bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploration of the functional hierarchy of the basal layer of human epidermis at the single‐cell level using parallel clonal microcultures of keratinocytes
Authors: Fortunel Nicolas O. , Cadio Emmanuelle , Vaigot Pierre , Chadli Loubna , Moratille Sandra , Bouet Stéphan , Roméo Paul‐Henri , Martin Michèle T.
Published: February 2010

Please cite this paper as: Exploration of the functional hierarchy of the basal layer of human epidermis at the single‐cell level using parallel clonal microcultures of keratinocytes. Experimental Dermatology 2010.

Abstract:  The basal layer of human epidermis contains both stem cells and keratinocyte progenitors. Because of this cellular heterogeneity, the development of methods suitable for investigations at a clonal level is dramatically needed. Here, we describe a new method that allows multi‐parallel clonal cultures of basal keratinocytes. Immediately after extraction from tissue samples, cells are sorted by flow cytometry based on their high integrin‐α6 expression and plated individually in microculture wells. This automated cell deposition process enables large‐scale characterization of primary clonogenic capacities. The resulting clonal growth profile provided a precise assessment of basal keratinocyte hierarchy, as the size distribution of 14‐day‐old clones ranged from abortive to highly proliferative clones containing 1.7 × 105 keratinocytes (17.4 cell doublings). Importantly, these 14‐day‐old primary clones could be used to generate three‐dimensional reconstructed epidermis with the progeny of a single cell. In long‐term cultures, a fraction of highly proliferative clones could sustain extensive expansion of >100 population doublings over 14 weeks and exhibited long‐term epidermis reconstruction potency, thus fulfilling candidate stem cell functional criteria. In summary, parallel clonal microcultures provide a relevant model for single‐cell studies on interfollicular keratinocytes, which could be also used in other epithelial models, including hair follicle and cornea. The data obtained using this system support the hierarchical model of basal keratinocyte organization in human interfollicular epidermis.
The mouse frizzy (fr) and rat ‘hairless’ (frCR) mutations are natural variants of protease serine S1 family member 8 (Prss8)
Authors: Spacek Damek V. , Perez Amarilis F. , Ferranti Katelynn M. , Wu Lillya K.‐L. , Moy Daniel M. , Magnan David R. , King Thomas R.
Published: February 2010

Please cite this paper as: The mouse frizzy (fr) and rat ‘hairless’ (frCR) mutations are natural variants of protease serine S1 family member 8 (Prss8). Experimental Dermatology 2010; 19: 527–532.

Abstract:  We have previously suggested (based on genetic mapping analysis) that the allelic ‘fuzzy’ and ‘hairless’ mutations in the rat are likely orthologues of the mouse frizzy mutation (fr). Here, we analysed three large intraspecific backcross panels that segregated for mouse fr to restrict this locus to a 0.6‐Mb region that includes fewer than 30 genes. DNA sequencing of one of these candidates known to be expressed in skin, protease serine S1 family member 8 (Prss8), revealed a T to A transversion associated with the fr allele that would result in a valine to aspartate substitution at residue 170 in the gene product. To test whether this missense mutation might be the molecular basis of this frizzy variant, we crossed fr/fr mice with mice that carried a recessive perinatal lethal mutation in Prss8. Hybrid offspring that inherited both fr and the Prss8 null allele displayed abnormal hair and skin, showing that these two mutations are allelic, and suggesting strongly that the T to A mutation in Prss8 is responsible for the mutant frizzy phenotype. Sequence analysis of all Prss8 coding regions in the ‘hairless’ rat identified a 12‐bp deletion in the third exon, indicating that mouse fr and the rat ‘hairless’ mutations are indeed orthologues. However, this analysis failed to detect any alterations to Prss8 coding sequences in the allelic ‘fuzzy’ rat variant.
Analysis of DEFB1 regulatory SNPs in cystic fibrosis patients from North‐Eastern Italy
Authors: Segat L. , Morgutti M. , Athanasakis E. , Trevisiol C. , Amaddeo A. , Poli F. , Crovella S.
Published: February 2010

Cystic fibrosis (CF) transmembrane regulator protein (CFTR) gene is undoubtedly the main genetic factor involved in the modulation of CF phenotype. However, other factors such as human defensins and the genes encoding for these antimicrobial peptides have been hypothesized as possible modifiers influencing airways infection in CF patients, but their role in the pathogenesis of lung disease is still debated. Since DEFB1 gene encoding for human beta‐defensin 1 displays features such as antimicrobial or chemotactic activity playing a role in inflammation, it has been considered as a possible candidate CF modifier gene. We analysed three single nucleotide polymorphisms (SNPs) in the 5′‐untranslated region of the DEFB1 gene (namely g‐52G>A, g‐44C>G and g‐20G>A) in a group of 62 CF patients from North Eastern Italy, and in 130 healthy controls, with the aim of verifying the possible association of these functional SNPs with the pulmonary phenotype of CF patients. DEFB1 SNPs have been genotyped by using Taqman allele‐specific fluorescent probes and a real‐time PCR platform. No significant differences were found for allele, genotype and haplotype frequencies of DEFB1 g‐52G>A, g‐44C>G and g‐20G>A SNPs in CF patients stratified for Pseudomonas aeruginosa infection, as well as in patients with a severe and mild clinical phenotype or in patients stratified for CFTR genotypes. DEFB1 allele, genotype and haplotype frequencies of CF patients globally considered were similar to those of healthy controls. Our findings are discordant with respect to another recent study performed on CF patients coming from Southern Italy, probably due to different ethnicity of the patients.
Association of mannose‐binding lectin polymorphisms and HBV outcome in a South Indian population
Authors: Fletcher G. J. , Gnanamony M. , Samuel P. , Ismail A. M. , Kannangai R. , Daniel D. , Eapen C. E. , Abraham P.
Published: February 2010

