• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2018.11a
• /
• pp.104-104
• /
• 2018

Kori Unit 1 is the first permanent shutdown nuclear power plant in Korea and it is on June 18th, 2017. Spent fuel assemblies began to be discharged from the reactor core to the spent fuel pool(SFP) within one week after shutdown of Kori unit 1 and the campaign was completed on June 27th, 2017. The total number of spent nuclear fuel assemblies in SFP of Kori Unit-1 is 485 and their discharging date is different respectively. So, decay heat was evaluated considering the actual enrichment, operation history and cooling time of the spent fuel assemblies stored in SFP of the Kori Unit-1. The code used in the evaluation is the ORIGEN-based CAREPOOL system developed by KHNP. Decay heat calculation of PWR fuel is based on ANSI/ANS 5.1-2005, "Decay heat power in light water reactors" and ISO-10645, "Nuclear energy - Light water reactors - Calculation of the decay heat power in nuclear fuels. Also, we considered the contribution of fission products, actinide nuclides, neutron capture and radioactive material in decay heat calculation. CAREPOOL system calculates the individual and total decay heat of all of the spent fuel assemblies in SFP of Kori Unit-1. As a result, the total decay heat generated in SFP on June 28th, 2017 when the spent fuel assemblies were discharged from the reactor core, is estimated to be about 4,185.8 kw and to be about 609.5 kw on September 1st, 2018. It was also estimated that 119.6 kw is generated in 2050 when it is 32 years after the permanent shutdown. Figure 1 shows the trend of total decay heat in SFP of Kori Unit-1.

• Education of Primary School Mathematics
• /
• v.17 no.3
• /
• pp.231-251
• /
• 2014

The number and units are not apart from each other, especifically units clarifies number. Students often encounters many problems involving units, researcher found that students have difficulty in recognize the meaning of calculation results. These students recognizes units, just presented thing in the problem. And they could not connect units with the meaning of calculation results. With this results, this study researched limitation of pre serviced didactic transposition and found the effectness of using units to recognize the meaning of calculation results. Especially we discussed didactic transposition with permitting probability of unit calculation and suggested implications. So we accented the inevitability of change, and tried to offer substantial help.

• Nuclear Engineering and Technology
• /
• v.52 no.10
• /
• pp.2221-2229
• /
• 2020

After the Fukushima Daiichi nuclear power plant (NPP) accident, level 3 probabilistic safety assessment (PSA) has emerged as an important task in order to assess the risk level of the multi-unit NPPs in a single nuclear site. Accurate calculation of the radionuclide concentrations and exposure doses to the public is required if a nuclear site has multi-unit NPPs and large number of people live near NPPs. So, there has been a great need to develop a new method or procedure for the fast and accurate offsite consequence calculation for the multi-unit NPP accident analysis. Since the multi-unit level 3 PSA is being currently performed assuming that all the NPPs are located at the same position such as a center of mass (COM) or base NPP position, radionuclide concentrations or exposure doses near NPPs can be drastically distorted depending on the locations, multi-unit NPP alignment, and the wind direction. In order to overcome this disadvantage of the COM method, the idea of a new multiple location (ML) method was proposed and implemented into a new tool MURCC (multi-unit radiological consequence calculator). Furthermore, the MURCC code was further improved for the multi-unit level 3 PSA that has the arbitrary number of multi-unit NPPs. The objectives of this study are to (1) qualitatively and quantitatively compare COM and ML methods, and (2) demonstrate the strength and efficiency of the ML method. The strength of the ML method was demonstrated by the applications to the multi-unit long-term station blackout (LTSBO) accidents at the four-unit Vogtle NPPs. Thus, it is strongly recommended that this ML method be employed for the offsite consequence analysis of the multi-unit NPP accidents.

• East Asian mathematical journal
• /
• v.31 no.2
• /
• pp.211-244
• /
• 2015

The arithmetic operation have double-sided character. One is calculation as a process, the other is understanding in results as an outcome of the operation. We harbored suspicion on students' misunderstanding in an outcome of the operation, because the curriculum has focused on the calculation, as a process of arithmetic operation. This study starts with the presentation of this problem, we tried to find the recognition ability and character in the arithmetic operation. We researched the recognition ability for 7th grade 27 students who have enough experience in arithmetic operation when studying in elementary school. And we had an interview with 3students individually, that has an error in understanding in results of arithmetic operation but has no error in calculation. We focused on 3students' detailed appearance of the ability to understand in results of arithmetic operation and analysed the changing appearance after recommending unit record using operation expression. As a result, we could find the abily to underatanding in results of arithmetic operation and applicability to recommend unit record using operation expression. Through these results, we suggested educational implications in understanding in results of arithmetic operation.

