Auxiliary Building Research Articles

Seismic Response Analysis of Nuclear Power Plant Structures and Equipment due to the Pohang Earthquake

The probabilistic seismic safety assessment is one of the methodology to evaluate the seismic safety of the nuclear power plants. The site characteristics of the nuclear power plant should be reflected when evaluating the seismic safety of the nuclear power plant. The Korea seismic characteristics are strong in high frequency region and may be different from NRC Regulatory Guide 1.60, which is the design spectrum of nuclear power plants. In this study, seismic response of a nuclear power plant structure by Pohang earthquake (2017.11.15. (KST)) is investigated. The Pohang earthquake measured at the Cheongsong seismic observation station (CHS) is scaled to the peak ground acceleration (PGA) of 0.2 g and the seismic acceleration time history curve corresponding to the design spectrum is created. A nuclear power plant of the containment building and the auxiliary buildings are modeled using OPENSEES to analyze the seismic response of the Pohang earthquake. The seismic behavior of the nuclear power plant due to the Pohang earthquake is investigated. And the seismic performances of the equipment of a nuclear power plant are evaluated by the HCLPF. As a result, the seismic safety evaluation of nuclear power plants should be evaluated based on site-specific characteristics of nuclear power plants.

Study on Post-Fire Safe Shutdown Analysis using an Imaginary Plant for Training

본 연구에서는 다중오동작을 포함하고 있는 화재안전정지분석 교육자료를 개발하기 위하여 가상원전에서의 화재안전정지분석을 결정론적 화재분석코드를 사용하여 수행하였다. 교육용 가상원전은 원자로건물과 보조건물로 이루어졌고, 총 22개의 방화지역으로 구성되었다. 교육용 가상원전의 각 방화지역에는 밸브, 펌프, 비상디젤발전기, 스위치기어, 모터제어반, 로직컨트롤러 등의 기기가 배치되었다. 교육용 가상원전 기기들은 두 개의 케이블로 연결되었으며, 각 케이블은 케이블 트레이를 따라서 방화지역을 지나간다고 가정했다. 방화지역분석을 위해 교육용 가상원전에 대한 기기 및 케이블 정보를 데이터베이스화하였고, 다중오동작 시나리오, 기기로직 및 케이블로직을 가정하여방화지역분석을 수행하였다. 방화지역 분석결과 문제가 되는 케이블과 케이블 트레이에 대해서 3시간 내화성능으로 케이블을 래핑하는 완화조치를 적용하였다.In this study, a post-fire safe shutdown analysis (PFSSA) including multiple spurious operation (MSO) treatments for cables was conducted with an imaginary nuclear power plant for training using a deterministic fire analysis code. The imaginary nuclear power plant for the training consisted of a reactor containment building and an auxiliary building, including a total of 22 fire areas. The equipment including valves, pumps, emergency diesel generators, switch gears, motor control centers, and logic controllers were located in each fire area of the imaginary plant. It was assumed that each equipment is connected with two cables and that each cable passes through the fire areas along the cable trays. A database containing the information on the equipment and cables for the imaginary plant was constructed for the fire area analysis. The fire area analysis was performed for several assumed MSO scenarios, equipment logics, and cable logics. A mitigation measure using a three hour rated wrap was applied to the failed cables and cable trays after the fire area analysis.

SMART 2013: Lessons learned from the international benchmark about the seismic margin assessment of nuclear RC buildings

In this paper, the main findings and conclusions drawn from the second international benchmark named SMART 2013 and jointly organized by the French Sustainable Energies and Atomic Energy Commission (CEA) and Electricité De France (EDF) within the framework of a wide research program entitled “Seismic design and best-estimate Methods Assessment for Reinforced concrete buildings subjected to Torsion and nonlinear effects” (SMART) are presented. A 1:4-scaled reinforced concrete (RC) specimen, representing a part of a nuclear auxiliary building and designed according to French guidelines for a PGA level equal to 0.2 g, was subjected to shaking table tests; results of this experimental campaign are used as reference data for this benchmark. The input ground motions considered in the seismic loading sequence are mainly natural bi-axial signals (main shock and aftershock) recorded during the Northridge earthquake that took place in California, USA in 1994 and have a PGA (Peak Ground Acceleration) about 1.8 g. These high-intensity seismic loadings allow assessing the relevancy of nonlinear numerical models when they have to deal with strong nonlinearities due to concrete cracking. The results produced by the 42 teams which participated in the international benchmark show that (i) the dynamic behavior of the specimen is well captured when dealing with the design level, (ii) the displacement are underestimated when dealing with the beyond design behavior, (iii) the peak frequency shifts are well captured and (iv) the damaging effect of the Northridge aftershock is almost null. Last, seismic safety margins of the specimen are quantified by two mechanical indicators; the results confirm the fact that the RC specimen which was designed according to the codes applicable in the French nuclear industry, exhibits noticeable good performance level regarding collapse prevention.

