Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “RADIOACTIVE WASTE PROCESSING”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 505 records · Page 28
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Dual solidification process of BN-350 liquid radioactive waste using high technology polymers and newly designed encapsulation techniques - 15198

Application of high technology polymers no.910 and no.960 manufactured by NOCHAR, USA, for treatment of liquid radioactive waste (LRW) have demonstrated good results at test sites worldwide. At the BN-350 site (Aktau, Kazakhstan), the tests were conducted successfully with contaminated oil, alkaline and salt containing LRW. This paper represents the results of immobilization of NOCHAR polymers, saturated with LRW, into solid matrix to comply with Kazakhstan regulatory requirements for long term storage and/or disposal. (authors)

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

New Formulation of Cast Stone for {sup 99}Tc Immobilization in Sulfate Rich Secondary Waste Stream - 16098

A low-temperature, cementitious waste form called Cast Stone (or grout) has been selected for solidification of the Effluent Treatment Facility (ETF)-treated wastes at the Hanford Site. Because the waste stream to be solidified may be relatively high in sulfate, the current Cast Stone dry blend formulation with ordinary Portland cement (OPC), fly ash (FA), and blast furnace slag (BFS) (47% BFS, 45% FA, and 8% OPC) may not be adequate. Thus a new formulation, called secondary waste grout, was proposed and tested. The secondary waste grout uses hydrated lime [Ca(OH){sub 2}] to tie up the sulfate initially such that ettringite [Ca{sub 6}Al{sub 2}(SO{sub 4}){sub 3}(OH){sub 12}.26(H{sub 2}O)] forms rapidly instead of forming as the cementitious waste form cures. Three different liquid waste simulants (242-A evaporator, Environmental Restoration Disposal Facility [ERDF] leachates, and Hanford Tank Waste Treatment and Immobilization Plant [WTP] off-gas condensates) were prepared and solidified using this new dry blend formulation. Baseline grout dry mixes were 20 wt% hydrated lime (HL), 35 wt% OPC, and 45 wt% BFS, and two different water-to-dry mix (w/dm) ratios (0.5 and 0.6) of free water mass to mass of dry blend were tested. After curing for a minimum of 28 days, the grout solidified waste forms were characterized and used for Tc leachability testing using the EPA 1315 Method. X-ray diffraction analysis confirmed that ∼12-15% of ettringite was formed in early stage of 28-day curing for the grouts prepared with the high sulfate WTP simulant and HL addition. In addition, the new formulation of secondary waste grout prepared with HL (20%), OPC (35%), and BFS (45%) at either 0.5 or 0.6 water to dry mix ratio yields higher average Tc interval leachability index (LI) values (12.5 to 13.9) after 28 to 90 days of leaching using deionized water, which is higher than the desired {sup 99}Tc LI value of 12 for grout destined for burial in the Integrated Disposal Facility at the Hanford Site. (authors)

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

Leak Testing with Simulated Waste of Hanford Tank Farm Valves Utilized for Double Valve Isolation - 16108

The existing Hanford Tank Farms Waste Transfer System has several models of ball valves used for double valve isolation (DVI) that have been installed for 10 or more years. The safety function of the safety-significant valves is to limit leakage of waste past the valves in order to decrease the consequences of a fine spray release due to a transfer misroute. While previous leak testing of the valves has been conducted, the testing did not address concerns in the Documented Safety Analysis concerns about the impact on valve operation and service life of the potential abrasive/erosive properties of the tank waste on the valves when cycled. Pacific Northwest National Laboratory (PNNL) conducted DVI tests at their Multi-Phase Transport Evaluation Loop Facility. Testing evaluated the leak rate of safety-significant isolation valves for DVI as a function of simulated operating cycles. PNNL developed a performance-based simulant specifically for this test program. The test environment simulated the abrasive characteristics of the Hanford Tank Farms Waste Transfer System during single-shell tank retrieval and waste feed delivery to the Hanford Tank Waste Treatment and Immobilization Plant. The testing consisted of periodically measuring leak rates and maximum operational torques on the DVI valves after prescribed numbers of valve operational cycles (open and close). The test results from the simulant cycle tests provide Washington River Protection Solutions with performance characteristics that can be used to verify compliance with the Documented Safety Analysis limits for valve seat leakage. (authors)

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

Impact of Corrections to the Spallings Volume Calculation on Waste Isolation Pilot Plant Performance Assessment - 16135

