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At least 613 records · Page 34
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Radioactive Waste Disposal Strategies within the US Army Corps of Engineers FUSRAP - 18328

The U.S. Army Corps of Engineers' (USACE) highest priority is the protection of human health and the environment and public and worker safety during the cleanup, transportation, and disposal of Formerly Utilized Sites Remedial Action Program (FUSRAP) material. In addition to following all appropriate federal and state rules and regulations, the USACE has its own safety program that ensures that we are being protective. One aspect of the USACE FUSRAP is the radioactive waste disposal strategies that we must consider. The USACE will only dispose of FUSRAP material in a facility that is licenses/permitted to accept it. The estimated exposures to facility workers and members of the public from the permitted disposal of FUSRAP wastes is evaluated as part of this process. The USACE uses the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) process to study and remediate FUSRAP sites. An evaluation is performed to decide whether it is best to manage the waste on-site or off-site and the requirements for disposal. The action selected must be protective of human health and the environment and must comply with regulations. When making the decision, there are several other factors taken into consideration including cost of the disposal and whether the public and state agencies support the action. Prior to determining disposal options, wastes must first be characterized. This involves an evaluation of both site history and analytical data. Determining the proper disposal requirements and subsequent disposal option involves: Characterizing the waste as stated above. This is important because there are several regulatory agencies which may oversee management of the waste. The US Nuclear Regulatory Commission, the US Environmental Protection Agency (US EPA), the US Department of Transportation, and state hazardous waste and/or radiation protection agencies may all have varying degrees of involvement. Identifying disposal requirements. Certain wastes must be disposed at licensed radioactive waste disposal facilities. Wastes containing US EPA regulated hazardous waste must be disposed at permitted hazardous waste disposal facilities. Certain wastes must be disposed at facilities licensed/permitted for both radioactive and hazardous waste. Some lower activity wastes may be accepted for disposal at other types of landfills. Considering acceptance criteria of the disposal facility. Radionuclides and/or hazardous constituents in the waste, as well as physical and chemical form of the waste, are evaluated to ensure they meet the acceptance criteria of the receiving facility's license and/or permit. If they don't, another disposal location must be used. Considering the accessibility and location of the disposal facility. Some facilities are able to accept shipments only by truck and others can accept material via railcar as well. The distance to a disposal facility impacts the risk of transportation accidents and efficient use of project resources such as the number of trucks required to perform the transportation. These factors are also important in evaluating whether material can be cost effectively shipped to a disposal facility. Evaluating the compliance status of the receiving facility. It is not assumed that just because a facility has a license or permit that it is acceptable for the USACE' waste. Prior to selecting a facility for disposal of FUSRAP waste, a site visit, audit and consultation with the US EPA is required to determine whether there are any known relevant violations at the facility. Facilities that have violations that negatively impact the USACE or US EPA approval of the facility are not used for disposal of FUSRAP waste. Once a facility is selected. The USACE procures contracts, or utilizes existing contracts, to facilitate the transportation and disposal action. Additionally, the USACE continues to consult with US EPA routinely to confirm the compliance status of the facility. Considering state acceptance of wastes to a facility. The USACE seeks to obtain written authorization from the facility state regulator indicating the action is compliant with existing licenses, permits, laws, and regulations. Each of these factors is considered by the USACE in selecting a FUSRAP disposal location. The goal is to provide safe, cost effective disposal which is protective of human health and the environment and which complies with all regulatory requirements. These steps all feed in to the disposal strategy consideration that USACE must go through for our FUSRAP waste streams. There are a number of challenges in the process to include In order to achieve the Congressional mandate of completing cleanup work under FUSRAP in a more cost effective, timely manner, while assuring protection of public health and safety. USACE must determine all disposal options that are available for the types of waste at each FUSRAP site. As a solution, completion of a disposal strategy document can help ensure this goal is met and will foster consistency across the FUSRAP. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2013

Waste Management Improvement Initiatives at Atomic Energy of Canada Limited - 13091

Atomic Energy of Canada Limited's (AECL) Chalk River Laboratories (CRL) has been in operation for over 60 years. Radioactive, mixed, hazardous and non-hazardous wastes have been and continue to be generated at CRL as a result of research and development, radioisotope production, reactor operation and facility decommissioning activities. AECL has implemented several improvement initiatives at CRL to simplify the interface between waste generators and waste receivers: - Introduction of trained Waste Officers representing their facilities or activities at CRL; - Establishment of a Waste Management Customer Support Service as a Single-Point of Contact to provide guidance to waste generators for all waste management processes; and - Implementation of a streamlined approach for waste identification with emphasis on early identification of waste types and potential disposition paths. As a result of implementing these improvement initiatives, improvements in waste management and waste transfer efficiencies have been realized at CRL. These included: 1) waste generators contacting the Customer Support Service for information or guidance instead of various waste receivers; 2) more clear and consistent guidance provided to waste generators for waste management through the Customer Support Service; 3) more consistent and correct waste information provided to waste receivers through Waste Officers, resulting in reduced time and resources required for waste management (i.e., overall cost); 4) improved waste minimization and segregation approaches, as identified by in-house Waste Officers; and 5) enhanced communication between waste generators and waste management groups. (authors)

