THE SOCIO-ECONOMIC, WASTE MANAGEMENT AND SECURITY OF
SUPPLY, HUMAN RESOURCE. DEVELOPMENT AS WELL AS SCIENCE. AND TECHNOLOGIAL
IMPLICATIONS OF NUCLEAR ENERGY IN SOUTH AFRICA
Paper submitted by Pebble Bed Modular Reactor (Pty) Ltd to the Portfolio
Committee .on Environmental Affairs and Tourism as input for a Public Hearing
held on 20 June 2007
1. INTRODUCTION
Global energy demand, which is governed by population growth and increase
in standards of living, is presently growing at about 2% per annum. The
electricity component of demand is increasing more rapidly than the overall
energy growth and is projected to increase by some 70% between 2000 and 2020,
almost two-thirds of which will be from developing countries.
Currently, about 2 billion people have no access to electricity. Most
electricity in the world is generated in coal-fired power stations (39%)
followed by hydro (19%), nuclear (16%), gas (15%) and oil (10%). Apart from
hydro-based power generation, renewable sources of electricity such as wind,
solar, tidal, geothermal and biomass are intrinsically or economically not yet
suitable or feasible for large-scale power generation where continuous,
reliable supply is needed. These sources will have most appeal where demand is
for small-scale, intermittent supply of electricity.
The World Nuclear Association lists 435 nuclear power plants in operation
worldwide. About 30 more are under construction, over 60 power reactors with a
total net capacity of nearly 70,000MWe are planned and over 150 more are
proposed. Civil nuclear power has accumulated more than 11 000 reactor years of
operational experience to date.
There is as much electricity generated by nuclear power today as from all
sources worldwide in 1960. Nuclear power is increasingly being regarded as an
important component of the energy mix in countries as part of their strategies
to combat global warming and meet their Kyoto Protocol commitments for
reduction in C02 emissions. The revival of nuclear power expectations is also
reflected in the world uranium price, which increased from $10/lb in 2001 to
the present $135/lb.
South Africa presently has approximately about 39 000 MWe local generating
capacity, 87% of which is coal based and 5% nuclear. The projected future
electricity demand indicates that this capacity will have to double over the
next twenty years to keep up with growing demand. According to the South
African Energy Policy and various statements by government, nuclear power must
be retained as part of the energy mix and the relative contribution should even
be increased.
Mention was further made of the planned establishment of a nuclear power export
industry based on Pebble Bed Modular Reactor (PBMR) technology. Sustainable implementation
of these expectations will require a review of, and coordinated RSA national
strategy for, all the components of the nuclear fuel cycle, particularly in
view of the major changes and downscaling within certain areas of the nuclear
industry over the past 15 years.
The potential contribution of nuclear power to future electricity generation in
South Africa should be viewed against the background of the sustainability of
present plant as well as the anticipated growth in demand.
Assuming that the replacement of the existing 39 000 MWe does not include any
additional nuclear plant, it can be seen that the stated objective of 4 000 MWe
PBMR plant within 20 years (24 PBMR modules) would comprise only 5% of the
anticipated 80000 MWe demand by then. This growth scenario would further allow
all nuclear plants to be located at coastal sites, thus avoiding the high
transmission premiums for delivering Highveld coal power to coastal regions.
This document presents information on the status and expected future
developments in the various components of the fuel cycle in South Africa. It
was generated as an input to the formulation of national strategy and policy
making for the future deployment of additional nuclear power in South Africa.
2.PBMR TECHNOLOGY
The PBMR reactor is a helium-cooled, graphite moderated HTR which uses carbon
and silicon carbide coated particles of enriched uranium enclosed in graphite
to form a pebble or sphere as fuel. Helium is used both as the coolant and
energy transfer medium. PBMR technology was initially developed in Germany,
where two PBMR-type demonstration reactors operated successfully between 1965
and 1989. The PBMR project in South Africa was launched .in 1993 after Eskom
acquired a licence from the German developers of the technology.
2.1. Plant Design
The DPP features a helium-cooled pebble bed reactor with a power output of 400
MWt coupled to a closed cycle gas turbine power conversion unit that consists
of a power turbine driving a compressor on one shaft end, and the generator on
the other as well as a recuperator, a pre-cooler and an intercooler. The main
power system utilizes a recuperative Brayton cycle with helium as the working
fluid. This differs from the German approach, which used a steam cycle. The
rated power output of the DPP is 165 MWe. Reactor inlet and outlet temperatures
are < 500 C and 900 C respectively. The DPP will be a single plant module,
and PBMR power plants will subsequently be marketed as stand-alone or as
multi-module plants, starting with four-module, 660 MWe units. The targeted
levelized unit electricity cost for the four-module plant is < $40/MWt.
2.2. Fuel Management
A PBMR core contains nominally 452 000 fuel spheres, each with a diameter of 60
mm and a uranium content of 9 g. Loading of spheres is done online from the
top, and spheres are extracted through de-fuelling chutes at the bottom. For
initial loading, the core is filled with graphite spheres which are gradually
replaced with LEU containing spheres until an equilibrium core, which operates
with 9.6% enriched uranium containing spheres, is obtained. During operation,
fuel spheres are continually extracted from the bottom and, depending on the
burn-up achieved, either reloaded or transferred to the spent fuel tanks. Fuel
spheres will traverse the core on average six times over some 900 days before
attaining a target discharge burn-up of 92000 MWd/tU. An equilibrium core of a
400 MWt reactor will contain 4.068 t of 9.6% enriched uranium, while the annual
requirement for fresh fuel (on average 489 spheres per day) will be 1.6 t of
enriched uranium, which can be produced from 30 t to 40 t of natural uranium.
2.3. Safety Features
Several critical safety objectives which are normally achieved in existing
commercial power reactors by means of custom engineered active safety systems
are already passively and inherently present in PBMR reactors as result of its
design, materials used and the physics involved. Some of the critical features
include:
·
the high radionuclide capability of the coated fuel
particles even beyond operational temperatures;
·
the large negative temperature coefficient of
reactivity which will ensure prompt shutdown upon loss of coolant;
·
the effective heat removal capability, which will
prevent significant degradation of the fuel and the release of harmful
quantities of radioactivity under loss of coolant conditions;
·
the high heat capacity of the core.
