bluuebunny/crossref_metadata_2025 huggingface dataset:
Construction Failures in Lagos Metropolis: An insight of non-technical issues
Authors: Onwuanyi Ndubisi
Published: October 2016

The common causes of construction collapse are mainly design, materials, accidents, the elements, workmanship and supervision. Regarding the increasingly frequent incidents in the Lagos Metropolis, published findings of researchers have not been markedly different. This paper argues that beyond the technical issues already raised, there are important factors yet to be investigated, which may be classified as being non-technical in nature, but constitute hindrances not only to the capacity of the supervising agency, the Lagos State Building Control Agency to perform its functions, but more importantly, to the effective execution of building control generally. The study reviews earlier findings, the practice and challenges of building control in the Lagos Metropolis before identifying and discussing these other factors. The findings are that the building control function is inappropriately assigned to the state government, rather than the local governments, and that the state bureaucracy cannot effectively execute building control because of poor capacity and practices. The most important implication of this research is that, by drawing attention to issues which have hitherto been unconsidered, it brings to notice the need to ascertain pragmatically which tier of government is better suited to execute building control and offer the required capacity and organizational effectiveness.
ENERGY ANALYSIS OF WALL MATERIALS USING BUILDING INFORMATION MODELING (BIM) OF PUBLIC BUILDINGS IN THE TROPICAL CLIMATE COUNTRIES
Authors: Nobahar Sadeghifam Aidin , Marsono Abdul Kadir , Kiani Iman , Isikdag Umit , Bavafa Ali Asghar , Tabatabaee Sanaz
Published: October 2016

During the previous two decades, the energy saving potential using systematic building management is considered to be important which should be considered through the building lifecycle. Among the wide range types of different buildings, Public buildings are considered as one of the biggest energy-consuming sector in the world and major part of this amount is used by the air conditioning system especially in tropical climates. The most effective decisions related to sustainable design of a building facility are made in the feasibility and early design stages. Building Information Modeling (BIM) can expedite this process and provide the opportunity of testing and assessing different design alternatives and materials selection that may impact on energy performance of buildings. This paper aims at evaluating the efficiency of various types of wall materials with regard to theirs properties on energy saving. The case study in this paper is modeled by means of BIM application and then simulated by software, which is appropriate for energy analysis. The current energy consumption patterns of this case identified and shifted to the optimized level of energy usages by changing the walls materials to find most optimized of walls materials. Modification most optimized wall materials and energy analysis indicated 9347 Wh in Per meter square of electrical energy saving.
PRELIMINARY INVESTIGATIONS ON AN ENZYME IMMOBILIZED OPTICAL BIOSENSOR FOR ARSENITE DETECTION
Authors: Teoh Wei Kheng , Zahari Farhana , Shahir Shafinaz
Published: October 2016

Arsenite is an inorganic form of arsenic that poses hazardous effect to human. It is a common environmental heavy metal contaminant ubiquitously found in water and groundwater. In this study, an optical biosensor for arsenite determination was developed by immobilization of crude arsenite oxidase (Aio) extracted from recombinant E. coli, in chitosan solution coated on triacetyl-cellulose membrane employing DCPIP as colour indicator. The arsenite oxidase (Aio) was successfully expressed and extracted from recombinant E. coli strain BL21 (DE3). The protein concentration and specific activity of the crude arsenite oxidase were determined.  Expression of Aio was confirmed by SDS-PAGE. The crude Aio was also successfully immobilized in chitosan and coated on triacetyl cellulose membrane. The response time and dynamic range of the optical biosensor were optimized. The response time of the developed biosensor was 15 minutes. The amount of DCPIP reduced (DA) was inversely proportional to the arsenite concentration. Standard calibration curve for arsenite detection was achieved within the range of arsenite concentration from 25 µM to 200 µM. The maximum detection limit was determined to be 250 µM arsenite.
TWO NEW PRENYLATED CHALCONES FROM THE LEAVES OF ARTOCARPUS LOWII KING
Authors: Jamil Shajarahtunnur , Mohd Sirat Hasnah , Jantan Ibrahim
Published: October 2016

Two minor prenylated chalcones were isolated for the first time from the leaves of Artocarpus lowii King. These prenylated chalcones were identified as 2-hydroxyparatocarpin C (1) and 2¢,3,4¢,4-tetrahydroxy-3¢-prenylchalcone (2). The structures of these prenylated chalcone were elucidated by utilizing the data values obtained from 1H NMR, 13C NMR, DEPT, COSY, IR, UV and MS, as well as by comparison with literature values.
ATTRIBUTE SELECTION MODEL FOR OPTIMAL LOCAL SEARCH AND GLOBAL SEARCH
Authors: Basir Mohammad Aizat , Ahmad Faudziah
Published: October 2016

