Nuclear - future for Ireland?

https://pris.iaea.org/PRIS/CountryStatistics/ReactorDetails.aspx?current=607

The Annual time on line and Annual Load Factor in the original link I posted clearly show that it's not demand following. Check the hours vs. % and it looks to be on full load during the year that it's not refuelling. Mostly.

It appears to be refuelling every second year , so would need backup during that time. The dips in those years look to be more than just the refuelling times though.

Like I said the other reactor at that site went offline and took out another power plant too. Spinning reserve is essential. I don't know how we'd provide enough spinning reserve on our grid to handle that much failure and keep emissions low.

You need to provide low/zero carbon replacement power while it's refuelling. Typically for a month but inspections and maintenance take longer. Outages get extended too.

What's your plan for when an automatic shutdown takes out one plant and then starts to cascade ?

You can't ramp up nuclear. As for refuelling at low demand ? Only half the generators in the UK are at nominal full load in a country that imports 20% of it's electricity,

Haysham 1, Reactor 1 is now at 397MW raising load , Reactor 2 will be down till December

Hartlepool , Reactor 1 is at 134MW , raising load , Reactor 2 is till on unplanned outage , turbine rotor work

Heysham 2 Reactor 7 is at 291 MW - At reduced load due to boiler feed flow restrictions

For renewables the simple argument is that the amount of storage and backup and peaking needed to support nuclear outages would cater for forecast drops in wind and solar. And renewables are providing power now , not in 20 years time.

Gross electricity imports and exports as a share of British electricity demand each quarter.

https://reports.electricinsights.co.uk/?p=2226

You will notice how France had to import a lot of electricity in 2022 when nuclear had systemic failure. But 2010, 2016, 2017, 2021 also saw large imports by France especially in Q4. Nuclear simply isn't as reliable as often claimed.

Nuclear here is at least 20 years away because of the lead times on Public Relations, legal challenges, tendering process, pre-construction works, actual construction of the roads, pylons, site works, reactor / nuclear island, turbines , commissioning and ramping up to full commercial operation.

Our emissions plan is to reduce to 5% by then and decrease by 1% a year, So the best nuclear could do is only reduce emissions by 5+4+3+2+1 = 15% of one year compared to what we have to do anyway. And nuclear like renewables is dependent on grid upgrades (eg: pylons) , peaking plant and storage.

However, nuclear requires way more spinning reserve. Unless and until we have 1.6GW of batteries fully charged and ready to to go we would need gas turbines running at partial load (inefficient so lots more CO2) except we can't because of the emissions. Or we could have 7 Turlough Hill's spinning in air which would require about 2% of that power being wasted, and the construction and planning permission for 6 more of them, But that would mean nearly 10GWh of dispatchable storage which within the emissions limits would allow us to keep going for yonks.

Primary Operating Reserve needs to be 75% of the largest generator on the grid. And runs for 5 - 15 seconds. Batteries or demand shedding (including stopping the pumped storage pumps) or gas turbines running at reduced power can respond this fast.

You can't use batteries or pumped storage if they're empty.

Batteries are Non-Synchronous Generation which needs to be kept below 75% at present so even if you had enough batteries you may have to curtail nuclear's output such that if it fell off the network you'd still have 25% met from synchronous generators.

For Secondary Operating Reserve (15 - 90 seconds) in addition to the above you can also use pumped storage but only if you already have the turbines using electricity to spin them in air so they are already up to speed. And that's no use if there's a unplanned outage because it takes longer than 15 seconds for the water to fall down to the turbines AND then bring them up to speed.

https://www.sem-o.com/publications/general-publications has Week 45 Operational Constraints because you still need local voltage stability too. And nuclear plants generally aren't near cities.

The lovely thing about SMR's is that there is no danger of them actually going into production any time soon.

So the multinationals can kick the climate change can down the road by announcing major future investments instead of investing in other technologies that would deliver real results now.

