bluuebunny/crossref_metadata_2025 huggingface dataset:
Irradiation Embrittlement of Reactor Pressure Vessel Steels due to Mechanisms Other than Radiation Hardening
Authors: Gurovich BA , Korolev YN , Kuleshova EA , Nikolaev YA , Shtrombakh YI
Published: March 2009

Data on Russian pressure vessel steels in unirradiated, irradiated and annealed conditions are presented. The experimental methods applied included impact testing, fractography, electron microscopy and Auger spectroscopy. Contributions from different mechanisms to radiation embrittlement were evaluated. These studies enabled us to conclude that the major contribution to radiation induced ductile-to-brittle transitions temperature shift in Russian pressure vessel steels is delivered by mechanisms other than radiation hardening.
Comparison of Different Experimental and Analytical Measures of the Thermal Annealing Response of Neutron-Irradiated RPV Steels
Authors: Iskander SK , Sokolov MA , Nanstad RK
Published: March 2009

The thermal annealing response of several materials as indicated by Charpy transition temperature (TT) and upper-shelf energy (USE), crack initiation toughness, KJc, predictive models, and automated-ball indentation (ABI) testing are compared. The materials investigated are representative reactor pressure vessel (RPV) steels (several welds and a plate) that were irradiated for other tasks of the Heavy-Section Steel Irradiation (HSSI) Program and are relatively well characterized in the unirradiated and irradiated conditions. They have been annealed at two temperatures, 343 and 454°C (650 and 850°F) for varying lengths of time. The correlation of the Charpy response and the fracture toughness, ABI, and the response predicted by the annealing model of Eason et al. for these conditions and materials appears to be reasonable. The USE after annealing at the temperature of 454°C appears to recover at a faster rate than the TT, and even “over-recovers” (i.e., the recovered USE exceeds that of the unirradiated material).
The Annealing Recovery of The Palisades Nuclear Power Plant Surveillance Material Using Weld Reconstitution
Authors: Williams JF , Kneeland JR , Server WL , Terek E , Lott RG , Friedman EN
Published: March 2009

Palisades Nuclear Power Plant had two of its already tested surveillance capsules used for an annealing recovery study. Previously tested weld metal Charpy specimen halves from Capsules W-290 and W-110, irradiated to fluences of 0.92 × 1019 and 1.59 × 1019n/cm2, respectively, were annealed, weld reconstituted, and tested for annealing recovery evaluation. Transverse plate Charpy halves from Capsule W-290 were also annealed, reconstituted, and tested. The weld material results from Capsule W-290 and W-110 showed measured transition temperature (TT) recoveries of 74% and 77% and upper shelf energy (USE) recoveries of 61% and 65%, respectively. The transverse plate material results from Capsule W-290 showed a TT recovery of 82% and an USE recovery of 11%. These results are discussed in the following paper.
Design of an Annealing Supplemental Surveillance Program for the Palisades Reactor Pressure Vessel
Authors: Server WL , Lott RG , Kneeland JR , Hanson JL
Published: March 2009

A decision to thermally anneal the Palisades reactor pressure vessel (RPV) was made in 1995 by Consumers Power Company. The anneal is currently planned for 1998 and will be conducted using an indirect gas-fired chamber method which will radiantly heat the RPV beltline region to nominally 454°C (850 °F) for a one week (168 hour) hold time. The recovery of Charpy impact toughness properties after annealing will be ascertained by using a combination of a recovery model developed by Eason et al. and actual validation measurements on Palisades plant-specific surveillance materials. The use of plant-specific surrogate materials (from retired steam generators) and original surveillance program materials requires the development of a supplemental surveillance program focused at both recovery and reirradiation embrittlement. The post anneal re-embrittlement properties are crucial for continued plant operation, and the current use of a lateral shift model for re-embrittlement trending is expected to be conservative. The program also uses reconstituted Charpy specimens and new surveillance capsules following the program format developed for ASTM Standard Guide for In-Service Annealing of Light-Water Cooled Nuclear Reactor Vessels, ASTM E 50986 (1991), 1996 revision currently in ballot. This supplemental surveillance program should provide adequate toughness property definition for the Palisades key materials such that operation can be completed to the end of operating license and beyond if license renewal is pursued.
Nondestructive Evaluation of Neutron Irradiation Embrittlement for Reactor Vessel Steel by Magnetomechanical Acoustic Emission Technique
Authors: Maeda N , Yamaguchi A , Saito K , Hirasawa T , Komura I , Chujou N
Published: March 2009

A modified magnetomechanical acoustic emission (MAE) technique denoted Pulse MAE, in which the magnetizing current has a rectangular wave form, was developed as an NDE technique. Its applicability to the radiation damage for reactor pressure vessel steel was evaluated.

The reactor pressure vessel steel A533B base metal and weld metal were irradiated to the two fluence levels: 5 x 1022 and 3 x 1023 n/m2 at 288 °C. One side of the specimen was electropolished after irradiation. Pulse MAE signals were measured with a 350 kHz resonance frequency AE sensor at the moment when the magnetizing voltage is applied from zero to the set-up value abruptly. The AE signals were analyzed and the peak voltage Vp was determined for the measuring parameter.

