Dose Rate Evaluation for Spent Fuel Aging Areas at Yucca Mountain

Abstract

The spent nuclear fuel (SNF) aging system at the proposed Yucca Mountain repository will provide site-specific casks and aging pads for thermal management of commercial SNF with a heat rate in excess of the waste package thermal output limit. An aging pad can accommodate 1,000 MTHM of SNF, containing a total of 100 aging casks with a horizontal module of 20 casks, and 80 vertical site-specific casks arranged in a 2 x 40 array. The proposed aging system will provide five aging areas in two separate locations. The first location will contain a single pad designated as Aging Area 17A (1,000 MTHM capacity). The second location will contain Aging Areas 17B through 17E (20,000 MTHM total capacity), each consisting of five aging pads arranged in a compact rectangular configuration. This paper presents calculated dose rates as a function of distance from Aging Areas 17A and 17B through 17E. In addition, the paper evaluates the effect of design parameter variations on dose rates with focus on spacing between casks and spacing between pads in Aging Areas 17B through 17E.