bluuebunny/crossref_metadata_2025 huggingface dataset:
Maintenance of Low Pressure Septic Tank Effluent Distribution Systems
Authors: Gross MA , Rutledge EM , Wolf DC , Bomblat C
Published: March 2009

Low pressure distribution systems (LPD) are used to provide even distribution of septic tank effluent (STE) in septic system filter fields. LPD systems have been used to prevent surfacing of STE due to clogging of one area of the soil due to overloading, or to provide even distribution in high hydraulic conductivity soils for better treatment of the STE as it infiltrates through the soil. Even distribution of the STE is provided by pumping to pressurize small-diameter holes in the lateral pipe of the soil absorption trenches. The hole diameter is 3.2 mm and the pressure at the small orifi is typically designed for 1.5 m of water head (14.7 kPa). Concern has been expressed regarding clogging of the small-diameter holes. Instrumentation and data logging equipment were installed to measure and record the number and length of pump cycles for two separate and LPD lateral lines. The study has been ongoing since June, 1991, and the pump cycle times have been checked every two weeks. When the pump cycle times appeared excessive, the pressurized distribution pipes were opened and cleaned using a simple drain cleaning device. The cleaning procedure required approximately 30 minutes for two 12 m LPD laterals. Following the cleaning, pump cycle times were reduced. The cleaning was performed at intervals ranging from 35 to 66 weeks. The results of this field study show that a simple pump cycle timer and counter will provide information for maintenance of the pressurized laterals, and that approximately once per year, the laterals may need cleaning.
SITE EVALUATION PROCEDURES FOR INDIVIDUAL SEWAGE TREATMENT SYSTEMS IN DISTURBED SOILS
Authors: Wespetal MS , Schirmers SB
Published: March 2009

Soil pedogenic processes produce an aggregation of soil particles which results in the development of soil structure. In turn, the development of soil structure increases the porosity and interconnection of soil pores. This process has a positive affect on the rate of fluid movement. When soils are moved, manipulated or compacted, the soil structure is damaged or destroyed or particles rearranged, which for many soil textures and flow regimes, reduces the soil's ability to transmit fluids.

Codes which govern the design of individual sewage treatment systems were developed under the assumption that systems were to be placed in natural soils. Therefore, if a proposed system is to be designed for an area of disturbed soils, the methods described in the code may not directly apply. This may result in premature hydraulic failure of the system. The application of Minnesota's ISTS code in disturbed soils has resulted in failures at a frequency of concern to the state regulatory agency. Revisions to Minnesota's code classifies systems placed in or on disturbed soils as being experimental. The classification is meant to identify these systems as having an unknown degree of reliability and to provide a data gathering process at the state level to monitor the performance of various designs to overcome disturbance.

This paper describes the problems associated with disturbed soils, the methods of proper field identification, how to quantify the extent of disturbance and briefly discusses some mitigative measures in an attempt to overcome these limitations.
Minimizing On-Site Septic System Drain Field Size by Combining Absorbic and Evaporative Disposal Methods
Authors: Hart SW
Published: March 2009

There are two well established methods for the disposal of septic tank effluent in soil. The most common method utilizes the natural absorbic capacity of soil to move the effluent, over time, into groundwater. The other method is utilized in geographical areas of low to moderate rainfall and is based on effluent removal through surface evaporation with some contribution from plant transpiration. It is possible to reduce the size of a septic tank drain field, for a given effluent flow rate, by combining the two disposal methods. The amount of reduction is proportional to the absorbic capacity of the soil and net surface evaporation rate for a given geographical area.
Used Tires as a Substitute for Drainfield Aggregate
Authors: Burnell BN , McOmber G
Published: March 2009

This study summarizes the state of Idaho's approach to determine the suitability of reusing used tires for drainfield aggregate (drainrock) in standard subsurface sewage disposal systems and as a substitute for gravelless domed chamber systems. The used tire industry has developed alternative uses for used tires such as: a fuel supplement in incinerators, playground equipment, road building materials, marina boat dock bumpers, and for alternative daily cover at municipal solid waste landfills. Used tires are prohibited in Idaho from being disposed of in municipal solid waste landfills. The need exists to find several methods to reuse used tires because of the prohibition of landfilling tires and as an alternative to other more expensive methods of used tire disposal.

Researchers report that shredded tires do not release any significant amounts of priority pollutants. These reports provide a general indication that the use of used tires as road bed materials does not pose a risk to ground water. The use of chipped tires and half tires in drainfields has not been evaluated as to the potential for ground water contamination. This study addresses the information gap for use of waste tires in subsurface sewage disposal applications. Used tire chips as a substitute for drainrock release sulfer and zinc from the rubber, and iron from the reinforcing wire. This release of metals was not observed for the half tires placed in the gravelless domed chamber design.
Renovation of Septic Effluent in a Stratified Sand Filter
Authors: Nichols DJ , Wolf DC , Gross MA , Rutledge EM
Published: March 2009