The last occupation of Asine in Argolis

Kastraki Hill on the eastern Argolic Gulf, with visible remains of impressive fortifications, has been identified since the mid-19th century as the position occupied by the acropolis of ancient Asine. The first systematic excavations were carried out by the Swedish Institute in the 1920s and revealed the continuous habitation of the site from the Early Helladic period (3rd millennium BC) up to the late 4th-early 5th century AD. Many additions and repairs on the acropolis were made during the Byzantine period and the 2nd Venetian Occupation of the Peloponnese (1686–1715). However, the most destructive interventions in the area are the works carried out by the Italians during World War II. Fearing an invasion of the Allies on this side of the Peloponnese, the Italians fortified the acropolis by making additions to the ancient walls and constructing auxiliary buildings, pillboxes, observation posts and trenches around the rocky outcrop using materials from buildings of the Lower Town. Their departure after the war revealed the extent of the destruction of the antiquities. During the past few decades we have seen interest in approaching sites of recent conflict using archaeological methods that could help researchers understand these transformations of matter in a deeper way. Such is the case of Asine, a palimpsest landscape with archaeological and historical remains of human activity extending from prehistoric to modern European times. This article will attempt to reveal this hidden side of contemporary history and offer a glimpse into the lives of the last inhabitants of the ancient city.

Research on FSI effect and simplified method of PCS water tank of nuclear island building under earthquake

Water tank is one of the most important components of passive containment cooling system (PCS) in advanced nuclear power plant. Moreover, the dynamic characteristics of shield building and auxiliary building might be changed because of fluid-structure interaction (FSI) of the PCS. Therefore, FSI between cooling water and the shield building should be considered in the dynamic analysis of the nuclear island building. To study the FSI effect and propose an effective and simplified method, three numerical models were established and analyzed under three-dimensional seismic loadings. Acceleration time histories of reference points in the shield building and auxiliary building were got and floor response spectra were calculated. The results show that FSI effect could not be regarded to decrease the seismic response simply but it should be considered in structure design and analysis. A simplified model is proposed in this study and proved to have a good agreement with the FSI model in the curves of floor response spectra. The conclusions could provide reference for further study in the field of nuclear island building.

Auxiliary brood cell construction in nests of the stingless bee Plebeia lucii (Apidae: Meliponini)

Queen production in stingless bees with fusion of neighboring brood cells occurs by the perforation of the adjacent brood cell or construction of an auxiliary one. This study describes the auxiliary brood cell building behavior in queenless colonies of Plebeia lucii. Queenright and queenless (orphan) colonies were monitored, and auxiliary cell construction was video-recorded in orphan colonies. Brood cells with auxiliary cells added were analyzed with X-rays to identify the amount of food and the larval behavior into the brood cells. Plebeia lucii had specific behavioral sequence in auxiliary cell building. The addition of auxiliary cells is the main strategy to produce queens in P. lucii, mainly for the production of emergency queens in orphan colonies because queen absence triggered a high production of auxiliary cells. X-ray analyses showed that auxiliary cell addition occurred when the food in the larval brood cells had been completely eaten and showed changes in dorsoventral position of the larvae. Larvae of males did not perforate auxiliary cells, indicating that sex-related factors affect this behavior. The wax handling by workers and the fused thin and concave-shaped wall between the auxiliary and larval brood cells seems to facilitate wall perforation by the larvae.

Seismic Assessment and Performance of Nonstructural Components Affected by Structural Modeling

Abstract Seismic probabilistic risk assessment (SPRA) requires a large number of simulations to evaluate the seismic vulnerability of structural and nonstructural components in nuclear power plants. The effect of structural modeling and analysis assumptions on dynamic analysis of 3D and simplified 2D stick models of auxiliary buildings and the attached nonstructural components is investigated. Dynamic characteristics and seismic performance of building models are also evaluated, as well as the computational accuracy of the models. The presented results provide a better understanding of the dynamic behavior and seismic performance of auxiliary buildings. The results also help to quantify the impact of uncertainties associated with modeling and analysis of simplified numerical models of structural and nonstructural components subjected to seismic shaking on the predicted seismic failure probabilities of these systems.

