Engineering topics

Poirier, M. R.

Publications and source records attributed to Poirier, M. R..

7 records

DOE OSTI2019

Solid-liquid Separation Testing for the Remediation of Hanford Waste Treatment Plant Low Activity Waste Melter Off-Gas Condensate

The Low Activity Waste (LAW) vitrification facility at the Hanford Waste Treatment and Immobilization Plant (WTP) will generate an aqueous condensate stream (LAW Off-Gas Condensate) from the off-gas system. The plan for disposition of this stream during Direct Feed LAW operations is to transfer it to the Effluent Management Facility (EMF), where it will be concentrated by evaporation and recycled to the LAW vitrification facility again. The primary reason to recycle this stream is so that the semi-volatile 99Tc isotope eventually becomes incorporated into the glass. However, this stream also contains non-radioactive salt components that are problematic in the melter, so diversion of this stream to another process would eliminate recycling of these salts and would enable simplified operation of the LAW melter and the Pretreatment Facilities. This diversion from recycling this stream within WTP would have the effect of decreasing the quantity of glass waste produced by allowing further increases in waste loading, resulting in a shortened LAW vitrification mission duration. The concept being tested here involves selectively removing the 99 Tc so that the decontaminated aqueous stream, with the problematic salts, can be disposed as a different waste form and avoid reprocessing through vitrification.

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DOE OSTI2019

Submersible Blend Pump Mixing Evaluation

Savannah River Remediation (SRR) requested Savannah River National Laboratory (SRNL) to perform an engineering analysis to investigate the mixing behavior in feed blend tanks for the Salt Waste Processing Facility (SWPF). The baseline for mixing the feed blend tanks is a U 0 D of 5.1 ft 2 /s, a pump nozzle elevation of 165.86 inches above the sludge layer and 174 inches above the tank bottom, a liquid level 174.28 inches above the pump nozzle, and a blend time of 10.63 hours. The current Salt Batch Plan identifies Tanks 21, 26, 41, and 42 as the designated blend tanks. This supplemental study only addresses Type IIIA tanks (i.e., Tanks 26, 41, and 42). Using the Tank 41 current configuration as the baseline, the analysis considers the impact on blending if: 1) the distance between the pump discharge nozzle and the liquid surface increases above the baseline, 2) the distance between the pump discharge nozzle and the liquid surface decreases below the baseline, 3) the distance between the pump discharge nozzle and the sludge layer at the bottom of the tank increases above the baseline, or 4) the distance between the pump discharge nozzle and the sludge layer at the bottom of the tank decreases below the baseline, each while maintaining the minimum U 0 D of 5.1 ft 2 /s. Per subsequent direction from SRR, the minimum distance between the pump discharge nozzle and the sludge will be 165.86 inches. Hence, distances less than 165.86 inches between the pump discharge nozzle and the sludge were not included in the analysis. In addition, SRR requested SRNL to evaluate the impact of the abandoned in place, failed slurry pumps in Tank 42 on liquid blending.

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DOE OSTI2019

Historical Scaling Performance from Laboratory to Full Scale for The Defense Waste Processing Facility's Chemical Process Cell

The Defense Waste Processing Facility (DWPF) is planning to modify the chemical processing flowsheet by replacing formic acid with glycolic acid in the Chemical Process Cell (CPC) Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME). The replacement of formic acid with glycolic acid virtually eliminates the CPC’s largest flammability hazards, catalytic hydrogen and ammonia.

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DOE OSTI2018

Hanford Direct Feed Low Activity Waste Real Time Monitoring Program - 18336

Effective operation of the Low-Activity Waste (LAW) Facility at Hanford will rely on information provided from monitoring and control of chemical process streams to maintain safety and environmental compliance, product quality, and operational efficiency. The LAW Facility has been designed as a contact-maintained facility and it was recognized that establishing a real time, in-line monitoring program could have substantial benefits to the U.S. Department of Energy, Office of River Protection in the long-term, which include significant time savings, increased processing efficiency and effectiveness, reducing worker exposure to radiation and chemical hazards, reducing secondary wastes, and a better understanding of the flowsheet to support direct-feed LAW (DFLAW). The Assistant Manager/Federal Project Director for the Waste Treatment and Immobilization Plant (WTP) Project chartered a multidisciplinary integrated technical team comprised of federal, contractor, and national laboratory staff to develop a phased program to support this initiative. A three-phase approach was adopted: - Phase 1: Requirements and Opportunities Analysis for Sampling Reduction; - Phase 2: Applications and Benefits Determination; - Phase 3: Qualification and Demonstration. The focus of Phase 1 is to identify the drivers behind any requirements for sampling and any opportunities to benefit from a real-time monitoring program. The effort identified 18 sample points and approximately 2,600 potential samples to be collected annually with analytical methods to be performed approximately 18,000 times annually. Based on Savannah River National Laboratory experience and discussions with WTP Analytical Laboratory personnel, these sample analyses will generate approximately 5,000 L of liquid secondary waste and approximately 1,300 m{sup 3} of solid secondary waste each year. Additional solid and liquid secondary wastes will be generated from sample collection. A preliminary evaluation indicates that employing real-time, in-line monitoring, mass balances, and periodic sampling could significantly reduce the number of samples collected, analytical methods performed, and secondary waste generated. (authors)