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

Commercial Submersible Mixing Pump For SRS Tank Waste Removal - 15223

The Savannah River Site Tank Farms have 45 active underground waste tanks used to store and process nuclear waste materials. There are 4 different tank types, ranging in capacity from 2839 m 3 to 4921 m 3 (750,000 to 1,300,000 gallons). Eighteen of the tanks are older style and do not meet all current federal standards for secondary containment. The older style tanks are the initial focus of waste removal efforts for tank closure and are referred to as closure tanks. Of the original 51 underground waste tanks, six of the original 24 older style tanks have completed waste removal and are filled with grout. The insoluble waste fraction that resides within most waste tanks at SRS requires vigorous agitation to suspend the solids within the waste liquid in order to transfer this material for eventual processing into glass filled canisters at the Defense Waste Processing Facility (DWPF). SRS suspends the solid waste by use of recirculating mixing pumps. Older style tanks generally have limited riser openings which will not support larger mixing pumps, since the riser access is typically 58.4 cm (23 inches) in diameter. Agitation for these tanks has been provided by four long shafted standard slurry pumps (SLP) powered by an above tank 112KW (150 HP) electric motor. The pump shaft is lubricated and cooled in a pressurized water column that is sealed from the surrounding waste in the tank. Closure of four waste tanks has been accomplished utilizing long shafted pump technology combined with heel removal using multiple technologies. Newer style waste tanks at SRS have larger riser openings, allowing the processing of waste solids to be accomplished with four large diameter SLPs equipped with 224KW (300 HP) motors. These tanks are used to process the waste from closure tanks for DWPF. In addition to the SLPs, a 224KW (300 HP) submersible mixer pump (SMP) has also been developed and deployed within older style tanks. The SMPs are product cooled and product lubricated canned motor pumps designed to fit within available risers and have significant agitation capabilities to suspend waste solids. Waste removal and closure of two tanks has been accomplished with agitation provided by 3 SMPs installed within the tanks. In 2012, a team was assembled to investigate alternative solids removal technologies to support waste removal for closing tanks. The goal of the team was to find a more cost effective approach that could be used to replace the current mixing pump technology. This team was unable to identify an alternative technology outside of mixing pumps to support waste agitation and removal from SRS waste tanks. However, the team did identify a potentially lower cost mixing pump compared to the baseline SLPs and SMPs. Rather than using the traditional procurement using an engineering specification, the team proposed to seek commercially available submersible mixer pumps (CSMP) as alternatives to SLPs and SMPs. SLPs and SMPs have a high procurement cost and the actual cost of moving pumps between tanks has shown to be significantly higher than the original estimates that justified the reuse of SMPs and SLPs. The team recommended procurement of “off-the-shelf” industry pumps which may be available for significant savings, but at an increased risk of failure and reduced operating life in the waste tank. The goal of the CSMP program is to obtain mixing pumps that could mix from bulk waste removal through tank closure and then be abandoned in place as part of tank closure. This paper will present the development, progress and relative advantages of the CSMP.

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

Commercial submersible mixing pump for SRS tank waste removal - 15223

The Savannah River Site Tank Farms have 45 active underground waste tanks used to store and process nuclear waste materials. There are 4 different tank types, ranging in capacity from 2839 m{sup 3} to 4921m{sup 3} (750,000 to 1,300,000 gallons). Eighteen of the tanks are older style and do not meet all current federal standards for secondary containment. The older style tanks are the initial focus of waste removal efforts for tank closure and are referred to as closure tanks. Of the original 51 underground waste tanks, six of the original 24 older style tanks have completed waste removal and are filled with grout. The insoluble waste fraction that resides within most waste tanks at SRS requires vigorous agitation to suspend the solids within the waste liquid in order to transfer this material for eventual processing into glass filled canisters at the Defense Waste Processing Facility (DWPF). SRS suspends the solid waste by use of recirculating mixing pumps. Older style tanks generally have limited riser openings which will not support larger mixing pumps, since the riser access is typically 58.4 cm (23 inches) in diameter. Agitation for these tanks has been provided by four long shafted standard slurry pumps (SLP) powered by an above tank 112 kW (150 HP) electric motor. The pump shaft is lubricated and cooled in a pressurized water column that is sealed from the surrounding waste in the tank. Closure of four waste tanks has been accomplished utilizing long shafted pump technology combined with heel removal using multiple technologies. Newer style waste tanks at SRS have larger riser openings, allowing the processing of waste solids to be accomplished with four large diameter SLPs equipped with 224 kW (300 HP) motors. These tanks are used to process the waste from closure tanks for DWPF. In addition to the SLPs, a 224 kW (300 HP) submersible mixer pump (SMP) has also been developed and deployed within older style tanks. The SMPs are product cooled and product lubricated canned motor pumps designed to fit within available risers and have significant agitation capabilities to suspend waste solids. Waste removal and closure of two tanks has been accomplished with agitation provided by 3 SMPs installed within the tanks. In 2012, a team was assembled to investigate alternative solids removal technologies to support waste removal for closing tanks. The goal of the team was to find a more cost effective approach that could be used to replace the current mixing pump technology. This team was unable to identify an alternative technology outside of mixing pumps to support waste agitation and removal from SRS waste tanks. However, the team did identify a potentially lower cost mixing pump compared to the baseline SLPs and SMPs. Rather than using the traditional procurement using an engineering specification, the team proposed to seek commercially available submersible mixer pumps (CSMP) as alternatives to SLPs and SMPs. SLPs and SMPs have a high procurement cost and the actual cost of moving pumps between tanks has shown to be significantly higher than the original estimates that justified the reuse of SMPs and SLPs. The team recommended procurement of 'off-the-shelf' industry pumps which may be available for significant savings, but at an increased risk of failure and reduced operating life in the waste tank. The goal of the CSMP program is to obtain mixing pumps that could mix from bulk waste removal through tank closure and then be abandoned in place as part of tank closure. This paper will present the development, progress and relative advantages of the CSMP. (authors)

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

Household-level dynamics of food waste production and related beliefs, attitudes, and behaviours in Guelph, Ontario

Highlights: • We combined household waste stream weights with survey data. • We examine relationships between waste and food-related practices and beliefs. • Families and large households produced more total waste, but less waste per capita. • Food awareness and waste awareness were related to reduced food waste. • Convenience lifestyles were differentially associated with food waste. - Abstract: It has been estimated that Canadians waste $27 billion of food annually, and that half of that waste occurs at the household level (Gooch et al., 2010). There are social, environmental, and economic implications for this scale of food waste, and source separation of organic waste is an increasingly common municipal intervention. There is relatively little research that assesses the dynamics of household food waste (particularly in Canada). The purpose of this study is to combine observations of organic, recyclable, and garbage waste production rates to survey results of food waste-related beliefs, attitudes, and behaviours at the household level in the mid-sized municipality of Guelph, Ontario. Waste weights and surveys were obtained from 68 households in the summer of 2013. The results of this study indicate multiple relationships between food waste production and household shopping practices, food preparation behaviours, household waste management practices, and food-related attitudes, beliefs, and lifestyles. Notably, we observed that food awareness, waste awareness, family lifestyles, and convenience lifestyles were related to food waste production. We conclude that it is important to understand the diversity of factors that can influence food wasting behaviours at the household level in order to design waste management systems and policies to reduce food waste.