Tamdrup – Kongsgård og mindekirke i nyt lys

Tamdrup – Kongsgård og mindekirke i nyt lys

Shock vibration and damage responses of primary auxiliary buildings from aircraft impact

Safety assessments on nuclear power plants (NPPs) subjected to an aircraft impact (AI) caused by terrorists are pivotal focuses for amelioration of present. To date, most studies have mainly focused on structure responses and the integrity of the containment building at a nuclear island (NI) subjected to AI. However, the safety assessment of internal equipment and components by shock vibration as well as the structure damage induced by AI are also important. In this study, aircraft impact analyses (AIA) of primary auxiliary buildings (PABs) were carried out using both the force–time history method and the missile–target interaction method. For the AIA, the jet fuel was taken into account by using the added mass modeling method and the smooth particles hydrodynamics (SPH) method, respectively. In addition, the floor response spectra (FRS) and the structural integrity of the external wall of the PAB against an AI were analyzed. Finally, the difference in the FRS at the location of the components on both sides of the bay was analyzed.

Analysis of flammability in the attached buildings to containment under severe accident conditions

Right after the events unfolded in Fukushima Daiichi, the European Union countries agreed in subjecting Nuclear Power Plants to Stress Tests as developed by WENRA and ENSREG organizations. One of the results as implemented in many European countries derived from such tests consisted of mandatory technical instructions issued by nuclear regulatory bodies on the analysis of potential risk of flammable gases in attached buildings to containment.The current study addresses the key aspects of the analysis of flammable gases leaking to auxiliary buildings attached to Westinghouse large-dry PWR containment for the specific situation where mitigating systems to prevent flammable gases to grow up inside containment are available, and containment integrity is preserved – hence avoiding isolation system failure. It also provides a full practical exercise where lessons learned derived from the current study – hence limited to the imposed boundary conditions – are applied.The leakage of gas from the containment to the support buildings is based on separate calculations using the EPRI-owned Modular Accident Analysis Program, MAAP4.07.The FATE™ code (facility Flow, Aerosol, Thermal, and Explosion) was used to model the transport and distribution of leaked flammable gas (H2 and CO) in the penetration buildings. FATE models the significant mixing (dilution) which occurs as the released buoyant gas rises and entrains air. Also, FATE accounts for the condensation of steam on room surfaces, an effect which acts to concentrate flammable gas.The results of the analysis show that during a severe accident, flammable conditions are unlikely to occur in compartmentalized buildings such as the one used in the analyzed exercise provided three conditions are met: H2 and CO recombiner devices are found inside the containment; corium is submerged and cooled down to quenching by flooding the reactor cavity; and the containment remains isolated along the accident evolution so that gases flowing into attached buildings to containment are limited to the so-called allowable leakage.

Development of a computerized risk management system for international NPP EPC projects

Over the past decade, Nuclear Power Plant (NPP) projects have been increasingly forced to cope with potential risks, which seriously impacted achieving the target completion time and cost. NPP projects have frequently exceeded the planned time and cost despite reliable estimates at the start of the project. This was attributed to unpredictable causes at the beginning and to shortage of proper tools to quantitatively analyze the inevitable uncertainties. To overcome these difficulties, computerized systems have been widely proposed in the construction industry as effective aids to proactively control the potential risks and to monitor continuously their status and variation. However, there are few risk management systems focused on NPP projects. In this study, we developed a computer-based risk management system for NPP projects, called Nuclear Risk Management System (NuRMS), which is helpful for furnishing project managers with warning signals as a project is progressing and for tracking the changes in risk variation at a desired confidence level. In developing the NuRMS, the Risk Breakdown Structure (RBS), the weights for risk categorization, computation of the Total Risk Score (TRS), and integration of risk analysis tools with relation-based and cost-loaded activity schedule were core tasks. To demonstrate the efficiency of the developed NuRMS, the system was operated using risk information derived from constructing the auxiliary buildings of Shin-Kori units 3 and 4 located in Korea, as an illustrative case. The results showed the system's capacities and suggested that it may be applied to a real NPP engineering, procurement, and construction project. The developed NuRMS is expected to assist a project manager in monitoring, tracking, and controlling potential impacts of risk events during the overall implementation of NPP projects.