The numerical code DRSPALL (from direct release spallings) is written to calculate the volume of Waste Isolation Pilot Plant solid waste subject to material failure and transport to the surface (i.e., spallings) as a result of a hypothetical future inadvertent drilling intrusion into the repository. An error in the implementation of the DRSPALL finite difference equations was discovered and documented in a software problem report in accordance with the quality assurance procedure for software requirements. This paper describes the corrections to DRSPALL and documents the impact of the new spallings data from the modified DRSPALL on previous performance assessment calculations. Updated performance assessments result in more simulations with spallings, which generally translates to an increase in spallings releases to the accessible environment. Total normalized radionuclide releases using the modified DRSPALL data were determined by forming the summation of releases across each potential release pathway, namely borehole cuttings and cavings releases, spallings releases, direct brine releases, and transport releases. Because spallings releases are not a major contributor to the total releases, the updated performance assessment calculations of overall mean complementary cumulative distribution functions for total releases are virtually unchanged. Therefore, the corrections to the spallings volume calculation did not impact Waste Isolation Pilot Plant performance assessment calculation results. (authors)

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

Development of High Alumina Glass Property Data for Hanford High-Level Waste Glass Models - 16231

Roughly half of the projected Hanford high-level waste batches will have waste loadings limited by relatively high concentration of Al{sub 2}O{sub 3}. Individual glasses have been formulated and tested to demonstrate that it is possible to increase the loading of these high-Al{sub 2}O{sub 3} wastes in glass by as much as 50%. To implement such increases in waste loading in the Hanford Tank Waste Treatment and Immobilization Plant, the impact of composition on the properties of high-Al{sub 2}O{sub 3} waste glasses must be quantified in the form of validated glass property-composition models. To collect the data necessary for glass property-composition models, a multi-phase experimental approach was developed. In the first phase of the study, a set of 46 glass compositions were statistically designed to most efficiently backfill existing data in the composition region for high-Al{sub 2}O{sub 3} (15 to 30 wt%) waste glasses. The glasses were fabricated and key glass properties were tested: - Product Consistency Test (PCT) on quench (Q) and canister centerline cooled (CCC) samples - Toxicity Characteristic Leaching Procedure (TCLP) on Q and CCC samples - Crystallinity as a function of temperature (T) at equilibrium and of CCC samples - Viscosity and electrical conductivity as a function of T The measured properties of these glasses were compared to predictions from previously existing models developed over lower Al{sub 2}O{sub 3} concentration ranges. Areas requiring additional testing and modeling were highlighted. (authors)

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

200 West Pump and Treat: The First Three Years - 16473

The 200 West Pump and Treat (P and T), on the U.S. Department of Energy's Hanford Site, has a 9,464 liters per minute capacity designed to capture and treat an 8 km{sup 2} contaminated groundwater plume and reduce the mass of contaminants of concern (COCs) by 95 percent in 25 years. Treatable contaminants include carbon tetrachloride, trichloroethene, chromium, hexavalent chromium, nitrate, iodine-129 (I-129), and technetium-99 (Tc-99). After 3.5 years of continuous operation, the 200 West P and T treated over 10 billion liters of contaminated groundwater and removed over 190,000 kg of nitrate, 9,000 kg of carbon tetrachloride, nearly 5 curies of technetium-99, and smaller quantities of the remaining contaminants. Twenty three extraction wells strategically installed across the plumes pull contamination in from surrounding areas directing contaminated groundwater to the 200 West P and T for treatment. The 200 West P and T successfully removes all contaminants to below cleanup levels which are at (or lower than) the drinking water standard. Twenty one injection wells return treated water to the aquifer providing flow-path control to mitigate migration of contamination toward the Columbia River, a source of drinking water to the communities downstream. Contaminant concentrations in most monitoring wells are declining and the remedy is on target for accomplishing the mass removal goal ahead of schedule. In 2015, the 200 West P and T was expanded to include treatment for uranium from other operable units. With the uranium treatment expansion, the 200 West P and T is capable of cost-effectively treating contaminated groundwater beneath the 194 km{sup 2} Central Plateau. (authors)

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

Low Activity Waste Glass Waste Form Data Package for Hanford's Integrated Disposal Facility Performance Assessment - 16480

