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At least 721 records · Page 40

Overview of the Life Sciences Glovebox (LSG) Facility

The Life Sciences Glovebox (LSG) is a rack-level payload facility designed to house biological investigations in a "workbench" type environment aboard the International Space Station (ISS). The facility is scheduled to be launched in September 2018 and will be installed in the Japanese Experiment Module (JEM) of the ISS. LSG is comprised of an extendable work volume, an airlock, an avionics package, a laptop, and supporting structure. The 450L work volume provides two levels of containment for investigations via the physical barrier of its structure and an internal, filtered airflow that results in a negative pressure relative to ISS cabin pressure. The facility provides many other resources for investigation use including 28 VDC power, 120 VAC power, heat rejection, data connections, and video. Portions of the interior surfaces of the work volume are ferrous, allowing investigations and supporting hardware to be magnetically affixed to these surfaces. A UV decontamination system and a variety of ancillary hardware are available for investigations to use while occupying LSG. An engineering unit on the ground is used for payload development and integrated verification testing. Once the facility is installed and commissioned, it will be managed by the same team that manages the Microgravity Science Glovebox (MSG), another rack-level payload facility that has been operating aboard the ISS since 2002. Experienced Investigation Payload Integration Managers (IPIMs), who also support MSG payloads, will be available to assist payload developers through the integration process. This presentation will provide an overview of the LSG facility and the planned investigation flow for the near future.

Jordan, Lee↗

Impact of Facility Pressure on the Wear of the NASA HERMeS Hall Thruster

This work presents an overview and summary of the results acquired during the final segment of the TDU-3 Long Duration Wear Test, which was completed in October 2018. The overall goal of this segment was to quantify the impact of facility pressure on the wear of the Hall Effect Rocket with Magnetic Shielding Technology Demonstration Unit Three (TDU-3) Hall thruster. This was accomplished by operating TDU-3 for approximately 270 hours at the nominal 600 V/12.5 kW operating condition while a bleed or auxiliary flow of xenon propellant was injected into the vacuum facility in order to raise the operating pressure to match that of another test facility in which previous wear segments had been performed. The performance, plume, stability, and wear results acquired at this elevated pressure (11.7 µTorr) are compared with equivalent data taken at the nominal operating pressure (4.2 µTorr) in the same facility as well at the elevated operating pressure in the other facility. Implications of these results for acquiring facility-independent service life estimates are discussed.

Frieman, Jason D.↗

A Preliminary Study of Inter-Facility LWC Differences in Appendix C and Supercooled Large Drop Conditions due to Calibration Instruments

The simulation of clouds containing Supercooled Large Droplets has received increasing attention due to the introduction of Appendix O and future associated requirements for means of compliance. Supercooled Large Droplet conditions can cover four orders of magnitude in drop sizes, imposing a larger instrument measurement challenge than for Appendix C conditions. Wind tunnel facilities have adopted different instrumentation for liquid water content measurement, with fundamentally different principles of operation. In order to explore the comparability of the different instruments used for Appendix C and SLD measurement, and its impact on confidence in measurements used for means of compliance, a project was established to conduct a series of dedicated tests at three wind tunnel facilities. To date, liquid water content measurements have been completed using a Multi-Element sensor as the common instrument at two of the facilities. The data have provided preliminary information suggesting that substantial inter-facility differences likely exist in liquid water content estimates in Supercooled Large Droplet conditions that appear to be largely attributable to the choice of calibration instruments. These results are dependent on the assumption that the Multi-Element probe would produce equivalent measurements at the two facilities if the liquid water content were the same, regardless of other environmental differences that may exist between the two facilities. Planned further testing with other liquid water content measurement techniques may provide further information to confirm or refute the results of this study.

