ELECTRICAL POWER SUPPLY
Reliable electrical power supply, in particular to the safety systems
A dependable supply of electrical power is needed to operate the safety systems' active components and the operational systems besides ensuring the functionality of the related monitoring, control and protection equipment as credited in the safety analyses.
In all life cycle stages of a nuclear facility ranging from planning through installation and operation right up to decommissioning, TÜV NORD Nuclear provides support in designing, establishing and ensuring the functionality of the electrical power supply system. The spectrum of TÜV NORD Nuclear services includes the assessment of the electrical power supply system, supervisory inspections, reviews of design documents, as well as tests on site.
Electrical power supply system
Requirements concerning the design and operation of electrical equipment and aspects related to process engineering are defined in codes and standards governing non-nuclear as well as nuclear technology. The electrical power supply system essentially comprises the items mentioned next:
- Mains connection system including primary, reserve and standby connections
- Emergency power supply system with diesel generators
- Power distribution including switchgear, protective mechanisms and cable systems
- Uninterruptible power supply system with rectifiers, inverters and batteries
Also indispensable for reliable power supply are effective earthing and lightning protection systems which appropriately limit the effects of atmospheric and switching excess voltages as well as consequential electromagnetic effects (as defined by electromagnetic compatibility standards) on the equipment.
TÜV NORD Nuclear performs the following activities for all of the facilities and systems mentioned above:
- assessments of concepts and evaluations of the design of the electric power supply system as well as the earthing and lightning protection system on the basis of component and material specifications
- computer-aided short-circuit and load-flow calculations; evaluation of selective fault elimination (graded protection plan)
- design reviews of the suitability of the components intended for the electric power supply system and earthing / lightning protection systems; reviews of the submitted quality assurance test schedules
- participation in construction and acceptance inspections
- participation in recurrent in-service inspections (ISI)
- assessment of modifications and maintenance measures
- monitoring of plant operation and evaluation of events and incidents that must be reported
- assessment of the licensee's regulations (operation and emergency procedures)
- assessment of ageing management
Based on their long-term years of experience as consultants, the TÜV NORD Nuclear experts do not only provide services on behalf of the regulator, but they also offer consultancy on the above matters and provide services in preparing the relevant documents.