A Direct Feed Low Activity Waste (DFLAW) flowsheet has been initiated to begin immobilization of Hanford tank wastes. In the DFLAW configuration, a pretreatment system will segregate the high level and the low activity wastes (LAW). The LAW will be immobilized in the Waste Treatment Plant (WTP) and disposed of in Hanford's Integrated Disposal Facility (IDF). To obtain authorization to dispose of wastes in the IDF, a Performance Assessment (PA) must be completed in accordance with DOE Order 435.1. The PA shall include calculations of potential doses to representative future members of the public and potential releases from the facility to provide a reasonable expectation that performance objectives will not be exceeded as a result of operation and closure of the facility. To support the development of the PA, data from ILAW glass testing are needed to model the long term release of contaminants over the compliance period and verify that impacts to groundwater quality will be within performance objective limits. Washington River Protection Solutions is conducting an ILAW glass testing program to produce the required data. This program is a combined effort involving National Laboratories with known expertise in glass waste form research. The work involves accelerated testing to develop parameters that can be used in computer simulations of glass corrosion and contaminant release in the IDF environment. The results of this work will be compiled in an ILAW glass waste form performance data package for the IDF PA. (authors)

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

Testing of New Technetium Selective Media TcTreat - 16497

A new zirconium oxide based material TcTreat is under development and testing for the removal of radioactive oxo-anionic species (Tc-99 pertechnetate, Ru-106 ruthenate) from solution. TcTreat exhibited a very high {sup 99}Tc uptake over a broad pH-range of 4-10 and the uptake was reasonably high also in mildly alkaline and acidic ranges. Nitrate and sulphate had a decreasing effect on {sup 99}Tc uptake but is was still strong (k{sub d} = 100,000 ml/g and above) even at 1 molar concentrations.

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

Reevaluation of Actinide(IV)-Humic Complexation in the WIPP Performance Assessment - 16547

The legacy humic colloid model for tetravalent actinides (Th(IV), U(IV), Np(IV), and Pu(IV)) in the performance assessment (PA) of the Waste Isolation Pilot Plant (WIPP) is highly conservative. The model structure is feasible, but substantial reductions are needed for two constants, PHUMSIM and PHUMCIM. These constants are proportionality constants representing the equilibrium aqueous concentration ratio of humic-bound An(IV) to non-colloidal An(IV) for the Salado and Castile formations. In the WIPP PA model, both constants are set at 6.3 based on observed colloidal partitioning of Th(IV) in seawater. This value greatly enhances the mobile An(IV) concentration in the WIPP PA. Actual humic partitioning of An(IV) in WIPP brines is expected to be significantly lower than in seawater because the pH of WIPP brines (∼9) is higher, concentrations of competing cations (e.g., Mg{sup 2+}) are higher, and concentrations of aqueous humic substances may be lower. In this work, the results of recent studies of Th(IV)-humic and Ca{sup 2+}-humic complexation are used to simulate competitive humic complexation under WIPP conditions. The PHUMSIM and PHUMCIM values calculated for these simulations are in the range of 0.0013-0.0016 and 0.0047-0.0056, respectively. These values reduce humic-bound An(IV) to less than 1% of aqueous non-colloidal concentrations and would reduce mobile An(IV) concentrations in the WIPP PA by as much as 85%. (authors)

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

Low Activity Waste Pretreatment System (LAWPS) Conceptual Design Approach - 16568

The Low Activity Waste Pretreatment System (LAWPS) will be capable of providing the Waste Treatment and Immobilization Project's (WTP) Low Activity Waste Facility (LAW) the feed material needed to operate both of the LAW melters at full capacity. LAWPS will receive supernatant from the Hanford AP tank farm, filter solids from the waste, remove cesium from the waste, and then stage the feed in storage tanks for supplying the LAW facility. The LAWPS project team is currently executing the preliminary design phase of the project leading to Critical Decision 2 (CD-2). CD-2 is the approval of the performance baseline. The Critical Decision 1 (CD-1) package was approved by the Department of Energy Deputy Under Secretary in May 2015. This paper will focus on creating and gaining approval of the CD-1 package and initiating execution of the preliminary design work. The intent of the paper will be to highlight the activities that facilitated achievement of the goals and present key activities that have been performed to increase the likelihood of preliminary design success. Initiating the immobilization of Hanford tank waste will be a tremendous accomplishment. LAWPS is one of the key projects required to achieve this accomplishment. (authors)