Where soils are unsuitable for traditional filter fields, a sand filter may be used to renovate septic effluent. The objective of this study was to evaluate the renovation of chemical and biological components of septic tank effluent in a newly constructed stratified sand filter. The sand filter consisted of three layers of sand that decreased in coarseness with depth. The sand filter inflow NH4-N levels increased for 25 d with a mean level of 43 mg/L during the 864-d study. The outflow NO3-N con-centrations stabilized at 32 mg/L from 25 to 510 d. Inflow P reached a steady-state concentration of 16 mg/L while outflow P was <0.2 mg/L until 25 d. Thereafter, P outflow concentrations increased and had a mean value of 10 mg/L. Fecal coliform removal averaged 99.97% during the first 51 d. The stratified sand filter may provide an alternative wastewater disposal system for many locations.
Sewage and Leachate Wastewater Treatment Using Theabsorbent Waterloo Biofilter
Authors: Jowett EC
Published: March 2009

The Waterloo Biofilter™ is a new type of free-draining aerobic biofilter developed at the University of Waterloo to treat domestic septic tank effluent, but it is also effective for municipal sewage, landfill leachate, and other wastewaters. The optimized physical properties of the light-weight, plastic foam medium enable design loading rates of 50 cm/d, or ∼10 times that of soil leach fields and sand filters. The medium combines high retention time with high surface area for microbial attachment and allows simultaneous loading and aeration. Separate flow paths for air and water allow concurrent aerobic and anaerobic reactions, and minimal solids production. Maintenance is similar to a sand filter but more readily cleaned if needed. Typical mature field removal rates in a single pass are: Municipal Primary Clarifier:>95% BOD and TSS, >99.5% for total and fecal coliforms, and ∼80% ammonium at 50 cm/d; Municipal Secondary Clarifier or Lagoon: >90% BOD and TSS, >95% ammonium at 250 cm/d; Proteus METS System: 80–85% BOD and 75% TSS at 500 cm/d; Septic Tank Effluent: 90–95% BOD/TSS, 95–99% for coliforms, and 50–95% ammonium at 50 cm/d; andLandfill Leachate: 80–95% BOD, 95% ammonium, 98% hydrocarbons and VOCs and 50–95% heavy metals at 30 cm/d. Typical total nitrogen removal is 20–50% for sewage and depends on degree of nitrification. Preliminary virus work indicates efficient removal.
Evaluation of the Oxidation Behavior of Polyethylene Geomembranes Using Oxidative Induction Time Tests
Authors: Hsuan YG , Guan Z
Published: March 2009

The oxidation of five different high density polyethylene (HDPE) geomembranes was produced in a forced air oven at a temperature of 115°C. The antioxidant packages of three of the geomembranes contained hindered phenols and phosphites types of antioxidants. The antioxidant packages of the other two geomembranes consisted of either thiosynergists or hindered amines together with hindered phenols and phosphites. The consumption of antioxidants after given time periods of oven incubation was monitored by two oxidative induction time (OIT) tests: standard OIT and high pressure OIT together with tensile tests. The results indicated that both OIT tests can effectively track the consumption of hindered phenol and phosphite types of antioxidants. However, for thiosynergists and hindered amines, the high pressure OIT is the appropriate test. The study clearly demonstrated that mechanical properties do not decrease until all (or most) of the OIT value has been depleted. Thus, the reduction of OIT values is the precursor of material degradation.
Estimation of Bias in the Oxidative Induction Time Measurement by Pressure DSC
Authors: Marcus SM , Blaine RL
Published: March 2009

Oxidative induction time (OIT) is defined as the time to the onset of oxidation of a test specimen exposed to oxygen at an elevated isothermal test temperature. In the pressure differential scanning calorimetry embodiment of this test, the test specimen is often exposed to the oxidizing atmosphere as the apparatus is heated from ambient to the isothermal test temperature. This creates a bias in the measurement due to undetected oxidation on heating. An expression, based upon the Arrhenius equation, is derived and then numerically integrated to obtain an estimate of the bias introduced into the OIT measurement. The bias is dependent on the activation energy of the reaction and on the heating rate. It is found to be less than 1.2 minute for the most common heating rates, and is less than 3 minutes for the most extreme sets of experimental conditions. The bias is small when compared to experimental repeatability of the OIT measurement and to the mean of OIT values. For this reason, it may be ignored in all but the most extreme cases of low activation energy, very slow heating rates, very low OIT values and high test temperatures.
Development of Emulsifiable Concentrate Formulations Using Experimental Design Software
Authors: Butler BJ
Published: March 2009

This paper examines two experimentation processes for developing an emulsifier system for an EC herbicide formulation. The first process is the traditional method of single factor experimentation, and the second process uses DOE (Design of Experiments) computer software. A four component emulsifier system is optimized using both processes. The advantages and disadvantages of both processes are discussed.

The use of DOE techniques for mixtures gives the researcher a greater level of understanding of the interactions of the variables in the experimental system, compared to single factor experimentation. The software used in this study did create predictive models for the formulation developed, thus allowing the selection of the optimum blend of the components after evaluation of seventeen blends. The property selected for evaluation was emulsion separation as a function of water hardness.
Water in Oil Microemulsion Aerosol Systems for Insecticidal Compositions
Authors: Narayanan KS , Kaminsky M , Jon D , Ianniello RM
Published: March 2009

Conventional aerosol as a delivery system for hydrophobic insecticides, formulated with hydrocarbon or freon type propellants [(A46) or Freon 11/12] are derived from matrices based on non-aqueous organic solvents, i.e., either hydrocarbons or halogenated hydrocarbons. Such systems pose potential environmental hazards like high flammability (hydrocarbon emission) and depletion of the ozone layer from fluorinated hydrocarbons, and emission of chlorinated hydrocarbons as cancer suspect agents. Totally aqueous systems are not easy to formulate in a single phase system as are aerosols. While O/W microemulsions are described in the literature, their use as trigger spray or aerosol systems produced low knockdown rates (speed of ‘kill’). A W/O microemulsion which will accommodate high levels (⩾ 35%) of conventional hydrocarbon propellant (A46) would be safer and will improve the knockdown rate.