Attribute selection also known as feature selection is an essential process in data sets that comprise numerous numbers of input attributes. However, finding the optimal combination of algorithms for producing a good set of attributes has remained a challenging task. The aim of this paper is to find a list of an optimal combination search methods and reduction algorithm for attribute selection. The research process involves 2 phases: finding a list of an optimal combination search methods and reduction algorithm. The combination is known as model. Results are in terms of percentage of accuracy and number of selected attributes. Six (6) datasets were used for experiment. The final output is a list of optimal combination search methods and reduction algorithm. The experimental results conducted on public real dataset reveals that the model consistently shows the suitability to perform good classification task on the selected dataset. Significant improvement in accuracy and optimal number of attribute selection is achieved with a list of combination algorithms used.
PERFORMANCE OF A WATER PUMP IN AN AUTOMOTIVE ENGINE COOLING SYSTEM
Authors: Mohamed Tasuni Mohamad Lazim , Abdul Latiff Zulkarnain , Nasution Henry , Mohd Perang Mohd Rozi , Mohd Jamil Hishammudin , Misseri Mohd Nazri
Published: October 2016

A cooling system employed in an automobile is to maintain the desired coolant temperature thus ensuring for optimum engine operation. Forced convection obtained by means of a water pump will enhance the cooling effect. Thus it is necessary to understand the system’s pump operation and be able to provide for the ultimate cooling of the engine. The objective of this laboratory investigation is to study the water pump characteristics of an engine cooling system. The crucial water pump parameters are the head, power, and its efficiency. In order to investigate the water pump characteristic a dedicated automotive cooling simulator test rig was designed and developed. All of the data obtained are important towards designing for a more efficient water pump such as electric pump that is independent of the power from the engine. In addition to this fact, the simulator test rig can also be used to investigate for any other parameters and products such as radiator performance and electric pump before installation in the actual engine cooling system. From the experiment conducted to simulate for the performance of a cooling system of a Proton Wira (4G15), the maximum power equals to 37 W which indicates the efficiency of the pump is relatively too low as compared to the typical power consume by the pump from the engine which are about 1 to 2 kW. Whereas the maximum power and efficiency obtained from the simulator test rig simulator is equals to 42 W and 15% respectively.
DEVELOPMENT AND EVALUATION OF AN AUTOMOTIVE AIR-CONDITIONING TEST RIG
Authors: Amran Ahmad Zulkhairie , Abdul Latiff Zulkarnain , Nasution Henry , Mohd Perang Mohd Rozi , Mohd Jamil Hishammudin , Misseri Mohd Nazri
Published: October 2016

To evaluate an air-conditioning system performance on board is quite cumbersome and tedious process due to the limitation of space in the engine compartment. This paper presents the process of designing and the result from the automotive refrigeration system simulation that have been integrated into the test rig. To perform the test on automotive refrigeration simulator the location for the temperature measurement selected and thermocouples were installed. The locations of the temperature probes are at the inlet and outlet of compressor, condenser outlet and the inlet of the evaporator. The gas pressure was measured at low and high pressure sides located at evaporator outlet and receiver-drier respectively. The test results were analyzed using the properties table of the refrigerant used. The coefficient of performance (COP), cooling load of the system and compressor power consumption were determined. The variable parameters used are the evaporator blower speed and the air velocity passes through the condenser. The experimental results obtained show that increasing the blower speed will reduce the COP of the refrigeration system. The maximum COP of the system is 4.3 at the lowest evaporator blower speed. The power consumption will be reduced when the air flow velocity through the condenser is increased from 0, 40, 50, 60, 70 km/h respectively.
Konsep Akad Al-Ju’alah Di Dalam Perusahaan Multi-Level Marketing (MLM) Patuh Syariah
Authors: Tunggak Buerah , Tamjis Mohd Fairuz
Published: October 2016

Sales of products through the concept of Multi-Level Marketing (MLM) is a new form of business that is growing rapidly in Malaysia now. The business of the Malaysian population drastic response, including the Muslims. Nevertheless there are some aspects that often cause confusion and doubt in the business, especially in terms of adherence to Sharia. Among the aspects that need to be emphasized to ensure MLM companies operate on a Shariah platform is to examine the type of contract used. Each contract is recognized in Islamic Muamalat contains the pillars and the conditions that must be complied with. Violation of rules and conditions that have been set will cause the business carried invalid or void thereby making the non-compliant businesses. Between the concepts of contracts in the MLM business that need attention is the relationship between MLM companies and distributors (members), distributors (members) and the buyer, pegedar old (upline) and distributors (downline), salaries, bonuses and setting membership fees. In general, the application includes several types of MLM business like a business contract of al-Bai‘ (sale), al-Wakalah (business representative), al-Ijarah (leasing) and al-Ju‘alah (promise of wages). Writing is only focusing on the concept of al-Ju‘alah contract that is embedded in the MLM business. This article will detail the pillars and conditions that must be adhered to by all parties involved in the contract of al-Ju‘alah. This article will also try to identify common violations committed by MLM companies on the pillars and conditions of the contract. Finally, this paper suggests the parties involved in an MLM company in the country to implement the concept of MLM business through the application of Shariah tenets and conditions of the contract which will be explained later. All parties need to be involved to ensure that business is conducted so that the provision of Shariah-compliant obtained lawful and blessed. Keywords: Multi-Level Marketing (MLM), Transactions, Akad al-Ju‘alah, Shariah-compliant.
Kajian Kes Simtom Fizikal Histeria Rasukan Jin di Malaysia
Authors: Rafiq Ezwan , Junoh Husin , Nizar Tamar Jaya , Md. Jidi Kamarolzaman
Published: October 2016