Mannose binding lectin (MBL) is an important innate immune system pattern recognition molecule. The MBL gene polymorphisms are reported to play a crucial role in outcome of hepatitis B virus (HBV) infection. In this study, we ascertained the association of MBL genotypes with HBV outcome in a South Indian population. The MBL gene polymorphisms at codons 52, 54 and 57 of exon I, and promoter polymorphisms at −221 were typed by polymerase chain reaction‐sequence specific primer in spontaneously recovered and in chronic HBV group. The allele frequency of codon 52 ‘C’ was significantly higher in chronic HBV group than in the recovered group (98.5% vs. 93.6%; P = 0.003) and codon 52 ‘T’ was significantly higher in recovered group than in the chronic group (6.4% vs. 1.5%; P = 0.003). In multivariate analysis, after adjusting for age, sex and state of origin, codon 52 ‘CC’ and ‘CT’ genotypes were significantly associated with chronicity and recovery respectively [odds ratio (OR), 0.25; 95% confidence interval (CI), 0.08–0.80, P = 0.02] in co‐dominant analyzing models. This was re‐affirmed in analysis performed exclusively on Tamil Nadu subjects (OR, 0.23; 95% CI, 0.06–0.93, P = 0.039). The frequency of low/none haplotype (XY/O) was significantly higher in recovered group than in chronic group (15.6% vs 7.5%) and associated with spontaneous recovery (OR, 2.28; 95% CI, 1.04–4.99, P = 0.035). Our results provide preliminary evidence that inheritance of codon 52 genotypes and XY/O haplotype associated with low MBL level substantially determine the outcome of HBV infection in a sympatrically isolated South Indian population.
Integration of B‐Type Natriuretic Peptide in Heart Failure Outpatient Programs
Authors: Dahlström Ulf , McDonald Ken , Maisel Alan
Published: February 2010

In many European countries, patients with heart failure (HF) are treated according to specific management programs. The key players are the HF cardiologists and the HF nurses, and they are supported by a number of other important players. The objectives of the HF team are to help verify the diagnosis, optimize treatment, and inform and educate the patients and their relatives to achieve beneficial effects in terms of improved survival, less hospitalization, and improved quality of life. The use of natriuretic peptides (NPs) helps the referring physician correctly diagnose and select patients for further investigations. Based on the levels of NPs, it is possible to risk‐stratify patients and offer them individualized, tailored treatment. The present paper discusses and exemplifies how NP assessment may be integrated into an HF outpatient program. Our conclusion is that NP values will continue to be important and necessary tools in the routine management of patients with HF. Congest Heart Fail. 2008;14(4 suppl 1):9–11. ©2008 Le Jacq
Usefulness of Serial Assessment of Natriuretic Peptides in the Emergency Department for Patients With Acute Decompensated Heart Failure
Authors: DiSomma Salvatore , Magrini Laura , Pittoni Valerio , Marino Rossella , Peacock W. Frank , Maisel Alan
Published: February 2010

The value of natriuretic peptides, both B‐type natriuretic peptide (BNP) and N‐terminal prohormone brain natriuretic peptide (NTproBNP), for determining diagnosis, severity, and prognosis of emergency department (ED) patients with acute decompensated heart failure (ADHF) has been well documented. Emerging data support the hypothesis that repeated natriuretic peptide determinations in the acute phase of ADHF may assist in confirming the diagnosis, monitoring drug therapy, and evaluating the adequacy of patient stabilization. Data from the authors' group demonstrate that in patients admitted to the ED for acute dyspnea, serial NTproBNP measurement at admission and 4, 12, and 24 hours later was useful in confirming the diagnosis of ADHF compared with patients with chronic obstructive pulmonary disease. Moreover, in the same patients receiving intensive intravenous diuretic therapy, there was a progressive reduction of NTproBNP blood levels from hospitalization to discharge (P<.001), accompanied by clinical improvement and stabilization of heart failure. More recently, the authors also demonstrated that in ADHF patients improving with diuretics, a progressive reduction in BNP levels was observed, starting 24 hours after ED admission and continuing until discharge. Comparing BNP and NTproBNP, there was a significant correlation between NTproBNP and BNP levels but not between NTproBNP's and BNP's percent variation compared with baseline. In ADHF, serial ED measurements of BNP are useful for monitoring the effects of treatment. A reduction in BNP from admission to discharge is indicative of clinical improvement. Congest Heart Fail. 2008;14(4 suppl 1):21–24. ©2008 Le Jacq
Natriuretic Peptides in Acute Coronary Syndromes: Prognostic Value and Clinical Implications
Authors: Farmakis Dimitrios , Filippatos Gerasimos , Tubaro Marco , Peacock W. Frank , DiSomma Salvatore , Mueller Christian , Kremastinos Dimitrios Th. , Maisel Alan S.
Published: February 2010

