Fuel utilization potential in light water reactors with once-through fuel irradiation using various reactivity control methods (AWBA Development Program). [PWR]

Technical Report · Fri Sep 01 04:00:00 EDT 1978

DOI:https://doi.org/10.2172/6414020· OSTI ID:6414020

Merriman, F C; McCoy, D F; Capossela, H J; Mendelson, M R

Most U.S. nuclear power plants are light water reactors (LWRs) operating without fuel recycle, i.e., on a once-through basis. To significantly reduce the projected uranium demand, the uranium fuel utilization of the LWRs must be improved. The purpose of the study is to determine the maximum fuel utilization, as measured by energy production per short ton of U/sub 3/O/sub 8/ (Mwy/st U/sub 3/O/sub 8/), achievable by reactor design optimization of a practical once-through PWR. The areas examined for potential gains include the following: reactivity control systems, increased depletion, and the thorium fuel cycle. Although similar gains in fuel utilization could likely be achieved in a BWR, this report concentrates on PWRs. Although fuel utilization could be improved by reducing the diffusion plant tails assay, the report, which deals only with reactor design has assumed that tails assay is held at 0.2% U-235. The following conclusions are drawn from this study: (1) the use of movable fuel for reactivity control results in gains in fuel utilization compared with present types of LWR concepts. (2) For average fuel depletions up to 50,000 Mwd/mt, the uranium fuel cycle requires less U/sub 3/O/sub 8/ consumption than the thorium fuel cycle when the same basic reactor concept is used for both. (3) The gain in fuel utilization due to increased average depletion is small for the uranium fuel system in the range of 35,000 to 50,000 Mwd/mt; for the thorium fuel system, an increase of approx. 10% is calculated over the same depletion range. (4) The maximum gain in fuel utilization for a practical PWR which would incorporate the use of movable fuel without changing the design of the core reflector is about 30%. If a PWR were designed with a power producing exterior blanket that could reduce the neutron leakage from 4% (characteristic of present reactors) to 1%, a maximum overall gain of 50 to 60% in fuel utilization might be realized.

• Research Organization: Knolls Atomic Power Lab., Schenectady, NY (USA)
• OSTI ID: 6414020
• Report Number(s): KAPL-4107
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210200* -- Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
ECONOMICS
FUEL CYCLE
FUEL MANAGEMENT
OPTIMIZATION
PWR TYPE REACTORS
REACTORS
THORIUM CYCLE
WATER COOLED REACTORS
WATER MODERATED REACTORS