[en] The experience which this document wants to present, describes the work being developed by IBERDROLA Ingenieria y Construccion, for the Laguna Verde plant in Mexico, owned by the Federal Electricity Commission (CFE). This generation plant consists of two light boiling water type units (BWR) design by General Electric in the 80's. The objective of this project is to perform the modifications on the thermal cycle of the plant required by an Extended Power Up-rate, to achieve a safe and reliable operation of the plant at 120% of its original thermal power, whilst upgrading and renovating plant equipment and installations to achieve a license renewal from 40 to 60 years of operation The consortium formed in 97% by IBERDROLA Ingenieria y Construccion SAU and in 3% by ALSTOM Mexicana, S.A. de CV, was awarded the contract in an international bid, competing against General Electric and Siemens. The project began in March 2007 and is scheduled to finalize in December 2010. At this point the work carried out include modifications of the main condenser replacement, moisture separator reheaters (MSR's) and feedwater heaters no. 5 and 6 in the two units, therefore having executed two out of four scheduled outages. The scope, development and organization of this project, whose basic elements include the design, engineering, training, supply of equipment, dismantling, installation, testing, commissioning, treatment and delivery of radioactive waste generated during the project implementation to CFE, is aimed to ensure a safe and reliable operation of the plant under the new conditions of increased thermal power of the reactor, with a thermal cycle optimized so that the gross power of the generator increase from the current 686.7 MWe to a value of 817.1 MWe in both units. An Extended Power Up-rate means an opportunity to modernize equipments, to improve maintenance, to get a better plant knowledge and to motivate the employees facing a challenging project. This project, being the biggest foreign nuclear contract awarded to a Spanish company, demonstrates our ability to handle challenging projects which have impact on countries' growth, both in the field of productivity and technical development. It also demonstrates client's commitment to the long term development of nuclear energy, a clean and non contaminating energy, free of CO₂ emissions. Other advantages of the EPU: - Generates significant economic value in the short term, with a very competitive marginal price per kWh in comparison with other technological alternatives - Involves a comprehensive review of plant design, which allows to evaluate and confirm margins in front of the regulatory organism The following are some of the key success factors of an outage: - Implementation of lessons learned during the previous outage; - Detailed and realistic planning of the modification packages activities; - Establishment of contingency plans; - Coordination between the customer and IBERDROLA teams; - Maximization of pre outage work during operation: Planning all work that can be done during operation; - Re-engineering of equipment installation procedures, based on lessons learned. (authors)