Pilot Deployment and Testing of Exoskeleton Devices at the Hanford Site .
Abstract not provided.
Wheeler, Jason↗
Engineering topics
Boomer, Kayle
Publications and source records attributed to Boomer, Kayle.
Technology Development for Under Tank Inspection of Double-Shell Tanks - 20045
The Department of Energy (DOE) Office of River Protection (DOE-ORP) is responsible for management and cleanup of the tank farms located at the Hanford Site. Nuclear waste at Hanford is stored in 149 single-shell tanks (SSTs) and 27 double-shell tanks (DSTs). The vast majority of the liquid radioactive waste is stored in the DSTs. The 27 DSTs, located in six tank farms, were constructed from 1967 to 1986 and, compared to the SSTs, provide greatly improved protection from leakage and better accessibility for inspection. The DSTs and ancillary equipment are expected to exceed their design life before their waste is removed and sent to the Waste Treatment and Immobilization Plant. The DST Integrity Project (DSTIP) must ensure that the DST system can meet the River Protection Project mission goals. This paper provides a programmatic overview of the DSTIP with a focus on development of under-tank inspection technologies. Currently, two categories of nondestructive examination (NDE) techniques for DSTs are implemented on the Hanford site: (1) surface (SNDE) and (2) volumetric (VNDE). Further discussion on current inspection techniques is provided in this paper. The technology development approach for advanced VNDE techniques will also be generally discussed as a precursor for another more detailed WM2020 paper and presentation by PNNL. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Mechanical Waste Gathering System (MWGS), Alternate Retrieval of Hanford Tank Waste - 19188
Hanford has 149 underground single shell tanks; of which several have known or suspected leak sites. Sluicing with large volumes of solution in compromised leaking tanks is not desirable due to the risk of environmental release. To address the complex retrieval of hardpan nuclear waste in Hanford's single shell tanks, a Mechanical Waste Gathering System is being developed and tested, which breaks up the waste and moves it to the surfaces without the introduction of liquid to the tank bottom. To improve the removal of hardpan tank waste, WRPS has leveraged industry knowledge and previous experience to identify a solution. This technology will provide another option for the technology toolbox at Hanford. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Progress on Advancing Robotic Ultrasonic Volumetric Inspection Technology for Hanford Under-tank Inspection - 19474
The Hanford River Protection Project is reliant on safe interim storage of high-level waste at the Hanford site and will continue to depend on it until the waste has been treated and vitrified by the Hanford Waste Treatment and Immobilization Plant (WTP). The Hanford double-shell tanks (DSTs) have provided interim storage since the DSTs were put into service (1971 - 1986) and the RPP will continue to rely on their service until least 2050, at which time the 27 in-service DSTs will be 14-54 years beyond their original design lives. As the DSTs continue to age and be operated beyond design life, reliable leak integrity assessments of primary tanks and secondary liners will become increasingly important in order to provide situational awareness to tank operations personnel and to support risk-informed decisions on the selection of DSTs as waste feed staging tanks and the order and timing of future DST refurbishment or, alternatively, DST retrieval sequence. This paper summarizes progress made in fiscal year (FY) 2018 on the engineering of a robotic air-slot volumetric inspection system (RAVIS) that is designed to perform ultrasonic (volumetric) leak integrity inspections of physically inaccessible primary tank bottom plates and welds. Leak integrity inspections performed with the RAVIS will supplement today's primary tank leak integrity inspections, which are currently limited to physically accessible sidewall plates and welds. The RAVIS will be deployed into air slots of the insulating concrete (refractory) pad beneath the primary tanks and use its ultrasonic guided wave phased-array (GWPA) sensor to electronically steer an ultrasonic beam 360-degrees around the sensor to volumetrically examine adjacent carbon steel plates and welds covered by refractory pad material. Deployments of RAVIS down multiple air-slots will be performed to determine which regions of a tank bottom have sound leak integrity or which regions are in need of future wall thickness restoration or weld repair due to pitting corrosion, general corrosion, or heat/stress-induced cracks. The initial RAVIS design and the flaw detection test results for the first air-slot GWPA sensor that was designed to fit inside the air-slots will be presented in this paper. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Waste Chemistry Envelope for the Determination of Pitting Corrosion Susceptibility - 19554
Liquid radioactive wastes at the Hanford and Savannah River sites are stored in large underground carbon steel tanks. The high-level wastes are processed in several of the tanks and then transferred by piping to other site facilities for further processing before they are stabilized in a vitrified or grout waste form. Based on waste removal and processing schedules, many of the tanks, will be required to be in service for times exceeding the initial intended life (i.e., greater than 60 years). Until the waste is removed from storage, transferred, and processed, the materials and structures of the tanks must maintain a confinement function by providing a barrier to the environment and by maintaining acceptable structural stability during design basis events, which include loadings from both normal service and abnormal (e.g., earthquake) conditions. Administrative programs are in place to mitigate potential corrosion mechanisms and thereby maintain the structural and leak integrity functions of these waste tanks throughout their intended service life. Waste chemistry and temperature control are the