This paper describes our effort in successfully formulating such W/O microemulsion systems. A systematic approach to stabilize W/O microemulsions that can accommodate high level of water (25–40%) as well as high level of hydrocarbon oil and hydrocarbon propellant (40–50%) based on partial phase diagrams produced several prototype formulations. These formulations matrices essentially consist of: nonylphenol ethoxylates as primary emulsifiers and long chain (C8) alkyl pyrrolidone/pentanol/ glycerol as cosurfactant/cosolvents, C12 hydrocarbon and water. Mixed pyrethroids and propellants can be loaded at appropriate levels.

Examples of prototype formulations, stability data, and biological efficacy are provided. A working model that would explain the high biological performance is also provided.
Liquid Formulations of Non-Spore Forming Microorganisms
Authors: Wacek TJ
Published: March 2009

Biological formulations have evolved from the use of organic based solids such as peat as a preservative and delivery system to water based carriers. Water based formulations provide more convenience for the end user. Innovations in media preparation, stabilizing agents and packaging have led to stable formulations of non-spore forming microorganisms.

Liquid media for biological formulations contain either minimal nutrient levels packaged in air impermeable containers, or very high nutrient levels packaged in oxygen permeable plastic. Soluble polysaccharides (particularly alginates) can be used as stabilizing agents. Also, concentrated pastes of cells which are kept frozen until use, lyophilized powders, and oil suspensions are available. Two important points for the successful liquid formulation of a biological are long term stability (1 to 2 years) and effectivity at the site of use.
Why Organosilicone Adjuvants Spread
Authors: Hill RM , Burow RF
Published: March 2009

The use of certain organosilicone surfactants as agricultural adjuvants has come about as a result of their unusual ability to promote the rapid spreading of dilute solutions on hydrophobic leaf surfaces. The reason for this unique spreading is not well understood.

The spreading of surfactant solutions, including the organosilicone surfactants, has recently been shown to exhibit a maximum in spreading rate as the surfactant concentration is increased, and as the substrate is made more hydrophobic. Certain organic surfactants promote spreading equally as rapid as the organosilicones on slightly less hydrophobic surfaces. Organosilicone surfactants, on the other hand, exhibit rapid spreading even on very hydrophobic surfaces. Some have attributed the rapid spreading of the organosilicone surfactants to their unique molecular shape, but the evidence does not support this. A correlation has been found between solubility or turbidity and spreading-those materials which form turbid dispersions seem to provide the most rapid spreading. In this case turbidity is due to the presence of a dispersion of bilayer vesicles. The presence of vesicles contributes to the low dynamic surface and interfacial tensions at short time scales, leading to the ability to spread more rapidly over more hydrophobic substrates.
Solid Adjuvant Systems — Formulations, Stability, and Efficacy
Authors: Narayanan KS , Talion M
Published: March 2009

Adjuvants are increasingly used as a means of reducing pesticides in the environment by providing biological enhancement. Incorporation of adjuvants with the active ingredients can produce added value and product differentiation. Examples of solid forms of adjuvants that can provide multiple benefits are not very common. Solid adjuvants have several advantages like elimination of containers (using water dispersible/soluble bags), capability of direct incorporation with solid formulations (wettable powders, water soluble/dispersible granules), and use as tank mix additives.

Formulated value added multibenefit adjuvant systems (Agrimax 3 ™) are described in the literature [Narayanan, 1993]. These are optimized microemulsions containing alkyl pyrrolidones, anionic surfactants and water insoluble copolymers derived from vinyl pyrrolidones. Agrimax systems are designed to provide increased spreading, penetration and rainfastness. A second type of adjuvants is copolymers of vinyl pyrrolidones containing positive pendant groups (Restrict ™). Restrict ™ polymers are shown to reduce leaching of pesticides from the soil [Narayanan, et. al., 1993 a].

The above adjuvant systems were converted to value added solid forms by the use of specific complexing agents like urea. Prototype compositionsderived from the above adjuvant systems, preparative methods, stability, physical properties, and biological performance are discussed. The role of urea as a complexing agent is also discussed.
Lipophilic Chemistry Affects Surfactant Phytotoxicity and Enhancement of Herbicide Efficacy
Authors: Manthey FA , Szelezniak EF , Nalewaja JD
Published: March 2009