Levels of natriuretic peptides, including B‐type natriuretic peptide and N‐terminal prohormone brain natriuretic peptide, are strong independent predictors of prognosis in acute coronary syndrome (ACS). They are associated with short‐and long‐term mortality and with the risk of new‐onset heart failure, above and beyond the conventional risk factors. Myocardial ischemia and ventricular wall stress are triggers for the release of natriuretic peptides, and although the latter are associated with the severity of the underlying coronary artery disease, they fail to predict recurrent nonfatal ACS. In conclusion, natriuretic peptide values may improve risk stratification in ACS when used in addition to troponin levels and other prognostic markers, but more data are needed to define their role in ACS therapy. Congest Heart Fail. 2008;14(4 suppl 1):25–29. ©2008 Le Jacq
Remote Monitoring for Atrial Fibrillation
Authors: Engel Gregory , Mead R. Hardwin
Published: February 2010

Remote monitoring for atrial fibrillation (AF) provides invaluable tools for diagnosis and management. Recent advances in monitoring technology have improved the ability to care for patients with AF. Wireless remote monitoring of implanted devices is revolutionizing the way health care professionals care for this subgroup of patients. Early identification and treatment of paroxysmal AF episodes has the potential to reduce the progression to persistent or permanent AF. Prompt initiation of anticoagulant therapy can reduce the rate of strokes. More thorough and real‐time remote monitoring can help evaluate to improve the efficacy of rate control, antiarrhythmic drug therapy, and catheter or surgical ablation procedures. In addition to improvements in clinical care, early detection and treatment of AF could reduce health care costs associated with AF. Congest Heart Fail. 2008;14:14–18. ©2008 Le Jacq
Practical Considerations for Remote Monitoring
Authors: Epstein Laurence M. , Shea Julie B.
Published: February 2010

The ability to remotely monitor important physiologic parameters will dramatically change how we care for patients. We are on the threshold of this era with currently available implantable cardiac devices. Current devices provide a plethora of important arrhythmia‐and heart failure‐related information. Dealing with this “flood” of information and a new “work flow” can be a challenge. Careful planning can reduce the stress and improve patient care. Electrophysiologists and heart failure practitioners are on the cutting edge of this revolution in health care and therefore are required to deal with the challenges this technology brings. However, they also have the opportunity to shape the future of heart failure management. Congest Heart Fail. 2008;14:25–28. ©2008 Le Jacq
Male-specific induction of CYP3A2 in rats by zolmitriptan
Authors: Yu Lushan , Lu Sijie , Zhao Naping , Ni Shaoqing , Yao Tongwei , Zeng Su
Published: February 2010

We report here a novel observation that zolmitriptan induced CYP3A2 in male but not female rats. As part of our research programme to evaluate sex differences in the response to zolmitriptan, we studied the effects of zolmitriptan on CYP3A activity, protein and gene expression in male and female rats. Zolmitriptan was found to induce CYP3A activity, measured as testosterone and diazepam metabolism in-vitro, as well as midazolam pharmacokinetics in-vivo, in male but not female rats. The sex difference in response to zolmitriptan was further evaluated by analysis of CYP3A1/2 mRNA levels using real-time PCR, and CYP3A1/2 protein levels using immunoblotting. Zolmitriptan preferentially induced CYP3A2 in male but not female rats. No obvious effects on CYP3A1 were observed at any dose in either sex. Thus, we concluded that the observed sex-dependent induction of CYP3A by zolmitriptan was largely due to induction of CYP3A2 in male rats.
STP Balance of Plant Model Update Experience and Results
Authors: Kee Ernie , Yilmaz Fatma , Wakefield Don , Epstein Steve
Published: February 2010

The South Texas Project (STP) balance of plant (BOP) model for production losses has been converted from an Excel-based software application that uses minimal cutsets from a single large fault tree, to a set of small fault trees used within a risk analysis tool, Riskman® [8]. The Riskman® application provides estimates of interest to plant investors and owners such as potential production losses and plant profitability, as well as production reliability and quality (loss frequency, type of loss, loss duration and standard economic risk metrics). The BOP models and methodologies developed are applicable to both fault-tree linking and event-tree linking styles of risk analysis. The STP BOP model is developed to support configuration risk management in two categories: 1) trip risk and concomitant core damage frequency; and 2) non-trip production risk. The primary purpose for the conversion work is to make the STP BOP model framework and application platform consistent with the STP probabilistic risk assessment model. In the course of the conversion, improvements to the Riskman® software have been implemented and techniques to more efficiently produce BOP modeling (fault tree) improvements were developed. Better methods to accurately calculate initiating event frequencies are studied. New data types added to support BOP modeling are described.
Analysis for Digital Pulse Waveform Based on Cd (Zn) Te Detector
Authors: Di Yu-ming , Li Zhan-liang , Fang Guo-ming , Han Feng , Qiu Xiao-lin , Xu Peng , Wu Yuelei
Published: February 2010

The waveform of current pulse in Cd(Zn)Te detector and that of output pulse of preamplifier are analyzed in detail. The reasons of pulses pile-up are presented. By means of digital signal processing technique, an identification method of pulse pile-up type is built. The results make it possible to use of pulses of slight leading-edge and general lagging-edge pile-ups.
Analysis of the Quench-14 Bundle Test With M5® Cladding
Authors: Birchley Jonathan C. , Jaeckel Bernd , Haste Timothy J. , Steinbrueck Martin , Stuckert Juri
Published: February 2010

