bluuebunny/crossref_metadata_2025 huggingface dataset:
QTL and QTL × Environment Effects on Agronomic and Nitrogen Acquisition Traits in Rice
Authors: Senthilvel Senapathy , Vinod Kunnummal Kurungara , Malarvizhi Palaniappan , Maheswaran Marappa
Published: September 2008

Agricultural environments deteriorate due to excess nitrogen application. Breeding for low nitrogen responsive genotypes can reduce soil nitrogen input. Rice genotypes respond variably to soil available nitrogen. The present study attempted quantification of genotype × nitrogen level interaction and mapping of quantitative trait loci (QTLs) associated with nitrogen use efficiency (NUE) and other associated agronomic traits. Twelve parameters were observed across a set of 82 double haploid (DH) lines derived from IR64/Azucena. Three nitrogen regimes namely, native (0 kg/ha; no nitrogen applied), optimum (100 kg/ha) and high (200 kg/ha) replicated thrice were the environments. The parents and DH lines were significantly varying for all traits under different nitrogen regimes. All traits except plant height recorded significant genotype × environment interaction. Individual plant yield was positively correlated with nitrogen use efficiency and nitrogen uptake. Sixteen QTLs were detected by composite interval mapping. Eleven QTLs showed significant QTL × environment interactions. On chromosome 3, seven QTLs were detected associated with nitrogen use, plant yield and associated traits. A QTL region between markers RZ678, RZ574 and RZ284 was associated with nitrogen use and yield. This chromosomal region was enriched with expressed gene sequences of known key nitrogen assimilation genes.
Global Identification of Significantly Expressed Genes in Developing Endosperm of Rice by Expression Sequence Tags and cDNA Array Approaches
Authors: Tu Qichao , Dong Haitao , Yao Haigen , Fang Yongqi , Dai Cheng'en , Luo Hongmei , Yao Jian , Zhao Dong , Li Debao
Published: September 2008

Rice endosperm plays a very important role in seedling germination and determines the qualities of rice grain. Although studies on specific gene categories in endosperm have been carried out, global view of gene expression at a transcription level in rice endosperm is still limited. To gain a better understanding of the global and tissue‐specific gene expression profiles in rice endosperm, a cDNA library from rice endosperm of immature seeds was sequenced. A cDNA array was constructed based on the tentative unique transcripts derived from expression sequence tag (EST) assembling results and then hybridized with cDNAs from five different tissues or organs including endosperm, embryo, leaf, stem and root of rice. Significant redundancy was found for genes encoding prolamin, glutelin, allergen, and starch synthesis proteins, accounting for ∼34% of the total ESTs obtained. The cDNA array revealed 87 significantly expressed genes in endosperm compared with the other four organs or tissues. These genes included 13 prolamin family proteins, 17 glutelin family proteins, 12 binding proteins, nine catalytic proteins and four ribosomal proteins, indicating a complicated biological processing in rice endosperm. In addition, Northern verification of 1,4‐alpha‐glucan branching enzyme detected two isoforms in rice endosperm, the larger one of which only existed in endosperm.
Genome‐wide Characterization of Long Terminal Repeat ‐retrotransposons in Apple Reveals the Differences in Heterogeneity and Copy Number between Ty1‐copiaand Ty3‐gypsyRetrotransposons
Authors: Sun Hai‐Yue , Dai Hong‐Yan , Zhao Gui‐Ling , Ma Yue , Ou Chun‐Qing , Li He , Li Lin‐Guang , Zhang Zhi‐Hong
Published: September 2008

The conserved domains of reverse transcriptase (RT) genes of Ty1‐copiaand Ty3‐gypsygroups of long terminal repeat (LTR) retrotransposons were isolated from theMalus domesticagenome using degenerate oligonucleotide primers. Sequence analysis showed that 45% of Ty1‐copiaand 63% of Ty3‐gypsyRT sequences contained premature stop codons and/or indels disrupting the reading frame. High heterogeneity among RT sequences of both Ty1‐copiaand Ty3‐gypsygroup retrotransposons was observed, but Ty3‐gypsygroup retrotransposons in the apple genome are less heterogeneous than Ty1‐copiaelements. Retrotransposon copy number was estimated by dot blot hybridizations for Ty1‐copia(∼5 000) and Ty3‐gypsy(∼26 000). All elements of the two types of LTR retrotransposons comprise approximately 38% of theM. domesticagenome, with the Ty3‐gypsygroup contribution being higher (33.5%) than the Ty1‐copiaone (4.6%). Transcription was not detected by reverse transcription‐polymerase chain reaction for either Ty1‐copiaor Ty3‐gypsyretrotransposons in the leaves of plantsin vitroor in leaf explants cultured on medium supplemented with high concentration benzylaminopurine. This research reveals the differences in heterogeneity and copy number between Ty1‐copiaand Ty3‐gypsyretrotransposons in the apple genome. Ty1‐copiaretrotransposon has higher heterogeneity than Ty3‐gypsyretrotransposon, but the latter has a higher copy number, which implies that Ty3‐gypsyretrotransposons may play a more important role in the apple genome evolution.
Pretreatment with insulin before ischaemia reduces infarct size in Langendorff‐perfused rat hearts
Authors: Fuglesteg B. N. , Tiron C. , Jonassen A. K. , Mjøs O. D. , Ytrehus K.
Published: September 2008

Aim:  To compare the possible role of Akt and mammalian target of rapamycin (mTOR) in mediating cardioprotection against ischaemia under three different conditions: (1) During ischaemic preconditioning (IPC), (2) when insulin was given as a pretreatment agent (InsPC) and (3) when insulin was given as a reperfusion cell survival agent (InsR).

