2. 2
South Africa is an IAEA Non Proliferation Treaty Member State for
promotion of nuclear for peaceful purposes.
The scrap metal consist of uranium contaminated ferrous and no-
ferrous metals which are currently stored on the Pelindaba site
This contaminated materials pose a safety risk and to reduce the
risk, melting was considered as an option
The challenge with these materials is that they cannot be
adequately decontaminated by the conventional methods that are
available to Necsa on the Pelindaba site
Continues
Background
3. 3
Background (Continued)
Necsa embarked on a comprehensive techno-economic
study to look at all the alternatives to safely manage the
material according to international waste management
practices.
Alternatives considered : Store indefinitely, encapsulate
and store at Necsa, shredding, direct disposal, melting at
commercial smelter.
The Smelter will be exclusively used for Necsa metals
currently on site.
4. 4
Objectives of Smelter
To decontaminate materials which cannot be
decontaminated with the use of conventional methods.
To reduce the waste volumes substantially.
To destroy sensitive equipment associated with nuclear
non-proliferation.
Improve waste management and control.
Minimize the transport of waste
Cost-effective discharge of nuclear liability.
5. 5
Examples of Smelters being used for
Decontamination
Smelters are widely used in the nuclear industry as a
waste management tool. The following countries have
smelters -
– CARLA Plant, Siempelkamp, Germany (start 1989).
– STUDSVIK Melting Facility, Sweden (start 1987).
– INFANTE Plant, Marcoule, France (start 1992).
– Scientific Ecology Group (SEG) Plant, Oak Ridge, USA
(start 1992).
– Capenhurst Melting Facility, United Kingdom (start 1994).
– Manufacturing Sciences Corporation (MSC), Oak Ridge,
USA (start 1996).
6. 6
Dimensions of a Proposed Smelter
Height : 3m
Width : 2m
Crucible : Ø 850mm x 1100mm
Load capacity:
- 4000kg steel components
- 1500kg Al and other metals
8. 8
Materials to be Processed
• The contaminated items
to be smelted comprise
a variety of components
including –
– Pipes and tubes
– Heat exchangers
– Electric motors
– Compressors
– Instrumentation
– Bolts, nuts and couplings
Material Type
Estimated Mass
(Tons)
Steel components 8 649
Stainless steel
components
1 107
Aluminium components 1 421
Cast Iron 1 075
Non-ferrous metals 1 748
Total 14 000
Most of the above-mentioned material have already gone through a decontamination process
12. 12
Smelter Location
The selected area will have the following advantages:
– It is adjacent to the proposed low and intermediate level
storage area. This is logically favourable and will minimise
transport and handling of contaminated scrap.
– Space is available for cutting and selection of scrap.
– Space is available for temporary storage and melt-refined
product.
– Most of the required infrastructure is available for example:
o Off-gas stack with monitoring facility next to area.
13. 13
Smelter Specification
An induction furnace is proposed since this is the most versatile
and will create the least off-gases.
The basic crucible size is determined by the size of the
separation elements. The objective being that these can be
melted with a minimum of prior mechanical handling e.g.
cutting to reduce size.
The smelters must have the flexibility to melt the full range of
possible materials i.e. Steel, Copper and Aluminium.
This will require two crucibles of 4 000kg each.
Full capture fume hoods connected to an off-gas filtration
system.
Continues
14. 14
Smelter Specification
Melting temperatures must
range between 700OC and
1600OC to accommodate
the various metal types.
A small 125kg test smelter
will also be installed for
experimental purposes.
An emergency sand filled
liquid metal catchment pit
underneath the furnace will
be provided.
16. 16
Smelter off-gas System
The smelters will be equipped with full capture fume hoods. These
will be connected to a separate off-gas system with own fans, pre-
filters and HEPA filters (absolute filters). The system will tie into the
existing building ventilation system and exhaust through an existing
stack (82m high).
This system is the most sophisticated offered by the off-gas suppliers
and will capture about 99,9% of the dust generated during the
smelting process.
17. 17
Test Smelter
This smelter will not operate on a continuous basis, but only as
required. Typical activities will include:
– Sampling tests with different scrap batches to evaluate
decontamination, off-gas generation and other safety-
related issues prior to full scale melting.
