Positive feedback from WANO Peer Review
Following recent WANO Peer Review at the Dukovany NPP, TES has noted very positive feedback for workers from the TES Electrical Service and Maintenance Department. WANO experts performed observation during periodic inspection of ELS automatics and 3min check runs of diesel generator operation carried out by TES workers Milan Kasarnik and Jiří Švestka. Both TES specialists were appreciated for professional performance and behaviour, perfect communication and cooperation with operators. They had been interviewed during and at the end of the inspection to clarify detailed questions of WANO observers. Professionally managed tests contributed to positive evaluation of the area and good results of the WANO inspection at the Dukovany NPP. The WANO Moscow Centre team composed of 25 representatives performed the fourth Peer Review to assess the Dukovany NPP operation. International experts inspected and evaluated 10 main areas assessing them against relevant current best practices. Special attention was paid to nuclear safety, operation, maintenance, radiation and fire protection, emergency preparedness as well as to organization of management or education and trainings.
TES presented the results of MELCOR code assessment for Severe Accidents against THAI HR-1 experiment at the NUSIM conference and EMUG meeting
The experts from TES attended Czech conference NUSIM and EMUG (European MELCOR User Group) Meeting. At both events they presented their results of MELCOR code assessment for Severe Accidents against THAI HR-1 experimental test performed on THAI Facility (Germany). Passive Safety Recombiner (PAR) model performance was assessed in severe accident conditions against HR-1 test data. PAR is a safety feature located in the containment of a nuclear power plant and it contributes to hydrogen removal in the containment. Hydrogen is produced during severe accidents and it is one of the most serious threats confirmed for example in frame of Fukushima Dai-Ichi accident. MELCOR code assessment was performed within Czech – Korean joint project „Examination and improvement of mitigation capabilities and strategies of operating PWRs and an APR series PWR against Design Extension Conditions (DEC)“ which is co-financed from TACR in frame of DELTA2 funding. A new in-house methodology for modeling PAR in MELCOR was developed and validated by the experts of Nuclear Safety Department of TES in the framework of above activities.
Joint R&D project of TES and Brno University of Technology with Korean partners – DEC mitigation strategies for PWR and APR GENIII+ reactors
The joint international R&D Project “Examination and improvement of mitigation capabilities and strategies of operating PWRs and an APR series PWR against Design Extension Conditions (DEC)” was launched in January 2021. The following partner institutions and enterprises from the Czech Republic and the Republic of Korea are participating in this project: TES Ltd and Brno University of Technology on the Czech side and FNC Technology Co., Ltd; Korea Hydro & Nuclear Power Co., Ltd. and KEPCO International Nuclear Graduate School on the Korean side. The Project is co-financed by Technology Agency of the Czech Republic (TACR) and by the Korea Institute of Energy Technology Evaluation and Planning (KETEP). The strategies and capabilities for DEC mitigation of both participating countries are expected to be compared for operating nuclear power plants and GenIII+ series plant of APR design in frame of this Project. The review of latest legislation and regulatory trends on DEC, as well as benchmarking of computer codes and analysis methods is also expected to be performed as a part of this Project. The project builds on the long-term cooperation of TES s.r.o. with partners from the Republic of Korea in the field of nuclear energy and nuclear safety.
Complex analysis of the voltage and current of the switchgear input for monitoring of the powered device condition
TES s.r.o. in cooperation with the Brno University of Technology, the Department of Theoretical and Experimental Electrical Engineering, have been working on the project aiming to enable remote evaluation of the connected electrical devices, for example electrical motors, by measuring of the current and voltage waveforms at the power input of the switchgear. The use of the methods for measurement, signal processing, spectral analysis by the fast Fourier transformation and the MCSA analysis (Motor Current Signature Analysis) are used to fulfil above mentioned goals. Project outputs include methods and procedures for regular analysis of measured quantities and the innovation of the software for data analysis. The connected devices, such as large asynchronous motors, requires complex non-destructive diagnostic method of the technical condition which can be performed during operation without need of any interruption. The ability of data monitoring at the switchgear offers a potential for a significant increase of frequency of data measurement which improves the chances for early detection of the change or early stage malfunctions of the connected device. The innovation of the software tools for data processing of a wide range of connected devices is a key instrument for quick and effective detection of changes in measured quantities.
