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NSR&D Program Funded Projects

NSRD-01, Develop and Manufacture an Ergonomically Sound Glovebox Glove

Principle Investigator:  Cindy Lawton, Board Certified Ergonomist,

Objective:  Design and develop a safer and more ergonomic glovebox glove. Partner with a manufacturer for large-scale production of the glove that can be integrated into gloveboxes throughout the DOE complex.

Technical Approach:  The approach to develop a new glovebox glove began with an extensive understanding of hand anatomy and anthropometrics, as well as an in-depth literature review of glove development for other industries, such as the National Aeronautics and Space Administration. Utilizing this data, along with collaboration with an orthopedic hand surgeon, the new glovebox glove dimensions were determined. Next, we developed the ability to input the glove/hand dimension information into a 3D engineering program. Last, workers tested the new glove dimensions for validity. The new ergonomic glove design has received a patent. The final two stages of this project are to bring this new technology to a glove manufacturer for production and, once made, testing the new glove for improved dexterity and comfort at two different DOE sites.

Benefits:  This new design will be of great benefit since there are no suitable commercially available options to replace the current Los Alamos National Laboratory (LANL) glovebox glove, whose mold dates back to the 1960s.  An improved glovebox glove will have three significant benefits:  1) it will reduce the risk of injury, 2) it will improve comfort and productivity for the workers, and 3) it will reduce the risk of glovebox breaches.  The estimated savings from combination of these three benefits are several million dollars.

Status:  As a result of funding from the fiscal year 2013 NSR&D Program, the new ergonomic glove dimensions have been established and input into a 3D model. The dimensions have been verified with the glovebox workers. The LANL technical transfer organization is in the final stages of negotiating a contract agreement with Honeywell, Inc., which produces most glovebox gloves for the DOE complex.  LANL purchases approximately $500,000 in glovebox gloves yearly from Honeywell. The development phase of the project is complete and the manufacturing phase is in process. Ultimately, the project will lead to improved safety and efficiency, a decrease in injuries and glove breaches, and a significant cost savings throughout the DOE complex.

NSRD-02, In-Place Filter Testing Instrument for Nuclear Material Containers

Principle Investigator:  Murray E. Moore,

Objective:  The objective of this project is to develop a small (portable) desktop instrument to assess operational conditions of nuclear material storage containers without disassembling the containers. The instrument would determine if the high-performance filter on the storage container is clogged. Additionally, the instrument would determine if the container O-ring seal is air-tight, or if the O-ring seal has failed.

Technical Approach:  The project is developing a methodology to simulate failure conditions, procure a set of standard test filters and canisters, and define test criteria that are appropriate to storage canister operations. The testing is being conducted on two types of nuclear material storage containers. The first is the commonly used Hagan canister with three different sizes tested (5, 8 and 12 quart), and the second is the new SAVY canister being designed for use throughout the DOE complex (only the 5 quart size canister).

Benefits:  The DOE complex will benefit in regard to personnel safety and facility operations if an IPFT (in-place filter test) capability is implemented. Filter integrity assessment would indicate whether the filter was plugged or operating within an acceptable performance range. A canister could be verified for leak-tightness, either after canister packaging, or by testing the as-found condition. Additionally, a set of standard filters and a method to define and maintain them would be indispensable for filter integrity assessment.

Status:  The Los Alamos Aerosol Engineering Facility developed a prototype In-Place Filter Testing Instrument (IPFT) device. The prototype is a microprocessor-controlled system that applies a slight vacuum to an assembled nuclear material storage canister (e.g., 0.2 psi of vacuum compared to 14.7 psi atmospheric pressure). The prototype system was used to identify flow and pressure parameters for testing actual canisters. Stainless steel fittings were custom-designed and built for a direct leak-test interface for the nuclear storage canisters, and a set of tests performed with actual canisters. The prototype work defined a set of parameters which were used specify the performance variables for a customized leak test system (the Isaac™ from Zaxis).  Testing with the Isaac system is nearing completion and the project is currently developing the final report to communicate the results of the project.