aircraft icing↗

New Hayabusa2 and OSIRIS REx Curation Facilities at Nasa Johnson Space Center

Asteroids are made up of rocky material that is left over from the formation of our solar system [1]. This material holds the key to unlocking information about the history of the planets and our sun. Hayabusa2 and OSIRIS-REx are two sample return missions that have collected rocky material from carbonaceous asteroids which are rich in water, carbon, and organic compounds [1]. Hayabusa2 is a spacecraft that collected samples from asteroid Ryugu launched by the Japan Aerospace Exploration Agency (JAXA). Samples were returned to Earth in December 2020 and 10 percent of the collected material is currently housed in a state-of-the-art laboratory at NASA Johnson Space Center (JSC) dedicated to Ryugu material [1]. OSIRIS-REx is a spacecraft launched by NASA that collected samples from asteroid Bennu. The samples are on their journey to Earth and will arrive in September 2023. They will be stored in a separate cleanroom dedicated to Bennu material. From these two missions, scientists will examine dust particles and rocky material to research clues on how the early solar system formed and how life began [2]. Because these samples are so precious and rare, it is important to keep them free from Earth contamination. In September of 2020, a massive construction project began to provide curation facilities to meet the needs of two incoming asteroid collections, Hayabusa2 and OSIRIS-REx. Despite numerous setbacks caused by the coronavirus pandemic, these facilities have been completed in the fall of 2021. Some of these setbacks included strict PPE requirements, keeping safe working distances as well as access to the facilities as NASA was operating under a Stage 3 condition in response to the pandemic. These facilities will provide curation laboratories to safely house the precious asteroid samples as well as facilities to manipulate samples, do sample preparation and process samples into and out of the labs for future studies by the scientific community. The lab suite consists of several different rooms including an initial anteroom (ISO 7), a staging area (ISO 7), two gowning areas (one for OSIRIS-REx and one for Hayabusa2; both ISO 6)), the Haybusa2 Curation Laboratory (ISO 5), the OSIRIS-REx Curation Laboratory (ISO 5), an ultramicrotomy laboratory (ISO 7) and a thin section laboratory (not a cleanroom). To maintain cleanliness levels necessary for these lab spaces quarterly to monthly Balazs organic and inorganic sampling has been conducted on a regular basis before, during and after the construction project to monitor the cleanliness levels in the new labs that will house the asteroid samples. These new facilities feature a Ruuvi (Grafana) monitoring system that measures temperature, humidity, and pressure of the lab suite. This is a small puck shaped sensor that sends signals to the Grafana cloud where the data can be plotted and set up on dashboards within the lab suite. These sensors are easy to set up and install and they run off a cell battery that is good for 3-5 years before needing replacement. This system can deliver text messages and emails to the appropriate personnel when values fall outside of set limits. In addition to the monitoring system, this new lab suite features viewing windows from several different locations and sliding motion censored doors. We have obtained some state-of-the-art equipment to outfit the lab spaces (desiccators, microscopes, ultramicrotome) and are in the process of outfitting the suite with additional items such as: nitrogen gloveboxes, additional desiccators, micromanipulators, etc. The Hayabusa2 samples provided to NASA by JAXA included 23 millimeter sized grains and 4 containers with finer material. OSIRIS-REx is expected to return as much as 400 grams of asteroid Bennu. Samples will be stored in a nitrogen glove box and separated into nitrogen sealed transfer containers. Small Bennu and Ryugu particles will be handled and prepared (e.g., ultra-thin sections for scanning electron microscopy (SEM) or transmission electron microscopy (TEM)) using an Axis Pro micromanipulator and Leica EM UC7 ultramicrotome. Analyzing samples at the atomic scale will provide greater insight to the origins of the solar system and life formation on Earth. All the curation preparation for these sample collections is essential to ongoing research and efforts to understand our solar system, both nowand for future generations.

Curation↗

Artemis Crewed Surface Operations Training Dust Mitigation Test/Training Facility (DMTF)

