nuclear-news

The ageing nuclear reactors. How to keep them going for decades, (best to forget coming climate extremes)

plant-specific climate simulations do not exist for lower river levels, increased wildfires, or extreme weather events like tornadoes and heavy wind and rain.

Then there’s the issue of what to do with radioactive spent fuel.

Europe’s atomic reactors are getting old. Can they bridge the gap to an emissions-free future?

Reuters, By America Hernandez, Forrest Crellin, Prasanta Kumar Dutta, Anurag Rao and Aditi Bhandari, Aug. 22, 2023

Shaken by the loss of Russian natural gas since the invasion of Ukraine, European countries are questioning whether they can extend the lives of their ageing nuclear reactors to maintain the supply of affordable, carbon-free electricity — but national regulators, companies and governments disagree on how long the atomic plants can be safely kept running………………………………………………

Taken together, the UK and EU have 109 nuclear reactors running, most of which were built in the 1970s and 1980s and were commissioned to last about 30 years.

That means 95 of those reactors — nearly 90% of the fleet — have passed or are nearing the end of their original lifespan, igniting debates over how long they can safely continue to be granted operating extensions.

Extension talk: Bridging the gap or a new lease of life?

Regulations differ across borders, but life extension discussions are usually a once-a-decade affair involving physical inspections, cost/benefit estimates for replacing major worn-out parts, legislative amendments, and approval from the national nuclear safety authority.

In some countries — especially for those that planned to exit atomic power entirely after the 2011 Fukushima nuclear disaster in Japan — discussion is focused on the short term: eking out a few years to get through any shortages before new wind, solar and gas installations can be built to take over.

Anti-nuclear Germany had planned to switch off its last three plants by the end of 2022, only to grant the sites an emergency extension to April 2023 to make it through winter without Russian gas — which previously made up 40% of EU gas supply……………………………………….

So far, Finland, Sweden, Bulgaria, the Czech Republic, Slovenia, the Netherlands and Hungary have all taken steps to allow reactors to run for at least 60 years, subject to regular safety checks.

France, with the largest fleet, is carrying out a major 40-year inspection and refurbishment programme for its 32 oldest reactors.

ASN, the national safety authority, has said France’s pressurised water reactor (PWR) design in principle can be safely operated for 50 years — meaning the ageing plants can run through 2030 — but the regulator will not take a stance on extending to 60 years until the end of 2026……………………………………..

Some companies are pushing the limits further.

In February, Finland’s Fortum obtained permission to operate two reactors until 2050, when they will reach 70 years of age.

In Sweden, where licences are unlimited in time subject to regular safety checks, Vattenfall is considering 80 years of operation for its five reactors……………… More than scientific one-upmanship is at play.

…………………. The cost of pulling the plug

Politicians are also under pressure to keep energy prices low, especially as movements characterising climate action as costly and elitist gain ground.

That means ensuring steady, abundant supply — any swift, unexpected loss of a major source means market spikes and painful household bills.

Energy prices in Europe jumped exponentially in 2022 after many French reactors went offline. The impact was compounded by Russia’s invasion of Ukraine.

…………………………………..The biggest challenge is maintaining the reactor vessel, where uranium atoms are split to release neutrons inside the core. Those flying neutrons also hit the vessel’s steel walls, altering the lattice structure of the metal, making it hard and brittle.

Vattenfall and EDF try to slow down that embrittlement process by layering in special rods of hafnium metal or all……………………………….

Reactor vessels are generally seen as non-replaceable — though it has never been tried.

The same goes for the airtight containment building, which houses the reactor and all associated radiation-emitting parts, to keep it from being released into the atmosphere.

………………………… The French government, which this year nationalised EDF, has estimated it needs to hire and train at least 100,000 workers by 2033 if it hopes to run its fleet long term and build at least six new reactors.

That includes automation engineers, boilermakers, draughtsmen, electricians, maintenance technicians, blacksmiths, pipe fitters and welders.

​​Europe’s new pro-nuclear alliance would require some 450,000 skilled workers if it hopes to build an additional 50 GW of new nuclear by 2050, according to industry lobby Nucleareurope.

2050 and beyond: Hotter, drier, more radioactive trash

Industry cheerleaders point to Dubai’s new Barakah nuclear plant as proof reactors can be successfully designed to withstand desert heat and warmer water temperatures.

But few plants have room to be retrofitted with new safety systems, such as a dyke wall to protect against rising water levels, regulators warn.

“It’s a real headache to find [physical] space on a site that’s currently operating — we have reached certain limits in the feasible modifications of existing reactors,” said Karine Herviou, deputy director-general of France’s Institute for Radioprotection and Nuclear Safety, at the industry event on lifetime extensions.

The French fleet’s temperature margin to withstand heatwaves is constantly questioned, she added, while plant-specific climate simulations do not exist for lower river levels, increased wildfires, or extreme weather events like tornadoes and heavy wind and rain.

As a result, Herviou said in France: “There’s a general agreement that what we’ll do at the 50-year, 60-year mark will essentially be replacements for modernisation but very certainly not adding in any new safety systems … and checking for conformity and respect of already-applicable requirements, without further hiking the safety requirements.”

That rings alarm bells for third-party watchdogs like Mycle Schneider, who compiles the annual World Nuclear Industry Status Report and said ageing reactors need tighter scrutiny.

“You have a car, 30-to-40 years old, and your generator breaks down. You open the hood, the mechanic takes out the generator and then says, ‘Ooh, everything underneath is rotten’ — a 40-year-old nuclear plant is not all that different, you basically find on the go all kinds of things you didn’t expect to find,” Schneider said.

EDF wants the government to relax biodiversity rules which forbid plants from dumping used cooling water into nearby rivers on days they are deemed already too warm, limiting power production — which risks becoming more frequent.

Then there’s the issue of what to do with radioactive spent fuel.

Used uranium pellets, which are solid, are stored in special refrigerated swimming pools designed to cool the radioactive heat down for five-to-10 years. French company Orano then separates out the material into non-recyclable leftovers that are vitrified into glass (4% of the material), plutonium (1%) to create a new nuclear fuel called Mox, on which some 40% of France’s reactors can run; and reprocessed uranium (95%) which for now can only be re-enriched and “recycled” at one plant in Russia.

Non-recyclable waste can be safely stored in dry casks, but its ultimate destination is deep underground, where it will fully degrade over hundreds of thousands of years.

Sweden, Finland and France have plans to build such long-term underground sites………………………………………………………………………………  https://www.reuters.com/graphics/EUROPE-ENERGY/NUCLEARPOWER/gdvzwweqkpw/

August 24, 2023 Posted by Christina Macpherson | climate change, technology | Leave a comment