The peak voltage Vp showed the tendency to increase monotonically with increasing neutron fluence. The relationship between the Vp and mechanical properties such as yield stress, tensile strength and Charpy transition temperature were also obtained. The Pulse MAE technique proved to have the possibility to detect and evaluate the neutron irradiation embrittlement. The potential of the Pulse MAE as an effective NDE technique and applicability to the actual components are discussed.
Detection of Irradiation Embrittlement of Low-Alloy Steel for Nuclear Reactor Pressure Vessels Using a Probe Type Eddy Current Sensor
Authors: Maeda N , Yamaguchi A , Sugibayashi T , Kohno K
Published: March 2009

This report describes the results of studies made for the purpose of detecting the irradiation embrittlement of low-alloy steel used for nuclear reactor pressure vessels. For the method of using eddy current to detect material degradation, the device and the sensor employed are light in weight and compact in size, allowing testing without contact. In this study the frequency of input current to the excitation coil is changed in steps of 1 kHz. The output signal is processed by phase detection method, and displayed on a complex plane. It depicts a trajectory as the frequency is changed. To extract features of the trajectories, averaged radius and averaged phase angle are defined and plotted as function of neutron fluence or ductile-brittle transition temperature. Experiment shows that the averaged phase angle and transition temperature decrease as the neutron fluence is increased. Behavior of the averaged phase angle is interpreted employing magnetic permeability and electric conductivity of the test specimens. It becomes clear that electric conductivity decreases as the neutron fluence is increased.
The Effect of Ordering on Radiation-Induced Segregation in Austenitic Iron- and Nickel-Base Alloys
Authors: Allen TR , Was GS
Published: March 2009

Comparison of radiation-induced segregation (RIS) measurements from austenitic iron- and nickel-base alloys with calculations using the Perks vacancy-driven RIS model have shown that chromium segregates slower and iron segregates faster than expected from high temperature diffusion measurements. The effect is more pronounced in nickel-base alloys. The segregation process is affected by short range ordering forces and the ordering is strongest in nickel-base alloys. Since nickel enriches and chromium depletes in all iron-chromium-nickel alloys under irradiation, a tendency to form nickel- chromium pairs reduces the chromium segregation, especially in nickel-base alloys. In this work, Perks' model is altered to include ordering energies, and the calculated RIS is compared to segregation measurements from iron-chromium-nickel alloys irradiated with 3.2MeV protons. A single set of ordering energies, an attractive potential between nickel and chromium and a repulsive potential between nickel and iron are used for each alloy. Calculations that do not include ordering overpredict the chromium depletion by up to 4 at% in iron-base alloys and 8 at% in nickel-base alloys. Calculations that include the ordering reduce the difference between model predicted and measured chromium concentrations to less than 2 at% for most iron- and nickel-base alloys.
Microstructures in Neutron Irradiated Fe-Cr-Ni-P-Ti Model Austenitic Alloys Doped with 10B
Authors: Muroga T , Watanabe H , Yoshida N , Kurishita H
Published: March 2009

Fe-16Cr-17Ni ternary alloy and those with addition of 0.024P, 0.1P and 0.1P+0.25Ti were irradiated with fast neutrons in FFTF/MOTA at 793 K and 874 K to 33 dpa and 60 dpa. For the purpose of investigating helium production effect, two levels of 10B were doped for each alloy. The microstructures and their relation with tensile properties were examined. The yield stress change was correlated with the density of phosphide precipitates.
Comparison of Irradiation Creep and Swelling of an Austenitic Alloy Irradiated in FFTF and PFR
Authors: Garner FA , Toloczko MB , Munro B , Adaway S , Standring J
Published: March 2009

Comparative irradiation of identically constructed creep tubes in the Fast Flux Test Facility (FFTF) and the Prototypic Fast Reactor (PFR) shows that differences in irradiation conditions arising from both reactor operation and the design of the irradiation vehicle can have a significant impact on the void swelling and irradiation creep of austenitic stainless steels. In spite of these differences, the derived creep coefficients fall within the range of previously observed values for 316 SS.
Irradiation Creep in Nickel Containing and in Manganese Containing Stainless Steel Alloys
Authors: Hausen H , Schüle W
Published: March 2009

This is a final report on the results of measurements of neutron irradiation creep which have been performed in non-instrumented creep rigs (Trieste) on many different stainless steel alloys during the last fifteen years in high flux positions in the High Flux Reactor (HFR) at Petten. The creep elongations were measured in hot cells during reactor shut down periods. A few investigations of the creep elongation were performed in fully instrumented creep rigs (Crisp).

All the materials were irradiated in the as-received state, which was usually a type of solution-annealed state, after annealing at 400, or at 600, or at 800°C, and after 20% cold work. The irradiation temperature ranged from 300 to 500°C and the applied stresses were between 25 and 300 MPa.

The variations in length found up to irradiation doses of about 5 dpa are mainly attributed to the formation of radiation-induced microstructural changes, which are connected either with increases or with decreases in the volume of the materials. We are advancing an interpretation of the data which is not without contradictions. We believe that among the many microstructural changes only the formation of carbides, which is connected with an increase in volume, and only the formation of α-ferrite, which is connected with a decrease in volume, are of importance. The α-ferrite phase is very brittle, decreasing the ductility of the stainless steels dramatically.

