Russia speeds up manufacture of icebreaker reactor

26 April 2017

Russia's Zio-Podolsk has completed "one of the most complex" manufacturing operations on the reactor head of the Sibir nuclear-powered icebreaker, using a new tool that reduces the time required to bore holes in the structure from 150 days to 36 days. Sibir is the second of three vessels of the Project 22220 - featuring RITM-200 (Rhythmn-200) reactors - that will be able to break through ice 3 meters thick as they escort vessels across the Arctic Ocean. The others are Arktika and Ural.

Reactor head for Sibir icebreaker - 460 (Atomenergomash)
Reactor head for Sibir icebreaker (Image: Atomenergomash)

The first nuclear icebreaker to be fully built in modern-day Russia, Arktika was launched at the Baltic Shipyard in Saint Petersburg in June last year. The Atomflot state unitary enterprise said in February this year it expects Arktika to enter first operational service in mid-2019. Sibir and Ural are scheduled for delivery in 2020 and in 2021, respectively.

Zio-Podolsk, a subsidiary of Russian state nuclear corporation Rosatom, said on 24 April that it had used a new tool to bore holes into Sibir's reactor body. The tool is "a special perforated drill equipped with replaceable cartridges with carbide-tipped cutting inserts and a pilot cutting part made of high-speed steel", it said.

The company noted that the RITM-200 reactor design's "energy-efficient integrated layout", which enables the placement of the main equipment directly inside the steam generating unit's casing, means the structure is half the weight, one-and-a-half times more compact and 25 MWe more powerful than reactor systems for the icebreaker fleet of the KLT series. This provides "improved technical characteristics" for icebreakers in terms of the speed at which they can break through ice, it said. A RITM-200 reactor has an operating life of 40 years, with refuelling required once every seven years, it added.

The Sputnik news agency reported on 29 March that Arktika is to be handed over to Rosatom in May 2019. Citing Vasilly Osmakov, Russia's deputy trade and industry minister, the report said the schedule for Arktika had changed because of the "first use of innovative equipment", as well as Western economic sanctions, which Osmakov said have been "fully resolved".

In January 2013, Rosatom called for bids to build two more of the Project 22220 icebreakers, and in May 2104 a contract was signed with United Shipbuilding Corporation (USC) for the vessels to be built at the same shipyard. In August of the same year Russian regulator Rostechnadzor licensed Baltic Shipyard to install the RITM-200 reactor units from OKBM Afrikantov for the pilot model. The keel of Arktika was laid in November 2013, and that of Sibir in May 2015.

The icebreaker Lenin was the world's first nuclear-powered surface vessel (20,000 dwt) and remained in service for 30 years (1959-89), though new reactors were fitted in 1970. It led to a series of larger icebreakers, the six 23,500 dwt Arktika-class vessels, launched from 1975. These have two 171 MWt OK-900 reactors delivering 54 MW at the propellers and are used in deep Arctic waters.

The Arktika was the first surface vessel to reach the North Pole, in 1977. The seventh and largest Arktika class icebreaker - 50 Let Pobedy (50 Years of Victory) entered service in 2007. It is 25,800 dwt, 160m long and 20m wide, and is designed to break through ice up to 2.8m thick.

For use in shallow waters, such as estuaries and rivers, two shallow-draught Taymyr-class icebreakers of 18,260 dwt with one reactor delivering 35 MW were built in Finland and then fitted with their nuclear steam supply system in Russia. They are built to conform with international safety standards for nuclear vessels and were launched from 1989.

Larger third-generation 'universal' LK-60 icebreakers, of which Arktika is the first, are being built as dual-draught (8.55 or 10.5m) wide-beam (34m) ships of 25,450 dwt or 33,540 dwt with ballast, able to handle 3 metres of ice.

In August 2012, USC won the contract for the first new-generation LK-60 icebreaker powered by two RITM-200 reactors of 175 MWt each, delivering 60 MW at the propellers via twin turbine-generators and three motors. They would be built by subsidiary Baltic Shipyard.

A more powerful LC-110 icebreaker of 110 MW net and 55,600 dwt is planned to be capable of breaking through ice up to 4.5 m thick. The first vessel will be Leader.

Researched and written
by World Nuclear News