SUBMISSION ON
NUCLEAR-ENERGY IN SOUTH AFRICA
15 June 2007
SOME THOUGHTS
(in response to an invitation to
the public issued by the Portfolio Committee on Environmental Affairs and
Tourism) By J. F. Siebert Pro Eng:Consulting Engineer (ex S. A. Atomic Energy
Board, EsKom, and the National Nuclear Corp U.K.)
For the sake of brevity only a summary
of the writer's views (the results of 1 5 years of association with the nuclear
power industry) follows. Paragraph headings (except the first and last) are
those contained in the invitation for submissions.
BACKGROUND
0.1 Prior to any discussion of the energy mix in
0.2.1 Given that an irreducible minimum of electrical generating capacity is
necessary in the country the question remains as to what mix of generating
modes (nuclear, coal, gas, solar, hydro etc) should be employed to achieve a
minimum cost per
unit with due cognizance being taken of reliability considerations and other
objectives and constraints as indicated above. A full multi-objective
optimisation analysis is needed to provide an answer; in the meantime it
remains essential to ensure the inclusion of all germane considerations in such
a definitive study.
0.3 Even the above formulation of the problem is inadequate if one takes into
account the fact that electricity is hardly the only form of exploitable
energy; use of the former to provide heat is in fact thermodynamically
inefficient and the direct use of nuclear energy in devices such as
desalination plants, or urban district heating schemes must also be considered.
0.4 Africa is the least developed of the 5 continents and the opportunity (or
duty!) exists for S Africa to guide it into a pattern of energy consumption
appropriate to the novel lifestyles that (particularly) African populations
will need to adopt in a century that will see critical shortages of fuels,
water and other resources. Africa's greatest energy assets are its potential for
hydro-electric generation and solar power (both renewable) and it would be
unconscionable were these not fully exploited before turning to more
problematic technologies (see Paras 2 and 3) especially in view of the limited
capital available for energy investment.
0.5 Most fundamental to long-term energy-planning is an examination of the
desirability (let alone possibility) of never-ending economic development and
the holding out by politicians to voters of democratically constituted
countries the prospect of U.S-style consumption patterns. Curtailment of these
expectations and acceptance of more modest material circumstances (which do not
imply less fulfilled lives) would radically influence energy forecasts.
1 SOCIO-ECONOMIC IMPLICATIONS OF NUCLEAR POWER
1.1 The socio-economic implications of nuclear-generated electrical power (to
be specific) would clearly be conditioned by the extent of the 'roll-out' of
any program and whether or not it was additional to, or a substitute for an
alternative-program of coal-fired generating capacity possibly incorporating
clean coal technology or C02 sequestration. Arguably employment opportunities
would be unaffected, as (for example) a reduction in coal-mining activities
supporting the latter would be offset by an expansion in uranium mining and
processing. Indeed as an exporter of 'yellowcake' the possibility of S
Africa's 'adding value' to raw U308 by establishing significant facilities for
its conversion to gaseous form (UF6) , and even enrichment (see later) are not
beyond the bounds of possibility. (Such a scenario was examined in the 1970's
with the manufacture of fuel assemblies under license the final goal)
1.2 Historically the capital cost of a nuclear power station has been 30-40%
higher than that of a coal-fired equivalent although how this relationship may
change with the fitting of C02-reducing measures is unclear. Whether these will
become mandatory under some successor to the Kyoto Treaty on greenhouse gases
is open to question; certainly
1.3 In most countries where nuclear power is a real possibility, resistance to
it appears to be diminishing, no doubt in the face of the perceived greater
threat of global warming and the fact that no major nuclear incidents have
occurred over the last 20 or so years. As the number of nuclear power plants
world-wide increases and those now in operation age the chance of another major
accident becomes statistically likely; with unpredictable effects on public
opinion.
2. WASTE MANAGEMENT
2.1 Waste management remains the chief obstacle to the
general acceptability of nuclear power by virtue of the malign properties of
long-lived fission products produced in nuclear reactors. Consequent dangers
are two-fold: (1) accidental discharge through natural
processes-(eg"eaTthquake, diffusion processes) into potable water
suppli~S"or the food chain; (2) dispersion ofthe waste into the
environment by terrorist activity using various methods.
