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Generally, the thermal hydraulic (TH) codes need the results of Neutron Kinetics (NK) codes providing the reactivity properties to calculate neutron flux. Then the TH codes perform the safety analyses obtaining the responses of pressure, temperature, or water level. Two kinds of different codes calculate different physical behaviors sequentially and separately. Simultaneously computing thermal hydraulic and neutron kinetics behaviors can enhance the accuracy of the analysis. Hence, it is crucial to develop the TH-NK coupled model. This study presents the capability of the TH-NK coupled model, developed by TRACE (TRAC/RELAP Advanced Computational Engine) and PARCS (Purdue Advanced Reactor Core Simulator), for the BWR-4 nuclear power plant. The establishment of the TRACE/PARCS model presented the nodal and component modeling methodologies. This model was used to simulate two startup tests of high power level system transients. Principal system responses, calculated by the TRACE/PARCS model, were compared with the measured data in startup tests and the results of the point kinetic calculation of the TRACE (TRACE/PK) to evaluate the model. The evaluation shows that the TRACE/PARCS model can simulate the interaction between thermal hydraulic and neutron kinetics phenomena and predict the transients suitably. Through the comparison, the TRACE/PARCS model can be confident doing the analyses of normal and abnormal operational transients to predict the transient responses.

An integral analysis methodology for BWR ATWS has been developed. The method covers main scopes about ATWS events, including radiological consequence, primary system integrity, fuel integrity, containment integrity, and long-term shutdown and cooling capability. The primary techniques about this methodology were described herein. The methodology has been applied on Kuosheng nuclear power station to show the applicability. Under this framework, some suggestions were proposed for further development of this methodology. This methodology can give a way to evaluate safety of BWR plants confidently. Further, it can be a tool for developing emergency procedures about severe accidents, or exploring strategies and checking their effectiveness.

This study established an RCS-Containment coupled model that integrates the reactor coolant system (RCS) and the containment system by using the TRACE code. The coupled model was used in both short-term and long-term loss of coolant accident (LOCA) analyses. Besides, the RELAP5/CONTAN model that only contains the containment system was also developed for comparison. For short-term analysis, three kinds of LOCA scenarios were investigated: the recirculation line break (RCLB), the main steam line break (MSLB), and the feedwater line break (FWLB). For long-term analysis, the dry-well and suppression pool temperature responses of the RCLB were studied. The analysis results of RELAP5/CONTAN and TRACE models are benchmarked with those of FSAR and RELAP5/GOTHIC models, and it appears that the results of the above four models are consistent in general trends.

In this research, the analysis methodology for Maanshan PWR nuclear power plant (NPP) ATWS (Anticipated Transient Without Scram) is established by using RADTRAD code. This methodology can evaluate the dose at Exclusion Area Boundary (EAB), Low Population Zone (LPZ), and control room for the Maanshan ATWS. In addition, there are four leakage pathways in the Maanshan ATWS that are containment leakage, containment low volume purge, steam generator leakage, and ESF leakage. Therefore, for these leakage pathways, the RADTRAD models are established. Finally, according to the analysis results, they are below the criteria of 10 CFR 100.11 for the EAB and LPZ and Standard Review Plan (SRP) for the control room. Additionally, the steam generator leakage gives the maximum dose in these leakage pathways.

IIST (Institute of Nuclear Energy Research Integral System Test) facility is a RHRP (Reduced-Height and Reduced-Pressure) facility for the three-loop PWR (Pressurized Water Reactor) NPP (Nuclear Power Plant) Maanshan. This test facility was established in 1992 for safety studies of the Maanshan NPP. TRACE is an advanced thermal hydraulic code which is still developed and updated by U.S. NRC. So, validation of specific models against experiments is still necessary. In this paper, cooldown experiments in IIST facility are used to validate the TRACE models. Additionally, the results of TRACE calculations are compared to results of RELAP5 calculations. This comparison shows that the calculations of TRACE are in good agreement to the data of IIST experiments and to the calculational results of RELAP5. So, TRACE can be used to simulate cooldown transients.

