scholarly journals A unique subtidal vermetid reef formation in a nuclear power plant discharge area at Ilha Grande Bay (southwestern Atlantic Ocean)

2016 ◽  
Vol 9 (1) ◽  
Author(s):  
André Breves ◽  
Fernando Coreixas Moraes ◽  
Alexandre Dias Pimenta ◽  
Andrea Oliveira Ribeiro Junqueira
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Atlantic Ocean ◽  
Nuclear Power ◽  
Southwestern Atlantic ◽  
Discharge Area ◽  
Southwestern Atlantic Ocean ◽  
Reef Formation

Long term variation of 137Cs inventory in the global ocean from 1957 to 2018

2021 ◽  
Author(s):  
Yayoi Inomata ◽  
Michio Aoyama
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Atlantic Ocean ◽  
Nuclear Fuel ◽  
Nuclear Power ◽  
Global Ocean ◽  
Surface Seawater ◽  
Average Value ◽  
Nuclear Fuel Reprocessing ◽  
Fuel Reprocessing

<p>The spatial and temporal variations in <sup>137</sup>Cs concentrations in the surface seawater in the global ocean from 1957 to 2018 were analyzed by using the ''HAM database - global 2018'' and “IAEA-MARIS database” in order to understand the behaviors of <sup>137</sup>Cs originated atmospheric weapons tests, nuclear fuel reprocessing plants, and nuclear power plant accidents at Chernobyl and Fukushima. The global ocean was divided into 37 boxes. The 0.5yr average value of <sup>137</sup>Cs, apparent half residence times (Tap), and <sup>137</sup>Cs inventory in each box was estimated. The 0.5yr average value of <sup>137</sup>Cs in each oceanic region (box) indicate that <sup>137</sup>Cs decreased exponentially from 1970 to 2010 in the Pacific Ocean (PO), Indian Ocean (IO), and Atlantic Ocean (AO), except for the Arctic Ocean, North Atlantic Ocean and its marginal sea due to the discharge of<sup> 137</sup>Cs from the nuclear fuel reprocessing plants. The geographical difference of <sup>137</sup>Cs activity concentrations in the global ocean become to be small in the year of 2010. The temporal variation of <sup>137</sup>Cs column inventory suggests that <sup>137</sup>Cs derived from the large scale atmospheric weapon tests exist largely in the subtropical NPO, equatorial PO, and subtropical SPO (25°N-25°S). <sup>137</sup>Cs transport from the PO to the IO occurs in the region from 0°-15°S via Indonesian through flow. The signature of <sup>137</sup>Cs transport from the IO to the AO is also detected. The <sup>137</sup>Cs inventory in the surface seawater in the year 2010 is estimated to be 57±17 PBq. Considering that the radioactive decay <sup>137</sup>Cs are estimated to be 347 PBq, the<sup> 137</sup>Cs existed into the ocean interior is estimated to 173±52 PBq. These indicate that about 30% of <sup>137</sup>Cs released into the surface seawater have been transported into the ocean interior in 2010. The <sup>137</sup>Cs inventory in 2011 in the surface seawater in the global ocean were 69±15 PBq. The<sup> 137</sup>Cs released by the Fukushima Nuclear Power Plant 1 accident increased to 16.5±4.8 PBq and this value is in good agreement with previous studies.</p>

Fuzzy multi-objective decision making approach for nuclear power plant installation

2020 ◽  
Vol 39 (5) ◽  
pp. 6339-6350
Author(s):  
Esra Çakır ◽  
Ziya Ulukan
Keyword(s):  
Linear Programming ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Energy Supply ◽  
Energy Demand ◽  
Nuclear Power ◽  
Power Plants ◽  
Total Duration ◽  
Objective Functions ◽  
Multi Objective

Due to the increase in energy demand, many countries suffer from energy poverty because of insufficient and expensive energy supply. Plans to use alternative power like nuclear power for electricity generation are being revived among developing countries. Decisions for installation of power plants need to be based on careful assessment of future energy supply and demand, economic and financial implications and requirements for technology transfer. Since the problem involves many vague parameters, a fuzzy model should be an appropriate approach for dealing with this problem. This study develops a Fuzzy Multi-Objective Linear Programming (FMOLP) model for solving the nuclear power plant installation problem in fuzzy environment. FMOLP approach is recommended for cases where the objective functions are imprecise and can only be stated within a certain threshold level. The proposed model attempts to minimize total duration time, total cost and maximize the total crash time of the installation project. By using FMOLP, the weighted additive technique can also be applied in order to transform the model into Fuzzy Multiple Weighted-Objective Linear Programming (FMWOLP) to control the objective values such that all decision makers target on each criterion can be met. The optimum solution with the achievement level for both of the models (FMOLP and FMWOLP) are compared with each other. FMWOLP results in better performance as the overall degree of satisfaction depends on the weight given to the objective functions. A numerical example demonstrates the feasibility of applying the proposed models to nuclear power plant installation problem.

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