Based on several Apollo mission(s) reports and lessons learned1 on lunar dust impacts, it is imperative for successful Artemis missions, to develop dust mitigation methods & train crew in dust cleaning techniques for efficient use of lunar surface time and for crew health. Longer durations and increased number of Extra Vehicular Activities (EVAs) for Artemis need better training. Apollo missions lacked training in a dust facility. Current facilities do not provide adequate fidelity to train crew in dust cleaning operations in suited, pressurized environments. Mimicking dust cleaning actions in existing facilities (eg- Neutral Buoyancy lab) does not provide in depth understanding of actions and time needed to clean suit or positions crew need to take to remove dust from suit. Available dust bins do not support suited/pressurized ops, personnel not trained in suited ops, more overhead/travel. A local facility at Johnson Space Center (JSC) w/ adequate fidelity supporting suited/pressurized ops, personnel in suited ops is a crucial need for rapid development/testing and training. This facility will provide NASA capabilities to: 1. Provide a dust containment bin to perform suited pressurized crewed training/testing activities for dust interaction/mitigation leveraging existing JSC facility infrastructure and 2. Perform end-to-end simulated lunar dust testing of fluid, mechanical, and electrical systems to provide “test like you fly” confidence for industry developed solutions.

EVA training↗

Status and specifications of a Project X front-end accelerator test facility at Fermilab

This paper describes the construction and operational status of an accelerator test facility for Project X. The purpose of this facility is for Project X component development activities that benefit from beam tests and any development activities that require 325 MHz or 650 MHz RF power. It presently includes an H- beam line, a 325 MHz superconducting cavity test facility, a 325 MHz (pulsed) RF power source, and a 650 MHz (CW) RF power source. The paper also discusses some specific Project X components that will be tested in the facility. Fermilab's future involves new facilities to advance the intensity frontier. In the early 2000's, the vision was a pulsed, superconducting, 8 GeV linac capable of injecting directly into the Fermilab Main Injector. Prototyping the front-end of such a machine started in 2005 under a program named the High Intensity Neutrino Source (HINS). While the HINS test facility was being constructed, the concept of a new, more versatile accelerator for the intensity frontier, now called Project X, was forming. This accelerator comprises a 3 GeV CW superconducting linac with an associated experimental program, followed by a pulsed 8 GeV superconducting linac to feed the Main Injector synchrotron. The CW Project X design is now the model for Fermilab's future intensity frontier program. Although CW operation is incompatible with the original HINS front-end design, the installation remains useful for development and testing many Project X components.

43 PARTICLE ACCELERATORS↗

FACET: The New User Facility at SLAC

FACET (Facility for Advanced Accelerator and Experimental Tests) is a new User Facility at SLAC National Accelerator Laboratory. Its high power electron and positron beams make it a unique facility, ideal for beam-driven Plasma Wakefield Acceleration studies. The first 2 km of the SLAC linac produce 23 GeV, 3.2 nC electron and positron beams with short bunch lengths of 20 {mu}m. A final focusing system can produce beam spots 10 {mu}m wide. User-aided Commissioning took place in summer 2011 and FACET will formally come online in early 2012. We present the User Facility, the current features, planned upgrades and the opportunities for further experiments. Accelerators are our primary tool for discovering the fundamental laws to the universe. Each new frontier we probe requires a new, more powerful method. Accelerators are therefore increasing in size and cost. The future of this field requires new accelerating techniques that can reach the high energies required over shorter distances. New concepts for high gradient acceleration include utilizing the wakes in plasma and dielectric and metallic structures. FACET was built to provide a test bed for novel accelerating concepts with its high charge and highly compressed beams. As a test facility unlike any other, it has also attracted groups interested in beam diagnostic techniques and terahertz studies. The first phase of the construction was completed in May 2011. Beam commissioning began in June and was interleaved with the installation of five experiments. Users were invited to aid with the commissioning for the month of August during which time experimental hardware and software were checked out and some first measurements were taken. FACET is currently in the process of becoming a Department of Energy User Facility for High Energy Physics.

43 PARTICLE ACCELERATORS↗

Status and Plans for a Superconducting RF Accelerator Test Facility at Fermilab

The Advanced Superconducting Test Accelerator (ASTA) is being constructed at Fermilab. The existing New Muon Lab (NML) building is being converted for this facility. The accelerator will consist of an electron gun, injector, beam acceleration section consisting of 3 TTF-type or ILC-type cryomodules, multiple downstream beam lines for testing diagnostics and conducting various beam tests, and a high power beam dump. When completed, it is envisioned that this facility will initially be capable of generating a 750 MeV electron beam with ILC beam intensity. An expansion of this facility was recently completed that will provide the capability to upgrade the accelerator to a total beam energy of 1.5 GeV. Two new buildings were also constructed adjacent to the ASTA facility to house a new cryogenic plant and multiple superconducting RF (SRF) cryomodule test stands. In addition to testing accelerator components, this facility will be used to test RF power systems, instrumentation, and control systems for future SRF accelerators such as the ILC and Project-X. This paper describes the current status and overall plans for this facility.