Methods:  Isolated perfused rat hearts were subjected to IPC (3 × 5 min) or InsPC (50 mU mL−1; 3 × 5 min), before 30 min of regional ischaemia followed by 120 min of reperfusion ± 1L‐6‐hydroxymethyl‐chiro‐inositol‐2‐[(R)‐2‐O‐methyl‐3‐O‐octadecylcarbonate] (HIMO) (20 μm; Akt inhibitor) or rapamycin (1 nm; mTOR inhibitor). In addition, insulin (3 mU mL−1) was given at the onset of reperfusion, ±HIMO or rapamycin. Risk zone (R) and infarct size (I) were determined with Evans blue and tetrazolium staining respectively. Western blot analysis was performed on tissue from Langendorff‐perfused rat hearts and cell lysates from cultured HL1 cells.

Results:  IPC, InsPC and InsR treatment resulted in a significant reduction in infarct size compared to controls (all P < 0.05). This protective effect of IPC and insulin was abolished by the inhibitors. However, the putative Akt inhibitor, although capable of abolishing cardioprotection induced by insulin, was not able to inhibit insulin‐induced phosphorylation of Akt in Langendorff‐perfused rat hearts and cultured HL1 cells. The target for this compound therefore remains to be determined.

Conclusion:  IPC and insulin (either as InsPC or InsR) appear to activate mTOR, and this kinase seems to play an essential role in cardioprotection against ischaemia and reperfusion injury as rapamycin blocked the protection.
The role of the α‐adrenergic receptor in the leg vasoconstrictor response to orthostatic stress
Authors: Kooijman M. , Rongen G. A. , Smits P. , Van Kuppevelt H. J. M. , Hopman M. T. E.
Published: September 2008

Aim: The prompt increase in peripheral vascular resistance, mediated by sympathetic α‐adrenergic stimulation, is believed to be the key event in blood pressure control during postural stress. However, despite the absence of central sympathetic control of the leg vasculature, postural leg vasoconstriction is preserved in spinal cord‐injured individuals (SCI). This study aimed at assessing the contribution of bothcentralandlocalsympathetically induced α‐adrenergic leg vasoconstriction to head‐up tilt (HUT) by including healthy individuals and SCI, who lackcentralsympathetic baroreflex control over the leg vascular bed.

Methods: In 10 controls and nine SCI the femoral artery was cannulated for drug infusion. Upper leg blood flow (LBF) was measured bilaterally using venous occlusion strain gauge plethysmography before and during 30° HUT throughout intra‐arterial infusion of saline or the non‐selective α‐adrenergic receptor antagonist phentolamine respectively. Additionally, in six controls the leg vascular response to the cold pressor test was assessed during continued infusion of phentolamine, in order to confirm complete α‐adrenergic blockade by phentolamine.

Results: During infusion of phentolamine HUT still caused vasoconstriction in both groups: leg vascular resistance (mean arterial pressure/LBF) increased by 10 ± 2 AU (compared with 12 ± 2 AU during saline infusion), and 13 ± 3 AU (compared with 7 ± 3 AU during saline infusion) in controls and SCI respectively.

Conclusion: Effective α‐adrenergic blockade did not reduce HUT‐induced vasoconstriction, regardless of intact baroreflex control of the leg vasculature. Apparently, redundant mechanisms compensate for the absence of sympathetic α‐adrenoceptor leg vasoconstriction in response to postural stress.
The Talk of Tamils in Multilingual Montreal: A Study of Intersecting Language Ideologies in Nationalist Quebec
Authors: Das Sonia
Published: September 2008

In Montreal, racial, caste, socioeconomic, and gender inequalities are often masked as neutral‐seeming linguistic differences of dialect, register, and accent. These sociolinguistic hierarchies are upheld by intersecting language ideologies, or essentialised beliefs about language use and ethnic identity. Quebec nationalist and multicultural policies endorse language ideologies of linguistic purity and sociolinguistic compartmentalisation to depict a cohesive nation while maintaining its racial and ethnic distinctions. Similarly, Montreal Tamil diaspora leaders encourage different Tamil‐speaking groups to participate in sociolinguistically segregated domains to preserve purist linguistic standards and maintain socioeconomic, caste, and gender distinctions. Heritage language programmes reproduce these language‐based distinctions for differentiating between types of Québécois citizens, while Montreal Tamil youth selectively challenge or endorse such prescriptions to produce a range of social identities and linguistic practices that correspond to their experiences as ethnic and racial minorities.
Religion, Ethnicity and Immigrant Integration: ‘Latino’ Lutherans versus ‘Mexican’ Catholics in a Midwestern City
Authors: Freier Luisa Feline
Published: September 2008

