Angra-3 PWR Nuclear, Brazil

The 1,224MWe Angra-3 PWR nuclear reactor project is on again. The Brazilian government has announced plans to complete the reactor, which will work alongside the other two at Angra, which is between Rio de Janeiro and Sao Paulo. Angra 3 has cost $750m already and is estimated to cost another $1,835m to complete (40% in Euros and 60% in Brazilian currency), to be paid back over 40 years.

Angra-3 was designed to be a twin of the four-loop Angra-2, but was halted in the mid 1980s after shortages of finance. Around 70% of equipment is already on site, but construction has still not begun.

Eletrobras (70% owned by the Brazilian government and the main shareholder in the Brazilian nuclear utility Eletronuclear) has been looking for the necessary $1.8bn from a private partner to complete the project, but there has also been some interest from the Russian government.

Angra-1 and Angra-2 are now producing 630 and 1,270MWe (net). Angra-1 had to be shut down early in its life after problems with its steam supply system.

The World Nuclear Association reports it had a load factor of only 25% over the first 15 years of operation, but has greatly improved since then. The Brazilian government has announced plans to build another four 1,000MWe reactors from 2015, with a total of up to 8GWe by 2030.

GOVERNMENT ANNOUNCES GO-AHEAD FOR ANGRA-3

Brazil's electricity consumption has been growing strongly over the last 15 years. Hydroelectric provides over 80% of the total (although droughts have caused power shortages) with nuclear at less than 5%. Around 40% of the total is produced by Eletrobras.

The turnkey Angra-1 was built by Westinghouse, starting in 1971 and coming on stream in 1982. In 1976 the Brazilian government signed an agreement with West Germany for eight 1,300MWe nuclear units, to be built by 1990. Siemens-KWU built the first two plants, with a technology transfer agreement aiming to build the rest with 90% Brazilian content.

The projects were however suspended. Eletrobras took over responsibility for building Angra-2 and Angra-3, and in 1995 started construction at Angra-2 again. Eletrobra and German banks provided $1.3bn of new investment, and Angra-2 was completed in 2000.

Angra-3 is a PWR, so a second-generation reactor using high-pressure superheated water as coolant and neutron moderator. PWRs are the world's most-used type of reactor. The chain reaction in the nuclear fuel heats water in the primary to over 300ºC, with the hot water pumped into a steam generator (heat exchanger) to boil water in the secondary coolant loop. This drives a steam turbine. The primary and secondary coolant loops keep radioactive water in the first loop separate from that used to drive the steam generator.

SERVICED BY FRAMATOME

Framatome ANP performed service work at Angra 2 in March 2002, during the first of the annual refueling outages. Work was done on the reactor floor, fuel assemblies, valves, pumps and pump motors. Framatome also inspected the emergency diesel generating units, electrical and I&C systems, HVAC systems, and reactor coolant pumps.

The inspection work by over 1,000 engineers was done in less than 30 days with Eletrobràs Termonuclear (Eletronuclear) and German and Brazilian subcontractors.

OVER 5% OF WORLD’S TOTAL URANIUM DEPOSITS

Brazil has over 5% of the total world uranium deposits, with about 230,000t although only one mine is now working, INB's Lagoa Real Unit. The uranium is converted and enriched abroad and then used in Brazil but some of Angra's fuel is now produced by Brazilian centrifuges.

In 2006, Brazil opened a new centrifuge facility at the Resende nuclear plant, claimed to be 25 times more efficient than French and US facilities. The government said it hoped to meet all its nuclear energy needs within a decade. The centrifuges were subject of some discussions with the International Atomic Energy Agency, with safeguards to ensure there will be no links to weapons production.