There is zero chance of this incursion making it anywhere close to the nuclear plant. In fact, at this point even pro Ukrainian maps are showing that it's Russia that's on the offensive in Kursk. I also have no idea what morale boost you're talking about as this stunt pulled valuable troops and machinery from the collapsing front in Donbas. Here's what CNN reported just a couple of days ago https://www.cnn.com/2024/09/08/europe/ukraine-military-morale-desertion-intl-cmd/index.html

Two and half years of Russia’s grinding offensive have decimated many Ukrainian units. Reinforcements are few and far between, leaving some soldiers exhausted and demoralized. The situation is particularly dire among infantry units near Pokrovsk and elsewhere on the eastern front line, where Ukraine is struggling to stop Russia’s creeping advances.

As a battalion commander, Dima was in charge of around 800 men who fought in some of the fiercest, bloodiest battles of the war – most recently near Pokrovsk, the strategic eastern town that is now on the brink of falling to Russia.

But with most of his troops now dead or severely injured, Dima decided he’d had enough. He quit and took another job with the military – in an office in Kyiv.

Here's what The Economist reports https://archive.is/KrBmX

Yury, a soldier attached to the 59th brigade based near Ukrainsk, says Ukrainian losses have been significant. A reinforcement of inexperienced infantrymen sent from Ukraine’s 71st brigade were wiped out. “Over three days, 100 became zero. Some ran, some fell.”

The Russians are still focused on control of the roads leading to Pokrovsk. “We have been fighting with our last guard, and have thrown our logistics guys into the trenches.”

“Physicist”, a tank commander with the 68th, says the Russian air force and artillery can react almost in real time; anything that moves and is not protected is destroyed. His tank drivers consequently now mostly work as static artillery units, operating from closed positions, and much farther back.

This has been a gift for Russia because now Ukrainian troops are out in the open where Ukraine is taking much heavier losses than they did while they were dug in. https://www.forbes.com/sites/davidaxe/2024/08/17/out-in-the-open-and-on-the-move-in-russias-kursk-oblast-ukrainian-forces-are-vulnerable-and-losing-lots-of-armored-vehicles/

This also extended the front for Ukraine complicating their logistics situation. The worst part from Ukrainian perspective is that they can't pull troops back because it will be admitting the failure of the gambit. So, now they're stuck feeding men and machines into a battle that has zero long term value while they lose important strategic areas around Pokrovsk.

What's likely to happen in the near future is that Ukraine will lose Pokrovsk which is a key logistics hub through which southern forces are supplied by rail. Once that's lost there's no good way to move supplies or reinforcements south meaning that the group of forces there will be completely cut off. Kursk greatly accelerated this process.