means by which corrosion degradation of the waste tanks is minimized. Chemistry controls are based on in-situ coupon tests, waste tank experience, and laboratory testing. These requirements comprise the technical standards for corrosion control. The standards are utilized then as guidelines for operational procedures. The present waste chemistry controls for the Hanford DSTs were established in the 1980's in response to tank failures caused by stress corrosion cracking (SCC) at the DOE Savannah River Site (SRS). Portions of the SRS chemistry limits, which were developed at the Savannah River National Laboratory (SRNL) were coupled with corrosion testing results from Pacific Northwest National Laboratories (PNNL) and adopted for corrosion control of the double-shell tank (DST) waste at the Hanford Site. Since that time, the temperatures of the waste in the DSTs have decreased to less than 50 deg. C in most cases as the radioactive material has decayed. As a consequence, new chemistry controls were formulated for SCC in 2010. This testing however, did not address that potential for pitting in the supernatant and at the liquid-air interface. Indeed, initial tests indicated that the inhibitor requirements for SCC would be insufficient for the prevention of pitting. In addition to lower waste temperatures, future retrieval and process changes may impact the DST waste chemistry. Initial projections suggest that the waste chemistry of the DSTs may shift to a broader range of pH and higher aggressive anion concentrations (e.g., chloride, sulfate, etc.) than the wastes that are presently stored. Additionally, processes within the vitrification facility may result in streams that are returned to the tank farm for evaporation. These streams may also contain high concentrations of aggressive species. SRNL investigated the propensity for pitting of the carbon steel waste tanks at current and projected DST waste chemistries. A statistically designed series of tests provided a pitting factor that relates the ratio of the inhibitor species to the aggressive species and the probability of observing pitting. An acceptable pitting factor was determined and was utilized for the development of a new chemistry envelope. The new chemistry envelope was compared to the envelope that was established for SCC and was determined to be bounding. Validation of the new chemistry envelope was performed via model simulations and comparison with historical experimental results and approaches to establishing chemistry envelopes. The new chemistry envelope will eventually be part of an overall assessment of the condition of the tanks and any changes made to the overall structural integrity program for the Hanford DSTs. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Hanford Under-tank Inspection with Ultrasonic Volumetric Non-destructive Examination Technology - 18470
The U.S. Department of Energy (DOE) and the Hanford Site Tank Operations Contractor Washington River Protection Solutions, LLC (WRPS) are sponsoring a non-destructive evaluation (NDE) technology development program to identify and mature volumetric (non-visual) NDE technology that will enable the examination of Hanford double-shell tank (DST) bottoms. NDE technology for Hanford under-tank examination will be made possible through technology maturation that includes adaptation of NDE sensor technology to overcome access challenges presented by tank risers and refractory pad air-slots, followed by integration with robotic delivery systems, and ultimately qualification and deployment of the inspection systems. The stages of technology maturation and the testing and evaluation required to support the process are organized under three program phases: Phase I - NDE Capability Testing: Identify and down-select NDE technologies based on flaw detection and characterization abilities only; Phase 2 - NDE Delivery System Testing: Mature promising NDE technologies to adapt transducer hardware and robotic delivery system to address access challenges; Phase 3 - Full-scale Demonstration of Integrated NDE System: Demonstrate adapted NDE technologies in a cold test platform to challenge flaw detection and navigation abilities. Phase I of the program, which was initiated and completed in FY2017, focused on completing the following five key activities: 1. Identifying a broad cross section of potentially applicable NDE volumetric inspection technologies for under-tank examination. 2. Down-selecting the broad set of NDE technologies to a set of strong candidates based on initial flaw detection performance and potential to be adapted/matured to overcome primary tank access challenges posed by access risers and/or refractory pad air-slots. 3. Evaluating the flaw detection performance of the candidate sensors through testing. 4. Using the test results to baseline sensor performance against the flaw detection requirements established for high-level waste tanks. 5. Assessing the trade-offs and vulnerabilities of the candidate sensors that would negatively impact sensor performance reliability or complicate tank inspection operations. The completion of the first three key activities satisfied the first two Phase I test objectives, which were to complete Technology Screening and Sensor Effectiveness Testing. Completion of the fourth key activity satisfied the final test objective of Phase I, which was to determine the extent to which the sensors can satisfy high-level waste tank flaw detection requirements. Sensor flaw detection performance testing yielded several suitable sensor technology options, although each has specific risks or challenges that would need to be accepted or overcome. Thus, the fifth key activity was performed to evaluate sensor risks and challenges for consideration with flaw detection performance. The Phase I evaluation outcomes will be used to support the Phase I programmatic objective, which is to identify one or more NDE sensor technologies for adaptation and maturation for the DST environment. Selection of one or more sensors will mark the culmination of Phase I of the NDE Technology Development Program and allow progression to Phase II.
