skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Longitudinal flux flattening

Technical Report ·
DOI:https://doi.org/10.2172/10148125· OSTI ID:10148125

To date a great deal of emphasis has been placed on flattening the side-to-side and top-to-bottom flux distribution with only minor effort to improve the front-to-rear distribution. Minor variations in the front-to-rear distribution have been achieved by horizontal control rod and Supplemental control positioning. It has-been reasonably well established that the rupture potential for one tube charge increases markedly with higher specific power and temperature; thus there is a great deal of incentive to flatten in the front-to-rear dimension. Although flattening in this dimension will caure increased neutron leakage out of the reactor, this is compensated by increased conversion efficiency resulting from a more uniform exposure distribution within the tube charge. The purpose of this document is to describe the basic analytical methods and the techniques, of flattening front-to-rear through the integrated use of enrichment and poison material in combination with natural uranium, and to point out the requirements to insure that total control criteria is satisfied in the event of a water loss with this loading. For the purpose of this survey report an old reactor, 32-piece charge length, and a symmetrical front-to-rear distribution were considered; however, the methods given can be extended quite easily to different length and non-symmetrical charges and to the K reactors.

Research Organization:
General Electric Co., Richland, WA (United States). Hanford Atomic Products Operation
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC06-76RL01830
OSTI ID:
10148125
Report Number(s):
HW-66089; ON: DE94011271
Resource Relation:
Other Information: DN: Declassified; PBD: 19 Jul 1960
Country of Publication:
United States
Language:
English