PENGARUH VARIASI WAKTU CURAH HUJAN TERHADAP KARAKTERISTIK RIGID PAVEMENT DENGAN METODE KUAT TEKAN BETON

Roads are road transport infrastructures covering all sections of the road, including auxiliary buildings and equipment intended for traffic, located on the soil surface, above the soil surface, below ground and / or water, and above the water surface, except roads trains, lorries, and cable roads. Public roads are roads dedicated to general traffic. Parts of the Road are parts of the road covering the road space, road space, and road control room. (Regulation of the Minister of Public Works, Number: 20 / PRT / M / 2010). There is a term that states that 3 (three) main enemies of the road are the first water, second water and third also water. From it can be stated that water, one of which rain water causes damage or reduce the durability of a road construction.pengaruh curah hujan terhadap karakteristik Rigid Pavement dan kuat tekan beton. There is a term that states that 3 (three) main enemies of the road are the first water, second water and third water. From it can be stated that water, one of the rain water causes damage or reduce the durability of a road construction.

Progress in the integration of the ITER plant systems in auxiliary buildings

The ITER Tokamak machine is located in the center of Tokamak complex buildings consisting of Tokamak, Diagnostic, and Tritium buildings. Around the Tokamak complex there are over 30 auxiliary buildings housing various plant systems serving the Tokamak machine either directly or indirectly. The layout and space allocation of each auxiliary building and plant systems housed by the building are represented in the so-called Configuration Management Models (CMM). These are light 3D CAD models that define the required space envelope and the physical interfaces between the systems and the buildings and in-between the systems. The paper describes the CMM and interface management processes of the ITER auxiliary buildings and plant systems, and discusses the preparations for the plant installation phase. In addition, the current baseline configuration of the ITER plant systems in auxiliary buildings is described together with the recent developments in the configuration of different systems, as well as the current status of the construction of the buildings.

Robotic suction nozzle design optimization for severe accident portable air-cleaning system

A new portable filtered air-suction system (PoFASS) is proposed in this paper to prevent the release of radioactive fission products into the atmosphere from severe core meltdown accidents in nuclear power plants (NPPs), which has become very important after the Fukushima accident. The PoFASS consists of a robot arm with a vent line, a robot body equipped with a radioactive filter, and a robot suction nozzle that is the shape of a hand with fingers. By controlling the angle of the robot fingers on the robot suction nozzle, it can change its own shape to completely adapt to cover the damaged sections found in NPPs, and consequently, radioactive release to the atmosphere is effectively prevented. Surveying all the possible shapes of damaged sections in non-containment structures, six distinctive cases were identified. The minimum number of robot fingers that can cover all six cases of damaged sections was mathematically determined to be four, but in the design of the suction nozzle, six robot fingers were included to take into consideration the extension limit of the extensible cover of the suction nozzle as well as the area to be covered at the damaged sections. A complete mathematical model was developed to validate the covering capacity of the designed suction nozzle for all six cases. The minimum number of robot arm rods to access to any damaged section in NPPs was also determined to be three; hence, the PoFASS can access the hatch door of a containment buildings or the damaged sections of containment buildings, turbine buildings, and auxiliary buildings in NPPs. Experimental verification for the proposed PoFASS was successfully done with a prototype suction nozzle for the six cases of damaged sections.

The History of Saint Michael the Archangel Uniate Church in Rogóźno in the Light of the 18th Century Church Visitation

The following work depicts the operating of Saint Michael the Archangel Uniate Church in Rogóźno in the first half of the 18th century. The introduction contains the geographical location of the parish, its size and the place in the hierarchy of the Church. Having analyzed the Bishop of Chełm post-visitation protocols both the appearance of the church and church’s endowment is put forth. As far as possible, the appearance of the presbytery and auxiliary buildings has been determined. Then, not only was the church benefice determined but the number of the faithful and the clergy was defined.

Safety assessment of a nuclear power plant building subjected to an aircraft crash

This paper presents a safety assessment of a nuclear building subjected to an aircraft crash using numerical analysis. For impact simulation, the reinforced concrete (RC) Primary Auxiliary Building (PAB) of the Korea Standard Nuclear Power Plant (KSNP) is fully modeled and an aircraft model of a Boeing 767-400 is used. The Riera function is used to verify the analysis result of impact force–time history. The IRIS test is used to verify the structural behavior of the RC wall under impact loading. The safety assessment of the building is performed with regard to different impact scenarios. The safety of the nuclear building under aircraft crash, including (1) global structural safety, (2) local structural safety, and (3) vibration safety are evaluated and discussed. The results show that the global and local structural safety of the PAB is ensured in all impact scenarios. However, the vibration safety of the building is not ensured. In accordance, the regulatory guide of United States Nuclear Regulatory Commission (U.S. NRC), shutdown of the nuclear power plant is required.

