Robustness of Electrical Systems of Nuclear Power Plants in Light of the Fukushima Daiichi Accident (ROBELSYS). Workshop Proceedings, Paris, France, 1-4 April 2014 - Robustness of Electrical Systems of NPP's in Light of the Fukushima Daiichi Accident. ROBELSYS Workshop Proceedings
Description
The March 2011 accident at Fukushima Daiichi triggered discussions about the significance of electrical power hazards and their treatment in safety analyses. In order to address these issues and provide relevant conclusions and recommendations to CSNI and CNRA, the Robustness in Electrical Systems (ROBELSYS) Technical Working Group was established in 2012 under the leadership of the Institut de Radioprotection et de Surete Nucleaire (IRSN) of France. The purpose of the ROBELSYS Technical Working Group was to organize an international workshop to identify and discuss the lessons learned from the Fukushima Daiichi accident. The workshop was focused on the provisions taken by various countries concerning national requirements and modifications to the plant designs in order to enhance the robustness of electrical systems, especially the protection against extreme external hazards. The ROBELSYS workshop was held at the OECD Conference Centre in Paris in April 1-4, 2014. A total of 105 participants attended the workshop representing industry and government organisations from 25 countries, as well as international organisations. A total of 34 technical presentations were given in seven sessions as follows: - 1: National Programmes on Evolution of Onsite and Offsite Electric Power Systems; - 2: Role of Electric Power in Severe Accident Management; - 3: Requirements for Robustness of Onsite Electric Power Systems; - 4: Simulation of Transients within NPP Plant Distribution Systems; - 5: Requirements for Equipment Used for Emergency Response; - 6: Margin Assessments for Modern Power Electronics; - 7: Digital Components in Power Systems. Items addressed in the workshop included: - Review of the lessons learned from the Fukushima accident concerning the robustness of electrical systems; - Review of the provisions already taken or planned after the Fukushima accident, regarding the sources, the distribution systems and the loads, and documenting the technical basis for these improvements; - Review of the possibilities to connect sources very close to the loads; - Review of the protection of distribution systems against external hazards. At the end of each session, a panel session was held allowing for more detailed discussions on any of presentations in that session. On the last day, a general discussion session concluded the workshop. Based on the discussions a strong interest for continuing efforts after this ROBELSYS workshop was expressed by the participants of the workshop, leading the task group to recommend launching a more permanent international working group. The support to the identification of the need for new specific international standards was also recommended regarding: system and component requirements for beyond design basis external events, diversity in the onsite electrical power systems, relaxation of electric power protection features used in emergency situations, qualification of existing and portable components to cope with AC station blackout. The following issues were highlighted by the participants as topics of concern which needed further development: - Simulation of electrical transients in general and in particular of asymmetric 3-phase electrical faults (one/two-open-phase issue) - Development of standardised transient voltage wave forms for use in the qualification process of onsite electrical equipment. (These wave forms may replace or supplement the currently used lightning and switching impulse test wave forms.) - Reliability and robustness of new battery designs regarding SBO scenarios. It was also noticed that it would be beneficial to continue information sharing with several other NEA working groups and in particular with the Working Group on Risk Assessment (WGRISK) of CSNI with which several topics for enhancing synergies have already been identified
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Additional details
Publishing Information
- Imprint Pagination
- 394 p.
- Report number
- NEA-CSNI-R--2015-4
Conference
- Title
- ROBELSYS Workshop on the Robustness of Electrical Systems of NPP's in Light of the Fukushima Daiichi Accident
- Dates
- 1-4 Apr 2014
- Place
- Paris (France)
INIS
- Country of Publication
- Nuclear Energy Agency of the OECD (NEA)
- Country of Input or Organization
- Nuclear Energy Agency of the OECD (NEA)
- INIS RN
- 46066605
- Subject category
- ENGINEERING; GENERAL STUDIES OF NUCLEAR REACTORS;
- Resource subtype / Literary indicator
- Conference
- Is Lead record
- Yes
- Quality check status
- Yes
- Descriptors DEI
- AC SYSTEMS; AVAILABILITY; COMPUTERIZED SIMULATION; DC SYSTEMS; ELECTRIC GENERATORS; ELECTRICAL TRANSIENTS; EMERGENCY PLANS; EQUIPMENT PROTECTION DEVICES; NUCLEAR POWER PLANTS; OUTAGES; REACTOR SAFETY; RECOMMENDATIONS; REDUNDANCY; RELIABILITY; SAFETY MARGINS; VULNERABILITY;
- Descriptors DEC
- ELECTRICAL EQUIPMENT; ENERGY SYSTEMS; EQUIPMENT; NUCLEAR FACILITIES; POWER PLANTS; POWER SYSTEMS; SAFETY; SIMULATION; THERMAL POWER PLANTS; TRANSIENTS; VOLTAGE DROP;