• Nuclear Engineering and Technology
• /
• v.53 no.9
• /
• pp.3085-3099
• /
• 2021

Investigations of large commercial aircraft impact effect on nuclear power plant (NPP) buildings have been drawing extensive attentions, particularly after the 9/11 event, and this paper aims to numerically assess the damage and vibrations of NPP buildings subjected to aircrafts crash. In Part I of present paper, two shots of reduce-scaled model test of aircraft impact on NPP were conducted based on the large rocket sled loading test platform. In the present part, the numerical simulations of both scaled and prototype aircraft impact on NPP buildings are further performed by adopting the commercial program LS-DYNA. Firstly, the refined finite element (FE) models of both scaled aircraft and NPP models in Part I are established, and the model impact test is numerically simulated. The validities of the adopted numerical algorithm, constitutive model and the corresponding parameters are verified based on the experimental NPP model damages and accelerations. Then, the refined simulations of prototype A380 aircraft impact on a hypothetical NPP building are further carried out. It indicates that the NPP building can totally withstand the impact of A380 at a velocity of 150 m/s, while the accompanied intensive vibrations may still lead to different levels of damage on the nuclear related equipment. Referring to the guideline NEI07-13, a maximum acceleration contour is plotted and the shock damage propagation distances under aircraft impact are assessed, which indicates that the nuclear equipment located within 11.5 m from the impact point may endure malfunction. Finally, by respectively considering the rigid and deformable impacts mainly induced by aircraft engine and fuselage, an improved Riera function is proposed to predict the impact force of aircraft A380.

• International conference on construction engineering and project management
• /
• 2017.10a
• /
• pp.8-13
• /
• 2017

Nuclear power plant (NPP) constructions are large scale projects that are executed for several years, and schedule control utilizing various schedules is a critically important factor. Recently Korea independently developed the Advanced Power Reactor (APR) 1400 and is building nuclear facilities applying this new reactor type. The construction of Shin-Kori NPP (SKN) Unit 3, which adopted the APR1400, was completed and commercial operation has begun, while, SKN 4, Shin-Hanul NPP (SHN) Units 1&2, and SKN 5&6 are currently under construction. Prior to the development of the APR1400, Korea built 24 reactors and accumulated the schedule data of various reactor types which provided the foundation for schedule reduction to be possible. However, as there is no schedule development and review system established based on the standard schedule data (standard activities, durations, etc.) by reactor type, the process for developing the schedule for new builds is low in efficiency consuming much time and manpower. Also all construction data has been accumulated based on schedule activities. But because the connectivity of activities between projects is low, it is difficult to utilize such accumulated data (causes for schedule delay, causes for design changes, etc.) in new build projects. Due to such reasons, issues continue to arise in the process of developing standard schedule activities and a standard schedule for nuclear power plant construction. In order to develop a standard schedule for NPP construction, i) the development of an NPP standard schedule activity list, ii) development of the connection logic of NPP standard schedule activities, iii) development of NPP standard schedule activity resources and duration, and iv) integration of schedule data need to be performed. In this paper, an analysis was made on the coherence of schedule activity descriptions of existing NPPs by applying the probabilistic methodology on activities with low connectivity due to the utilization of the numbering system of four APR1400 reactors (SHN 1&2 and SKN 3&4).This study also describes the method for developing a standard schedule activity list and connectivity measures by extracting same and/or similar schedule activities.

• Nuclear industry
• /
• v.18 no.7 s.185
• /
• pp.49-54
• /
• 1998

• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.6 no.1
• /
• pp.72-77
• /
• 2010

During the period of reinforcement work for the licensing renewal of CANDU NPP, the fuel channels, Calandria tubes and feeders of CANDU Reactor are replaced. The remote visual inspection of Calandria internal is also performed during the period of reinforcement work. This period is a unique opportunity to inspect the inside of the Calandria. The visual inspection for the Calandria vessel and its internals of Wolsong NPP Unit 1 was performed by Nuclear Engineering & Technology Institute(NETEC) of KHNP. To perform this inspection, NETEC developed equipment applied new technology such as the synchronization of 3D CAD, automatic alignment and control system. The inspection confirmed that the Calandria integrity of Wolsong NPP Unit 1 is perfect.

