bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low Temperature Embrittlement of RPV Support Structure Steel
Authors: Boydon FMD , McElroy RJ , Gage G , Phythian WJ 
Published: March 2009

In recent years concerns have arisen regarding low temperature irradiation damage processes following the observation of an apparent tenfold increase in embrittlement in the HFIR reactor surveillance programme at Oak Ridge compared with accelerated material irradiation's in MTR's. The possible importance of this phenomenon to the integrity of LWR Support Structures was recognised by USNRC and it was formally designated Generic Safety Issue 15. This topic has also become an important UK regulatory issue in the context of the Sizewell PWR. Here the concern was that the high copper material used in the RPV Supports, when taken in light of the HFIR results of that time, highlighted the possibility that irradiation induced copper precipitation could occur at the low temperatures (50–600°C) and peak end-of-life dose of 2mdpa, ~1×1018 n.cm−2 (E&gt;1MeV), encountered in RPV Supports, which contain significant levels (&gt;0.20%) of copper.
This paper describes the results of an experiment set up to establish whether copper precipitation could occur at low temperatures in the Sizewell “B” RPV Support Structure steel. The irradiation was set up to achieve a target dose consistent with the full precipitation of copper, based on modelling data from conventional tests, at the lowest possible damage rate compatible with an irradiation of less than 1 year. The irradiation achieved a high dose of 49.6mdpa, 3.74×1019 n.cm−2 (E&gt;1MeV), at an average temperature of 71°C.
Mechanical properties measured by conventional hardness and Charpy test were performed. The data interpretation was aided by a combination of micro structural and post irradiation annealing experiments. In addition to the Support Structure material, two series of reference alloys with varying copper and nickel content were also irradiated. These alloys have been used in other programmes and offer the ability to cross check the effect of irradiation temperature.
The series of model steels previously studied after irradiation at 288°C in the IAEA CRP-3, under which conditions they exhibited a dependence of hardening on copper and nickel content, showed no clear evidence of copper precipitation under the low temperature irradiation conditions employed. Post irradiation annealing studies demonstrated that the irradiation embrittlement in the A588 support structure steel at low temperatures is due to matrix damage. Although the exact nature of the matrix defect/defects responsible for the embrittlement was not identified, the copper content is believed to be unimportant. There is, therefore, no reason to believe that the relatively high copper specification of A588 support structure steel will be detrimental to the steels toughness after low temperature/high dose irradiation as expected in the Sizewell B support structure.
Application of Micromechanical Models of Ductile Fracture Initiation to Reactor Pressure Vessel Materials
Authors: Chaouadi R , De Meester P , van Walle E , Fabry A , Van de Velde J 
Published: March 2009

The aim of the current study is the application of local micromechanical models to predict crack initiation in ductile materials. Two reactor pressure vessel materials have been selected for this study: JRQ IAEA monitor base metal (A533B C1.1) and Doel-IV weld material. Charpy impact tests have been performed in both un-irradiated and irradiated conditions. In addition to standard tensile tests, notched tensile specimens have been tested.
The upper shelf energy of the weld material remains almost un-affected by irradiation, whereas a decrease of 20% is detected for the base metal. Accordingly, the tensile properties of the weld material do not reveal a clear irradiation effect on the yield and ultimate stresses, this in contrast to the base material flow properties. The tensile tests have been analyzed in terms of micromechanical models. A good correlation is found between the standard tests and the micromechanical models, that are able to predict the ductile damage evolution in these materials. Additional information on the ductility behaviour of these materials is revealed by this micromechanical analysis.
Effects of Helium/DPA Ratio, Alloy Composition and Cold Work on Microstructural Evolution and Hardening of 59Ni-Doped Fe-Cr-Ni Alloys Neutron-Irradiated at 465°C
Authors: Kawanishi H , Hamilton ML , Garner FA 
Published: March 2009