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Hanford Single-Shell Tank and Double-Shell Tank Integrity Programs - 16390
Waste at Hanford is stored in 149 single-shell tanks and 28 double-shell tanks. Concerns related to aging radioactive waste storage facilities throughout the DOE complex led to Brookhaven National Laboratory (BNL) developing guidelines for structural integrity programs for tank systems. The committee of experts who developed these guidelines is commonly known as the Tank Structural Integrity Panel (TSIP). The DOE has subsequently adopted these guidelines, and requires site operators to have a program consistent with them. The Double-Shell Tank (DST) integrity is maintained with a variety of activities such as ultrasonic and visual inspections, chemistry controls, corrosion monitoring and structural analyses methods. In October 2012, Washington River Protection Solutions, LLC (WRPS) determined that the primary tank of 241-AY-102 was leaking. WRPS contracted a panel of experts from industry and academia to provide advice and recommendations for the DST Integrity Program. The panel focused on three concerns: - No Early warning - Determine why the existing DST Integrity Program did not predict a primary tank failure or provide early warning of the pending failure. - Program improvements - Recommend activities to either predict a primary tank failure or increase the probability of early warning. - Forensic recommendations - The panel provided additional recommendations regarding forensic assessment of Tank 241-AY-102 (AY-102) to facilitate a conclusion on why the leak occurred. WRPS has prepared a response to the concerns of the panel coupled with recommendations for project action to strengthen the DST Integrity Program [4]. The purpose of this DST Integrity Improvement Plan is to translate the recommendations to specific project activities that are technically and practically responsive. To improve the understanding of the Single-Shell Tank (SST) integrity, WRPS, the Department of Energy-Office of River Protection tank operations contractor, developed an enhanced Single-Shell Tank Integrity Project (SSTIP) in 2009. An expert panel on SST integrity, consisting of various subject matter experts in industry and academia, was created to provide recommendations supporting the development of the project. This panel developed 33 recommendations in four main areas of interest: structural integrity, liner degradation, leak integrity and prevention, and mitigation of contamination migration. In late 2010, seventeen of these recommendations were used to develop the basis for the M-45-10-1 Change Package for the Hanford Federal Agreement and Compliance Order, also known as the Tri-Party Agreement. The change package identified two phases of work for SST integrity. The initial phase, which was completed in 2015, was focused on efforts to envelope the integrity of the tanks. It was divided into two primary areas of investigation: structural integrity and leak integrity. If necessary, based on the outcome from the initial work, a second phase would be focused on further definition of the integrity of the tanks and liners. The two combined phases are designed to support the formal integrity assessment of the Hanford SSTs in 2018 by an Independent Qualified Registered Professional Engineer. This paper will summarize the current status of the DST and SST Integrity Programs and discuss the ongoing efforts to improve these programs. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Hanford double-shell tank testing program - 15341
The corrosion testing program and Hanford regularly tests waste chemistries to analyze threats and develop new corrosion chemistry guidelines. Over the past few years, the focus of testing has been on the threat of leaked wastes in Tank 241-AY-102 (AY-102). From the tests conducted to date, it appears that the potential waste compositions in the annulus of tank AY-102 do not show a propensity for localized corrosion or stress corrosion cracking. The threat of exterior corrosion from the liquid and moisture in the leak detection pit (LDP) is a potential concern that will continue to be evaluated in the coming year. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Progress of the enhanced Hanford single shell tank (SST) integrity project - 15497
To improve understanding of the single-shell tanks (SSTs) integrity, Washington River Protection Solutions, LLC (WRPS), the US DOE Hanford Site tank contractor, developed an enhanced Single-Shell Tank Integrity Project (SSTIP) in 2009. An expert panel on SST integrity, consisting of various subject matter experts in industry and academia, was created to provide recommendations supporting the development of the project. This panel developed 33 recommendations in four main areas of interest: structural integrity, liner degradation, leak integrity and prevention, and mitigation of contamination migration. In late 2010, seventeen of these recommendations were used to develop the basis for the M-45-10-1 Change Package for the Hanford Federal Agreement and Compliance Order, which is also known as the Tri-Party Agreement. The change package identified two phases of work for SST integrity. The initial phase was focused on efforts to envelope the integrity of the tanks. The initial phase was divided into two primary areas of investigation: structural integrity and leak integrity. If necessary, based on the outcome from the initial work, second phase would be focused on further definition of the integrity of the tanks and liners. Combined these two phases are designed to support the formal integrity assessment of the Hanford SSTs in 2018 by an Independent Qualified Registered Engineer. As the initial phase of this work