Jacobo de las Alas-Pumariño

[Jacobo de las Alas-Pumariño @jacobo_dlasAP]

@knightmayel Cuéntanos cómo va la cosa por favor

[Operador Nuclear @OperadorNuclear]

¿Qué ocurre en las centrales nucleares durante un apagón general?

Hoy 28 de abril de 2025, tras el apagón que se ha producido en la red eléctrica, muchos me habéis preguntado cómo afectan estos sucesos a las centrales nucleares. Quiero trasladaros un mensaje de tranquilidad: las centrales están perfectamente preparadas para este tipo de situaciones.

De hecho, el cero de la red eléctrica es uno de los escenarios que más se entrenan y para el que mejor están diseñadas las centrales nucleares. ¿Qué ocurre exactamente? Ante la caída de la red, el sistema de protección actúa automáticamente: el generador eléctrico se desconecta de la red por ausencia de demanda para protegerse. Al mismo tiempo, en décimas de segundo, se envía automáticamente una orden de parada del reactor.

La reacción de fisión en cadena se detiene en menos de 1,5 segundos en un reactor de agua en ebullición (como Cofrentes) y en menos de 3 segundos en un reactor de agua a presión (el resto de reactores españoles). A partir de ese momento, el reactor ya no produce suficiente calor para generar electricidad, pero todavía tiene lo que llamamos calor residual, debido a que los productos de las fisiones son radiactivos y emiten energía y partículas dentro del reactor que se convierten en calor. Ese calor es necesario extraerlo y va decayendo con las horas y los días.

Normalmente, parte de la electricidad que genera la central se dedica a su propio funcionamiento: bombas, sistemas de refrigeración, válvulas y controles. Pero cuando la red falla, las centrales cuentan con generadores diésel de emergencia capaces de mantener todos los sistemas esenciales y de seguridad en funcionamiento. Estos generadores arrancan automáticamente y en menos de 13 segundos ya son capaces de funcionar de forma continua durante al menos 7 días seguidos. Además, cada central dispone de, como mínimo, dos generadores diésel redundantes (cada uno con capacidad suficiente por sí solo) y, desde Fukushima, también cuentan con generadores portátiles adicionales.

Como medida de seguridad adicional, las centrales nucleares suelen estar directamente conectadas a centrales hidroeléctricas, de forma que podrían recibir suministro alternativo incluso si la red general fallara y los generadores diésel también.

Como se puede ver, los apagones generales están previstos en el diseño de las centrales nucleares y son uno de los escenarios que más se entrenan, tanto en los simulacros como en las sesiones de simulador de los operadores.

[Noah Jakob Rettberg 🇩🇪🇪🇺 @NoahRettberg]

"What the Hell is Going On in Spain?"

At around half past eleven today, Spain and Portugal experienced an almost nationwide blackout.
Small parts of southern France were also briefly affected but reportedly regained power quite quickly.

The Portuguese grid operator currently attributes the likely cause to weather-related oscillations in power lines, which caused the grid to collapse.

At the time of the load shedding, Spain’s electricity supply was in a very fragile state: 70% of the electricity was generated by producers without grid-synchronous inertia.

Grid-synchronous inertia refers to turbines in nuclear, coal, gas, or hydroelectric power plants that drive the generators of these plants.
The rotational speed of these turbines is synchronized with the frequency of the power grid.

Thus, the grid frequency is directly linked to the rotational energy of the turbines.
If the frequency drops, it means that the load on the grid exceeds the output of the power plants connected to it.
In such a case, the rotational energy of the turbines is converted into electricity to stabilize the grid.
The valves on the turbines respond by opening further to support the grid.
The opposite situation can also occur: if there is excess generation, that energy is absorbed as rotational energy, and the turbine valves close accordingly to adjust to the new load.
Although the rotational energy compared to the grid’s power consumption is not large, it is sufficient to stabilize excessive load fluctuations or absorb surplus generation until the valves have time to react.

