Inspections at the Loviisa nuclear power plant

STUK carries out inspections to oversee the operation and use of the Loviisa nuclear power plant. The periodic inspection programme covers safety management, main operational processes, procedures and technical acceptability of systems. 

STUK draws up a plan for the inspection, setting out the subject of the inspection and any preparatory actions required of the licence holder. The result of the inspection and the resulting requirements are set out in the inspection report.

Periodic inspections

Below are summaries of the inspections carried out by STUK in year 2024 in accordance with the periodic inspection programme for the Loviisa nuclear power plant.

Safety functions, 7–8 October 2024

The topic of the 2024 inspection was fuel cooling and residual heat removal, for which the systems selected for the inspection were the cooling system of the reactor building’s fuel pools and the parts of the plant make-up water system which take care of the water supply to safety significant systems. The inspection also reviewed how the persons responsible for the systems monitor use of the external and internal operational experience in their work.

The status of the systems in the inspection area was good. Periodic inspections under the Operational Limits and Conditions (OLC) have been carried out appropriately in both systems. The instructions related to the systems are also up-to-date. The cooling system of the fuel pools is undergoing modifications to improve its condition. The events of the plant and those of other plants are used as operating experiences.

No requirements were made on the basis of the inspection. Based on the inspection, this area meets requirements.

Plant maintenance, 10–11 October 2024

The inspection assessed the adequacy of automation maintenance, quality control and ageing management resources and the training.

In addition, the inspection covered the ice condenser systems inside the containment building needed in accident situations from the point of view of their operating condition. In particular, the number of fault repairs, the spare parts situation and the planning situation of modifications and maintenance work were inspected. Based on the inspection, it can be determined that the systems are operational.

Based on the inspection, STUK states that the inspected entity is at a good level. The work of updating the time-limited analyses and qualifications to the plant’s ageing management database (LOAM) has progressed, but the import of the device data of the two systems to the database was in progress at the time of the inspection. STUK required Fortum to complete the update work by 31 October 2025.

Annual maintenance, 4 August–2 October 2024

The inspection of the Loviisa plant’s annual outage assessed and verified the activities related to the safe implementation of the annual maintenance and modifications of the plant units. Several inspectors from different technical areas participated in the inspection, carrying out site tours, monitoring the activities, interviewing personnel and monitoring progress of the planned work. During the annual outage, special attention was paid to the management of work-related safety measures, which is the theme of Loviisa’s annual maintenance and which the facility has tried to develop based on the experiences of the recent years, for example, by means of thematic investigation.

The other targets of this year’s inspection included:

• Kick-off meetings for annual maintenance work and taking into account the risk significance of the work related to nuclear safety.
• Radiation protection procedures and radiation levels during annual maintenance.
• The modifications include, in particular, the replacement of one steam generator blow-down line of LO2, maintenance work on the main circulation pumps and the replacement of the cover seals, as well as the replacement of one LO1's emergency diesel 4 engine and generator.
• Adequacy of work order feedback data in electrical and automation work from the point of view of operating experience.
• The Point of No Return (PONR) procedure piloted in 2024, which systematically monitors the progress of projects and alteration work and, thereby, aims to ensure readiness for implementation in the annual maintenance.
• Procedures and practices related to the use of safety-classified supplies (TLTA) which ensure that incorrect chemicals are not used, the lifespan of power plant components is not reduced and a negative impact on, for example, the water chemistry of the primary circuit is not caused.
• Fire protection arrangements at the plant.
• Loose part management.
• Waste management, especially the operations of the waste packaging facility and plastic coating of work sites.

During the annual maintenance, no deviations were found in Fortum's operations that would have required immediate intervention from STUK. On the basis of the inspection, it can be concluded that Fortum's annual maintenance activities comply with the requirements.

Based on the inspection, STUK presented several observations for the further development of operations in future annual maintenance concerning, for example, kick-off meetings, the management of work-related safety measures, the implementation of procedures for safety-classified materials and work orders feedback. Based on the inspection, STUK required Fortum to submit an assessment and any related measures regarding observations concerning the kick-off meetings for information.

Effects of power control on the safe operation of the plant, 4 June 2024

Regular power adjustment is a new mode of operation in the electricity production of nuclear power plants in Finland, and the Loviisa plant was not originally designed for this type of operation. The aim of the inspection was to find out how regular power adjustment affects and challenges operations and the plant in a technical sense, and how Fortum has assessed possible long-term effects and risks.

