Mon. Oct 14th, 2019

SVMAKERS.ORG

Shenango Valley Makers

Is the World Ready for Floating Nuclear Power Stations?

The world’s first floating nuclear power plant (FNPP) docked at Pevek, Chukotka, in Russia’s remote Far East on 14 September. It completed a journey of some 9,000 kilometers from where it was constructed in a St. Petersburg shipyard. First, it was towed to the city of Murmansk, where its nuclear fuel was loaded, and from there took the North Sea Route to the other side of Russia’s Arctic coast.

The FNPP will replace an aging land-based nuclear plant and a brown coal-fired plant, reducing some 50,000 tons of CO2 emissions a year, according to Rosatom, the project’s creator and Russia’s state nuclear corporation. The reactor is slated to begin operations this December.

The co-generation plant, named the Akademik Lomonosov, consists of a non-motorized barge, two pressurized-water KLT-40S reactors similar to those powering Russian nuclear icebreakers, and two steam turbine plants.

The FNPP can generate up to 70 megawatts (MW) of electricity and 50 gigacalories of heat an hour. That is sufficient to power the electric grids of the resource-rich region—where some 50,000 people live and work—and also deliver steam heat to the supply lines of Pevek city. The plant will manage this second feat by using steam extracted from the turbines to heat its intermediate circuit water system, which circulates between the reactor units and the coastal facilities, from 70 to 130 degrees C.

Construction of the floating reactor began in 2007 and had to overcome a messy financial situation including the threat of bankruptcy in 2011. The venture is based on the small modular reactor (SMR) design: a type of nuclear fission reactor that is smaller than conventional reactors. Such reactors can be built from start to finish at a plant and then shipped—fully-assembled, tested, and ready to operate—to remote sites where normal construction would be difficult to manage.

Andrey Zolotkov, head of the Murmansk, Russia office of Bellona Foundation, an environmental organization based in Oslo, Norway, acknowledges the practicability of the SMR design. But he is one of many who questions its necessity in this particular case.

“The same plant could be built on the ground there (in Chukotka) without resorting to creating a floating structure,” says Zolotkov. “After all, the [nuclear power plant] presently in use was built on land there and has been operating for decades.”

The floating design has raised both environmental and safety concerns, given that the plant will operate in the pristine Arctic and must endure its harsh winters and choppy seas. Greenpeace has dubbed it a “floating Chernobyl,” and “a nuclear Titanic.”

Rosatom rejects such criticism, saying the plant meets safety standards put forth by Russia and the International Atomic Energy Agency. The company notes the same kind of reactors have been used in icebreakers and submarines for decades. And, Rosatom states on its website, the “FNPP will be moored and secured to a special pier,” and operate without the need for “motor or propeller functions.”

Coastal structures, dams, and breakwaters have also been built to protect the vessel against tsunamis and icebergs.

The plant employs a number of active and passive safety systems, including an electrically-driven automated system and a passive system that uses gravity to insert control rods into the reactor core to ensure the reactor remains at subcritical levels in emergencies. The reactors also use low enriched uranium in a concentration below 20 percent of Uranium-235. This makes the fuel unsuitable for producing nuclear weapons.

Given such safety measures, Rosatom says on its site that a peer-reviewed probabilistic safety assessment modeling of possible damage to the FNPP finds the chances of a serious accident happening at the FNPP “are less than one hundred thousandth of a percent.”

Zolotkov, who worked in various capacities—including radiation safety officer—for 35 years in Russia’s civilian nuclear fleet, also notes that there have been no serious incidents on such ships since 1975. “In the event of an accident in the FNPP, the consequences, I believe, would be localized within its structure, so the release of radioactive substances will be minimal,” he says.

The plant’s nuclear fuel has to be replaced every three years. The unloaded fuel is held in onboard storage pools, and later in dry containers also kept on board. Every 10 to 12 years during its 40-year life cycle (possibly extendable to 50 years), the FNPP will be towed to a special facility for maintenance.

After decommissioning, the plant will be towed to a deconstruction and recycling facility. Rosatom says on its site, “No spent nuclear fuel or radioactive waste is planned to be left in the Arctic—spent fuel will be taken to the special storage facilities in mainland Russia.” 

Rosatom has not disclosed the cost of the venture, calling it a pilot project. It is currently working on a next-generation version that will use two RITM-200M reactors, each rated at 50 MW. Improvement targets include a more compact design, longer periods between refueling, flexible load-following capabilities, and multipurpose uses that include water desalination and district heating.

Provided Rosatom receives sufficient orders, it says it aims to compete in price with plants based on fossil fuels and renewable energy.

The company, however, may face challenges other than marketing and operating its novel design. “These FNPPs will eventually carry spent nuclear fuel and are not yet recognized by international maritime law,” says Zolotkov. “So Rosatom may face problems obtaining permits and insurance when it comes to towing them along certain sea routes.”