2.4. Nuclear Material Safeguards
The inherent design and operational characteristics of the reactor also provide
certain non-proliferation attributes to the reactor. These include closed
system online fuelling and de-fuelling, the storage of all spent fuel in the
facility, the sensitivity of the reactivity balance to the introduction of
neutron-absorbing material into the core, and the unfavourable isotopic
composition of the formed plutonium for the production of nuclear explosives.
2.5. Project status
Since its establishment in 1999, Pebble Bed Modular Reactor (Pty) Ltd has grown
into the largest nuclear reactor design team in the world. In addition to the
core team of some seven hundred people at the PBMR head-office in Centurion,
more than a thousand people at universities, private companies and research
institutes are involved with the project. Around the world, scientists and
governments are looking to South Africa with great interest to see how the
local nuclear reactor developments unfold.
The PBMR team is currently preparing for the building of a commercial scale
power reactor project at Koeberg and a fuel plant at Pelindaba. The current
schedule is to start construction in 2009 and for the first fuel to be loaded
four years later. Construction of the fist commercial PBMR modules are planned
to start three years after the first fuel has been loaded into the demonstration
reactor.
2.6. Further Development
Further development objectives include the demonstration of PBMR technology for
process heat application in the chemical, petrochemical and mineral industries
as well as for hydrogen production.
While PBMR's research and development efforts were initially focused mainly on
electricity generation, it has become increasingly apparent that the
high-temperature, gas-cooled reactor technology will also enable access to
markets that call for process heat applications. Next-generation high
temperature reactors such as the PBMR can produce hydrogen for transportation
or for upgrading coal and heavy crude oils into usable products, thereby
relieving pressure on natural gas supply (the source of most hydrogen produced
today).
They can also generate process heat for desalination, to extract oil from tar
sands, and for many other industrial applications. Capable through its very
high temperatures of 900 degrees C, the PBMR technology is ideally placed for
these applications. To this end, Sasol is in discussion with PBMR to explore
the possibility of replacing its coal-fired boilers with reactors. Sasol has
also had preliminary discussions with Government about the potential for PBMR
technology and how it can be used in the synfuels industry. It is not
inconceivable that such a nuclear heat supply system could be operating by
2015.
In Canada there is interest from companies involved in the oil sands business
to use the high temperatures created in PBMRs to create extremely super-heated
steam to extract bitumen from oil sands instead of gas-fired plants currently
in use.
PBMR is also a partner in a concept design contract with the US Department of
Energy, to consider the PBMR technology as future source of hydrogen. The project
is still in its pre-conceptual phase, but it could result in the construction
of a South African-designed Pebble Bed Modular Reactor in the US before the end
of the next decade.
The PBMR technology furthermore has desalination properties. To this end, the
Department of Water Affairs has requested PBMR to work on a proposal for
utilising the waste heat of the demonstration reactor at Koeberg for
desalination purposes.
3. SUPPORTING INDUSTRIES
Deployment of new PBMR-based nuclear power capacity will be dependent on
several supporting industries for the supply of materials and components.
Whereas the demonstration plant will contain a fairly high percentage of
imported materials and components, it is envisaged that the local content of
the commercial PBMR reactors will be significantly higher due to the
programme's strategy of promoting the establishment of local suppliers where
thought economically feasible.
Supporting industries for the supply of enriched uranium for fuel production as
well as material and components for reactors such as graphite and graphite
structures, turbo machinery, pressure vessels, heat exchangers and main support
systems (fuel handling, reactivity control, gas conditioning and inventory
control), are of particular relevance. The programme would also require a
nuclear waste disposal service for operational waste and spent fuel.
Local supporting industries for the programme will have many benefits, e.g.
strategic (particularly with respect to nuclear material supply), job creation,
skills development, upliftment of certain industrial sectors, import reduction
and export opportunities. Local supply can, of course only be considered if it
makes commercial sense. It may, in this respect, be prudent to revisit the
reasons for the failure of South Africa's previous ventures into the field of
local uranium enrichment and fuel production.
4. URANIUM-RESOURCESAND-MINING
4.1. Background
Uranium production in South Africa commenced in 1952 as result of the demand
created by international nuclear weapons programmes. Production peaked in 1959
at 5 000 t p.a. U. After a 50% decrease in production, another peak, caused by
the energy crisis of the 1970s, at more than 6 000 t p.a. U, followed in 1979.
Since then, a sharp drop in demand and prices resulted in less than a 1000 t U
currently being produced in South Africa.
More than 95% of the approximately 160 000 t U mined in South Africa thus far
was obtained as a by-product of gold from the gold mines of the
Witwatersrand-Klerksdorp-Free State area. Uranium production in South Africa is
heavily dependent on the future of gold mining, which in turn is governed by
prevailing gold prices, exchange rates and production costs. Gold production in
South Africa is on the decline, and already fell from 580 t p.a. in 1994 to 342
t in 2004. Some uranium is also recovered from the mine tailings that have been
generated over more than 100 years at the gold mines. Although previously
associated with the gold mining industry, the Dominion mine near Klerksdorp is
now regarded as a primary uranium mine with significant future potential.
There are at least two other uranium deposits of interest which are not
associated with gold. One is the Phalaborwa Igneous Complex, from where about
5% of South Africa's total uranium production originated. Uranium production in
this case is determined by the copper mining strategy of the mine where it is
extracted as a by-product. Another potential area of interest is the Karoo
sandstones which have not been mined thus far, but where uranium deposits have
been explored in several areas. Results from drilling operations carried out
during the 1970s indicated that the resource may contain approximately 100 000
t U in various cost categories.