Three ternary austenitic alloys(Fe-15Cr-25Ni, Fe-15Cr-25Ni-0.04P, Fe-15Cr-45Ni in both annealed and cold worked conditions) were irradiated at 465°C to 0.15, 0.28, and 0.42 dpa at above core position in the Fast Flux Test Facility utilizing the Materials Open Test Assembly to study the separate and synergistic effects of He/dpa ratio, phosphorus addition, nickel content and cold work level on microstructural evolution and hardening. The helium/dpa ratio was varied by isotopic doping with 59Ni to enhance the production rate of helium. The helium production rate was evaluated to be 62 appm He/dpa in the 59Ni-doped specimens and 0.26 appm He/dpa in the undoped specimens.
Transmission electron microscopic examinations revealed that alloy composition affected significantly the evolution of microstructure during irradiation. Phosphorus addition prevented the formation of Frank loops through the precipitation of phosphide. Nickel content influenced the nucleation of cavities. Helium production rate influenced the densities of dot-typed clusters in 25Ni alloys and cavities in 45Ni alloys.
Swelling, Mechanical Properties and Structure of Austenitic High-Nickel Alloy Irradiated in a Fast Reactor
Authors: Shamardin VK , Neustroev VS , Povstyanko AV , Bulanova TM , Ostrovsky ZE , Kuznetzov AA , Kursevitch IP , Nikolaev VA 
Published: March 2009

Specimens from fuel assembly wrappers and control rod cases of 0.07C-15Cr-35Ni-3Mo-B-Zr-Y alloy were investigated after irradiation in the BOR-60 and BN-600 reactors up to a maximum damage dose of about 110 dpa at temperatures between 340 to 550°C.
Maximum swelling occurs at 420 to 430°C with 6% at a dose of about 80 dpa and 13.5% at a dose of 108 dpa. The maximum change in strength properties and corresponding decrease of ductility occur at an irradiation temperature of 385°C. With increasing testing temperature the ductility increases from 3–6% up to 22% at 450°C for the material irradiated at 60–80 dpa.
Frank dislocation loops with an average diameter of 25 nm (concentration is 2×1016 cm−3), voids having diameter between 20 to 23 nm (concentration is (6–7)×1014 cm−3) and semicoherent needle-like precipitates with an average length of 21 nm, oriented to several directions, were observed in the alloy structure irradiated to 60 dpa at 430°C.
Analysis of the experimental data was performed and the service life time of the investigated alloy was estimated for use as a material for control rod cases of the BOR-60 reactor.
On the Fundamentals of Radiation Damage in FCC Materials, A Review
Authors: Schüle W 
Published: March 2009

A short historical report is given on the formation of the one-interstitial model (OIM) which was introduced by F. Seitz and H. B. Huntington in the late fifties. In the early sixties J. F. Brinkman and A. Seeger suggested the two-interstitial model (TIM) after many new experimental and theoretical results became available and raised a continous discussion on the validity of the two models.
A few of the many experimental results obtained on radiation damage in fcc metals and alloys over the last thirty-five years are discussed and it is shown that all these results only support the TIM. It could further be shown that the migration activation energies of point defects decrease with increasing high energy particle flux, that dynamic crowdions can change lattice sites 50,000 times before their energy is dissipated to the lattice, that the recombination volume α between self-interstitials and vacancies is one order of magnitude larger than assumed so far etc.. These and many other features of point defects are discussed and the extended version of the TIM, namely the modified two interstitial model (MTIM), is presented.
It is further shown that the rate equations to calculate point defect concentrations built up during irradiation with high energy particles are powerful ways to understand and explain radiation damage. However, the advocates of the OIM in the past used only the steady state solutions of the rate equations which are only mathematical solutions and do not reflect physical reality.
Correlated self-interstitial-vacancy pairs annihilate in recovery stages I and II and correlated crowdion-vacancy pairs annihilate in the broad recovery sub-stage ID in such materials in which crowdions are stable. Crowdions migrate in the tiny sub-recovery stage IE, self-interstitials in recovery stage III, and vacancies in recovery stage IV.
The implications and importance of the application of the MTIM for the development of radiation resistant materials are outlined.
Irradiation Behavior of Weldments of Austenitic Stainless Steel Made by Various Welding Techniques
Authors: Shiba K , Sawai T , Jitsukawa S , Hishinuma A , Pawel JE 
Published: March 2009

