South Africa: experience of radioactive waste (RAW) management and contaminated site clean-up

W. C. M. H. MEYER, G. R. LIEBENBERG and B. VD L. NEL, South African Nuclear Energy Corporation (Necsa), South Africa

DOI: 10.1533/9780857097446.2.636

Abstract: This chapter describes the development of radioactive waste (RAW) management policies in South Africa and the implementation of such policies during contaminated site clean-up.

Key words: nuclear fuel cycle, nuclear waste, waste management, waste classification, nuclear reactor programme decommissioning.

20.1 Introduction

The main generators of solid radioactive waste (SRAW) in South Africa are the South African Nuclear Engergy Corporation (Necsa), Koeberg Nuclear Power Plant (NPP) and the mining industry. The other generators such as the iThemba Accelerator facilities, hospitals and industries are regarded as minor contributors (Fig. 20.1).

The South African nuclear programme of the 1970s to mid-1990s (mainly practiced at Necsa) has left the country with liabilities with regard to redun­dant, radioactively contaminated equipment, buildings and radioactive waste (RAW). RAW management policy in South Africa is structured and implemented by including the applicable sections from the various National Acts, i. e. National Environmental Management Act (No. 107 of 1998), The National Nuclear Regulator Act (No. 47 of 1999), the Nuclear Energy Act (No. 46 of 1999), the Hazardous Substances Act (No. 15 of 1973), and the National Water Act (No. 36 of 1998).

Radioactive wastes in South Africa are divided into two categories: his­torical waste and current/future waste. Historical radioactive waste, the main producer of which was Necsa, was generated prior to 1987. Necsa (South African Nuclear Energy Corporation) is a multi-facility nuclear site that operates or has operated the processes involved in the front-end of the nuclear fuel cycle (NFC) and therefore excludes the reprocessing of spent fuel (SF). The South African nuclear programme started in 1948 and focused on research and development in the NFC and in military applications. Some highlights in the history of Necsa are the successful separation of uranium

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Pietersburg

20.1 Locality map of South Africa showing Vaalputs, Koeberg and Pelindaba [1].

isotopes and the start of the uranium enrichment programme that included the uranium conversion facility (Fig. 20.2). The enriched uranium was used as fuel for the SAFARI-1 research reactor, the NPP at Koeberg and for military purposes.

The uranium conversion and enrichment research and production projects were terminated in the early 1990s, due to cost considerations. As stated above, the South African nuclear programme of the 1970s to mid — 1990s has left the country with liabilities with regard to redundant, radio­actively contaminated equipment and buildings and RAW. Necsa has been generating RAW since the commissioning of the SAFARI-I research reactor in 1965, and the waste includes fuel fabrication waste as well as uranium conversion and enrichment historical waste.

The bulk of Necsa ’s waste was, however, generated between 1970 and 1998 by the nuclear fuel production cycle, namely the uranium conversion, enrichment and fuel fabrication plants. The medical isotope production centre, the hot cell facilities, laboratories, decontamination facilities, etc., have also contributed significantly to the waste quantities. Necsa also accepted industrial and medical radioactive waste from smaller waste pro­ducers in the nuclear industry and the medical sector.

The bulk of Necsa ’s radioactive waste (intermediate-level waste, ILW, and high-level waste, HLW) is currently stored in various interim storage

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20.2 Uranium conversion plant at Necsa [1].

facilities on the Necsa site (Fig. 20.3). These wastes are mostly contained in metal and concrete storage containers. The waste in containers varies widely in type (powders, filters, oil, etc.) and only ILW is encapsulated into a cement waste form. These wastes can be regarded as historical waste in that they were produced in the absence of a well-defined end-point (repository) and therefore in the absence of formal waste acceptance criteria.

The main generators of current/future SRAW in South Africa are Necsa, Koeberg power plant and the mining industry. The other generators such as the iThemba accelerator facilities, hospitals and industries are regarded as minor contributors. Koeberg generates low — and intermediate-level waste (LILW) and ILW that is sent to the national waste disposal site called Vaalputs, situated in the Northern Cape (Fig. 20.4). Koeberg also generates HLW. Currently, all the HLW (SF) is stored in the SF pool at Koeberg (Fig. 20.5). Dry storage of HLW (SF) at Vaalputs as an interim solution could be considered.

Current and future nuclear activities at Necsa will continue producing operational radioactive waste, albeit in a more controlled manner to comply with formally defined waste acceptance criteria [ 2]. Current activities at Necsa that generates waste are:

1. Nuclear fuel cycle

• Uranium conversion (future)

• Uranium enrichment (future)

• Fuel fabrication (future)

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(a)

 

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(b)

 

20.3 ( a, b) Main dry storage facility at Necsa site [1].

 

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20.4 Vaalputs disposal site [1].

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20.5 Storage of HLW at Koeberg [1].

• Fuel reprocessing (future)

• Decommissioning (current and future)

• SAFARI (current materials test reactor (MTR) in South Africa)

2. Supporting facilities

• Laboratories

• Research and development

• Hot cells

• Maintenance

3. Current operations

• SAFARI 1 (research reactor)

• Nuclear technology products (NTP — production of radionuclides)

• Target plate manufacturing

4. External

• Health care waste

• Industrial waste

• Spent sealed radioactive sources

5. Decommissioning waste

• The research reactor utilized in the process for the generation of radioactive isotopes for industrial and medical applications

• The liquid waste treatment facility producing sediment that is con­ditioned and classed as SRAW

• Research laboratories

• Fuel and target plate manufacturing centre

• Decontamination facility

• Various decommissioning projects.

The Radioactive Waste Management Policy and Strategy [3] for the Republic of South Africa was approved by cabinet in November 2005, in which certain structures are to be established:

• National Committee on Radioactive Waste Management (NCRWM),

• Radioactive Waste Management Institute, and

• Radioactive Waste Fund

On a strategic level, the National Radioactive Waste Management Policy and Strategy (NRWMPS) expresses the national commitment towards the management of RAW in order to ensure a coordinated and cooperative approach to RAW management and to provide a national strategy and framework for the development of future waste management plans. Legisla­tion is currently being prepared to establish the National Radioactive Waste Management Agency (NRWMA) as an independent government- sponsored agency responsible for the disposal of all RAW on a national basis. This agency is expected to be in operation within the next three to five years.

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