4.2 Resource estimates
South Africa's uranium resources which can be recovered at a production cost of
< $130/kg have been estimated at 298 000 t. That places South Africa's
reserves amongst the top four to five countries in the world. Some 60% of these
resources are associated with and dependent on gold mining, while the bulk of
the rest is in the Karoo sandstones. This figure must, however, be treated with
caution, since the published resource estimate of 298 000 t U for 2002 has
apparently not been adjusted for increases in production costs for many years.
4.3 Future needs
Uranium production in South Africa is inextricably linked to and determined by
the world uranium market prices and the local production of gold. The present
upswing in world demand and prices seems sustainable and will most likely
stimulate increased production. Total local uranium demand for a South African
nuclear energy programme consisting of the Koeberg power station and 30 PBMR
reactors would be at most 1 500 t p.a U. This is modest compared to the
extraction and processing facilities which have been retained by many mines in
operational or mothballed status from times when production was more than 6 000
t p.a.
It seems reasonable to assume that the present level of international uranium
prices, which escalated dramatically over the last two years, will result in
sufficient South African production to supply the potential future need. A drop
in international uranium prices could reduce South African production to below
local needs. Low prices, on the other hand, would imply that uranium will be
readily available on international markets and therefore also to South Africa.
When considering the security of future local uranium supply to a South African
nuclear programme, the relevant question would be whether uranium reserves, in
the long term, would be sufficient to guarantee commercially competitive
recovery of sufficient uranium for the programme. This is, under present
conditions, totally dependent on the future of gold production in the country.
As mentioned above, gold production is on the decline, and the closure of more
mines over the next 20 to 30 years seems inevitable. It would, therefore, in
the interest of long-term security of supply, be important to find and develop
alternative uranium sources which are. not so dependent on gold or other
co-products. The Karoo sandstones probably present the most promising area for
further exploration and possible future uranium mines. The new focus on the
mining of uranium as primary product in the Klerksdorp area by SXR Uranium One
as well as uranium recovery from tailings may further contribute towards
uranium production which will be less dependent on gold. It is further also
important that the uranium resource estimate be updated to allow for production
cost increases for the past 10 years.
5. URANIUM CONVERSION
5.1. Background
A conversion plant for the production of UF6, the feed material to enrichment
plants, from Ammonium Diuranate (ADU) which was supplied by South African
mines, was operated by Necsa between 1986 and 2000 as part of its nuclear fuel
production programme. The plant had a nameplate capacity of 1 200 t p.a. U as
UF6, but production was < 50% of the capacity for most of the operating
period. A production rate of 850 t p.a. U was achieved after technical
modifications in 1995. Approximately one-third of the almost 6 000 t U as UF6
produced by the plant was used as feed material for uranium enrichment in South
Africa, while the rest was exported. The Necsa plant, which included
distillation of UF6 as the final purification step, was internationally highly
regarded for the purity of its product.
After Necsa terminated its fuel production programme for Koeberg, an attempt
was made to retain the conversion plant for the production of UF6 for export.
This was not successful due to the high operational cost, and the plant was
closed in 2000. The plant is scheduled for decommissioning in future. Certain
critical components were already badly corroded at that stage, and are no
longer fit for plant use. The main reason for the poor economic performance was
the low capacity of the plant. International experience has shown that a
commercial plant should have a capacity of at least five times the nameplate
capacity of the Pelindaba plant.
The conversion process required facilities for the production of HF (from
locally mined CaF2, fluorspar) and F2 gas. The HF plant with a capacity of 4
500 t p.a. HF is still operational, and supplies HF to Necsa's commercial
fluorochemical programme for local industry and also for export. F2 is also
still being produced at Necsa for its fluorochemical business.
5.2. Future conversion requirements
Local production of fuel for 30 PBMR reactors would require a UF6 production
capacity of approximately 750 t p.a. U as UF6. Even if all of Koeberg's fuel
were produced from locally converted uranium, a total local conversion capacity
of approximately 1 000 t p.a. U as UF6 would be required.
The establishment of an economically viable conversion plant in South Africa
could therefore only be considered if the bulk of production were exported as
UF6, enriched uranium or reactor fuel, if such plants of economic capacity were
available locally. The transport penalty of exporting UF6 instead of .uranium
oxides should be further noted. Global demand for commercial conversion
services (52 000 t U as UF6 for 2005) is presently met by the five major
commercial producers. It seems likely that some existing producers (Areva, for
example) will expand their capacities to meet the expected growth in demand in
future.
5.3. Future strategies
South Africa's future needs for enriched uranium will largely be determined by
the requirements of the Light Water and PBMR power reactors. Enrichment levels
of approximately 5% will be required for Light Water Reactors and 9.6% for PBMR
reactors. Assuming a scenario where the nuclear power component of Eskom
gradually increases to 14.5% in 2030 when 5 000 MWe will be generated by Light
Water Reactors and a further 4 950 MWe by PBMR reactors, an enrichment capacity
of almost 1 500 000 SWU p.a. would be required to fuel the reactors.
There are three broad approaches which can be considered for meeting the SWU
deand:
Firstly, the construction of an independent indigenous enrichment facility in
South Africa under fulllAEA safeguards can be considered. This would, in all
probability, be based on centrifuge technology, which should provide the best
and lowest risk opportunity for establishing commercially competitive
enrichment technology in South Africa. Recent statements by South African
researchers that an improvement of the old vortex tube technology can be
expected to lower the power requirement for uranium enrichment would still
require confirmation by an extensive and costly Research and Development
(R&D) programme before any view on the competitiveness of the improved
technology for uranium can be formulated. Unfortunately most of the other
unfavourable characteristics of the process, such as the use of hydrogen as
carrier gas, will also still apply. The option of a local plant may possibly be
seen as providing maximum assurance of supply, but it suffers from serious
disadvantages such as the availability of mature competitive technology, very
high capital investment and low economy of scale, particularly matching of the
enrichment plant capacity to the growing product requirement over time. The
approach of constructing an independent plant in South Africa would certainly
result in the highest cost of enrichment services for Eskom.
