3315 SEAWAY BLVD 2020-06-05 - Laserfiche WebLink

TERRAPOWER Radiation Dispersion Sketch and Narrative [ 1111111f f11111111111 [ IIItIIIIIII 0 5' 10' 15' 25' Iii iii i I The radioactive materials that TerraPower will receive and work with will mostly be contained within shielding systems (e.g., a cask or a shielded glovebox). Approximately once per month, TerraPower will receive a shipment and will need to unpack the cask in order to transfer the material into one of our shielded containers that, in turn, will be transferred into our shielded glovebox. During that unpacking process, the material will briefly (less than an hour) be revealed within the shielded room. The walls of this room, conservatively, are twice as thick as required (24" versus 12") The graphic above shows a gray region that represents our stay-out zone where the dose rate will exceed 2 millirem per hour (2 mrem/h). This is only the case within the room itself or at its top, with a person leaning in. Dose rates are much lower in all other locations, including on the roof of the Seaway building. Regulations require that workers receive less than 2.5 mrem/h in most cases, so TerraPower's dose rate, which is only present during these limited operations, does not pose a problem. Nevertheless, we will use administrative controls to maintain the dose as low as reasonably achievable and will not perform such operations if activities are underway up on the roof. Documentation detailing the above has been provided by TerraPower to the Washington State Department of Health. /5"./