• Nuclear Engineering and Technology
• /
• 제55권2호
• /
• pp.707-716
• /
• 2023

The influence of waste technological waters of thermal and fast reactors of Beloyarsk NPP (Russia) on the accumulation of ⁶⁰Co, ⁹⁰Sr and ¹³⁷Cs in macrophytes and ichthyofauna of the cooling pond has been studied. Critical radionuclides, routes of their entry into the ecosystem and periods of maximum discharge of radioisotopes into the cooling pond have been determined. It is shown that the technology of electricity generation at the Beloyarsk NPP, based on fast reactors, has a much smaller effect on the release of artificial radionuclides into the environment. Therefore, during the entire period of monitoring studies (1976-2019), the decrease in the specific activity of radionuclides of NPP origin in macrophytes was 13-25800 times, in ichthyofauna 1.5-44.5 times. The maximum discharge of artificial radionuclides into the Beloyarsk reservoir was noted during the period of restoration and decontamination work aimed at eliminating the emergencies at the AMB reactors of NPP. The factors influencing the accumulation of artificial radionuclides in the components of the freshwater ecosystem of the Beloyarsk cooling pond have been determined, including: the physicochemical nature of radioisotopes, their concentration in surface water, the temperature of the aquatic environment, the trophicity of the reservoir, the species of hydrobionts.

• 설비공학논문집
• /
• 제29권6호
• /
• pp.316-326
• /
• 2017

Commercial buildings and institutions are predominantly cooled, thereby dissipating excess heat to a vertical ground heat exchanger (VGHE), than heat extracted over an annual cycle. Surface waters, such as lakes and ponds, provide a cost-effective means of reducing the VGHE length, and in balancing the thermal loads to the ground. This paper presents the measurement and analysis of the cooling performance of ground-coupled heat pump (GCHP) system, using surface water heat exchanger (SWHE) submerged in an artificial pond. In order to measure the performance of the system, we installed monitoring equipment, including sensors, for assessing the temperature and power consumption, after which the operation parameters were determined. The results from the thermal performance test for the SWHE indicate that the temperatures at the outlet of the SWHE and within the pond were affected by outdoor air temperature. In addition, the results reveal similar variation trends on temperatures; however, the peak temperatures of the SWHE were somewhat greater than those of outdoor air, due to the thermal capacity of the pond. Analyzing the cooling performance over the measurement period, the average coefficient of performance (COP) of heat pump was found to be 5.71, while that for the entire system was 2.99.

• 한국태양에너지학회:학술대회논문집
• /
• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
• /
• pp.85-89
• /
• 2008

This study carried out field observations of measuring thermal environment, especially evaluating amount of water evaporation at roof Pond by field observations during the summer. Thermal environment measuring was categorized as air temperature, water temperature of roof pond, surface temperature, globe temperature, short and long wave radiation, net radiation, and amount of water evaporation by water level measurement. Results from this study could be used as fundamental for reducing heat Island phenomena.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 2002년도 추계학술발표회요약집
• /
• pp.113.1-113
• /
• 2002

• Nuclear Engineering and Technology
• /
• 제54권8호
• /
• pp.3034-3042
• /
• 2022

The results of radioecological monitoring of the cooling pond Beloyarsk NPP (Russia) have been presented. The influence of waste technological waters of thermal and fast NPP reactors on the content of artificial radionuclides in surface waters and bottom sediments of the Beloyarsk reservoir has been studied. The long-term dynamics of the specific activity of ⁶⁰Co, ⁹⁰Sr, ¹³⁷Cs and ³H in the main components of the freshwater ecosystem at different distances from the source of radionuclide discharge has been estimated. Critical radionuclides (⁶⁰Co and ¹³⁷Cs), routes of their entry and periods of maximum discharge of radioisotopes into the cooling pond have been determined. It is shown that the technology of electricity generation at Beloyarsk NPP, based on fast reactors, has a much smaller effect on the flow of artificial radionuclides into the freshwater ecosystem of the reservoir. During the entire period of monitoring studies, the decrease in the specific activity of radionuclides from NPP origin in surface waters was 4.3-74.5 times, in bottom sediments 10-505 times. The maximum discharge of artificial radionuclides into the reservoir was noted during the period of restoration and decontamination work aimed at eliminating emergencies at the AMB thermal reactors of the first stage of the Beloyarsk NPP.