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

Cementation of Nuclear Wastes: From Past to Future in a Sustainable Approach - 18266

Cementation of nuclear wastes is a widespread technology due to several factors such as excellent feedback from past experience, simplicity of implementation and versatility. Indeed, as nuclear wastes come in many physical states (bulk wastes, powders, sludges), cementation is the immobilisation process that can easily accommodate this large range of wastes provided the appropriate mixing technology is used: heterogenous cementation (grouting of bulky wastes) or homogenous cementation (intermixing process between the powder or the sludge and the cementitious material). However, nuclear wastes equally present an important chemical variability. This is especially true as New Areva's range of nuclear activities covers the entire fuel cycle: mining, conversion, enrichment and recycling and dismantling and decommissioning. The chemical interactions between the waste and the cement matrix are carefully studied by New Areva's R and D teams in order to provide comprehensive solutions by developing cement formulations which are adapted to wastes characteristics. The aim of the studies is to obtain cement waste-forms that meet the waste acceptance criteria, the final product being thus in perfect adequacy with the disposal requirements. For over 30 years New Areva has been developing cement formulations adapted to the physical and chemical specificities of the wastes accounting for constrains imposed by waste characteristics. The overall approach includes the definition of the appropriate cement composition at laboratory scale, engineering design, equipment manufacturing, testing and commissioning of the cementation facilities. With this strong technical background, a specific methodology has been developed by New Areva teams in order to allow a rapid screening of possible solutions for a given waste (in terms of cement chemistry adapted to the waste) in a learn-fast approach that is based on theoretical analysis and small-scale tests. The methodology was applied for wastes presenting a complex nature (such as reactive metals, ion exchange resins, oils and solvents, mercury, etc), known to interact with Portland cement from a chemical point of view and leading to durability issues of the wasteform (swelling, strength reduction, leaching) and thus reducing the final waste loading. Once the screening process is over, the main drivers for choosing the most appropriate solution to be further developed at pilot scale are: reducing the overall volume and the impact of the final waste package, ensure the waste package performance as defined by the disposal requirements and control the long-term behaviour in final disposal. Moreover, a modelling approach is addressed, aiming to develop a thermo-chemo-mechanical (THM) concrete models that are able to predict the behaviour of the structure (waste form) in time. The aim of the present paper is to describe the main principles within the developed methodology and illustrate it by using a few specific examples. Several distinct cement formulations are developed for complex wastes, limiting the chemical interaction between the cement matrix and the given wastes, obtaining better waste loadings and better overall durability behaviour which facilitates long term behaviour demonstration. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Minimizing Transuranic Waste Generated in Hot Cells at Oak Ridge National Laboratory Through Use of a Non-Destructive CO{sub 2} Pellet Cleaning System - 19577

Wastes generated in shielded hot cells containing materials contaminated with transuranic (TRU) waste present unique problems in waste disposal at Department of Energy (DOE) sites. Oak Ridge National Laboratory (ORNL) routinely processes materials contaminated with TRU waste from the High Flux Isotope Reactor (HFIR) and from other sources (both on and off-site) in their hot cell facilities, generating wastes that require eventual disposal. The waste streams generated by these processes are often high activity and exhibit high dose rates, driving them into the remote-handled (RH) category at the Waste Isolation Pilot Plant (WIPP). Reduction of the TRU waste footprint is desirable from a disposal cost perspective due to constraints with RH waste processing and a lack of space availability at the WIPP. Historically TRU waste generated at ORNL has been processed by the TRU Waste Processing Center (TWPC), which belongs to the Department of Energy's Office of Environmental Management (DOE-EM). Now that Oak Ridge legacy TRU waste is reaching its final stage, DOE-EM has turned over the mission of processing newly-generated TRU waste streams to the DOE Office of Science at ORNL. To reduce the volume of potential TRU waste occupying valuable space in the ORNL Hot Cells, a non-destructive CO{sub 2} pellet cleaning system will be used to capture particulate contaminants removed from the surfaces of waste inside the ORNL Non-Reactor Nuclear Facilities (NNFD) Hot Cells at the Irradiated Fuels Examination Laboratories (IFEL). The particulate will be segregated by particle size and captured for disposal later. This action will separate some of the TRU isotopes (particulate) from the larger waste volume (debris waste items), resulting in both lower waste disposal costs and reduced TRU waste volumes. This will be accomplished through a specialized cyclone separator. Secondary wastes are usually generated through other methods of decontamination, such as water jets and abrasive agents. These secondary wastes are absent with the CO{sub 2} pelletized system, due to sublimation of the dry ice upon impact. This is an important consideration with IFEL, a facility whose primary mission is to perform a series of R and D testing on nuclear fuel rods. Liquid is not a feasible method of decontamination as the IFEL's drains in the Hot Cells were plugged years ago due to Resource Conservation and Recovery Act (RCRA) regulations. Constraints at IFEL, such as criticality safety concerns with use of hydrogenous materials, are also alleviated with the non-destructive CO{sub 2} pellet cleaning system. These are a couple of the considerations why this method of decontamination is preferred. Due to concerns with oxidizers at WIPP grouting will be performed on the contaminated particulate produced during the trapping by the cyclone separation phase. This method will comply with mitigating oxidizing properties in TRU waste, required by the recently published Basis of Knowledge (BoK) document as part of Acceptable Knowledge (AK) by WIPP. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Improving PCM Waste Management Through New Approaches to Screening for LLW Treatment and Disposal - 20145