The Memorandum of Understanding between TES and KHNP signed
The next step in the development of further cooperation between TES s.r.o. and the South Korea company Korea-Hydro & Nuclear Power (KHNP) is the conclusion of the Memorandum of Understanding. The Memorandum was signed at the beginning of September during the visit of Mr Jae Hoon Chung, the KHNP President & CEO, in the Czech Republic. This act declares the intention of parties to support joint projects in the area of operation, service and maintenance, research and development and design and engineering of nuclear power plants. The Memorandum envisages joint participation in the construction of new nuclear power units in the Czech Republic as well as abroad.
TES activities at the NPP sites continue as scheduled under the strict preventive measures due to coronavirus pandemic
TES workers carry up in planned activities, despite difficulties caused by coronavirus pandemic. They fully comply with time schedule according to the requirements of our customer (ČEZ, a.s.) in the area of service and maintenance of the electrical and machinery equipment at the NPP Dukovany and NPP Temelín. ČEZ, a.s. has implemented many necessary measures ensuring continuing production and safe operation of both nuclear power plants. Some of them will definitely have a negative economic impact on our company. It is mainly the postponement or even cancellation of some works which in the short term do not significantly affect the operation or safety of the NPP. The reason for such changes is to reduce number of people working in the area of the NPP site. We face some other challenges. For example work overload of the key specialists, difficulties in commuting to workplace or limited number of people during meetings. There is necessary to keep distance and follow all administrative changes. We respect all the measures and strictly observe all the rules. The Unit 3 of the NPP Dukovany is currently undergoing planned outage, other units are at full operation. TES workers provide all standard activities regarding regular service and maintenance of the electrical equipment at all units. In particular, it is the maintenance of the diagnostic and monitoring system for the plant electrical equipment (MSE), transformer monitoring systems (MST) and other relevant subsystems. Our specialists at the Temelín NPP currently participate on the planned outage of the Unit 1.They provide service and maintenance, testing, diagnostic monitoring, measurements and analyses of the plant electrical systems. Among others, the most important works provided by TES during the outage is the inspection of the monitoring and diagnostic systems of turbo-generators, transformers and on-line monitoring system of the plant electrical equipment (NEMES).
TES developed an in-house methodology for modelling Passive Autocatalytic Recombiners in MELCOR
TES experts from the Nuclear Safety Department have developed a methodology for modelling a Passive Autocatalytic Recombiners (PARs) in MELCOR code, which is used in TES for modelling severe accidents. The PARs are located in the containment and are designed to passively remove the hydrogen, which can be released into containment atmosphere during severe accidents and may become a safety threat. The methodology describes how to prepare a model of a specific PAR by arbitrary vendor and how to implement it in the system MELCOR model. The methodology was successfully validated against the data from the experimental facility THAI (Germany).
Nuclear safety assessment of the APR1000 discussed with KEPCO E&C at joint workshop
The experts from Korean company KEPCO E&C visited Třebíč to participate in a workshop, held from 18 to 21 February, 2020 in TES headquarters. The participants addressed the issues of assessment of AMS (Accident Management System) and determination of the source term. These topics are part of the broader project framework, where TES participates in the safety assessment of APR1000 reactor, as this type possibly can be used for the construction of new units in the Czech Republic. The workshop was another example of successfully developing cooperation between TES and Korean partners.
TES experience in discharge measurement of batteries during simulated SBO accident conditions at the IAEA Technical Meeting
TES experts participated in Technical Meeting on the Management of Direct Current Power Systems and Application of New Devices in Safety Electrical Power Systems for Nuclear Power Plants held at the IAEA’s Headquarters in Vienna, Austria, from 2 to 6 December 2019. The topic covered the issues encountered in direct current (DC) safety power systems due to accelerated ageing of batteries and the use of new devices and technology including power electronic and smart devices. Mr. Frelich presented TES field experience with the discharge measurement of batteries during simulated station blackout (SBO) accident conditions.
TES in negotiations with South Korea partners about cooperation in R&D
South Korea KHNP (Korea Hydro& Nuclear Power) and KEPCO E&C representatives visited TES headquarters in Třebíč on 5 September, 2019. Both parties informed about their activities in nuclear industry and discussed areas of possible future cooperation. Among all bidders, South Korea ´s KHNP is considered to have the best references to win the competition for the supplier of additional nuclear units in Dukovany NPP and now is in search for local sub-suppliers. Except future construction of nuclear power units KHNP is calling on know- how of Czech engineering and industrial companies for other KHNP projects (KHNP operates 24 reactors and 9 more is under the construction). Discussions with KHNP representatives opened the way for TES to further cooperation in the research and development of new technologies and interconnections with KHNP partners.