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Conceptual design for a re-entrant type fuel channel for supercritical water-cooled nuclear reactors

Current CANDU-type nuclear reactors use a once-through fuel-channel with an annulus
gas insulating it from the moderator. The current reference design for a CANDU-type
SuperCritical Water-Cooled Reactor (SCWR) is to eliminate the annulus gap and use a
ceramic insert to insulate the coolant from the moderator. While such a design may
work, alternative fuel-channel design concepts are under development to explore the
optimum efficiency of SCWRs. One such alternative approach is called the Re-Entrant
fuel-channel.
The Re-Entrant fuel-channel consists of three tubes, the inner tube (flow tube), pressure
tube and an outer tube. The fuel bundles are placed in the inner tube. An annulus is
formed between the flow and pressure tubes, through which the primary coolant flows. A
ceramic insulator is placed between the pressure tube and the outer tube. The coolant
flows through the annulus receiving heat from the inner tube from one end of the channel
to another. At the far end, the flow will reverse direction and enter the inner tube, and
hence the fuel-string. At the inlet, the temperature is 350°C for a high-pressure coolant
(pressure of 25 MPa), which is just below the pseudocritical point. At the outlet, the
temperature is about 625ºC at the same pressure (the pressure drop is small and can be
neglected). The objective of this work was to design the Re-Entrant channel and to
estimate the heat loss to the moderator for the proposed new fuel-channel design.
A numerical model was developed and MATLAB was used to calculate the heat loss
from the insulated Re-Entrant fuel-channel along with the temperature profiles and the
heat transfer coefficients for a given set of flow, pressure, temperature and power
boundary conditions. Thermophysical properties were obtained from NIST REFPROP
software. With the results from the numerical model, the design of the Re-Entrant fuelchannel
was optimized to improve its efficiency / UOIT

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OOSHDU.10155/144
Date01 April 2011
CreatorsSamuel, Jeffrey
ContributorsHarvel, Glenn, Pioro, Igor
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeThesis

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