IIST (Institute of Nuclear Energy Research Integral System Test) facility is a RHRP (Reduced-Height and Reduced-Pressure) facility for the three-loop PWR (Pressurized Water Reactor) NPP (Nuclear Power Plant) Maanshan. This test facility was established in 1992 for safety studies of the Maanshan NPP. TRACE is an advanced thermal hydraulic code which is still developed and updated by U.S. NRC. So, validation of specific models against experiments is still necessary. In this paper, cooldown experiments in IIST facility are used to validate the TRACE models. Additionally, the results of TRACE calculations are compared to results of RELAP5 calculations. This comparison shows that the calculations of TRACE are in good agreement to the data of IIST experiments and to the calculational results of RELAP5. So, TRACE can be used to simulate cooldown transients.

Kuosheng Nuclear Power Plant (NPP) is a BWR/6 plant in Taiwan. First, this study focuses on the establishment of the TRACE/SNAP model for Kuosheng. To check the system response of the Kuosheng TRACE/SNAP model, the Final Safety Analysis Report (FSAR) and startup tests data are used to assess the TRACE/SNAP model. The TRACE predictions are consistent with the FSAR and startup tests data. This indicates that there is a respectable accuracy in the TRACE/SNAP model of Kuosheng NPP. Second, this study also focuses on the application of the TRACE/SNAP model in the core shroud leakage. The Kuosheng NPP TRACE/SNAP model is used to perform the analysis of core shroud leakage. The TRACE results imply that Kuosheng NPP is in a safe situation when the core shroud leakage transient occurs.

AbstractIn order to analyze the boiling and capillary limitations of two-phase heat transport devices, the existing models developed by Chi and Peterson and the existing experimental data carried out with various micro channel wick structures from literature were collected for benchmark. It was found that the dominant parameters for boiling and capillary limitations were the nucleation sites and structure geometries of the micro channels, and important parameters were considered to modify the models empirically. It was also found that for micro channel structures the inclined angle is sensitive to the capillary limitations and not to boiling limitations. By properly estimating the nucleation sites and empirical coefficients for micro channels needed by the newly modified models, the boiling and capillary limitations can be accurately predicted, and hence the applicability of the modified models is confirmed. Based on this, a numerical analysis was then carried out to investigate the trends of boiling and capillary limitations of the micro channel wick structures. Effects of the channel geometries and arrangement were taken into account, including the aspect ratio and structure size of the micro channels. Furthermore, the effects of inclined angle and contact angle were also analyzed. The present results can provide a design reference of performance trends of micro channel wick structures.

In this research, the TRACE/SNAP model of Lungmen ABWR nuclear power plant (NPP) has been established for the simulation and analysis of ultimate response guideline (URG). The main actions of URG are depressurization and low pressure water injection of reactor and containment venting. This research focuses to assess the URG utility of Lungmen NPP under Fukushima-like conditions. This study consists of three steps. The first step is the establishment of Lungmen NPP TRACE/SNAP model. In order to evaluate the system response of TRACE/SNAP model, FSAR data (MSIV closure and loss of feedwater flow transient) were used to compare with the results of TRACE. The second step is the URG simulation and analysis under Fukushima-like conditions by using Lungmen NPP TRACE/SNAP model. In this step, the no URG case was also performed in order to evaluate the URG effectiveness of Lungmen NPP. In order to confirm the mechanical property and integrity of fuel rods, the final step is FRAPTRAN analysis. According to TRACE analysis results, the URG can keep the peak cladding temperature (PCT) below the criteria 1 088.7 K under Fukushima-like conditions which indicates that Lungmen NPP can be controlled in a safe situation. Nevertheless, if Lungmen NPP does not perform the URG under Fukushima-like conditions, the water level may drop lower than TAF after 1 100 s which means a safety issue about the fuel rods may be generated. The analysis results of FRAPTRAN also indicate the integrity of fuel rods cannot be kept under the above conditions.