43 PARTICLE ACCELERATORS↗

Advanced Test Reactor National Scientific User Facility: Addressing advanced nuclear materials research

The Advanced Test Reactor National Scientific User Facility (ATR NSUF), based at the Idaho National Laboratory in the United States, is supporting Department of Energy and industry research efforts to ensure the properties of materials in light water reactors are well understood. The ATR NSUF is providing this support through three main efforts: establishing unique infrastructure necessary to conduct research on highly radioactive materials, conducting research in conjunction with industry partners on life extension relevant topics, and providing training courses to encourage more U.S. researchers to understand and address LWR materials issues. In 2010 and 2011, several advanced instruments with capability focused on resolving nuclear material performance issues through analysis on the micro (10-6 m) to atomic (10-10 m) scales were installed primarily at the Center for Advanced Energy Studies (CAES) in Idaho Falls, Idaho. These instruments included a local electrode atom probe (LEAP), a field-emission gun scanning transmission electron microscope (FEG-STEM), a focused ion beam (FIB) system, a Raman spectrometer, and an nanoindentor/atomic force microscope. Ongoing capability enhancements intended to support industry efforts include completion of two shielded, irradiation assisted stress corrosion cracking (IASCC) test loops, the first of which will come online in early calendar year 2013, a pressurized and controlled chemistry water loop for the ATR center flux trap, and a dedicated facility intended to house post irradiation examination equipment. In addition to capability enhancements at the main site in Idaho, the ATR NSUF also welcomed two new partner facilities in 2011 and two new partner facilities in 2012; the Oak Ridge National Laboratory, High Flux Isotope Reactor (HFIR) and associated hot cells and the University California Berkeley capabilities in irradiated materials analysis were added in 2011. In 2012, Purdue University’s Interaction of Materials with Particles and Components Testing (IMPACT) facility and the Pacific Northwest Nuclear Laboratory (PNNL) Radiochemistry Processing Laboratory (RPL) and PIE facilities were added. The ATR NSUF annually hosts a weeklong event called User’s Week in which students and faculty from universities as well as other interested parties from regulatory agencies or industry convene in Idaho Falls, Idaho to see presentations from ATR NSUF staff as well as select researchers from the materials research field. User’s week provides an overview of current materials research topics of interest and an opportunity for young researchers to understand the process of performing work through ATR NSUF. Additionally, to increase the number of researchers engaged in LWR materials issues, a series of workshops are in progress to introduce research staff to stress corrosion cracking, zirconium alloy degradation, and uranium dioxide degradation during in-reactor use.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Evaluation of irradiation facility options for fusion materials research and development

Successful development of fusion energy will require the design of high-performance structural materials that exhibit dimensional stability and good resistance to fusion neutron degradation of mechanical and physical properties. The high levels of gaseous (H, He) transmutation products associated with deuterium-tritium (D-T) fusion neutron transmutation reactions, along with displacement damage dose requirements up to 50-200 displacements per atom (dpa) for a fusion demonstration reactor (DEMO), pose an extraordinary challenge. The intense neutron source(s) is needed to address two complimentary missions: 1) Scientific investigations of radiation degradation phenomena and microstructural evolution under fusion-relevant irradiation conditions (to provide the foundation for designing improved radiation resistant materials), and 2) Engineering database development for design and licensing of next-step fusion energy machines such as a fusion DEMO. A wide variety of irradiation facilities have been proposed to investigate materials science phenomena and to test and qualify materials for a DEMO reactor. Currently available and proposed facilities include fission reactors (including isotopic and spectral tailoring techniques to modify the rate of H and He production per dpa), dual- and triple-ion accelerator irradiation facilities that enable greatly accelerated irradiation studies with fusion-relevant H and He production rates per dpa within microscopic volumes, D-Li stripping reaction and spallation neutron sources, and plasma-based sources. The advantages and limitations of the main proposed fusion materials irradiation facility options are reviewed. Evaluation parameters include irradiation volume, potential for performing accelerated irradiation studies, capital and operating costs, similarity of neutron irradiation spectrum to fusion reactor conditions, temperature and irradiation flux stability/control, ability to perform multiple-effect tests (e.g., irradiation in the presence of a flowing coolant, or in the presence of complex applied stress fields), and technical maturity/risk of the concept. Ultimately, it is anticipated that heavy utilization of ion beam and fission neutron irradiation facilities along with sophisticated materials models, in addition to a dedicated fusion-relevant neutron irradiation facility, will be necessary to provide a comprehensive and cost-effective understanding of anticipated materials evolution in a fusion DEMO and to therefore provide a timely and robust materials database.