A major step forward in the management of Plutonium Contaminated Material (PCM) Waste has been taken at the Sellafield site with the introduction of new capabilities to enable wastes previously conservatively designated as PCM Intermediate Level Waste (ILW) to be re-classified for treatment as Low Level Waste (LLW). The Sellafield site, located in the North West of England, within the United Kingdom (UK), has operated plutonium processing plants and waste facilities for almost 70 years. During this time management of the raw PCM waste produced has presented a variety of challenges. The waste is currently processed by high force waste compaction in the Waste Treatment Complex (WTC). The WTC converts 200 litre drums of raw PCM waste into a compacted, grout encapsulated monolith form within stainless steel containment, ready for emplacement within the UK's Geological Disposal Facility (GDF) when it becomes available. To help progress some of the wastes waiting for treatment, recent improvements have been made with the introduction of new waste assay instrumentation which enables the identification of a 'candidate' waste potentially suitable for disposal via the LLW treatment route. Opening a new LLW route for previously designated PCM has been a major advance in PCM waste management policy. It has required a range of technical assessment arrangements to be developed, tested and commissioned and involved the engagement of a wide range of stakeholders. In particular, very detailed technical analysis methods have been developed to ensure that there is a robust and conservative approach to the final sentencing of waste. Following completion of commissioning tests, the first 86 m{sup 3} of previously designated PCM waste was successfully treated through the LLW route and consigned to LLW disposal in June 2019. The direct benefit of sentencing waste to the correct waste route (LLW) is the significant cost savings across the complete range of waste management activities. This work is also strategically important for demonstrating to a range of stakeholders including workforce and regulators, that waste previously designated as PCM can be re-classified in a systematic and justifiable way without increasing risk to personnel or the wider environment. By ensuring that waste is being managed appropriately it will be possible to carry out more remediation work safely, in less time, and at a lower cost. (authors)

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

Radioactive Waste Management in a Treatability and Optimisation Perspective - 17527

In order to meet recycling criteria or to fulfil Waste Acceptance Criteria (WAC) for disposal there are many different management concepts for radioactive waste that can be applied. Which concept or set of concepts to use to optimize waste management depends on several factors, among them, the regulatory framework for recycling, the availability of a disposal facility and the acceptance criteria for disposal. The required pre-treatment and other pre-disposal activities should be carefully analyzed for each of the disposal options, as they are significant contributors to the total cost for managing the waste. Waste Acceptance Criteria are living documents that should be updated when regulatory framework changes as well as when new treatment methods and new packaging and barrier systems develop. Each waste treatment facility, has its own specific limitations and therefore its own WAC/CFA (conditions for acceptance), which depends both on the plant design and national legislation. Many waste owners, countries or licensees, have their preferred, and in some cases well established, waste routes for certain waste streams. In some countries, the full chain from waste treatment through to disposal of radioactive waste is in place, whilst other countries still are in the process of establishing their repository program. The worst case scenario for any licensee or waste owner is waste which is not possible to qualify for disposal. This can be due to poor or degraded waste containers, unspecified content in waste packages, or wastes that are not suitable for disposal in their current form. Such deficiencies result in expensive actions related to waste retrieval, new characterisation and/or costly investigations. The EDF Group has a fleet of waste treatment facilities and has, for decades, provided waste treatment services to domestic and international customers. This paper will discuss important waste owner considerations and EDF experiences related to the optimization of the waste management process. This will be from both a treatment and an end-state perspective. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2013

Supplemental Immobilization of Hanford Low-Activity Waste: Cast Stone Screening Tests

More than 56 million gallons of radioactive and hazardous waste are stored in 177 underground storage tanks at the U.S. Department of Energy’s (DOE’s) Hanford Site in southeastern Washington State. The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the wastes and immobilize them in a glass waste form. The WTP includes a pretreatment facility to separate the wastes into a small volume of high-level waste (HLW) containing most of the radioactivity and a larger volume of low-activity waste (LAW) containing most of the nonradioactive chemicals. The HLW will be converted to glass in the HLW vitrification facility for ultimate disposal at an offsite federal repository. At least a portion (~35%) of the LAW will be converted to glass in the LAW vitrification facility and will be disposed of onsite at the Integrated Disposal Facility (IDF). The pretreatment and HLW vitrification facilities will have the capacity to treat and immobilize the wastes destined for each facility. However, a second LAW immobilization facility will be needed for the expected volume of LAW requiring immobilization. A cementitious waste form known as Cast Stone is being considered to provide the required additional LAW immobilization capacity. The Cast Stone waste form must be acceptable for disposal in the IDF. The Cast Stone waste form and immobilization process must be tested to demonstrate that the final Cast Stone waste form can comply with the waste acceptance criteria for the disposal facility and that the immobilization processes can be controlled to consistently provide an acceptable waste form product. Further, the waste form must be tested to provide the technical basis for understanding the long-term performance of the waste form in the disposal environment. These waste form performance data are needed to support risk assessment and performance assessment (PA) analyses of the long-term environmental impact of the waste disposal in the IDF. The PA is needed to satisfy both Washington State IDF Permit and DOE Order requirements. Cast Stone has been selected for solidification of radioactive wastes including WTP aqueous secondary wastes treated at the Effluent Treatment Facility (ETF) at Hanford. A similar waste form called Saltstone is used at the Savannah River Site (SRS) to solidify its LAW tank wastes.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Nuclear Criticality Safety Assessment of Criticality Control Containers without Moderation Control at the Waste Isolation Pilot Plant