Plant integration of MITICA and SPIDER experiments with auxiliary plants and buildings on PRIMA site

This paper presents a description of the PRIMA (Padova Research on ITER Megavolt Accelerator) Plant Integration work, aimed at the construction of PRIMA Buildings, which will host two nuclear fusion test facilities named SPIDER and MITICA, finalized to test and optimize the neutral beam injectors for ITER experiment. These activities are very complex: inputs coming from the experiments design are changing time to time, while the buildings construction shall fulfill precise time schedule and budget. Moreover the decision process is often very long due to the high number of stakeholders (RFX, IO, third parties, suppliers, domestic agencies from different countries). The huge effort includes: forecasting what will be necessary for the integration of many experimental plants; collecting requirements and translating into inputs; interfaces management; coordination meetings with hundreds of people with various and different competences in construction and operation of fusion facilities, thermomechanics, electrical and control, buildings design and construction (civil plants plus architectural and structural aspects), safety, maintenance and management.The paper describes these activities and also the tools created to check and to validate the building design, to manage the interfaces and the organization put in place to achieve the required targets.

Seismic response analysis of a piping system subjected to multiple support excitations in a base isolated NPP building

In this study, the stress response of the piping system in the advanced power reactor 1400 (APR 1400) with a base isolation design subjected to seismic loading is addressed. The piping system located between the auxiliary building with base isolation and the turbine building with a fixed base is considered since it can be subjected to substantial relative support movement during seismic events. First, the support responses with respect to the base characteristic are investigated to perform seismic analysis for multiple support excitations. Finite element analyses are performed to predict the piping stress response through various analysis methods such as the response spectrum, seismic support movement and time history method. To separately evaluate the inertial effect and support movement effect on the piping stress, the stress is decomposed into a primary and secondary stress using the proposed method. Finally, influences of the base isolation design on the piping system in the APR 1400 are addressed. The primary stress based on the inertial loading is effectively reduced in a base isolation design, whereas a considerable amount of secondary stress is generated in the piping system connecting a base isolated building with a fixed base building. It is also confirmed that both the response spectrum analysis and seismic support movement analysis provide more conservative estimations of the piping stress compared to the time history analysis.

Software Implementation of an Attribute-Based Encryption Scheme

A ciphertext-policy attribute-based encryption protocol uses bilinear pairings to provide control access mechanisms, where the set of user’s attributes is specified by means of a linear secret sharing scheme. In this paper we present the design of a software cryptographic library that achieves record timings for the computation of a 126-bit security level attribute-based encryption scheme. We developed all the required auxiliary building blocks and compared the computational weight that each of them adds to the overall performance of this protocol. In particular, our single pairing and multi-pairing implementations achieve state-of-the-art time performance at the 126-bit security level.

Estimation of airport noise impacts on public health. A case study of İzmir Adnan Menderes Airport

The air transport industry is showing rapid growth in line with the call for meeting the requirements of a rising population. Noise mapping is more useful than surveys and measurements to estimate the effects of noise on public health. In this paper, noise levels for the day, evening and night time slices around İzmir Adnan Menderes Airport were calculated by use of the SoundPLAN 7.2 software according to the European Noise Directive, and the “ECAC Doc. 29-Interim” method was applied for the computation of the aircraft noise. Air traffic data of year 2012, technical information about the airport and geographical data including the layers of elevation, residential buildings, auxiliary buildings, hospitals and schools were used as the main inputs for the model developed in the study. The model was found to perform well for the areas closer to the airport. The results of the study suggested that the area at the north side of the airport, where the city center of İzmir is located, is more affected than other areas. The threshold value of 55dB(A) was found to be exceeded in 0.3% of the land area covered by İzmir City center during the time slice “day”. The results showed that about 2% of the resident population was exposed to noise levels of 55dB(A) or higher during day-time in İzmir. In addition, it was understood that the number of people who are potentially exposed to high noise levels and threatened by several illness such as hypertension and sleep disturbances is significant in the surrounding area of the airport. It is thought to be important for airport operators to manage the airport capacity based on the flight schedules in order to control the noise exposure level around the airport.