Flux flattening vertical fluence and power profiles

Technical Report · Tue Aug 01 04:00:00 EDT 1989

OSTI ID:720051

Finfrock, S H

In order to better understand and predict the graphite expansion in the core of N Reactor, it is necessary to have data on the total high energy neutron fluence experienced by the reactor over its lifetime and some estimations of what it will experience in the future. This information needs to be space dependent to allow structural analysis of different moderator regions of the core in three dimensions. The available data set is the total power generation of the process tubes for each charge/discharge cycle. These values can be summed to obtain a total exposure value for each tube over the lifetime of the reactor (or any shorter time period of interest). Average fluence for each tube can then be calculated directly from the total power generation. This information, in conjunction with some calculations, can be related to localized graphite fluence values. The power distributions used to expand historical exposure data into three-dimensional fluence values are calculated from a Base Case (all MKIV in the central zone) model. The Base Case model was developed for the 6% operating mode (6 wt% Pu-240 in plutonium). The N Reactor, however, has operated in at least three distinct modes: 6%, including coproduct (1967 to 1968); 12% (1971 to 1982); and flux flattening transition (1986 to 1/7/87). These results are therefore most applicable to the 6% operating mode. The data will, however, be conservative for graphite distortion estimates in the peak flux regions because the 12% and flux flattening modes had flatter axial power profiles. 3 refs., 1 fig., 1 tab.

• Research Organization: Westinghouse Hanford Co., Richland, WA (United States); Westinghouse Hanford Co., Richland, WA (USA)
• DOE Contract Number: AC06-87RL10930
• OSTI ID: 720051
• Report Number(s): WHC-SP--0499; ON: TI90020043
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
DAMAGE
DATA ACQUISITION
DATA ANALYSIS
GRAPHITE
N-REACTOR
NEUTRON FLUENCE
NEUTRON FLUX FLATTENING
NUMBER CODES
RADIATION DOSES
REACTOR FUELING