Workshop: Best-practice for laboratory testing low-permeable materials

The testing of low-permeable materials is challenging. Yet, for the disposal of radioactive waste, it is essential, too. This workshop is aimed at gathering ambitious scientists to discuss and to collaborate on their experiences in the laboratory testing of low-permeable materials. The focus here is on the methods: What method is best for what kind of low-permeable host rock (salt/clay) and for what kind of technical barrier material (bentonite/crushed salt)? How can measurement errors be correctly determined? What are the crucial “bottlenecks” in the device setups? How can high porous but low permeable samples best be pre-saturated? How can coupled flow and cumbersome gas traps in the tests be dealt with? What is the best-practice analysis of permeability from pressure decay recordings? Is there a hope of defining a standardized procedure for low-permeability testing? These points will be reflected in the light of radioactive waste disposal and in the need to find a best-practice solution when it comes to eventual evaluation and comparison of potential underground disposal sites.

Method for Radioactive Waste Disposal in Underground Mines

This paper presents the key parameters associated with the disposal method used to dispose of radioactive waste (RW) of Class 2 and 3 in abandoned underground mines of PIMCU site assuming additional isolation of RW containers, adjustment of bedrock geomechanical properties and compliance with regulatory requirements. The paper briefly analyzes international practices focused on RW disposal in natural and artificial underground cavities. It provides a comparison between the forecasted volumes of RW generation at the enterprises of the State Corporation Rosatom and the available underground disposal capacity at PIMCU site. It presents the main characteristics of a paste filling manufactured based on materials from uranium ore processing and used as an insulating filler inside the vaults. The paper summarizes the results of operations on rock mass reinforcement based on an injection method. It indicates the key advantages of the proposed method.

Microbial Processes in Engineering Clay Materials and Biocidal Additives to Prevent Them

Microbial activity in engineering clay materials of safety barriers in conditions, simulating a deep underground disposal point of radioactive waste Yeniseiskii (Zheleznogorsk, Krasnoyarsk Kray) has been studied. It was established that clays with a high content of sulfur, iron and organic carbon, as well as those containing mineral phases (calcites, spars, and others) can be a source of microbial gas release, including methane, and also of products (for instance, hydrogen sulfide), which may be corrosive to steals in contact with clay materials. The microbial processes in clays rich in biogenic elements and minerals lead to the dissolution of aluminosilicate structural lattices. To prevent the microbial impact, various biocidal additives are used: Amanat, Rancid, boric acid and polyhexamethylguanidine (PHMG). The effect of these preparations at various temperatures was analyzed. It was found that PHMG was the most effective among the tested preparations over a wide temperature range. radioactive waste, microbial activity biological destruction, biocides

2019 Performance Assessment Calculations for the Recertification of the Waste Isolation Pilot Plant

<p>The Waste Isolation Pilot Plant (WIPP), located in southeastern New Mexico, has been developed by the U.S. Department of Energy (DOE) for the geologic (deep underground) disposal of transuranic (TRU) waste. Containment of TRU waste at the WIPP is regulated by the U.S. Environmental Protection Agency (EPA) according to the regulations set forth in Title 40 of the Code of Federal Regulations (CFR), Part 191. The DOE demonstrates compliance with the containment requirements according to the Certification Criteria in Title 40 CFR Part 194 by means of performance assessment (PA) calculations performed by Sandia National Laboratories (SNL). WIPP PA calculations estimate the probability and consequence of potential radionuclide releases from the repository to the accessible environment for a regulatory period of 10,000 years after facility closure.</p><p>The models used in PA are maintained and updated with new information as part of an ongoing process. Improved information regarding important WIPP features, events, and processes typically results in refinements and modifications to PA models and the parameters used in them. Planned changes to the repository and/or the components therein also result in updates to WIPP PA models. WIPP PA models are used to support the repository recertification process that occurs at five-year intervals following the receipt of the first waste shipment at the site in 1999.</p><p>The 2019 Compliance Recertification Application (CRA-2019) is the fourth WIPP recertification application submitted for approval by the EPA. A PA has been executed by SNL in support of the DOE submittal of the CRA-2019. Results found in the CRA-2019 PA are compared to those obtained in the 2014 Compliance Recertification Application (CRA-2014) PA in order to assess repository performance in terms of the current regulatory baseline. This presentation includes a summary of the changes modeled in the CRA-2019 PA, as well as the estimated releases over the assumed 10,000-year regulatory period. Changes incorporated into the CRA-2019 PA included repository planned changes, parameter updates, and refinements to PA implementation.</p><p>Overall, the total normalized releases for the CRA-2019 PA have increased at all probabilities compared to those from the CRA-2014 PA. Releases from each of the four potential release mechanisms tracked in WIPP PA (cuttings and cavings, spallings, releases from the Culebra formation, and direct brine releases) have also increased at all probability levels. Cuttings and cavings releases continue to dominate total releases at high probabilities and direct brine releases continue to dominate total releases at low probabilities. Although the calculated releases have increased, the total normalized releases continue to remain below regulatory limits. As a result, the CRA-2019 PA demonstrates that the WIPP remains in compliance with the containment requirements of 40 CFR Part 191.</p><p>Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.. This research is funded by WIPP programs administered by the Office of Environmental Management (EM) of the U.S. Department of Energy. SAND2020-0131A</p>

Hydrogeological condition of wastewater disposal in the territory of the Novoportovsky oil and gas condensate field

Significant amounts of liquid industrial and domestic waste are generated at oil fields in the north territory of Western Siberia. There are currently no reliable methods of purification and utilization for many of them. It is very difficult to ensure long-term isolation of the waste from the hydrosphere and biosphere on the Earth. Underground disposal of wastewater in deep horizons (depths of the Earth) is one way to prevent from their negative impact on the environment and public health.

Neutrosophic Optimization Model and Computational Algorithm for Optimal Shale Gas Water Management under Uncertainty

Shale gas energy is the most prominent and dominating source of power across the globe. The processes for the extraction of shale gas from shale rocks are very complex. In this study, a multiobjective optimization framework is presented for an overall water management system that includes the allocation of freshwater for hydraulic fracturing and optimal management of the resulting wastewater with different techniques. The generated wastewater from the shale fracking process contains highly toxic chemicals. The optimal control of a massive amount of contaminated water is quite a challenging task. Therefore, an on-site treatment plant, underground disposal facility, and treatment plant with expansion capacity were designed to overcome environmental issues. A multiobjective trade-off between socio-economic and environmental concerns was established under a set of conflicting constraints. A solution method—the neutrosophic goal programming approach—is suggested, inspired by independent, neutral/indeterminacy thoughts of the decision-maker(s). A theoretical computational study is presented to show the validity and applicability of the proposed multiobjective shale gas water management optimization model and solution procedure. The obtained results and conclusions, along with the significant contributions, are discussed in the context of shale gas supply chain planning policies over different time horizons.