The Waste Isolation Pilot Plant (WIPP) provides for safe, permanent disposal of government-owned transuranic (TRU) and TRU mixed wastes. Receipt and disposal of waste at the WIPP site began in March 1999. The Sandia report, Consideration of Nuclear Criticality When Disposing of Transuranic Waste at the Waste Isolation Pilot Plant, addressed potential nuclear criticality safety issues based on the projected inventory characteristics known at the time [1]. As designs for inventory, waste forms, and disposal packages have changed, new analyses have been performed, and updates have been made to address any potential effects to the WIPP safety basis. New analyses performed include Saylor 2017 [2] and Brickner 2019 [3], which address certain waste containers with specified loadings under post-closure conditions. Both examined several hypothetical scenarios and included analyses to bound (from a criticality potential standpoint) credible configurations that could occur at WIPP during the repository regulatory post-closure disposal time period for feature, event, and process (FEP) considerations—10,000 years. During this post-closure period at WIPP, the screening of FEPs is governed by the risk-based standards and implementing regulations of the US Environmental Protection Agency (EPA) (i.e., 40 CFR 191 and 40 CFR 194, respectively) [4,5]. An FEP screening can be based on either a low-consequence or low-probability rationale. A low-probability rationale includes either (a) a qualitative rationale that the FEP is not credible or (b) a quantitative demonstration that the probability is less than 10-4 in 104 years. In this evaluation, a qualitative lowprobability rationale of not credible is used by demonstrating that bounding configurations of the waste are not critical. The demonstration of subcriticality is through quantitative calculations, but a probability of criticality is not evaluated. Rather, the rationale for this evaluation is that bounding configurations with an effective neutron multiplication factor (keff) well below the upper subcriticality limit (USL) make criticality incredible. Reference [2] documented a nuclear criticality assessment of the WIPP repository for disposal of dilute surplus plutonium materials using the Dilute and Dispose Approach and packaging in criticality control overpacks (CCOs). The CCO is the waste disposal container recently designed to allow for up to 380 fissile gram equivalent (FGE) 239 Pu per drum, which is a higher fissile loading than typical waste containers. The CCO consists of a criticality control container (CCC) positioned by upper and lower plywood spacers within a standard 55 gal drum. The CCC is used to establish a geometry control for fissile materials during transportation and WIPP emplacement operations. The current WIPP waste acceptance criteria for CCO payloads limit beryllium to less than or equal to 1% by weight of the waste contents and require the waste form to be non-machine compacted. Reference [2] considered two scenario progressions—room closure from salt creep, hereafter referred to as the reconfigured dry scenario, and flooding with brine, hereafter referred to as the reconfigured wet scenario. The subsequent drying out of the reconfigured wet scenarios was also considered. For all scenarios, subcriticality was maintained when 50 g of B 4 C (acting as a neutron absorber) per CCC was intermixed within the plutonium disposition waste form. The analysis used a waste form description that limits the amount of moderation that could be present within the waste form (i.e., it limits the amount of water and polyethylene that could be present based on planned processing conditions). This analysis to evaluate increased limits on the amount of moderation that could be present was performed as a companion to Reference [2] to address concerns associated with verifying moisture and/or plastic contents of waste materials following packaging of dilute surplus plutonium in the CCO. To that end, this analysis used the models and methods from Reference [2] to evaluate a more generic base waste form consisting of water and polyethylene that is more similar (and nearly identical) to the generic waste forms utilized in other models/analyses supporting the TRU Package Transporter Model II (TRUPACTII) safety analysis [6] (all are without moderation controls). The waste form in this analysis uses a base mixture of 75% water and 25% polyethylene, the total amount of which is varied to determine the optimum moderation to fissile material (H/Pu) ratio. The fissile loading is maintained at up to 380 FGE 239 Pu (modeled as PuO 2 ) per CCO with an additional 545 g of beryllium (to bound the 1% by weight contents restriction) and 50 g of B 4 C intermixed per CCO. The beryllium content (1% by weight) is based on the total allowed waste weight (this does not include packaging and container weights). Figures ES-1 and ES-2 display summary results, showing that with this model including 50 g of B 4 C per CCO, the system keff remains under 0.85 for all moderator amounts and provides a significant margin against post-closure criticality under postulated bounding conditions for compaction. Figure ES-1 compares an infinite model with a room model at the initial emplacement spacing and under full radial compaction. Full radial compaction places each CCC in direct contact and does not credit any anticipated spacing associated with current post-closure geomechanical modeling of the repository [7]. The effects of variations in the H/Pu ratio were evaluated by varying the amount of the water/polyethylene component of the waste model, with fissile loading maintained at 380 239 Pu FGE. Similarly, Figure ES-2 illustrates how various amounts of B 4 C per CCO influence k eff at different radial compactions, all at the H/Pu ratio of 200 (in the room array model). Therefore, while the results from Saylor 2017 [2] modeled more realistic process limits associated with packaging of dilute surplus plutonium, this analysis demonstrates that limits on moderation (plastic and water content) are not necessary to ensure subcriticality in the WIPP repository, provided the requisite B 4 C absorber is present.

