22 November 2017

Driving into danger with the blue lights flashing


The PSI radiation protection service is responsible for missions not only at the Institute, but throughout the canton of Aargau. Four times a year the unit practises for an emergency.

The explosion in the laboratory blew out the window and swept blue gloves as well as a container marked with the radiation warning symbol outside onto the asphalt. Men wearing yellow and black fire protection gear and beige helmets hop out of the red personnel carrier of the PSI radiation protection service, pull on their respirators, roll out yellow barrier tape, swarm about with measuring devices, and give instructions until it is clear who needs to do what – the unavoidable confusion in the first seconds of an emergency exercise.

Inside the laboratory, the men find their colleague Can Yesiltepe, who plays the part of an injured person. They transport him outside in a canvas carrier and cut open his yellow overalls – the initial rough decontamination. Guys, you must be kidding! calls Mathias Heusser, who has been appointed officer-in-charge by radiation protection service chief Gabriel Frei, as Yesiltepe lies on the canvas in his underpants and undershirt. Only now do they shield the radiation protection service member from curious onlookers with a tarpaulin.

A few minutes later, Gabriel Frei ends the exercise and orders the 14 men into formation in a military semicircle. Frei, with round glasses and an alert look, points to the windows of a building next to the exercise area of the plant fire brigade. Today, not one minute would have gone by before someone with a mobile phone shot a photo. And suddenly the injured person is on an online portal in his underpants. Aside from that, Frei is pleased. Within a few minutes, the men of the radiation protection service located the radiation sources in the shrubbery as well as behind the laboratory wall and set up a hazard zone around them.

Militia troop with technical expertise

The PSI radiation protection service is a unit of the plant fire brigade at PSI. The regular firefighting team would go into action in case of an emergency on the PSI campus as well as at the neighbouring ZWILAG, the interim storage facility for radioactive waste where, among other things, fuel rods from nuclear power plants are stored. In addition, it supports the fire brigades of neighbouring Würenlingen and Geissberg, since during the day these are only slowly mobilised.

The radiation protection service, on the other hand, is responsible for the entire canton of Aargau since 2006. Prior to that, the canton's 11 fire brigade bases had the primary responsibility, but hardly any experience – in stark contrast to PSI, where radioactive materials are regularly handled in the laboratories and used in research. At PSI it is ensured at all times that the necessary expertise is at hand, says Thomas Aldrian of the Aargau Department of Health and Social Services, explaining the decision.
At PSI it is ensured at all times that the necessary expertise is at hand.

Thomas Aldrian, Department of Health and Social Services, canton Aargau
The 22-person radiation protection service, like the PSI plant fire brigade as a whole, is a militia organisation, yet many of its members also deal with radioactivity as part of their jobs. Like seven other members of the PSI fire brigade, radiation protection service chief Gabriel Frei works at ZWILAG, where he is about to take over the management of radiation protection. Frei is a skilled nuclear power technician, worked for a long time as an operator in Beznau, and received further expert-level training in the subject of radiation protection. Can Yesiltepe, the extra in the exercise, works as a radiation protection specialist in the dismantling of a research reactor at PSI. Juggling work in the radiation protection service and the Institute is not easy, according to Frei. Among scientists, it's often: I don't have time for that. Eighty percent of his troop consists of technicians with occupational training; only a few researchers join in. Service in the radiation protection service is especially time-consuming for PSI staff. Besides the fire brigade's two-day basic course, they have to complete another week-long course in which they learn how to operate the radiation measurement devices and to set up a hazard zone.

For the second drill, on the street section of the exercise area, Gabriel Frei staged an accident on highway A1 with two decommissioned PSI vehicles. A van with suspicious cargo rammed into a passenger car. In the collision a package marked with a radiation warning symbol was catapulted onto the street. Not an unrealistic scenario, according to Frei. This is how clinics transport, for example, radioactive material for radiation therapies.

Here, in contrast to the first scenario, which was set on the PSI campus, the radiation protection service needs to cooperate with the local – and unfamiliar – fire brigade. Gabriel Frei plays the impatient commandant. He greets radiation protection service officer André Burkhard. I'd like to get my two men away from the accident site, and the police officer in charge wants the street cleared again as fast as possible. One minute of roadblock on the A1, Frei explains, backs up traffic for one kilometre.

Keeping the phone within earshot overnight

The radiation protection service members, however, are not thrown off. They first set up a hazard zone around the accident site and then meticulously scan the local firefighters with their measuring devices before allowing them to leave the scene. Yet Gabriel Frei, as commanding officer, keeps the pressure on. The NAZ wants an initial situation analysis, he calls out to radiation officer Burkhard. In the canton of Aargau the national alarm headquarters NAZ, which is responsible for such accidents on the national level, has sole authority, together with cantonal officials, over the removal of radioactive material. The cantonal PSI radiation protection service is only permitted to identify it and set up a hazard zone around it.

After the exercise – one of four per year – the radiation protection service reassembles in the fire service depot. The men stow their protective suits and gear in the lockers or chat with each other, with the suspenders of their fire-protection trousers over sweaty T-shirts. At the entrance to the depot hangs the plant layout of PSI, with a list of important mobile phone numbers. The PSI radiation protection service has never yet had a serious emergency, Gabriel Frei recalls, except for a false alarm a few years ago. Still, every member of the radiation protection service spends the night with his mobile phone within earshot. If headquarters calls, everyone who can manage to get himself to the depot needs to do so.

Instead of the usual beer after a fire brigade exercise, the radiation protectors share a box of Kägi wafers supplied by Klaus Hermle, acting commandant of the PSI fire brigade. It is shortly after four; some head home, others back to work. Can Yesiltepe, who played the injured man in the first exercise, has already pulled on his blue technician's overalls and hops on his bicycle and rides away.

Text: Joel Bedetti

5232 — Das Magazin des Paul Scherrer Instituts03/2017

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