Although the majority of Latin American immigrants to the United States are Roman Catholics, increasing numbers of Latinos are converting to Protestantism. To understand the incentives for, and any possible integration effects of, immigrants' religious conversion, it is crucial to examine not only the religious but also the social boundaries of new immigrant congregations. This article examines the class‐based but ethnically labeled boundary construction of a Latino Lutheran towards a Latino Roman Catholic congregation in Madison, Wisconsin. The de facto ethnicised class differentiation via denominational choice shows that first: for ethnic discrimination to occur, no exclusive and imperative categories are needed, second: socioeconomic identification can superimpose religious and ethno‐cultural feelings of belonging, and third: the formation of a more liberal and higher educated ‘Latino’ Lutheran community facilitates the civic integration of its worshippers into the broader community based on the political mobilisation of panethnic identification.
The Shifting Landscapes of ‘Nationalism’
Authors: Smith Anthony D.
Published: September 2008

The field of study that comprises nations and nationalism is often seen as riven by a conflict between ‘modernists’ and their opponents. In fact, the field is far more fragmented than such a characterisation suggests. From the very first normative critical essays 150 years ago, it has been composed of shifting landscapes in which different approaches and perspectives overlap and cross‐cut each other like intersecting monologues. While there was a short period of engagement in the 1980s, a ‘classic debate’ between modernists, perennialists and ethno‐symbolists who embraced a macro‐analytic framework and a causal‐historical methodology, the familiar landscape has radically shifted to reveal a series of deconstructionist strategies and techniques; and while rational choice theories, among others, continue to embrace causal‐historical analysis, there has been a rejection in many quarters of both macro‐analytic narratives and causal‐historical analysis. The new anti‐essentialist strategies include feminist critiques, the study of everyday nationhood, the hybridisation of national identities, and debates about the ‘ethics of nationalism’ which echo earlier critiques. Above all, there is a new concern with the application of globalising trends to nations and nationalism, and especially with the role of nations without states, and the impact of supranationalism, large‐scale migration and ‘religious nationalisms’.
The Role of Ukrainian Museums in the United States Diaspora in Nationalising Ukrainian Identity
Authors: Kochman Adrienne
Published: September 2008

Ukrainian museums in the United States diaspora have attempted to construct a culturally authentic history outside Ukraine itself where, for the better part of the twentieth century, Ukrainian artistic endeavors were defined within a russified Soviet framework. Established largely by third wave post‐World War II Ukrainian immigrants interested in seeing an independent Ukraine, these museums have been a symbolic testament to democratic self‐definition. A separate Ukraine pavilion at the Century of Progress Exposition in Chicago of 1933 set an earlier precedent in its representation of Ukraine as an autonomous nation. This affirmed later permanent museums which collected indigenous Ukrainian folk art and artifacts as well as modern art – created by native Ukrainians and those of the diaspora – in opposition to the official Soviet Socialist Realist canon. Ukrainian independence in 1991 and increased national awareness after 2004 elections realigned these museums' mission from a cultural refuge to active participants in the new nation‐building process.
Assessment of hepatic steatosis and hepatic tissue blood flow by xenon computed tomography in nonalcoholic steatohepatitis
Authors: Kobayashi Minoru , Suzuki Michihiro , Ikeda Hiroki , Takahashi Hideaki , Matsumoto Nobuyuki , Maeyama Shiro , Sase Shigeru , Iino Shiro , Itoh Fumio
Published: September 2008

Aim: The diagnosis of non‐alcoholic steatohepatitis (NASH) can be difficult using blood tests and imaging studies. Histological diagnosis by liver biopsy remains the gold standard of NASH diagnosis. There is an urgent need to develop and validate simple, reproducible, noninvasive tests to accurately assess NASH stage and grade. We assess the usefulness of xenon computed tomography (Xe‐CT), as a non‐invasive method of quantitatively and visually determining hepatic tissue blood flows (TBFs), and xenon solubility (λ value) simultaneously with TBF, in the evaluation of NASH pathophysiology.

Methods: Histological severity of fatty changes and severity of fibrosis based on Brunt's classification were determined in 38 NASH patients. We evaluated correlations between the grade of fatty changes and λ value, and correlations between the stage of fibrosis and TBFs.

Results: The λ value showed significant positive correlations with both grade of steatosis (r = 0.813,P < 0.001) and each 10% range of histological fatty infiltration (r = 0.926,P < 0.001). A significant negative correlation was seen between λ value and the liver : spleen ratio (r = −0.835,P < 0.001). Portal venous tissue blood flow and total hepatic tissue blood flow showed significant negative correlations with the progression of fibrosis (r = −0.465,P < 0.01;r = −0.433,P < 0.01, respectively). Total hepatic tissue blood flow tended to decrease with progressing grade of steatosis.