NSRD-03, Ceramic HEPA Filters

Principle Investigator:  Mark Mitchell,

Objective:  The technical objective of this project is to develop and deploy advances in HEPA filter technology (e.g., related to ceramic HEPA filters) to benefit DOE nuclear facilities by providing lower life-cycle costs and reducing or eliminating certain safety basis costs associated with safety class and safety significant systems in nuclear facilities. This project is broken into two main tasks. First, perform high temperature testing on HEPA filter materials and components at Cal Poly’s High Temperature Testing Unit (HTTU). Second, develop qualification testing standards for ceramic HEPA filters at Mississippi State’s Institute for Clean Energy Technology (ICET). Lawrence Livermore National Laboratory (LLNL) is the lead for the activity and collaborates with both universities.

Technical Approach:  The goal of this project is to support development and deployment of advanced HEPA filter technology by enabling testing to support the understanding, selection, and optimization of materials under key conditions (e.g., fires in a nuclear facility) and to support the development of test setups and specifications for industry codes and standards (e.g., ASME AG-1 Subsection FO Ceramic Filters). The first effort utilizes the unique capabilities of the HTTU to test new and innovative materials for HEPA filter components (e.g., media, sealants, gaskets). The second effort will use the DOE-sponsored ICET and HTTU as they relate to the development of test setups and specifications for industry codes and standards.

Benefits:  This research has the potential to benefit the nuclear facilities of DOE, including the NNSA, by significantly lowering life-cycle costs, including decreasing design and operational costs associated with safety class or safety significant ventilation systems and components.  Qualifying the performance of ceramic filters in a fire could also significantly reduce or eliminate safety basis costs of support systems associated with mitigating a release. This could save DOE $1M to $10M annually, and potentially much more. There is a significant design and operational cost savings associated with using normal life and property protection requirements, as opposed to requirements for safety class or safety significant systems with NQA-1, configuration management, and the USQ process. Simplifying facility behavior in fire scenarios could significantly cut modeling and analysis costs for nuclear facility Documented Safety Analyses (DSA). It is advantageous to DOE to focus fundamental research and development on engineering safety solutions (hardware) rather than additional analysis. Through longer filter life, DOE could save more than $11M annually related to reductions in waste disposal costs alone. The lifecycle cost of a HEPA filter in a DOE nuclear facility is driven mostly by the cost of disposing of radioactively contaminated HEPA filters, not the price of the filter itself.

Status:  The ceramic test stand Technical Working Group (TWG) was established, with members from ICET, LLNL, the NSR&D Program, and the ASME AG-1 Subsection FO writing team. ICET gave a presentation on the ceramic test stand and its capabilities to the TWG. Preliminary tests will be conducted to down-select the seals, gaskets, media, and materials; and the most promising will be tested at full-scale conditions in the HTTU. The first Cal Poly student team completed its rapid prototype testing system (Mini-HTTU) for preliminary tests on a large number of material samples. The second Cal Poly student team presented its final design for the rapid change out sample chamber and preliminary material selection.

NSRD-04, Study of HEPA Filter Degradation Due to Aging

Principle Investigator:  Elaine Diaz, P.E.,

Objective:  High efficiency particulate air (HEPA) filters are credited as the final barrier against release of radioactive contamination in nearly every operating US Department of Energy (DOE) and National Nuclear Security Administration (NNSA) nuclear facility. Approximately 6000 HEPA filters are purchased each year within the DOE/NNSA complex. Each of these filters is tested, inspected, stored in special environmental conditions until needed. When needed, they are installed, tested post-installation, in-place leak tested annually, removed, and disposed of through a rigorous procedure designed to ensure integrity of these crucial, yet fragile, components. Filter aging leads to degradation of tensile strength across the face of filter media pleats. The key mechanisms suspected in filter aging are environmental conditions in storage or in use, such as humidity, temperature, oxidation, and pleat flutter. These issues have been discussed at length without sufficient data to provide definitive conclusions.

