A visit, with my son and a couple of friends, to Torness nuclear reactor – which anyone, by the way, can book. Yes, this is the kind of thing me and my pals like to do, of a bank holiday weekend: tour a power station or industrial site.

I hadn’t gone there intending to write about it – not immediately anyway - but then in the days that followed there were stories.

There was, for instance, GMB boss, Garry Cook, accusing the Scottish Government of being “rooted in the past” in its opposition to nuclear ,  UK energy minister, Andrew Bowie describing the SNP and Greens of having a “luddite mentality” - and the announcement that Bill Gates’ TerraPower was poised to throw its hat into the ring in the competition to develop small modular reactors in the UK.

READ MORE: 'Rooted in the past': Unions blast SNP over nuclear power snub

More sobering, there was also, in Ukraine, the evacuation by Russian forces of residents from a town near the occupied Zaporizhzhia nuclear power plant as extreme concern was voiced over the safety of the facility.

All these were reminders that, in this age of both renewables revolution and energy-price crisis, the debate about nuclear is not going away.

The stark, grey block, as we approached it, seemed to stare back from a darkening sky. Torness, slated to be decommissioned in five years' time, following the identification of cracks in its core, ipowers the last of the UK's advanced gas-cooled reactors, cooled by carbon dioxide and moderated by graphite. When it closes, and begins its decommissioning, there will be, the guide told us, no nuclear power stations in Scotland.

Its capacity to fuel over more than two million of our homes will then come to a full stop.

Some of what we learned from the tour guide was startling. A person is exposed to more gamma rays whilst flying than they are whilst standing on one of the station’s reactors. Brazil nuts are a highly radioactive food. The carbon dioxide which is used to cool Torness is brought in from the Netherlands and is a product of the brewery industry.

READ MORE: Government to reopen competition for small modular reactors

But what lingered most in my mind was staring down into the circle of the nuclear reactor. It was the aesthetics of the control room, which bore the design of another age. Looking down into it felt like traveling back in time: lowing buttons and ivory panels, green and red 1980s-style phones, and box files lining the walls.

It’s hard not to look down into the control room of a nuclear power station and not think of Chernobyl, even when this is Torness, a very different reactor model. Reports may tell us – and they do – that nuclear is incredibly safe, but the thought is hard to dismiss. The main message of the tour seems to be to dispel that.

But the key question for me isn’t simply safety, but the weighing up of the whole equation of safety, waste, security and cost. It's the question of what we need to create the cheapest, safest, most secure formula in terms of energy mix.

And one thing we can see from Torness is that nuclear doesn’t always, like many projects, deliver its promise. Here we have a project which, in 1989, was acknowledged by the Scottish Office to be, in terms of costs, a mistake. That's worth remembering when people tell us that small modular reactors will be quicker and cheaper to construct. 

In an era of renewables expansion, is the necessity of nuclear really that outstandingly obvious that we should call those that dismiss it luddites?

Ultimately, of course, that question comes down to whether we need nuclear to provide what is called baseload.

READ MORE: Nuclear energy chiefs under fire over cheaper than renewables claims

Before my tour of Torness, I’d come to think that the problem with new nuclear, and its potential to plug the gap left by the East Lothian power station, was expense and how long it took to construct.

Since visiting, and also watching the March session of the Scottish Government  Net Zero, Energy and Transport Committee, I’ve come to feel the problem is not just that the nuclear plug is expensive, slow and problematic – but that almost all answers to the baseload/storage question are.

There are clearly various ways of providing storage that would replace nuclear’s baseload – options that include hydrogen, pump storage hydro, and batteries - but they all share a common problem with nuclear, and that’s the speed of their development.

We are well-placed in Scotland to develop the giant reservoir-sized batteries of pump storage hydro, but even the financial mechanism for this looks unlikely to be till 2030. Green hydrogen had huge potential, but again, we are slow off the marks on this.  

Torness, in its final years, gives us an insight into our past energy. A tour around it feels like a plea for replacement - a gap that needs to be filled. It's a reminder not just that we don’t have to build new nuclear to replace it, but that we don’t have a clear map for our alternative energy future - and in the absence of that, the question about whether we need new nuclear is never going to go away.