The QUENCH experimental programme at Forschungszentrum Karlsruhe (FZK) investigates phenomena associated with reflood of a degrading core under postulated severe accident conditions, but where the geometry is still mainly rod-like and degradation is still at an early phase. The QUENCH test bundle is electrically heated and consists of 21 fuel rod simulators with a total length of approximately 2.5 m. The cladding and grid spacers are identical to those used in Pressurized Water Reactors (PWR) whereas the fuel is represented by ZrO2 pellets. Experiment QUENCH-14 was successfully performed at FZK in July 2008 and is the first in this programme where Zr-Nb alloy M5® is used as the fuel rod simulator cladding. QUENCH-14 was otherwise essentially the same as experiment QUENCH-06, which was the subject of the CSNI ISP-45 exercise. It is also the first of three experiments in the QUENCH-ACM series, recently launched to examine the effect of advanced cladding materials on oxidation and quenching under otherwise similar conditions. Pre- and post-test analyses were performed at PSI using a local version of SCDAP/RELAP5 and MELCOR 1.8.6, using input models which had already been benchmarked against QUENCH-06 data. Preliminary pre-test calculations with both codes and alternative correlations for the oxidation kinetics indicated that the planned test protocol would achieve the desired objective of exhibiting whatever effects might arise from the change in cladding-material in the course of a transient similar to QUENCH-06. Several correlations were implemented in the models, namely Cathcart-Pawel, Urbanic-Heidrick, Leistikow-Schanz and Prater-Courtright for Zircaloy-4 (Zry-4), and additionally a new candidate correlation for M5® based on recent separate-effects tests performed at FZK on M5® cladding samples. Analyses of the QUENCH-14 data demonstrate strengths and limitations of the various models. Some tentative recommendations are made concerning choice of correlation and effect of cladding material.
Simulation of Vessel-With-Melt Deformation by SOCRAT/HEFEST Code
Authors: Filippov Alexander , Drobyshevsky Nikolay , Kisselev Arkady , Strizhov Valery
Published: February 2010

Finite element structural code HEFEST-M is advanced together with results of simulations. HEFEST-M possibilities include large nonlinear deformation, contact interaction of the deformed domains, elastic-plastic and high-temperature creep models. The creep model coefficients were defined for the two kinds of reactor vessel steel: SA533B1 (PWR) and 15×2HMVA (VVER). Failure criteria are implemented in the code. Some examples of test calculations are presented in the paper. The results of simulation of the VVER-1000 vessel containing core melt are presented and discussed.
Natural Crack Growth in BWR Shroud Support Dissimilar Metal Weld Joints
Authors: Hankinson S. F. , Hayashi T. , Ng C. K. , Swamy S. A.
Published: February 2010

The Boiling Water Reactor (BWR) shroud support dissimilar metal (DM) joints, which are made of Alloy182 nickel based alloy weld material, are susceptible to Intergranular Stress Corrosion Cracking (IGSCC). IGSCC of these weld joints is an industry wide issue that is receiving constant attention from both power plant operators and regulatory agencies. Crack growth due to IGSCC in the shroud support DM weld joints is typically evaluated based on conventional idealized crack shape instead of natural crack shape dictated by the crack tip stress intensity factors calculated along the entire crack front. Due to the complexity in the geometry and stress field at these weld joints, the use of natural crack shape as the crack propagates would provide a more realistic assessment of crack growth and structural integrity of the shroud support dissimilar metal weld joints. This paper describes the simulation of natural crack growth due to IGSCC in the shroud support DM weld joints through the use of advanced finite element fracture mechanics techniques. Typical normal operating stresses including welding residual stresses at these weld joints were considered in the IGSCC crack growth simulation. A comparison of the crack growth results between the use of idealized and natural crack shape was made to assess the impact on the structural integrity of the BWR shroud support DM weld joints.
Analysis and Characterization of Sequences in Atucha II PHWR
Authors: Zanocco Pablo , Gonzalez Jose´ , Gime´nez Marcelo
Published: February 2010

In this work, a case of loss of heat removal, caused by a loss of electrical supply, is analyzed for Atucha II PHWR. This reactor is similar to a PWR reactor in many aspects, but differs because it has, inside the pressure vessel, vertical coolant channels inside a moderator tank, which is at primary system pressure but a lower temperature. During the studied event, moderator temperature rises, heated by primary system (acting as a heat sink), until the temperatures are equalized. Given that primary and moderator systems are interconnected, the expansion of the moderator produces a rise in the level in pressurizer. The main aspects of the plant dynamic in the presented case are shown and analyzed. The normal strategy of the plant to cope with this initiating event is also discussed: the systems involved, operational modes and trigger signals are described. Then, three possible sequences are studied: heat removal by steam generators or moderator heat exchangers, and black out (no heat removal). The safety functions required to cope with this initiating event are also determined, as long as the associated safety and auxiliary systems. Representative variables of selected sequences are shown, in order to go further in understanding of the plant behavior. The different final stages are identified. The minimum capability of each system, necessary to achieve a plant safe condition, is also established. It was found that in this particular event, their requirements are less than the ones specified in the design basis. Also the influence of moderator system thermal inertia on transients is determined as a distinctive characteristics of this reactor.
Safety Aspects of a PWR With an Inventive TRISO Fuel Particle Composition
Authors: Hussain Anwar , Cao Xinrong
Published: February 2010

