on insoluble sulfate dissolution during Tank 51 sludge washing similar to a previous washing study performed in 2019. The Tank 26 sample results are consistent with and representative of PUREX sludge and the prior usage of Tank 26 as a feed tank for the 1F and 2F Evaporators.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2024

Sludge Batch 11 Assembly: Tank 51

Savannah River Mission Completion (SRMC) Nuclear Safety and Engineering Integration has requested that Savannah River National Laboratory (SRNL) perform Tank 51 characterization analyses in support of Sludge Batch 11 (SB11) assembly. This report provides important characterization of the slurry in Tank 51 after transfers from Tank 22, Tank 35, and Tank 13 (post Tank 15 to Tank 13 transfer) to Tank 51 that demonstrates the sludge concurs with the estimated transfer mass for the SB11 recipe. A total of 3 sets of Tank 51 samples were delivered to SRNL from March 2023 to February 2024. The composite sample was analyzed for the following: density, weight percent solids, chemical composition, radionuclides, and supernate corrosion control analyses. The results of the Tank 51 samples are consistent with and representative of expected sludge projections for Sludge Batch 11.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2025

Steady state radiolysis–polyhalide accumulation products [Poster]

The study of steady-state radiolysis of polyhalides is crucial as it simulates the prolonged radiation exposure that materials (e.g., alloys, molten salts) experience in reactor environments. This research provides valuable insights into the long-term effects on material properties, chemical stability, and structural integrity. It is closely linked with fundamental radiation chemistry, which aids in predicting the chemical behavior of accumulation products. Understanding the initial speciation, yield, and chemical evolution of radiolysis products is essential for managing material degradation, controlling corrosion, and ensuring reactor safety.

36 - MATERIALS SCIENCE↗