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

One System Overview - 16579

The U.S. Department of Energy (DOE), Office of River Protection (ORP) is responsible for managing and completing the River Protection Project mission, which is to 'safeguard the nuclear waste stored in Hanford's 177 underground tanks, and to manage the waste safely and responsibly until it can be treated in the Waste Treatment and Immobilization Plant for final disposition'. The Office of River Protection's work scope is currently performed through two primary contracts: - The Tank Operations Contract, held by Washington River Protection Solutions LLC, (WRPS) includes the construction, operation, and maintenance activities necessary to safely store, retrieve, and transfer tank wastes; provide supplemental tank waste treatment; provide storage and/or disposal of primary and secondary waste streams; design, construction and commissioning of the Low-Activity Waste Pretreatment System; and support ORP to integrate Hanford Tank Waste Treatment and Immobilization Plant (WTP) completion and startup with Tank Farms operations. - The WTP Contract, held by Bechtel National, Inc. (BNI), includes the design, construction, and commissioning of a Pretreatment Facility, two vitrification facilities (one for high-level waste and one for low-activity waste), a dedicated analytical laboratory, and supporting facilities to treat radioactive tank wastes by immobilizing them into a stable glass waste form. One System was established as a means to improve the integration between the tank farms and the WTP project to support its safe and successful startup. One System's scope and purpose focus on mission integration consistent with DOE's plans to treat tank waste in phases, starting with direct feed of the low-activity waste stream to the WTP's Low-Activity Waste (LAW) Vitrification Facility (referred to as DFLAW). The One System organization now has four major focus areas: - Flowsheet Integration? Integrated River Protection Project (RPP) flowsheet development and management; developing a gaps, risks, and opportunities management plan and technical roadmap; and waste feed qualification. - Mission Analysis and Planning? Strategic planning, system planning, and modeling integration. - WTP Startup, Commissioning, and Operations Integration? Interface Control Document (ICD) management, coordinating facilities startup-to-commissioning-to-operations, contract directives and standards identification, and DFLAW program integration. - Project Integration and Controls? Integrated schedule, metrics/dashboards monitoring, and One System risk register. ORP established the DFLAW Program Office in February 2015 as one of its key performance goals. ORP staff, along with contractor managers, have identified roles and responsibilities for the each of the four major focus areas. One System has established an Executive Council and Governance Board to drive program progress and make decisions on DFLAW. This approach allows appropriate government and contractor senior management involvement in the DFLAW Program. Monthly critical path analysis on the integrated DFLAW schedule is being performed. Interface control documents specific to DFLAW have been developed, and system planning and modeling tools are being used to help define the DFLAW flowsheet. (authors)

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

Direct Feed Low Activity Waste Integrated Permitting - 16642

An overall Hanford permitting strategy for the U. S. Department of Energy (DOE) Office of River Protection (ORP) is being developed to support the Direct Feed Low- Activity Waste (DFLAW) Program. The strategy identifies new permits and modifications of existing permits, as well as major regulatory approvals to support the startup and operation of nuclear systems necessary to feed low activity tank waste, pretreat the waste, operate the Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) facility to treat tank waste, and dispose of waste streams. Types of permits include hazardous waste, toxic air, and radiological air licenses. Four different Contractors manage operations at Tank Farms, WTP, Utilities/Infrastructure, and Waste Disposal. Due to this complexity and the number of interfaces required, the need to have a strategic overview of all permits was evident. Approximately 25 permits and 4 major regulatory approvals are identified to implement DFLAW. The strategy will help guide integrated planning, scheduling and sequencing of permits and regulatory approvals to support DOE ORP's overall schedule for construction, commissioning and operation of DFLAW. Development of the strategy included extensive collaboration and coordination of an Integrated Permitting Team with staff and management representation from DOE, CH2M Hill Plateau Remediation Contractor (CHPRC), Washington River Protection Solutions LLC (WRPS), and Bechtel National Inc. (BNI). Information sessions and briefings have been conducted with the Washington State Department of Ecology (Ecology) and Washington State Department of Health (DOH) in the development of this overall strategy. Additionally, interface meetings are held with Ecology and DOH on specific projects early in the design phase to validate the permitting approach, identify key issues and information, and discuss requirements and assumptions. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

The Use of Macrophytes as Biosorbents in Radioactive Liquid Waste Treatment - 18039