An almost thermal equilibrium state of microstructure while irradiating with high energy particles is obtained after about 5 dpa, depending also on the irradiation temperature. The increase in length obtained for doses larger than 5 dpa is attributed mainly to irradiation creep. The normalized creep rates for all stainless steel materials are almost equal in HFR, ORR, and in EBR II. The creep rates increase linearly with stress and flux, and they are slightly dependent on the irradiation temperature (Qirr= 0.132 eV) for irradiation temperatures below about 450°C. For irradiation temperatures above 450°C a contribution of thermal vacancies to irradiation creep is noticed and the irradiation creep rates can no longer be ascribed to a simple irradiation creep relation.
A Reevaluation of Helium/dpa and Hydrogen/dpa Ratios for Fast Reactor and Thermal Reactor Data Used in Fission-Fusion Correlations
Authors: Garner FA , Greenwood LR , Oliver BM
Published: March 2009

The 59Ni isotope produced by the 58Ni (n,γ) reaction has three highly exothermic reactions, (n,α), (n,p), and (n,γ). These reactions contribute to the displacement damage and two of them can generate significant amounts of helium and hydrogen. The production of helium in the Experimental Breeder Reactor-II (EBR-II) at high neutron exposure has been measured and found not to include a significant contribution from 59Ni in those core volumes where most material's data were generated. This is in contrast to a significant 59Ni contribution that occurs in the softer below-core areas of the Fast Flux Test Facility (FFTF).

The often overlooked 59Ni contribution to hydrogen generation is of particular importance when considering neutron spectra with a substantial thermal neutron component, however. Inclusion of the (n,p) and (n,γ) recoil events in the dpa damage calculations requires only a 3% correction to the previously published value, indicating that most of the damage arises from the (n,α) reaction.
The Dependence of Swelling on Phosphorus Content in Stainless Steels Containing High Silicon Levels
Authors: Reinhart DE , Garner FA
Published: March 2009

The last segment of a four-part investigation on the influence of phosphorus and silicon on neutron-induced void swelling of austenitic stainless steels has been completed. This final segment explored the influence of these elements on the macroscopic swelling of developmental alloys irradiated in the 20% cold-worked condition in the Fast Flux Test Facility. As was also seen in the previous three series, a non-monotonic swelling response with respect to phosphorus concentration is sometimes observed. Therefore it is not safe to assume that phosphorus and/or silicon additions will always reduce swelling.
Neutron Irradiation Creep at 100°C on 316L, AMCR, and Welded 316L Stainless Steel Alloys
Authors: Hausen H , Schüle W
Published: March 2009

We performed measurements on the elongation of many different austentic stainless steel alloys irradiating at 100°C in a low flux channel of the High Flux Reactor at Petten varying the applied stress between zero and 300 MPa. We irradiated in total 98 samples in two irradiation rigs. Of these samples only 26 samples could be tested up to a dose of 2.1 dpa, and 13 samples up to a dose of 0.21 dpa. The steels tested are listed in Table I. In the second irradiation rig four TIG-welded samples and one EB-welded sample were irradiated.

We found that the length of the samples increased up to an irradiation dose of 0.11 dpa and then either decreased or increased slightly depending on the magnitude of the applied stress. We attributed the increase in length to the volume change due to the formation of carbides and to the accommodation of carbides to the applied stress. The decrease of the length with irradiation time is attributed to the formation of brittle α-ferrite. The amount of α-ferrite formed increases with decreasing irradiation temperature and increases with decreasing applied stress.

Eight samples broke during irradiation in 8 columns or stems in two rigs before the first elongation test at 0.11 or 0.21 dpa could be performed. Irradiation of 343 samples of the same materials in the last fifteen years at temperatures between 300 and 500°C did not cause fracture.
Effect of Radiation-Induced Segregation on Precipitate Stability and Swelling in Irradiated Alloys
Authors: Pechenkin VA , Epov GA , Stepanov IA , Konobeev YV
Published: March 2009

The radiation-induced segregation of alloy components near point defect sinks with a particular attention to Fe-Cr-Ni based alloys is analyzed. The influence of point defect generation rate on temperature ranges of stability for radiation-retarded M23C6 and radiation-induced Ni3Si precipitates in austenitic stainless steels is considered. A method of calculation of steady-state segregation-induced bias in irradiated binary alloys, taking into account Kirkendall forces and drift forces caused by point defect migration and formation energy gradients near sinks, is proposed. Contributions of various forces to the bias in Fe-Cr-Ni and V-Fe alloys are evaluated. The effect of void-precipitate association on swelling is analyzed. The radiation-induced segregation of components and segregation-induced bias for motionless and moving grain boundaries in a Fe-Cr-Ni alloy are calculated by solving the set of coupled diffusion equations for component and point defect concentrations.
The Consequences of Helium Production and Nickel Additions on Microstructural Development in Isotopically Tailored Ferritic Alloys
Authors: Gelles DS
Published: March 2009

