Support for outage optimization at Paks nuclear power plant

Background and objective of the project

MVM Paks NPP had a strategic goal to enhance availability and operational safety of the plant. In alignment with this goal, the plant initiated an outage management development project. The project was initiated to develop technical, technological, and organizational aspects focused on reducing the duration of outages and ensuring that tasks are carried out reliably and without delays, with safety as a priority. Additionally, the project aimed to identify optimal organizational structures and process improvements to support more effective outage planning and execution.

Fortum, with its extensive operational experience from its own nuclear operations, was selected to provide expert support for this initiative. The load factors of the Loviisa nuclear power plant have consistently been high on an international scale throughout its history. In 2024, the load factor of the Loviisa power plant was 88.3. The load factor of Loviisa 1 was 86.6% and of Loviisa 2 was 90.0%.

Scope of work

Outage management and optimization require detailed analysis in several areas. The successful execution of outages results from effective organization, well-planned maintenance strategy, effective work planning, and a thorough understanding of operations. Optimized performance is also achieved through the systematic collection of lessons learned throughout the plant's lifetime and executed outages. In this assignment, Fortum experts supported Paks NPP by presenting various topics in expert workshops and by answering the detailed questions regarding the outage management. The overall target was to leverage the practical insights and to open up success factors in Loviisa NPP's optimized outages. During the discussions, differences between the plants were also examined and analysed. The discussions were prepared by proving the answers to the pre-questions via email, followed by in-depth discussions during the workshops and additional deep-dive video meetings.

The following topics were included and discussed in the workshops during the assignment:

• Maintenance strategy and lifecycle management at Loviisa NPP, including an overview of the organization, maintenance dependence on Plant Lifetime Management, and the optimized maintenance concept. Also in-service-inspections including the main component inspection intervals in different outages were introduced.
• Annual outage strategies in Loviisa NPP including the types of outages and main works, as well as planning horizons (long-term, mid-term, and short-term) at Loviisa NPP.
• Planning and execution of annual outages, including preparation, scheduling, pre-planning, work processes during the annual outage and post-evaluation following the annual outage
• Work management, including the number of work orders in different outages.
• Annual outage organization including the roles and responsibilities both in the planning phase and during the execution of the outage
• Outage KPIs and feedback mechanisms
• Unexpected issue and risk management during outage
• Annual outages from Operations perspective including the review of shutdown and start-up activities:
  • Operations organization
  • Cleaning and soft decontamination of primary circuit
  • Conservation and passivation of secondary circuit
  • Checks related to operational state change in startup
  • Startup tests
  • Safety system tests
  • Pressurizer Safety and Relief Valve Tests
  • Primary circuit and steam generator tightness tests
  • Steam generator drainage, warm up method and timing during startup
  • Criticality tests
  • Operational tests after critical tests
  • Clearance Management and planning prior the outages

Outcome of the assignment

The project enabled knowledge transfer from Fortum to MVM Paks, providing practical insights, tailored recommendations, and international benchmarks to enhance outage planning and execution, as well as to improve internal processes and organization for future outages.

Comment from the client:

As part of an international cooperation, the project significantly contributed to improving the efficiency of planning, preparing and implementing outages. In addition, by taking technological differences into account, the joint work provided inputs in discovering review areas of the unit shutdown and startup activities and their sequence. The project brought valuable information to the client on effective nuclear unit operation including allocation of organizational and personal roles and responsibilities for outage planning, management, work execution and handling of clearances.