NIST is a one-third scale (height) facility located at OSU in Corvallis, Oregon, USA, that replicates the entire NuScale Power Module and reactor building pool.

Electrically heated, it brings the system up to operating temperature and pressure. Stability testing ensures that throughout the expected operating conditions, natural circulation is stable. Furthermore, tests validate computer models including thermal efficiency, performance and safety calculations (Reyes, 2010; Houser et al., 2013). The stainless steel facility operates at full system pressure and temperature and simulates: reactor vessel, rod bundle, core shroud with riser, pressurizer, sump recirculation valves, helical coil steam generator, feedwater pump, containment vessel, and containment cooling pool. NIST scaling ratios are summarized in Table 8.5. A photo and schematic of the NIST containment, pool and pressure vessel is shown in Figure 8.3 (Houser et al., 2013).

ADS nozzles

Pump suction nozzles —

Steam line nozzles

SG helical coils

8.3.1 SMART integral test loop (SMART-ITL) facility

SMART-ITL located at KAERI, Republic of Korea, is a four-loop full-height test facility operating at prototypic conditions (pressure, temperature), and with the area ratio of 1:49 (Park, 2011; NEI, 2013). Its maximum power is 2 MW, or about 30% of

Reactor

pressure

vessel

Reactor

building

pool

Figure 8.3 NIST containment, pool and pressure vessel (from Houser et al., 2013 presentation) the full power scaled down by area ratio. The facility consists of a primary system (simulating integral reactor vessel) with four steam generators, a four-loop secondary system that incorporates four trains of the passive residual heat removal system, each with a heat exchanger, an emergency cool-down tank and a makeup tank, together with valves and connecting pipes. SMART-ITL also incorporates several auxiliary systems. Further information is available in NEI (2013).