Safe and secure management of sealed radioactive sources in Ghana:

status of the borehole disposal project

G. Emi-Reynolds, E.T. Glover, M. Nyarku*, P. Essel, Y. Adjei-Kyereme

Ghana Atomic Energy Commission (GAEC)

Outline

• Introduction

• Regulatory regime

• Management of radioactive sources in Ghana

• The borehole disposal project

• Conclusions

Introduction

The use of radioactive materials in Ghana began in the mid 1950s in the then University of College of Gold Coast (now the University of Ghana).

Radioactive sources have since been in use in various sectors of the Ghanaian economy (medicine, agriculture, industry, research and academics)

Nuclear medical - radiotherapy, diagnostics, equipment sterilization

Food processing - food preservation & shelf-life extension through irradiation

Mining companies - nuclear gauges, radiography machines

Brewery companies - nuclear gauges

Oil logging & refineries - nuclear gauges, neutron radiography machines

Construction companies - nuclear gauges, radiography machines

Smoke detectors;

R&D laboratories - calibration sources, gamma and neutron irradiators

Regulatory regime: regulatory authority

• The Radiation Protection Board (RPB) is the statutory regulatory authority in Ghana that regulates all practices involving radiation and radioactive sources;

• The RPB was established in 1993 by PNDC Law 308;

• Draws its powers and functions from the Radiation Protection Instrument (LI) 1559 of 1993;

• The RPB has an administrative support unit called the Radiation Protection Institute (RPI) that provides day-to-day administrative support to the Board

Regulatory regime: powers and functions of the regulatory authority

The RPB in exercise of its powers and functions among other things:

registers all radioactive sources in Ghana;

issues licenses, authorizations and permits for all activities involving radioactive sources (e.g. import, export, transport, use, operation of facilities, etc);

inspects radiation sources and facilities;

makes regulations in respect to management of disused sealed radioactive sources (DSRS) in Ghana;

develops Safety Guides in respect of general management practices for radioactive sources in Ghana (the GRPB-G series)

Management of radioactive sources in Ghana

• The National Radioactive Waste Manage Centre (NRWMC), is the established body for the management of radioactive waste materials in Ghana;

• The NRWMC operates a Centralized Radioactive Waste Processing and Storage facility;

• Has established a database for disused sealed radioactive sources in Ghana

Management of radioactive sources in Ghana: the centralized waste storage facility (CWSF)

Management of radioactive sources in Ghana (cont’)

• When a radioactive source (RS) is declared disused by the user, the user is required to repatriate the disused source to the supplier or transfer its management to the NRWMC;

• The transfer requires authorization from the Regulatory Authority;

• The user applies officially to the NRWMC for management of the source;

• The DRS is subsequently transported to or received at the CWSF after ensuring that it meets the facility’s acceptance criteria

Management of radioactive sources in Ghana: nature of sealed sources in store

Sealed radioactive sources in store at the CWSF include:

conditioned (Ra) sources (in drum);

unconditioned sources (mainly gauges, medium &

small sized sources);

unconditioned high activity sources (food irradiator, teletherapy head and gamma radiography source)

The Borehole Disposal Project

• Due to the half-lives of the radionuclides in store and the threat to national security, storage is considered not a sustainable option for management of DSRS, hence the need for a disposal facility;

• Considering the small waste volumes of Ghana, there is the need for: - small volume repository - simple but safe technology - economically viable concept

• Ghana has expressed the willingness to exploit the Borehole Disposal Concept developed in South Africa under the IAEA TC Project for disposal of the disused sealed sources

The borehole disposal project: technical & safety aspects

The borehole disposal project: technical & safety aspects (cont’)

• DSRS is sealed in a 3 mm thick 304 stainless steel capsule which is 110 mm long and 22 mm in diameter and the lid welded

• The capsule is then placed in a hole in a

pre-cast concrete in a 316L stainless steel container which is 114 mm diameter and 250 mm long

Activities

Review of existing document /information;

Geophysical Investigation and preliminary site characterization;

Updating waste inventory;

Developed technical specification and contract document for site investigation;

Developed Project Management System;

Preliminary Safety Assessment for the Borehole Disposal Concept in Ghana;

Human resources development – Fellowships, Scientific visits, training courses, expert missions

Drilled Boreholes

• Two exploratory boreholes ( 150m) each for detailed site characterization have been drilled

Conclusion

Efforts are being made to develop a comprehensive regulatory and radioactive waste management infrastructure for safe and secure management of sealed radioactive sources in Ghana;

The Borehole disposal concept for disposal of disused sealed radioactive sources when implemented will ensure the safe disposal of disused radioactive sources in the country.

Thank You