In this research paper a safety analysis has been carried out for the conceptual design of a compact sized PWR core that utilizes tristructural-isotropic (TRISO) fuel particle with an inventive composition. The use of TRISO fuel in PWR technology improves integrity of the design due to its fission fragments retention ability as this fuel provides first retention barrier within fuel itself against the release fission fragments. Hence addition of one more reliable barrier in well established PWR technology makes this design concept safer and environment friendly. The suggested TRISO fuel particle composition has a small amount of Pu-240 with 2.0 w/o in the place of U-238 which acts as reactivity suppressor. The amount of excess reactivity has been reduced significantly by using a small amount of Pu-240 in TRISO fuel which in turns reduces the number of Burnable Poison (BP) and control rods required for reactivity control and completely eliminates the requirement of soluble boron system. The suggested design operates at much lower temperature and pressure than a standard PWR power reactor because of its specific use (i.e. heating, desalination and limited power production) and the presence of TRISO fuel ensures retention of fission fragments at elevated temperatures. All reactivity coefficients were found negative for the designed core and shutdown margin has also been increased with the suggested TRISO fuel composition.
Investigation of Chemical Effects on Emergency Core Cooling Filtration Head Loss After Loss of Coolant Accident
Authors: Park Jong Woon , Park Byung Gi , Kim Chang Hyun
Published: February 2010

Integrated tests of head loss through an emergency core cooling filter screen are conducted, simulating reactor building environmental conditions for thirty days after a loss of coolant accident. A test apparatus with five individual loops each of whose chamber is established to test chemical product formation and measure the head loss through a sample filter. The screen area at each chamber is 78.54cm2 and reactor building materials can be scaled down according to specific plant condition. A series of tests have been performed to investigate the effects of reactor building spray, existence of calcium-silicate with tri-sodium phosphate (TSP), and composition of materials. The results showed that head loss across the chemical bed with even a small amount of calcium-silicate insulation instantaneously increased as soon as TSP was added to the test solution. Also, the head loss across the filter screen is strongly affected by spray duration and the head loss increase is rapid at the early stage, because of high dissolution and precipitation of aluminum and zinc. After passivation of aluminum and zinc by corrosion, the head loss increase is much slowed down and is mainly induced by materials such as calcium, silicon, and magnesium leached from NUKON™ and concrete. Furthermore, it is newly found that the spay buffer agent, tri-sodium phosphate, to form protective coating on the aluminum surface and reduce aluminum leaching is not effective for a large amount of aluminum and a long spray.
Acoustic Loading of Steam Dryers: Load Attributes and Structural Response
Authors: Shehane Michael , Moore Eric M. , Ruggles Arthur E.
Published: February 2010

Acoustic waves in the steam supply of some Boiling Water Reactors have caused fatigue cracking of steam dryers. The physics of acoustic source terms in the steam supply are reviewed and attributes of the acoustic loading are illustrated. Novel signal interrogation techniques are developed to characterize variability over time in load amplitude as a function of load frequency. Time varying attributes of the dynamic loading are related to component dynamic stress prediction methods to enable component endurance predictions.
Core Melt Solidification Characteristics in RPV Lower Head: Experimental Results From LIVE-Tests
Authors: Gaus-Liu Xiaoyang , Miassoedov Alexei , Cron Thomas , Foit Jerzy , Wenz Thomas , Schmidt-Stiefel Silke
Published: February 2010

Core melt solidification phenomena during external reactor vessel cooling is investigated in LIVE tests with different external cooling conditions and melt pouring positions. A non-eutectic simulant melt (80-20 mole% KNO3-NaNO3) is used in the LIVE tests. It is found out that when the vessel is cooled with water at the beginning of the melt pouring, the cooling is more effective than in the case of delayed water cooling condition, in which the vessel is first cooled with air and then flooded by water. The initial water cooling leads to a faster growth of crust layer, lower crust thermal conductivity and thinner crust layer than those under the delayed water cooling condition. The initial water cooling leads also to higher heat flux through the vessel wall during the steady state and shorter crust growth period in comparison with the delayed water cooling condition. The solidification of the melt is probably under supercooling condition. The pouring position near the vessel wall results in considerable asymmetric heat flux distribution at one latitude. The heat flux at the position of melt pouring is higher than the one at other locations.
Approach for the Analysis of a Shutdown Scenario in the Framework of the Validation of Severe Accident Management Guidelines in Belgium
Authors: Cipollaro Antonio , Sallus Laurent
Published: February 2010