Conclusion: Xe‐CT offers a convenient and objective method for evaluating fatty infiltration and changes in blood flow in the entire liver, and appears useful for detailed evaluation of patients with NASH.
Study on Total Instantaneous Blockage Accident for CEFR
Authors: Wang Zhe , Cao Xuewu
Published: September 2008

Chinese Experimental Fast Reactor (CEFR) is under construction in China. It is essential to investigate core disruptive accidents (CDAs) for the evaluation of CEFR’s safety characteristic. Accident of total instantaneous blockage in single assembly scale had already been modeled and analyzed. The degradation scenario had been calculated by a fluid-dynamics analysis code for liquid-metal fast reactors (LMFRs). For further investigation of accident process and influence to the near bundles, the seven assembly scale were then simulated and calculated. Total instantaneous blockage was assumed to occur in the center assembly under normal operating conditions and consequences to neighboring assemblies were studied. The result shows that the key events such as sodium boiling, clad melting, fuel particles relocation, hexcan failure and melt discharge into neighboring six assemblies symmetrically were adequately simulated. All the key events appeared in the same sequence as the single assembly simulation, while hexcan failure occurred later than that of single assembly simulation. The reason for the different timing may be the boundary condition assumption can influence the heat removal from the blocked assembly. The seven-assembly scale model can reduce the boundary condition’s uncertainties and help to give a better understanding and prediction of hypothetical accident scenario in subassembly blockage accidents for CEFR.
Tribocorrosion in PWR: A Parametric Approach
Authors: Kaczorowski D. , Combrade P. , Vernot J. Ph. , Beaudouin A.
Published: September 2008

A specific tribometer equipped for electrochemical measurements in pressurized high temperature water (PHTW) is being used to study the effect of the water chemistry on the wear rate of a stainless steel. First results indicate that a slightly acidic pH increases drastically the wear rate compared to slightly alkaline pH. The influence of hydrogen partial pressure and contact kinematics is also described.
Safety Criticality Standards Using the French CRISTAL Code Package: Application to the AREVA NP UO2 Fuel Fabrication Plant
Authors: Doucet M. , Terrasson L. Durand , Mouton J.
Published: September 2008

Criticality safety evaluations implement requirements to proof of sufficient sub critical margins outside of the reactor environment for example in fuel fabrication plants. Basic criticality data (i.e., criticality standards) are used in the determination of sub critical margins for all processes involving plutonium or enriched uranium. There are several criticality international standards, e.g., ARH-600, which is one the US nuclear industry relies on. The French Nuclear Safety Authority (DGSNR and its advising body IRSN) has requested AREVA NP to review the criticality standards used for the evaluation of its Low Enriched Uranium fuel fabrication plants with CRISTAL V0, the recently updated French criticality evaluation package. Criticality safety is a concern for every phase of the fabrication process including UF6 cylinder storage, UF6-UO2 conversion, powder storage, pelletizing, rod loading, assembly fabrication, and assembly transportation. Until 2003, the accepted criticality standards were based on the French CEA work performed in the late seventies with the APOLLO1 cell/assembly computer code. APOLLO1 is a spectral code, used for evaluating the basic characteristics of fuel assemblies for reactor physics applications, which has been enhanced to perform criticality safety calculations. Throughout the years, CRISTAL, starting with APOLLO1 and MORET 3 (a 3D Monte Carlo code), has been improved to account for the growth of its qualification database and for increasing user requirements. Today, CRISTAL V0 is an up-to-date computational tool incorporating a modern basic microscopic cross section set based on JEF2.2 and the comprehensive APOLLO2 and MORET 4 codes. APOLLO2 is well suited for criticality standards calculations as it includes a sophisticated self shielding approach, a Pij flux determination, and a 1D transport (Sn) process. CRISTAL V0 is the result of more than five years of development work focusing on theoretical approaches and the implementation of user-friendly graphical interfaces. Due to its comprehensive physical simulation and thanks to its broad qualification database with more than a thousand benchmark/calculation comparisons, CRISTAL V0 provides outstanding and reliable accuracy for criticality evaluations for configurations covering the entire fuel cycle (i.e. from enrichment, pellet/assembly fabrication, transportation, to fuel reprocessing). After a brief description of the calculation scheme and the physics algorithms used in this code package, results for the various fissile media encountered in a UO2 fuel fabrication plant will be detailed and discussed.
The Use of ARMA Models in Earthquake Response Spectra
Authors: Brahimi Malek , Berri Sidi
Published: September 2008

Structural design spectra are based on smoothed linear response spectra obtained from different events scaled by their peak values. Such an approach does not incorporate other characteristics of the excitation represented by measured data. This study investigate the use of non-stationary models which can be considered characteristic and representative of specific historical earthquakes. An earthquake record is regarded as a sample realization from a population of such samples, which could have been generated by the stochastic process characterized by an Autoregressive Moving Average (ARMA) model. ARMA models are developed for four major earthquakes after processing by a variance stabilizing transformation. Samples of acceleration records are generated for each event. In this earthquake modeling procedure, parameters describing the modulating function of the record and the stabilized series are estimated. Maximum displacement ductility demand and normalized hysteretic energy demand for linear and stiffness softening single degree of freedom system systems are computed for the samples generated for each event. The sensitivity and dependence of demand spectra on earthquake model characteristics are examined to develop a response prediction model. Non linear response analysis of the four events indicates that ARMA (2,1) process using samples of twenty simulated earthquakes provide a reliable description of the information contained within acceleration records. Empirical relationships for displacement ductility and Normalized hysteretic energy demand spectra are developed.
Power Recapture and Power Uprate in NPPs With Process Data Reconciliation in Accordance With VDI 2048
Authors: Langenstein Magnus
Published: September 2008