Secondly, procurement of-enrichment services on international markets is
of course an option. Uranium at enrichment levels of up to 5% is readily
available from various suppliers as part of an extensive international trade
network. Security of future supply should be very high, particularly for
countries that forego the building of their own enrichment facilities. There
is, however, no diversity of supply for 9.6% enriched uranium for PBMR
reactors. The initial limited demand for this level of enrichment will also not
stimulate diversity of supply, and the programme may be dependent on a single
supplier with the associated risk. When Generation IV nuclear reactors come
into commercial production, there may be a growing demand for higher enrichment
fuel for future High-temperature Gas-cooled Reactors (HTGRs). This may lead to
a diversity of suppliers entering this market, resulting in an assurance of
supply situation similar to that in the current up to 5% services market. It
should, however, be noted that the bulk (91.4%) of the separative work required
for the production of 9.6% enriched uranium is required for taking it up to 5%.
If, therefore, 5% enriched uranium is procured on the normal market and a
single enricher (or more) is contracted to upgrade it from 5% to 9.6% (8.6% of
the total-separative work), it would not be too serious to even pay a
significant premium for this last step. A centrifuge facility required to do
the upgrading for 20 PBMR reactors would hardly be more than a laboratory scale
facility.
Thirdly, joint ownership in facilities either in the country of the technology
holder or in South Africa is an option. The plant will be financed, managed and
staffed on a multinational basis and partners of the technology holder will not
gain access to sensitive technology. Details of this type of arrangement are
still being developed, but it can be accepted that it would result in adequate
assurance of non-proliferation as well as assurance of supply. Economy of scale
would be an advantage of such a jointly owned facility. It would also require a
more manageable investment for each member state than building an indigenous
national facility. In addition, it would be suitable for enrichment levels up
to 9.6% or more.
Another possibility for the procurement of 9.6% enriched uranium which may be
worth exploring is linked to the down-blending of HEU from Russian and American
nuclear warheads. Dow-blended HEU from both sources is presently being used in
USA power reactors. The question arises whether 9.6% enriched uranium could be
obtained from the USA or Russia for the interim period until such time as this
level of enrichment becomes generally available as a result of future demand by
High-temperature Reactors (HTRs).
In conclusion, the PBMR requirement for fuel enriched to 9.6% may well turn out
to be the determining factor in deciding on a procurement strategy. It is
important that a feasible and economically acceptable strategy for the
procurement of the 9.6% enriched fuel be found and agreed with a reliable
producer in good time.
The supply of 20% enriched uranium for SAFARI-1 fuel is not addressed in this
document, since it involves very small quantities of material for which
international supply lines are well developed and secure.
6. FUEL FABRICATION
6.1. Background
South Africa-is nuclear fuel requirements for the foreseeable future will be
determined by the needs of the Koeberg Nuclear Power Station, the SAFARI-1
reactor and the PBMR programme.
Koeberg procured all its fuel requirements from Framatome (now Arera) since
commissioning of the two reactors in 1984/1985 until 1988, after which Necsa
provided the fuel until the closure of the Beva plant in 1996. The Beva plant
had a production capacity of approximately 200 fuel assemblies per annum while
the Koeberg requirement was approximately 70. The plant was closed due to cost
considerations as result of the low throughput and the negative expectations of
future growth in local demand, as well as the inability to find export
opportunities. Eskom has since procured its fuel on the open market and
recently entered into a long-term contract with Areva for fuel production, and
with Russia for the supply of the enriched uranium.
Highly Enriched Uranium (HEU) fuel for the SAFARI-1 reactor was procured from
the USA from commissioning of the reactor in 1965 until 1977, when the USA
terminated the agreement. Since 1982, SAFARI-1 fuel has been produced by Necsa
-in the Materials Test Reactor (MTR) fuel fabrication facility after locally
produced HEU became available. The South African inventory of HEU is presently
used to fuel the reactor, as well as for target plates for the commercial
production of radioisotopes. The fuel consumption of the reactor, on average 40
fuel elements containing 300 g U-235 each, is largely determined by the isotope
production programme.
Following the licence agreement between Eskom and the German PBMR technology
holder, a laboratory was established at Pelindaba, where PBMR fuel production
technology has been demonstrated on laboratory scale. Fuel spheres for irradiation
testing will be available from the laboratory by the end of 2007. The design
and licensing of a Pilot Fuel Plant (PFP) is at an advanced stage.
6.2. Future strategies
Koeberg will continue its practice of procuring fuel production and enriched
uranium on the open market. Should uranium conversion and enrichment be resumed
in South Africa, it can be expected that preference for locally enriched
uranium will be considered for the production of Koeberg fuel. It is unlikely
that local PWR fuel production will be considered in South Africa again, as a
fuel production plant would face the same obstacles as the Beva plant. Koeberg
will continue to strive for higher burn-up of fuel and would thus require fuel
with higher enrichment levels (up to 4.95%). The introduction of MOX fuel could
also be considered in future.
The SAFARI-1 reactor will, as part of the worldwide trend, convert to operation
with Low Enriched Uranium (LEU) fuel. LEU fuel implies a technology changeover
for the MTR fuel plant, and it is likely that future fuel production will be a
mix of imported and locally manufactured components. The optimum mix will have
to be determined. LEU will have to be imported in any case. That would result
in the existing HEU inventory possibly becoming available for the production of
isotope production targets only. SAFARI-1 may consider upgrading to 30 MW in
future, which would result in 30% higher fuel consumption.
PBMR fuel spheres from the laboratory facility will be irradiated in foreign
facilities as part of the fuel qualification programme. Construction of a PFP
will commence by the middle of 2007 and production will start by the end of
2009. Sufficient fuel (450 000 fuel spheres) must be available for loading the
Demonstration Power Plant (DPP) by the end of 2010. The PFP will have an
initial capacity of 270 000 fuel spheres per annum. It will be upgraded
gradually to 540 000 fuel spheres per annum and later on to even higher
capacity. The present PBMR strategy would require a fuel production capacity of
at least 900 000 fuel spheres per annum to service the equilibrium cores of
PBMR reactors by 2015. A commercial fuel plant with a capacity of at least 3.6
million fuel spheres per annum would be required to service the equilibrium
cores of six four-pack power plants for Eskom as envisaged in the PBMR
strategy. Development of a next generation PBMR fuel will be initiated in
future. It would be necessary for a fuel development laboratory to be
maintained at Pelindaba, for SAFARI-1 to be equipped for test irradiations, and
for a Post-irradiation Examination (PIE) capability to be established at Necsa.
