Reducing radiation exposure in nuclear power plants by appropriate maintenance policies

1981 ◽  
Vol 8 (1) ◽  
pp. 31-39
Author(s):  
H. Gehring ◽  
U. Pachow ◽  
H.-J. Zimmermann ◽  
H.J. Rokohl
Keyword(s):  
Radiation Exposure ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Maintenance Policies

The Development of Radiation-Resistant RF Tags for Use at Nuclear Power Plants

2013 ◽  
Author(s):  
Nobuyuki Teraura ◽  
Kunio Ito ◽  
Naoki Takahashi ◽  
Kouichi Sakurai
Keyword(s):  
Radiation Exposure ◽  
Radiation Damage ◽  
Radio Frequency Identification ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Automatic Data ◽  
Radiation Resistant ◽  
Rf Tags ◽  
Rf Tag

RF tags based on RFID (Radio-frequency Identification) technology have been widely used in various fields including power plant construction and maintenance for the purpose of improving the identification and traceability of the many components in the facility. To date, various types of tags have been developed, including tags that are resistant to chemicals or high-temperature environments, which are used in specialized fields. When considering widespread use of RF tags in nuclear power plants, there is a concern about the effects of radiation on the RF tags, because the data stored in the tag may receive radiation damage, resulting in corruption of data. Here, we describe a newly designed RF tag that achieves resistance to radiation damage by attaching a radiation shield layer and incorporating automatic data-correction software. This radiation-resistant RF tag has been tested under real radiation exposure fields to verify the intended radiation-resistant functions. It is expected that the use of these radiation-resistant RF tags with a data reader and database system will increase the capabilities of RF tags applied to nuclear power plants and it is also expected to lead to reductions in worker radiation exposure doses.

scholarly journals Multi-state Risk-Based Maintenance Analysis of Redundant Safety Systems Using the Markov Model and Fault Tree Method

2021 ◽  
Vol 9 ◽  
Author(s):  
F. Mohammadhasani ◽  
A. Pirouzmand
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Fault Tree ◽  
System Level ◽  
Aging Effects ◽  
Maintenance Activities ◽  
Maintenance Policies ◽  
Safety Systems ◽  
Tree Method

The risk-based maintenance strategy has received special attention in the safe operation of nuclear power plants. Simultaneous quantification of the positive and negative effects of maintenance activities and components degradation effect makes it possible to accurately evaluate the risk criterion for safety systems of nuclear power plants. However, it is difficult to integrate the effects of maintenance and components degradation into the standard reliability approaches. A straightforward approach for considering components degradation and different maintenance policies is to make use of Markov maintenance models. In this article, the effectiveness of maintenance activities (including changes in the surveillance test intervals and alteration in the different maintenance policies) on the components unavailability with considering aging effects is quantified using Markov maintenance models and then by coupling these models and the fault tree method, the risk measure is upgraded from the component level to the system level. The proposed models are applied to evaluate the unavailability of two safety systems of VVER-1000/V446 nuclear power plants as case studies. The results show that the Markov method due to its multi-state nature is effective in the conservative evaluation of risk measures so that the unavailability computed by the coupling process is higher than the original unavailability (calculated by system fault tree using PSA data of nuclear power plants) for all maintenance policies. In addition, this study illustrates that the developed Markov maintenance models could be applied to the large-scale whole plant level and provides a proper transition from the classical PSA methods to new techniques. This approach integrates the effects of maintenance strategies and components degradation. Also, it provides a practical and a more accurate tool to determine the technical specification of a real nuclear power plant from the risk point of view.

Sign in / Sign up

Export Citation Format

Share Document