CAPE TOWN - Calls to decommission the Koeberg Nuclear Power Station have grown stronger, following an airborne contamination incident that resulted in several staff members being sent for tests to determine whether and how much radioactive isotope I-131 was absorbed into their bodies.
In a statement issued to stakeholders on Friday, Eskom said on October 28 at around 3pm, the ventilation system for the Koeberg Security Central Alarm Station (CAS) was tested, using the radioactive isotope I-131 as a tracer to represent the type of contaminant that needs to be filtered in the unlikely event of an accident at Koeberg.
“The CAS is located in an on-site building adjacent to the plant, and the ventilation system is tested every 18 months.
“During and following the test, airborne samples were taken at various locations to ensure that the required monitoring is performed in case of leaks or discharges from the system. The analysis and processing of the results became available.. on October 29. The results for the CAS control room was at a level that required the area be declared an airborne contamination zone. This was confirmed by a follow-up sample, which resulted in a decision to evacuate personnel from the CAS, and activate the alternative security control room,” Eskom said.
The tests identified the presence of I-131 in some of the staff, with the highest reading indicating “a committed dose of approximately 25% of the applicable regulatory limit”.
“Follow-up tests are used to further refine the dose assessment and will be completed over a two-week period. The preliminary committed dose based on initial readings is that the exposure in this incident is equivalent to what an individual would be exposed to during a long distance international flight. The regulatory limit for non-radiation workers – which the affected personnel are – was not exceeded.”
The cause of the elevated airborne contamination is being investigated, Eskom said.
While the parastatal did not respond to questions on Sunday, the Koeberg Alert Alliance (KAA) said no standard test procedure includes evacuating all staff from the security nerve centre of a nuclear plant and this showed there was “something significantly wrong”.
The group added that the incident is likely to be a result of a combination of three factors.
“Firstly, Koeberg was built starting in 1974 based on a 1960’s design. Modern designs would have a very different ventilation configuration and filtration test procedure. Secondly, Koeberg is in a harsh marine environment with the base of the containment domes 10m below sea level,” the KAA said.
“Thirdly, and most worrying, are questions around the competency of Eskom in terms of plant maintenance, and the ability of the company to retain skilled staff. With about half of Eskom’s capacity offline, there is undeniably a widespread problem within the company. Incidents such as one of the Medupi generators exploding due to a shoddy safety culture only adds to the concern. The COO of Eskom announcing that he had discovered a ‘horrifying’ exodus of skilled staff from Koeberg specifically is yet another warning sign of problems to come.”
The Southern African Faith Communities’ Environment Institute (SAFCEI) said the plant needed to be decommissioned.
SAFCEI’s Executive Director Francesca de Gasparis said: “Yet another piece of bad news from Koeberg. The general manager has been removed from office, unit 1 has been more down than up, we see Koeberg not providing this reliable, affordable or necessary energy to South Africa. The best thing to do with Koeberg would be to decommission it (and) invest in renewable energy. We don't need Koeberg in the future, it’s too risky.
“What renewable energy needs is batteries not nuclear energy, what we need is technology to store energy and we need to be able to use energy in different ways.”
Cape Times