This study aims to elaborate symptom of hysteria in Malaysia more specifically. Through this study, interview and observation carried out towards hysteria patients that are under evil possession, patient’s family and ruqyah healer to determine these physical symtomps represent the disease. The result of qualitative study is analysed using Atlas ti 7 software and shown hysteria symptom under evil possession is proved as same as what had written in al-Quran and al-Sunnah. Meanwhile, there are additional symtomps being gain from Islamic Scholar’s writing, therapists and patients experiences. Other than that, physical symptom of hysteria under evil possession remains mysteriousas the sense of pain keep changing in every part of body. The cause of pain also could not been traced under allopathy treatment. The symptom shown when ruqyah treatment started and slowly fade away after the ruqyah treatment done. There are mixture between symptom of hysteria under normal possession or al-Sar’ or al-Mass with witchcraft hysteria.
EPISTEMOLOGI PRAKTIK BAHAN BANTU MENGAJAR NABAWI DALAM PENGAJARAN DAN PEMBELAJARAN
Authors: Wan Harun Mohammad Amir , Ruskam Aminuddin , Baharuddin Ahmad Syukran , Othman Rashidah , Abdul Sarip Mohd Ariff
Published: October 2016

The application of Teaching Aids (TA) is closely related to the success of teaching and learning process. This article discusses the Nabawi TA that had been practiced by Rasulullah p.b.u.h. to educate his companions r.a. until they became outstanding persons. The discussion concluded that Nabawi TA could be categorized to three sections; (a) TA from surrounding objects, which includes sketch and physical objects. (b) Teacher itself as TA, which includes teacher’s solitariness as TA, teacher with other parties as TA and teacher’s body parts as TA. (c) Students themselves as TA, which include student’s solitariness as TA, imaginations as TA and student's body parts as TA. In conclusion, Nabawi TA should be recommended as a support for teachers to increase TA application level in schools.
ANALISIS LITERATUR ISU PELANTIKAN HAKIM SYARIE WANITA DI MALAYSIA
Authors: Nasohah Zaini , Majemi Fatimah , Mohd Kusrin Zuliza , Muhammad Husni Ahmad , Samuri Mohd Al-Adib
Published: October 2016

Qadi or judge is a significant post in a state. Islam has enumerated certain detailed and strict conditions for a person to be appointed as a judge. Among the conditions is appointing a male judge for the post. Discussion on this issue in Malaysia is still ongoing as there are states that have not giving opportunity for women to have the post.  This article aims to analyze literature review on the issue in Malaysia. A comparative content analysis approach was applied in analyzing the data gathered.  The analysis discovers that there are lot of writings in fiqh references that disagree with the appointment of female judges. However, contemporary writings show that a lot of writing that supported and agreed with the appointment of female judges in certain area of judgements.Keywords: Shariah Judges, Women, Justification, Appointment, Acceptance
Examining Learning and Peer Efficacy Among Secondary School Students In District of Ledang
Authors: Md. Sawari Siti Salwa , Ghazali Mohd Al'Ikhsan , Trayek Fuad A. A. , Awang Mat Muhamad Zahiri
Published: October 2016

Efficacy functions to enhance the desire of learning through mediations of motivations and confidence. The present study is designed to achieve two main objectives. First, to identify the level of learning efficacy of public and religious secondary school students. Second, to examine the significant difference level of learning efficacy between public and religious school students. This study involved 242 students sampled from four schools in district Ledang. The sampled participated in the survey, employing a twelfth item questionnaire measuring  Learning Self-efficacy (LSE) and Peer Self-efficacy (PSE).  The data are analysed quantitatively using descriptive statistics and independent-samples t-tests. The result showed that the majority of students experience a moderate level of learning efficacy. Generally, for the selected public school students the mean is 2.75 and religious school students the mean is 2.97. Regarding the comparison level of learning efficacy between the two types of students, the findings of the current study show that there is no significant differences (p=.47), while peers self-efficacy revealed that there are significant differences (p=0.001).
Sifat Keperibadian Guru Pendidikan Islam (GPI) Terhadap Rakan Setugas Dan Pihak Atasan Di Sekolah: Satu Kajian Kes
Authors: Hamdan Nazirah , Jasmi Kamarul Azmi
Published: October 2016

