Criticality Safety Controls for 55-Gallon Drums with a Mass Limit of 200 grams Pu-239

Chou, P

Lawrence Livermore National Laboratory

关键词: Criticality;    Plutonium;    Reflection;    Paraffin;    Steels;   

DOI  :  10.2172/1034515
RP-ID  :  LLNL-TR-521191
RP-ID  :  W-7405-ENG-48
RP-ID  :  1034515

美国|英语

来源: UNT Digital Library

【 摘 要 】

The following 200-gram Pu drum criticality safety controls are applicable to RHWM drum storage operations: (1) Mass (Fissile/Pu) - each 55-gallon drum or its equivalent shall be limited to 200 gram Pu or Pu equivalent; (2) Moderation - Hydrogen materials with a hydrogen density greater than that (0.133 g H/cc) of polyethylene and paraffin are not allowed and hydrogen materials with a hydrogen density no greater than that of polyethylene and paraffin are allowed with unlimited amounts; (3) Interaction - a spacing of 30-inches (76 cm) is required between arrays and 200-gram Pu drums shall be placed in arrays for 200-gram Pu drums only (no mingling of 200-gram Pu drums with other drums not meeting the drum controls associated with the 200-gram limit); (4) Reflection - no beryllium and carbon/graphite (other than the 50-gram waiver amount) is allowed, (note that Nat-U exceeding the waiver amount is allowed when its U-235 content is included in the fissile mass limit of 200 grams); and (5) Geometry - drum geometry, only 55-gallon drum or its equivalent shall be used and array geometry, 55-gallon drums are allowed for 2-high stacking. Steel waste boxes may be stacked 3-high if constraint.