An important stage of the management of radioactive liquid waste is the chemical treatment. In the last few years, bio-sorption has attracted attention as one alternative method to remove radionuclides in liquid LL/ILW due to its efficiency and low costs. There are many biomasses that can be applied for this purpose, as agricultural residues and Macrophytes. This study aims at studying Macrophytes (Pistia Stratiotes, Limnobium Laevigatum, Lemna sp and Azolla sp) ability to absorb uranium in liquid solutions. The bio-sorption capacity of uranium by the Macrophytes was experimentally determined. The experiments determine the metal uptake after the solution was in contact with each bio-sorbents by inductively coupled plasma optical emission spectrometry (ICP-OES). The results show that these materials are potentially applicable in the treatment of liquid radioactive waste. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Management of Tritium in HANARO (High Flux Advanced Neutron Application Reactor) - 18113

Tritium is generated inevitably from HANARO (High flux Advanced Neutron Application Reactor), a multi-purpose research reactor at the Korea Atomic Energy Research Institute (KAERI), because HANARO uses heavy water as a reflector. The specific activity of tritium in heavy water increases as the operation time increases. The release of tritium into the environment also increases as the specific activity of tritium in heavy water increases. Although the activity of tritium released from HANARO was less than 1/1,000 of the derived release limit regulated by the regulatory authority, for the last decade, significant effort has been exercised to reduce the activity of tritium released into the environment as well as the activity of tritium inside of HANARO to protect its workers. Recently the replacement of heavy water containing tritium by fresh heavy water was reviewed to maintain the activity of tritium in heavy water as low as possible. A replacement plan is being established based on the technical estimates and reviews and will be applied soon. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Backfilling of Geological Disposal Facilities - Development of Optimized Backfill Material - 18146

In Belgium, low- and intermediate-level waste (B-waste) will be conditioned in concrete monoliths and high-level waste (C-waste) in so-called Super-containers (SCs). The Belgian radioactive waste management program has focused on the disposal of these waste types in two emplacement fields of a geological disposal facility (GDF). When the disposal waste packages (DWP) have been emplaced, backfilling of the galleries is supposed to be carried out in order to stabilize the galleries, to reduce voids, to guarantee a favourable chemical milieu with regard to the retention of the radionuclides, to minimize a possible gas pressure build-up, to dissipate radioactive decay heat and to enable good conditions for a potential retrieval of the DWP. The current reference solution is to mix the backfill at the surface and then to pump the mixture through pipeline distribution systems into the underground structures. The catalogue of backfill material requirements comprises common, but also different requirements due to the characteristics of the B and C waste packages and differences in the backfilling systems. It was found that two backfill material recipes have to be developed. Different requirements, such as high porosity (low strength and low gas threshold pressure) and high thermal conductivity have contrary consequences for the material. In addition, during backfill production quality variations of the raw materials that influence the backfill material properties can occur. Different lengths of the delivery pipeline may require adjustments of the material composition. In order to consider the practical experiences of backfill material production, one focus of the development programs was to identify compositional ranges that guarantee the respective material property. A combination of the individual 'conformity fields' results in optimal solutions for the standard operating conditions as well as a compositional range that guarantees compliance with the required material specifications. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Adsorptive Removal of Cs-137 and Sr-90 from Water in the Spent Fuel Pool of Taiwan Research Reactor - 18169

The cleanup of spent fuel pool in Taiwan Research Reactor (TRR) is a significant milestone in the decommissioning project of TRR. Due to the water was polluted by the ruptured spent nuclear fuel rods, the fission products and actinides were required to be removed from the water prior to transporting the water to the radioactive liquid wastes treatment plant. A granular aluminosilicate adsorbent (namely GWC) was loaded into a special designed water submersion adsorber to remove radionuclides from water in consideration of the subsequent retrieving after used. The unit is able to be placed underwater without heavy shield shroud, and easily to be assembled and disassembled. More than 95% of β-emitters had been removed from the 980 m{sup 3} of contaminated water in the SFP and generated about 1.5 m{sup 3} of spent GWC which adsorbed with 4*10{sup 12} Bq of radionuclides. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Decommissioning Concept of Nuclear Fuel Cycle Facility - 18255

As the Korean Nuclear Safety Act was revised, it is urgent to prepare a decommissioning plan for the nuclear fuel cycle facilities operated by the Korea Atomic Energy Research Institute, KAERI. First, the basic concepts necessary for dismantling each facility and the order of dismantling for each dismantling work were determined. In this paper, we consider the disassembly order of the nuclear fuel cycle facilities such as the post irradiation fuel examination facility, the research reactor fuel production facility, the radioactive waste treatment facility, the radioactive waste form examination facility. The decommissioning plan for the research nuclear fuel cycle facilities will be based on the abovementioned dismantling basic concept and disassembly sequences. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