An inverted hydride-fueled pressurized water reactor concept

Previous studies conducted at MIT showed that power performance of typical pin geometry PWRs are limited by three main constraints: core pressure drop, critical heat flux (CHF) and fretting phenomena of the fuel rods against grid spacers. The present work investigates the possibility to reduce the limiting effect exerted by these constraints by radically changing the core geometry, rather than by only taking measures to address specific constraints. The geometry modification consists of inverting the relative position of fuel and coolant, thus generating the so-called inverted geometry. An inverted assembly consists of a fuel prism perforated with cylindrical, vertically oriented, cooling channels, arranged in a triangular lattice. A pin vs inverted comparison, performed at cell level, shows that an inverted geometry can attain the same fuel volume fraction of the pin geometry but with a much lower pressure drop and fuel temperature. Also, CHF performance can be enhanced, relative to the pin geometry, by inserting multiple short-length twisted tapes (MSLTTs) inside the cooling channels, and fretting concerns do not apply since spacer grids are not needed. When the pin vs inverted comparison is performed at whole-core level, the same conclusion on pressure drop and fuel temperature apply to reactor types in which, thanks to low operating pressure and/or fuel-coolant chemical compatibility, the inverted core can be designed as to closely resemble a modular repetition of the inverted unit cell, i.e. the so-called continuous inverted geometry.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Nuclear Science and Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2010

Author dc:creator

• Ferroni, Paolo, Ph. D. Massachusetts Institute of Technology

Advisor dc:contributor.advisor

• Neil E. Todreas.

• Nuclear Science and Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/57879

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/57879