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DOE OSTI2020

Embedded fiber optic cables for battery management

A battery includes a folded bicell battery stack with an embedded fiber optic cable and sensor. A cell casing encloses the bicell stack with at least one fiber optic cable is embedded within the battery. The fiber optic cable includes an internal portion disposed within the cell casing and having at least one optical sensor disposed thereon. An external portion of the fiber optic cable protrudes from the casing. A sealing gasket is disposed at least partially around the fiber optic cable and between the cell sealing edges at a point of entry of the fiber optic cable into the battery.

25 ENERGY STORAGE↗

DOE OSTI2022

Microwatt fuel cell stack

A microwatt fuel cell stack that demonstrates a wide range temperature tolerance, low reactant cross-over and leakage, low internal leakage current, and/or effective water transport is disclosed. Both H 2 and O 2 may be supplied directly to the fuel cell stack (i.e., dead-ended). One-piece gas diffusion electrodes (GDEs) may serve as both the active electrode and manifold port. Water removal may be accomplished by permeation through the membrane to “fins” exposed by notches in the bipolar plates and gaskets.

Wilson, Mahlon Scott↗

DOE OSTI2013

Pressure Build-Up During the Fire Test in Type B(U) Packages Containing Water - 13280

The safety assessment of packages for the transport of radioactive materials with content containing liquids requires special consideration. The main focus is on water as supplementary liquid content in Type B(U) packages. A typical content of a Type B(U) package is ion exchange resin, waste of a nuclear power plant, which is not dried, normally only drained. Besides the saturated ion exchange resin, a small amount of free water can be included in these contents. Compared to the safety assessment of packages with dry content, attention must be paid to some more specific issues. An overview of these issues is provided. The physical and chemical compatibility of the content itself and the content compatibility with the packages materials must be demonstrated for the assessment. Regarding the mechanical resistance the package has to withstand the forces resulting from the freezing liquid. The most interesting point, however, is the pressure build-up inside the package due to vaporization. This could for example be caused by radiolysis of the liquid and must be taken into account for the storage period. If the package is stressed by the total inner pressure, this pressure leads to mechanical loads to the package body, the lid and the lid bolts. Thus, the pressure is the driving force on the gasket system regarding the activity release and a possible loss of tightness. The total pressure in any calculation is the sum of partial pressures of different gases which can be caused by different effects. The pressure build-up inside the package caused by the regulatory thermal test (30 min at 800 deg. C), as part of the cumulative test scenario under accident conditions of transport is discussed primarily. To determine the pressure, the temperature distribution in the content must be calculated for the whole period from beginning of the thermal test until cooling-down. In this case, while calculating the temperature distribution, conduction and radiation as well as evaporation and condensation during the associated process of transport have to be considered. This paper discusses limiting amounts of water inside the cask which could lead to unacceptable pressure and takes into account saturated steam as well as overheated steam. However, the difficulties of assessing casks containing wet content will be discussed. From the authority assessment point of view, drying of the content could be an effective way to avoid the above described pressure build-up and the associated difficulties for the safety assessment. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2016

Perspective of Dry Interim Storage of spent nuclear fuel (SNF) in Germany - 16504

According to article 6 of the German Atomic Energy Act, storage of nuclear fuel requires a license granted by the competent authority in this field, which is the Federal Office of Radiation Protection (BfS). In 1995 a license to store spent nuclear fuel (SNF) and vitrified high level waste (HAW) for the interim storage facility in Gorleben was granted. Dry Interim storage at the NPP sites in its current form started in 2002 in the interim storage facility next to the NPP Lingen. Since this time each NPP erected its own storage facility and three central storage facilities have been built. All of these facilities use dry storage in metallic dual purpose casks (DPCs). The actual storage licenses for SNF and the HAW (which is stored in Gorleben and Rubenow) are limited to 40 years after closing the transport and storage cask. The first license to expire will be the storage license for the interim storage facility in Gorleben in the year 2035. During the last two years in Germany preparatory consultations to restart the process towards finding a repository took place, organised by a commission. This commission consists out of members of the scientific community, religious parties, social communities and environmental organizations as well as members of federal states governments and members of the German parliament (Bundestag). Recently the commission decided to extend its working period until summer 2016. Taking this background into account the BfS plans to intensify its research into extended interim storage with respect to potential material degradation leading to interference with safety functions (e.g. neutron shielding material). This includes topics like ageing of gasket materials which are already studied in ongoing experiments (e.g. at the Federal Institute for Materials Research and Testing) as well as studies of long term relaxation processes. Because of the need for transportation towards a repository another important field is the behaviour of the inventory under mechanical loads. For SNF, first calculations showed that because of the lower decay heat load after 60 years due to hydride reorientation the cladding might become much less ductile. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2018