In theory SMR's would be a good match for data centres with their constant loads. In the real world every half decent data centre already has backup like flywheels or batteries until they can get their generators on line, So they could export power, or by using their own generators they could shed demand. They are already flexible. Exporting excess heat for use as district heat is already happening so there's that reduction in fossil fuel by others.

It doesn't matter how safe they are if they can't be delivered in time. There is no point in even considering them until they are in production and fully debugged.

We'd need to keep the lights on in the meantime and you'd need to suggest how to do that in a way that doesn't remove the need for nuclear. It doesn't matter if nuclear can do this if we've already solved the problem.

Nuclear projects are high risk and low reward.

According to their own timelines Rolls Royce would have working ones by now, had they had invested their own money. Unlike most of the rest of the snakeoil salesmen RR have been making SMR's since the 1950's. They have a pile of assets and guaranteed income from thousands of airliners on order and the maintenance contracts through the life of those airliners. If they aren't willing to invest their money , we shouldn't either.

There's still no commercial SMR's. Even though hundreds have been made in series production since the 1950's.

Lots of companies looking for venture capital but nothing actually built. China and Russia have small reactors but they aren't ready for mainstream grid use even if they were selling and even if we were buying.

https://ww2.nrc.gov/reactors/operating/ops-experience/scrams

I hadn't realised that nuclear was that unreliable. A SCRAM a week in the USA.

It reinforces the point that nuclear need spinning reserve. Since nuclear generators are multiples of the size of the next largest generators the capital and running costs of additional spinning reserve must be met by nuclear alone or it's a backdoor subsidy.

The problem for nuclear is how to provide that reserve without increasing carbon emissions. And that reserve makes renewables look more attractive.

I doubt there'd be enough money held in escrow for the decommissioning and cleanup.

If the data centres then needed power they would enter the bidding war with everyone else which would push up prices.

The €10 Bn for Sizewell was based on your own link, and the current price is €38 Bn. not €50Bn

Which link? And you then need to explain how you didn't twig it was unbelievable low compared to the costs regularly being posted here for it and similar plants. The nuclear industry has a long history of bait and switch when it comes to pricing.

The current amount earmarked for it is €52Bn and the extra money is as good as spent because the contractors won't leave it on the table unless they've had a conversion on the road to Damascus.

I will take that accusation as an admission. You are quoting €38Bn when you know it's £38Bn (€43.4Bn)

Regardless it still has to be paid. If you can sell full load output for 8,000 hours (uptime of >90% in a good year) then the hourly rate will be lower than if you only need it when wind dips during the darker months. In which case you'd only have 4,000 hours and only be able to sell half your output. And suddenly nuclear electricity costs four times as much because those billions still have to be paid even though you are only selling a quarter of the energy.

Conmen being confident ? Will wonders ever cease. It's bait and switch 101, and the key decisions makers will be safely retired before the fertiliser impacts the spinning thing so there's no back pressure there against corruption.

Since nuclear isn't going to produce any power for the next 20 years we have to keep investing in renewables and storage and grid upgrades. So the cost savings during this time are exactly zero.

It's not a choice of nuclear or renewables you have to pay for both and given the history of delays in nuclear you can't stop investing in renewables until nuclear is up and running. Even then Chinese EPR had fuel rod issues soon after startup and had to go offline for a year. With OLK3 it was pumps that took it offline for months. Flammanville will need an extended outage too.

For nuclear you need a grid that can replace 75% of a reactor output within 5 seconds. That can also provide replacement power for the month or two every 18 - 24 months when reactors are refuelling or doing maintenance. Yes , predictable nuclear outages last longer than dunkelflauten. Unpredictable outages can last even longer and can and do happen when you already have another reactor offline.

A grid that could handle nuclear would be easily able to handle the changes in output of wind farms which are forecast days ahead. In twenty years time the likelihood is that we should be able to forecast another 2 days further ahead.

Enough storage to keep the lights on most nights during the months with longer days will look more attractive as the costs of solar and batteries continues to fall.