The pump sumps were also designed for molten nitrate salt service at 1049°F (565˚C) with a maximum temperature of 1085°F (585˚C). The sumps were designed to accommodate the pumps, heaters and instrumentation with as small of a diameter as practical. Their height was determined by considering a worst case scenario of all the available salt in the system equalizing in height in the sump plus the salt from the heat exchangers back flowing into the sumps.

    The sumps are constructed of 304 stainless 16 inch NPS SCH 40 pipe. The interior is 60 inches deep to accommodate maximum salt charge described above. The flange is 16NPS 150# class. Sump inlet pipe is located 8 inches from the bottom of the tank and is 3/4 NPS. Insulation is 6 inches of SuperWool blanket around the sump with 6 inches of Microporous board supporting the tanks below.

    The sumps are internally heated by a 3kW heater in a NPS 4 thermowell.

    The sumps are each equipped with a drain valve, which will allow the sumps to drain entirely for maintenance purposes.