• 한국지열·수열에너지학회논문집
• /
• 제14권4호
• /
• pp.43-52
• /
• 2018

This paper presents the cooling performance analysis results of a ground-source heat pump (GSHP) system using hybrid ground heat exchanger (HGHE). In this paper, the HGHE refers to the ground heat exchanger (GHE) using both a vertical GHE and a surface water heat exchanger (SWHE). In order to evaluate the system performance, we installed monitoring sensors for measuring temperatures and power consumption, and then measured operation data with 4 different load burdened ratios of the hybrid GHE, Mode 1~Mode 4. The measurement results show that the system with HGHE mainly operates in Mode 1 and Mode 2 over the entire measurement period. The average cooling coefficient of performance (COP) for heat pump unit was 5.18, while the system was 2.79. In steady state, the heat pump COP was slightly decreased with an increase of entering source temperature. In addition, the parallel use of SWHE and VGHE was beneficial to the system performance; however, further research are needed to optimize the design data for various load ratios of the HGHE.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
• /
• 제16권1호
• /
• pp.43-53
• /
• 2010

This study purports to investigate the status quo of the environmentally-friendly green healthcare in teaching hospitals through the questionnaire survey. Data were collected from a total of 46 hospitals. The survey results revealed that most teaching hospitals did not meet the global standard of environmentally-friendly green hospitals. Especially, such items as alternative energy system, water recycling, CO2 emission reduction, green building construction, installation of pond or spring were found to be significantly below global standard. Based upon the study results, various strategies for establishing green hospitals were discussed. For example, energy saving design, such as solar heating, natural wind cooling, automatic temperature controller, green material use, wall surrounded by ivy, were recommended. In conclusion, the strategy and evaluation tool developed in the study will provide a good guide for establishing environmentally-friendly green hospitals.

• Nuclear Engineering and Technology
• /
• 제43권6호
• /
• pp.489-498
• /
• 2011

UK National Nuclear Laboratory's (NNL's) version of the ENIGMA fuel performance code is described, including details of the development history, the system modelled, the key assumptions, the thermo-mechanical solution scheme, and the various incorporated models. The recent development of ENIGMA in the areas of whole core analysis and dry storage applications is then discussed. With respect to the former, the NEXUS code has been developed by NNL to automate whole core fuel performance modelling for an LWR core, using ENIGMA as the underlying fuel performance engine. NEXUS runs on NNL's GEMSTONE high performance computing cluster and utilises 3-D core power distribution data obtained from the output of Studsvik Scandpower's SIMULATE code. With respect to the latter, ENIGMA has been developed such that it can model the thermo-mechanical behaviour of a given LWR fuel rod during irradiation, pond cooling, drying, and dry storage - this involved: (a) incorporating an out-of-pile clad creep model for irradiated Zircaloy-4; (b) including the ability to simulate annealing out of the clad irradiation damage; (c) writing of additional post-irradiation output; (d) several other minor modifications to allow modelling of post-irradiation conditions.

• 대한기계학회논문집 C: 기술과 교육
• /
• 제4권1호
• /
• pp.49-56
• /
• 2016

본 연구에서는 설계 인자가 지표수 열교환기 길이에 미치는 영향을 분석하였다. 또한 수직 밀폐형 지중열교환기와 지표수 열교환기를 같이 이용한다고 가정한 후, 지중 순환수의 온도 변화를 분석하였다. 지표수 열교환기 출구 온도와 연못 온도의 차이를 크게 하면, 열교환기 파이프 길이는 줄어들었다. 아울러 연못 온도가 높을수록 파이프 길이는 감소하지만, 파이프 바깥지름의 영향은 상대적으로 적었다. 또한 파이프 두께가 얇을수록 전도 열전달에서 열저항의 영향이 감소하기 때문에 파이프 길이는 감소하였다. 수직 밀폐형 시스템에 지표수 열교환기를 추가 적용하면, 지중열교환기 순환수 온도는 시간이 지날수록 감소하였다.

• 한국지열·수열에너지학회논문집
• /
• 제12권3호
• /
• pp.24-32
• /
• 2016

Commercial buildings and institutions are generally cooling-dominated and therefore reject more heat to a borehole ground heat exchanger (BHE) than they extract over the annual cycle. Shallow ponds can provide a cost-effective means to balance the thermal loads to the ground and to reduce the length of BHE. This paper presents the analysis results of the impact of design parameters on the length of SWHE pipe and its application effect on geothermal heat pump (GHP) system using BHE. In order to analysis, we applied ${\varepsilon}-NTU$ method on designing the length of SWHE pipe. Analysis results show that the required pipe length of SWHE was decreased with the increase of approach temperature difference and with the decrease of pipe wall thickness. In addition, when the SWHE was applied to the GHP system, the temperature of BHE was more stable than that of standalone BHE system.