Concerns and uncertainty associated with degradation of HEPA filter performance over time led DOE sites to limit HEPA filter service life to 10 years from date of manufacture.This policy causes hundreds of otherwise unnecessary filter changes, putting employees at risk of exposure, causing facility operational disruptions, causing otherwise compliant filters to be disposed without being used due to expiring service life, and costing DOE millions of dollars annually. Conclusive data are needed to resolve uncertainty associated with the damaging effects of aging on durability of HEPA filters.

Testing will compare performance and durability under upset or design basis conditions of new filters, as well as filters retained in storage for ten to twenty years (past current service life). Testing will evaluate the effects of flutter/vibration, which may cause fatigue failure of filter pleats, and is suspected to be a leading cause of filter “aging” when installed in operating plants. These data are necessary to determine the envelope within which nuclear safety experts can credit HEPA filter performance as an accident control, leading to establishment of a risk-informed DOE service life.

Technical Approach:  The Mississippi State University (MSU) Institute for Clean Energy Technology (ICET) is a center of excellence for HEPA filter testing. The MSU ICET full-scale HEPA test stand has been used in past testing to challenge filters under simulated accident conditions. The technical approach for this research involves bench scale and full-scale tests of aged and new HEPA media and filters for comparison. A technical working group composed of industry and DOE complex subject matter experts will guide detailed test planning and oversee progress.

Benefits:  A deeper understanding of the effects of aging and fatigue on HEPA filter performance will help DOE define a service life for these fragile components that minimizes risk, while possibly reducing costs and work necessary to maintain these systems. There is potential cost savings to the government, as well as avoidance of operational impact and reduction of radiation exposure for DOE’s facility workers, if data supports extending HEPA shelf life and change-out intervals.

NSRD-05, Development and validation of methodology to model flow in ventilation systems commonly found in nuclear facilities

Principle Investigator:  James Bailey, Ph. D., P. E.,

Objective:  It is known that multiple sites across the DOE complex take credit for hot cells, gloveboxes, and/or hoods in their safety basis for providing a defense-in-depth benefit for both onsite and offsite releases. By providing confinement of radioactive materials, such features serve to reduce direct doses to facility workers and mitigate the consequences to the environment due to an uncontrolled release. Each of these features has access points that interface with the personnel space. Understanding how air flow behaves at these access points is of great interest to those performing hazard analyses.

Argonne National Laboratory has recently started applying Computational Fluid Dynamics (CFD) to analyze and model the flows in hot cells and glove boxes as a way to confirm operation. While CFD capability continues to advance, there are still important modeling assumptions that are left to the analyst’s discretion. These are most notably the choice of the turbulence models, mesh structure, and wall boundary condition assumptions used in the model. The modeling assumptions have a profound impact on the analysis result and it is the purpose of this proposal to determine and validate proper choices through an iterative analysis/validation process.

Technical Approach:  In this work, the project will apply the CFD experience gained in modeling airflow in these areas to the problem of modeling air flow and particulate transport. These studies will include a specifically selected set of standard geometries commonly found in glovebox and hot cell facilities. This modeling will be supported by field measurement studies which will both inform and validate the modeling assumptions. Based on the results of field tests, the project will refine the modeling assumptions and boundary conditions and repeat the process until the results are found to be reliable with a high level of confidence.

Benefits:  The main outcome of this project is the development of a methodology for using CFD to analyze the glovebox and hot cell installations. This methodology will include the modeling assumptions for a variety of typical configurations that were arrived at through the iterative modeling and validation procedure described above. Having such a methodology will provide guidance to other analysts and reduce uncertainty. It will also remove or reduce the need for further validation. Further, this methodology will also be beneficial to designers of glovebox and hot cell facilities.

NSRD-06, Computational Capability to Substantiate DOE-HDBK-3010 Data

Principle Investigator:  David L.Y. Louie,

Objective:  Safety basis analysts throughout the DOE complex rely heavily on the information provided in DOE Handbook 3010, Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities to determine source terms. Most often, the analysts simply take the bounding values because time constraints and to avoid regulatory critique. Although the Handbook is comprehensive in terms of data to derive airborne release fractions and respirable fractions to bound the main types of accidents that could be encountered in the complex, the derivation of the data often depended on table-top and bench/laboratory experiments, as well as engineering judgment which may not be substantiated and may not be representative to the actual situation. The goal of this research is to provide a more accurate method to identify bounding values for the Handbook. The advancement in computing capabilities at national laboratories allows the use of code simulation methods to provide more representative values for the source term.