7. NUCLEAR WASTE MANAGEMENT AND DECOMMISSIONING
7.1. Background
The following categories of nuclear waste are formed during the generation of
nuclear power:
·
The production of fuel for nuclear reactors creates
radioactive waste containing un-irradiated natural and enriched uranium from
conversion, enrichment and fuel production processes;
·
During reactor operations, small quantities of fission
products from the fuel and neutron activation products from construction
materials are recovered during decontamination of liquid and gaseous effluent
streams. This type of radioactive waste, together with redundant components, is
classified as Short-lived Low and Intermediate Level Waste (LlLW-SL) and
consists predominantly of radionuclides with half-lives of < 31 years.
·
Spent fuel assemblies contain uranium and other
actinides with long half-lives formed from uranium as well as a broad range of
fission products. This waste is classified as High-level Waste (HLW).
7.2. Strategies for South African radioactive waste
7.2.1. Koeberg Nuclear Power Station
The Koeberg Nuclear Power Station consists of two PWRs with a total capacity of
1 840 MWe. The reactors are of French origin and were commissioned in
1984/1985. Fuel containing 4.4% enriched uranium is presently supplied by
Areva. Fuel burn-up of 52000 MWd/t is being achieved. On average, 35 t of enriched
uranium in 75 fuel assemblies is required annually. The natural uranium.
requirement to fuel the power station is approximately 350 t per annum. Fuel
for the reactors was supplied by Necsa for a period of 10 years before the Beva
fuel plant was closed. The present life expectancy of the reactors is 40 years.
The extension of the reactor lifetimes to 50 or even 60 years and the possible
introduction of MOX fuel is being investigated. The enrichment level of fuel
will be increased to 4.95% in future. All spent fuel generated during the
40-year operation period can be accumulated in the spent fuel storage pools,
but more dry storage capacity would be required for longer periods of
operation.
Koeberg's solidified operational waste classified as LlLW-SL is disposed of in
shallow (10m) trenches at the Vaalputs radioactive waste repository. This is
likely to continue for the remaining life of the two Koeberg reactors.
Except for some fuel assemblies in four dry storage casks, all spent fuel at
Koeberg is stored in the spent fuel storage pools, which would be able to
accommodate the rest of the spent fuel for the full expected 40-year lifetimes
of the two reactors. Should the operational period of the two reactors be
extended to 50 years, however, the dry storage capacity of Koeberg would have
to be expC!nded to make provision for a total of almost 4 000 spent fuel
assemblies. For the likely scenario where another 40 years of dry storage,
preferably at the eventual disposal site, would be necessary after the closure
of the reactors, more .storage casks (probably a mixture of the existing Castor
casks as well as Nuhoms casks) would be required before the spent fuel would be
encapsulated for final disposal.
In the event that the reprocessing option for Koeberg spent fuel is chosen, the
removal of spent fuel from the storage pool for reprocessing could be scheduled
such that no additional dry storage casks would be required for storage, since
the waste received from the re-processor would already be contained for storage.
It should, however, be noted that both the direct disposal as well as the
reprocessing routes would eventually require a deep disposal facility as well
as a dry storage facility at the disposal site.
The above scenario for the management of Koeberg spent fuel would imply that a
deep disposal facility should be ready for final encapsulation and disposal by
about 2070.
7.2.2 PBMR Programme
Operational waste generated by the demonstration PBMR on the Koeberg site
will generally be in the category LlLW-SL. It will be handled similarly to
operational waste from the existing reactors and disposed of at Vaalputs.
Two options for dealing with spent PBMR fuel are being considered at present:
·
The first option involves the direct disposal route.
This implies on-site storage of the spent fuel for another 40 years after the
closure of the reactor, after which it can be transferred to shipping casks for
storage and disposal at the HLW repository. A multi-model plant producing 1 000
MWe will require 14 shipments per annum in standard PWR spent fuel casks.
The second option involves reduction of the HLW volume
by removing the matrix and outer pyrolytic graphite of the coated particles at
an on-site facility. The coated particles are then fed into storage casks. It
is further aimed to remove the C-14 isotope from the graphite and to reuse the
cleaned graphite for the production of fresh fuel. This option could reduce the
volume of HLW to 4% of that of the first option. The viability of the volume
reduction process has not yet been demonstrated and-development work would be
required before decisions can be made.
7.2.3. Necsa
Radioactive waste at the Pelindaba site originated from:
a. Process development and production of fuel for the Koeberg reactors as well
as HEU for the military programme. This waste is primarily in the category
un-irradiated uranium and most of it is stored in drums in the Pelstore
facility.
b. Waste associated with the operation of SAFARI-1, particularly fuel
production and spent fuel.
c. R&D and radioisotope production programmes, which are mostly short-lived
isotopes in the category LILW-SL.
Before 1996, some un-irradiated uranium contaminated waste as well as
short-lived isotope waste was buried in shallow trenches at Thabana. Since then,
Thabana has only been used as a waste storage site. Spent fuel from SAFARI-1 is
stored in the reactor pool and also in a dry storage facility at Thabana.
