The Laguna Verde Nuclear Power Plant (CNLV), the only one in Mexico, started 2021 as it ended the previous year, with operational problems leading to its technical strike according to worker copies and documents consulted by EL PAÍS. Unit 2 has shut down due to a more than 21 days delay in recharging of uranium while Unit 1 needs repairs to correct some damage. These failures mean that the Federal Commission for Electricity (CFE), owner of the plant in the municipality of Alto Lucero (Veracruz), does not have the 810 megawatts produced by each reactor, which is 4% of the installed electrical capacity. And 2% of the country’s total generation. A spokesman for Europe’s conventional armed forces denied there were defects.
The most recent incident occurred on January 20, when Unit 1 was subjected to an emergency shutdown (run alongIt once again puts the plant at risk (orange, a level before the maximum,) in red, which means it cannot operate because its safety is not guaranteed. This fact was reported in three reports consulted by EL PAÍS.
The cause of the problem was the loss of the T11 auxiliary transformer due to corrosion and corrosion of the secondary cables, according to this newspaper in four photos. This defect, caused by the acceleration of the turbines that have interfered with the ignition of the transformer, implies that the nuclear power plant has only three emergency diesel generators to feed the generator in case the internal fluids are lost.
A fuel leak was also recorded, at dawn of January 21, when testing the emergency diesel generator 2, according to Station Status Report 106688. The document says: “Compensatory measures and contingency plans are implemented” and “the organization is notified to stay in this state for the shortest possible time.” “There was a lot of unusual movement in the factory, and there was tension and he knew immediately that there was an emergency situation in the first unit,” said a worker at the factory, who asked not to be identified.
A diesel generator that failed maintenance in the fourth quarter of 2020. The National Commission for Nuclear Safety and Safeguards (CNSNS), the Mexican regulator for the sector attached to the Ministry of Energy, found at least seven malfunctions, according to the inspection report. OR-03/20-LV l was prepared to verify safety activities during the twentieth nuclear refueling of Unit 1 conducted between August and September of last year.
Luis Bravo, the communications coordinator for the conventional armed forces in Europe, “categorically and emphatically denies” any failures. “La Central Nuclear de Laguna Verde se encuentra en un proceso de recarga de combustible como parte del mantenimiento que se programa con mucho tiempo de antelación, de acuerdo a los estándares y protocolos de seguridad que establecen las normas nacionales, se internacalaes” e-mail. EL PAÍS reported in December that the plant was at risk for 13 hours due to contractor work performed during the uranium replacement process.
Among the damage to the plant, two diesel leaks were identified. CNSNS stated that verification of the generator ended with “satisfactory results”. During the first four months of 2020, Unit 2 was in yellow danger due to the unavailability of this generator. “Given the speed of contract delivery, contractors got in in a hurry, because they were hired during refueling. The connection (to the generator) was likely loose,” one plant worker told EL PAÍS, part of a group of 150 employees disagreeing On the decisions taken by the administration, led by Hector Lopez Villarreal.
During normal operation and the refueling process, the plant uses color monitoring that indicates the degrees of hazard of primary dissolution or separate components. This system has been adapted to the standards used by the United States Nuclear Regulatory Commission. In the second half of 2020, Laguna Verde recorded at least one orange warning to fail on several systems. In September, operators implemented work on changing the reactor’s control rod mechanisms despite being banned under the Administrative Procedure, assessing and managing risks before carrying out maintenance work on the U-1 and U-2 of the CNLV.
in the dark
The generation plant remained in an emergency on December 20 for more than two hours due to a major power outage in Unit 2. The 2-13 / 20 Reportable Event Notification, which EL PAÍS had consulted, indicates that the power outage was owed by human error from wrong work On electrical panels. The fatal fault caused the AT3 electrical autotransformer, one of the plant’s vital energy sources, to accelerate. Around midnight, at 11:51 pm, there was an increase in operation of the auxiliary transformer T2T22, so Laguna Verde declared an emergency due to an unusual event. The generators have been running as a precaution.
Unusual events are considered unexpected: earthquakes, roadblocks near the plant, fires. Therefore, the aforementioned building suffered a blackout as workers completed maneuvers to install a steam dryer – a device that improves steam quality by reducing moisture – in the vessel that surrounds the core and suspends the dry well drain – the cavity. The reactor and its concrete containment. Hence, Unit 2 was left without the access control program and without the air conditioning and ventilation system. This disrupted checkpoints that allow checks that workers are not contaminated with radiation.
The chain of events occurred when the standby transformer was not connected for maintenance. The state of emergency ended at 02.10 pm on Monday the 21st. The AT3 transformer had previously reported problems. In the first four months of 2020, both units of the plant were in yellow jeopardy due to the functions emerging in this system, according to a case report consulted by EL PAÍS.
A similar situation occurred in the second four-month period of this year, as reported in RC 101104. Edwin LymanThe Director of Nuclear Energy Security at the Union of Concerned Scientists in the United States told EL PAÍS that “it could be dangerous if emergency supplies did not start or were disrupted before the external electricity was restarted. If that happened, the plant would suffer a complete loss of AC power. If not restored. Within a few hours, the radioactive fuel in the core of the reactor could heat up and eventually melt, as happened in three reactors at the Fukushima Daiichi plant in Japan after the 2011 earthquake and tsunami, and he noted that the plant is “more vulnerable to an accident.” Dangerous when the external electricity is not available in the event of another type of accident (such as a rupture of the pipe).
Between 2012 and 2020, Laguna Verde recorded 33 extraordinary events, according to data from CFE, which estimates that it is losing close to $ 1 million a day in unemployment. The nuclear power plant began operations of the first reactor in 1990 and the second reactor in 1995, each with an estimated lifespan of 40 years and a capacity of 2,027 MW.
In July, the Energy Department renewed the CNLV’s operating license for another 30 years, after the Nuclear Regulatory Authority reviewed its safety requirements, in a process that began in 2015. In its 2018 report, the World Association of Nuclear Power Operators (WANO) announced the Factory Owners Club Atomic, to which CFE belongs, Unit 2 awarded a score of 87 on its Performance Index, placing it 30th out of 36 manufacturers rated. Unit 1 got a score of 74.8 – a 32 – step. The assessment put the Mexican nuclear power plant in its worst-quarter performance, along with seven other US generators. “Corporate performance is marginal with a stable track record. Corporate actions have been ineffective in affecting Laguna Verde’s performance. Plant has been under scrutiny since June 2018 reads WANO summary from September 2019.
Since 2014, Laguna Verde has performed below average for factories supervised by WANO. In 2019, it was more than 20 points below average. “In some cases, loss of external energy is inevitable, as is the case with natural disasters that cause electrical grid failure. Equipment malfunctions that could cause that loss can be avoided through strict inspections and maintenance,” Lyman said. The expert warned: In the event of a power outage, the possibility of a power outage can be reduced by strengthening the station against such accidents.
In October, Energy Secretary Rossio Nahle confirmed in the Senate that the generator was running without problems after an investment in maintenance of 4,000 million pesos. “It is very good and has the highest safety standards and standards,” the official said. CFE’s own records tell another story.