Safety of nuclear plant in Ukraine at risk amid ongoing fighting

Nick Schifrin:

And to discuss the Zaporizhzhia nuclear power plant, we to turn to Sola Talabi, a nuclear engineer with long experience in the nuclear power industry. He's an adjunct professor at the University of Michigan and the University of Pittsburgh, where he teaches nuclear reactor safety.

Welcome. Thank you very much. Welcome to "NewsHour."

What are the worries about the physical plant in Zaporizhzhia, given the ongoing war around it?

Sola Talabi, Nuclear Engineer:

Right.

So, I think there's certainly a lot of concern here. The — speaking in non-esoteric nuclear terms, you can think of the plant as a system that's under stress. And any system under stress, under sustained stress, would eventually fail.

And the question is really how, when and where. So we can — you can think of three P's. You can think of the people who work at the plant, you can think of the processes, and you can think about the physical structures. They are all under stress.

The people are under duress, working under duress, the threat of violence. So that creates stress. You can think of the processes. The nuclear plant is a very process-driven, heavily procedural. Those processes are under stress.

And, certainly, the physical structure we have seen with the shelling, and that — clearly, that the physical structure is under stress. So, I would say some specific risks include the vulnerability — the vulnerable systems that are outside the containment structure.

So, if you — if you have ever driven past a nuclear plant, you see a big dome. Those components and elements that are inside the dome are generally relatively safe from the physical stress. But there are a lot of critical systems that are outside. And those are certainly more vulnerable to some of the attacks.

Nick Schifrin:

And so one of those systems seems to be the electricity, right?

Sola Talabi:

Yes.

Nick Schifrin:

The electricity needs to remain to the plant. Otherwise, what's the risk?

Sola Talabi:

Right.

So it's something called a loss of off-site power, a loop event, where there are critical cooling systems that require electricity to function. And the key with nuclear safety is really about keeping the plant cool. So any systems that may be affected that are related to cooling that require outside electricity to perform are certainly vulnerable.

Nick Schifrin:

And how concerned are you? I mean, we're talking about the possibility of a radiation leak.

You talked about the safety of the plant itself from sustained bombardment and this electricity risk. How worried should we be?

Sola Talabi:

I think we should be very worried.

And, again, it's because, even though these systems, these nuclear plants are very resilient, and they have redundant systems, they — and they are designed for what's called design basis threats. And these threats are — believe it or not, are still generally within the design basis.

But the fact that they're sustained, that is — that could put them in the realm of being beyond the design basis. And so I would say that, especially, like you mentioned, the electrical systems that support cooling, but also those systems that are outside of the dome, things like the spent fuel pool, which is what — sort of what it sounds like, fuel that's being used, that is stored outside the containment structure, still has a tremendous amount of energy and the ability to reduce — to release radionuclide particles that could create an inhalation risk.

And I think, just in the intro to this segment, someone mentioned that there could be that spread of the way to radionuclide particles throughout the atmosphere. And, certainly, you could have a significant environmental incident.

Nick Schifrin:

The IAEA has said there's no immediate threat, but — quote — "That could change at any minute."

You mentioned the threat of the people, 10,000 Ukrainian staff at this plant, who are operating it under extraordinarily difficult circumstances, literally at gunpoint, reports of torture, some staff disappeared.

How much of a concern is that for you in terms of the plant's safety?

Sola Talabi:

It's a significant concern, because, at the end of the day, no matter how resilient the system is, you need the human factor, you need the human element to execute those processes correctly and effectively.

And so it's — there's a category of analysis called human factor elements. That human factor is currently under significant stress. And if you looked at a plant safety model, you would actually be able, to some extent quantitatively, express the degradation in safety that you have because you have the human factor under stress.

So it's a significant element. The plants are resilient. But any system, again, that's under sustained stress will eventually break.

Nick Schifrin:

Sobering words.

Sola Talabi, thank you very much.

Sola Talabi:

Thank you for having me.