2.2 While in principle the waste management problem may be solvable through
rigorous administrative controls supervised by bodies such as the IAEA , their effective implementation would be highly
vulnerable to the well-known tendency of the taxpaying public to be
unsympathetic to long-term government spending on projects with little tangible
benefit. This phenomenon is already evident in
2.3 Waste management difficulties are magnified enormously if mixed oxide fuel
is used in reactors. The manufacture of the fuel containing a mixture of
plutonium and uranium oxides involves the 'reprocessing" of spent uranium
fuel assemblies and is a notoriously 'dirty' operation giving rise to copious
quantities of high-level waste. Yet in the light of a potential shortage of
natural uranium it is often seen as desirable by energy economists, and even a
partial solution of the waste management problem.
2.4 The decommissioning of obsolete nuclear power stations which may be seen as
another aspect of waste management represents a further often neglected and
unknown nuclear power cost.
3 SECURITY OF SUPPLY
3.1 Natural uranium (U308) is widely available (
the total uranium content; since most power reactors operate using a U235 concentration
of about 2% or more, 'enrichment' of natural uranium to that level is required.
This process (in any of its various forms) is energy intensive, and politically
contentious in view of its place in the chain leading to the manufacture of
nuclear weaponry. Security of supply of uranium fuel for possible S. African
nuclear power stations therefore hinges on the further development of the
Nuclear Non-Proliferation Treaty and whatever international regime may be
constructed to deal with the enrichment requirements of individual countries.
Prospects are not hopeful in a world in which disruption of energy supplies is
now a standard diplomatic ploy.
4. HUMAN RESOURCE DEVELOPMENT
4.1 While nuclear power exemplifies high technology, this is mainly in the design
and fabrication of critical components (pressure vessels, reactor internals
etc) Such activities (in the case of large 'Koeberg-type stations) would more
likely than not be performed outside of S Africa by non~South African
engineers. Even in the case of the Pebble-bed Reactor (PMBR) only a small cadre
of South Africans need be directly involved in view of the international nature
of the project (but see Para 5) and the global nature of any engineering
contractor competent enough to undertake sophisticated metallurgical and
forming processes. On the other hand it is possible that in view of its
foundational role in PMBR technology South Africa could in the event of the
technology being widely adopted become the specialist supplier of certain
components (as has already happened to some extent in the aerospace and
automotive sectors)
4.2 At the moment there are (to the writer's knowledge) no South African
tertiary institutions offering courses on nuclear power. This is an omission
that under any circumstances should be rectified on an appropriate scale. As
things are a worldwide shortage of engineering skills is proving to be a
constraint in the expansion of all forms of energy infrastructure.
5 SCIENCE AND TECHNOLOGICAL
IMPLICATIONS
There is no doubt that the announcement of a program of nuclear expansion
including some PBMR-driven generating capacity would be a major stimulant to
scientific research and development in S Africa; less so if the program were
exclusively based on large 'Koeberg-type' PWR reactors of 900 Mwe or so,
purchased 'off the shelf' from overseas vendors. The R+D necessary to develop a
small but efficient 'African' PMBR could mesh well with S African capabilities
(but see 4.2)
6 RECOMMENDATIONS
Nuclear power should not be adopted on a massive scale until the full potential
of hydro-and solar-generation in the subcontinent (taking into account climate
change) has been explored, and utilized. Tax concessions etc should be
immediately introduced to encourage the use of the latter especially for
purposes such as space and water heating. Two 'Koeberg-type' nuclear stations
(900 Mwe per reactor) should be ordered by EsKom , as
well as two PBMR stations of 250Mwe each, financed by international capital.
These would have the effect of both providing power to the national grid as
well as cultivating a core of relevant expertise. Methods of using the waste
heat from such stations should be explored. Demand-side management should be
used (for example the introduction of off-peak domestic tariffs) to limit peak
power offtake,
To cover any shortfall between this figure (plus some minimum reserve capacity)
and total available generating capacity (including the nuclear, hydro and solar
components mentioned above) a number of coal-fired and/or high-efficiency
combined cycle stations
should be also be included in EsKom expansion plans