The determination of the thermal reactor power is traditionally done by establishing the heat balance: • for a boiling water reactor (BWR) at the interface of reactor control volume and heat cycle; • for a pressurized water reactor (PWR) at the interface of the steam generator control volume and turbine island on the secondary side. The uncertainty of these traditional methods is not easy to determine and it can be in the range of several percent. Technical and legal regulations (e.g. 10CFR50) cover an estimated instrumentation error of up to 2% by increasing the design thermal reactor power for emergency analysis to 102% of the licensed thermal reactor power. Basically, the licensee has the duty to warrant at any time operation inside the analysed region for thermal reactor power. This is normally done by keeping the indicated reactor power at the licensed 100% value. A better way is to use a method which allows a continuous warranty evaluation. The quantification of the level of fulfilment of this warranty is only achievable by a method which: • is independent of single measurements accuracies; • results in a certified quality of single process values and for the total heat cycle analysis; • leads to complete results including 2-sigma deviation especially for thermal reactor power. This method, which is called ‘process data reconciliation based on VDI 2048 guideline’, is presented here [1, 2]. The method allows to determine the true process parameters with a statistical probability of 95%, by considering closed material, mass- and energy balances following the Gaussian correction principle. The amount of redundant process information and complexity of the process improves the final results. This represents the most probable state of the process with minimized uncertainty according to VDI 2048. Hence, calibration and control of the thermal reactor power are possible with low effort but high accuracy and independent of single measurement accuracies. Furthermore, VDI 2048 describes the quality control of important process parameters. Applied to the thermal reactor power, the statistical certainty of warranting the allowable value can be quantified. This quantification allows keeping a safety margin in agreement with the authority. This paper presents the operational application of this method at an operating plant and describes the additional use of process data reconciliation for acceptance tests, power recapture and system and component diagnosis.
The Application of Structural Materials Data From the BN-350 Fast Reactor to Life Extension of Light Water Reactors
Authors: Romanenko O. G. , Kislitsin S. B. , Maksimkin O. P. , Shiganakov Sh. B. , Chumakov Ye. V. , Dumchev I. V.
Published: September 2008

This paper describes the results of investigations of 08Cr16Ni11Mo3 (AISI 316 steel analogue) austenitic stainless steel irradiated in BN-350 breeder reactor at irradiation conditions close to that for Light Water Reactor (LWR) Internals. The pores were found in 08Cr16Ni11Mo3 steel irradiated at temperature 280°C up to rather low damage 1.3 dpa and with dose rate 3.9×10−9 dpa/s. There were obtained dose rate dependencies of yield strength, ultimate strength and ductility for 08Cr16Ni11Mo3 steel irradiated up to 7–13 dpa at 302–311°C. These dependencies show a decrease in both yield strength and ultimate strength when dose rate decreases. There was observed an apparent decrease in total elongation when dose rate decreases, which was presumably connected with the pores formation in the steel at low dose rates.
Design and Construction of the Amplifier for Nuclear Radiation Detectors
Authors: Ebadati Javad , Shahabi Iraj , Rezvanifard Mahdi
Published: September 2008

A nuclear detection spectroscopy amplifier, with professional properties was designed, constracted and compared with an ORTEC amplifier in a spectroscopy system at the nuclear lab. Its performance had a good compatibility compared to the ORTEC model 570 amplifier and even more efficent in the taken counts. This paper discusses the steps in the design and construction of this instrument.
Calculation and Experiment of Adding Top Beryllium Shims for Iran MNSR
Authors: Ebadati Javad , Shahabi Iraj , Rezvanifard Mehdi
Published: September 2008

M iniature Neutron Source Reactor which is called MNSR were put into operation on June 1994 in Esfahan Nuclear Technology Center (ENTC). At that time the excess reactivity at the cold condition was 3.85 mk. After 7 years of operation and fuel consumption the reactivity was reduced to 2.90 mk. To compensate this reduction and upgrade the reactor, Beryllium Shim were used at the top of the core. This paper discusses the steps for this accurate and sensitive task. Finally a layer of 1.5 mm Beryllium were added to restore the reactor life.
Thermohydraulic and Safety Analysis for CARR Under Station Blackout Accident
Authors: Tian Wenxi , Qiu Suizheng , Su Guanghui , Jia Dounan , Liu Xingmin
Published: September 2008