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

Gas retention and release from Hanford Site sludge waste tanks - 15491

Radioactive wastes from nuclear fuel processing are stored in large underground storage tanks at the Hanford Site. Solid wastes can be divided into salt-cake (mostly precipitated soluble sodium nitrate and nitrite salts with some interstitial liquid consisting of concentrated salt solutions) and sludge (mostly low solubility aluminum and iron compounds with relatively dilute interstitial liquid). Waste generates hydrogen through the radiolysis of water and organic compounds, radio-thermolytic decomposition of organic compounds, and corrosion of a tank's carbon steel walls. Nonflammable gases, such as nitrous oxide and nitrogen, are also produced. Additional flammable gases (e.g., ammonia and methane) are generated by chemical reactions between various degradation products of organic chemicals present in the tanks. Six double-shell tanks (DSTs) containing salt-cake wastes began showing signs of gas accumulation and buoyant instability in the form of periodic waste level drops in the 1980's. Studies in the 1990's indicated that gas would accumulate in the settled solids layer until its bulk density was lower than the supernatant liquid. The resultant gas release caused by this instability was termed a Buoyant Displacement Gas Release Event (BDGRE). Criteria were developed to prevent forming additional waste tanks that exhibited BDGREs. Significant gas accumulation and BDGREs were never observed in tanks containing predominantly sludge wastes. Literature reviews, data from Hanford Site waste tanks, and experiments with waste simulants have led to new conclusions on gas retention and release in sludge waste. The data show similar overall behavior where initially the settled solids volume increases as gas bubbles form. Gas fraction in the settled solids increases to a peak concentration after which additional generated gas escapes through connected cracks and there is a balance between gas generation and gas release with little change in gas fraction. Experiments showed that this behavior does not change as sludge waste depth increases. Sufficient data now exist to differentiate between gas retention and release behavior in Hanford Site sludge waste tanks and salt-cake waste tanks. The salt-cake criteria do not need to be applied to sludge waste tanks that exhibit certain gas retention and release behavior. Criteria for waste characteristics and process behavior have been defined that identify specific wastes and tanks that, based on previous operating experience, will have low gas retention and will not exhibit large, spontaneous releases. The first criterion defines what waste is considered sludge and what waste is considered salt-cake. If the mass ratio of soluble to insoluble constituents is below 2.5, then the waste is sludge. The second criterion is a density difference criterion that prevents tanks being operated in a region where sludge buoyancy might occur. For large gas releases to occur, the settled solids must accumulate sufficient gas to become less dense than the overlying supernatant (i.e., the settled solids would become buoyant). Based on previous operating experience, the ratio of liquid density to degassed settled solids bulk density (ρl/ρB) should be maintained at ≤ 0.84. This ensures that retained gas content in the sludge would need to exceed 16% by volume for the settled solids to become buoyant in the overlying supernatant. Tank waste that satisfies the mass ratio criterion, the liquid to bulk solids density criterion, and has process data supporting typical Hanford waste sludge behavior does not pose a significant risk for a large spontaneous gas release event. (authors)

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DOE OSTI2018

U.S. Nuclear Regulatory Commission Historical Perspectives of Very Low-Level Radioactive Waste - 18367

The United States Nuclear Regulatory Commission (NRC), in Title 10 of the Code of Federal Regulations Part 61 (10 CFR Part 61), 'Licensing Requirements for Land Disposal of Radioactive Waste', provides licensing procedures, performance objectives, and technical requirements for the issuance of licenses for the land disposal of low-level radioactive waste. Low-level radioactive waste is divided into four categories based on its potential risk and need for isolation. Class A is the lowest category of low-level radioactive waste and poses the least risk. A large percentage of Class A low-level waste contains very low radionuclide concentrations and does not pose a significant health and safety risk. In the current regulatory framework, this waste, referred to as low-activity or very low-level waste, is managed in the same manner as much more hazardous waste. In 1986 and 1990, as a result of the Low-Level Radioactive Waste Policy Amendments Act of 1985, the NRC issued the Below Regulatory Concern (BRC) policy statement. This policy statement established an implementation plan regarding the expeditious handling of rulemaking petitions 'to exempt specific radioactive waste streams from regulation due to the presence of radionuclides in sufficiently low concentrations or quantities as to be below regulatory concern.' The BRC policy statement provided a consistent risk framework when considering regulatory exemption decisions, such as: (1) the release for unrestricted public use of lands and structures containing residual radioactivity; (2) the distribution of consumer products containing small amounts of radioactive material; (3) the disposal of very low-level radioactive waste at other than licensed disposal sites; and (4) the recycling of slightly contaminated equipment and materials. Due to concerns with the BRC policy that were raised by Congress, the States, the public, and others, Congress enacted the Energy Policy Act of 1992, which revoked the NRC's 1986 and 1990 BRC policy statements and led to the NRC's formal withdrawal of the BRC policy in 1993. Stakeholders raised concerns on NRC's potential deregulation of radioactive material. Additionally, in March 2005, the NRC staff proposed a rule to amend 10 CFR Part 20, 'Standards for Protection Against Radiation,' to include radiological criteria for controlling the disposition of solid materials with very small amounts of residual radioactivity. The NRC staff also proposed a limited disposition approach for the disposition of solid material, limiting the release of solid material meeting a 0.01 milli-Sievert per year (mSv/yr) [1 milli-rem (mrem/yr)] dose criterion, from licensed control. In June 2005, the Commission disapproved publication of the proposed rule and deferred the rulemaking until a later time, stating that the NRC's existing approach of reviewing specific cases on an individual basis was fully protective of public health and safety. This rulemaking effort was discontinued by the Commission in 2016. Recently, several nuclear power plant licensees have announced early decommissioning of their facilities. Some stakeholders have expressed concerns about the capacity and disposal costs associated with using the four existing low-level waste disposal sites for very low levels of radioactive waste (i.e., waste at the low end of the Class A category). A more risk-informed, performance based approach to waste disposal would allow more flexibility in managing this waste commensurate with its risk and hazard. A new approach would also allow the NRC to align with international standards for this type of waste. The NRC is presently conducting a scoping study to identify the actions the agency should take to strengthen its regulatory framework for very low-level waste disposal. The Very Low-Level Waste (VLLW) scoping study will consider divergent stakeholder comments; lessons learned from the BRC policy statements and the proposed rule on radiological criteria for controlling the disposition of solid materials; and best practices of other countries with respect to VLLW disposal. The NRC will also engage other government agencies to discuss regulatory options for VLLW. This paper offers a historical overview of past NRC initiatives to manage the lower end of Class A waste in a manner that is risk informed and performance based. It examines previous endeavors and discusses the regulatory challenges that arose. It also addresses lessons learned and introduces NRC's current effort regarding very low-level radioactive waste disposal. (authors)

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DOE OSTI2015

Destined for indecision? A critical analysis of waste management practices in England from 1996 to 2013

