Maintenance of the hot water boiler at the Cofrentes nuclear power plant

Soluciones Integrales de Combustión has carried out maintenance on the hot water boiler at the Cofrentes nuclear power plant, in Valencia. This power plant produces more than 46% of the electricity generation in the Valencian Community, with a production of 9,247 million kilowatt hours in 2020, according to the system operator.

The maintenance work on the hot water boiler at the Cofrentes nuclear power plant carried out by Soluciones Integrales de Combustión has been developed as a task prior to the recharging process of the plant, which will last approximately 35 days, and will end in mid-December. 

The Cofrentes nuclear power plant, owned by Iberdrola, was uncoupled from the national electricity grid last Friday, November 12, to begin its twenty-third refueling, in which it will invest more than 22 million euros.

Activities during recharging

Cofrentes stops its activity every 24 months to refuel. The shutdown is also the period used to supervise and allow the correct operation of the plant, through corrective, preventive, conservative and modified maintenance of the equipment, components and systems of the installation, as well as the surveillance and tests required by the Technical Operating Specifications (ETF).

The objective of the refueling stop is to replace the spent fuel, approximately one third of all the fuel in the reactor core, with a new one, store the one that is withdrawn in pools and relocate two thirds of the fuel that is removed in other positions within the core, to optimize the degree of burning or consumption thereof. Thus, during the recharging process, the plant will replace 228 of the 624 fuel elements that make up the reactor core, so that it has enough fresh fuel in the vessel to tackle a new operating cycle.

In addition, periodic safety inspections and associated preventive maintenance will be undertaken, which can only be addressed with the power station shut down, and 26 design modifications or improvements will be carried out. All these tasks make it possible to guarantee that the plant continues to operate with the best safety and reliability standards.

The Refill Planning team has scheduled the execution of more than 11,000 jobs to ensure that they are carried out with full safety and following the stipulated quality criteria.

The actuation of the recharge consists of the partial unloading of the core to change the 228 elements mentioned, the replacement of 14 control rods and 20 of their actuators.

Other relevant activities to be carried out are the replacement of one of the low pressure rotors of the main turbine, which will be complemented by an inspection of the generator and a general overhaul of the turbine stop and control valves, as well as the milestone of the renewal of the main generation switch for a state-of-the-art model.

Almost half of the Valencian electricity

The plant’s annual production is equivalent to the consumption of more than two million homes and also avoids the emission of some five million tons of CO2 into the atmosphere, thereby contributing to the fight against climate change.

This recharge culminates an operation cycle with a high reliability index, according to the data provided by the company, as the plant has operated 99.5% of the time connected to the grid since the previous recharge in December 2019, which has allowed to guarantee a stable and emission-free electricity supply.

Boiler maintenance activity

Soluciones Integrales de Combustión is a thermal and combustion engineering company focused on improving the reliability and productivity of its clients’ plants. With the aim of adding value, it designs and implements optimal design solutions to increase the performance of the facilities, to adapt them to environmental requirements and achieve energy savings.

The industrial boiler maintenance area, as well as the regular supervision of this equipment, contributes to optimizing operating costs and avoiding failures and damage to the installations and the installation operators. Maintenance in industrial boilers is also aimed at providing the correct operation of the plant, improving the energy efficiency of the facilities and extending the life of the equipment and combustion systems.

The use of industrial boilers is very common in many facilities. They are used either to generate heat or to facilitate the manufacturing process in heating, chemical plants, paper mills, the beverage industry, food, etc.

The maintenance of the hot water boiler at the Cofrentes nuclear power plant is part of its services area. Soluciones Integrales de Combustion Solutions undertakes various types of predictive, corrective, preventive maintenance, zero hours (Overhaul), maintenance in use and regulatory inspections, since some of the equipment installed in thermal power plants (boilers, tanks, storage tanks or fire-fighting installations are subject to rules or regulations of the competent administration that requires these tasks periodically to guarantee the safety of the plant.