This article discussed the Personality Traits of Islamic Education teacher (GPI) towards fellow colleagues and school top management. This study involved several secondary schools in the State of Johor. Interviews, observations, and analysis of documents were used as a data collector instruments. All data were then arranged by using N'Vivo software version 7.0 in order to produce themes, sub-themes and schedule matrix associated with the GPI personality traits towards fellow colleagues and top management. Results of the study indicated twenty one (21) traits that can be established as a pattern and they are committed; compliance; positive thinking; well mannered; respectful; easy going; concerned; have elements of humor; responsible; a role model; sensitive; understanding; tolerance; friendly; diligent; cooperative; approachable; as a point of reference; and unprejudiced. While the other nine (9) traits cannot be established a pattern. Therefore, this study has produced a commendable Personality Traits of Islamic Education teacher (GPI) with Fellow Colleagues and School Top Management Model.Keywords: Personality Traits, Islamic Education teacher, Model of Islamic Education Teacher personality against fellow colleagues and top management.
Ramification conjecture and Hirzebruch’s property of line arrangements
Authors: Panov D. , Petrunin A.
Published: October 2016

The ramification of a polyhedral space is defined as the metric completion of the universal cover of its regular locus. We consider mainly polyhedral spaces of two origins: quotients of Euclidean space by a discrete group of isometries and polyhedral metrics on $\mathbb{C}\text{P}^{2}$ with singularities at a collection of complex lines. In the former case we conjecture that quotient spaces always have a $\text{CAT}[0]$ ramification and prove this in several cases. In the latter case we prove that the ramification is $\text{CAT}[0]$ if the metric on $\mathbb{C}\text{P}^{2}$ is non-negatively curved. We deduce that complex line arrangements in $\mathbb{C}\text{P}^{2}$ studied by Hirzebruch have aspherical complement.
Passive System Reliability Modeling of the Combination of Failure Modes
Authors: Burgazzi Luciano
Published: October 2016

Innovative probabilistic models to extend the reliability analysis of passive systems under different modes of failure are proposed.

The prevailing failure mode on the system can be predicted through the failure probability assessment on each specific mode. A realistic case is presented to analyze a passive system with two kinds of major failure modes — natural circulation stoppage due to e.g., isolation valve closure (a catastrophic failure) and heat transfer process degradation due to e.g., deposit thickness on component surfaces (a degradation failure). Modeling of each individual failure mode together with system reliability analysis is presented and results are discussed.
Simulation Study of Dynamic Characteristic of Once-Through Steam Generator for CEFR
Authors: Shangshang Ye , Hongyi Yang , Xiaokun Wang
Published: October 2016

The reliability of steam generator is extremely important for the sodium-cooled fast reactor nuclear power plant safety and stable operation. The convective heat transfer mechanism of the once-through steam generator (OTSG) of China Experimental Fast Reactor (CEFR) was researched. The water/steam side was divided into four areas according to the heat flux and steam quality, named subcooled, nucleate-boiling, film-boiling, and superheater. In order to accurate determine the DNB, the CHF table was used in this paper. Based on the homogeneous flow model and fixed boundary method, a thermal-hydraulic simulation system, which named OTAC, was established in this paper. To evaluate its performance, the predictions of this method were compared with PSM-W code. The maximum difference between the temperatures predicted by this model and PSM-W was ∼5K. The calculated results are consistent with the actual experiment data, which indicates the correctness of the mathematical model and simulation method. Static and dynamic characteristic researches of CEFR OTSG have done in the simulation system. And the system can be used to simulate the OTSG dynamic in real-time.
Thermal-Hydraulic Analysis of a Passive Containment Cooling System Using Dynamic Liquid Film Model in CFD Code GASFLOW-MPI
Authors: Xiao Jianjun , Travis John R. , Bottoni Maurizio
Published: October 2016

Falling water film modeling is crucial for the thermal hydraulic analysis of passive containment cooling system in advanced light water reactors. A dynamic liquid film model has been developed in the 3-D parallel CFD code GASFLOW-MPI to track the water film transport over the external surface of the steel containment. The gas phase, both inside and outside of the containment, the steel containment and the falling water film are coupled with each other through the essential source terms of inter-phase transport. The model has been verified by the Nusselt solution. Since very few useful experimental data can be found in the open literature, we compared the numerical results of GASFLOW-MPI and COMMIX code which is considered to be reliable because the code has been validated by the experimental data of the Westinghouse small/large scale integral test facilities. A passive containment cooling system has been simulated using the dynamic film model in GASFLOW-MPI. Good agreement was obtained when compared to the COMMIX results, regarding the water film thickness, velocity and temperature. The effect of mesh sensitivity on the heat and mass transfer needs further study. Further work is required concerning the heat transfer, evaporation and boiling at the interface of water film and gas mixtures in the annular space. Local film dry-out model will be implemented in the GASFLOW-MPI. In general, the calculation results using the dynamic film model positively demonstrated the capability of CFD code GASFLOW-MPI in simulation of passive containment cooling system.
Preliminary Study of Function Determination and Capacity of ACP600’s Reactor Emergency Borating System
Authors: Zhang Shu , Zhang Xiaohua
Published: October 2016