Highlights: • Critical analysis of municipal waste management practices and performance in England. • Trends visualised via innovative ternary plots and changes and reasons explored. • Performance 1996–2013 moved slowly away from landfill dominance. • Large variations in %s of waste landfilled, incinerated and recycled/composted. • Progress to resource efficiency slow; affected by poor planning and hostile disputes. - Abstract: European nations are compelled to reduce reliance on landfill as a destination for household waste, and should, in principle, achieve this goal with due recognition of the aims and principles of the waste hierarchy. Past research has predominantly focused on recycling, whilst interactions between changing waste destinies, causes and drivers of household waste management change, and potential consequences for the goal of the waste hierarchy are less well understood. This study analysed Local Authority Collected Waste (LACW) for England, at national, regional and sub-regional level, in terms of the destination of household waste to landfill, incineration and recycling. Information about waste partnerships, waste management infrastructure and collection systems was collected to help identify and explain changes in waste destinies. Since 1996, the proportion of waste landfilled in England has decreased, in tandem with increases in recycling and incineration. At the regional and sub-regional (Local Authority; LA) level, there have been large variations in the relative proportions of waste landfilled, incinerated and recycled or composted. Annual increases in the proportion of household waste incinerated were typically larger than increases in the proportion recycled. The observed changes took place in the context of legal and financial drivers, and the circumstances of individual LAs (e.g. landfill capacity) also explained the changes seen. Where observed, shifts from landfill towards incineration constitute an approach whereby waste management moves up the waste hierarchy as opposed to an attempt to reach the most preferred option(s); in terms of resource efficiency, this practice is sub-optimal. The requirement to supply incinerators with a feedstock over their lifespan reduces the benefits of developing of recycling and waste reduction, although access to incineration infrastructure permits short-term and marked decreases in the proportion of LACW landfilled. We conclude that there is a need for clearer national strategy and co-ordination to inform and guide policy, practice, planning and investment in infrastructure such that waste management can be better aligned with the principles of the circular economy and resource efficiency. If the ongoing stand-off between national political figures and the waste sector continues, England’s waste policy remains destined for indecision.

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DOE OSTI2018

WIPP Space Faces TRU Waste Disposal Limits; The Volume Reducing Solution - 18365

Transuranic (TRU) waste packaging for removal from a glovebox has for many years involved the use of bags as the primary containment. In many cases, many hydrogenous layers of bags, yards of tape, and multiple filters are added to the waste stream in order to get the TRU waste into the final 55 gallon drum package to be shipped and buried at the Waste Isolation Pilot Plant (WIPP). The WIPP is currently limited to a total finite disposed volume of Contact Handled (CH) and Remote Handled (RH) TRU waste. As of early 2014 over half of the allotted WIPP volume had been filled with mainly CH-TRU waste. Based on current bag operation packaging methods used, the Department of Energy's (DOE) remaining CH and RH waste will not fit in the remaining limited WIPP space. Bag operations, can be performed safely by good operators following tedious repetitive processes and many Administrative Safety Controls. Since the bag is the only confinement layer between the contamination and the operator, contamination incidents can occur. Bag-out operations require close proximity to the waste to perform the process. With some waste streams, this close to waste proximity increases operator radiation dose. Central Research Laboratories (CRL), based in Red Wing Minnesota, who for many decades has developed proven engineered material transfer solutions based around their Rapid Transfer Port (RTP) technology, has worked with DOE sites to develop a TRU Waste Management Solution. The solution is a single filtered large Polyethylene (PE) or Stainless Steel (SST) Rapid Transfer Port container in a standard Department of Transportation (DOT) 7A, Type A drum, which allows for loading of TRU waste directly from the operational glovebox without the use of bags, sleeves or tapes to provide leak tight containment. All operator interventions to connect and disconnect a drum to and from the glovebox are achieved in an upright ergonomic position by one (1) operator in less than three (3) minutes. Minimal As Low As Reasonably Achievable (ALARA) levels are achieved during connect and disconnect of the drum, due to the engineered safety controls of the RTP. The CRL RTP solution allows glovebox or re-packaged TRU waste to be safely transferred to the final 55 Gallon drum container without additional bags or tape. The high diffusion coefficient filter on the CRL RTP 55G container and elimination of added hydrogenous packaging, improves the Decay Heat Limit (DHL) per drum for most TRU waste types compared with bagged drums, and in most cases allows more TRU waste to be loaded per drum. Inorganic TRU waste materials can be packaged directly into the CRL RTP SST drum container to the maximum DHL and Fissile Gram Equivalent (FGE) allowable for a drum. This paper will show how highly efficient TRAMPAC approved TRU waste packaging of CH and RH TRU waste can be accomplished in a safer, cost effective manner without adding any additional packaging materials to the waste stream, thus increasing the chance of placing all DOE's legacy and to be generated TRU waste in the remaining WIPP space. (authors)

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DOE OSTI2019

EPA's Suite of Tools for Managing Waste Following a Large-Scale Incident - 19420

Large-scale disasters have the potential to generate a significant amount of waste. For example, Hurricane Katrina and the Joplin Missouri tornado resulted in 100 million and 1.5 million cubic yards of waste respectfully. Man-made chemical, biological, radiological or nuclear (CBRN) incidents either by way of terrorism, war, or accidents have the potential to generate as much or more hazardous waste. Recovery is profoundly impacted by waste management issues. The quantification, segregation, transportation, and storage of waste can be an arduous and costly undertaking. Furthermore, these processes are intricately linked with decisions made throughout the recovery timeline. Therefore, the remediation, including waste management, must be holistically considered. Understanding these complex interactions can be facilitated by using models and tools that adhere to the 'system-of-systems' approach. To better understand and predict waste management issues the Environmental Protection Agency's (EPA's) Homeland Security Research Program (HSRP) is developing a suite of tools and resources for planning and recovery purposes. The waste management suite consists of four tools: - Incident Waste Decision Support Tool (I-WASTE): characterizes and produces order-of-magnitude estimates for the weight and volume of waste materials that may require management and/or disposal, as well as identifies and locates potential treatment and disposal facilities. - Waste Estimation Support Tool (WEST): estimates waste generated from remediation and cleanup activities following a wide-area radiological or biological incident; - Waste Storage and Staging Tool: identifies and prioritizes potential locations for staging and storing waste; - Waste Logistics Tool: estimates optimal routes with consideration to cost, time, and logistical requirements (e.g., resource demand, transportation type, access limitations, etc.) associated with transporting large volumes of waste from disaster-stricken areas to intermediate waste staging/temporary storage/on-site processing sites to off-site waste management facilities; and This paper will present EPA's waste management suite of tools, their purpose and application to large-scale incidents, and a case study demonstrating their use in a hypothetical scenario. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Declaration of the Chemical Composition of Waste-products for the German Repository Konrad Using Substance Vectors - 20500