During last four years, in the framework of the periodic safety review of the Belgian Nuclear Power Plants, the Severe Accident Management Guidelines implemented in Belgium have been involved in a series of detailed validation exercises as suggested by the Westinghouse Owner Group SAMG Scenario Templates. The purpose of this task is essentially to evaluate the severe accident management capabilities of the units and to ensure that personnel in the utility’s emergency response organization (crisis team and eventually the control room staff for certain type of accidents) are trained with the use of the above mentioned guidelines. The supporting calculations to the validation exercises have been performed by Tractebel Engineering by means of the MELCOR 1.8.5 code, which is developed under the sponsorship of the United States Nuclear Regulatory Commission (USNRC). Most of the implemented scenarios and related validation exercises account for full power operating states and are based on previous PSA studies. These included Station Black-Out accidents (SBO), Small Break Loss of Coolant Accidents (SBLOCA), Large Break Loss of Coolant Accidents (LBLOCA), and Interface System Loss of Coolant Accidents (ISLOCA), possibly including additional losses of available emergency safeguards features (ECCS, containment sprays, fan coolers, chemical and volumetric control system). In order to cover the entire spectrum of possible scenarios, it has been judged necessary to consider also a type of accident not originated at nominal power but initiated while the plant is in shutdown conditions. The specific Plant Operating State characterizing this scenario has been defined by a mid-loop operation with the reactor pressure vessel head still in place, and including the opening of the pressurizer manhole, the installation of the nozzle dams in all steam generators, the isolation of the reactor building, and the operation of the Residual Heat Removal system. The initiating event of this accident is the loss of the Residual Heat Removal system one day after the normal reactor shutdown. A point demanding a special attention is the fact the entry criterion to redirect towards the opening of the SAMG (based on core exit temperature measurement in full power states) does not straightforward apply in this case and an alternative criterion is necessary. In particular this paper presents the approach and results obtained accounting for the proposed criterion based on the launch of the internal emergency plan and on the timing for the crisis team to be operational and take the decision.
Nonlinear Analyses for Thermal Cracking in the Design of Concrete Structures
Authors: James Randy J. , Liu Ai-Shen
Published: February 2010

A Design by Analysis procedure has been developed to incorporate the results of thermal cracking analyses into the linear based design methods for reinforced concrete containment structures. Current practice employs linear based analyses and accounts for stress reduction due to thermal induced cracking on a section by section basis. Under thermal loading, in addition to a reduction of the section forces and moments for cracked sections, concrete cracking also reduces the structural stiffness and thus the constraint against thermal expansion or contraction for the whole structure, which in turn reduces the thermal induced stresses as compared to a linear (un-cracked) analysis. The design by analysis approach employs nonlinear thermal cracking analyses using detailed modeling of the complete structure. By comparing these stress distributions with those from a linear analysis of the same model, stress reduction factors can be developed for critical sections that also include global stress redistribution. These stress reduction factors can then be used to correct linear based thermal stresses in the design basis calculation for all load combinations that include thermal loads.
Stress Classification Plane and Its Application in Finite Element Analysis
Authors: Yang Jianfeng
Published: February 2010

The stresses within pressure vessels and internals, etc. are categorized into membrane, bending, and peak stresses in the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code, as well as many other design codes of different countries. The total stress results calculated from a finite element analysis, which is the most commonly utilized tool in the component design, have to be classified into these categories to be compared to the design code criteria. The stress classification line (SCL) method has been developed to linearize the stresses along a line cutting through the thickness of the component. However, the SCL method tends to overestimate or underestimate the linearized stresses if the stress distribution of the cross-section is not axisymmetric. Since the design code criteria are given over a cross-section, this article proposes a stress classification plane (SCP) method in stress linearization. An SCP is defined as a cross-section that cuts through a solid 3-D finite element model. The element nodes do not need to lie on the SCP. The stresses are linearized over the entire cross-section that defines the SCP. Therefore, the linearized stresses obtained using this method are consistent with the design code definitions. The SCP approach provides an accurate and convenient tool when comparing the finite element results to the Code criteria during the component design and analysis process. As an example, the applications of the SCP method using ANSYS® are also given in this article.
Analytical Investigation of Deaerator Steam Inlet Nozzle Corrosion Allowance in a CANDU Station
Authors: Keshavarz Ali , Ali Andrew K. , Lall Randy K.
Published: February 2010

Flow-accelerated corrosion (FAC) is a phenomenon that results in metal loss from piping, vessels and equipment made of carbon steel. This metal loss can lead to stress to occur at the steam inlet nozzle side, where it is located at the side of the deaerator. This paper presents a method to find the thickness critical of the steam inlet nozzle. A Finite Element (FE) model of the pressure vessel head was created to perform a stress analysis using NX Nastran 5.0. By applying materials properties, loads and constraints to the model, the results obtained are required to satisfy the following criterion: vonMises≥SySy=YieldStrength The results obtained from the stress analysis were analyzed to obtain a corrosion allowance and it was compared to the recommended value from a normal deaerator design, which is roughly 0.25 inches. From the FE model, and by continuously reducing the thickness of the nozzle, it was determined that the corrosion allowance is 0.229 inches, and that the percentage error was 8.4%.
The Development of Impact Analysis Methodology for CEDM Missile of APR1400
Authors: Kang Tae Kyo , Park Jin Seok , Kim Hyun Min , Kim In Yong
Published: February 2010