This study aims to develop the Maanshan Pressurized Water Reactor (PWR) analysis model by using the TRACE (TRAC/RELAP Advanced Computational Engine) code. By analyzing the Large Break Loss of Coolant Accident (LBLOCA) sequence, the results are compared with the Maanshan Final Safety Analysis Report (FSAR) data. The critical flow and Counter Current Flow Limitation (CCFL) play an important role in the overall performance of TRACE LBLOCA prediction. Therefore, the sensitivity study on the discharge coefficients of critical flow model and CCFL modeling among different regions are also discussed. The current conclusions show that modeling CCFL in downcomer has more significant impact on the peak cladding temperature than modeling CCFL in hot-legs does. No CCFL phenomena occurred in the pressurizer surge line. The best value for the multipliers of critical flow model would be 0.5 and the TRACE could consistently predict the break flow rate in the LBLOCA analysis as shown in FSAR.

For the nuclear power plant Lungmen (two blocks of Advanced Boiling Water Reactor (ABWR)) in Taiwan a plant model for the thermal hydraulic program TRACE (TRAC/RELAP Advanced Computational Engine) was developed. This model is and will be used for the simulation of normal and anomalous plant behaviour as well as for the simulation of incident scenarios. The presentation of this model is done in three steps: The first step is the development of a TRACE model of Lungmen nuclear power plant (NPP) which includes the vessel, the main steam lines and important control systems (such as the feedwater control system, recirculation flow control system, etc.). Key parameters were identified to refine the model further in the frame of a steady state analysis. The second step is the performance of TRACE transient analyses, such as MSIV closure direct scram (MSIVCD, MSIV = Main Steamline Isolation Valve) and loss of feedwater flow (LOFW). The above transient data of Final Safety Analysis Report (FSAR) are used to verify the Lungmen NPP TRACE model. The trends of their analysis results are roughly similar. It indicates that TRACE model is satisfying for the purpose of Lungmen NPP safety analyses. The third step is the prediction analysis of Lungmen NPP startup tests by using the TRACE model. The prediction analysis results of TRACE comply with the startup tests procedure criteria.

In this study, a bioprocess optimization problem was considered for a multiple‐stage extractive fermentation, including cell recycling, to produce lactic acid. The aim of the optimization problem is to obtain the maximum overall productivity, conversion and yield simultaneously, so that the optimization problem is formulated as a multi‐objective optimization procedure. The fuzzy goal attainment method was introduced to the multi‐objective optimization problem in order to obtain a trade‐off solution. The approach was also employed to determine the optimal design for two simplified continuous fermentation processes. From the computational results, the overall productivity for the fermentation processes including cell recycling, enabled a higher dilution rate so that the overall productivity was ca. thirteen‐fold higher than that of the continuous fermentation process without cell recycling.

Forty-nine patients (age > 50 years) with an acute abdomen and suspected appendicitis, but with atypical findings, were included in the study. After the intravenous injection of 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO) labelled white blood cells (WBCs), serial anterior images of the abdomen and pelvis were obtained after 30, 60, 120 and 240 min. Any abnormal localization of WBC accumulation in the right lower quadrant of the abdomen equal to or greater than bone marrow activity was considered positive. Twenty-five patients had positive WBC scans, all of whom underwent laparotomy. Twenty-three of these patients were shown to have appendicitis; the other 2 did not. The other 24 patients had a negative WBC scan, 2 of whom underwent laparotomy and were shown to have appendicitis; the other 22 patients did not undergo surgery and showed no evidence of appendicitis during follow-up. The overall sensitivity, specificity, accuracy, positive and negative predictive values of WBC scans for diagnosing appendicitis were as follows: 92.0, 91.7, 91.8, 92.0 and 91.7 respectively. In conclusion, 99Tcm-HMPAO-labelled WBC scans provide a rapid and highly accurate method for diagnosing appendicitis in older patients with equivocal clinical findings.

This paper presents comprehensive correlation equations of the local Nusselt numbers and surface shear stresses for laminar forced convection, natural convection, and mixed convection on vertical and horizontal flat plates which are maintained with uniform wall temperature or uniform surface heat flux. The correlation for pure forced convection and pure natural convection are very accurate for any Prandtl number between 0.001 and infinity. The correlations for mixed convection coincide very well with the numerical results over the entire regimes of mixed convection intensity and Prandtl number for the eight cases of the two plates with distinct thermal boundary conditions and buoyancy-assisting and-opposing flow conditions.