The waste acceptance criteria of the German repository Konrad require beside a radiological declaration a compositional declaration to be able to avoid negative impact on the groundwater by a presumed leakage into the groundwater after complete corrosion of the containers in the future. The declaration of the composition has to specify compounds and substances not element analyses, because the chemical behavior and toxicity especially of organic compounds varies strongly The relevant compounds have to be described and quantified using defined substance codes provided by the operator. For simple waste types like pure concrete or steel components, the definition of the composition is rather simple. The composition of more complex waste streams is generally declared using producer specific material vectors, which can be derived for defined waste types (e.g. grouted fluids, ash from combustion, super-compacted mixed waste etc.). Additional substance vectors exist for containers, drums and grout, which together with the waste composition yield the total composition of the waste packages. The substance vectors for homogeneous waste streams like cementitious demolition waste, solidified fluids and ash are mostly based on analyses provided by the waste owner. In some cases, analyses from non-radioactive analogues or data sheets can also be used to demonstrate the composition. For each qualified treatment of radioactive waste streams the material composition is described and balanced on the basis of specific material vectors, which are composed of material codes from the material and cask list provided by the Federal company for radioactive waste disposal. For mixed waste streams like super-compacted or grouted mixed waste or materials simply packed in containers an analyses cannot be used. In these cases, the compositional information from the bookkeeping can be used for the entire waste stream to calculate a mean composition including a compositional range (min / max composition). Only waste packages with an approved material description can be delivered to Konrad. Therefore, the material declaration of all waste streams and the resulting waste products is crucial for all waste owners in Germany to be able to have enough waste packages ready, when the repository is going to open in 2027. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Idaho-Developed Technologies, Processes Offer Unique Solutions to Waste Management Challenges - 19281

INL Site cleanup contractor Fluor Idaho, LLC (Fluor Idaho) and its predecessors have developed a host of state-of-the-art technologies and specialized processes for nuclear waste handling, treatment, storage, and shipping. The cleanup program has also repurposed and upgraded previously idled Cold War-era buildings to treat and repackage both on- and off-site generated radioactive and hazardous wastes. And lastly, Fluor Idaho is using one-of-a-kind equipment to protect waste management personnel as they undertake their work to meet cleanup commitments that the Department of Energy (DOE) made to the state of Idaho. Such applications, although developed for Idaho's wastes, have the potential to benefit other facilities within the DOE Complex. Engineers and fabricators have teamed up to develop truly unique devices made of specialized metals, like stainless steel alloys, and more readily available materials such as Lexan. All waste types that Fluor Idaho manages daily - spent nuclear fuel, both high- and low-level wastes, and both remote-handled (RH) and CH-TRU - benefit from these innovations. Without question, the greatest number of specialized equipment, processes, and worker-protection technologies developed are for the retrieving, characterizing, repackaging, and shipping of TRU wastes, which makes sense considering the INL Site stores the most TRU waste in the DOE Complex. On the CH-TRU retrieval front, crews are using specially modified Gradall excavators to protect workers while they exhume Rocky Flats Plant wastes that were sent to Idaho in the 1950's and 1960's and buried in a shallow landfill. The excavators are supplied with extra Lexan windows to protect operators from the potential for flying debris during exhumation. On-board supplied air, pumped into the cab, and individual air supplies protect workers from inhalation hazards. Also on-board infrared cameras allow operators to detect heat generating from reactive metals at the dig face. At the Advanced Mixed Waste Treatment Facility (AMWTP), Brokk robotic arm operators use a 'super clam' claw, designed and built at the INL Site, on the remotely operated heavy equipment to size-reduce waste boxes, drums, concrete, and metal containing TRU constituents. The super clam is so powerful and dexterous that operators can crush a 55-gallon drum into the size of a basketball, but also delicately turn the pages of a magazine. Boxes too large to be sized at the AMWTP's box-lines are sent to the Accelerated Retrieval Project VII facility to be sized by Waste Management personnel. Such waste boxes, which sometimes contain 'flighty' plutonium-238 material, have forced the project to employ a heavily ventilated and filtered interior tent. Not all technologies developed for the Waste Management program are high-technology; in fact, one piece of equipment is so simple it's literally ingenious. Operators who inspect and repackage RH-TRU inside a hot cell at the Idaho Nuclear Technology and Engineering Center (INTEC) needed a backup plan in case the hot cell port couldn't be closed in the event of a power outage. Engineers and fabricators collaborated to develop a port cover actuator mechanism, which allows operators to open and close the cell's hatch cover with nothing more than a cordless drill. Also at INTEC, Maintenance Shop fabricators developed a Lexan container or 'pig' suitable for shielding neutron-emitting TRU waste sources. Lexan was chosen as the preferred shielded container material for this special type of waste because neutrons are best shielded with materials containing lots of hydrogen, such as plastics, which are composed of carbon and hydrogen molecules. Once approved for shipment, the high-activity waste will be loaded into specialty casks and shipped to WIPP for permanent disposal. Although all these technologies and processes were initially developed for resolving challenges at the INL Site, their applications could be far-reaching. Like the INL Site, many other facilities in the DOE Complex manage, treat, store, and ship TRU, low-and high-level wastes, and spent nuclear fuel. The technologies and processes developed in Idaho protect Waste Management personnel as they undertake their work, but these benefits could be utilized by other facilities and personnel doing similar work. (authors)

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