The paper deals with the impact analysis methodology for control element drive mechanism (CEDM) missile of advanced Power Reactor 1400 (APR1400). The methodology includes the development of jet expansion models to develop the missile velocity as well as the missile impact analysis itself and the application of Fauske model to obtain jet velocity in two-phase critical flow. The CEDM missile is produced by jet thrust when the reactor vessel nozzle breaks during Safe-Shutdown-Earthquake (SSE) and/or dynamic events of accidental condition. Jet velocity from the nozzle exit should be determined before the determination of missile velocity. The jet provides the kinetic energy pushing up a missile. In previously operating plants, the jet was assumed to occur in a single-phase flow so that it may result in overly conservative velocities to design missile barriers. In order to determine the jet velocity, the jet is characterized in two-phase critical flow, and Fauske slip equilibrium model is applied to the jet. Furthermore it is important to determine the missile velocity from the jet impingement to be applied in the missile impact analysis as an input loading. Various jet expansion models are suggested in calculating the missile velocities herein, where consideration is given to various jet expansion and jet impingement on an object. With the missile velocities using the models, the nonlinear CEDM missile impact analysis is performed to investigate structural responses of the missile shield with the Integrated Head Assembly (IHA) of APR1400. Because the missile shield is tied to the inside of IHA with a complicate manner, it is important to analyze and evaluate the missile impact behaviors to demonstrate the structural adequacy of the missile shield as well as IHA. Comparisons of the analysis results are influential to the design evaluation in case of using missile velocities by different flow models, wherein the jet is assumed to occur in single-phase flow or two-phase flow.
A Study of Some Key Parameters Used in the Environmental Fatigue Evaluation of a Hot Leg Surge Nozzle
Authors: Wiley Tim F. , Pournaras Tim J. , Kupper Chris T. , Gray Mark A. , Swamy Seth A.
Published: February 2010

When considering environmentally assisted fatigue (EAF) in the fatigue evaluation of nuclear power plant components, some assumptions made pertaining to plant operation in the design basis fatigue analyses have to be re-evaluated to accommodate potential increase in fatigue usage factors resulting from environmental effects. The surge line was identified in NUREG/CR-6260 [1] to be a representative component for the evaluation of EAF for Pressurized Water Reactor (PWR) plants. For some PWR plants, the hot leg surge nozzle is one of the components evaluated for environmentally assisted fatigue. The hot leg surge nozzle was chosen for this study because the results of the fatigue evaluation are highly dependent on several key parameters, such as maximum temperature difference between the pressurizer and hot leg piping during heatups and cooldowns, the amount of temperature sensor data available along the surge line, availability of thermal event cycle counting, and the frequency and timing of reactor coolant pump starts and stops during heatups and cooldowns. This paper assesses the impacts of the assumptions made in these key parameters on the environmental fatigue evaluation results for a typical hot leg surge nozzle.
iMASS: Evolved NRF Simulations for More Accurate Detection of Nuclear Threats
Authors: Perry John , Xiao Shanjie , Jevremovic Tatjana
Published: February 2010

The intelligent Model-Assisted Sensing System (iMASS) combines computer simulated nuclear resonance fluorescence (NRF), real-time Monte Carlo analysis, and signal data processing for the detection of nuclear materials hidden in cargo containers. There are on average nine million cargo containers entering the US every year. Fast and robust scanning for nuclear materials and explosives is of the outmost importance for a country’s security and safety. This paper presents the Geant4 platform development for direct application in nuclear material detections, including: an improved module to simulate the bremsstrahlung spectra, a model for NRF simulations addressing the Compton continuum background that would be found during an actual scan, and the improvements in output data interpretation. The dynamic flexibility of Geant4 and the ability to be sped up with field programmable gate array (FPGA) and parallelization is also described.
Gas Phase Oxidation of Elemental Iodine in Containment Conditions
Authors: Ka¨rkela¨ Teemu , Holm Joachim , Auvinen Ari , Ekberg Christian , Gla¨nneskog Henrik , Tapper Unto , Zilliacus Riitta
Published: February 2010

The aim of the study was to verify the possible formation of iodine aerosol when gaseous iodine is exposed to radiation. The effect of oxygen, ozone and iodine concentration as well as that of radiation intensity on IOX aerosol formation was determined. Experimental evidence on kinetics of particle formation, growth and transport was gained. Experiments were carried out using EXSI facility at VTT. Gaseous iodine was produced from I2-KI-water solution and carried into the facility with N2-O2 mixture. Oxygen concentration was varied between 2–50 %-vol. Due to the production technique flow contained always some humidity. UVC lamps were used as source of ionizing radiation. Ozone concentration was also varied with an ozonator. The reactions took place in a flow furnace heated to 120°C. Reaction and aerosol kinetics were studied by varying the residence time between about 2–7 seconds. The formed particles were collected on filters, after which gaseous iodine was trapped in NaOH-water solution. The amount of iodine in filters and in trapping bottles was analysed with ICP-MS. Particle concentration and size distribution were measured online using aerosol instrumentation. Ozone concentration was measured online with FTIR. The morphology as well as the elemental composition of the particles were analysed with SEM-EDX. The conversion of gaseous iodine to aerosol particles was rapid and almost complete even with low ozone concentration. The fraction of gaseous iodine increased though with decreasing residence time. Diameter of the formed primary particles was approximately 10 nm. Particles grew by agglomeration and by surface reaction. Agglomerate size distribution was log-normal with NMD varying between 60–120 nm. Size of the agglomerates increased and number concentration decreased with increasing residence time. Agglomerate size also increased with iodine concentration. Presence of ozone promoted retention of iodine in the facility probably by surface reaction. Some iodine deposited on surfaces evaporated later and formed particles in the gas stream. According to SEM-EDX analysis, particles deposited on carbon foil contained iodine and oxygen. However, the exact speciation is not known. Particles deposited on copper grids had probably reacted to copper iodide.
Effects of Ruthenium Release in Oxidizing Conditions on a BWR Source Term
Authors: Suopaja¨rvi Atso , Ka¨rkela¨ Teemu , Auvinen Ari , Lindholm Ilona
Published: February 2010

