In short: yes we do...
As another comment already remarked: we do have a big LNG terminal so we should be fine.
And as also remarked elsewhere: the decision to close this power plant was taken long before by the previous (mostly right wing and certainly not Green) government.
The idea was to close even more power plants but these plans have been changed. So there ARE some more of your beloved nuclear power plants working for a bit longer.
But why close them in the first place?
First en foremost: cost. Keeping them running increases the cost of electricity for everyone. Due to a complex interplay of regulations and market forces everyone pays extra for the electricity of nuclear powerplants. Just like the today prices of electricity are heavily influenced by the gas prices even when you buy 100% wind energy. And yes, before anyone remarks it, this has to do with the base load capacity.
Another issue with nuclear power plants also has to do with base load capacity: since nuclear power plants cannot power up and power down at will (the current power down has been planned for months and will take a week to complete) it follows that nuclear power is the first in line to deliver power. This means that if the base load of a nuclear power plants in the network is very high it starts to be economically unviable to deliver wind or other renewable energy to the grid since these power sources would only serve to fill the 'gaps' in power demands. And this despite a lower price for these forms of energy.
This means that as you try to transition to more renewable energy you have to take nuclear power (at least partially) out of the equation.
Next: clean-up. There has been considerable discussion about who has to pay for the costs of the dismantling of the power plant. In the discussion about a possible prolongation it has also been made clear that the costs must be carried by the owner. In that powerplay the government has made it clear that when they were threatening to close some of the power plants they meant business. And recently a law has been passed that establishes the responsibilities of the power plant owner in the clean-up process. Certainly this issue is not fully resolved but at least there is some movement in the right direction.
Lastly: why these reactors? Because serious defects have been detected during a recent (a few years back) safety check.