Eskom’s renewed interest in the PBMR

South Africa's first nuclear energy plant, Koeberg.

South Africa's first nuclear energy plant, Koeberg.

Published Mar 29, 2017


EE Publishers’ investigative editor, Chris

Yelland, and assistant editor, Pierre Potgieter, interview Eskom’s chief

nuclear officer, David Nicholls, on the utility’s renewed interest in the

Pebble Bed Modular Reactor (PBMR). Nicholls explains the potential of the project,

which is currently still in its research phase. Below is their conversation,

edited for clarity.

Q1: What

is Eskom’s new vision for the previously abandoned Pebble Bed Modular Reactor (PBMR)

project, and how did this new vision come about?

The new vision is very similar to the old

vision. It’s looking whether there’s a market and potential for ultra-safe,

small, nuclear reactors for power generation, using high-temperature technology.

When Brian Molefe came into Eskom he reviewed what Eskom had stopped doing over

the last few years, and asked why we had closed the PBMR project down. In his view,

it was neither for technical nor commercial reasons, but a mixture of many other

things. We were asked to look at the project again to see if there was a better

solution. We’ve started again with a clean sheet – a paper study with limited

research funding going into it. It’s more emotion than money at the moment. We’re

looking at a much simpler and much more efficient plant than we had the last

time round.

Q2: Since

the first PBMR project in South Africa was abandoned in 2010, is there still a

window of opportunity for the development and commercialisation of small

modular nuclear reactors by Eskom for South Africa and the global market?

I think there’s a window of opportunity still

there. In some way initiated by the former PBMR project in South Africa, many

studies have looked into small nuclear reactors, and they conclude that power

generation reactors of 150 MW or so could be commercially viable – which no one

had thought previously possible. But no one has yet filled that window. We

certainly haven’t seen a competitor in the marketplace that has filled the hole

that PBMR was trying to fill. And there is much interest once you get to the

stage of building the first couple of machines – certainly in the African market,

and certainly for the small grid. It would also fit in terms of load-following for

a grid with a large amount of renewable, intermittent generation.

Q3: Would

these small modular nuclear reactors for power generation be a factory-built kind

of product, or site-built, or a combination of the two?

There are always site activities, but

basically the smaller and more compact the machine gets, the more factory manufacturing

becomes possible. Our view would be that you could apply factory manufacturing

to most of the components we’re looking at. One cannot do concrete and civil

construction things in the factory, but I think the idea of a mass-produced factory-built

machine is exactly where the PBMR is moving. You atomise the engineering cost,

you atomise the design costs, and you atomise the skill-set of the people

building it.


Q4: Would

the new PRBR simply be a resuscitation and continuation of the previous PBMR project,

or would there be any significant technical or other differences / improvements?

This new project is not simply a

resuscitation of the PBMR project, it’s based upon the PBMR technology and what

we learned doing that. At the moment it’s sort of lab-scale research work with minor

engineering, and it will stay that way for some time to come. But yes, it looks

at taking advantage of what’s happened in the last 30 years. The PBMR was

fundamentally designed in South Africa in the 1990s, based on German technology

that was demonstrated in the 1970s and 80s. The new work we’re doing now has

been looking at what has changed since then, and how we can change the PBMR

design to take advantage of this. Probably the best example is 3D printing. We

can now consider 3D printing the ceramic materials, which would have been

unthinkable 20 years ago. We are also considering the use of concrete pressure

vessels instead of steel, which could reduce the price significantly. 

Read also:  Strong response on Nuclear - Eskom

The fuel would essentially be the same as

was produced for the previous PBMR project in South Africa. But based on tests

conducted in the USA, we know that for our fuel, the upper design limit of

1600°C for the German fuel can now be increased beyond 1800°C, and possibly as

high as 2000°C, which pushes the reactor envelope significantly further.

Q5: Do

you envisage that the further development, piloting, commercialisation,

licencing and construction of the new PBMR would be done directly by Eskom, as

opposed to funding by the South African government, external shareholders and

additional Eskom debt?

You’re asking me the question probably a

year or two too early. We’re still looking at the research, and conceptualising

a proof-of-concept machine. We’ll first have to come through this research

phase, assuming we get results we that we like, before we come up with a

proposal on what the costs would be, and how to go forward on these costs.

That’s a choice we’ll make at that time. At the moment it’s being funded from

Eskom’s pre-allocated research budget.

Q6: In

the new vision, does Eskom have a clear idea of the cost of developing,

commercialising and construction of the new PBMR?