This paper proposed a proper inclination parameter and transformation variables for the analysis of free convection from an inclined plate with uniform surface heat flux to fluids of any Prandtl number. Very accurate numerical results and a simple correlation equation are obtained for arbitrary inclination from the horizontal to the vertical and for 0.001 =Pr=8. Maximum deviation between the correlated and calculated data is less than 1.2%.

Laminar mixed convection over a horizontal plate with uniform wall temperature or uniform wall heat flux is analyzed by introducing proper buoyancy parameters and transformation variables for fluids of any Prandtl number between 0.001 and 10,000. Both cases of buoyancy assisting and opposing flow conditions are investigated. For the buoyancy-assisting case, the obtained numerical results are very accurate over the entire range of mixed convection intensity from pure forced convection limit to pure free convection limit. For the buoyancy-opposing case, solutions are obtained from the forced convection limit to the point of breakdown.

Simultaneous heat and mass transfer in buoyancy-induced laminar boundary-layer flow along a vertical plate is studied for any ratio of the solutal buoyancy force to the thermal buoyancy force by using a new similarity transformation. The effects of the buoyancy ratio and Lewis number on the rates of heat and mass transfer are presented explicitly for most practical gaseous solutions (Pr=0.7, 0.21=Sc=2.1) and aqueous solutions (Pr=7, 140=Sc=1400). Very accurate correlations of the mass transfer and heat transfer rates are developed for the cases of single and combined buoyancy forces.

This paper has examined the validity of the analogies between heat transfer and fluid friction when they are applied to laminar forced convection on a flat plate. For the case of uniform wall temperature, all the analogies are valid for Prandtl number do not differ greatly from 1, and the Colburn analogy is consistent with numerical data forPr=1. However, the previous analogies are not valid for the case of uniform wall heat flux. For fluids ofPr=1 under uniform heating, the Colburn analogy factor is 0.72. In addition, these analogies are not applicable to the fluids of small Prandtl number. For the sake of completeness, this work has developed the analogies between heat and momentum transfer over the range of 0.001 =Pr = 0.1 for both the cases of constant wall temperature and heat flux.

Abstract:  Mixed convection heat transfer from a vertically moving plate to a flowing free stream is investigated. The plate moves either in parallel or reversely to the free stream; and the buoyancy force accelerates or retards the flow. An universal formulation can be obtained from which similarity and nonsimilarity equations for six limiting cases of forced, natural, and mixed convection can be readily reduced. Accurate finite-difference solutions and comprehensive correlations of heat transfer rate for 0.01≤Pr≤10000 are presented over the entire domains of mixed convection and relative velocity.

Abstract: Multiple steady-state solutions of natural convection in an inclined enclosure with a fluid layer and a heat-generating porous bed is investigated numerically by the finite volume method. The conservation equations for the porous layer are based on a general flow model which includes both the effects of flow inertia and friction. The flow in fluid layer is modeled by Navier–Stokes equations. The method of pseudo arc-length continuation is adapted in studying the effects of tilt angle on flow pattern and heat transfer. It is found that, in the whole domain of tilt angle, there exist two groups of solutions with quite different flow pattern and heat transfer behavior. The effects of aspect ratio on flow pattern and heat transfer have also been studied.

Helium was implanted in type 316 stainless steel, through tritium decay, to levels of 0. 18, 2. 5, 27, 105, and 256 atomic parts per million (appm). Bead-on-sheet welds were then made using the gas tungsten arc (GTA) process. Intergranular cracking occurred in the heat-affected zones (HAZs) of specimens with helium concentrations equal to or greater than 2.5 appm. No such cracking was observed in helium-free control specimens or in specimens containing the lowest helium concentration. In addition to the HAZ cracking, brittle, centerline cracking occurred in the fusion zone of specimens containing 105 and 256 appm helium. Transmission and scanning electron microscopy results indicated that both the HAZ cracking and centerline cracking in the fusion zone resulted from the stress-induced growth and coalescence of cavities initiated at helium bubbles on interfaces. For the HAZ case, the cavity growth rate is modeled and shown to predict the experimentally measured 1-second time lag between peak weld temperature and the onset of cracking.