A thermohydraulic and safety analysis code (TSACC) has been developed using Fortran90 language to evaluate the transient thermohydraulic behaviors and safety characteristics of the China Advanced Research Reactor (CARR) under Station Blackout Accident (SBA). For the development of TSACC, a series of corresponding mathematical and physical models were considered. Point reactor neutron kinetics model was adopted for solving reactor power. All possible flow and heat transfer conditions under station blackout accident were considered and the optional models were supplied. The usual Finite Difference Method (FDM) was abandoned and a new model was adopted to evaluate the temperature field of core plate type fuel element. A new simple and convenient equation was proposed for the resolution of the transient behaviors of the main pump instead of the complicated four-quadrant model. Gear method and Adams method were adopted alternately for a better solution to the stiff differential equations describing the dynamic behaviors of the CARR. The computational result of TSACC showed the enough safety margin of CARR under SBA. For the purpose of Verification and Validation (V&V), the simulated results of TSACC were compared with those of Relap5/Mdo3. The V&V result indicated a good agreement between the results by the two codes. Because of the adoption of modular programming techniques, this analysis code is expected to be applied to other reactors by easily modifying the corresponding function modules.
Validation of IVA Computer Code for Flow Boiling Stability Analysis
Authors: Kolev Nikolay Ivanov
Published: September 2008

IVA is a computer code for modeling of transient multiphase, multi-component, non-equilibrium flows in arbitrary geometry including flow boiling in 3D nuclear reactors. This work presents part of the verification procedure of the code. We analyze the stability of flow boiling in natural circulation loop. Experimental results collected on the AREVA/FANP KATHY loop regarding frequencies, mass flows and decay ratio of the oscillations are used for comparison. The comparison demonstrates the capability of the code to successfully simulate such class of processes.
Combining Nuclear Power With Coal-to-Gasoline Conversion
Authors: Hamel H.-J. , Jaeger Walter , Termuehlen Heinz
Published: September 2008

With coal representing 95% and oil only 2.5% of the US fossil fuel reserves and with the abundant nuclear fuel reserves in the US, such combined plants should be built in the near future.
Design Strategy for Piping System of an Experimental Facility for Containment Studies
Authors: Mishra Rajesh , Agrawal M. K. , Vaze K. K. , Ghosh A. K.
Published: September 2008

An experimental facility is being set up at Bhabha Atomic Research Centre for studying the thermal-hydraulic behavior of Indian Pressurized Heavy water Reactors under normal and accidental conditions. The set up simulates the containment of the reactor and the Primary Heat Transport System (PHTS). In experimental set up, the PHTS simulation vessel is placed outside the containment building and the piping system connects it to the containment building. The steam-water mixture produced in the PHTS vessel will be discharged into the containment to simulate various postulated accidental conditions. The piping system consists of quick opening dual assembly rupture disk and valves. Various layouts of the piping system had been studied with due considerations to the site constraints. Rupture disk location has been finalized considering its operational requirements. Supporting arrangement has been arrived at with due consideration to the various service load requirements. Subsequently, additional supports have been incorporated to increase system frequency. This paper deals with the various considerations made and strategy adopted for finalisation of layout and to meet the codal requirements.
Aperiodic Instability of a Once-Through Steam Generator with a Feedwater Line
Authors: Seo Jae-Kwang , Kang Han-Ok , Yoon Juhyeon , Kim Keung-Koo
Published: September 2008

Aperiodic (static) flow instability is an instability related to the change of a flow direction in individual steam generating U-shaped channels operating at given pressure difference. The nature of an aperiodic instability is close to a Ledinegg instability [1] related to the presence of multiple flows at the full hydraulic curve of a U-shaped channel. In this paper, the conditions for a reverse flow for a once-through steam generator (OTSG) with U-shaped modular feedwater line (MFL) are studied. From the results of the studies, it is revealed that the change of a flow direction in the MFL is due to the boiling of the feedwater in the downcomer branch of the U-shaped MFL and that multiple flows start in an area of the extremes corresponding to the minimum pressure difference of the hydraulic curves. Calculation models for predicting a threshold of an aperiodic instability for the OTSG of interest is proposed and the analysis results are compared with the experimental data.
Application Research of Two Real-Time Fault Diagnostic Methods in the Nuclear Power Plants
Authors: Xie Chun-Li , Liu Yong-Kuo , Xia Hong
Published: September 2008

In order to guarantee the safety of nuclear power plants (NPP), we built two real-time fault diagnosis systems adopting VISUAL BAS6.0 programming language, which apply neural network technolog and data fusion technology respectively. The fault diagnosis systems interchange data with the simulator timely utilizing communication interface. We insert faults on simulator to test the two systems on line. The advantages and disadvantages are illuminated and contrasted through analyzing the faults diagnostic results off- line, which establish the foundation for the further research and application to the fault diagnosis system of the nuclear power plants.
Methodology of Local Instantaneous Interfacial Velocity Measurement in Multi-Dimensional Two-Phase Flow
Authors: Shen Xiuzhong , Mishima Kaichiro , Nakamura Hideo
Published: September 2008