The release of ruthenium in oxygen-rich conditions from the reactor core during a severe accident may lead to formation of significantly more volatile ruthenium oxides than produced in steam atmosphere. The effect of volatile ruthenium release in a case a reference BWR nuclear plant was studied to get rough-estimates of the effects on the spreading of airborne ruthenium inside the containment and reactor building and the fission product source term. The selected accident scenario starting during shutdown conditions with pressure vessel upper head opened was a LOCA with a break in the bottom of the RPV. The results suggest that there is a remarkable amount of airborne Ru in the containment atmosphere, unlike with the standard MELCOR Ru release model which predicts no airborne Ru at all in the selected case. The total release of ruthenium from the core can be 5000 times the release predicted by the standard model. Based on the performed plant scoping studies it seems reasonable to take the release of volatile ruthenium oxides into account when assessing source terms for plants during shutdown states.
DOE Reworks Student Initiative to Prepare Energy Researchers
Authors: Mervis Jeffrey
Published: February 2010

The U.S. Department of Energy has downsized a proposal to train more scientists and engineers to work in a low-carbon economy. The president's 2011 budget request contains a slimmed-down RE-ENERGYSE, with a price tag of $50 million—$35 million for higher education and $15 million for technical training and precollege outreach.
Cancer's Circulation Problem
Authors: Kaiser Jocelyn
Published: February 2010

Researchers are counting and examining the rare cells shed by a primary tumor that circulate in the blood, but will these studies help patients?
Fatal
Citrobacter farmeri
Meningitis in a Patient with Nasopharyngeal Cancer
Authors: Tan Che-Kim , Lai Chih-Cheng , Lin Sheng-Hsiang , Liao Chun-Hsing , Huang Yu-Tsung , Hsueh Po-Ren
Published: February 2010

We describe the case of an adult male with nasopharyngeal carcinoma who had meningitis caused by
Citrobacter farmeri
. The isolate was confirmed as
C. farmeri
by two commercial identification systems and 16S rRNA gene analysis. The patient developed multiorgan failure and died despite antibiotic treatment with
in vitro
active agents (ceftriaxone and meropenem).
Staphylococcus aureus
Antimicrobial Susceptibility of Abscess Samples from Adults and Children from the Kaleida Health System in Western New York State, 2003 to 2006
Authors: Hsiao Chiu-Bin , Dryja Diane , Abbatessa Laurie , Patel Pravin H.
Published: February 2010

Staphylococcus aureus
is the most common etiologic agent of skin abscesses. The regional rate of methicillin-resistant
S. aureus
(MRSA) abscesses may reflect the prevalence of local community-acquired MRSA (CAMRSA). A retrospective study was conducted to compare the antimicrobial susceptibility patterns of
S. aureus
isolates recovered from abscesses from 2003 to 2006 from patients at hospitals of the Kaleida Health System in western New York.
S. aureus
susceptibility information was obtained from a Vitek Legacy system, and the location and source of each isolate were identified. EpiInfo software was used to analyze the antimicrobial susceptibilities of all isolates and the trends in the rates of MRSA. A total of 2,848
S. aureus
abscesses were identified by the Kaleida Health Clinical Microbiology Laboratory. Of those, 978
S. aureus
abscess events occurred in four hospitals, including three adult facilities (547 episodes with 62 cases of bacteremia) and one children's facility (431 episodes with 2 cases of bacteremia). The MRSA rates in adults increased from 56% (2003) to 71% (2006), and that in children increased from 26% (2003) to 64% (2006). Of the MRSA isolates in the children's samples, more than 92% were susceptible to clindamycin. Of the MRSA isolates in the adult samples, 50% were susceptible to clindamycin in 2003 and 2004, whereas greater than 75% were susceptible in 2005 and 2006. The increased rates of MRSA abscesses with susceptibility to clindamycin may reflect the high prevalence level of CAMRSA in the western New York community. The variations in
S. aureus
susceptibilities could serve as an indicator of the changing resistance patterns within a broad urban community.
Comparison of the BD GeneOhm Methicillin-Resistant
Staphylococcus aureus
(MRSA) PCR Assay to Culture by Use of BBL CHROMagar MRSA for Detection of MRSA in Nasal Surveillance Cultures from Intensive Care Unit Patients
Authors: Snyder James W. , Munier Gina K. , Johnson Charles L.
Published: February 2010

This study compared the BD GeneOhm methicillin-resistant
Staphylococcus aureus
(MRSA) real-time PCR assay to culture by the use of BBL CHROMagar MRSA for the detection of MRSA in 627 nasal surveillance specimens collected from intensive care unit (ICU) patients. The PCR assay had a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 96.7%, 70.3%, and 100%, respectively. Nine of 19 false-positive PCR specimens grew methicillin-susceptible
S. aureus
(MSSA) from broth enrichment culture, of which two demonstrated evidence of
mec
A
gene dropout. Compared to culture by the use of BBL CHROMagar MRSA, the BD GeneOhm MRSA PCR assay demonstrated sensitivity and specificity above 95% for the detection of MRSA nasal colonization and provided shorter turnaround time in generating positive and negative final results.