A series of alloys have been made adding various isotopes of nickel in order to vary the production of helium during irradiation by a two step nuclear reaction in a mixed spectrum reactor. The alloys use a base composition of Fe-12Cr with an addition of 1.5% nickel, either in the form of 60Ni which produces no helium, 59Ni which produces helium at a rate of about 10 appm He/dpa, or natural nickel which provides an intermediate level of helium due to delayed development of 59Ni. Specimens were irradiated in the HFIR at Oak Ridge, TN to 7.5 dpa at 300 and 400°C. Microstructural examinations indicated that nickel additions promote precipitation in all alloys, but the effect appears to be much stronger at 400°C than at 300°C. There is sufficient dose by 7 dpa (and with 2 appm He) to initiate void swelling in ferritic/martensitic alloys. Little difference was found between response from 59Ni and natural nickel. Also, helium bubble development for high helium generation conditions appeared to be very different at 300 and 400°C. At 300°C, it appeared that high densities of bubbles formed whereas at 400°C, bubbles could not be identified, possibly because of the complexity of the microstructure, but more likely because helium accumulated at precipitate interfaces.
Impact Behavior of Low Activation Steels at 30 dpa
Authors: Hamilton ML , Schubert LE , Gelles DS
Published: March 2009

Impact tests were performed on one-third size specimens of six low activation steels developed for structural applications in fusion reactors. Specimens were irradiated to ∼30 dpa at ∼375°C in the Fast Flux Test Reactor. Comparison of the results with those of control specimens and specimens irradiated to 10 dpa indicates that degradation in the impact behavior appears to have saturated by ∼10 dpa in at least four of these alloys. The most promising of the alloys, a 7.5Cr-2W alloy referred to as GA3X, exhibited the best impact properties, with no increase in ductile to brittle transition temperature or decrease in upper shelf energy between 10 and 30 dpa. Fractography supports the impact test results.
Electron Microscopy of Precipitation and Age Hardening in Fe-0.6Cu Model Alloy
Authors: Kawanishi H , Suzuki M
Published: March 2009

Conventional electron microscopy was done on thermally-aged Fe-0.6 wt.% Cu alloy to study the precipitation behavior of copper in α-iron. The alloy was aged at 500°C for 1000 h after water-quenching at 850°C. Transmission electron microscopy observations showed that the disk-shaped copper precipitate of a fcc-structure and ∼0.4 nm in thickness was formed with water-quenching, where there was a Kurdjumov-Sachs orientation relation between the precipitate and the matrix. Aging was proved to reduce the density and diameter of the precipitates and to increase their thickness. Peak hardness was achieved at 100 h-aging. The precipitate was identified to be still disk-shaped (∼2 nm in thickness and ∼7 nm in diameter) and coherent with the matrix after 1000 h-aging.

In addition to copper precipitates, the small-sized particles of 1 to 2 nm in diameter were recognized to be uniformly distributed through the matrix, where their density was estimated to be on the order of 1023/m3. The particle was considered to reasonably be Fe3O4 from the analysis of the selected area diffraction patterns and the compositions of the alloy. Fe3O4 was believed to have formed during alloying and to have been less effective for age-hardening.

By taking account of the interfacial energy between the matrix and copper precipitate (chemical hardening mechanism), an estimation was tentatively made to explain the hardening behavior with aging of the alloy. Assuming the interfacial energy of 1000 erg/cm2, the results showed that the flow stress was increased by ∼29 kg/mm2 due to copper precipitation at 100 h-aging, followed by softening with further aging. The increase in the thickness of copper precipitates was concluded to be the most important factor governing the strength of the alloy during aging.
Radiation-Enhanced Diffusion of 63Ni in Nickel and in Copper
Authors: Schüle W
Published: March 2009

Radiation-enhanced diffusion coefficients of 63Ni in nickel and in copper were determined between -100°C and +500°C after an irradiation with 1.85 MeV electrons which were obtained from a Van de Graaff generator. The diffusion coefficients were obtained by counting the activity of successive layers from the surface of single crystals which were removed by means of sputtering. The dislocation density of the crystals was smaller than d = 10-4 cm-2 and the evenness of the surfaces of the crystals was better than 20 Å.

It was found that the radiation-enhanced diffusion coefficients were approximately independent of the irradiation temperature in the “low” temperature regime, i.e. below about 100°C, and about 1.3·10-20 cm2·s-1 and 1.1·10-20 cm2·s-1 for nickel and copper, respectively. The replacement collision sequence number of dynamic crowdions was derived from these results and values of N ≈ 50000 and N ≈ 40000 were obtained for nickel and copper, respectively. The same values were obtained previously from measurements of the radiation damage rate.

The radiation-enhanced diffusion coefficients were obtained for “high” irradiation temperatures, dependent on the irradiation temperature, and were approximately in agreement with those obtained by computation assuming that the migration activation energy of interstitials was EIIM = 0.869 eV and EIIM = 0.584 eV for nickel and copper, respectively (for K = 6.3·10-10 dpa·s-1).

