skip to main content

Title: OPTIMIZATION OF HETEROGENEOUS UTILIZATION OF THORIUM IN PWRS TO ENHANCE PROLIFERATION RESISTANCE AND REDUCE WASTE.

Issues affecting the implementation, public perception and acceptance of nuclear power include: proliferation, radioactive waste, safety, and economics. The thorium cycle directly addresses the proliferation and waste issues, but optimization studies of core design and fuel management are needed to ensure that it fits within acceptable safety and economic margins. Typical pressurized water reactors, although loaded with uranium fuel, produce 225 to 275 kg of plutonium per gigawatt-year of operation. Although the spent fuel is highly radioactive, it nevertheless offers a potential proliferation pathway because the plutonium is relatively easy to separate, amounts to many critical masses, and does not present any significant intrinsic barrier to weapon assembly. Uranium 233, on the other hand, produced by the irradiation of thorium, although it too can be used in weapons, may be ''denatured'' by the addition of natural, depleted or low enriched uranium. Furthermore, it appears that the chemical behavior of thoria or thoria-urania fuel makes it a more stable medium for the geological disposal of the spent fuel. It is therefore particularly well suited for a once-through fuel cycle. The use of thorium as a fertile material in nuclear fuel has been of interest since the dawn of nuclear power technologymore » due to its abundance and to potential neutronic advantages. Early projects include homogeneous mixtures of thorium and uranium oxides in the BORAX-IV, Indian Point I, and Elk River reactors, as well as heterogeneous mixtures in the Shippingport seed-blanket reactor. However these projects were developed under considerably different circumstances than those which prevail at present. The earlier applications preceded the current proscription, for non-proliferation purposes, of the use of uranium enriched to more than 20 w/o in {sup 235}U, and has in practice generally prohibited the use of uranium highly enriched in {sup 235}U. They were designed when the expected burnup of light water fuel was on the order of 25 MWD/kgU--about half the present day value--and when it was expected that the spent fuel would be recycled to recover its fissile content.« less
Authors:
;
Publication Date:
OSTI Identifier:
15009919
Report Number(s):
BNL--73152-2004
R&D Project: 86382 AND 86392; 820101000; TRN: US0406822
DOE Contract Number:
AC02-98CH10886
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 1 Aug 2004
Research Org:
BROOKHAVEN NATIONAL LABORATORY (US)
Sponsoring Org:
DOE/OFFICE OF SCIENCE (US)
Country of Publication:
United States
Language:
English
Subject:
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; 11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; 12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; 29 ENERGY PLANNING, POLICY AND ECONOMY; ENRICHED URANIUM; ERR REACTOR; FERTILE MATERIALS; FUEL CYCLE; FUEL MANAGEMENT; HOMOGENEOUS MIXTURES; NUCLEAR FUELS; NUCLEAR POWER; OPTIMIZATION; POLONIUM 216; PROLIFERATION; PWR TYPE REACTORS; RADIOACTIVE WASTES; SPENT FUELS; THORIUM; THORIUM CYCLE; URANIUM 233; URANIUM OXIDES; WASTES