An austenitic stainless steel, 316F, irradiated in the High Flux Isotope Reactor to doses of about 8 to 33 dpa at 400° and 500°C was investigated. Electron beam (EB) welding and metal inert gas (MIG) welding techniques were used to make weldment specimens. Weldment specimens were made from their weld metal or weld joint (including heat affected zone) regions of the weldments. Base metal was also studied for comparison. Microstructures of these specimens were observed by TEM.
Tensile tests were carried out at the nominal irradiation temperature in vacuum. Solution annealed 316F showed the large irradiation hardening at 400°C, while the change in yield stress observed at 500°C was not so large. Weldments specimens had the same temperature and dose dependence as the base metal. The differences between EB and MIG after irradiation were small, compared to the differences before irradiation, except for the slight less ductility of MIG weldments. The defect microstructures of weldments were the same as base metal.
Mechanical Performance of Composite Sandwich Beams with Syntactic Foam Cores
Authors: Jize NN , Hiel C , Ishai O 
Published: March 2009

A design concept for composite wind tunnel compressor blades at NASA Ames Research Center was based on a sandwich construction composed of carbon fiber-reinforced polymer (CFRP) skins bonded to a syntactic foam core. The detailed design and analysis of this blade required the input of the elastic and strength properties of the sandwich constituents. Available standards that apply to regular foams and honeycomb cores were found to be partly inadequate for this purpose. An improved testing procedure and its analysis that provided the basic elastic and strength properties are reported in this paper. Tensile, compressive, and shear properties of the foam and skin are identified using beam deflection and failure mode analysis.
Constituent properties derived from beam flexure tests culminate in a general strategy of comparing analytical parameters to results found experimentally. The beam failure modes are found to be either in compressive failure of the skin or in shear failure of the core. This matched the analytical predictions. The deflection of the beam in a three-point flexure test was also found to correlate well with the analytical model.
The study concludes that the correlation between experimental results and the analytical predictions will enable the designer to predict the mechanical behavior and strength of a sandwich beam design. Furthermore, it allows for the experimental analysis of a sandwich beam without having to separate its constituent materials.
Detailed Characterization of a Technical Impracticability Zone Using Drive Point Profiling
Authors: Soloyanis SC , McKenzie MA , Pitkin SE , Ingleton RA 
Published: March 2009

A team of geologists and engineers conducted an investigation in a dense, non-aqueous phase liquid contaminant (DNAPL) source area at Pease Air Force Base (AFB) Installation Restoration Program Site 32. The investigation was designed to (1) demonstrate that vertical drive point profiling using techniques and equipment developed by the Waterloo Centre for Groundwater Research would work at this hydrogeologically complex site and (2) locate solute concentrations indicative of DNAPL.
The original contaminant source at Site 32 was a 1,200-gallon (≅ 4500 L) underground storage tank with an overflow discharge pipe. The tank held waste solvents from aircraft maintenance in Building 113 at the former Pease AFB. The tank was removed in 1988. The overflow discharge pipe and contaminated soil under and along the pipe were removed in 1990. The results of the Site 32 Source Area Remedial Investigation/Feasibility Study indicate that solvent-related contaminants are present in soil and overburden and in bedrock groundwater and that there is a residual DNAPL source resulting in dissolved-phase groundwater contamination. Efforts to locate DNAPL using monitor wells have been unsuccessful. A limited action remedial alternative based on technical impracticability is proposed for this site.
A drive point profiler was used to obtain 40 discrete interval groundwater samples from a total of five locations in nine days of field work. The drive point profiler enabled sampling of fine-grained, low permeability units in which monitor wells would not usually be installed. Samples were analyzed in a mobile laboratory for volatile organic compounds: trichloroethene, 1,2-dichloroethene, and vinyl chloride. The investigation produced useful information about the highly variable distribution of these compounds in the overburden units.
Methods for the Collection of Subsurface Samples During Environmental Site Assessments
Authors: Weinstock EA 
Published: March 2009