Modeling of Lead-210 Data Documents Benefits in Proactively Understanding TENORM Deposition - 18515

Radioactive decay of naturally occurring Radon-222 present in just-produced natural gas can lead to deposition of its radiogenic daughter, Lead-210, and subsequent radiogenic progeny within natural gas handling, treatment, and distribution facilities. Worker safety issues and disposal challenges arise when these accumulate to radiologically problematic activity levels. This is due to the 22.3-year half-life of Lead-210, allowing for multi-decade period of accumulation to occur and to persist, even after facility operations have ceased. Due to the far shorter half-lives of Lead-210 radiogenic progeny, especially that of Polonium-210, secular equilibrium within the Lead-210-Bismuth-210-Polonium-210 decay chain is quickly approached during facility operations and achieved after facility operations end. Lead-210 that accumulates in pipe scale can complicate any subsequent intrusive facility modifications, such as disassembly and dismantlement, potentially exposing workers to adverse radioactivity and impeding recycling and/or disposal of radiologically impacted equipment or other material. Experience has shown it is not strictly the presence of Lead-210 that is problematic but rather its 'unexpected' presence when this Technologically Enhanced Naturally Occurring Radioactive Material (TENORM) is discovered during intrusive work not incorporating radiological health and safety and material handling plans. Conversely, when implementing a program that proactively considers the potential for Lead-210, this form of TENORM simply becomes another 'special waste' that can be safely, efficiently, and effectively addressed during a decommissioning effort, without associated adverse worker exposures, project cost over-runs, and schedule delays. This paper will discuss how proactive radioactive scanning quickly and safely identified Lead-210 and its radiogenic progeny within a natural gas sweetening and compressor station located in northern Montana, a portion of which was undergoing decommissioning, aiding in safe and compliant material handling and recycling. The location of this operation necessitated that the decommissioning program be completed on schedule to prevent weather-related impacts due to the onset of adverse winter conditions. Further, the radioactive data acquired during this project will be shown to provide important insight into historic behavior of Lead-210 in terms of its disposition and its more recent decay. From these data, it became possible to back-model the average activity of Radon-222 within the natural gas being processed during the life of the operation, how the estimated Radon-222 activity within the processed natural gas conformed to measured Radon-222 at various other natural gas fields, and how this information can be leveraged in developing safe and successful plans for future intrusive work at this and companion site operations. This presentation will also note the apparent preferential accumulation of Lead-210 within both rubber-based materials, such as gaskets and seals, and grease-based products found within natural gas flow lines. Thoughts regarding processes that may lead to this finding will be explored. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2019

Graphene: a Barrier to Hydrogen Permeation

Small area freestanding monolayer graphene has been shown to be impermeable to standard gases including hydrogen and helium.1 Several recent reports have suggested that graphene can be used as a hydrogen permeation barrier on metals.2 Those studies have relied on electrochemical hydrogen permeation measurements, which do a good job reproducing bulk permeability compared to gaseous diffusion but do not always reflect the real surface effects due to the difference in driving forces. This problem is magnified when measuring the permeability of thin coatings, which are dominated by surface effects. For this reason, we performed gas driven hydrogen permeation measurements of graphene coated metal samples. The diffusion of hydrogen through a metal can be described using Fick's and Sievert's Laws. Graphene-coated copper foils were prepared using chemical vapor deposition (CVD) with a methane precursor. Photo-reduced graphene samples were prepared by first sputtering a layer (∼15 nm) of copper on top of stainless steel foils. Graphene oxide in ethanol solutions were then drop cast on the surface and photo reduced using a neon lamp. A custom-designed apparatus has been assembled for measuring the hydrogen permeability of various materials. The operating principle of the system is as follows: A sample is sealed between the fore-sample and post-sample chambers using standard vacuum gaskets. Hydrogen is introduced into the fore sample region at varying pressures while the post sample region is maintained under high vacuum. Due to the concentration gradient, hydrogen then diffuses through the material and is detected using a quadrupole mass spectrometer. This process is repeated at several temperatures. The mass spectrometer was calibrated using an orifice with known conductance in place of the sample. Data collection and reduction were automated using scripts written in LabVIEW and Octave, respectively. We saw a decrease in the hydrogen permeability of copper after adding graphene to the surface for small temperature steps. This result is also observed when considering temperature steps of 20 K. Future Work: Apply this methodology to graphene-coated 316L stainless steel. The hydrogen permeability of 316L steel should also decrease with the addition of graphene to the surface. Determine methods for graphene defect reduction.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