Nonionic surfactants are comprised of a lipophilic and a hydrophilic moiety. Experiments were conducted to determine the effect of the lipophilic moiety on droplet spread; surfactant phytotoxicity, and surfactant enhancement of herbicide phytotoxicity. Six different lipophilic moieties and two herbicides were evaluated on four plant species. Each lipophilic moiety was represented by two surfactants: one with a low hydrophilic:lipophilic balance (HLB) value, near 12.0, and one with a high HLB value, near 16.0. Droplet spread was greater with low than high HLB surfactants and was greatest with trimethylnonanol ethoxylate (TMN); intermediate with secondary alcohol ethoxylate (SAE) and octylphenol ethoxylate (OPE), and least with linear alcohol ethoxylate (LAE), nonylphenol ethoxylate (NPE), and oxysorbic (TWN). Surfactant enhancement of droplet spread was less on redroot pigweed (Amaranthus retroflexus) than on barley (Hordeum vulgare), green foxtail (Setaria viridis), or kochia (Kochia scoparia). Isopropylamine salt of glyphosate [N- (phosphonomethyl)glycine] and the ammonium salt of imazethapyr {2-[4,5-dihydro-4-methyl-4-(1-methylethyl-5-oxo-1H-imidazol-2-yl] -5-ethyl-3-pyridinecarboxylic acid} had little effect on droplet spread. Lipophilic chemistry and HLB affected surfactant phytotoxicity to green foxtail, kochia, and redroot pigweed but not to barley. Foliar injury ranged from 1 to 23% with green foxtail, 0 to 17% with kochia, and 0 to 14% with redroot pigweed. Injury to barley was similar for all surfactants and ranged from 3 to 8%. Injury generally was greater with low than high HLB surfactants. However, SAE and OPE caused greater injury to green foxtail at high than low HLB. Green foxtail was the only plant species injured more than 8% by high HLB surfactants. Droplet spread did not correlate with surfactant phytotoxicity regardless of plant species. Glyphosate phytotoxicity generally was enhanced most by high HLB LAE to barley, green foxtail, and kochia and by high HLB TWN to redroot pigweed. Imazethapyr phytotoxicity was generally greatest when applied with high HLB SAE to barley and redroot pigweed, with high HLB LAE to green foxtail and with low HLB LAE to kochia. Neither droplet spread nor surfactant phytotoxicity correlated with glyphosate or imazethapyr efficacy.
The Impact of Mobile Point Defect Clusters in a Kinetic Model of Pressure Vessel Embrittlement
Authors: Stoller RE
Published: March 2009

The results of recent molecular dynamics simulations of displacement cascades in iron indicate that small interstitial clusters may have a very low activation energy for migration, and that their migration is 1-dimensional, rather than 3-dimensional. The mobility of these clusters can have a significant impact on the predictions of radiation damage models, particularly at the relatively low temperatures typical of commercial, light water reactor pressure vessels (RPV) and other out-of-core components. A previously-developed kinetic model used to investigate RPV embrittlement has been modified to permit an evaluation of the mobile interstitial clusters. Sink strengths appropriate to both 1- and 3-dimensional motion of the clusters were evaluated. High cluster mobility leads to a reduction in the amount of predicted embrittlement due to interstitial clusters since they are lost to sinks rather than building up in the microstructure. The sensitivity of the predictions to displacement rate also increases. The magnitude of this effect is somewhat reduced if the migration is 1-dimensional since the corresponding sink strengths are lower than those for 3-dimensional diffusion. The cluster mobility can also affect the evolution of copper-rich precipitates in the model since the radiation enhanced diffusion coefficient increases due to the lower interstitial cluster sink strength. The overall impact of the modifications to the model is discussed in terms of the major irradiation variables and material parameter uncertainties.
Use of Forces from Instrumented Charpy V-Notch Testing to Determine Crack-Arrest Toughness
Authors: Iskander SK , Nanstad RK , Sokolov MA , McCabe DE , Hutton JT , Thomas DL
Published: March 2009

The objective of this investigation is an estimation of the crack-arrest toughness, particularly of irradiated materials, from voltage versus time output of an instrumented tup during a test on a Charpy V-notch (CVN) specimen. This voltage versus time trace (which can be converted to force versus displacement) displays events during fracture of the specimen. Various stages of the fracture process can be identified on the trace, including an arrest point indicating arrest of brittle fracture. The force at arrest, Fa, versus test temperature, T, relationship is examined to explore possible relationships to other experimental measures of crack-arrest toughness such as the drop-weight nil-ductility temperature (NDT), or crack-arrest toughness, Ka. For a wide range of weld and plate materials, the temperature at which Fa = 2.45 kN correlates with NDT with a standard deviation, σ, of about 11 K. Excluding the so-called “low upper-shelf energy” (USE) welds from the analysis resulted in Fa = 4.12 kN and σ = 6.6 K. The estimates of the correlation of the temperature for Fa = 7.4 kN with the temperature at 100-MPa·√m level for a mean American Society of Mechanical Engineers (ASME) type KIa curve through crack-arrest toughness values show that prediction of conservative values of Ka are possible.
Auger Spectroscopy of Magnox Pressure Vessel Steels
Authors: Fisher S , Knowles G , Lee B
Published: March 2009

Magnox Electric maintains a significant microstructural programme in support of its safety case for operation of its stations with steel pressure vessels. An important part of this programme is the characterisation of grain boundary chemistry using Auger spectroscopy. Mechanical testing and subsequent examination of surveillance material has shown that some Charpy specimens display a proportion of intergranular fracture and Auger work has linked this to the presence of phosphorus on the grain boundaries. A feature of particular interest in the study of the boundaries is the co-segregation of carbon. The measurement of the ‘true’ levels of phosphorus and carbon segregation is complicated by the presence of carbon contamination. This paper describes the simple approach used to overcome this problem.
SANS Study of High-Copper RPV Welds in Irradiated and Annealed Conditions
Authors: Sokolov MA , Spooner S , Odette GR , Wirth BD , Lucas GE
Published: March 2009