embrittlement↗

EFFECT OF INCLINED WAVES ON DEEPLY EMBEDDED NUCLEAR FACILITIES

Several conceptual designs for advanced reactors show that most if not all of the structure is embedded in the soil. Consequently, analysis techniques that have been verified and validated for the analysis of light water reactors on surface foundations may not be directly applicable to deeply embedded reactors. Specifically two effects that may change the in-structure response (ISR) of embedded facilities are: (i) the effect of the kinematic interaction becomes more prominent as the embedment depth increases; (ii) non-vertically propagating waves, which are usually not considered for surface-founded facilities, may be more important for deeply embedded facilities. A preliminary study is presented in this article to understand the response of embedded nuclear facilities to non-vertically propagating seismic waves. The inclined wave field is generated from source-to-site simulations using representative earthquake faults with different dip angles. The embedment depth of the nuclear containment facility is also varied to obtain a better understanding of the effect of embedment. This analysis of the soil-structure ensemble is conducted using the application called Multi-hazard Analysis for STOchastic time-DOmaiN phenomena (MASTODON), developed on top of Idaho National Lab’s open source MOOSE finite element framework. The Domain Reduction Method implemented in MASTODON to incorporate the seismic excitation within the region of interest is verified and then used to reduce the computational effort in analyzing this problem. Preliminary analysis using linear soil and structure material properties and tied contact between the soil and structure indicate that embedding the nuclear facility reduces significantly the response of the structure in all the earthquake scenarios considered.

42 ENGINEERING↗

The Fermilab Test Beam Facility Data Acquisition System Based on $otsdaq$

The Real-Time Systems Engineering Department of the Scientific Computing Division at Fermilab has deployed set of customizations to our Off-The-Shelf Data Acquisition solution (otsdaq) at the Fermilab Test Beam Facility (FTBF) to read out the beamline instrumentation in support of FTBF users. In addition to reading out several detectors which use various detection technologies and readout hardware, the FTBF Data Acquisition system (DAQ) can perform basic track reconstruction through the facility in real time and provide data to facility users. An advanced prototype smart coincidence module, known as the NIM+, performs trigger distribution and throttling, allowing the beamline instrumentation to be read out at different rates. Spill data are saved to disk for studies of the facility performance, and hit data are also made available on the FTBF network for experiments' use. A web-based run control and configuration GUI are provided, and the online monitoring snapshots created after each beam spill are viewable from any computer connected to the Fermilab network. The integrated DAQ system for the facility provides users with high-precision tracking data along the beamline and a single location for obtaining data from the facility detectors, which set the baseline for testing their own detectors.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

FEMP Facility Evaluation (Audit) Decision Tree

This document is a resource to be used in concert with FEMP Audit Definitions, FEMP Consolidated Facility Management Guidance, and agency best practices and expert judgment—for agencies to use to determine the best approaches to evaluate their facilities. It features a decision tree that provides a framework for agencies to interpret gathered facility data to understand the existing conditions; benchmark the facility against others in the portfolio to determine whether an on-site or remote audit is appropriate for a facility; determine the best remote or on-site audit level of detail to meet agency facility auditing goals, such as meeting Energy Independence and Security Act of 2007 requirements and developing projects; and improve their energy and water management programs.

auditing↗

Comparison of Calculated and Experimental Results for a Boiling/Condensing Experimental Facility

