(Bloomberg) -- France’s energy prices rose amid fresh concerns about corrosion in the country’s nuclear fleet, against a backdrop of widespread strikes that have caused disruptions everywhere from ports to power stations.

French power for next year jumped as much as 7.9%, the most since late January. Day-ahead natural gas prices in the nation advanced for a second day. 

Electricite de France SA must review its program of nuclear-reactor checks after finding a new crack on a pipe at its Penly-1 unit earlier this year, the country’s nuclear authority said. It’s not clear how the review will affect output, which the company expects to recover after multiple outages in 2022.

Separately, strikes over pension reform have interrupted activities throughout the country. They’ve also had knock-on effects in neighboring nations. The situation, combined with a blast of winter weather in northern Europe, is an indication that the region’s energy crisis may linger longer than expected this season.

On Wednesday, roughly 11 gigawatts of capacity were pulled off French the grid because of strikes at nuclear, hydro and fossil fuel plants, according to Sebastien Menesplier, general secretary of the energy branch of the CGT union.

EDF’s French Hydro Power Capacity Cut Again by Striking Workers

France’s four LNG terminals are blocked due to the strikes, the union said separately. Fluxys SA said the strike at its Dunkerque LNG terminal is expected to last until Friday, while Elengy SA — responsible for the others — noted that disruptions may continue until the next union’s general assembly on March 14.

Shipments from refineries operated by TotalEnergies SE and Exxon Mobil Corp. were blocked for a second day, as fuel can’t load due to the labor action. Fuel production at the facilities continues, at least for now.

UK Frozen

Elsewhere, wind power picked up in the UK after a still freeze on Tuesday led the grid to use its back-up coal-fired reserve for the first time. That was partly triggered by the demand from France for imported power due to lower available power capacity there.

Demand for heating is expected to increase in parts of the region this week. Britain is facing snow and ice, a relatively unusual occurrence this late in the season. Scandinavia is set to see unusually low temperates into next week, according to forecaster Maxar Technologies Inc. 

Read: UK Freeze Tests Energy Network as Snow Covers Country 

While European gas stockpiles remain well above the seasonal level, traders are closely monitoring weather developments and LNG flows. Any prolonged disruption to shipments could raise concerns, as inventories can be quickly depleted, making it more difficult to refill during summer. 

For now, competition with North Asia for spot LNG is likely to remain low over the coming months, according to BloombergNEF. That should result in continued high flows of the fuel to Europe, the researcher said in a note Wednesday. 

Dutch front-month futures, Europe’s gas benchmark, settled 2.4% lower at €42.34 a megawatt-hour. The UK equivalent also fell. 

--With assistance from Elena Mazneva and Anna Shiryaevskaya.

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