HSZG goes "underground"

4 students in the “Energy and Environmental Engineering” degree programme (specialization: Radiation and Nuclear Energy Engineering) and the Master's degree programme in “Mechanical Engineering and Energy Technology” in the Faculty of Mechanical Engineering, along with three students from the “Ecology and Environmental Protection” degree programme in the Faculty of Natural and Environmental Sciences, took part in a two-day field trip/course / fieldwork.

We had to get up early, as we set off on December 21, 2016, at 4:45 a.m. in the university’s excursion minibus headed for the Morsleben Final Repository for Radioactive Waste (ERAM). After a 4-hour drive, we reached our first destination—the BfS Information Center in Morsleben. There, we received an introduction to the history of the salt mine, an overview of its use as a final repository for low- and intermediate-level radioactive waste, as well as the quantities stored there, and were briefed on the proposed decommissioning plan, which is currently undergoing the planning approval process under nuclear law. We were also briefed on the ongoing restructuring of the current operator, the Federal Office for Radiation Protection (BfS), into the Federal Corporation for Final Disposal (BGE mbH).

After receiving instructions on conduct underground, the mandatory safety check upon entering the final disposal facility, and putting on mine-appropriate protective clothing, oxygen self-rescuers, and a miner’s lamp, we descended underground accompanied by a female and a male DBE employee, with the hoist cage traveling at a speed of 4 m/s. This allowed us to experience firsthand what it looks like nearly 500 meters below the earth’s surface in a salt dome. Highlights of the tour through the mine complex in diesel vehicles included a visit to the surveying office, former underground salt mining chambers, and the nearly completed massive underground workshop.

After the wrap-up discussion and a tour of the exhibition at the Info Center, we continued on to the JH Braunschweig. As a small “cultural” highlight of the excursion, we visited the Braunschweig Christmas market that evening.

The next morning, we headed to the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig—Germany’s national metrology institute, essentially the highest-level state calibration institute in Germany. In the introductory lecture, we were given an overview of the history and tasks of the PTB, and the new basis for the International System of Units (SI), effective as of 2017, was explained. This was followed by a guided tour of the historical collection of power measurement instruments used in electrical engineering and a second tour of the laboratory building housing the Time Standards Research Group. We were introduced to the conventional cesiumCS1 and CS2, featuring a thermal atomic beam, as well as the modern cesium fountain clocks CSF1 and CSF2 with laser-cooled atoms, which are among the most accurate atomic clocks in the world. These atomic clocks provide the standards for time and frequency and form the basis for the national reference time scale UTC(PTB).

We had to hurry back to our university bus, as we were already half an hour behind schedule. On the way to Gesellschaft für Nuklear-Service mbH (GNS) in Gorleben, we were then only able to grab lunch “on the fly” at a well-known fast-food restaurant. At the GNS Information Building in Gorleben, Mr. Lutz Oelschläger welcomed us personally; who himself studied nuclear power plant engineering at the Zittau University of Applied Sciences starting in 1985 and, after holding several positions at GNS, has served as plant manager at the Gorleben interim storage facility since 2008. We toured the exhibition at the Info-Building, which featured exhibits on the interim storage of heat-generating, highly radioactive waste. A large cloud chamber was also in operation, allowing us to get a good visual impression of the naturally occurring radioactivity in the environment. After a short drive to the plant grounds and the customary security check, we were divided into two groups. One group at a time was able to learn about safety experiments for CASTOR containers in a video room, while the other group took a guided tour of the transport container storage facility, which houses precisely such containers.

After all the experiences of this second day of the field trip, “all that was left” was the trip home. Unfortunately, the weather and traffic weren’t on our side, so the last participants didn’t arrive back in Zittau until after a 6-hour minibus ride.

Quotes from the students’ field trip reports:

“Both Morsleben and Gorleben were impressive storage facilities, and the guidance we received at each location was good. Personally, I was most impressed by the Gorleben interim storage facility. The costs were reasonable given the scope of the trip, and the accommodations were very good. Despite the long drives, I would go on this field trip again in a heartbeat and can highly recommend it to everyone—even those who aren’t particularly enthusiastic about nuclear technology.”

“The tour of the mine was the highlight of the first day of the field trip and offered spectacular sights.”

“The part of the field trip when we were in Morsleben was awesome! Especially the ride underground. By the way, the salt tastes good….The PTB in Braunschweig was less interesting. The atomic clocks there were even better than the exhibition on electric meters.”

“What surprised me was the size of the mine and the strict regulations the operators must follow, since it’s not only a medium-level radioactive waste repository but is also operated in accordance with mining law. I took the following statement from our guides to heart: ‘What is not expressly permitted is prohibited.’”

“The field trip offered a varied and very interesting program. The highlights were the descent into the salt dome in Morsleben and the tour of the Castor containers in Gorleben. It is highly recommended and likely a once-in-a-lifetime opportunity to gain insights into the storage of radioactive materials.”

“All three tours were interesting; it was a good organization, and the guides were more than happy to answer any questions that came up. For me personally, the mine and the interim storage facility were the highlights.”