Based on the inspection, the power adjustment of the Loviisa plants has been carried out according to requirements and with due consideration for safety. Fortum’s internal investigations related to power adjustment in terms of fuel, use and chemistry, as well as the use of external operating experiences, have ensured that the organisation is sufficiently prepared to implement regular power adjustment safely.

No faults resulting from power adjustment have been detected in Loviisa. Load monitoring and fatigue analyses conducted as part of the plant’s ageing management support the identification of potential risks over the long term. Furthermore, the power adjustment has not caused any deviations in the chemical parameters, and the power adjustments have not affected the growth or migration of activated corrosion products.

While the Loviisa plant still has only a little operating experience with power adjustments, Fortum has utilised the collected experiences well and developed the instructions and operations based on them.

Organisational factors, 5–7 June 2024

The topics discussed in the inspection included organisational changes in the management of investments and modifications, practices for ensuring a good safety culture among suppliers, and groups and forums evaluating the operations and safety of the Loviisa power plant.

Based on the inspection, STUK finds that the licensee has prepared for the planning and implementation of future investments by organising itself appropriately. Safety is taken into account when justifying investment proposals and in decision-making at both power plant and group level. According to analyses, the organisational change of the maintenance technology unit carried out a year ago has achieved the goals set for it.

To ensure a good safety culture among suppliers, progress has been made in developing practical procedures and establishing them in operations. The interaction between different parties in the organisation has been increased, but overall responsibility and coordination in terms of ensuring a good safety culture among suppliers has not been defined, which can slow down development.

The operations and safety of the power plant are discussed and assessed in a diverse and independent manner in many different forums. Recommendations and observations are raised from these forums for management to discuss and make decisions. The inspection did not provide STUK with a clear picture of which party or person is responsible for the assessment activities and their development as a whole. In its supervisory activities, STUK monitors the direction in which the assessment functions formed by the groups and forums are developing and how effective they are.

No requirements were made on the basis of the inspection. The power plant and the licensee’s operations meet the requirements of legislation within the topic of the inspection.

Safety design, 11–12 June 2024

The inspection covered configuration and requirement management procedures and instructions using pre-selected examples. During the inspection, procedures were verified using the records and documents in the systems.

STUK does not present any requirements on the basis of the inspection. According to the inspection, the instructions are up-to-date and the procedures meet the set requirements for key parts. The development of a template for requirement management plans was considered a positive observation. The inspection identified the need for further specification of the instructions and the recording of interpretations of official requirements to ensure traceability as potential development areas.

Operating experience feedback, 21–22 May 2024

During the inspection, STUK investigated how Fortum’s operating experiences are handled and taken into account in maintenance. STUK also examined Fortum’s procedures for assessing the success of learning from its operating experiences and the main results of the assessments.

Based on the inspection, Fortum meets these requirements. The maintenance staff of the Loviisa nuclear power plant receive a good deal of information about new operational events and discuss the events and the lessons learned. In STUK’s view, Fortum has taken care of the dissemination of operating experience information to the organisation’s various functions. Fortum also uses various methods to ensure that the operating experience procedures are used to learn and achieve results.

Power plant waste, 7–8 May 2024

The inspection focused on the operations of the solidification plant (LOKIT), the processing and disposal of nuclear and radioactive waste generated elsewhere in Finland enabled by the renewed operating licences, and waste management procedures in the management of contamination and minimization of radiation doses.

There have been minor changes in personnel during the last two years, and STUK found that the resources were sufficient. The instructions are mostly up-to-date and the necessary update needs have been identified. Based on the inspection, development activities are carried out systematically and extensively. For example, several development projects are underway in waste management to reduce the amount of waste. These projects include an active metal melting project and the development of emptying procedures for resin tanks. A great deal of development work related to the instructions and process has been carried out at LOKIT, and an investigation into the modernization of equipment has started. Fortum also processes radioactive waste from other sources, such as the FiR 1 research reactor. As the final safety analysis report (FSAR) contains old information regarding LOKIT, STUK required updates to the LOKIT-related chapters of the FSAR. The processing of external waste has not yet been sufficiently taken into account in the safety analysis report.

Based on STUK’s inspection, the radiation protection procedures and plans are adequate. The change project for the disposal concept of the service waste facilities (HULMU) involves structural improvements to the existing facilities, in connection with which waste drums will be moved from one facility to another. The radiation protection plan for the project is comprehensive, but the air discharge control system of the power plant waste facility will require modernization at some point. STUK will supervise the progress of the matter through its continuous monitoring.

