A $150 million project is underway to replace the reactor vessel head at Ameren Missouri's Callaway nuclear plant in Missouri.
The work is being carried out during a scheduled refuelling and maintenance outage, which began on 11 October and is due to be completed later this month.
Thousands of other maintenance activities, including the replacement of 84 of the 193 nuclear fuel assemblies are also being completed.
Replacement of Callaway's original vessel head, which dates back to 1984 when the reactor started up, is described as one of the largest maintenance activities in the plant's history and will ensure the continued safe and reliable operation of the reactor, Ameren says.
Vessel closure heads, which are typically made of low alloy steel and clad with stainless steel, have in the past experienced corrosion damage and are being replaced in many PWRs.
The 180-ton replacement vessel head for Callaway was manufactured by AREVA in Europe and delivered to the Callaway site this summer. The component and the integrated head assembly took five years to manufacture, AREVA said.
Callaway, an 1190 MW Westinghouse pressurized water reactor is currently licensed to operate until 2024, but has applied for an additional 20-year operating licence extension with the Nuclear Regulatory Commission.
Photo: Callaway Energy Center