ACP600 is a 600WMe power, self-reliance developed pressurized water reactor design of third generation technology, which is the China National Nuclear Corporation’s (CNNC) achievement of continuous R&D and engineering feedback started with M310 series and 600WMe designs. In general technical project of ACP600, there is a plan to cancel Boron Injection Tank (BIT) in safety injection system and set Reactor Emergency Borating (REB) system in order to enhance safety of nuclear power plant. This paper discusses function determination and system capacity of ACP600’s REB system based on the investigations of both international and domestic advanced third generation nuclear power plant emergency borating system’s safety functions and according to ACP600’s top design and general project along with operation and typical accident analysis, bringing forward to preliminary suggestions about function determination and system capacity of ACP600’s REB system as well as further aspect and content for investigations. This provides concrete information for further design of ACP600’s REB system.
Behavior of Clusters on Smooth and Nano-Structured Surfaces
Authors: Yan Xiao , Chen Feng , Huang Zhiyong , Bo Hanliang
Published: October 2016

Nano-structured surfaces are showing great potential for the promotion of dropwise condensation. When applied as the condensing surfaces in the containment and condenser, it is promising that both the safety and economy of the nuclear power plant will be significantly enhanced. However, the behavior of nano-droplets on surfaces remains to be clarified. As a result, the design or manufacture of nano-structures lack sufficient theoretical instructions. In this work, migration and size distribution of nano-droplets are comparatively studied on smooth and nano-structured surfaces by molecular dynamics simulations. It was found that the migration of an individual nano-droplet on the walls resembles a random walking process, and the migration scope is about 0.5 to 10 times the droplet size; while on the nano-pillared surfaces, migration and coalescence of nano-droplets are limited by the structures, therefore, a larger number of small droplets exist on the surfaces with densely arranged nano-structures.
Experimental Study on Splashing During Liquid Jet Impingement Onto a Liquid Film
Authors: Yi Zhan , Oya Naoki , Enoki Koji , Okawa Tomio , Ohno Shuji , Aoyagi Mitsuhiro
Published: October 2016

A liquid jet is of considerable importance in many industrial fields including jet cleaning, jet engine and combustion. As an important example, the Monju nuclear power plant in Japan experienced a sodium leak in 1995. This led to a fire accident because the sodium reacted with oxygen in the air. To predict the significance of the fire accident, accurate evaluation of the amount of splashed droplets caused by the sodium jet impingement is of great importance. In this work, the relationship between the condition of a liquid jet and the amount of splashed droplets is explored experimentally. In the experiments, a liquid jet was emanated vertically downward from a circular nozzle onto a liquid film formed on a horizontal plate. Visualization using a high speed camera was performed to observe the condition of the liquid jet. From the nozzle, the mode of the liquid jet changed jet, lump and drop. Here, the jet mode means the continuous jet with smooth surface, the lump mode the continuous jet with disturbed surface and the drop mode the broken jet. Dependences of the transition length to each mode on the important parameters such as the jet velocity and the nozzle diameter were investigated. Measurement was also conducted for the splash ratio that is defined as the ratio of the amount of splashed droplets to the jet flow rate. It was found that the splash ratio is high when the liquid jet is in the drop mode at the impact point. It was shown that the splash ratio can be correlated well as a function of the impact Weber number and the Strouhal number of the droplets impinging the liquid film.
Comparative Study of Coated Particle Stresses With Different Coating Layer Performance
Authors: Li Rong , Liu Bing , Tang Chunhe
Published: October 2016

Tristructural-isotropic coated fuel particle is an important fuel design for high-temperature gas-cooled reactor. Irradiation-induced pyrocarbon (PyC) shrinkage and creep behavior will affect greatly the stresses of a TRISO-coated particle. In this study, 5 cases under different conditions by analytical solution were studied to calculate the particle stresses with different fuel behavior. These cases varied in particle geometries, the mount of gas pressure or fuel behavior. A comparison between the results and other benchmarking studies among different codes was made. The results indicated that the calculated results in this study were in good agreement with other codes.
Lattice Boltzmann Method for Solving Time-Dependent Radiation Transport and Reactor Criticality Problems
Authors: Gairola A. , Bindra Hitesh , Agarwal Gaurav , Singh Suneet
Published: October 2016

The recently developed lattice Boltzmann equation (LBE) framework [1] for radiation transport is extended to solve time-dependent nonequilibrium neutron transport problems. Dynamics of radiation and material energy exchange is modeled by coupling the radiation transport equation with the material energy equation in a one-dimensional isotropically scattering homogenous medium. The LBE equations are obtained for corresponding radiative or neutron transport in constant source and reactor criticality search problems. Furthermore, a two-dimensional D2Q8 & D2Q16 LBEs are proposed for solving the time-dependent neutron transport equation in a heterogenous media (e.g., a checkerboard lattice with pure scattering and absorbing cells). The results obtained with LBE are in good agreement with the existing discrete ordinate method results for the benchmark problem.
Design of Control Systems for Accelerator Driven Sub-Critical System
Authors: He Zhiyong , Cui Wenjuan , Zhao Qiang , He Yichuan , Luo Yuxi
Published: October 2016

