In Korea, the pressurized water reactor (PWR) is the most common nuclear power plant. Twenty-four PWRs are operating commercially or are under construction. According to the public requirements of the reactor pressure vessel (RPV) surveillance program, all PWR plants have surveillance capsules. The current design life of OPR1000 is 40 years. In order to obtain more accelerated embrittlement characteristics of the RPV material, six surveillance capsules were installed at the OPR1000 RPV inner wall in the downcomer region before the plant began operation. However, the lead factor—defined as the ratio of the fast (E > 1.0 MeV) neutron flux at the surveillance capsule to the fast neutron flux at the RPV peak fluence location—had been estimated at about 1.3 MeV. Therefore, it is difficult to obtain the high-dose irradiation embrittlement data for the life extension. To overcome the small lead factors of OPR1000, supplemental surveillance capsules were fabricated and installed at the Westinghouse plant, which has a relatively high lead factor. This paper discusses the fabrication and installation of supplemental surveillance capsules and the expected withdrawal schedule based on neutron transport calculations and dosimetry evaluations.