With the market for Environmental Site Assessments growing in response to the requirements of lending institutions, the need to collect subsurface samples quickly and inexpensively is greater today than ever before. ASTM, through committee E-50, has developed standardized procedures for the performance of a Pre-Transaction Environmental Screening and for a Phase I Environmental Site Assessment. Standards for the performance of subsurface sample collection during a Phase II Environmental Site Assessment are currently being drafted by committee E-50.
This paper discusses numerous sample collection techniques that have been successfully employed during Phase II Assessments and presents case histories of their application.
The collection of shallow soil samples is described using commercially available hand augers and hand-driven core samplers. These devices are modified with extensions to collect deeper samples from storm drains and leaching pools.
The performance of soil gas surveys are described using both hand-driven sample probes and vehicle-mounted, hydraulically driven vapor probes. Once the soil vapor is collected at the ground surface, a sample of the media is either analyzed on-site using a field-operated detection device or delivered to a laboratory for analysis.
Application and case histories of the Geoprobe(™) sampling system, a form of “direct push” technology, are described. This device uses vehicle-mounted, hydraulically-driven sample probes. The probe can be advanced to depths as great as 100 feet below grade and can retrieve soil, soil gas and groundwater samples.
Use of standard truck-mounted drill rigs are also considered. Collection of soil samples are discussed using standard techniques such as a split-barrel core sampler (ASTM Method D 1586-84, Standard Method for Penetration Test and Split-Barrel Sampling of Soils) and installation of monitoring wells: Applications and case histories of the Hydropunch(™) in-situ groundwater sampler are also described. This device allows for the collection of a groundwater sample during the process of performing a soil boring without the installation of a monitoring well.
The method selected for a given project will vary depending on site-specific criteria such as the depth to groundwater and the subsurface geology. This paper discusses the advantages and disadvantages of each method. It also evaluates the criteria that should be considered in selecting in-situ sampling devices, such as a driven sampling probe, versus a permanent monitoring well.
U.S. Geological Survey Protocol for Measuring Low Levels of Inorganic Constituents, Including Trace Elements, in Surface-Water Samples
Authors: Fitzgerald KK , Miller TL , Horowitz AJ , Demas CR , Rickert DA 
Published: March 2009

The U.S. Geological Survey (USGS) has sponsored a number of studies to evaluate its sampling, processing, and analytical procedures for filtered water samples. The major findings of these studies were that surface-water sampling and processing procedures and equipment used in USGS programs were inadequate to produce contaminant-free trace-element data on a consistent basis. This led to development of a new protocol for collecting, processing, and analyzing filtered water samples for the analysis of trace elements at the 1 microgram-per-liter (ug/L) level using “clean” procedures. The protocol specifies (1) supplies, (2) office and between-site cleaning procedures, (3) samplers, (4) sample splitters, (5) use of disposable capsule filters, (6) quality-assurance measures including use of disposable gloves and shelters for sample processing, and (7) quality-control requirements including blanks, replicates, and split samples.
The USGS is now implementing this protocol for all USGS efforts to produce trace-inorganic data at the microgram-per-liter level on filtered water samples. The protocol will also be used for collecting and processing samples for major ions and nutrients when trace-elements are also being determined.
Decontamination of Field Equipment: An Institutional Status Report
Authors: Bellandi R , Mickam JT , Burrows VC 
Published: March 2009

Advances in hazardous waste remediation have forced the development and refinement of correlative activities such as the decontamination of field equipment. Specific decontamination procedures are routinely included in remediation requirements such as the quality assurance project plan (QAPP). The authors surveyed the decontamination practices of several states and major federal agencies in 1988 before ASTM promulgated D 5088-90, “Decontamination of field equipment used at nonradioactive sites. ” They found a diversity of practices with little consistency of detail or attention.
The authors revisited the practices of several states and the USEPA regions to assess the effect of D 5088-90. Their presumption was that the ASTM standard would make inroads on practices. They found that D 5088-90 has had less than the expected effect because too few practitioners are aware of it.
Application of Nitrogen-Alloyed Martensitic Stainless Steels in the Aviation Industry
Authors: Stein G , Kirschner W , Lueg J 
Published: March 2009