Dynamic crowdions can dissolve e.g. precipitates, and three-dimensionally migrating point defects can usually form precipitates.
The Effects of Irradiation on the Mechanical Properties of 6061-T651 Aluminum Base Metal and Weldments
Authors: Alexander DJ
Published: March 2009

The aluminum alloy 6061-T651 was a candidate material for several critical components of the proposed Advanced Neutron Source (ANS) research reactor. In order to determine the effects of irradiation on the mechanical properties of this alloy, irradiations have been conducted in the High Flux Isotope Reactor under conditions that are similar to those predicted for the ANS. Compact and tensile specimens of 6061-T651 aluminum were irradiated at a nominal temperature of 95°C to a thermal neutron fluence of approximately 8 × 1026 m-2 (<0.625 eV) for comparison with earlier data from material irradiated to a fluence of 1026 m-2. This lower fluence resulted in a small increase in the yield and ultimate tensile strengths, and a slight decrease in the elongation. However, the fracture toughness was not significantly affected at this fluence except at the highest test temperature of 150°C. Irradiation to the higher fluence resulted in a further increase in the yield and ultimate tensile strengths, and a further decrease in the total elongation. The fracture toughness showed little effect of the higher level of irradiation, except at the highest test temperature of 150°C, where the toughness showed an additional decrease. Weldments made with 4043 filler metal were irradiated to 2 × 1026 m-2. The yield and ultimate tensile strengths of the weld metal were much lower than the base metal in the unirradiated condition, but more than doubled after irradiation. The toughness of the unirradiated weld metal was very high, and it decreased significantly after irradiation, becoming similar to the unirradiated base metal.
Irradiation Induced Growth and Microstructure Evolution of Zr-1.2Sn-1Nb-0.4Fe Under Neutron Irradiation to High Doses
Authors: Nikulina AV , Shishov VN , Peregud MM , Tselischev AV , Shamardin VK , Kobylyansky GP
Published: March 2009

Zirconium alloy components subjected to long-term operation and high doses in thermal reactors need to be highly irradiation resistant to provide integrity of components, primarily, their geometrical sizes. Transmission and scanning electron microscopy, energy dispersive X-ray microanalysis used to investigate thin foils and extraction replicas of irradiated zirconium, Zr-1Nb (E110) and Zr-1.2Sn-1Nb-0.4Fe (E635) alloys allowed us to analyze the evolution of their microstructure under neutron irradiation. The experimental irradiations that were conducted at 350°C to 1027 n/m2 (E ≥ 0.1 MeV) show that the most irradiation resistant alloy proved to be a multicomponent E635 alloy. It is not essentially subject to growth. Dislocation structure and phase composition were studied as interrelated to different stages of irradiation induced growth. The accelerated growth correlates with a high density of basal — plane 〈c〉-component dislocations.
In-Situ Radio-Luminescence from Sapphires Under Fission Reactor Irradiation
Authors: Shikama T , Kakuta T , Narui M , Sagawa T , Jensen BFH , Nakazawa S , Kayano H
Published: March 2009

Radio-luminescence from the sapphire was detected in-situ under the reactor irradiation using the silica core optical fiber. The radio-luminescence peaks at 420, 690, and 860nm, and broad band in 700–1200nm were identified. However, these radio-luminescence peaks and band became obscure as the reactor power went up, due to the increase of the specimen temperatures and to the interference of the strong radio-luminescence from the silica core optical fiber itself. The effect of the applied electric field on the radio-luminescence was studied. Change was observed due to the electric field but it was very small. Further study and a better-controlled experiments will be needed to clarify the effect.
The Effects of Constraint, Loading Rate and Irradiation on the Toughness-Temperature Behavior of a V-4Cr-4Ti Alloy
Authors: Odette GR , Donahue E , Lucas GE , Sheckherd JW
Published: March 2009

The influence of loading rate and constraint on the effective fracture toughness as a function of temperature [Ke(T)] of the fusion program heat of V-4Cr-4Ti was measured using subsized, three point bend specimens. The constitutive behavior was characterized as a function of temperature and strain rate using small tensile specimens. Data in the literature on this alloy was also analyzed to determine the effect of irradiation on Ke(T) and the energy temperature (E-T) curves measured in subsized Charpy V-notch tests. It was found that V-4Cr-4Ti undergoes “normal” stress-controlled cleavage fracture below a temperature marking a sharp ductile-to-brittle transition. The transition temperature is increased by higher loading rates, irradiation hardening and triaxial constraint. Shifts in a reference transition temperature due to higher loading rates and irradiation can be reasonably predicted by a simple equivalent yield stress model. These results also suggest that size and geometry effects, which mediate constraint, can be modeled by combining local critical stressed area σ*/A* fracture criteria with finite element method simulations of crack tip stress fields. The fundamental understanding reflected in these models will be needed to develop Ke(T) curves for a range of loading rates, irradiation conditions, structural size scales and geometries relying (in large part) on small specimen tests. Indeed, it may be possible to develop a master Ke(T) curve-shift method to account for these variables. Such reliable and flexible failure assessment methods are critical to the design and safe operation of defect tolerant vanadium structures.
Effects of Helium on Void Swelling Behavior of Vanadium Alloys Using Dual Ion Beam Irradiation
Authors: Iwai T , Sekimura N , Garner FA
Published: March 2009

