SAFARI-1 research reactor

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SAFARI-1 is a 20 Megawatt tank-in-pool type nuclear research reactor, owned and operated by
the South African Nuclear Energy Corporation (Necsa) and it is located at Pelindaba, 30 km west
of Pretoria. SAFARI-1 is an acronym for South Africa Fundamental Atomic Research Installation
and is South Africa’s only nuclear research reactor.

Since it’s commissioning on 18th March 1965, SAFARI-1 has achieved many outstanding
successes and is currently engaged in a number of activities which are not only fascinating, but
also of great benefit to mankind. SAFARI-1 provides products and services both locally and
internationally to various industrial and institutional sectors, proving that nuclear technology does
indeed offer many beneficial applications.

In 1998 SAFARI-1 was awarded the prestigious ISO 9001 certificate for compliance to
international quality standards. At the time it was the second nuclear reactor in the world to
receive this award. The ISO 9001 accreditation recognizes the ability of SAFARI -1 to operate
within the international standards of design and production in providing quality products and
services to industry and community.

SAFARI-1 has subsequently also received the ISO 14001 Environmental Management (2003)
and OHSAS 18001 Occupational Health and Safety Management System (2011) certification.
SAFARI-1 utilises an overall Integrated Management System which not only encompasses
environmental controls but also includes operational safety, product quality radiological and
conventional safety and security systems which ensure that a good safety culture is established.


Some of the most spectacular advances in medicine in recent years have been in the fields of
imaging and scanning using selective medical isotopes. The development of these techniques
enables doctors to make precise and accurate diagnoses without – in many cases the need for
exploratory surgery. Isotopes are used in various chemical forms in a large number of dynamic
and static diagnostic studies which include imaging of the heart, brain, thyroid, liver, lungs,
kidneys and bone.

Necsa is by far Africa’s largest producer of a range of medical isotopes that are used for
diagnostic purposes and therapeutic treatment of cancer and many millions of people have
received the benefits of medical isotopes originating from SAFARI-1. Patients are treated
annually in South Africa and internationally with typical radioisotopes of which the targets
material is irradiated within SAFARI-1 for the isotope production facility of NTP Radioisotope
SOC Ltd.


Molybdenum-99 (99Mo) , the radioisotope used extensively as a raw material for technetium-99m
(the most important diagnostic nuclear medicine isotope), originally had to be imported into South
Africa on a weekly basis. Since 1993, with its unique ability to manage virtually the entire nuclear
production cycle, Necsa has become the sole local and an important international supplier of
99Mo. The nuclear production cycle, which is initiated with the enriched uranium, includes a fuel
fabrication plant for the manufacture of 99Mo target plates and the assembly of fuel for SAFARI-
1, the SAFARI-1 nuclear research reactor itself, a modern hot cell complex for 99Mo extraction,
and an isotope production centre (NTP Radioisotopes SOC Ltd) where the radioisotopes are
manufactured and packaged.

Since Necsa initiated local production of 99Mo in SAFARI-1, it has become one of the four largest
producers of the isotopes in the world.

Currently, Necsa via NTP has approval for the export of isotope products to a large number of
countries worldwide.

In the USA alone, several tens of thousands of diagnostic procedures using nuclear
radioisotopes are performed daily. Because 99Mo is radioactive and loose half of its activity every
66 hours, regular supply within extremely tight delivery schedules are essential.

Necsa has furthermore been able to assist in averting international nuclear medicine crises on
various occasions, when supply limitations threatened to paralyse the industry. Necsa has been
able to selectively place a large portion of the world demand for 99Mo into the market at extremely
short notice.


Silicon semiconductors (e.g. microchips) are used in electronic equipment which play an
important role in our lives today. Small quantities of phosphorus are required in high-purity silicon
crystal to provide the desired electrical properties. Traditionally, phosphorus is introduced into the
crystal structure chemically, but because the distribution is not always homogeneous, high
rejection rates and premature failure of electronic equipment can be experienced.

Phosphorus can also be produced in a crystal through a nuclear reaction between neutrons and
silicon atoms. Necsa has developed technology to irradiate silicon crystals at its SAFARI-1
nuclear research reactor. This method ensures homogeneous distribution of phosphorus and
obviates the quality problems associated with the chemical method. The technique was refined in
cooperation with some of Japan’s and Europe’s largest silicon manufacturers.


Although much of the utilasation of SAFARI-1 is focused on commercialisation, which includes
the activities highlighted above, the provision of support services such as neutron radiography,
neutron diffraction and neutron activation analysis providing strong industrial and academic links,
all receive a high profile in the day-to-day operations of the reactor.

The impeccably safe operational history of SAFARI-1 is undoubtedly due to the extensive
infrastructure available at Pelindaba to support SAFARI-1 in terms of required services. In
addition to the normal utilities (water, electricity, etc), a fuel production plant, modern hot-cell
facilities, an isotope production centre and radioactive waste handling capabilities (including a
disposal site) are available. A theoretical reactor physics group, conventional and radiological
safety and licensing support, as well as extensive electronic and mechanical design and
manufacturing capabilities, have enabled SAFARI-1 to be ranked as one of the top nuclear
research reactors in the world.

A comprehensive preventive maintenance programme and a strategy for the continuous
upgrading of plant equipment will ensure that SAFARI-1 will continue to operate safely well into
the future – maintaining a nuclear heritage of which we all, as South Africans, can be proud!


The Necsa Group, through NTP and with the SAFARI-1 research reactor playing a key role,
continued to be a reliable, leading supplier of radiochemicals to the global healthcare market.
NTP remained a leading supplier in the world with the ability to produce 99Mo at industrial scale
using a process entirely based on LEU (Low Enriched Uranium). The SAFARI-1 research reactor
operational availability average more than 300 days per annum at an average reactor power of
20 MW, which makes it one of the highest utilised reactors in the world. This achievement is the
result of a closely managed and effective maintenance programme, and the implementation of a
reactor ageing management programme.

A recent safety re-assessment conducted on the SAFARI-1 research reactor and its operational
systems, in response to a NNR directive, confirmed the fundamental safety and integrity of the
reactor and its operations. These safety re-assessments have been carried out on all major
research reactors worldwide subsequent to the events at the Fukushima Daiichi nuclear plant in

Copyright Necsa 2012