This principle of grid-synchronous rotating masses has been the foundation of our power grids for over 100 years, ensuring that at every moment exactly as much electricity is produced as is consumed.

Over the past two decades, Europe has been rapidly building power generation facilities that do not use grid-synchronous turbines, but instead produce direct current, which is converted to alternating current via inverters:
Wind and solar energy.

These inverters can generate high-quality alternating current, but they cannot replace the function of grid-synchronous inertia.

The more wind and solar power is integrated into the grid, the fewer conventional power plants with grid-synchronous turbines remain.
The fewer grid-synchronous turbines there are, the less inertia there is to buffer instantaneous fluctuations in load.

If there is insufficient buffering, even small fluctuations can quickly cause the grid frequency to deviate dangerously from the ideal value of 50 Hz.

Consumers and producers alike respond to this by disconnecting from the grid for self-protection, which can trigger a cascading collapse.

What exactly tipped the balance in Spain remains unclear.
However, we do know that the Spanish grid was in a highly volatile state at the time of the collapse.

Please note:
This text is an AI translation of my orginal German language Tweet.

[Jacobo de las Alas-Pumariño @jacobo_dlasAP]

@MyInvestorES Por algún motivo mi cuenta no me deja comprar fondos, cuando meto la firma electronica sale un mensaje en rojo " Instrumento no está disponible Comprar".
¿Que puede ser? Los fondos de Gamma global y Sigma Internacional

[Bill Ackman @BillAckman]

Letter from a tank commander in Gaza to the Israeli people. I cannot confirm its authenticity, but it appears to be real:

Hamas is stronger than the left. It is also stronger than the right, and also Bibi & Ben Gvir. Our enemy is stronger than Israeli high-tech and the settlement enterprise. Tel Aviv's beautiful soul has no chance against them, nor does the periphery.

But Hamas has no chance against Israel. When we are united and mobilized, they retreat into their tunnels and pray for a ceasefire.

This war has stuck me in a tank, sharing it with two comrades, between two "Shiny Sheens" one who served a year and one who served four, a Smotrich voter, and a Ben Gvir voter, and I seemingly have nothing in common with them. But the army's melting pot poured us back into one unit, a tank crew. At some point, we adopted and started talking about everything. About the Haredim, about the Supreme Court, public transportation, core studies, even sexuality, everything.

And what did we discover? That we agree on about 90% of the issues. Let's assume they are really nice and were being agreeable, so about 80%.

Until about a month and a half ago, they were the enemy. We met on both sides of the fence, but Hamas reminded us that we are essentially on the same side.

Our politicians draw their strength from the division between us. They take the 10% - 20% disagreement between us and turn it into the main thing, because that's what gives them a mandate to "represent" us, to fight in our name. They do it at the expense of our security, our welfare, our taxes, and our freedom (also our freedom to pray, by the way).

I see many people looking for ways to contribute to the war effort, Sending underwear, socks, cigarettes, and combat gear. Moroccan mothers who sent us fish and couscous for Shabbat, and kibbutz retirees who drove these pots to across the country. Techies who came to install 360-degree cameras on the tank, something the army is not quick and flexible enough to do on its own. And hilltop youth that the army refused to draft at all, came on Saturday, cut, sowed, and stitched so that we wouldn't enter Gaza without protective covers shielding us from drones.

As far as I'm concerned, the most important contribution is for you to unite as a people, work to come closer. Focus on the similarities and set aside a bit of difference. Invent frameworks that will connect us even outside the army. I know it's complicated with issues of kosher and modesty and separation and no-separation, but I trust you.

This is the most important thing, that we be together. Because we, the soldiers, from all our tribes, enter enemy territory and endanger our lives not for any government or politician, but for the people of Israel.

Please, make sure we have a country to return to.

[Bill Ackman @BillAckman]

.@elonmusk is not an antisemite. I agree with @benshapiro’s assessment of the situation.

It is remarkable how quickly the world stands ready to attack Musk for his shoot from the hip commentary.

Musk is not perfect, but the world is a vastly better place because of him.