No plans to restore abandoned Protvino project 20 May 2021

Underground particle physics research began in Russia in the Soviet era when, 55 years ago, a scientific town to support the world's largest proton accelerator at the time was built in the Serpukhov forests near the Protva River. The town became a site for an ACS accelerating storage complex, a collider facility for a beam energy of 3 teraelectron volts. The accelerator storage complex, with a length of 1.5km, was built over a short time frame and completed by 1967 to celebrate the 50th anniversary of the October Revolution. In 1972, its status as the world’s largest accelerator passed to the Fermi National Accelerator Laboratory (Fermilab) near Chicago in the USA.

Fig 1. The 21km particle physics collider excavated at Protvino

The first stage of the Protvino installation, commissioned in 1967, had an accelerator power of 70 GeV (109 electronvolt). Several years later, design began for a new accelerator to be a proton-proton collider with an energy of 3 TeV (1012 eV) under the name of U-70. The ASC was to be the booster stage for the new collider.

The decision to build the particle physics research complex in the Protvino area was taken due to its stable geological conditions with the deposits laid by as the bottom of the ancient sea suitable for the excavation of large underground infrastructure and for its low risk from seismic activity. For this purpose, a 5m diameter x 21km long tunnel ring, with the size exceeding the ring line of the Moscow Metro, was built. Construction using open face mining methods through stable, dry conditions and up to 60m deep from 26 access shafts began in 1983 and most of these works were completed by 1994. In addition to the main tunnel, a technical tunnel was built being intended for the placement of cables and pipes, which were supposed to supply energy to the ASC. Further straight sections of the tunnel were built for placing of technological systems of the future use of the ASC. These were extended halls with a diameter of up to 9m and a length of about 800m.

As the tunnel ring excavation progressed the headings were supported with cast-iron tubings with and external concrete cover and lined on the inner surface with 8mm thick sheet steel. A cast concrete invert was the foundation of rail services in the headings. Most of the excavations works were conducted by the Moscow-based Protontonnelstroy enterprise, the company which was previously involved in building the Moscow Metro. For several years, the construction was carried out at a sluggish pace, with only 1.5km of tunnel built during the period of 1983-1987.

Abandoned underground infrastructure

In 1987, the Soviet Government decided to speed up the works by importing and using two modern TBMs. Both TBMs purchased from Lovat of Canada became for the first imports of tunnelling equipment to the Soviet Union since the last in 1935.

By the mid-1990s, the main tunnel was completed, after which installation of equipment began. Prior to the launch of the first stage of the project, about 70% of the required research equipment was manufactured. For the second stage, the design works were completed and dozens of superconducting magnets were being manufactured and prepared for installation.

In 1994 builders completed building of the last and most difficult section of the 21km tunnel due to groundwater ingress issues. This became the 2.7 km long underground link connecting the U-70 and the ASC. Still, due to the lack of funds, further construction works were suspended. As of 1994, only a part of the accelerating structure for the first stage of the ASC and several dozen magnets of the superconducting structure were produced. The concept of the project required production of 2,500 of such magnets, each weighing about 10 tonnes.

A research facility for cancer cure research is one suggestion for reusing the underground infrastructure

Since 1994, the tunnel has been mothballed and was finally closed in 1998. There are currently no plans to finish its building since a more modern Large Hadron Collider has been operating in Swiss Geneva since 2008 and of which Russia is a contributor and research partner. Technical maintenance of the built structures however is a constant need, as the destruction of the underground facilities may lead to serious consequences and environmental damage.

At present some parts of the tunnel ring are flooded with groundwater, which has to be regularly pumped out. Current pumping and other technical maintenance requirements are estimated at about RUB 80 million (US$1.08 million) annually, most of which is provided from the Russian Federal budget.

Currently the Federal Government, together with the domestic physics community, is considering several options for the further use of the facilities at Protvino. One option involves the installation of mega-science units, while others include creating an underground farming installation or a museum. So far, most of these proposals have been rejected by the state as their implementation will be associated with high costs that will have to be covered from the Federal budget.

Mikhail Kovalchuk, a former President of the National Research Center Kurchatov Institute

Perhaps, the most likely proposal may involve building of a small particle accelerator that will be used for the design of a new generation of anti-cancer drugs. The idea was put forward by Mikhail Kovalchuk, a former President of the National Research Center Kurchatov Institute. If everything goes ahead, the supply of the tunnel with energy will be carried through the direct cable from the near by Smolensk nuclear power plant. In regard to the U-70 accelerator at Protvino, it currently remains in operation and has brought some fundamental results and several scientific discoveries including the so-called Serpukhov effect in recent years. Currently, no major construction works on the tunnel are underway, while most of the equipment for the collider remains in storage.

The demise of the Protvino large ring collider project in Russia in the 1990s was mirrored by cancellation and closed down in 1993 of the Superconducting Super Collider (SSC) underground laboratory in Texas in the USA. After spending US$2 billion and completing 22.5km and 17 shafts of the 97km x 4m-5m i.d. collider ring and its 52 shafts, rising costs, including for the production of the superconducting accelerating magnets; poor management by physicists and Department of Energy officials; the collapse of the Soviet Union and the ending of the Cold War; as well as development of CERN in Europe as the shared multi-national nuclear particle physics research facility, convinced the US Congress to discontinue funding the SSC laboratory in Texas. President Clinton signed its cancellation and end of all works in October 1993.