Long-term monitoring dataset of fish assemblages impinged at nuclear power plants in northern Taiwan

Radiocesium monitoring in sediments and river water has been conducted along five rivers in Minami-Soma City during 2012–2016 to clarify the temporal changes of radiocesium contamination in these rivers. Sampling has been performed annually under normal flow conditions. Sediment and river water samples were collected from four or five sampling sites along each river. Gamma-ray measurements of sediments were performed using a low-background Ge detector and unfiltered river water was utilized to determine radiocesium concentration using a well-type Ge detector. The 137Cs concentration in sediments was highest at upstream sites and slowly decreased to downstream sites for all rivers reflecting the high radioactive contamination in the upstream area. Temporal decrease of the 137Cs concentration was observed in sediments and river water for each river. The effective half-lives were 1.3–2.1 y for sediments, and 0.9–2.1 y for river water from rivers with upstream dams. On the undammed river, the effective half-lives were 4.7 y and 3.7 y for sediment and river water, respectively. Much longer effective-half-lives might reflect the direct transfer of radiocesium from forests and plains to the river. The 137Cs concentration in riverbed was low in downstream areas, however, accumulation of 137Cs over the floodplain was observed. Rapid decrease of 137Cs contamination through rivers will put residents at ease, but high accumulation of radiocesium over floodplains should be noted for future river decontamination.

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Guided Waves as an Online Monitoring Technology for Long-Term Operation in Nuclear Power Plants: Experimental Results on a Steam Discharge Pipe

Journal of Nuclear Engineering and Radiation Science ◽

10.1115/1.4041193 ◽

2019 ◽

Vol 5 (1) ◽

Author(s):

Mauro Cappelli ◽

Francesco Cordella ◽

Francesco Bertoncini ◽

Marco Raugi

Keyword(s):

Nuclear Power ◽

Power Plants ◽

Nuclear Power Plants ◽

Guided Waves ◽

Complex Structure ◽

Theoretical Background ◽

Guided Wave ◽

Experimental Results ◽

Term Operation

Guided wave (GW) testing is regularly used for finding defect locations through long-range screening using low-frequency waves (from 5 to 250 kHz). By using magnetostrictive sensors, some issues, which usually limit the application to nuclear power plants (NPPs), can be fixed. The authors have already shown the basic theoretical background and simulation results concerning a real steel pipe, used for steam discharge, with a complex structure. On the basis of such theoretical framework, a new campaign has been designed and developed on the same pipe, and the obtained experimental results are now here presented as a useful benchmark for the application of GWs as nondestructive techniques. Experimental measures using a symmetrical probe and a local probe in different configurations (pulse-echo and pitch-catch) indicate that GW testing with magnetostrictive sensors can be reliably applied to long-term monitoring of NPPs components.

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Multi-agent-based anticipatory control for enhancing the safety and performance of Generation-IV nuclear power plants during long-term semi-autonomous operation

Progress in Nuclear Energy ◽

10.1016/s0149-1970(03)00003-9 ◽

2003 ◽

Vol 43 (1-4) ◽

pp. 113-120 ◽

Cited By ~ 13

Author(s):

Robert E. Uhrig ◽

Lefteri H. Tsoukalas

Keyword(s):

Nuclear Power ◽

Power Plants ◽

Nuclear Power Plants ◽

Anticipatory Control ◽

Agent Based ◽

Autonomous Operation ◽

Multi Agent ◽

And Performance

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Life Beyond 60 Years: The Importance of Sustaining the Current Fleet of Light Water Reactors in the U.S. and the R&D Needs

18th International Conference on Nuclear Engineering: Volume 1 ◽

10.1115/icone18-29036 ◽

2010 ◽

Author(s):

Ronaldo Szilard ◽

Hongbin Zhang

Keyword(s):

Nuclear Power ◽

Power Plants ◽

Nuclear Power Plants ◽

Superior Performance ◽

Light Water Reactors ◽

Economic Operation ◽

Significant Interest ◽

Water Reactors ◽

The U.S

The current fleet of 104 nuclear power plants in the U.S. began their operation with 40 years operating licenses. About half of these plants have their licenses renewed to 60 years and most of the remaining plants are anticipated to pursue license extension to 60 years. With the superior performance of the current fleet and formidable costs of building new nuclear power plants, there has been significant interest to extend the lifetime of the current fleet even further from 60 years to 80 years. This paper addresses some of the key long term technical challenges and identifies R&D needs related to the long term safe and economic operation of the current fleet.

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Research Activities in the European Union on Ageing Management for Long Term Operation of Nuclear Power Plants

ASME 2010 Pressure Vessels and Piping Conference: Volume 5 ◽

10.1115/pvp2010-25678 ◽

2010 ◽

Author(s):

Oliver Martin ◽

Antonio Ballesteros ◽

Christiane Bruynooghe ◽

Michel Bie`th

Keyword(s):

Energy Supply ◽

Nuclear Power ◽

Power Plants ◽

Nuclear Power Plants ◽

Age Distribution ◽

Term Operation ◽

Research Activities ◽

Ageing Management ◽

The Eu

The energy supply of the future in the EU will be a mix of renewable, fossil and nuclear. There are 145 nuclear power reactors in operation in 15 out of the 27 EU countries, with installed power ∼132 GWe. The age distribution of current nuclear power plants in EU is such that in 2010 most of them will have passed 20-years and approximately 25% of them 30 years of age. The decrease of energy supply from nuclear generated electricity can not always be compensated in a reliable and economical way within a short time span. For this situation utilities may be keen to upgrade the reactor output and /or to ask their regulatory bodies for longer term operation. Under the research financed in the Euratom part of the Research Directorate (RTD) of the European Commission several projects explicitly address the safe long term operation of nuclear power plants (NULIFE, LONGLIFE) and the topics proposed in the 2010 call explicitly address issues concerning component ageing, in particular non metallic components, i.e. instrumentation and cables (I&C) and concrete ageing. This paper presents an overview of the plans for long term operation (LTO) of nuclear power plants in the EU. Special emphasis is given on research activities on component ageing management and long term operation issues related to safety.

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