An accelerator driven sub-critical (ADS) system consists of an accelerator, a sub-critical reactor, and a spallation target located at the centre of the reactor core. In this paper, we report the conceptual design of the control system for ADS system, which will integrate two big nuclear facilities, an accelerator and a reactor, into an overall system for the first time in the world. Because varied expectations on redundancy, diversity, availability, reliability, communication speed and latency are required for both accelerator and reactor, at least six systems have been designed for an ADS system, i.e. a main control system, three protection systems, a timing system, and a data archiving system. The main control system is designed to monitor and control the overall ADS system. In order to exactly couple the high-energy beam from the accelerator to the spallation target located in the reactor, many instrumentations are required in the main control system, such as instrumentations for beam monitoring and beam switching-off, instrumentations for ex-core neutron monitoring, instrumentations for in-core temperature and neutron monitoring, instrumentations for monitoring and controlling several cooling loops, and Instrumentations for control rod system. In order to enhance the safety of the ADS system during the operation, three protection systems, a reactor protection system, an accelerator’s machine protection system and a personnel protection system, have been designed. Independent network is used for each system. Furthermore, both redundant network and hardwired communication are used in each protection system to provide extremely reliable communication link. Finally, the communication network with parallel redundancy protocol has been studied for the main control system. In comparison with a network without redundancy, the parallel redundancy protocol can improve dramatically the reliability of a communication network by up to forty thousand times.
Improving RIMPUFF Prediction Using CALMET Diagnostic Meteorological Model
Authors: Liu Yun , Fang Sheng , Sun Sida , Li Hong
Published: October 2016

The Risø Mesoscale PUFF model (RIMPUFF) predicts dispersion of released hazardous material and plays an important role in the emergency response system of many Chinese nuclear power plants (NPPs). The wind field over the calculation domain is a critical input of RIMPUFF, which dominates the performance of RIMPUFF. Due to the complex topography of most Chinese NPP sites, it remains challenging to provide a refined wind field for RIMPUFF prediction. To solve the problem, California Meteorological Model (CALMET) is coupled with RIMPUFF for wind field calculation in this study. Moreover, the computing scope and capability of RIMPUFF are enhanced in order to obtain more accurate prediction for the emergency response and source term inversion in nuclear accidents. Except for that the unlimited amount of grid with higher resolution is supported, a new sampling module is added to RIMPUFF for predicting the concentration of radioactive materials and dose at number-unbound arbitrary location. To verify the CALMET-RIMPUFF method, a wind tunnel experiment that replicates the topography of one Chinese NPP site within 10 km-range, is conducted. In the experiment scenario, the speed and vertical profile of the incoming flow is carefully set according to the annual mean wind speed and wind profile data measured in recent years on the meteorological tower of this NPP. The results demonstrate that the wind field calculated by CALMET is consistent with the topography. With this wind field, the RIMPUFF-predicted concentration distribution matches the measurements well both qualitatively and quantitatively. Moreover, the calculation of U.S. Environmental Protection Agency (EPA) statistical evaluation metrics indicate that the random scatter is within a factor of 1.8 and the FAC2 is nearly 80%. It proves the acceptability of CALMET-RIMPUFF over the complex topography of Chinese NPP sites.
Massively Parallelized Simulation of Deflagration-to-Detonation Transition in a Konvoi-Type Pressurized Water Reactor
Authors: Hasslberger Josef , Katzy Peter , Sattelmayer Thomas , Boeck Lorenz R.
Published: October 2016

For the purpose of nuclear safety analysis, a reactive flow solver has been developed to determine the hazard potential of large-scale hydrogen explosions. Without using empirical transition criteria, the whole combustion process (including DDT) is computed within a single solver framework. In this paper, we present massively parallelized three-dimensional explosion simulations in a full-scale pressurized water reactor of the Konvoi type. Several generic DDT scenarios in globally lean hydrogen-air mixtures are examined to assess the importance of different input parameters. It is demonstrated that the explosion process is highly sensitive to mixture composition, ignition location and thermodynamic initial conditions. Pressure loads on the confining structure show a profoundly dynamic behavior depending on the position in the containment.
Mathematical Models of Spacer Grids
Authors: Maskal Alan B. , Aydogan Fatih
Published: October 2016

