1. Preparatory Work at the Regulatory
Preparatory Work at the Regulatory and Operational level for Implementation of the Borehole Disposal System for Disused Sealed Radioactive Sources in Ghana
Eric T. Glover Radioactive Waste Management Centre Radiation Protection Institute Ghana Atomic Energy Commission Ghana

2. Outline Introduction Regulatory Framework Radioactive Waste Management
The borehole disposal project
Site Characterization
Conclusion- Ongoing Tasks

3. Introduction
The use of radioactive materials in Ghana began in the early 1950s in the then University College of Gold Coast (now the University of Ghana).
Radioactive sources have since being in use in various sectors of the Ghanaian economy (medicine, agriculture, industry, research and teaching)
Ghana Atomic Energy Commission (GAEC) was established by an Act of Parliament (Act 204) in 1963 which has been superseded by Act 588, 2000.
The main functions of the Commission include the promotion, development and peaceful application of nuclear and biotechnology techniques for sustainable development in Ghana.

4. Legal And Regulatory
From 1993 to 2015 the Ghana Atomic Energy Commission (GAEC) carried out nuclear regulatory functions with the establishment of the Radiation Protection Board (PNDC Law 308, 1993)
The Radiation Protection Board (RPB) was empowered by the Radiation Protection Legislative Instrument (LI) 1559 of 1993;
RPB responsibilities include:
development of regulations and guidance documents
Issuance of licenses and authorizations for all activities involving radioactive materials
Inspections, monitoring and enforcement
making recommendations to Government

5. Management of Radioactive Waste
The National Radioactive Waste Management Centre (NRWMC) was established in 2000 to carry out the following:
Safe and secure management of all radioactive waste materials generated in Ghana
Establish facilities for the management of the radioactive waste materials
Research activities to ensure safe management of radioactive waste.

6. Radioactive Waste Management -Practice
With the collaboration of RPB, NRWMC collected a number of radioactive waste materials from users
The radioactive waste materials mainly disused sealed radioactive sources were characterised and stored in a storage facility at the GAEC premises
Draft regulation on management of radioactive waste was developed with assistance from the IAEA/AFRA Project RAF 4/015 in 2003
The Regulation addressed only predisposal issues
The regulation defined the responsibilities of waste generator, NRWMC and Regulatory Authority (RPB)

7. Radioactive Waste Management - Disposal
With increase in the quantity of disused sources being collected, the long half-life of some of the radionuclides, sources being historic and legacy waste, storage was considered an unsustainable option for management of the disused sealed radioactive sources (DSRS)
Hence the need for a disposal facility.
Considering the waste volumes, there is the need for:
- small volume repository
- safe technology with
- economically viable concept
In 2007 the Ghana expressed interest in exploiting the Borehole Disposal Concept for disposal of the disused sealed sources developed in South Africa under the IAEA Technical Cooperation Project

8. Strengthening Regulatory framework- (1/2)
The Nuclear Regulatory Authority Act 895 (2015) was passed by the Parliament of Ghana.
The Nuclear Regulatory Authority Act strengthen the regulatory functions and addressed radioactive waste management issues which were not covered in the LI 1559.
The law specifies the key functions and activities that are very important for effective regulatory system, including notification authorization, inspection and enforcement as well as development of regulations and guidance documents
In January 2016, the Nuclear Regulatory Authority (NRA) was established as the statutory regulatory authority in Ghana per provisions of Act 895.
The establishment of the Nuclear Regulatory Authority decoupled the Radiation Protection Board from Ghana Atomic Energy Commission

9. Strengthening Regulatory framework- (2/2)
Develop National Radioactive Waste Management Policy and Strategy – draft in 2015 (INT9176)
Revise and update the National Radioactive Waste Management regulation to include regulation on radioactive waste disposal – draft in 2016 (INT9176)
Harmonization of the Nuclear Regulatory Act,895 with the National Radioactive Waste Management Regulation
The Republic of Ghana acceded to the Joint Convention in May 2011 and participated in her first peer-review meeting in May 2012

10. Radioactive Waste Management- Facility
The Centralized Waste Management facility was upgraded in 2011.
The Waste Processing facility has an
office and laboratory spaces
operational areas for characterization and conditioning of the disused sources
The Centralised storage facility has
an area for receipt of the waste,
Decay and low activity storage unit and
a high activity storage unit.
Has physical protection systems

11. Implementation of the Borehole Disposal System- Siting
With assistance from Geological Survey Dept, a site within the GAEC premises was selected for implementation of the Borehole Disposal System (BDS).
Ghana Atomic Energy Commission premises at Kwabenya,
GAEC is located North-West of University of Ghana. It is about 24 km from the Central Accra

12. Implementation of the Borehole Disposal System- Geology
The crystalline bedrock that underlain the site is part of the West African shield or craton which has remained stable
The bedrocks are differently named as the Dahomenyan and the Togo structural units
The Dahomeyan unit is the major bedrock and composed mainly of schists with variable amounts of quartz, chlorite or biotite.
The Togo is characterized by quartzites and phyllitic rocks