This study evaluated the effects of steroid inhalation on the deposition pattern of Tc-99m human serum albumin (Tc-99m HSA) radioaerosols in 25 asthma patients. A total of 12 normal controls also underwent the same examination. The pattern of radioaerosol deposition was quantitatively evaluated as the percentage of total deposition (PTD) in the central, intermediate, and peripheral regions of the right lung. The baseline PTD was calculated before and after the administration of a 1-week course of inhalation therapy of 0.05 mg beclomethasone dipropionate four times daily. There were significant differences in PTD between normal controls and asthma patients. Significant differences were also found before and after corticosteroid inhalation therapy in asthma patients. In conclusion, a week-long course of beclomethasone dipropionate inhalation therapy does influence the deposition patterns of aerosols in asthma patients, based on the findings of Tc-99m HSA radioaerosol inhalation lung scintigraphy.

This paper presents a new formulation for the laminar free convection from an arbitrarily inclined isothermal plate to fluids of any Prandtl number between 0.001 and infinity. A novel inclination parameter? is proposed such that all cases of the horizontal, inclined and vertical plates can be described by a single set of transformed equations. Moreover, the self-similar equations for the limiting cases of the horizontal and vertical plates are recovered from the transformed equations by setting?=0 and?=1, respectively. Heated upward-facing plates with positive and negative inclination angles are investigated. A very accurate correlation equation of the local Nusselt number is developed for arbitrary inclination angle and for 0.001 ?Pr ?8.

An analysis is developed for the laminar free convection from a vertical plate with uniformly distributed wall heat flux and a concentrated line thermal source embedded at the leading edge. We introduce a parameter?=(1 +QL/Qw)-1=(1 + RaL/Raw)-1 to describe the relative strength of the two thermal sources; and propose a unified buoyancy parameter?=(s RaL+s Raw)1/5 withs=1/(1 +Pr-1) to properly scale the dependent and independent variables. The variables are so defined that the resulting nonsimilar boundary-layer equations can describe exactly the buoyancy-induced flow from the dual sources with any relative strength to fluids of any Prandtl number from very small values to infinity. These nonsimilar equations are readily reducible to the self-similar equations of an adiabatic wall plume for?=0, and to those of free convection from uniform flux plate for?=1. Rigorous finite-difference solutions for fluids of Pr from 0.001 to 8 are obtained over the entire range of? from 0 to 1. The effects of both relative source strength and Prandtl number on the velocity profiles, temperature profiles, and the variations of wall temperature, are clearly illustrated.

A mixed convection parameter?=(sRa)1/4/(?Re)1/2, withs=Pr/(1+Pr) and?=Pr/(1 +Pr)1/2, is proposed to replace the conventional Richardson number, Gr/Re2, for combined forced and free convection flow on an isothermal vertical plate. This parameter can readily be reduced to the controlling parameters for the relative importance of the forced and the free convection,Ra1/4/(Re1/2Pr1/3) forPr » 1, and (RaPr)1/2/(RePr1/2 forPr « 1. Furthermore, new coordinates and dependent variables are properly defined in terms of?, so that the transformed nonsimilar boundary-layer equations give numerical solutions that are uniformly valid over the entire range of mixed convection intensity from forced convection limit to free convection limit for fluids of any Prandtl number from 0.001 to 10,000. The effects of mixed convection intensity and the Prandtl number on the velocity profiles, the temperature profiles, the wall friction, and the heat transfer rate are illustrated for both cases of buoyancy assisting and opposing flow conditions.