In previous experiments we utilized irradiation in FFTF/MOTA (Fast Flux Test Facility / Materials Open Test Assembly) to investigate the swelling behavior of vanadium alloys and have applied the boron-doping technique to study the effect of helium. In this study, dual ion beam irradiation experiments were carried out to distinguish the helium effect from the chemical effect of dopant boron on the swelling behavior of vanadium alloys containing undersized atoms such as iron that are known to eliminate the swelling resistance to void swelling of vanadium alloys. Displacement damage by nickel ions without simultaneous helium implantation makes nucleation of cavities occur near grain boundaries rather than in the matrix in V and V-5Fe. The simultaneous implantation of helium ions strongly assists nucleation of cavities in the matrix to form a uniform distribution of cavities in the matrix of both V and V-5Fe. Boron additions also affect the swelling behavior of these alloys.
Specification of Motorcyclists' Protective Clothing Designed to Reduce Road Surface Impact Injuries
Authors: Woods RI
Published: March 2009

Crash damage on motorcycling clothing has been analysed on 100 suits. The information has been used to define four zones on clothing that require different performance characteristics. Zone 1 is subject to severe impacts and abrasion, Zone 2 to severe abrasion and stress damage, and Zone 3 is at moderate risk of abrasion damage. Zone 4 is at low risk of road contact, and important ergonomic features such as ventilation panels may be fitted here. Performance requirements of the four zones are proposed based on the Belt impact abrasion test, burst testing and impact cut testing. Impact protection and its specification are discussed.
Comparison of Two Methods to Evaluate the Resistance of Protective Gloves to Cutting by Sharp Blades
Authors: Lara J , Turcot D , Daigle R , Payot F
Published: March 2009

Two methods for evaluating the cut resistance of gloves were compared: one developed at ITF-Lyon (Institut Textile de France) and one developed at the IRSST (Institut de recherche en santé et en sécurité du travail du Québec) in Montreal, Canada. The ITF method uses a circular blade with a pressure of 5 N applied on the blade. The blade speed is sinusoidal with a maximum of 100 mm/s. The value to be measured is the number of cycles to cut the material and is compared with that of a reference material. The IRSST method uses a straight blade and the pressure is applied on the sample holder. Series of tests using at least two different weights must be performed at a constant blade speed. The cut resistance for the IRSST method is measured as the load required to cut the material at a 10-mm blade displacement. Eighteen glove materials of different levels of cut resistance were compared. With uniform materials such as neoprene, no variability is observed with the ITF method, while a coefficient of variation of approximately 10% is observed with the IRSST method. These results may be due to different sensitivities of the test methods. The ranking of cut resistance obtained with both methods can be considered as equivalent and the results are comparable with a correlation coefficient r of 0.89.
Belt Abrader Impact Abrasion Testing of Leathers and Fabrics Used in Motorcycle Riders' Clothing.
Authors: Woods RI
Published: March 2009

A belt abrasion tester is described. It consists of an electric motor which drives an OP 60 aluminium oxide grit belt at 8 m/s. The upper horizontal run of the belt is supported by a 25 mm thick steel plate. The sample is fixed to a rigid horizontal pendulum arm pivoted two metres from the sample. The arm can be raised so that the sample is up to 1.5 m above the belt surface before it is released to fall onto the moving belt. The sample face that is abraded is 50 mm in diameter. The static force between the sample and the belt is 49 N or 25 kPa. Two drop heights are normally used, 1.0 m to simulate abrasion in the initial impact and sliding phase and 50 mm to simulate only the sliding phase of an accident. The time to abrade a hole in the sample is measured using two trigger wires, one in front of the sample and one behind. These are connected via low-voltage relays to an electronic timer. Abrasion times of leathers and fabrics are generally 0.2–10 s. Relative abrasion resistance is calculated by reference to the abrasion time of a standard cotton canvas.
Factors Influencing the Performance of Chain Saw Leg Protective Devices and Its Measurement
Authors: Arteau J , Arcand J-F , Turcot D
Published: March 2009

Protective trousers and protective chaps are worn by chain saw operators to protect their legs. The protection is given by protective pads sewn on the clothing. These pads are an assembly of layers of fabrics made form high-strength fiber. Protective pads are tested using a gas powered chain saw according to the CAN/BNQ 1923-095 and the ASTM F1414-92a test methods which are similar. The threshold stopping speed is the performance criterion measured. The TSS is the largest motor or chain speed at which no cut through occurs.

Since 1987, the CAN/BNQ 1923-095 test method has been used. From the test results, several observations are made and useful conclusions are drawn on the test method, on the mechanisms of protection and on the trousers and chaps.

On the test method: the chain sharpness, the chain type, the angles of cutters, the condition of the clutch, the gasoline and oil mixture and its stability are factors that affect significantly the measurement. The most important one is the chain. The findings are useful for any cut resistance test method. The test method is reliable and gives repetitive results.

Three main mechanisms of protection are observed. They are: cut resistant material, clogging (jamming) material and chain stop material. Description and examples of each are given.

