ORNL-4191 - the Molten Salt Energy Technologies Web Site

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2225 Mw (thermal) MSBR
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97
Table 7.2. Pumps for Breeder Reactors
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Fuel Hlanke t Coolant
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Number required 4” .la 4*
Design temperature, OF 1300 1300 1300
Capacity, gpm 11,000 2000 16,000
Head, ft 150 RO 150
Speed, rprn 1160 1160 1160
Specific speed, N 2830 2150 3400
Net positive suction head required, ft 25 8 32
Impeller input power, hp 990 250 1440
150 Mw (thermal) MSBE
Number required 1 1 1
Design temperature, OF 1300 1300 1300
Capacity, gpm 4500 540 4300
Head, ft 150 80 150
Speed, rpm 1750 1750 17.50
Specific speed, N 2730 1520 2670
Net positive suction head required, ft 27 5 26
Impeller input power, hp 410 61 390
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a,
I’he same total number of DUIIIPS - - is reauired for a 1000-Mw (electrical) plant of the MSRR
reference desiw or nodular design.
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deem necessaiy. However, it would appear more
economical to perform the molten-salt bearing de-
velopment work at OIINL, where the fuel produc-
tion facilities and the handling techniques are
already available. Proof testing of completed
pumps in molten salt prior to operation in either
tlw ETU or the MSBE will be conducted at ORNL.
Endurance testing of prototype pumps in molten
salt will also be conducted at ORNL in the proof-
testing facilities.
Because experience indicates that production of
suitable and reliable salt pumps is one of the
longest lead-time items for molten-salt reactor ex-
periments, it is important to get an early start in
the pump program.
If study indicates that the NISBE salt pumps can
be operated subcritically but that the MSBR pumps
must be operated supercritically, then the con-
ditional objective may require operation of a salt
pump at supercritical speeds during the course of
the MSBE program to build confidence in the
reliability of a pump with such a long shaft,
Fuel and Blanket Salt Pumps
Preliminary layouts have been made for the fuel
salt pump, blanket salt pump, and coolant salt
pimp. The concepts of the fuel salt pumps, shown
in Fig. 7.5, and the blanket salt pump are similar,
having a shaft of the order of 34 ft long, supported
by an oil-lubricated radial and thrust bearing at
the upper end and a molten-salt-lubricated journal
bearing near the impeller at the lower end. The
main differences in the two pumps lie in (1) the
size of the fluid flow passages to, through, and
from the impeller, (2) the absence of a pump tank
on the blanket salt pump, and (3) the sizes of the
drive motors. The similarity of the pumps which
is derived from their common environment and
placement within the cell results in common
analytical and developmental efforts in the areas
of bearings, seals, rotor dynamics, motor containment,
general layout, direct and remote maintenance,
ancillary systems, fabrication and assembly,
and nuclear heating.
The fuel salt and blanket salt pumps are designed
so that the rotary element which contains
all the moving parts can be replaced by remote
maintenance without having to cut any of the salt
lines to or from the pump. Direct maintenance can
be performed on the drive motor and the bearingseal
assembly at the upper end of the pump. A
static seal can be brought into play to separate
and protect the maintenance area from the radioactivity
in the pump when the bearing-seal assembly
is to be removed