• Nuclear Engineering and Technology
• /
• v.47 no.7
• /
• pp.849-858
• /
• 2015

This study set the pyroprocess facility at an engineering scale as a cost object, and presented the cost consumed during the unit processes of the pyroprocess. For the cost calculation, the activity based costing (ABC) method was used instead of the engineering cost estimation method, which calculates the cost based on the conceptual design of the pyroprocess facility. The calculation results demonstrate that the pyroprocess facility's unit process cost is $194/kgHM for pretreatment, $298/kgHM for electrochemical reduction, $226/kgHM for electrorefining, and $299/kgHM for electrowinning. An analysis demonstrated that the share of each unit process cost among the total pyroprocess cost is as follows: 19% for pretreatment, 29% for electrochemical reduction, 22% for electrorefining, and 30% for electrowinning. The total unit cost of the pyroprocess was calculated at $1,017/kgHM. In the end, electrochemical reduction and the electrowinning process took up most of the cost, and the individual costs for these two processes was found to be similar. This is because significant raw material cost is required for the electrochemical reduction process, which uses platinum as an anode electrode. In addition, significant raw material costs are required, such as for $Li_3PO_4$, which is used a lot during the salt purification process.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2020.06a
• /
• pp.202-203
• /
• 2020

Unlike price calculation by cost accounting, which categorizes costs into material costs, labor costs, and miscellaneous expenses to determine the construction budget price, construction cost calculation based on Construction Standard Unit Prices utilizes unit prices extracted from market prices of items from projects already completed to estimate costs of similar construction projects. Although unit price information is collected through construction site surveys to revise these construction standard unit prices every year, but due to the limitations of the site survey method, it is difficult to quickly implement the rapid changes in the construction methods and market prices. As such, an important issue that arose was the identification of work items whose prices need urgent revision. This study conducted research on factors that need to be considered when developing online survey system for monitoring construction site market prices. This study is expected to enhance convenience for users, and provide an efficient data collection and management system for administrators.

• Journal of Korean Society of Environmental Engineers
• /
• v.37 no.2
• /
• pp.107-112
• /
• 2015

Carbon emissions in construction stage is very high because lots of construction machines and materials are required to be used at a road construction stage. Many researcher carried out application of carbon emissions estimation methodology during the life cycle of road infrastructure in order to reduce greenhouse gas emissions in the road sector. But the calculation of carbon emissions is difficult because data collection is difficult and calculation procedure is complex. In this study, a basic unit of carbon emissions in construction stage of the road infrastructure was developed in order to get the quantitative determination of carbon that occurs. Carbon emissions of the expressway and common state road was calculated by using the basic unit of carbon emissions and application plan of basic unit of carbon emissions are presented.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.15 no.5
• /
• pp.360-371
• /
• 2003

The calculation of each unit cost of productions is very important for evaluating the economical efficiency and deciding the reasonable sale price. In the present, two methods of exergy costing on multiple energy systems are suggested to reduce the complexities of conventional SPECO method and MOPSA method and to improve the calculation efficiency of exergoeconomics. The suggested methods were applied to a gas-turbine cogeneration and the unit costs of the power and the steam energy were calculated as an example. The main points of our methods are the following three. First, one exergetic cost is applied to one cycle or system. Second, the suggested equations are the internal cost balance equation and the production cost balance equation. Third, necessary states in a system are only inlet and exit states of 1ha components producing energy.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 1995.11a
• /
• pp.153-165
• /
• 1995

When an automatic course-keeping is introduced as is quite popular in modern navigation the closed-loop steering system consists of autopilot device power unit(or telemotor unit) steering gear ship dynamics and magnetic or gyro compass. We derive the mathematical model of each element of the automatic steering system. We provide a method of theoretical analysis on propulsive energy loss related to automatic steering of ships inthe open seas taking account of the on-off mechanism of power unit. Also we paid attention to dead band mechanism of autopilot device which is normally called weather adjustment. Next we make numerical calculation of the effects of autopilot control constants ont he propulsive energy loss for two kinds of ship a fishing boat and an ore carrier. Realistic sea and wind disturbances are employed in the calculation.

• Proceedings of the KSR Conference
• /
• 2005.05a
• /
• pp.225-230
• /
• 2005

This paper describes determination of optimal lubricant quantity for driving gear unit. The purpose of selecting optimal lubricant quantity is to evaluate durability of driving gear unit. Lubricant quantity of driving gear unit is important factor affecting durability. The determination methode of lubricant quantity evaluation is used calculation necessary lubricant quantity first, then selection of optimal oil quantity as a base for moving of oil temperature according to changing oil quantity.