– Dilution tests with various scrap samples to plan full-scale
operations.
– Monitor releases into the building and through the stack.
– Train personnel on small-scale operations before letting
them operate the large smelters.
18. 18
Waste and Atmospheric Emissions
All releases of materials will be handled strictly in
accordance with the requirements of the National
Nuclear Regulator, based on international standards.
The following products and emissions will result from the
smelter operation:
– Metal ingots
Ingots not meeting the requirements of unconditional
release will be stored in the Pelstore (licensed storage
facility). It could either be conditionally cleared (re-
use or re-cycle) or disposed of at a later stage.
Continues
19. 19
Waste and Atmospheric Emissions
– Slag
The slag will trap most of the radioactivity (about 98%) and it will be drummed
(compaction could also be done) and stored in the Pelstore. Eventually it will
be disposed of at Vaalputs, the licensed disposal facility near Springbok.
– Off-gas dust used off-gas filters and used crucible linings.
These would be drummed and stored in the Pelstore until disposal at
Vaalputs.
– Off-gas emissions
The Annual Authorised Discharge Quantities (AADQ) for routine gaseous
discharges of uranium at Necsa is set by the NNR at 8 x 109Bq which relates
to an associated dose of 2μSv/a at the site borders.
20. 20
Total Accumulated Waste
• Slag ~ 500 ton
• Dust, filters, linings ~ 150 ton
• Non-cleared ingots ~ 0 – 2800 ton
• Total waste ~ 650 ton estimated
• Volume reduction of waste – 85%-95%
20
21. 21
Safety Features of the Furnace and Ancillary
Equipment
The following safety features will be built into the 4 ton and test
smelters:
– Every motor shall be provided with a freestanding emergency
stop.
– An interlock is provided preventing the furnace from being
operated unless there is sufficient flow of cooling water.
– The off-gas system contains an interlock that prevents the
smelter to start up unless the off-gas system is operational.
– A cooling water valve will be provided inside the smelter facility
to isolate cooling flow in case of a pipe rupture in the system.
– A remote emergency stop for the smelters will be provided.
– An earth leakage system for the furnace lining will be provided.
– All equipment shall be properly earthed.
Continues…
22. 22
Alarms will be provided for low cooling water and hydraulic
pressures.
All electric wiring will be done to SABS standards.
Applicable requirements of the Occupational Health and Safety Act
will be complied with.
All statutory requirements for pressure vessels and pressure piping
will be complied with.
All hydraulic and water piping will be provided with vent and drain
points.
After installation all pressure vessels and piping will be pressure
tested.
The supplier will perform a functional and melt rate test after
installation before acceptance of the equipment.
Safety Features of the Furnace and Ancillary
Equipment
23. 23
Environmental Impact
An annual dose of about 8.0 x 10-4 µSv for U at the Pelindaba site borders will
cause no environmental impact to the vicinity.
The actual mass of the uranium related to the emissions will be in the order of
120 grams per annum.
The radioactive dose to any human living in the Gauteng area, resulting from
natural sources (cosmic radiation, terrestrial, radon gas etc.) is about 2500
µSv per annum.
The added dose from the smelter at the site border will be less than one
millionth of that, and further away from the site it will become even less.
The dust and dose increase to the Necsa site and environment is therefore
insignificant and the public will not be affected by the emissions from this
smelter.
Record of Decision was issued on 31 August 2007 and valid for 5 years
24. 24
Limiting Operating Conditions
The DEA RoD was issued with strict conditions, provisions and the
implementation of various mitigation measures concerning the operation of
the smelter. Some of these include the following:
– Necsa must ensure that an emission detection system is installed in the
stack before operation commences.
– All monitoring and test results of the test smelter must be presented to the
Pelindaba Safety Information Forum (PSIF) before commissioning of the
main smelters.
– Monthly progress and audit reports concerning specified compliance and
monitoring results must be presented to the PSIF during operation of the
main smelters.
Six monthly reports concerning all operational monitoring results must also be
submitted to the DEA for a period of two years after commissioning.
