Workers inside Borexino, a detector in Italy that detects neutrinos as they interact with a hydrocarbon liquid. Credit: Roberto Caccuri/Contrasto/eyevine

Three officials from Italy’s National Institute for Nuclear Physics (INFN) will face trial for allegedly overlooking environmental safety regulations at the institute’s Gran Sasso underground laboratories, a world-leading physics facility near L’Aquila, in central Italy, that hosts neutrino and dark-matter experiments. The indictments are the culmination of a long history of concerns from local communities and authorities about the labs' safety.

Prosecutors in nearby Teramo have charged INFN president Fernando Ferroni, the laboratories’ director Stefano Ragazzi and the head of the lab’s environmental services Raffaele Adinolfi Falcone. According to the accusations, which were prompted by complaints from local environmental activists, they have failed to verify the correct functioning of systems that, in the event of a large spill, would keep toxic substances used in two experiments away from drinking-water sources. If found guilty, they face fines and sentences of up to four years in prison. The trial is set to begin on 13 September.

INFN president Fernando Ferroni.Credit: Tanio/Contrasto/eyevine

Ferroni and Ragazzi declined to comment. Adinolfi did not reply to Nature’s request for an interview, and neither did the prosecutors. Antonio Zoccoli, INFN’s vice-president, responded on behalf of the Institute, saying that if any risk at the facility exists, it is not the current management’s fault.

Chemical spillage

The Gran Sasso National Laboratories are the world’s largest underground physics facility. They were built in the 1980s next to a highway tunnel under the Gran Sasso massif, and currently host 16 experiments on neutrino physics, dark matter, astrophysics and particle physics. Problems at the lab began in the summer of 2002, when 50 litres of the hydrocarbon trimethylbenzene accidentally spilled from one of the lab’s experiments, Borexino, which looks for solar neutrinos. The substance, which can be toxic in high doses, was then detected in a nearby river.

As a result, Borexino was put on hold. Part of the lab was sealed by the Teramo court, and the Italian government ordered a renovation of the facility’s safety systems. The intervention cost more than €80 million (US$90 million), and was completed in 2006.

But environmental groups argued that the lab was still not complying with regulations enacted that year, which say that toxic substances must be kept at least 200 metres away from sources of drinking water. The lab halls are surrounded by the aquifer that feeds the local aqueduct and is the main source of water for the surrounding Abruzzo region.

In addition to Borexino’s 1,300 tonnes of trimethylbenzene, the labs host about 1,000 tonnes of petroleum-derived liquids stored in the large volume detector (LVD), which looks for neutrinos emitted by supernovae. “Those two tanks should have just been removed according to the law,” says Augusto De Sanctis, an environmental activist and president of the local non-profit organization Abruzzo Ornithological Station.

Tensions rose again at the end of 2016, after a lab technician accidentally spilled some solvent while doing maintenance on CUPID, another neutrino experiment. Another accident, this time unrelated to the lab’s activity, occurred in May 2017 and involved a chemical found in the paint used for renovating the highway tunnel. In both cases, tests performed by the local environmental protection agency found the substances in the aqueduct’s waters, although within safety thresholds.

Complaints filed

Still, those accidents prompted De Sanctis to file complaints to the local prosecutors, who appointed three experts for a thorough investigation into the lab and tunnel’s safety. The investigation found that the lab lacks proper isolation between the experimental areas and the aquifer — as required by Italian environmental regulations — as well as between the lab’s own drainage system and the aqueduct.

Without such insulation, the prosecutors argue, a serious accident involving toxic chemicals would threaten the health of the local population. The prosecutor also reaffirmed that Borexino and LVD should be at least 200 metres away from the aquifer. In addition to the three physicists, the court indicted managers of the companies operating the highway and the aqueduct.

“The work done between 2004 and 2006 to renovate the safety systems was validated by the government, and by the court itself that unsealed the lab,” Zoccoli says. “Now the prosecutor is saying that those works were not done properly, but it was not INFN’s responsibility to check them.” As for the 200-metre rule, he says it refers to surface springs rather than to aquifers such as Gran Sasso, where the source is in fact the whole mountain. And risks have to be assessed “rationally”, he says. “The two detectors are sealed in very robust steel tanks and are constantly monitored. There’s no such thing as zero risk, but here the risk is really low”.

De Sanctis disagrees, noting that the area is highly seismic, and that the possibility of a very strong earthquake causing an accident cannot be ruled out. In 2009, for example, L’Aquila and its surroundings were hit by a magnitude 6.3 earthquake that killed 309 people. The laboratories were not affected that time, but history shows that the area can be hit by even stronger earthquakes, such as the magnitude 6.7 one in 1703. “Thousands of people would remain without drinking water for years” in case of a large spill, he says. “Even if the probability is low, it is not a risk worth taking”.

Borexino and the LVD are close to the end of their scientific life, and INFN has started removing their tanks. Decommissioning is itself a potentially risky engineering project. It should be completed by the end of 2020, “but the exact timing will depend on when we get the necessary authorizations” says Zoccoli.

Local communities have also voiced concerns about a planned future experiment at Gran Sasso called Luna MV, a particle accelerator for studying nuclear fusion currently under construction. Like all high-energy accelerators, it would generate small amounts of radioactivity. “It poses no risk, and I am confident the authorization process will continue as planned,” says Zoccoli.

He adds that INFN is also evaluating a proposal for a dark-matter detector that would use materials similar to those used by Borexino and the LVD, but in much smaller quantities, which would not be covered by the same regulations. But he fears that the tension surrounding the trial may slow down progress for both projects. “We just hope that in the end the trial will help clarify things once and for all,” Zoccoli concludes.

De Sanctis wants the Italian government to find €170 million to renew all water conduits at the laboratory and the tunnel, as requested in January by the Abruzzo regional authorities. And he says that the INFN must remove those two experiments as soon as possible and plan the next ones differently. “I know Gran Sasso is a great place for doing physics,” he says, referring to how the mountain shields the labs from radiation that would interfere with the detectors. “But it has limitations, in particular because of water and earthquakes.”