No radioactive waste from Necsa has thus far been transferred to Vaalputs. It
is envisaged that all waste meeting the Vaalputs Waste Acceptance Criteria
(LILW-SL at present) will in future be disposed of there. A signifiCant portion
of the un-irradiated uranium contaminated waste (LILW-LL) is not within the
Vaalputs Waste Acceptance Criteria at present. It is important that a decision
be obtained on the future acceptability of this category of waste at Vaalputs,
possibly in retrievable storage containers at depths of more than 10m. A
decision must be made on whether the existing waste in the Thabana trenches
would have to be recovered or whether it will be managed as disposed-of
radioactive waste on a permanent basis. The volume of SAFARI-1 spent fuel is
extremely low compared to that of Koeberg and the most effective disposal
method would be to follow the Koeberg approach. Provision for long-term
management and storage of radioactive waste at Pelindaba will be necessary for
waste which cannot be accepted at Vaalputs.
7.2.4. Reprocessing
According to the draft document on the Radioactive Waste Management Policy and
Strategy for South Africa, reprocessing of spent fuel should not be excluded as
an option which, if selected, would probably have to be contracted out to other
countries in view of the high cost and limited expected local demand.
Reprocessing technology for PBMR spent fuel is not yet available and it would
probably be prudent to postpone a possible decision on the reprocessing of
Koeberg spent fuel until more information is available on the future of PBMR
technology in South Africa, and on the associated reprocessing requirements (if
any) to ensure a holistic national strategy for the management of spent fuel.
7.3. Decomissioning
South Africa already gained some 10 years' experience in the decommissioning of
uranium contaminated plants through the ongoing Decontamination and
Decommissioning (D&D) programme at Pelindaba. Necsa also developed a
long-term plan and cost estimate for the D&D of its historical and some
other facilities over the next 30 years, the bulk of which will be funded by
government. Eskom is making financial provision for the decommissioning of the
Koeberg reactors, and is already planning the decommissioning process after the
closure of the reactors, probably in 2025. The present plan envisages
completion of the decommissioning process by about 2055. PBMR (Pty) Ltd is
providing guidelines for the decommissioning of the demonstration unit and
other PBMR units. It is envisaged that decommissioning will be carried out with
spent fuel stored in the spent fuel tanks to gain maximum decay advantage.
Some key guiding principles for the planning process in all cases include the
following: ensure the maximum radioactive decay time practically possible
before commencing operations; plan the D&D processes to be followed, and
estimate as far as possible the quantities of materials and types as well as
levels of contamination which must be handled; develop a funding plan; and
ensure that facilities will be available to deal with all waste streams and to
manage the resulting radioactive waste.
8. RESEARCH AND DEVELOPMENT
The PBMR programme is presently the main focus and strategic driver of all fuel
cycle related work in South Africa, and its direct and indirect needs should
therefore be a major consideration in setting the national R&D agenda in
this field. Combined with technological requirements by SAFARI-1 and all South
Africa's nuclear waste activities, R&D planning objectives should aim to
address requirements in the following broad areas:
·
A survey of resources and technology agreements to
ensure the future availability of enriched uranium for fuel fabrication;
·
The effective establishment and operation of the
demonstration reactor and pilot fuel plant;
·
The development and demonstration of next generation
technologies including maximization of South African content in the supply of
PBMR reactors and fuel in the medium and long term;
·
Cost-effective and environmentally sensitive
management of spent fuel and other radioactive waste according to national
policy and strategy;
·
The establishment and maintenance of R&D
facilities and well-trained teams of engineers and scientists in South Africa
to execute the objectives and capabilities for managing R&D projects which
may have to be done in cooperation with foreign countries.
8.1. Uranium resources
Information on South Africa's uranium resources in the various cost categories
should be updated and the future impact of uranium producers and initiatives in
uranium mining on the resource estimates should be evaluated. More information
should be obtained on the Karoo Sandstone uranium deposits, particularly the
resources in various cost categories.
8.2.Coversion technology
Strategies and planning on conversion technology should be taken against the
background that all commercial suppliers, including South Africa's former
conversion plant, apply the same proven technology for the conversion of
uranium. Conversion adds only approximately 4% to the total cost of nuclear
fuel in the fuel cycle, and there is limited incentive for development work on
cost reduction.
A study of cost structures (minimum commercial plant capacities, global trends,
markets) in the conversion business should be undertaken and a position
regarding the future of conversion in South Africa should be formulated. A strategy
to retain fluorine technology in South Africa should be considered.
8.3 Enrichment technology
It is, as was already discussed earlier in this document, unlikely that South
Africa will embark again on the establishment of an indigenous enrichment plant.
The only mechanism whereby enrichment technology could be re-established in
South Africa would be through a joint undertaking with an established
technology partner, most probably centrifuge technology, in which case the.
South African technological contribution would be limited to the provision of
non-sensitive components, UF6 handling facilities, supporting services, etc.
Negotiations on the implementation of a joint undertaking would require a core
of knowledgeable people in the field.
A strategy for the supply of 9.6% enriched uranium should also be formulated
and the approach chosen should be negotiated with prospective
suppliers/partners.
8.4. Fuel Technology
R&D in fuel technology should be focused on the production of high-quality
and cost-effective first generation PBMR fuel, and also on improving the
integrity of next generation fuel (higher burn-up and corrosion resistance as
well as reduced diffusion of fission products through the coating) as would be
required for PBMR reactors of increased efficiency and for higher temperature
New Generation Nuclear Plant (NGNP) application such as hydrogen production.
8.5. Reactor technology
In order to maintain the competitive edge achieved by the PBMR design relative
to the norms set for the next generation nuclear reactors, technological
development will be required in several areas, including the following:
·
Improvement of reactor efficiency by developing tools
for plant design optimization and conditioning technology to improve graphite
radiation resistance;
·
Minimization of radioactive waste generation and
personnel exposure to radiation by limiting the transfer of radionuclides to
the power conversion system;
·
Improvement of the inherent characteristics and
applicability of the reactor for New Generation Nuclear Plant (NGNP)
applications.