Since the transport of momentum, heat and mass tightly links with local interfacial characteristics it is essential to know the local interfacial parameters in various two-phase flows. The interfacial velocity plays a determinant role in determining the other interfacial parameters such as the interfacial area concentration and so on. It is accordingly one of the most important parameters in analyzing two-phase flow. However, it also is one of the most difficult parameters to measure up to now. Based on the application of the interfacial measurement theorem to several four-sensor probes, the present study established a theoretical foundation of the measurement method for the local instantaneous interfacial velocity in multidimensional two-phase flow by using three independent four-sensor probes. Since we can find three independent four-sensor probes in a multi-sensor probe, which has more than four sensors, by sharing the sensors of the first four-sensor probe with the sensors of the others, a five- or six-sensor probe including at least one set of three four-sensor combinations was recommended to measure the local instantaneous interfacial velocity, interfacial area concentration and so on in multidimensional two-phase flow. A six-sensor probe was developed and employed in the practical measurement in an air-water multi-dimensional two-phase flow in a pool. The six-sensor probe measurements were checked against the gas flow rate measurement using a rotameter and a manometer. The comparing results were very satisfactory.
Deep Atomic Binding (DAB) Approach in Interpretation of Fission Products Behavior in Terrestrial and Water Ecosystems
Authors: Ajlouni Abdul-Wali M. S.
Published: September 2008

A large number of studies and models were established to explain the fission products (FP) behavior within terrestrial and water ecosystems, but a number of behaviors were non understandable, which always attributed to unknown reasons. According to DAB hypothesis, almost all fission products behaviors in terrestrial and water ecosystems could be interpreted in a wide coincidence. The gab between former models predictions, and field behavior of fission products after accidents like Chernobyl have been explained. DAB represents a tool to reduce radiophobia as well as radiation protection expenses.
Comparisons of the Oxide Layer Between Static Liquid-Bismuth-Eutectic and Gas Environments
Authors: Zhang Jinsuo , Li Ning
Published: September 2008

The competition between corrosion and oxidation on a steel surface immersed in lead alloys with controlled oxygen leads to different oxide-layer characteristics as compared with those formed in gases. The presence of a liquid metal [liquid lead or lead-bismuth eutectic (LBE)] can either enhance or reduce the oxidation rate, resulting in different oxide growth rates and microstructures. Based on analysis of experimental results in static LBE/lead and gases under the same experimental conditions, we predict the oxide-layer structure and thickness as functions of immersion time and analyze the factors that play important roles in the oxidation process in LBE/lead. It is shown that there is a significant difference between the oxide formed in liquid lead alloys and in gases, including the oxide-layer structure. To generate a stable protective oxide layer on steel surfaces in LBE, the long-term corrosion effect, the supply of oxygen, and the penetration of the liquid metal into the structural materials or oxide layers must be taken into account.
Developing SCWR is the Most Feasible Way of Effectively Using Uranium Resources in China
Authors: Li Yulun
Published: September 2008

It is quite challenging to achieve 40 GWe of nuclear power installed capacity and another 18 GWe under construction by 2020 in China. This article analyzes the demand for uranium resources to achieve this goal, and discusses several optional advanced reactor types such as SCWR, HTGR and FBR/relevant fuel cycles for nuclear power development behind 2020 based on the practical demand for uranium resources and industrial capability. It is obvious that to develop SCWR in China is the most feasible option to effectively utilize and save uranium resources.
Industrial Safety and Accidents Prevention
Authors: Akbar Sajjad
Published: September 2008

Accident Hazards, dangers, losses and risk are what we would to like to eliminate, minimize or avoid in industry. Modern industries have created many opportunities for these against which man’s primitive instincts offer no protection. In today’s complex industrial environment safety has become major preoccupation, especially after the realization that there is a clear economic incentive to do so. Industrial hazards may cause by human error or by physical or mechanical malfunction, it is very often possible to eliminate the worst consequences of human error by engineering modification. But the modification also needs checking very thoroughly to ensue that it has not introduced some new and unsuspected hazard.
CFD Simulation of Slug Mixing in VVER-1000 Reactor
Authors: Vyskocil Ladislav
Published: September 2008

Recently, the safety analyses of VVER and PWR reactors have dealt with the possibility of reactivity-induced accidents related to the penetration of a water slug with low boron concentration into the reactor core. Loop seals at the reactor coolant pump (RCP) suction are the most likely places for the formation of these slugs. The slug is formed in the loop when there is neither natural nor forced circulation. When the circulation is restored, the slug travels towards the reactor and causes an insertion of positive reactivity in the core. This report deals with a CFD simulation of the most dangerous event—the start-up of the first RCP. Only several seconds are needed for slug to reach the core and the operator has no time for corrective action. Mixing of slug on its way to the core can reduce the danger of core recriticality. The primary objective of this study was to find out whether the FLUENT 6 CFD code is capable of predicting the mixing in the cold leg, downcomer and lower plenum as the slug moves toward the reactor core. Numerical simulations were based on mixing tests performed on 1:5 scale model of VVER-1000 reactor at the Gidropress Design Bureau, Russia. In the physical mixing tests, temperature was substituted for Boron concentration through the use of hot and cold water. The time history of core inlet average temperature was calculated by FLUENT and was found to be in good qualitative agreement with experimental data. This work was carried out as part of the EU project FLOMIX-R, Work Package 4.
Failure Pressure Estimates of Steam Generator Tubes Containing Wear-Type Defects
Authors: Chang Yoon-Suk , Kim Jong-Min , Huh Nam-Su , Kim Young-Jin , Hwang Seong-Sik , Kim Joung-Soo
Published: September 2008

