Primary contention 12RU1 radiological control

In the primary contention of the Laguna Verde central reactors those are located the main components and control and safety systems related directly with the reactor vessel. Space, accesses, location, maneuvers, armor-plating, movements of components and radiological conditions require of a constant attention to maintain the control of the activities during a fuel reload period. Knowledge, analysis, strategies and attention to the detail in the preparation stages and execution of the fuel reload are fundamental to sum up the objectives. The reload stop 12 of the Unit 1, it required a specific attention in the radiation source due to the addition of noble metals and hydrogen to the vessel internals that generated an increment in the soluble elements of Cobalt and that it was reflected in the radiation fields in the primary contention. Movement of armor-plating of the structures of the biological armor-plating demand to establish new strategies in the control of activities for the next fuel reloads. The analysis and control of the relief valves safety of the reactor vessel, of the exchange of the activation mechanisms of the control bars, as well as of the isolation valves of main vapor and of flow control valves of the reactor recirculation system, its required of a particular attention due to their particular radiological environment, in a brief time space. The importance of this work is located in the detail of critical activities to fulfill the established goals, with successes that can be optimized, and improvement areas that require of investigation and analysis for the implementation of new technologies tend toward to the dose optimization. The reload stop 12 of the unit 1 conclude with 2.43 Sv-person in a period of 27.5 days. (Author)