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.
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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
sites.
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.
Q10:
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.
Q11:
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.
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