Technical Approach:  This research should provide insights about the fundamental physics and phenomena associated with the types of accidents, based on the maturity of the simulation tools developed for the weapons complex. Although these tools require intense computational power, the availability of these tools and computing power allows safety analysts to utilize them for non-weapons related safety activities. These simulation tools will be used to assess whether the data used to derive the airborne release fractions and respirable fractions in the Handbook are reasonably accurate and bounding.

Benefits:  If the reduced-scale data are conservative, the source term used for the documented safety analyses may over-specify the need for design controls. This over-specification could substantially be a cost to DOE/NNSA. If the data are non-conservative, the documented safety analysis may underestimate the source term, which could translate to a significant safety concern for the workers and public. In either case, the results of the research may improve how the safety basis analysts across the complex approach the selection of bounding airborne release fractions and respirable fractions, which can result in improving the defensibility of the safety analyses.

NSRD-07, Stochastic Modeling of Radioactive Material Releases

Principle Investigator:  Jason Andrus,

Objective:  Traditional radioactive material release modeling codes generally provide a bounding single point estimate of receptor dose using point value input parameters and a straight-line Gaussian plume dispersion model. However, this approach can fall short since it tends to provide bounding dose estimates rather than a dose distribution with quantification of the dose uncertainty. This is particularly problematic when one considers the impact of governing distributions for input variables such as material-at-risk, damage ratio, airborne release fraction, respirable fraction, leak path factor, breathing rate, and even dose conversion factors. Additionally, although the atmospheric dispersion model is based on a Gaussian distribution, stochastic sampling of the distribution is typically not used to reach the dose estimate. Thus, decisions regarding potential doses to members of the public are frequently overstated, leading to excessively conservative material-at-risk limits and potential over selection of safety systems structures, or components. To address this issue, a Monte Carlo-based code system is proposed to stochastically analyze radiological material release scenarios and provide dose distribution estimates. This approach will support improved risk understanding, leading to better-informed decision making associated with establishing material-at-risk limits and safety system, structure or component selection. It is important to note that this project is not intended to replace or compete with codes such as MACCS or RSAC; rather it is viewed as an easy to use supplemental tool to help improve risk understanding and support better-informed decisions.

Technical Approach:  The code system will be developed using MATLAB, and will incorporate widespread use of Monte Carlo methods, as well as a graphical user interface for ease of operation. Monte Carlo techniques will include user selection of the governing distribution for such input parameters as the material-at-risk, damage ratio, airborne release fraction, respirable fraction, leak path factor, breathing rate, and dose conversion factors. Once the code system is developed, bounding value dose results will be benchmarked using traditional radioactive material release modeling codes such as MACCS or RSAC. Systematic investigation of each parameter contributing to the dose result will be pursued to quantify the parameter’s contribution to the overall dose estimate and uncertainty. The process will be carried out for a suite of disruptive scenarios. Systematic study of each contributing parameter will lead to identification of the parameters that have the largest impact on the resulting dose estimate uncertainty. Once identified, investigation into reducing uncertainty in the key parameters can be accomplished.  The project will initially be dedicated to distribution research, code construction, and testing of the code system. The code system will be distributed to select organizations for beta-testing and feedback. A follow-on proposal will be pursued to apply the necessary quality assurance to transition the code from research and development status to one that can be included as a field-useable toolbox code.

Benefits:  The most important benefit associated with this project will be improved risk understanding. Contractors and approval authority personnel will be able to make better-informed decisions by being able to compare dose estimate results that include a more systematic quantification of the impact of contributors to the dose estimate with the currently used highly conservative methods. This will allow for risk-informed decisions related to areas where use of alternative methods may justify significant cost savings without reduction in safety.