The fuel rods in Pressurized Water Reactor (PWR) and Boiling Water Reactor (BWR) cores are supported by spacer grids. Even though spacer grids add to the pressure loss in the reactor core, spacer grids have several benefits in Light Water Reactors (LWRs). Some of these benefits are: (i) increasing the turbulence at the bottom of the reactor core for better heat transfer in single phase region of the LWRs, (ii) improving the departure nucleate boiling ratio results for PWRs, and (iii) improving critical power ratio (CPR) values by increasing the thickness of film in annular flow regime in the top section of the reactor core of BWRs. Several mathematical models have been developed for single and two phase pressure loss across the grid spacer. Almost all of them significantly depend on Reynolds Number. Spacer designs have evolved (incorporating mixing vanes, springs, dimples, etc), resulting in the complexity of the analysis across the grid, all the models have been compared not only theoretically but also quantitatively. For the quantitative comparisons, this work compares the results of mathematical spacer models with experimental data of BWR Full Size Fine Mesh Bundle Tests (BFBT). The experimental data of BFBT provides very detailed experimental results for pressure drop by using several different boundary condition and detailed pressure drop measurements. Since one CT-scanner was used at the bundle exit and three X-ray densitometers were used for the chordal average void distribution at different elevations to generate the BFBT results, detailed two phase parameters have been measured in BFBT database. Two bundle types of BFBT, the current 8×8 type and the high burn-up 8×8 type, were simulated. Three combinations of radial and axial power shapes were tested: 1) beginning of cycle (BOC) radial power pattern/cosine axial power shape (the C2A pattern); 2) end of cycle (EOC) radial power pattern/cosine axial power shape (C2B pattern); and 3) beginning of cycle radial power pattern/inlet peaked axial power shape (C3 pattern) in BFBT. The pressure drop in BFBT database was measured in both single-phase flow and two-phase flow conditions that cover the normal operational behavior. BFBT database gives the three combinations of high burnup assemblies with different radial and axial power shapes, namely C2A, C2B and C3, which were utilized in the critical power measurements. There are two types of spacers in this program — ferrule type and grid type. Therefore, detailed experimental data of BFBT was used for analyzing mathematical models of spacer grid for various boundary conditions of BWR in this paper. It was observed and discussed that pressure drop values due to spacer models can be significantly different.
Comparison of Fukushima Response in the United States and Europe
Authors: Lutz Robert J. , Prior Robert P.
Published: October 2016

The accident at the three reactor units at Fukushima Daiichi showed weaknesses in the plant coping capability for beyond design basis accidents caused by extreme external events. The weaknesses included plant design features, accident management procedures and guidance, and offsite emergency response. As a result, significant changes to plant coping capability have been made to light water reactors worldwide to enhance the coping capabilities for beyond design basis accidents. However, the response in the United States has been significantly different from that in Europe in a number of ways. In the United States, the regulator and the industry convened separate expert panels to review the Fukushima accident and make recommendations for enhancements. On the regulatory side, a series of three Orders were issued and that required the implementation of certain enhancements (Mitigation strategies, hardened vents for certain BWRs, spent fuel pool level indication) to ensure adequate protection for the health and safety of the public. Other enhancements were subject to the “Backfit Rule” which requires that changes to regulatory requirements be shown to be cost beneficial using accepted methodologies. Simultaneously, the industry took independent steps to develop a diverse and flexible coping strategies (known as FLEX) and other enhancements. The focus in the United States was clearly on enhancements to guarantee continued core, containment and spent fuel pool cooling in the event of beyond design basis accidents, particularly those resulting from extreme external events.

In Europe, the regulatory agencies ordered the development and completion of “Stress Tests” for each reactor site. These Stress Tests were focused on identifying the capability of the plant and its staff to respond to increasingly severe external events. The Stress Tests not only examined the ability to maintain core, containment and spent fuel pool cooling but also the ability to mitigate the consequences of accidents that progress to core damage (i.e., a severe accident). Regulatory requirements were then issued by the national regulators that addressed the weaknesses identified from the Stress Tests. While many of the enhancements to the plant coping capability were similar to those in the United States, significant hardware enhancements were also required to reduce the consequences of core damage accidents including hydrogen control and containment filtered venting.

Finally, most European regulators also include severe accident management guidance (SAMG) as a regulatory requirement. In the United States, SAMG will be maintained as a voluntary industry commitment that is subject to regulatory oversight review.
Instrument Health Monitoring for Extending Calibration Intervals of Safety Related Instruments
Authors: Black R. Steven , Hussey Aaron J. , Bickford Randall L.
Published: October 2016

The ability to extend calibration intervals for nuclear plant instrumentation has multiple benefits for improving productivity and reducing operating costs at nuclear plants. Benefits include fewer calibrations inside containment during an outage and associated reduced critical path time and ALARA exposure, reduced risk of calibration error or instrument damage during removal and replacement, and reduced operations and maintenance cost for instrument removal, calibration and replacement.

A good instrument calibration program ensures instruments are checked frequently enough to provide a high level of confidence that they are performing within acceptable limits, but no more frequently. Over-testing of plant instruments and equipment should be avoided for two reasons: valuable resources are expended on maintenance that might not measurably improve plant safety, reliability, or efficiency; and the potential exists for adjustment errors or equipment damage each time an instrument is removed from service for testing. Over-testing increases the risk of errors or damage being introduced without a justifiable improvement in reliability.