DOE OSTI2016

Miniature High Temperature Testing Unit for HEPA Filter Materials R and D

The objective of this research is to develop and deploy advances in High Efficiency Particulate Air (HEPA) filter technology to benefit nuclear facilities. There is a need for better HEPA filter materials, especially those able to withstand moisture and higher temperatures as experienced in fire conditions. In order to test these materials, student teams at California Polytechnic State University (Cal Poly) have developed tools with the sponsorship and direction of Lawrence Livermore National Laboratory (LLNL). The Miniature High Temperature Testing Unit (MiniHTTU) can rapidly, efficiently and inexpensively test a large number of new and innovative materials for HEPA filter components. MiniHTTU test results will be used to down select the most promising materials for HEPA filter components (e.g., media, sealants, gaskets) for full scale testing in the full size High Temperature Testing Unit (HTTU). Using both testing units, future teams will be able to develop advances in HEPA filter technology (e.g., related to ceramic HEPA filters), the deployment of which will 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. (authors)

36 MATERIALS SCIENCE↗

DOE OSTI2024

Destructive Examination Protocol for 3013-Container-Package Storing Plutonium-Bearing Materials

The 3013-container-package consists of a convenience, inner and outer container and is used for long-term storage of plutonium-bearing materials. A destructive examination (DE) protocol has been developed to examine the container package visually and with microscopic aid to find any corrosion conditions that could result in the loss of the integrity of the container package over its lifetime. The DE protocol contains three main steps: initial container examination, helium (He) leak testing, and detailed imaging and analysis of the inner container closure weld region (ICCWR). The ICCWR has been determined to be bounding, defined as exhibiting worst case conditions for stress corrosion cracking (SCC) of the inner container. To assess SCC in the ICCWR, the inner container lid is cut into quarters and the weld and He-leak testing gasket are removed. Then a citric acid wash is performed to remove adherent chlorides from the ICCWR. The wash is then sent for analysis to determine the concentration of chlorides in the ICCWR. While the analysis for chloride concentration is being performed, the quarter sections are further sectioned into 1/8th subsections by cutting each section in half. These subsections are washed using nitric acid to remove corrosion products. Then each subsection is imaged using a Wide Angle 3-D Measurement System (WAMS). After analysis of microscope images for potential SCC, additional imaging can be performed, including subsurface imaging. After review, a determination is made of whether the container integrity may potentially affect the safe storage of the material.

container↗

DOE OSTI2014

PCTFE as a solution to birefringence in atom trap viewports

We have developed and characterized optical viewports with the glass-to-metal seal made by the plastic PCTFE (polychlorotrifluoroethylene). The goal is to reduce stress-induced birefringence while maintaining ultra-high vacuum compatibility. We have maintained a Stokes parameter S{sub 3} of 0.9986, and achieved <5 × 10{sup −11} Torr partial pressure of air. We have also measured the diffusion and permeation of helium through PCTFE and placed upper limits on nitrogen, oxygen, and argon permeation, as PCTFE has been suggested as an o-ring for transport of environmental noble gas samples, though we know of no other noble gas measurements.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2015

Note: O-ring stack system for electron gun alignment

We present a reliable method for aligning an electron gun which consists of an electron source and lenses by controlling a stack of rubber O-rings in a vacuum condition. The beam direction angle is precisely tilted along two axes by adjusting the height difference of a stack of O-rings. In addition, the source position is shifted in each of three orthogonal directions. We show that the tilting angle and linear shift along the x and y axes as obtained from ten stacked O-rings are ±2.55° and ±2 mm, respectively. This study can easily be adapted to charged particle gun alignment and adjustments of the flange position in a vacuum, ensuring that its results can be useful with regard to electrical insulation between flanges with slight modifications.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2023

Comparison of Multi-Scale Nonlinear and Conventional Linear Methods for Stress Analysis of Nb 3 Sn Superconducting Magnets