26. 26
NNR Public Hearings
• In accordance with the provisions of
section 21 (4) (b)of the National Nuclear
Regulator Act, Act 47 of 1999 a public
hearing was convened by the NNR related
to the proposed Necsa smelter.
• The public hearing was held at Royal
Elephant Hotel and Conference Centre
(Bondev House) in Centurion on 11 October
2012.
• The hearings were presided on by a panel
comprising Mr D Elbrecht and Mr K
Maphoto from the NNR Board and the NNR
Programme Manager, Mr T Pather.
27. 27
NNR Public Hearings
• The following persons registered as interveners and made
oral representations at the public hearings –
– Judith Taylor (Earth life Africa)
– Robert Garbett ( Karee trust, Professional aviation Services,
Renosterspruit Nature Reserve)
– Christine Garbett (Cane, Pelindaba Working Group)
– Dominique Gilbert (Pelindaba Working Group)
• In addition a number of individuals submitted written
representation objecting to the granting of the nuclear
installation licence to Necsa.
29. 29
NNR Public Hearings
• The interveners objected to the granting of the Nuclear
installation licence for the proposed Necsa smelter citing-
– fear that the public would be impacted negatively by
the releases from the proposed facility;
– Necsa should have considered further alternatives to
smelting;
– Concern over the volume of electricity needed for the
project;
– Concern over the reliance on and reliability of HEPA
filters to be used in the facility;
– Concern over the claimed efficiency of the smelting
process to decontaminate the scrap metal.
30. 30
NNR Conclusions
• The NNR has concluded that the proposed
facility is –
- justified and in line with the Radioactive
Waste Management Policy and Strategy for
the Republic of South Africa (2005),
- appropriately designed, and
- would not represent an undue risk to workers
or the members of the public.
Continues
31. 31
NNR Conclusions ( Continued)
• The above conclusions are based on the fact that
–
The safety case documentation submitted by Necsa has demonstrated
compliance with the NNR regulations on Safety Standards and Regulatory
Practices, Regulation R.388 of 2006.
– The smelter equipment is of proven industrial design and is commercially
available.
– The projected doses to members of the public as a result of normal
operations is well below the regulatory criteria
– The maximum worker doses due to normal operations in the facility was
projected to be of the order of 5 mSv/a, which is within the prescribed
worker dose limit
– HEPA filters are commonly employed to control particulate matter emissions
from processes that involve management or treatment of radioactive
materials. The HEPA filters to be used by Necsa in the proposed Production
Smelter will be of nuclear grade and will be designed and manufactured to
international standards (such as ASME AG-1).
32. 32
NNR Regulatory Decision
• On 2 July 2013 the NNR has
granted approval for the Necsa
Production Smelter (NIL- 29
Variation 1)
• The approval will however be
implemented in a phased manner.
• The current approval is for
construction and cold
commissioning of the facility only.
• Approval for hot commissioning of
the facility will be granted separately
following NNR review of the as built
plant and results of the cold
commissioning programme.
Continues
33. 33
NNR Regulatory Decision (Continued)
• Approval for routine operation of the facility will be
subject to separate NNR approval, following review
of the results of successful cold and hot
commissioning of the facility as well as an updated
safety case reflecting the results of both the cold
and hot commissioning programmes.
• The material permitted to be smelted in the facility is
limited to the 14 000 tons of metal detailed in the
safety case. No additional material may be smelted
in the facility.
• Should Necsa wish to smelt additional material in
the facility this will be subject of a new nuclear
authorization application and will entail a process of
public consultation.
34. 34
NNR Regulatory Decision ( Continued)
• The Nuclear Installation License NIL-29 has accordingly been
amended to permit –
- construction and cold commissioning of the Production Smelter
- The receiving of non-Contaminated scrap to be used in the cold
commissioning.
The amended NIL-29 further requires that –
- Cold Commissioning of the Production Smelter must be
undertaken in accordance with an NNR approved cold
commissioning programme.
- Only non-contaminated scrap may be used in the cold
commissioning of the Production Smelter in Area 26.
- The licensee may not proceed to hot commissioning without prior
NNR approval.
