Abstract
Dominion Generation (Dominion) has procured replacement containment sump strainers for their nuclear fleet to address issues identified in Nuclear Regulatory Commission (NRC) Generic Safety Item-191 (GSI-191). Atomic Energy of Canada Ltd. (AECL) has designed and tested Finned Strainers^[○!R] as replacement strainers for six of Dominion's reactors, including Millstone Power Station Unit 2 (Millstone 2). The initial surface area and interstitial volume (fin pitch) of the Finned Strainer for Millstone 2 were sized based on the design conditions, debris loading and size restrictions provided by Dominion, and on the NUREG/CR-6224 correlation. Testing of a prototype test section consisting of three fins and two interstitial spaces was conducted to establish the final required surface area and interstitial volume. Head loss testing was conducted under both thin-bed and full-debris load conditions. Measured head losses compared favourably to the NUREG/CR-6224 correlation. Fractions of fiber and particulate bypass were also measured. Final validation testing of a full-scale prototype strainer module consisting of eight fins and a header was conducted to confirm that the strainer design met the head loss requirements for Millstone 2. Measured head losses were in good agreement with measurements from the reduced-scale tests.