A method for extracting modal parameters of vibrating structures by using a vector autoregressive (ARV) time series model has been developed. The mathematical theory of a vector ARMA model, which includes a Green function matrix, a correlation function matrix and a spectral density matrix, is presented. The energy proportion index is a possible indicator for the damage detection. The mode shapes of the system are expressed in terms of transfer functions between measurement points. Finally, vibration data from a vertical cantilever beam, and from a sea trial of a new ship were processed by using the ARV model. The results show that this method can estimate model parameters from very short record lengths. Copyright 1993, 1999 Academic Press

The paper compares the unsteady airflow field in the conventional and the new dual-feed rotor spinning unit. A 3D finite volume computation (with optional turbulence model) is adopted to simulate the airflow dynamics with a focus on the rotor interior. The equations are solved using Fluent 14.5 package. The airflow results reveal that the second transfer channel effect is significant, particularly in the rotor interior. Visualization of iso-surfaces and velocity magnitude in the two reveal a striking difference in the internal flow patterns and turbulent strength. Comparison of the yarn properties spun on the two systems shows improved tenacity, elongation, and yarn evenness. A Small variation in yarn hairiness of the respective spun samples is observed.

Copper is the most widely used material in heat pipe manufacturing. Since the capability of wick structures inside a heat pipe will dominate its thermal performance, in this study, we introduce a hybrid surface modification method on the copper wire braids being inserted as wick structure into an ultra-thin heat pipe. The hybrid method is the combination of a chemical-oxidation-based method and a sol-gel method with nanoparticles being dip-coated onto the braid. The experimental data show that braids under hybrid treatment perform higher water rising speed than the oxidized braids while owning higher water net weight than those braids being only dip-coated with nanoparticle.

To investigate hydrodynamic performance of the end cover under different inclined angles, a series of 3-Dimensional geometric models of the end cover with different inclined angles were built by Creo. The maximum inclined angle is 32 degrees and the minimum is 6 degrees. Numerical simulations by solving the Navier-Stokes equation, coupled with the "k-e" turbulence model, were carried out. At last, regressive analysis method is used to deal with the result data. The data obtained by simulation were mainly analysed from three aspects. They are cause of the driving torque, drive efficiency and inclined angle of flow channel. The results show that the driving torque is formed mainly by the positive pressure of the water, and the influence of the viscous force on the driving torque of the rotor is negligible. What's more, both driving torque and pressure difference decrease with the increase of inclined angle in the form of power function. The driving efficiency increases in form of logarithmic function with the increase of inclined angle. This research has a great significance in the control of rotational speed of rotor and revealed the relationship between the driving torque of the rotor and the flow channel of the end cover.

The alveolar permeability (AP) in 21 patients with active diffuse infiltrative lung disease (ILD) was measured by 99Tcm-diethylenetriaminapentaacetate (DTPA) radioaerosol inhalation lung scintigraphy. The degree of AP damage in ILD was presented as the slope ( min-1) of the time-activity curve from the dynamic lung image. Meanwhile, the quantitative Ga lung scan (GA) was performed as a Ga uptake index (GUI) to evaluate the severity of lung inflammation in active ILD. The results show that no good correlation between the degree of AP damage and lung inflammation was found. When the patients were divided into two groups of (A) eight active ILD with normal chest X-ray (X-ray) and (B) 13 active ILD with abnormal X-ray, there was no significant difference between groups A and B for the DTPA and Ga results. In conclusion, the relationship between the degree of AP damage and lung inflammation in active ILD is not significant. This was not consistent with X-ray findings. There was, however, a significant difference between those with ILD and normal controls.

The severity of lung inflammation in 34 patients with systemic lupus erythematosus (SLE) was measured by quantitative 67Ga-citrate lung scanning. The severity of lung inflammation in SLE was represented by the 67Ga uptake index (GUI). Quantitative 67Ga lung scanning was also performed on 20 normal controls for comparison with the SLE patients. The patients were divided into two subgroups according to the following two criteria: (a) stable or flare stage according to clinical features; or (b) positive or negative results of chest X-ray. The GUI values of the subgroups were also compared. The results revealed a trend towards higher values of GUI in SLE patients than in the normal controls. The GUI values were also higher for SLE cases with a flare stage or a negative chest X-ray than in SLE cases with a stable stage or a positive chest X-ray. The statistical results reveal that the differences in the GUI values are not significant. However, we found that (1) positive chest X-ray findings may be a later manifestation of a lung inflammation and (2) the values of GUI parallel clinical features in SLE patients.