Small-angle neutron scattering (SANS) has been used to study reactor pressure vessel (RPV) welds from the Heavy-Section Steel Irradiation (HSSI) Program. Each of the welds contains high bulk copper contents ranging from 0.26 to 0.40 wt %. The welds were irradiated in test reactors to fluences ranging from 0.5 to 1.9 x 1019 n/cm2 (E > 1 MeV). SANS measurements were performed to determine number density, radius, and volume fraction of irradiation-induced scattering centers which were consistent with copper-rich precipitates (CRPs). The bulk copper content had no effect on CRP number density, volume fraction, and average radius. Postirradiation annealing (PIA) was performed on the welds for 168 h at 343, 399, and 454°C. SANS measurements on these samples show that high temperature PIA decreases the CRP number density and volume fraction while increasing the average radius. The SANS data obtained on these welds are consistent with the University of California, Santa Barbara, database and comparison is made with two A533B type model alloys irradiated to a similar fluence and following PIA. Evolution of the CRP scattering centers with irradiation and PIA is compared to the changes in mechanical properties.
Empirical Correlation of Observed Three Stages of Fast Neutron Irradiation Hardening and Embrittlement in WWER-440 Pressure Vessel Materials
Authors: Levit VI , Korolev YuN , Tipping Ph , Lessa RNT
Published: March 2009

Correlations between irradiation hardening and embrittlement of 10 different WWER-440 pressure vessel materials has been investigated. The presence of three stages of fast neutron irradiation hardening (RH) and embrittlement (RE) has been detected. Good empirical correlation between RH and RE was found in the first stage of the irradiation hardening stage. In the second stage, the RE process appears less intensive compared with the first one. In fact, there was only slight hardening and, in some cases, softening occurred; consequently, there was no correlation between RH and RE in the second stage. It is indicated that the RH and RE processes take place in or on different surfaces (grain bulk, grain boundaries and on precipitates) and therefore have local character. It is possible that the delay of RH and RE appearance is related to the nucleation and subsequent growth of precipitates.
Evaluation of Irradiated Pressure Vessel Steel by Mechanical Tests and Positron Annihilation Lineshape Analysis
Authors: Nakamura N , Ohta Y , Yoshida K , Maeda N
Published: March 2009

Mechanical test and positron annihilation lineshape analysis have been performed on neutron irradiated pressure vessel steels, A533B1 steel and the weld metal. Marked changes in the mechanical properties were observed for both metals after the neutron exposure. S-parameters, the positron annihilation parameters, also increased after the neutron irradiation but only the small change was observed in the different levels of neutron fluence. The change in S-parameter and the mechanical properties were well correlated. It is concluded that changes in embrittlement induced by radiation can be monitored by positron annihilation lineshape analysis but detectability is dependent on the materials.
Detection of Radiation Damage in Low Alloy Steel Using a Squid Sensor
Authors: Otaka M , Shimizu S , Morinaka R , Maeda N , Yamaguchi A
Published: March 2009

The magnetic properties of A533B low alloy steel irradiated up to 3 x 1023 n/m2 in a nuclear reactor were measured using a SQUID sensor. The SQUID sensor used in the test is the type with a first-order axial gradiometer. Test specimens were irradiated to 0.5 x 1023 and 3.0 x 1023 n/m2, and then magnetized in a 0.2 T field until saturation before measurement. The specimens were put on a scanning table in a hot laboratory and the SQUID output was recorded while each specimen was gradually moved in a horizontal direction under the SQUID sensor. A superconducting magnet was used to put the test specimen under a magnetic field that changed from +0.01 T to -0.01 T to observe the relation between magnetic field intensity and coercive force (B-H curve). The B-H curve shows a definite tendency towards a higher coercive force for test specimens with higher neutron fluence. The test result also shows a good relation between mechanical properties, such as yield strength, tensile strength, and the Charpy impact test result, with SQUID output. This proves that there is a very good chance of developing a non-destructive evaluation system for nuclear reactor structure. This kind of evaluation system would be a great help in making plant life management even more reliable and reasonable.
Tensile Properties of a Titanium Modified Austenitic Stainless Steel and the Held Joints after Neutron Irradiation
Authors: Shiba K , Ioka I , Jitsukawa S , Hamada S , Hishinuma A , Robertson JP
Published: March 2009