13. Implementation of the Borehole Disposal System- Site Characterization I
Geophysical investigation (seismic refraction and electrical resistivity) carried out on the site indicate that the bedrock has high compressional and shear velocities.
The bedrock is located at a depth of 23.3 m has a high electrical resistivity of ohm-metre, which suggests that the bedrock is probably gneissic rock
This is overlain by a weathered material with electrical resistivities varying between ohm-metres.
The topsoil which consists basically of lateritic materials is associated with electrical resistivity of 1467 ohm-metres
Two points were earmarked to drill boreholes (BH1 and BH2) to facilitate site characterization

14. Implementation of the Borehole Disposal System- Site Characterization II
Two exploratory boreholes ( 150m) drilled for site characterization
Hydrochemical Data –Groundwater sampling pH
Major Cation
Major Anion
Isotopic Composition( O18 H2)
Hydrogeological Data
Hydraulic properties -(transmissivity, hydraulic conductivity, hydraulic gradient, storativity)
Geological Data
Nature and Rock distribution
Fractures and faults
Mineralogy

15. Site Characterization-Geologic Log
Boreh ole ID
Laterit e
Clay
Quartzite
Phyllite
Mixed materials (gneissic & others)
Schist
Fracture
Water
Strike
BH 01
0-4m
4-6m
6-12m
13-37m
38-50m
12-13m
37-38m
50-122m m
33-36m
47-55m
89-108m m
50-51m
94-95m
99-102m
BH 02
0-2m
2-4m
4-9m
19-52m
9-19m
52-110m m
31-41m
47-74m
99-105m
62-63m m

16. Mineralogical Composition- Thin section description of Borehole samples
Sample ID
Description BH
oxidized (local only) to moderately fresh granite BH
moderately fresh granite/granodiorite with pyrite BH
moderately fresh granite BH
schist, granite/gneiss; some pyrite BH
moderately fresh granite/granodiorite BH
moderately fresh granite/granodiorite; some schist/gneiss fragments
1 large bag
schist, green with a sulphide grain (pyrite)

17. Implementation of the Borehole Disposal System- Hydrogeology
Drawdown (Pumping) and test The Discrete Sector Test (Lugeon/Packer Tests) were used to estimate the hydraulic characteristics of rock mass
Borehole ID
Hydraulic head (H)
Pressure head (hp)
Hydraulic gradient (l)
Specific capacity (S.C.)
Transmissivity (T)
Hydraulic conductivity (K)
BH01
58.24 m m
Bet BH01 & BH02
0.820 m3/d/m
0.64 m2/d
1.23e-2 m/d
BH02
56.42 m m
0.034
0.432 m3/d/m
0.51 m2/d
1.11e-2 m/d

18. Implementation of the Borehole Disposal System-Hydrogeological Description of the BDS site
3 hydrogeological zones exist at the site;
Upper active zone of highly weathered and fractured rock. The zone extends from top to a depth of about 20m.
Second zone comprised of intact bedrock with discrete transmissive fracture zones of several metres thickness, of several interconnected fractures localised into zones. This zone extends down to 60m
The third unit is intact bedrock with low frequency of flowing fractures. possible fracture horizons exist at depths of m (inflow in lowermost 10m of BH2) and m in BH1 (water strike).
Hydrogeological Description of the BDS site

19. Implementation of the Borehole Disposal System-Groundwater chemistry
Parameter Unit Minimum Maximum  
Temp °C  
pH  
El. Cond. μS/cm  
TDS mg/L  
Ca mg/L  
Mg mg/L  
Na mg/L  
K mg/L  
Cl mg/L  
HCO3 mg/L  
SO mg/L  
NO mg/L
6 Groundwater sampling rounds
June & Dec 2013,
May 2014
November 2016
April & Nov 2017
A total of 60 groundwater samples were analysed

20. General Disposal Borehole Design
Deflecting Plate
Borehole Plug
Casing Grout
Casing Backfill
Disposed Waste Packages
14.2m
150 m
Host Rock
Borehole Backfill
Water Table (3-5m)
Centralisers
Disposal Depth Calculations
Layer on top of each container= 750mm
13 of such layers x 750mm = 9750mm
2 X 603mm Disp. Containers= 1206mm
3 X 375mm Disp. Containers= 1125mm
8 X 199mm Disp. Containers= 1592mm
Thickness of plug = 500mm
Total Depth of closure zone= 14173mm
= 14.2m
Depth of entire borehole= 135m m
= 149.5m

21. Conclusion-Ongoing Tasks
Efforts are being made to develop a comprehensive regulatory and radioactive waste management infrastructure in Ghana
The following reports have been developed and are being reviewed by IAEA experts;
Site Description report
Post Closure Safety Assessment report
Engineering Design of the Borehole Disposal System
Safety Case and environmental impact assessment reports have been drafted.
All the above reports when finalized will be submitted to the Nuclear Regulatory Authority for review and approval.
Acknowledgement: Ghana is grateful to the IAEA for assistance through the IAEA TC Project and other Project in the implementation of the Borehole Disposal System

22. Thanks for Your Attention