This paper discusses the regulatory framework for extending calibration intervals of safety related instruments for U.S. based nuclear power plants. Necessary changes to licensing, plant processes and procedures, training, and configuration management are summarized. An example application of pattern recognition modeling is provided to highlight the analytical support for the processes provided by active monitoring to confirm on-going instrument heath. The paper concludes with a listing of recommended steps to implement a practical program for extending calibration intervals of safety related instruments within the U.S. nuclear regulatory environment.
First-Principle Studies of Source Term Analysis in HTR-PM: From Framework to Preliminary Result
Authors: Fang Chao , Li Chuan
Published: October 2016

High Temperature Reactor-Pebblebed Modules (HTR-PM) is a typical high-temperature gas cooled reactor (HTGR) [1]. In the HTR-PM, helium is used as the coolant to the primary circuit and the fission products released from fuel elements would be carried into circulation by helium [2]. When analyzing the source terms in HTR-PM, it is important and necessary to know the amount of nuclides adsorbed on the component materials of primary circuit [3] and furthermore, the detail mechanism of adsorption is also essential, which could not be obtained from traditional phenomenological analysis and conservative estimation. In order to solve this challenge, we established a framework with ab-initio methods. In this paper, the detail theory of ab-initio theory and the actual usage in the calculation of the adsorption energy, Fermi level, density of state and charge density difference are given firstly. And then, we show the calculated results of adsorption behaviors of radioactive fission products (Cs, Sr, Ag, I) on 2•1/4Cr1Mo and SiC, which are important structural materials for steam generator and coated particle of fuel elements for HTR-PM, respectively. It is found that Ag and I atoms prefer to be adsorbed at the square hollow site of the face-centered cubic iron cell with binding energy of about 1eV and 3eV respectively. By contrast, Cs and Sr atoms are not adsorbed on the surface of 2•1/4Cr1Mo. For the study of adsorption on SiC, it shows that all the four nuclides can be adsorbed on the surface of SiC with the binding energy of about 1∼3 eV. Finally, the adsorption rates of these nuclides are estimated by using the first-principle calculation results of adsorption energy. The adsorption rate can be used to determine the amount of adsorbed radioactive nuclides for nuclear safety evaluation of HTR-PM. These results can illustrate the micro pictures of the interaction of fission products and material, which is a new and useful way to analyze the source term in physical level.
Nuclear Air Cleaning Codes and Standards Development and Use in the United States
Authors: Bellamy Ronald R.
Published: October 2016

The need to provide standardized guidance for the use of air cleaning systems in nuclear facilities was recognized in the 1960’s when plans for nuclear facilities were at their peak. The American National Standards Institute (ANSI) asked a group of experts to generate documents for boiling-water-reactor standby gas treatment systems for accident mitigation. These experts immediately recognized that their scope needed expansion to include all air cleaning safety systems at all types of nuclear facilities. Their efforts resulted in the issuance of documents that provided guidance for the components in air cleaning systems (ANSI N509), and guidance for the testing of these systems (ANSI N510). Subsequently, it was recognized that this guidance needed to be formalized and implemented in a code format, with requirements instead of recommendations. Various other organizations were also providing guidance in different forms. The US government (the Nuclear Regulatory Commission) issued regulatory guides, and the American Society for Testing of Materials (ASTM) issued many documents providing specifications for activated carbon used in air cleaning systems for radioiodine removal. Acknowledging the need to consolidate all of these documents in a single source, the American Society for Mechanical Engineers (ASME) requested the air cleaning experts to work on publishing a code section under ASME auspices. This code section, designated AG-1, was assigned to a newly formed committee, the ASME Committee on Nuclear Air and Gas Treatment (CONAGT). This Committee started work in the mid 1970’s, and has issued various sections of the code since then, and the document now totals 600 pages. This code section covers the design, construction, installation, operation and testing of air cleaning systems in nuclear facilities. Work continues on updates to these sections of the AG-1 Code, as well as new sections specifically addressing gas processing systems. ASME code section AG-1 is the main international document for nuclear air cleaning systems for safe operation of nuclear power facilities, to ensure the safety of workers, and to protect public health and safety and the environment. The Code has four divisions, and a membership of over 100 of the premier air cleaning experts from 11 different countries.
Transient Analysis on Helium Coolant Tube Break Accident of Dual-Functional Lithium Lead Test Blanket Module
Authors: Sun Qian , Peng Tianji , Zhou Zhiwei , Chen Zhibin , Jiang Jieqiong
Published: October 2016

Dual-functional Lithium Lead Test Blanket Module (DFLL-TBM) was proposed by China for testing in the International Thermonuclear Experimental Reactor (ITER).When an in-TBM helium coolant tube breaks, high pressure helium will discharge into the Pb-Li breeding zones. The pressure shock in the TBM will threaten the structural integrity and safety of ITER. Simulation and analysis on helium coolant tube break accident of DFLL-TBM was performed, and two cases with different break sizes were considered. Computational results indicate that intense pressure waves spread quickly from the break to the surrounding structures and the variation of pressure in the TBM breeding box is drastic especially when the pressure wave propagation encounters large resistance such as at the bending corner of the flow channel, the inlet and outlet of Pb-Li, etc. The maximum pressure in the TBM breeding box which is even higher than the operating pressure of helium also occurs in these zones. Although the pressure shock lasts for a very short time, its effect on the structural integrity of DFLL-TBM needs to be paid attention to.