Based on the inspection, Fortum’s operations were found to comply with the requirements, but some chapters of the final safety analysis report and instructions need to be updated.

Mechanical technology, 7 May 2024

During the inspection, STUK assessed the condition of the nuclear power plant’s mechanical equipment and structures and reviewed the status of ongoing development work.

The shaft calculation software used for valve actuator sizing is being updated by January 2025. Fortum is also running a distortion calculation development project (SÄRKI), which at least so far has consisted mainly of a thesis on the subject.

In recent years, the causes of leaks detected in the double seals of the main circulation pumps and evaporator collectors have been systematically investigated. With regard to double seal leaks, new sealing options are being tested and cleaning methods are being investigated. The pumps in the emergency cooling and emergency injection systems have functioned well and the maintenance measures are sufficient.

On the basis of the inspection, STUK did not make any requirements. Fortum continues to develop its valve calculation software. STUK monitors Fortum’s seal and pump maintenance measures.

Security arrangements – information security, 10 April 2024

The inspection concerned the information security of the plant in accordance with the focus areas of the inspection.

As a conclusion to the inspection, STUK finds that, in terms of information security, the licensee's information security management system, available resources, competence and the training and exercise system are appropriate and sufficient at the Loviisa nuclear power plant. Good practices related to continuity management and cooperation, for example, were discovered in the inspection.

The licensee also has plans to develop the plant systems in accordance with the principle of continuous improvement in modifications and development projects, taking information security into account. STUK continuously monitors these matters as part of its usual activities.

Security arrangements – physical protection, 8–9 April 2024

The inspection focused on the plant’s security arrangements that are considered to include structural, technical, operational and organisational arrangements to detect, delay and prevent illegal or unauthorized activities.

As a conclusion to the inspection, STUK found that, in terms of security arrangements, the licensee's human resources, competence, training and exercise activities and the up-to-dateness and extent of the instructions at the Loviisa nuclear power plant are appropriate and sufficient. With regard to external operating experiences, there are some special characteristics concerning security arrangements, but the licencee actively utilizes the experiences gained in different ways and implements them in practice where applicable.

A number of good practices were detected during the inspection. For example, Fortum carries out the assessment of security arrangement risks using various procedures and, according to STUK’s observations, the risk assessment measures are very active with regard to factors such as geopolitical risks. The licensee also has sufficient plans for the continuous improvement of security arrangements to ensure the safety of the Loviisa power plant. Modifications related to security arrangements and other development areas aimed at this are proceeding systematically.

No requirements were made on the basis of the inspection. STUK monitors the progress of matters recorded as observations as part of its normal supervision.

Radiation protection, 9–10 April 2024

The measurement of radiation was the main theme of the radiation protection inspection in 2024. The inspection examined the operating condition of fixed and portable radiation measurement devices. Based on the inspection, STUK concluded that the power plant’s radiation measurement systems are in order, and Fortum has carried out a comprehensive survey of the functionality of the measuring devices and the status of spare parts. Based on the surveys, Fortum has launched projects to ensure the functionality of the radiation measurements for the coming years.

The inspection also reviewed the use of radiation in accordance with the safety licence and the related instructions and operations. The inspection focused in particular on the storage procedures, accounting, quality assurance and safety assessments of radiation sources at the Loviisa power plant. Other topics of the inspection included the utilization of external operating experiences, the implementation of the ALARA programme of measures to keep radiation doses as low as possible and other current measures to develop radiation safety.

In conclusion, STUK found that Fortum’s operations relevant to the topic of the inspection are appropriate and that no significant deviations were identified during the inspection. However, the accounting of unsealed sources related to the use of radiation was required to be brought up to date.

Fire protection, 26–27 March 2024

The 2024 fire prevention inspection at the Loviisa nuclear power plant focused on the plant’s structural, active and operational fire prevention arrangements. The inspection assessed Fortum’s fire prevention practices, such as the monitoring and maintenance of equipment and system functionality as well as the use of external operating experiences.

Some of the positive observations highlighted by STUK included the development of personnel through new recruitments and the development of fire door management and inspection procedures.

Overall, the fire safety of the plant has been managed well, and STUK did not present any requirements based on the inspection. The inspection result describes Fortum’s commitment to maintaining and developing fire protection.