Here this is an extension of the work on a multi-scale nonlinear procedure that demonstrated how to conduct nonlinear stress analysis of Nb 3 Sn superconducting accelerator magnets. The nonlinear procedure uses measured stress-strain curves of annealed copper, Nb 3 Sn strands and coil samples as inputs, which reduces the number of assumptions made for material properties—key uncertainties of any engineering analysis. The results from nonlinear analysis, semi-nonlinear analysis, and linear analysis of the same QFFB2 Nb 3 Sn quadrupole magnet under the same temperature and loads, were compared and discussed. The comparison illustrates that nonlinear stress analysis is significantly more accurate than other methods. As the superconducting coil block is a complex, composite material, it would be inadequate to assume the whole coil block to be linear, either isotropic or orthotropic. It is imperative to conduct nonlinear analysis by simulating the superconducting coil to the level of detail of the individual cables and individual strands. The nonlinear stress analysis procedure can be used to simulate not only Nb 3 Sn magnets, but also NbTi and HTS magnets.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2012

Fluorine contamination in yttrium-doped barium zirconate film deposited by atomic layer deposition

The authors have investigated the change of chemical composition, crystallinity, and ionic conductivity in fluorine contaminated yttrium-doped barium zirconate (BYZ) fabricated by atomic layer deposition (ALD). It has been identified that fluorine contamination can significantly affect the conductivity of the ALD BYZ. The authors have also successfully established the relationship between process temperature and contamination and the source of fluorine contamination, which was the perfluoroelastomer O-ring used for vacuum sealing. The total removal of fluorine contamination was achieved by using all-metal sealed chamber instead of O-ring seals.

36 MATERIALS SCIENCE↗

DOE OSTI2012

Review of Aging Data on EPDM O-Rings in the H1616 Shipping Package

Currently, all H1616 shipping package containers undergo annual re-verification testing, including containment vessel leak testing to verify leak-tightness (<1 x 10 -7 ref cc/sec air) as per ANSI N14.5. The purpose of this literature review is to supplement aging studies currently being performed by SRNL on the EPDM O-rings to provide the technical basis for extending annual re-verification testing for the H1616 shipping package and to predict the life of the seals at bounding service conditions. The available data suggest that the EPDM O-rings can retain significant mechanical properties and sealing force at or below bounding service temperatures (169 °F or 76 °C) beyond the 1 year maintenance period. Interpretation of available data suggests that a service life of at least 2 years and potentially 4-6 years may be possible at bounding temperatures. Seal lifetimes at lower, more realistic temperatures will likely be longer. Being a hydrocarbon elastomer, EPDM O-rings may exhibit an inhibition period due to the presence of antioxidants. Once antioxidants are consumed, mechanical properties and seal performance could decline at a faster rate. Testing is being performed to validate the assumptions outlined in this report and to assess the long-term performance of O-ring seals under actual service conditions.

42 ENGINEERING↗

DOE OSTI2012

Compatibility Study for Plastic, Elastomeric, and Metallic Fueling Infrastructure Materials Exposed to Aggressive Formulations of Ethanol-blended Gasoline

In 2008 Oak Ridge National Laboratory began a series of experiments to evaluate the compatibility of fueling infrastructure materials with intermediate levels of ethanol-blended gasoline. Initially, the focus was elastomers, metals, and sealants, and the test fuels were Fuel C, CE10a, CE17a and CE25a. The results of these studies were published in 2010. Follow-on studies were performed with an emphasis on plastic (thermoplastic and thermoset) materials used in underground storage and dispenser systems. These materials were exposed to test fuels of Fuel C and CE25a. Upon completion of this effort, it was felt that additional compatibility data with higher ethanol blends was needed and another round of experimentation was performed on elastomers, metals, and plastics with CE50a and CE85a test fuels. Compatibility of polymers typically relates to the solubility of the solid polymer with a solvent. It can also mean susceptibility to chemical attack, but the polymers and test fuels evaluated in this study are not considered to be chemically reactive with each other. Solubility in polymers is typically assessed by measuring the volume swell of the polymer exposed to the solvent of interest. Elastomers are a class of polymers that are predominantly used as seals, and most o-ring and seal manufacturers provide compatibility tables of their products with various solvents including ethanol, toluene, and isooctane, which are components of aggressive oxygenated gasoline as described by the Society of Automotive Engineers (SAE) J1681. These tables include a ranking based on the level of volume swell in the elastomer associated with exposure to a particular solvent. Swell is usually accompanied by a decrease in hardness (softening) that also affects performance. For seal applications, shrinkage of the elastomer upon drying is also a critical parameter since a contraction of volume can conceivably enable leakage to occur. Shrinkage is also indicative of the removal of one or more components of the elastomers (by the solvent). This extraction of additives can negatively change the properties of the elastomer, leading to reduced performance and durability. For a seal application, some level of volume swell is acceptable, since the expansion will serve to maintain a seal. However, the acceptable level of swell is dependent on the particular application of the elastomer product. It is known that excessive swell can lead to unacceptable extrusion of the elastomer beyond the sealed interface, where it becomes susceptible to damage. Also, since high swell is indicative of high solubility, there is a heightened potential for fluid to seep through the seal and into the environment. Plastics, on the other hand, are used primarily in structural applications, such as solid components, including piping and fluid containment. Volume change, especially in a rigid system, will create internal stresses that may negatively affect performance. In order to better understand and predict the compatibility for a given polymer type and fuel composition, an analysis based on Hansen solubility theory was performed for each plastic and elastomer material. From this study, the solubility distance was calculated for each polymer material and test fuel combination. Using the calculated solubility distance, the ethanol concentration associated with peak swell and overall extent of swell can be predicted for each polymer. The bulk of the material discussion centers on the plastic materials, and their compatibility with Fuel C, CE25a, CE50a, and CE85a. The next section of this paper focuses on the elastomer compatibility with the higher ethanol concentrations with comparison to results obtained previously for the lower ethanol levels. The elastomers were identical to those used in the earlier study. Hansen solubility theory is also applied to the elastomers to provide added interpretation of the results. The final section summarizes the performance of the metal coupons.

