Background For more than 35 years, Westinghouse has cut reactor vessel internals. For some plants, this was done in the frame of reactor pressure vessel internals (RPVIs) replacement as part of life-cycle extension programs. In some other cases, Westinghouse cut internals in plants under decommissioning. The underwater mechanical cutting technique has been used in all boiling water reactors (BWRs) since 1999.

Typically, pressurized water reactor (PWR) reactor internals segmentation and packaging projects include a separation of the highly activated material (that is, baffle plates, core formers, core region of the core barrel, core support plate and in-core instrumentation thimbles) from the rest of the material (that is, core barrel remnants, core support assembly, thermal shield and upper internals).