scholarly journals TRITIUM - A Quasi Real-Time Low Activity Tritium Monitor for Water

2020 ◽  
Vol 225 ◽  
pp. 03008
Author(s):  
C.D.R. Azevedo ◽  
A. Baeza ◽  
M. Brás ◽  
T. Cámara ◽  
C. Cerna ◽  
...  

Tritium is released abundantly to the environment by nuclear power plants (NPP), as a product of neutron capture by hydrogen and deuterium. In normal running conditions, released cooling waters may contain levels of tritium close to or even larger than the maximum authorised limit for human consumption (drinking and irrigation). The European Council Directive 2013/51/Euratom requires a maximum level of tritium in water for human consumption lower than 100 Bq=L. Current monitoring of tritium activity in water by liquid scintillating method takes about two days and can only be carried out in a dedicated laboratory. This system is not appropriate for real time monitoring. At present, there exists no available detector device with enough sensitivity to monitor waters for human consumption with high enough sensitivity. The goal of the TRITIUM project is to build a tritium monitor capable to measure tritium activities with detection limit close to 100Bq=L, using instrumentation technique developed in recent years for Nuclear and Particle Physics, such as scintillating fibres and silicon photomultipliers (SiPM). In this paper the current status of the TRITIUM project is presented and he results of first prototypes are discussed. A detector system based on scintillating fibers read out either photomultiplier tubes (PMTs) or silicon photomultiplier (SiPM) arrays is under development and will be installed in the vicinity of Almaraz nuclear power plant (Cáceres, Spain) by the fourth term of 2019.

2021 ◽  
Author(s):  
Yuhang Zhang ◽  
Zhijian Zhang ◽  
He Wang ◽  
Lixuan Zhang ◽  
Dabin Sun

Abstract To ensure nuclear safety and prevent or mitigate the consequences of accidents, many safety systems have been set up in nuclear power plants to limit the consequences of accidents. Even though technical specifications based on deterministic safety analysis are applied to avoid serious accidents, they are too poor to handle multi-device managements compared with configuration risk management which computes risks in nuclear power plants based on probabilistic safety assessment according to on-going configurations. In general, there are two methodologies employed in configuration risk management: living probabilistic safety assessment (LPSA) and risk monitor (RM). And average reliability databases during a time of interest are employed in living probabilistic safety assessment, which may be naturally applied to make long-term or regular management projects. While transient risk databases are involved in risk monitor to measure transient risks in nuclear power plants, which may be more appropriate to monitor the real-time risks in nuclear power plants and provide scientific real-time suggestions to operators compared with living probabilistic safety assessment. And this paper concentrates on the applications and developments of living probabilistic safety assessment and risk monitor which are the mainly foundation of the configuration risk management to manage nuclear power plants within safe threshold and avoid serious accidents.


Author(s):  
Sangmyeon Ahn ◽  
Jungjoon Lee ◽  
Chanwoo Jeong ◽  
Kyungwoo Choi

We are having 23 units of nuclear power plants in operation and 5 units of nuclear power plants under construction in Korea as of September 2012. However, we don’t have any experience on shutdown permanently and decommissioning of nuclear power plants. There are only two research reactors being decommissioned since 1997. It is realized that improvement of the regulatory framework for decommissioning of nuclear facilities has been emphasized constantly from the point of view of IAEA’s safety standards. It is also known that IAEA will prepare the safety requirement on decommissioning of facilities; its title is the Safe Decommissioning of Facilities, General Safety Requirement Part 6. According to the result of IAEA’s Integrated Regulatory Review Service (IRRS) mission to Korea in 2011, it was recommended that the regulatory framework should require decommissioning plans for nuclear installations to be constructed and operated and these plans should be updated periodically. In addition, after the Fukushima nuclear disaster in Japan in March of 2011, preparedness for early decommissioning caused by an unexpected severe accident became important issues and concerns. In this respect, it is acknowledged that the regulatory framework for decommissioning of nuclear facilities in Korea need to be improved. First of all, we focus on identifying the current status and relevant issues of regulatory framework for decommissioning of nuclear power plants compared to the IAEA’s safety standards in order to achieve our goal. And then the plan is established for improvement of regulatory framework for decommissioning of nuclear power plants in Korea. It is expected that if the things will go forward as planned, the revised regulatory framework for decommissioning could enhance the safety regime on the decommissioning of nuclear power plants in Korea in light of international standards.


Author(s):  
William Server ◽  
Timothy Hardin ◽  
Milan Brumovsky´

The International Atomic Energy Agency (IAEA) has had a series of reactor pressure vessel (RPV) structural integrity programs that started back in the 1970s. These Coordinated Research Projects most recently have focused on use of the Master Curve fracture toughness testing approach for RPV and other ferritic steel components and on the issue of pressurized thermal shock (PTS) in operating pressurized water reactors. This paper will provide the current status for these projects and discuss the implications for improved safety of key ferritic steel components in nuclear power plants (NPPs).


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