Tensile specimens of a titanium modified austenitic stainless steel and its weldments fabricated with Tungsten Inert Gas (TIG) and Electron Beam (EB) welding techniques were irradiated to a peak dose of 19 dpa and a peak helium level of 250 appm in the temperature range between 200 and 400° C in spectrally tailored capsules in the Oak Ridge Research Reactor (ORR) and the High Flux Isotope Reactor (HFIR). The He/dpa ratio of about 13 appm/dpa is similar to the typical helium/dpa ratio of a fusion reactor environment. The tensile tests were carried out at the irradiation temperature in vacuum. The irradiation caused an increase in yield stress to levels between 670 and 800 MPa depending on the irradiation temperature. Total elongation was reduced to less than 10%, however the specimens failed in a ductile manner. The results were compared with those of the specimens irradiated using irradiation capsules producing larger amount of He. Although the He/dpa ratio affected the microstructural change, the impact on the post irradiation tensile behavior was rather small not only for base metal specimens but also for the weld joint and the weld metal specimens.
Behavior of Fe-Cr-Ni-xP-yTi Alloys under Electron/He Ion Dual Beam Irradiation
Authors: Takahashi H , Tsuchida H , Hidaka Y , Kinoshita H , Watanabe S
Published: March 2009

The effect of helium on microstructural development during dual beam irradiation with electrons/ He+ ions was examined for Fe-16wt%Cr-14wt%Ni-xwt%P-ywt%Ti (x=0, 0.1, y=0, 0.1) model alloys. Irradiation was carried out using a high voltage electron microscope (1000kv) connecting with 300 keV ion accelerator. The simultaneous ion injection rate was 20 at.ppm He/ dpa at 70KeV and irradiation temperatures were 723 K and 773K. In the phosphorus containing alloy, vacancy type dislocation loops were nucleated in the early irradiation stage with electrons beam irradiation. Voids were nucleated from lower dose during electrons/ He+ ions dual beam irradiations. In the titanium contained alloy, under electrons/ He ions dual irradiation, void nucleation was lower comparing to phosphorus containing alloy under electron beam. Furthermore, structural development in alloy containing both titanium and phosphorous was similar to that of alloy with phosphorus and dislocation density was very high. From these results it was clarified that helium strongly influences void nucleation in each alloy as a result of interaction between phosphorus and interstitials
Irradiation Creep at Temperatures of 400°C and Below for Application to Near-Term Fusion Devices
Authors: Grossbeck ML , Gibson LT , Jitsukawa S , Mansur LK , Turner LJ
Published: March 2009

A series of six austenitic stainless steels and two ferritic alloys were irradiated sequentially in two research reactors where the neutron spectrum was tailored to produce a He transmutation rate typical of a fusion device. Irradiation began in the Oak Ridge Research Reactor. After an atomic displacement level of 7.4 dpa was achieved, the specimens were moved to the High Flux Isotope Reactor for the remainder of the 19 dpa accumulated. Irradiation temperatures of 60, 200, 330, and 400°C were studied with internally pressurized tubes of type 316 stainless steel, PCA, HT 9, and a series of four laboratory heats of: Fe-13.5Cr-15Ni, Fe-13.5Cr-35Ni, Fe-13.5Cr-15Ni- 0.18Ti, and Fe-16Cr. At 330°C, irradiation creep was shown to be linear with fluence and stress. There was little or no effect of cold-work on creep under these conditions at all temperatures investigated. The HT9 demonstrated a large deviation from linearity at high stress levels, and a minimum in irradiation creep with increasing stress was observed in the Fe-Cr-Ni ternary alloys.
Variability of Irradiation Creep and Swelling of HT9 Irradiated to High Neutron Fluence at 400–600°C
Authors: Toloczko MB , Garner FA
Published: March 2009

Sets of pressurized tubes constructed from a combination of three lots of HT9 and two heat-treatments were examined after irradiation in FFTF-MOTA at four different temperatures between 400 and 600°C. Diametral measurements indicated that small amounts of swelling occurred at 400°C, with the magnitude of the swelling varying from tube-set to tube-set. At 495, 550, and 600°C, no indications of swelling were observed. Over a limited stress range that decreased with increasing irradiation temperature, the irradiation creep was found to be proportional to the stress level and mirrored the swelling behavior, confirming the Bo + DS creep model. The creep compliance, Bo, appears to be about half of that observed in austenitic steels, whereas the creep-swelling coupling coefficient, D, appears to be comparable to that of austenitics. At the highest stress levels examined, the value of the stress exponent became much greater than 1.0. Higher irradiation temperatures resulted in creep behavior with pronounced thermal creep characteristics. A primary creep transient was observed at the three higher irradiation temperatures and increased in magnitude with increasing irradiation temperature, while a stress exponent between 1.0 and 2.0 was observed at 550°C.
Evaluation of Low-Temperature Swelling in Austenitic Stainless Steels
Authors: Katoh Y
Published: March 2009

Major portions of structural materials of near-term fusion blankets and light water reactor core components are subject to neutron irradiation at low temperatures and low fluxes compared to those in typical void swelling studies using fast reactors. Observed swelling in austenitic stainless steels at temperatures below 673K are generally very small under typical fast reactor irradiation conditions, however, the amount of swelling might be significantly influenced by neutron flux, helium generation rate, etc. In this work, using a reaction rate theory model of swelling, the influences of such key irradiation parameters on low temperature swelling behavior in austenitic stainless steels will be demonstrated to aid the evaluation of swelling at low temperature and low neutron flux conditions.
The Effects of Phase Stability on Void Swelling in P, Ti-Modified 316 Stainless Steels During Neutron Irradiation
Authors: Ukai S , Akasaka N , Hattori K , Onose S
Published: March 2009