02 PETROLEUM↗

DOE OSTI2012

Status report for aging studies of epdm o-ring material for the h1616 shipping package

This is an interim status report for tasks carried out per Task Technical Plan SRNL-STI-2011-00506. A series of tasks/experiments are being performed at the Savannah River National Laboratory to monitor the aging performance of ethylene propylene diene monomer (EPDM) Orings used in the H1616 shipping package. The data will support the technical basis to extend the annual maintenance of the EPDM O-rings in the H1616 shipping package and to predict the life of the seals at bounding service conditions.

99 GENERAL AND MISCELLANEOUS↗

DOE OSTI2015

Aging Study Of EPDM O-Ring Material For The H1616 Shipping Package - Three Year Status

This is a 3-year status report for tasks carried out per Task Technical Plan SRNL-STI-2011-00506. A series of tasks/experiments were performed at the Savannah River National Laboratory (SRNL) to monitor the aging performance of ethylene propylene diene monomer (EPDM) O-rings used in the H1616 shipping package. The test data provide a technical basis to extend the annual maintenance of the H1616 shipping package to three years and to predict the life of the EPDM O-rings at the bounding service conditions.

42 ENGINEERING↗

DOE OSTI2015

The 9975 Type B shipping package is used within the DOE complex for shipping special nuclear materials. This package is re-certified annually in accordance with Safety Analysis Report for Packaging (SARP) requirements. The package is also used at the Savannah River Site as part of the long-term storage configuration of special nuclear materials. As such, the packages do not undergo annual recertification during storage, with uncertainty as to how long some of the package components will meet their functional requirements in the storage environment. The packages are currently approved for up to 15 years storage, and work continues to provide a technical basis to extend that period. This report describes efforts by the Savannah River National Laboratory (SRNL) to extend the service life estimate of Viton® GLT and GLT-S fluoroelastomer O-rings used in the 9975 shipping package. O-rings of both GLT and GLT-S compositions are undergoing accelerated aging at elevated temperature, and are periodically tested for compression stress relaxation (CSR) behavior. The CSR behavior of O-rings was evaluated at temperatures from 175 to 400 °F. These collective data were used to develop predictive models for extrapolation of CSR behavior to relevant service temperatures (< 156 °F). The predictive model developed from the CSR data conservatively indicates a service life of approximately 37 years for Viton GLT O-rings at the maximum effective service temperature of 156 °F. The estimated service life for Viton GLT-S O-rings is significantly longer.

36 MATERIALS SCIENCE↗

DOE OSTI2016

Eleventh interim status report: Model 9975 O-Ring fixture long-term leak performance

A series of experiments to monitor the aging performance of Viton® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. One approach has been to periodically evaluate the leak performance of O-rings being aged in mock-up 9975 Primary Containment Vessels (PCVs) at elevated temperature. Other methods such as compression-stress relaxation (CSR) tests and field surveillance are also on-going to evaluate O-ring behavior. Seventy tests using PCV mock-ups were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they continue to meet the leak-tightness criterion defined in ANSI standard N14.5-97. Due to material substitution, fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF.

42 ENGINEERING↗