Nitrogen in stainless martensitic steels has a beneficial influence on the mechanical as well as on the chemical properties. However the effect of nitrogen is limited due to the rather low solubility of this element. A special alloy development in combination with a pressurized melting technique lead to distinctly higher nitrogen contents. Stainless martensitic steels containing high nitrogen contents are manufactured by VSG today on an industrial scale using the PESR-process (Pressurized Electroslag Remelting). Depending on special applications these steels are available with different chemical analysis under the trade mark CRONIDUR.
The basic composition of all CRONIDUR-alloys consists of about 15% Chromium, 1% Molybdenum, 0.15 to 0.35% Carbon and 0.20 to 0.40% Nitrogen. The combination of Cr + Mo + N leads to a superior corrosion resistance of these HNS-steels (HNS: High Nitrogen Steels) in comparison to similar carbon based alloys. Focused on applications with a required minimum hardness of 58 HRC, like stainless bearings or screw shafts, the C+N-content is tuned between 0.60 to 0.80% (Brand: CRONIDUR 30). Additions of max. 0.3% Vanadium and 0.1% Niobium qualifies the brand CRONIDUR 20 for enhanced temperature applications like turbine disks or blades.
Prediction and Control of Segregations in CrMoV Steel Ingot for Monoblock HLP Rotor Forgings Using Experimental Results Obtained from 8 Ton Sand Mold Ingots
Authors: Itoh A , Yamada H , Takenouchi T 
Published: March 2009

Remarkable segregation was observed in the modified super clean CrMoV steel forgings for electric power generation applications. Therefore, to make the mechanism clear, effect of such elements as Mn, Ni, Cr and Mo on segregation was studied, using 8 ton sand mold ingots, the solidification time of which corresponds to that of 100 ton ingot.
As a result, we found that factors controlling the segregation are δ-solidification ratio, mean partition coefficient, density difference of molten steels between bulk and segregated liquid at the solidification front and so on. These factors can be calculated from chemical composition of steels.
Then, based on prediction model obtained from the experimental results, chemical composition and shape of ingot were tried to be changed. As for chemical composition, such elements as Mo which is heavy and δ-former were kept low in the specification range. And, as for ingot shape, height to diameter ratio H/D was kept high to shorten the solidification time. The carbon segregation along the axis of ingot was kept relatively low by this ingot design.
The eutectic Nb(C,N) inclusions which give bad effect on the toughness were also investigated. The conditions for the formation of such inclusions were made clear and then predicted and controlled by the calculation from chemical composition.
By this technical development, quality of ingot for HLP rotor forgings was extremely improved.
Predicting Times to Corrosion from Field and Laboratory Chloride Data
Authors: Berke NS , Hicks MC 
Published: March 2009

Corrosion of steel in concrete is one of the major causes of the premature failure of steel reinforced concrete. In marine and deicing salt environments the ingress of chloride is the primary cause for the breakdown of passivity and the onset of severe corrosion. In this paper, we show how to develop effective diffusion coefficients for chloride ingress based on chloride profiles from several marine structures. Predictions of the times to reach chloride levels associated with initiation of severe corrosion are made.
Chloride profiles using effective diffusion coefficients determined in other studies are given for bridge decks and parking structures. There are significant benefits of increased concrete cover and the use of corrosion inhibitors in increasing the time to corrosion. Finally, comparisons of Standard Test Method for Electrical Indication of Concrete's Ability to Resist Chloride Ion Penetration (ASTM C 1202) coulomb values with effective diffusion coefficients, determined from field and laboratory studies, indicate that effective diffusion coefficients for low permeability concretes can be estimated using simple modifications of this test method. Thus, we demonstrate that knowledge of the chloride profile is useful to assess the future performance of existing structures that are not undergoing active corrosion, and in predicting the time to corrosion initiation of new structures.