Commercially developed 20% cold-worked P,Ti-modified 316 stainless steel claddings were irradiated as fuel pins in C-type irradiation rigs of JOYO under typical fast reactor conditions. The microstructural changes of irradiated claddings at temperatures around 500 °C were extensively analyzed using transmission electron microscopy. Void formation is closely related with M6C and G-phase precipitates and concomitant phosphide dissolution beyond the fast neutron fluence of 15x1026 n/m2. Such phase instability in the fuel pin cladding during the fast reactor operation is caused by the radiation induced solute segregation, and it mainly interpreted in terms of varying system sink strength due to dislocation and precipitate changes.
Effects of Low Temperature Irradiation on the Mechanical Properties of V-4Cr-4Ti
Authors: Alexander DJ , Snead LL , Zinkle SJ , Gubbi AN , Rowcliffe AF , Eatherly WS , Bloom EE
Published: March 2009

Neutron irradiation at low temperatures (100 to 275°C) to 0.5 displacements per atom causes significant embrittlement and changes in the subsequent room temperature tensile properties of V-4Cr-4Ti. The yield strength and microhardness at room temperature increase with increasing irradiation temperature. The tensile properties at room temperature show large increases in strength and a complete loss of work hardening capacity with no uniform elongation. Embrittlement, as measured by an increase in the ductile-to-brittle transition temperature, increases with increasing irradiation temperature, at least up to 275°C. It is shown that this embrittlement is not due to pickup of O or other interstitial solutes during the irradiation.
A Test Method for Measuring Liquid Penetration Through Fibrous Materials
Authors: Hussain MM , Tremblay-Lutter JF
Published: March 2009

Optimization of fabric structure for protective garment systems or glove liners requires knowledge of liquid penetration through fibrous materials also known as absorbency. To obtain reproducible absorbency results, liquid-sample contacting conditions are to be carefully monitored. A test equipment for measuring spontaneous uptake of liquids by fibrous materials has been developed which allows to control the conditions for initial contact between sample and the liquid. By continuously monitoring the approach of liquid to the sample surface and mass changes due to absorption, the first instance of liquid-sample contact and the initial uptake of liquid is simultaneously recorded on a sub-second time scale. Preliminary experimental data reported in this paper indicate that for reproducible absorbency test results initial contacting conditions should be properly established.
A Sweating and Moving Arm for the Measurement of Thermal Insulation and Water Vapour Resistance of Clothing
Authors: Weder MS , Zimmerli T , Rossi RM
Published: March 2009

There are many methods of measurement to analyse the specifications of fabrics like heat transfer and water vapour permeability. However, in practice, the air layers between the different fabrics fundamentally influence the wear comfort. With the sweating arm developed at EMPA, it is now possible to simulate the heat and moisture transfer under realistic conditions. The goal of this study is to analyse the interactions between the different parameters which influence the thermal and water vapour resistance. These parameters are basically the temperature, the degree of humidity, different widths of the sleeves, the pumping effect of the movable forearm and the wind velocity.

The study shows that the thermal insulation of the air layers is 5 to 50 times higher than the material itself. Wide sleeves have in average a 30% higher thermal insulation than narrow sleeves.

It could be prooved that thermal and moisture transfer do not correlate with each other: for one sample, even if the wide sleeve has a much higher thermal insulation than the narrow one, the water vapour resistance is much lower.
Influence of Humidity on the Radiant, Convective and Contact Heat Transmission Through Protective Clothing Materials
Authors: Rossi RM , Zimmerli T
Published: March 2009

The effect of moisture on the heat transmission through fourteen protective clothing assemblies has been analysed. The samples have been prepared in three different ways to simulate the accumulation of humidity either in the outer shell or in the inner layers. The behaviour of breathable water barriers has been investigated in particular. The assemblies have been exposed to several sources of heat (radiant, convective and contact heat) with different intensities. This study shows that for wet suits, there can be great differences in the protection given by the breathable barriers, compared with that given by coated materials. When exposed to high radiant or convective heat densities, breathable barriers offer a better protection, as a part of the humidity can be released to the outside and reduces the heat flux to the skin.
Methods for Assessing Protective Clothing Effects on Worker Mobility
Authors: Adams PS , Keyserling WM
Published: March 2009

Worker mobility in protective clothing can be assessed both objectively through range of motion (ROM) measurement, and subjectively through perceived freedom of movement. Ten male subjects performed a set of gross body movements while wearing coveralls that were undersized, appropriately sized, and oversized. ROM measurements were collected simultaneously with a universal goniometer and an electrogoniometer, and with a Leighton Flexometer and an electrogoniometer. Subjects rated the perceived impediment and comfort of each of nine test garments, using a Rating of Perceived Impediment, and a comfort rating system. The universal goniometer was found to be less expensive, easier to use, more sensitive, more durable, and less intrusive than either the Flexometer or the electrogoniometer. Subjective measures were positively correlated with each other, and with the objective measures. The subjective rating scales developed for this study can easily be adapted for use with ASTM F 1154-88, “Standard Practices for Qualitatively Evaluating the Comfort, Fit, Function, and Integrity of Chemical-Protective Suit Ensembles.”
Physiological Comparison of Fire Fighter Turnout Suits with and without a Microporous Membrane in the Heat
Authors: Mäkinen H , Ilmarinen R , Griefahn B , Künemund C
Published: March 2009