It is commonly requested that steam generator tubes with defects exceeding 40% of wall thickness in depth should be plugged to sustain all postulated loads with appropriate margin. The critical defect dimensions have been determined based on the concept of plastic instability. This criterion, however, is known to be too conservative for some locations and types of defects. In this context, the accurate failure estimation for steam generator tubes with a defect draws increasing attention. Although several guidelines have been developed and are used for assessing the integrity of defected tubes, most of these guidelines are related to stress corrosion cracking or wall-thinning phenomena. As some of steam generator tubes are also failed due to fretting and so on, alternative failure estimation schemes for relevant defects are required. In this paper, three-dimensional finite element (FE) analyses are carried out under internal pressure condition to simulate the failure behavior of steam generator tubes with different defect configurations; elliptical wastage type, wear scar type and rectangular wastage type defects. Maximum pressures based on material strengths are obtained from more than a hundred FE results to predict the failure of the steam generator tube. After investigating the effect of key parameters such as wastage depth, wastage length and wrap angle, simplified failure estimation equations are proposed in relation to the equivalent stress at the deepest point in wastage region. Comparison of failure pressures predicted according to the proposed estimation scheme with some corresponding burst test data shows good agreement, which provides a confidence in the use of the proposed equations to assess the integrity of steam generator tubes with wear-type defects.
Main Generator Seal Oil Supply Reliability Improvements at Southern California Edison’s San Onofre Nuclear Generating Station
Authors: Simma Fred Y. , Chetwynd Russell J. , Rowe Stuart A.
Published: September 2008

This paper presents the justification for the approach, details and results of the Main Generator Seal Oil System reliability enhancements on the San Onofre Nuclear Generating Station, SONGS. The SONGS, Unit 3 experienced substantial turbine damage in early 2001 after the turbine bearings lubrication oil supply failed. During a loss of off-site power incident, power was lost to the two AC powered turbine lubrication oil pumps due to a breaker failure in the switchgear and the DC powered emergency bearing lubricating oil pump failed to start due to a breaker trip. The SONGS turbine generators coasted down from full speed to a full stop without lubricating oil. This resulted in significant bearing, journal and steam path damage that required a four-month duration repair outage during a time period where electricity was in short supply in the State of California. The generator hydrogen sealing system remained operable during this event, however it was recognized during the event follow up investigation that this system had vulnerabilities to failure similar to the bearing lubrication system. In order to prevent a reoccurrence of this extremely costly event, SONGS has taken actions to modify both of these critical turbine generator systems by adding additional, continuously operating pumps with a new, independent power source and independently routed cables. The main challenge was to integrate the additional equipment into the existing lubrication and seal oil systems. The lubrication Oil System was the first system to be retrofitted and these results already have been presented. Reference 2. This paper provides the result of the reliability enhancements for the Main Generator Seal Oil System, which concludes the turbine/generator critical oil systems reliability improvements, performed by SONGS. It is worth noting that the design team discovered and corrected a number of other significant operational issues, which had been present from the early days and also learned a great deal of detailed information about this vital system during the project. The SONGS approach and findings are discussed in this paper, as well as a summary of the work performed. This technical paper will be of interest to utilities with a need to improve turbine generator reliability issues.
The Core Melt Stabilization Concept of the EPR and Its Experimental Validation
Authors: Fischer Manfred
Published: September 2008

The strategy of the European Pressurized Water Reactor (EPR) to avoid severe accident conditions is based on the improved defense-in-depth approaches of the French “N4” and the German “Konvoi” plants. In addition, the EPR takes measures, at the design stage, to drastically limit the consequences of a postulated core-melt accident. The latter requires a strengthening of the confinement function and a significant reduction of the risk of short- and long-term containment failure. Scenarios with potentially high mechanical loads and large early releases like: high-pressure RPV failure, global hydrogen detonation, and energetic steam explosion must be prevented. The remaining low-pressure sequences are mitigated by dedicated measures that include hydrogen recombination, sustained heat removal out of the containment, and the stabilization of the molten core in an ex-vessel core catcher located in a compartment lateral to the pit. The spatial separation protects the core catcher from loads during RPV failure and, vice versa, eliminates concerns related with its unintended flooding during power operation. To make the relocation of the melt into the core catcher scenario-independent and robust against the uncertainties associated with in-vessel molten pool formation and RPV failure, the corium is temporarily retained, accumulated and conditioned in the pit during interaction with a sacrificial concrete layer. Spreading of the accumulated molten pool is initiated by penetrating a concrete plug in the bottom. The increase in surface-to-volume ratio achieved by the spreading process strongly enhances quenching and cool-down of the melt after flooding. The required water is passively drained from the IRWST. After availability of the containment heat removal system the steam from the boiling pool is re-condensed by sprays. The CHRS can also optionally cool the core catcher directly, which, in consequence, establishes a sub-cooled pool near-atmospheric pressure levels in the containment. The described concept rests on a large experimental knowledge base which covers all main phenomena involved, including melt interaction with structural material, melt spreading, melt and quenching, as well as the efficacy of the core catcher cooling. Besides giving an overview of the EPR core melt mitigation concept, the paper summarizes its R&D bases and describes which conclusions have been drawn from the various experimental projects and how these conclusions are used in the validation of the EPR concept.