A new experimental facility is being developed for materials irradiation and testing at the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR). Details of this facility have been presented before. A prototype of this facility, the Thermosyphon Test Loop (TSTL) has been built, and experimental data have been obtained and analyzed. Pretest calculations for this facility with the RELAP5-3D code have been presented previously as well as other calculations with the TRACE code. The results of both codes were very different. RELAP5-3D predicted much higher pressures and temperatures than TRACE. This paper compares calculated results with the TSTL experimental data. Comparison of calculations with the codes RELAP5-3D and TRACE with experimental data of the new TSTL facility has shown that TRACE results agree well with the data and that RELAP5-3D calculates very high pressures and temperatures. The TRACE code is well suited to model this facility and is being used for future calculations. (authors)

42 ENGINEERING↗

Computer Security for I and C Systems at Nuclear Facilities - 116

Cyber-attacks on Instrumentation and Control (I and C) systems may jeopardize the safety and security of nuclear facilities by contributing to sabotage or aiding in the unauthorized removal of nuclear material. The effects of cyber-attacks on I and C systems important to safety to safety may result in a wide range of consequences, such as a temporary loss of process control or unacceptable radiological consequences. Public awareness of cyber-attacks that affect I and C systems may also undermine confidence in the safety and security of nuclear facilities. The International Atomic Energy Agency (IAEA) recognizes the need for the guidance on the protection of I and C systems that provide safety, security, or auxiliary functions at nuclear facilities from cyber-attacks. To meet this need, The IAEA has developed a new Nuclear Security Series publication with the provisional title Computer Security of Instrumentation and Control Systems at Nuclear Facilities which builds upon and expands the guidance published in Nuclear Security Series No. 17 Computer Security at Nuclear Facilities (2011) . This publication will be formally released in 2017 as Technical Guidance and will be the second international consensus publication dedicated to Computer Security at Nuclear Facilities. It was developed in parallel with the new IAEA Nuclear Safety publications providing recommendations on I and C systems at research reactors (RR) and nuclear power plants (NPP) . The purpose of this paper is to provide an overview of this publication and its application. The paper will also discuss its relation to other IAEA Nuclear Security Series (NSS) publications on computer security. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Progress Towards the Validation of a new RELAP5-3D model of the High Temperature Test Facility

Validation is a key step in the development of any type of systems model. As the next generation of reactors approaches, the need for codes that have been validated for these new types of systems continues to grow. An example of a prominent option is the Reactor Excursion Leak Analysis Program (RELAP5-3D), developed by Idaho National Laboratory. This code was developed for the purpose of systems level thermal-hydraulic modeling of light water reactors (LWRS) and postulated transients that can occur in LWRS.RELAP5-3D has been substantially validated against LWR data. Due to its long history as a reactor safety analysis tool, there has been an effort to adapt RELAP5-3D for the purposes of advanced reactor concepts such as prismatic high-temperature gas-cooled reactors (HTGRs). However, RELAP5-3D has not nearly been validated and verified for HTGRs to the degree of LWRs, warranting verification and validation opportunities with computational benchmarks and existing experimental facilities. Examples of such facilities include the modular high-temperature gas-cooled reactor (MHTGR) 350 and the high temperature engineering test reactor (HTTR) from Japan. The MHTGR 350 is a benchmark design concept for code-to-code verification purposes; therefore, it does not provide any experimental data for validation opportunities The HTTR provides useful multiphysics validation data but does not have the in-core instruments to generate thermal-hydraulic experimental data to help with RELAP5-3D validation. Consequently, a facility that could provide key in-core temperatures for thermal-hydraulic validation was still needed. The High Temperature Test Facility (HTTF) is an integral effects facility for HTGR thermal hydraulics developed and operated by Oregon State University. HTTF represents ¼ length scale of the General Atomics MHTGR and is rated for a total power of 2.2 MW. Axially, the core consists of an upper and lower reflector and 10 blocks, numbered from bottom to top (Block 1 is right above lower reflector). The core is heated via graphite resistive heater rods, with respective channels distributed throughout the core. The primary coolant is helium and heat can radiate out of the core to the reactor cavity cooling system (RCCS), which is cooled by water. The primary purpose of the facility is to investigate pressurized conduction cooldown (PCC) and depressurized conduction cooldown (DCC) transients, which are also referred to as the pressurized and depressurized loss of forced cooling respectively. Two experiments were chosen to perform the validation study with a RELAP5-3D model of HTTF. These experiments are PG-27 (PCC) and PG-29 (DCC). These were chosen based off of the quality of available experimental data before and during the experiment which led to their inclusion in the HTGR Thermal Hydraulics Benchmark.