Physiological stress in fire fighters caused by a turnout suit with and without a water barrier composed of a microporous membrane was measured during simulated fire fighting work. Eight experienced fire fighters (23 – 47 years old) were randomly exposed to three wear trials consisting of a standardized treadmill test of 25 min of hard work at Ta of 50 °C, and P of 1440 W/m2, interrupted by a 25-min break at Ta of 22 °C, and followed by 30 min of moderate work at Ta of 40 °C, and P of 258 - 177 W/m2. Body temperatures and heart rate increased steadily during the work periods up to the individual heat tolerance limits. The body temperatures were higher when the suit with a membrane was worn. The difference in rectal temperature was not significant, but the difference in mean skin temperature was statistically significant at the end of the hard work (p=0.05). More sweat condensated in the underclothing, and the subjective evaluation of physical exertion, thermal discomfort and sensation were higher for the suit with the membrane, but only slight statistically significant differences were found. The corrected thermal insulation (ITcorr) and the water vapor permeability (Me) measured with the aid of a sweating thermal manikin were higher for the suit without the membrane.
Development of a Combination Thermal and Chemical Protective Ensemble for U.S. Navy Fire Fighting Applications
Authors: Stull JO , Connor M , Heath CA
Published: March 2009

U. S. Navy fire fighters routinely confront both thermal and chemical hazards during emergency response operations. To provide protection in these situations, a program was undertaken to develop, design, and fabricate fully-integrated protective ensembles that would provide protection against both thermal and chemical hazards. The program was divided into three phases--(1) surveying the protective clothing industry to identify candidate materials or material combinations based on requirements taken from existing National Fire Protection Association (NFPA) standards on protective clothing for structural fire fighting, proximity fire fighting, and hazardous chemical liquid splash protection; (2) developing new material and optimizing material combinations, and (3) fabricating prototype clothing ensembles using selected materials. The first phase provided a comprehensive survey of the thermal and chemical protective materials with testing of individual layers to fill in missing performance data. The second phase examined different combinations of existing materials to optimize the overall material configuration in terms of protection performance, comfort, fabrication feasibility and cost. This included the combination of radiant and chemical layers into a new single material. Of the material combinations examined, a 3-layer system with an inter-changeable outer shell was selected and used in the construction of prototype garments. The ensuing design was qualified to each of the three NFPA standards.
Flammability and Thermal Protection Testing of Long Underwear for Navy and Marine Corps Aircrew Use
Authors: Capecci TM , Swavely CB
Published: March 2009

Providing flammability and thermal protection to Naval and Marine Corps aircrew is a priority when developing and approving items for their clothing configuration. Currently, the components of the cold weather configurations are primarily made of Nomex®. It was the objective of this effort to determine if other natural or synthetic materials would be acceptable for use as the long underwear layer of these configurations in terms of flammability and thermal protection as well as increasing the comfort. Commercially available long underwear was purchased and tested for configuration compatibility, insulation value, immersed insulation value, moisture permeability, and flammability.
Alkali-Slag Cements For the Immobilization Of Radioactive Wastes
Authors: Shi C , Day RL
Published: March 2009

Alkali-slag cements consist of glassy slag and an alkaline activator and can show both higher early and later strengths than Type III Portland cement, if a proper alkaline activator is used. An examination of microstructure of hardened alkali-slag cement pastes with the help of XRD and SEM with EDAX shows that the main hydration product is C-S-H (B) with low C/S ratio and no crystalline substances exist such as Ca(OH)2, A1(OH)3 and sulphoaluminates. Mercury intrusion tests indicate that hardened alkali-slag cement pastes have a lower porosity than ordinary Portland cement, and contain mainly gel pores. The fine pore structure of hardened alkali-slag cement pastes will restrict the ingress of deleterious substances and the leaching of harmful species such as radionuclides. The leachability of Cs+ from hardened alkali-slag cement pastes is only half of that from hardened Portland cement. From all these aspects, it is concluded that alkali-slag cements are a better solidification matrix than Portland cement for radioactive wastes.
Performance of Cementitious Containment Barriers
Authors: Allan ML , Kukacka LE
Published: March 2009

Cementitious grouts and soil cements were evaluated for use as subsurface barriers to contain buried stabilized hazardous wastes. The environmnent of focus was arid, although the results may also be relevant to other environments. Optimization of the physical and mechanical properties of grouts and soil cements such as permeability, leach resistance, strength and shrinkage cracking was studied through variation of mix proportions. Material costs were compared with permeabilities to evaluate the relative cost effectiveness of the different barriers. Field scale demonstration is required to confirm that acceptable performance can be achieved in practice.
Using Mixture Experiments to Develop Cementitious Waste Forms
Authors: Spence RD , Anderson CM , Piepel GF
Published: March 2009

Mixture experiments are presented as a means to develop cementitious waste forms. The steps of a mixture experiment are (1) identifying the waste form ingredients; (2) determining the compositional constraints of these ingredients; (3) determining the extreme vertices, edge midpoints, and face centroids of the constrained multidimensional volume (these points along with some interior points represent the set of possible compositions for testing); (4) picking a subset of these points for the experimental design; (5) measuring the properties of the selected subset; and (6) generating the response surface models. The models provide a means for predicting the properties within the constrained region. This article presents an example of this process for one property: unconfined compressive strength.