Year
2001
Abstract
Extensive data acquisitions were completed to understand and describe the observed neutron backgrounds in F-wing of the Savannah River Technology Center (SRTC). The previous observation that the neutron background is not decaying with the expected 2.64- yr half-life of 252Cf is explained by the data that have identified contributions to the neutron background from (238Pu) Be and (239Pu) oxide sources. We have acquired gamma-ray spectra and neutron background rates from twenty-three selected locations. The neutron acquisitions have identified four points of high flux that dominate the overall event rates and dose rates observed. Two of the spots include a laboratory module and a storage module, have been positively identified by the gamma-ray spectra to have dominant contributions from the decay of 239Pu and 238Pu. The neutron acquisitions taken near these modules have neutron singles rates of up to 33000 cps and neutron coincidence rates that are equal to zero within statistical uncertainty. These data together are consistent with neutron rates that are dominated by (a, n) reactions from the (238Pu) Be and (239Pu) oxide sources whence they originate. Our results are shown to conform perfectly to process knowledge of the distribution of neutron producing sources stored in F-wing of SRTC. This paper will discuss the approach, methodology, results, conclusions, and recommendations.