8.6. Radioactive waste and decommissioning technology
R&D needs for the effective long-term management of existing Low and Intermediate
Level Waste (LlLW) in South Africa are low. Technology for the processing and
disposal of short-lived LlLW (LlLW-SL) is well established and is dealt with on
a routine basis. Processing technology for un-irradiated uranium containing
waste in the category LlLW-LL is also well established, but no disposal
methodology has been licensed as yet. Finalization of this matter would require
the design, safety assessment and licensing of a facility at a suitable site,
probably Vaalputs. Management of radioactive waste arising from the PBMR
programme will, due to its uniqueness and special requirements, however,
require the development of special technologies. High-level Waste (HLW),
predominantly spent fuel from the Koeberg power station and SAFARI-1, would use
internationally developed best practices whether being directly put into final
storage, or being reprocessed.
8.6.1. PBMR Radioactive Waste
Waste minimization and reuse of certain materials are the main drivers of
technology development for PBMR radioactive waste. This would imply the
separation of coated particles from spent fuel spheres and the reclamation of
matrix graphite. HLW originating from the PBMR programme will be dealt with
similarly from a. policy perspective to other HLW in South Africa.
8.6.2. High-level Waste
There is as yet no HLW disposal methodology or facility for dealing with this
category of waste from Koeberg, Necsa or the PBMR. Planning of R&D work on
the preparation of HLW for final disposal must await finalization of the
national policy and strategy on radioactive waste, particularly with regard to
reprocessing. The draft policy and strategy document does, however, indicate
that investigations for the establishment of a deep geological facility must go
ahead in the interim. This directive would imply that work be initiated on the
selection of a suitable site (which could be Vaalputs), the conceptual design
of a repository, as well as geological modelling and associated studies to
support the safety assessment and licensing of the facility.
International knowledge and experience of radioactive waste technologies,
particularly HLW, are generally readily accessible through the IAEA and other
international forums. Inputs from such sources are most valuable and should be
fully exploited in support of local activities. The key would be to establish
and maintain a group of experts who would be able to absorb the international
information and apply it locally.
8.6.3 Decommissioning
Decommissioning and the associated decontamination technology of non-irradiated
uranium contaminated equipment is well established in South Africa and hardly
merits supporting R&D. Present work in this field presents an ongoing
learning experience in the optimal synchronization and costing of the full chain
of activities, as well as the estimation of the full nuclear liability
associated with plants and equipment.
Decommissioning experience of equipment contaminated with actinides and fission
products, as found in nuclear reactors, is limited in South Africa.
International experience in this field is growing rapidly and technical
information is generally shared widely between countries. It can realistically
be assumed that with the aid of existing D&D experience in South Africa as
well as information from international sources, it should be possible to plan
and execute an effective D&D programme if reactor personnel with
operational experience and knowledge of plant hazards are involved in the
project.
9. CAPACITY BUILDING
9.1. Background
An extensive and high-level human resource capability in nuclear science
and technology was established in South Africa in the past as part of a broad
range of R&D programmes and nuclear services, as well as fabrication and
production facilities. The most notable of these are the following:
·
The activities at Necsa, where people gained
experience in research reactor operation and applications; isotope production
and applications; radiation applications; various scientific and technological
R&D programmes; uranium conversion and enrichment as well as nuclear fuel
production; decontamination of nuclear facilities; nuclear waste management and
disposal; nuclear component design and manufacturing technology; and nuclear
regulation and safety. -
·
iThemba Labs, which provide experience in accelerator
construction, operation, maintenance and application for nuclear particle
physics research, isotope production and particle therapy of patients.
·
Operation and maintenance experience of PWRs at
Koeberg.
·
Regulatory experience of nuclear facilities and mines
at the National Nuclear Regulator (NNR).
·
Various universities, hospitals and clinics which
provide experience and training in nuclear sciences as part of academic
curricula, accelerator applications, medical applications of isotopes and
radiation, and radiation protection training.
·
More recently, the launch of the PBMR programme
created an exciting and demanding new earning opportunity for the South African
nuclear sector. Significant experience has been gained with high-temperature
power reactor design, as well as laboratory scale fuel fabrication. An
extensive international technological support network with the associated
skills transfer opportunities has also been established.
Apart from a number of facilities which were closed
down at Necsa, all the other activities referred to above are still an ongoing
part of the national nuclear Science and Technology (S&T) human resource
capability. The rapid growth in the human resource requirements of the PBMR
programme as well as the need for transformation in existing institutions have,
however, created a high demand for suitably qualified persons which are presently
just not available in the nuclear sector. The existing training capability is
further insufficient to meet the demand and several actions aimed at rectifying
the situation have been initiated in the recent past.
9.2. Future Strategy
The following existing and planned training opportunities will be available for
addressing the shortage of skilled workers in the nuclear sector.
9.2.1. Existing Nuclear Focused Postgraduate Qualifications at Universities
- North-West University (Mafikeng)
The Centre for Applied Radiation Science and Technology (CARST) presents a
two-year MSc degree in radiation sciences and technology. The first year is
fulltime study at the university followed by a year at a nuclear institution
during which experimental work is done for a dissertation.
- North-West University (Potchefstroom)
Two Masters' programmes in nuclear engineering for candidates holding BEng and
BHons degrees are offered on a distance contact basis (including one lecture
week per course) which enables full-time workers to participate. Courses are
presented by local and international experts. The university is a member of the
World Nuclear University. The engineering faculty developed and operates a
physical model of the PBMR power conversion unit, which also serves as a useful
tool for postgraduate training. (Refer to Appendix I for more information.)
- Masters in Accelerator and Nuclear Sciences
The two-year course is presented jointly by the universities of Zululand and
the Western-Cape together with iThemba LABS. The first year is full-time study
at the universities for an Honours degree followed by a year at a nuclear
institution where experimental work is done for a dissertation. Students can
specialize either in accelerator science (MANUS) or material science (MA TSCI).
(Refer to Appendix I for more information.)
- Witwatersrand University
The university offers two postgraduate courses. A course on radiation
protection and safety follows the syllabus of the IAEA on this subject. It is
an 18-week fulltime course. The other course on physics, engineering and
safety of nuclear power reactors is normally given at Koeberg and requires
full-time study of about 22 weeks. Industrial visits to SAFARI-1, the
micro-model of the PBMR power conversion unit and the PBMR fuel development
laboratory are included. (Refer to Appendix I for more information.)