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DOE OSTI2018

Instrumentation for Hanford Direct-Feed Low-Activity Waste Real-Time, In-Line Process Monitoring - 18339

The direct-feed low-activity waste (DFLAW) process will utilize facilities in the Hanford tank farms to stage tank waste feed, a new facility to pretreat the tank waste feed, and facilities in the Hanford Waste Treatment and Immobilization Plant (WTP) to immobilize the low-activity waste (LAW) and disposition effluents from the vitrification process. Process sampling is used extensively throughout the DFLAW process to qualify waste feeds, control the process, and demonstrate compliance with regulatory and contractual commitments. The U.S. Department of Energy's Office of River Protection (ORP) has started a program to evaluate the potential benefits of replacing some sample collection requirements with realtime, in-line monitoring (RTIM). The program will identify, develop, and evaluate technologies that can reduce the number of samples required for WTP operation. Potential benefits of RTIM include elimination of process holds for sample analysis, a reduction in worker exposure to radiation and chemical hazards, decreased secondary waste volume, reducing the cost for sample collection and analysis, an improvement in product quality, and timely indication of process anomalies. In order to incorporate RTIM, the process control strategy for the overall process, as well as each unit operation, was reviewed and revisions to the strategies proposed. The following items were identified for incorporation of RTIM: - Real-time material balance calculations linked to the process control system; - Use of RTIM instruments to validate the material balance for selected analytes; - Anion analysis for determination of selected semi-volatile species (e.g., chlorine, sulfur, and fluorine) in the recycle stream. Based on the proposed process control strategy, a preliminary list of potential analytical equipment was developed. This was followed by a preliminary survey of instrument technologies currently on the market building on surveys performed for ORP, literature reviews, vendor web sites, and subject matter experts from the Savannah River National Laboratory and other U.S. Department of Energy national laboratories. Each technology was evaluated for measurement capability, operations and maintenance requirements, space requirements, and potential for application as process control instrumentation. The instrument technologies were chosen based on the following criteria: - Ability to perform analyses needed; - Potential to be used or adapted for use as process control instruments; - Potential to be adapted to size and operational constraints of standard WTP sample cabinets; - Operational and maintenance requirements. (authors)

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DOE OSTI2015

Properties important to mixing and simulant recommendations for WTP full-scale vessel testing

Full Scale Vessel Testing (FSVT) is being planned by Bechtel National, Inc., to demonstrate the ability of the standard high solids vessel design (SHSVD) to meet mixing requirements over the range of fluid properties planned for processing in the Pretreatment Facility (PTF) of the Hanford Waste Treatment and Immobilization Plant (WTP). Testing will use simulated waste rather than actual Hanford waste. Therefore, the use of suitable simulants is critical to achieving the goals of the test program. WTP personnel requested the Savannah River National Laboratory (SRNL) to assist with development of simulants for use in FSVT. Among the tasks assigned to SRNL was to develop a list of waste properties that are important to pulse-jet mixer (PJM) performance in WTP vessels with elevated concentrations of solids.

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DOE OSTI2015

MST Filterability Tests

The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). The low filter flux through the ARP has limited the rate at which radioactive liquid waste can be treated. Recent filter flux has averaged approximately 5 gallons per minute (gpm). Salt Batch 6 has had a lower processing rate and required frequent filter cleaning. Savannah River Remediation (SRR) has a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. In addition, at the time the testing started, SRR was assessing the impact of replacing the 0.1 micron filter with a 0.5 micron filter. This report describes testing of MST filterability to investigate the impact of filter pore size and MST particle size on filter flux and testing of filter enhancers to attempt to increase filter flux. The authors constructed a laboratory-scale crossflow filter apparatus with two crossflow filters operating in parallel. One filter was a 0.1 micron Mott sintered SS filter and the other was a 0.5 micron Mott sintered SS filter. The authors also constructed a dead-end filtration apparatus to conduct screening tests with potential filter aids and body feeds, referred to as filter enhancers. The original baseline for ARP was 5.6 M sodium salt solution with a free hydroxide concentration of approximately 1.7 M.3 ARP has been operating with a sodium concentration of approximately 6.4 M and a free hydroxide concentration of approximately 2.5 M. SRNL conducted tests varying the concentration of sodium and free hydroxide to determine whether those changes had a significant effect on filter flux. The feed slurries for the MST filterability tests were composed of simple salts (NaOH, NaNO 2 , and NaNO 3 ) and MST (0.2 – 4.8 g/L). The feed slurry for the filter enhancer tests contained simulated salt batch 6 supernate, MST, and filter enhancers.

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