Decommissioning

Companies mentioned in this week's brief include: NRC, VATESI, Areva, Korea Electric Power, NDA.

NRC approves alternative reactor vessel requirements

The Nuclear Regulatory Commission approved a final rule to provide alternate requirements for protection against pressurised thermal shock events in nuclear power plant reactor vessels.

Updated analysis methods allow pressurised-water reactor (PWR) licensees to better account for some effects of aging on their reactor vessels.

The rule increases the realism of calculations used to examine a PWR’s susceptibility to pressurised thermal shock (PTS), which can occur under some scenarios that rapidly cool the internal surface of the reactor vessel while the vessel is pressurised. The NRC explained in a statement: “This would subject the steel to substantial thermal stresses, which could lead to cracking and potential failure of the vessel.

The other type of US nuclear power plant design, a boiling water reactor, is not susceptible to PTS.

"The rule allows licensees of operating PWRs to voluntarily adopt a more realistic technical approach for determining the probability of vessel failure during a PTS event," explained the NRC.

This revised approach was derived using data from research on currently operating PWRs.

The data indicate the overall risk of PTS-induced vessel failure after 60 years of reactor operation is much lower than previously estimated.

If a licensee chooses to adopt the new approach, the rule would require PWR operators to perform detailed analyses of both reactor vessel surveillance data and the results of regular reactor vessel inspections.

If the analyses’ findings exceed certain limits, the operator must take steps to either limit the reactor vessel’s exposure to neutron radiation (which can make the vessel brittle) or determine how the reactor’s systems can be modified to prevent PTS-induced vessel failure.

Lithuania energy supply constrained with Ignaline-2 shut down

Lithuania’s only operational power plant, Ignalina-2, has shut down permanently, according to the State Nuclear Power Safety Inspectorate (VATESI).

The decision to close the facility was in line with the country’s requirements as a member of the European Union.

A storage facility for the spent fuel is currently being constructed on the site. However, the closure will place great pressure on the economy and Lithuanian citizens as energy supply becomes constrained.

A new nuclear plant is already being planned with an estimated completion date of 2018.

Areva plans to build two plants in California

Parisian nuclear engineering company, Areva, has signed a letter of intent to build up to two nuclear power plants near Fresno, California The agreement with Areva and Central Valley investors is expected to be finalized in March, said a Los Angeles Times report.

The site and valuation process could take up to two years. Despite a California state law banning new builds if the federal government cannot provide plans for permanent storage of spent nuclear fuel, the investors are not discouraged, said the report.

Many in the nuclear industry believe the law is not conducive to California’s urgent energy needs and could change as a result.

The 1,600-megawatt power plants will use European pressurized reactor technology. While financing has not yet been secured, the cost to build the two sites is between an estimated $5bn and $8bn.

Korea Electric Power establishes nuclear education programme

Korea Electric Power Corp. (KEPCO), South Korea's state-run electric company, has been approved by the government to build the world's first graduate studies programme focused on nuclear energy, according to local reports.

The announcement came as South Korea signed a nuclear technology export deal with the United Arab Emirates worth $40bn.

Conveniently locates aside the Kori Nuclear Power Plant in the southern city of Gori, students will have on-site job training, setting an international precedent.

The graduate studies programme will accept 200 students each year offering two-year programmes that will allow students to specialize in nuclear energy planning, operation and maintenance.

The electric company also said the INGS, with a funding near 58billion WON (49.6 million U.S. dollars), plans to accept 200 students per year, offering two-year programmes with specialised courses in nuclear energy planning, operation, and maintenance.

The International Nuclear Graduate School (INGS) is set to open in March of 2012.

NDA makes transition to site licence company

The National Decommissioning Authority’s (NDA) Radioactive Waste Management Directorate (RWMD) has made the transition to a Prospective Site Licence Company (SLC), the authority reported.

“It is very important to us to be able to show that we are successfully transforming this part of the NDA to become an organisation that will ultimately be able to hold a nuclear site licence for a geological disposal facility."

The NDA said that while it is probably many years before a site is selected, they are carrying out preparatory work to support their approach to nuclear safety and environmental management, such as conducting research on how a geological disposal facility could be developed.

Regulators will require RWMD to start operating as a Prospective SLC under voluntary regulatory scrutiny to address the issues raised in their review.

The RWMD Repository Development Management Board has agreed that RWMD will operate, with immediate effect, as a Prospective SLC under voluntary regulatory scrutiny.