Maximum mass in unit is 3.1 kg. (An extra 20% was modeled for NDA uncertainty.) canister [7.1.1] Operators trained on procedures and postings Absorber N/A N/A Analysis neither relies on nor uses absorbers N/A Geometry H/D = 0.92 N/A Process uses cylinders with H/D=0.92 Purchasing procedures specify canister dimensions [7.1.1] Interaction Single canister Extra canister Procedure limits carrier to one canister [7.1.2] Operators trained on procedures Concentration N/A N/A Process does not involve solutions N/A Moderation 65% polyethylene by volume limiting matrix N/A Canister flooded Procedure requires that containers be closed and locked Purchasing specifications require water-tight containers Enrichment N/A N/A Worst possible enrichment (100% Pu-239) assumed N/A Reflection Canister on floor in the corner of the room, surrounded by 12” thick slabs of water to represent nearby personel..against a surface or corner of the room [NOTE from professor: The student should have made it clearer that “held” meant operator hands were around the canister.] Canister fully reflected by sprinkler water. Building procedures require sprinkler system maintenance to assure proper operation Sign-off maintenance sheet kept on sprinkler system Purchasing rules
APPENDIX D COMMENT REVIEW SHEETS [NOTE from professor: Yours should say “(Not used in this evaluation)”] # Comment Resolution Initials 1 Remove Appendix F page Agreed it should remain in report XYZ 2 Remove reference to Revision 3 Reference removed XYZ 3 Include a paragraph on QA procedure QA paragraph added XYZ 4 Remove posting #3 requiring removal only as needed (unnecessary with procedures) Posting Removed CDE 5 Show parametric study evaluations Parametric studies added to output CD CDE 6 Show normal case for geometry Normal case added CDE 7 Show normal case for interaction Normal case added CDE 8 Difficulty in reproducing exact keff Difficulty attributed to difference in computers CDE
Type of Concrete keff Uncertainty ORCONCRETE 0.9856 0.0029 RFCONCRETE 0.9815 0.0031 REG-CONCRETE 0.9835 0.0026 MGCONCRETE 0.9835 0.0031 The type of concrete that resulted in the highest keff was the concrete. Therefore it will be the one used for modeling. Parametric Study 2: Effect of Wall Presence of Canister This parametric study determines the effect of modeling the canister with and without walls. The canister is modeled without walls with a 7-inch diameter and a ratio of 0.92. The canister with walls adds a stainless steel-304 wall thickness of 1/16-inch. Both models surround the canister with 1-inch of water for simulation of hands. The canister contains 4 kg of Pu-239 and is polyethylene (CH2) by 65% volume with the remainder of the volume filled with air. The keff for each scenario is as follows. keff Uncertainty With Canister Wall 0.6361 0.0029 Without Canister Wall 0.6419 0.0029 Effect of Canister Wall 0.0058 - The effect of the canister walls is approximately a 0.6% decrease in keff. The canister walls can thus be ignored and have a conservative keff. Parametric Study 3: Most Reactive Placement of Canister This parametric study determines the most conservative location to model the canister that gives the highest keff. The canister is modeled containing 4 kg 65% polyethylene (CH2) by volume, and the remainder of the volume filled by air. The canister is modeled with a 7-inch diameter and a height–to-diameter ratio of 0.92 and is surrounded by 1-inch water to simulate hands. The canister will be modeled in three positions. A corner surrounded by 12-inch concrete walls and floors. 2. A corner against a 12-inch concrete wall and floor and against a 3/16-inch stainless steel-304 wall representing a cabinet 3. A corner against a 3/8-inch stainless steel-304 sheet with a 1/16-inch layer of lead to represent the glovebox and a 12-inch concrete wall. This model applies a conservative location of the glovebox being against a wall.
This analysis does not take into account the presence of any other canisters. The results for each placement are shown below. Position keff Uncertainty 1 0.7565 0.0030 2 0.7271 0.0030 3 0.6592 0.0029 Based on this parametric study the worst modeling of reflection in regards to canisters location occurs when the canister is placed on the concrete floor in the corner of the walls.