Test results on trousers and chaps were performed on North American and European products before implanting a certification program in Quebec and in Canada. The results show large variation in the performance of leg protective devices. Some are excellent, some are very bad offering nearly no protection even if labelled “safety trousers”. Tests and analysis of the textile show variation in the number of layers, in the fabrics and a lack of mechanical stability under washing. These facts support to need of third party certification program. In conclusion, the test method is reliable, sensitive to changes in the protective pads or changes in the chain conditions and giving always the same ranking. Three mechanisms of protection are identified and their use on specific clothing is suggested. End users are now able to find performing products that will protect adequately.
A Review of the ASTM F 1001 Battery of Chemicals and Its Effect on the Chemical Protective Clothing Industry
Authors: Stull JO
Published: March 2009

Since the introduction of Guide F 1001, the chemical protective clothing industry has responded in several ways. A number of clothing manufacturers exclusively report permeation resistance results to ASTM F 1001 battery chemicals, while others use the battery chemicals as a subset of a larger data base on material chemical resistance. The ASTM F 1001 standard has been embraced and used most by chemical protective clothing manufacturers to highlight advances in product chemical resistance. The ASTM F 1001 chemicals are also specified as the minimum battery for chemical resistance testing with the NFPA standards on chemical protective suits and garments. This paper reviews the original basis for the selection of ASTM F 1001 chemicals and provides useful data on test chemicals which can aid the interpretation of chemical resistance test results. The use of the standard within the protective clothing industry is also examined, specifically indicating how battery results are used for representing different types of products.
Reproducibility of Pesticide Spray Penetration Tests with the UNCG-Clemson Spray Box
Authors: Sun S , Oakland BG , Dodd RB
Published: March 2009

Development and refinement of laboratory tests to prescreen barrier fabrics and predict performance in the field are important, since field studies are 1) expensive and time-consuming, and 2) variables such as wind, humidity, and sunlight are impossible to control. The purpose of this study was to determine the reproducibility of the spray penetration tests to prescreen fabrics as barriers to pesticide penetration with the UNCG-Clemson spray box. Tests were made to measure the effects of two exposure times, six pressures, and four sample locations on the deposition of water sprayed on gauze samples positioned on each of four vertical arm test sites. The highest reproducibility of the UNCG-Clemson spray box was found in a spraying condition at 206.8 or 275.7 kPa and 85 seconds exposure with water (CV=4%, SD=0.0041) and 0.125% atrazine (AAtrex Nine-O®) solution.
Solid-State Transition of Pesticide from Protective Clothing to Skin
Authors: Yang Y , Li S
Published: March 2009

Fractional transition of pesticide, the transition of the pesticide due to rubbing, from protective clothing to skin was investigated by using an AATCC standard crockmeter. Two herbicides, atrazine and metolachlor, were studied together with three protective clothing materials: cotton, polyester, and polyester/cotton (65/35) blend. Pig skin, with and without hair, was used to simulate human skin for the study of pesticide transition. The effect of water and perspiration on frictional transition of pesticide was also examined. Our experiment showed that up to 38% of the pesticide could transfer from contaminated apparel to the skin through rubbing. The frictional transition of pesticide from protective clothing to other fabrics may not represent the real transition from protective clothing to skin even though protein textiles are used to imitate skin.
Clothing Contamination Resulting from Greenhouse Spraying of Pesticides
Authors: Obendorf SK , Stone JF , Derksen RC , Ravichandran V , Coffman CW , Koh Y , Sanderson JP , Stahr HM
Published: March 2009

New spray technology involving charged droplets has been evaluated for improved treatment efficiencies. Our objectives were to further the investigation of contamination of non-targeted areas by measuring the pesticide deposition on applicator clothing during greenhouse spraying by Electrostatic Spraying System® (ESS) and DRAMM® sprayers, comparing deposition patterns and assessing the performance of Comfort-Gard™II® coveralls in a limited exposure situation. The deposition from the two sprayers was analyzed in two ways: visual analysis using a fluorescent dye tracer and chemical analysis of two insecticides, Orthene® and Tame®, using gas chromatography. The highest deposition observed with the fluorescent dye was on the gloves. The outer surfaces of the Comfort-Gard II coveralls were contaminated with both pesticides. Pesticide deposition was similar for the high concentration/low volume ESS sprayer and the low concentration/high volume DRAMM sprayer. Pesticide contamination at different locations on the coverall was highly variable with the back and chest of the torso having the highest concentrations. Under these test conditions with the higher concentration mix, pesticide was observed on the collection garment on the upper and lower arm with the Dramm sprayer and on the chest front for the ESS sprayer, thus we conclude that more lengthy and thorough investigations of Comfort-Gard II performance are needed.
Estimated Costs of Home Laundering Pesticide Contaminated Reusable Clothing
Authors: Olson WW
Published: March 2009

This study estimated the per load cost of laundering clothing worn for pesticide application, using recommended laundry practices and home equipment. Costs were based on a top-load (vertical axis) clothes washer with a 94.6 L (25-gallon) fill, hot wash with cold rinse, fuel costs of $0.0824/kWh and $5.71/GJ ($0.6024/therm), and 1 1/2 times the amount of detergent recommended by the detergent manufacturer for a normal load. The estimated cost per load ranged from $0.72 to $1.32 for depreciation of the clothes washer, and for fuel and detergent. The estimated cost of a no-load wash cycle to clean the washer ranged from $0.58 to $1.09.
A Nondestructive Inspection Method to Determine Fatigue in Chemical Protective Suit and Shelter Materials
Authors: Bray AV , Stull JO
Published: March 2009