- PHRIF
The PBMR Human Capital Research and Innovation Frontier (PHRIF) Programme was
initiated by the Department of Science and Technology (DST) in conjunction with
the nuclear industry in 2004. Although the programme is primarily focused on
the human resources needs of the PBMR programme, it is evident from the list of
projects that the whole nuclear industry will benefit from it.
The projects include support to grade 10, 11 and 12 pupils from disadvantaged
areas to study science and mathematics; bursary support to undergraduate,
masters, doctoral and postdoctoral students; the sponsoring of eight research
chairs in PBMR-related technologies at South African universities; sponsoring
of conferences; and networking for communities of practice in the nuclear
sector. Programme funding for the next 10 years will amount to a total of R230
million. Although the research chairs will be focused on topics of particular
interest to the PBMR programme, several of these will also be of interest to
the broader nuclear industry. (Refer to Appendix I for more information.)
- Other Courses
- IAEA
Local capacity building can further benefit by a broad range of IAEA-sponsored
initiatives such as:
·
The fellowship scheme, whereby fellows from South
Africa can receive on-the-job training at foreign institutions for periods of
up to one year.
·
AFRA workshops in South Africa or elsewhere in Africa
where workshops, normally lasting one to two weeks, on various topics such as
nuclear waste, and research reactor, medical and agricultural applications, are
presented by recognized international experts.
10. INDUSTRIALIZATION AND LOCALIZATION
10.1. Introduction
The decision of the South African Government to support and finance the
development of the Pebble Bed Modular Reactor (PBMR) was partially based on the
economic and developmental advantages to South Africa - in addition to the
provision of electric power. The future local and international sales provide a
significant industrial and skills development opportunity for South Africa.
PBMR (Pty) Ltd has consequently embarked upon an aggressive industrialization
and localization drive in order to maximize the economic and technological
opportunities for South Africa.
10.2. Supply chain
a. Following the successful completion of the demonstration unit, PBMR intends
supplying pebble bed reactors to the local and international market.
b. The first 'commercial' units are scheduled for delivery to Eskom in 2018,
and can thereafter be supplied at a rate of three per annum;
c. To support this programme and. the export market potential, PBMR must:
i. Establish a secure an
internationally competitive supply chain capable of delivering six pebble bed
reactors per annum;
ii Maximize South African local content which is economically justifiable
and-sustainable,-and-technically-achievable
10.3 Localization initiative
10.3.1. Objective of Localization Initiative The objectives of the localization
initiative are:
1. Active participation in the establishment of an economically viable and
sustainable nuclear industry in South Africa.
2. Skills development, job creation and Black Economic Empowerment (BEE)
through the nuclear industry.
3. Export promotion of capital goods and value-added products.
4. Promotion of local industrial capacity and capability and the support of
Small, Medium and Micro Enterprises (SMMEs) where possible. The promotion of
manufacturing improvements and R&D- in order to remain internationally
competitive.
5. Promotion of technology transfer, joint ventures, new trading partners and
foreign investment.
10.3.2. National Industrial Participation Programme
The National Industrial Participation Programme (NIPP) of the Department of
Trade and Industry (DTI) constitutes an important mechanism whereby
international suppliers will be obliged to formulate programmes which would
benefit the South African economy.
10.3.3. Steps to establish a South African support industry for PBMR
The following steps have been identified in a localization initiative to
establish a South African support industry for PBMR:
a. Industrial development
- Recapitalization of the heavy industry capability in South Africa.
-New industrial development for capabilities that do not currently exist.
- Industrial upgrade of existing industries that could potentially deliver
components to PBMR.
- Significant NIPP opportunities.
- Production technology R&D.
- Competitiveness and cost reduction strategies.
- Optimized logistics and consolidation.
- International benchmarking.
b. Skills development
- Must be linked to other skills development programmes to support all the
capital projects in the country.
- University and technikoneducation
- Artisans - especially in welding and machining.
- Learnership Programmes.
- Mentoring Programmes.
- Project-specific Training Programmes.
- International Exchange Programmes.
c. Scientific and technological development
- Technology transfer (important NIPP opportunity).
- Establishment of Centres of Excellence at universities as well as the
identification of networks of expertise countrywide.
- Local R&D.
- Contracted R&D.
- Optimum utilization of existing facilities, i.e. Necsa, CSIR.
d. Quality assurance
- Re-establishment of quality assurance programmes and disciplines with the
required procedures and documentation.
- Reskilling of manufacturers.
- Promotion of safety culture.
- Training f<?r manufacturers and inspectors.
- ASME and other international certification suitable for the nuclear industry.
e. Corporate structures
- Adequate corporate structures for large and technically advanced local
manufacture.
- Viable corporate structures that will be able to support the long-term
strategic goals of PBMR.
- Partnerships and joint ventures.
- Local and foreign direct investment.
f. Black economic empowerment
- Many equity opportunities in local manufacture.
- BEE procurement.
- Training and educational initiatives.
g. SMME development
- Many support services.
- Support of local communities during construction.
- Long-term relationship with local communities during operation and
maintenance of plants.
h. Appropriate financial structures
- Investment finance through the Industrial Development Corporation (IDC) and
other financial institutions.
- Strategic investments.
- World Bank and International Development Banks.
- Incentives.
- Cost of finance - especially in the face of financial support provided by
other governments to their industries.
- Export credit guarantees.
i. Government support mechanisms
The government, through DTI, has instituted various support mechanisms for
industrial development such as:
- strategic-Investment Programme-(SIP)
- Support Programme for Industrial Innovation (SPII).
- Technology and Human Resources for Industry Programme (THRIP).
- Competitiveness Fund.
- Support for quality assurance upgrades.
- Customs relief for capital imports.
- Export incentives.
- Industrial Development Zones (IDZs).
ii. These programmes may have to be revised in order to support the PBMR
requirements, and some entirely new programmes may have to be defined and
agreed