completes in early 2015, this paper summarizes the project formation and status the work of the past few years associated the implementation of the Phase one recommendations. Work in the initial phase to further define the DOE's understanding of the structural integrity SSTs involved preparing a modern Analysis of Record (AOR) using finite element analysis. Structural analyses of the SSTs have been conducted since 1957, but these analyses used analog calculations, less rigorous models, or focused on individual structures. As such, an integrated understanding of all of the SSTs has not been developed to modern expectations. In support of this effort, other activities addressed the visual inspection of tank internal conditions and the collection of concrete core samples from the tanks, including a full height tank sidewall core, for analysis of current mechanics properties. The work on the liner leak integrity has examined leaks from 25 tanks with known liner failures. Individual leak assessments were developed for each tank to identify the leak cause and location and estimate historic leak rates. A common cause/failure analysis study was performed to take data from individual tanks to look for trends in the causes of failure. A separate activity is being conducted to examine the propensity for corrosion in select SSTs with aggressive waste layers. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Hanford double-shell tank extent-of-condition construction review - 15498
During routine visual inspections of Hanford double-shell waste tank 241-AY-102 (AY-102), anomalies were identified on the annulus floor which resulted in further evaluations. Following a formal leak assessment in October 2012, Washington River Protection Solutions, LLC (WRPS) determined that the primary tank of AY-102 was leaking. A formal leak assessment, documented in RPP-ASMT-53793, Tank 241-AY-102 Leak Assessment Report, identified first-of-a-kind construction difficulties and trial-and-error repairs as major contributing factors to tank failure. To determine if improvements in double-shell tank (DST) construction occurred after construction of tank AY-102, a detailed review and evaluation of historical construction records was performed for Hanford's remaining twenty-seven DSTs. Review involved research of 241 boxes of historical project documentation to better understand the condition of the Hanford DST farms, noting similarities in construction difficulties/issues to tank AY-102. Information gathered provides valuable insight regarding construction difficulties, future tank operations decisions, and guidance of the current tank inspection program. Should new waste storage tanks be constructed in the future, these reviews also provide valuable lessons-learned.(authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
241-AY-102 Leak detection pit drain line visual inspection - 15678
In October 2012, Washington River Protection Solutions LLC (WRPS) determined that waste had leaked into the annulus of Tank 241-AY-102. WRPS conducted an extensive review of Tank AY-102 and increased both inspection and monitoring of the tank; however, the precise cause and location of the leak could not be determined. In parallel with the leak in the primary tank, the Tank AY-102 leak detection pit (LDP) was accumulating water through the drain system external to the secondary tank liner. Liquid collecting in the LDP is suspected to be from water intrusion and collects at a rate such that the LDP must be pumped routinely. Following a routine pumping event on June 20, 2013, elevated radiation dose rates were noted on the transfer hose and surface contamination readings were found on the transfer pump when it was removed from the Tank AY-102 LDP. These two field readings suggested that tank waste from a secondary liner breach could be leaking into the LDP. As a result, WRPS initiated a plan to ascertain the integrity of the secondary tank liner including a robotic inspection of the LDP. To perform the robotic visual inspection, a custom robotic crawler with a deployment device was designed, built, and operated by IHI Southwest for WRPS to inspect the 6 in (152 mm) leak detection pit drain line. To ensure success when deployed in the field, the inspection equipment was demonstrated at both the IHI facility in Denver, Colorado, and the Hanford Site using full scale piping mockups. On November 20, 2013 WRPS inspected the 6 in (152 mm) diameter drain line. The deployment device successfully attached to the drain line, and the crawler entered the drain line and traversed to within approximately 7 ft (2.1 m) of the central sump located under the center of the tank before losing traction. Crawler performance was satisfactory, and the quality of the camera image and lighting provided sufficient detail to document the current condition of the visible regions of the pipe. The inspection showed that the majority of the drain line was dry. Two wet areas were observed, a portion of the line nearest the LDP and a portion near the center of the tank. The portion nearest the LDP was under water prior to pumping on November 14, 2013. Although sediment and debris were seen during the inspection, it is believed to be construction debris and corrosion products. No material was found in the inspection that looked like tank waste or the material seen in the Tank AY-102 annulus (i.e., no greenish or yellowish deposits or dark fluids, dried salt deposits, or crystalline material). The contamination levels seen on the crawler were consistent with past values seen on LDP pumping equipment. Sampling and analysis of the recovered residues from the crawlers did not find material consistent with tank waste. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