This study demonstrated the initial feasibility of using nondestructive inspection (NDI) penetrant-based methods for detecting fatigue cracks and similar breaches of integrity in chemical protective clothing and shelter materials. Such a technique could provide a simple but direct means of determining remaining life in chemical protective suits and shelters. Chemical protective materials range from coated fabrics to highly engineered multi-layer, multi-film composites. Selected materials were tested using off-the-shelf penetrant systems normally used for inspecting metallic surfaces. Microscopy, biopenetration, and chemical permeation were used to verify the results of penetrant NDI testing. The selected materials were fatigued using a “Gelbo flex tester” to simulate wear and repeated flexing. Controlled diameter and depth punctures were also used to induce material defects.

Fluorescent penetrants applied to Teflon/Nomex or fiberglass/Teflon composite laminates formed large florescent halos around defects which had breached the top layer of Teflon. These easily observed halos show through the translucent coating and were the result of penetrant wicking into the fibrous center layer. The detection success for defects which breached the outer Teflon layer was virtually 100%. Halo indications were typically 7 mm in diameter for a 0.12 mm puncture defect--representing an amplification factor of over 50. When a fatigued sample failed biopenetration, the same fatigue level sample produced positive penetrant testing results. Penetrant NDI results also correlated well with chemical permeation results. Fluorescent indications were observed for controlled punctures which were half as deep as the material thickness. Other types of chemical protective suit and shelter materials were tested, including PVC and butyl coated fabrics. while halos occurred in some of these materials, background coloring of other materials caused interference with the technique.
Evaluation of Clothing Heat Transfer by Dry and Sweating Manikin Measurements
Authors: Holmér I , Nilsson H , Meinander H
Published: March 2009

Due to effects of, for example, body movements and wetting on clothing heat transfer, measures taken with a standing, static, “dry” manikin are not likely to predict very accurately thermal protection in a real situation. In a proposed European standard (prEN342 Protective clothing against cold), measurement of thermal insulation is made with a “walking” manikin in order to account for some of the dynamic effects. Determination of evaporative resistance with a sweating manikin is still subject to research. In this investigation, five ensembles (one, two and three-layer ensembles) were investigated a) in human wear trials with analysis of heat fluxes, b) by measurements with a dry, standing and walking manikin and c) by measurements with a standing, sweating manikin. Total thermal insulation and evaporative resistance during actual walking was reduced by 20–45 %. Total insulation reduced less with more layers. Subtracting effects on the surface air layer revealed that the wind exerted a lesser effect as the insulation value increased. Wind and “walking” effects were less than 5–10 % for a three layer winter clothing. Evaporation efficiency measured with a sweating manikin provided a similar ranking of ensembles as direct measurements with subjects. Dynamic measurements of heat transfer properties appear to present reliable and realistic values for clothing thermal performance and should be used with prediction models and assesment methods of thermal stress.
Functional Fit Evaluation to Determine Optimal Ease Requirements in Chemical Protective Gloves
Authors: Tremblay-Lutter JF , Weihrer SJ
Published: March 2009

A functional fit evaluation of the Canadian Forces (CF) chemical protective lightweight glove was undertaken in order to quantify the amount of ease required within the glove for optimal functional fit. The results demonstrated that a negative ease in glove digit length of 0.35 cm and a negative ease in glove digit girth of 0.19 cm provided optimal functional fit; while a positive ease of 1.75 cm in glove palm girth was optimal. It was concluded that anthropometric data should not be directly translated into glove design dimensions. Modification of the specifications from hand dimensions, which incorporates consideration of ease, must occur in order to develop gloves which enable effective function and provide a comfortable fit.
The Need for Research on Human Factors Regarding Personal Protective Devices in the Cold Environment
Authors: Abeysekera JDA , Bergquist K
Published: March 2009

The human factors or wearability needs of personal protective devices (ppd) and clothing (ppc) worn in the cold environment become more important as they must compromise with, and be adapted to, the clothing worn for cold protection. The occupational risks among outdoor workers in the cold can be aggravated if the wearability demands of ppd are not met. Failure to adequately meet user needs in currently used ppd in the cold environment has resulted in discomfort, injury, non-use and performance decrement among outdoor workers, particularly in the extreme cold regions. A preliminary study consisting of a literature survey in popular data bases and questionnaire survey among users of ppd, were carried out to ascertain what studies have already been conducted in this area and whether a wearability problem really exists among users, respectively. The literature revealed some specific areas where wearability problems exist and some research carried out on methods of testing of ergonomic characteristics of ppd. The questionnaire among ppd users in the cold climate confirmed that the workers do confront many inadequacies in the use of ppd. A case study carried out on ergonomic demands of safety shoes in the cold climate among users, manufacturers and experts revealed a similar trend of demands and priorities in ergonomics of shoes among all three groups. From the findings of the preliminary study it can be concluded that human factors research in ppd and particularly ppd worn on body extremities, viz. safety helmets, shoes and gloves, for use in the cold environment, seem urgent. Some research needs in the development of methods of testing for ppd evaluation are suggested.