22 - GENERAL STUDIES OF NUCLEAR REACTORS↗

Gas migration in low- and intermediate-level waste (LILW) disposal facility in Korea

The first low- and intermediate-level waste (LILW) disposal facility is under construction in saturated granite in Korea. The safety assessment report (SAR) identified that different gases, such as hydrogen, carbon dioxide, and methane are generated at the disposal facility due to the corrosion of metal wastes and steel drum, and microbial degradation of organic matters. Reinforced concrete plays a role as an engineered barrier at the disposal facility, so its properties with regard to gas migration were evaluated in laboratory-scale experiments. Then modeling of gas migration was carried out to evaluate gas pressure build-up in the disposal facility. The gas entry pressure and relative gas permeability of the concrete was determined to be 0.97±0.15 bar, and the relative gas permeability decreased exponentially with increasing water content. The results of the modeling showed that most of hydrogen gas was dissolved in groundwater and did not significantly influence pressure build-up inside the disposal facility based on the reference case of gas generation. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Evaporation Of Hanford Waste Treatment Plant Direct Feed Low Activity Waste Effluent Management Facility Core Simulant

The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Melter Off-Gas Condensate, LMOGC) from the off-gas system. The baseline plan for disposition of this stream during full WTP operations is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation, and recycled to the LAW vitrification facility. However, during the Direct Feed LAW (DFLAW) scenario, planned disposition of this stream is to evaporate it in a new evaporator, in the Effluent Management Facility (EMF), and then return it to the LAW melter. It is important to understand the composition of the effluents from the melter and new evaporator, so that the disposition of these streams can be accurately planned and accommodated. Furthermore, alternate disposition of the LMOGC stream would eliminate recycling of problematic components, and would reduce the need for closely integrated operation of the LAW melter and the Pretreatment Facilities. Long-term implementation of this option after WTP start-up would decrease the LAW vitrification mission duration and quantity of glass waste, amongst the other operational complexities such a recycle stream presents. In order to accurately plan for the disposition path, it is key to experimentally determine the fate of contaminants. To do this, testing is needed to accurately account for the buffering chemistry of the components, determine the achievable evaporation end point, identify insoluble solids that form, and determine the distribution of key regulatory-impacting constituents. The LAW Melter Off-Gas Condensate stream will contain components that are volatile at melter temperatures, have limited solubility in the glass waste form, and represent a materials corrosion concern, such as halides and sulfate. Because this stream will recycle within WTP, these components will accumulate in the Melter Condensate stream, exacerbating their impact on the number of LAW glass containers that must be produced. Diverting the stream reduces the halides and sulfates in the recycled Condensate and is a key outcome of this work. This overall program examines the potential treatment and immobilization of this stream to enable alternative disposal. The objective of this task was to demonstrate evaporation of a simulant of the LAW Melter Off-gas Condensate expected during DFLAW operations, in order to predict the composition of the effluents from the EMF evaporator to aid in planning for their disposition. This document describes the results of that test using the core simulant. This simulant formulation is designated as the “core simulant”; other additives will be included for specific testing, such as volatiles for evaporation or hazardous metals for measuring leaching properties of waste forms. The results indicate that the simulant can easily be concentrated via evaporation. During that the pH adjustment step in simulant preparation, ammonium is quickly converted to ammonia, and most of the ammonia was stripped from the simulated waste and partitioned to the condensate. Additionally, it was found that after concentrating (>12x) and cooling that a small amount of LiF and Na 3 (SO 4 )F precipitate out of solution. With the exception of ammonia, analysis of the condensate indicated very low to below detectable levels of many of the constituents in the simulant, yielding very high decontamination factors (DF).

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