• Nuclear Engineering and Technology
• /
• v.41 no.8
• /
• pp.1065-1072
• /
• 2009

As the use of software increases at nuclear power plants (NPPs), the necessity for including software reliability and/or safety into the NPP Probabilistic Safety Assessment (PSA) rises. This work proposes an application procedure of software reliability growth models (RGMs), which are most widely used to quantify software reliability, to NPP PSA. Through the proposed procedure, it can be determined if a software reliability growth model can be applied to the NPP PSA before its real application. The procedure proposed in this work is expected to be very helpful for incorporating software into NPP PSA.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.18 no.6
• /
• pp.261-269
• /
• 2014

In order to increase the seismic safety of nuclear power plant (NPP) structures in high seismicity regions, seismic isolation techniques can be adapted to NPP structures. In this paper, the applicability of multi-step analysis of seismically isolated NPP containment structures with lead-rubber bearings (LRB) is evaluated. The floor response spectrum of NPP containment structures with equivalent linear LRB and nonlinear LRB are compared. In addition, the force-displacement relationships for equivalent linear LRB and nonlinear LRB are compared.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.447-449
• /
• 2003

Remotely sensed data can be used to estimate biomass production using methodologies relating vegetation indices to light absorption or to leaf photosynthetic capacity. The considerations of both light absorption and photosynthetic capacity in remote sensing-based modeling to estimate biomass production or NPP was introduced based upon Monteith model NPP is one of a evaluation of land degradation. NPP was estimated from annual maximum NDVI by MODIS data. It was known that NPP of the grassland that except the forest and the farming ground was distributed between 50-200g /m2.

• Fire Science and Engineering
• /
• v.5 no.3
• /
• pp.15-22
• /
• 1991

It has been generally accepted that nuclear power (NPP) is suiable for power supply in korea because of its economical profits and pollution-free energy. When designing or operating a NPP. The main points to be home in mind are the hazards of and protection against an uncontrolled release of the large quantities of radioactiv substances which are always generated in a nuclear reactor while it is in iperation. Multiple independent safety systems are provided which should prevent this from occurring. Thus fire prevention measures in NPP follow the “Defense-in-depth” concept. This study aims to suggest the fire prevention measures and to demonstrate information which is needed for NPP planning and its safety assessment. The findings of this study can be used as useful data for fire protection plannings at the first phase of NPP design.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.302-304
• /
• 2019

탄소 순환과 수문 순환의 관계를 이해하기 위해서는 효율적인 물 사용과 실제 물 사용 간의 비율로 정의되는 용수효율(Water Use Efficiency; WUE)을 정량화 하는 것이 필요하다. 특히 용수효율을 평가하기 위해서는 탄소 순환의 주요 인자인 총 1차 생산량(Gross Primary Productivity; GPP)과 순 1차 생산량(Net Primary Productivity; NPP)을 산정하는 것이 중요하다. 본 연구에서는 전 세계적으로 가장 많이 활용되고 있는 지면 모형 중 하나인 Community Land Model(CLM)을 활용하여 동아시아 지역에서의 GPP와 NPP를 산정하였다. 모형을 통해서 산정된 광역의 GPP와 NPP는 Flux tower에서 관측된 지점 자료를 활용하여 검증할 예정이다. 또한 지면 모형에서 획득한 동아시아 지역의 GPP와 NPP에 대한 공간 분포를 분석하여 탄소 순환 인자들에 대한 시공간적인 변화에 대하여 확인하고자 한다.

• Plant Journal
• /
• v.5 no.3
• /
• pp.66-73
• /
• 2009

This study aims to develop a strategy for South Korean companies to penetrate into the global NPP(nuclear power plant) market with their strength as the sixth biggest nuclear power generator in the world. With 20 nuclear plants in commercial operation and 6 more in construction, South Korea has the best technology in construction and operation of NPP. Despite these capabilities as demonstrated on its domestic market, Korean companies' constraint to enter and play a key role in global NPP market would be the lack of experience in overseas NPP projects, original technologies, and diplomatic effectiveness. This study analyzes the competitiveness of Korean standardized nuclear power plant, construction management skills, construction technologies, manufacturing equipment and materials and operation skills. In this research the current status of existing NPP and the forecast of building NPP according to countries was analyzed in order to work out strategies with technology, cost-effectiveness, and diplomatic consideration.