At this stage we’re doing research. What

will come out of this in future is a view of the cost to develop the design,

the cost of a proof-of-concept machine, and the potential cost of a commercial

machine. We will then have to look at the business case that goes with this. We’ve

got very limited funds at present, and we’re doing investigations before going

back to our principal and shareholder, the government, to ask them for approval

for any outcomes proposed. So at the moment we’re trying to conduct a proper

research process of what is possible, not based upon what was or what could be

done in the past, but what can be done now and in the future.

Q7: This

time round, what would be the envisaged time-scale for deployment of PBMRs in

South Africa, where would you deploy them, and for what purpose?

The last PBMR was meant to take a

pre-existing German commercial package, rearrange it, and put it in the

marketplace. That was to be quite a quick process. This time, we are looking

more at a research project. We are looking at having a proof-of-concept machine,

i.e. a research machine, running by the mid-2020s, if all goes well. And then potentially

starting a commercial machine roll-out starting ten years after that.

From about 2027 onwards, the need for base-load

capacity becomes quite urgent if we assume we are going to have any kind of economic

growth, and that we will have to decommission several of Eskom’s coal stations.

In our view, this need for base-load capacity will probably be met by building

large pressurised water reactors (PWRs). Then some ten years after that, when

the famous 9.6 MW nuclear new-build has been done, we could possibly be looking

at doing PBMRs.

Read also:  Pebble bed project's closure generates explosive debate

As to why and where to deploy them – look,

Eskom is a power generation business. That’s why we’re gearing up the concept.

To this end, the PBMR will be seen as potentially replacing some of the current

coal fleet. If you look at the 2030s – you look at possibly replacing old coal

stations with high-temperature PBMR reactors deployed on the old coal-station


Q8: To

ensure some level of certainty, would Eskom commit upfront to purchase say the

first ten such PBMRs, as Eskom initially did previously before it subsequently

withdrew such commitment?

It’s way, way too early to ask that

question. I haven’t got a clue. Ask my successor, or my successor’s successor,

that question. I’ll be retired by then!

Q9: To

meet this vision, does Eskom have the necessary deep pockets and nuclear design

capability, and does SA have the necessary depth of nuclear engineering

capacity and experience?

I think, to answer that question very

simply – in terms of deep pockets: no comment. We’ve discussed money already,

and we haven’t got a clue yet. But I think you’ll be surprised how much depth

Eskom and the country has in terms of engineering. In this particular

technology, namely high-temperature nuclear reactors, we were the world leaders

by a good margin. And most people are still around. It’s interesting how many

of them now work on other projects in the USA and elsewhere, based on their

work in South Africa. And I think the answer to the question is that we didn’t

have a problem with resources on the previous PBMR project. Personally, I don’t

believe that if this goes into a serious engineering phase we’ll have a

particular shortfall. My experience is that you create engineers by doing

things, not by doing studies.


Is it really Eskom’s role as a public electricity utility to involve itself in

the design, engineering, piloting, commercialisation and construction of PBMRs

in SA and globally as a nuclear technology developer and EPC contractor?

All business is in the business of taking

risks. To the first question of should we be in the business of an EPC

contractor, the answer is: we did it in the past, and in my view, it’s a

central theme in a company like Eskom. We continue to build transmission lines,

we continue to be an integrator of these technologies. Should we be in the

design-engineer-commercialisation experts? – I don’t know, and I don’t know how

this will play out. We’re looking at technology options, and we’re looking at

some of the techniques to manufacture them. How it will be rolled out if it

works, I don’t know. It could be through a PMBR company created for this

specific purpose. In fact, there are successful utilities around the world, a

lot of them with own engineering, procurement and construction activities.

Eskom used to do this big-time, and successfully, in the 1980s.


What did Eskom learn from its previous diversification forays through Eskom

Enterprises and PBMR?

I’m not sure what Eskom learned, but I’ll

give a couple of answers from my perspective.

Firstly, start slowly; don’t leap into

something with both feet, thinking you understand the whole marketplace; work

up to it; make your decision wisely; but once you’ve made the decision, don’t

stop halfway through. If you put this in the context of the PBMR, you’ve got to

think where this takes you.

Secondly, get management engagement. That’s

what is so exciting about this project from the beginning. [Former Eskom CEO

Brian] Molefe did his homework, he did his research, and he said: “Given this

research, please can you do this for us”.

In this case we said very clearly that we’re

not just going to leap into another PBMR project; we’re looking at the

technologies; we’re having a technology discussion. Technology leads to

engineering, which leads to money. Not money as in spending money, but money as

in: “If I’m going to build a concrete pressure vessel, how big will it be and

at what cost?”

Are we going to build PBMRs? I have no

idea. But I do know that we will end up with a bill of materials for the

theoretical plant to indicate whether we can afford it or not.



Related Topics: