Result Summary for the Area 5 Radioactive Waste Management Site Performance Assessment Model Version 4.110

NSTec Environmental Management

关键词: AR FACILITIES;    AIR;    CONSTRUCTION;    DECAY;    FLUX DENSITY;    GROUND DISPOSAL;    LEAD 210;    PERFORMANCE;    PLUTONIUM 239;    RADIOACTIVE WASTE MANAGEMENT;    RADIOISOTOPES;    RADIUM;    RADON 222;    RANGELANDS;    TECHNETIUM 99;    URANIUM 234;    US EPA Performance Assessment;    Area 5 RWMS;    waste management;   

DOI  :  10.2172/1030664
RP-ID  :  DOE/NV/25946--1267
PID  :  OSTI ID: 1030664
Others  :  TRN: US1200640

学科分类：核能源与工程

美国|英语

来源: SciTech Connect

【 摘 要 】

Results for Version 4.110 of the Area 5 Radioactive Waste Management Site (RWMS) performance assessment (PA) model are summarized. Version 4.110 includes the fiscal year (FY) 2010 inventory estimate, including a future inventory estimate. Version 4.110 was implemented in GoldSim 10.11(SP4). The following changes have been implemented since the last baseline model, Version 4.105: (1) Updated the inventory and disposal unit configurations with data through the end of FY 2010. (1) Implemented Federal Guidance Report 13 Supplemental CD dose conversion factors (U.S. Environmental Protection Agency, 1999). Version 4.110 PA results comply with air pathway and all-pathways annual total effective dose (TED) performance objectives (Tables 2 and 3, Figures 1 and 2). Air pathways results decrease moderately for all scenarios. The time of the maximum for the air pathway open rangeland scenario shifts from 1,000 to 100 years (y). All-pathways annual TED increases for all scenarios except the resident scenario. The maximum member of public all-pathways dose occurs at 1,000 y for the resident farmer scenario. The resident farmer dose was predominantly due to technetium-99 (Tc-99) (82 percent) and lead-210 (Pb-210) (13 percent). Pb-210 present at 1,000 y is produced predominantly by radioactive decay of uranium-234 (U-234) present at the time of disposal. All results for the postdrilling and intruder-agriculture scenarios comply with the performance objectives (Tables 4 and 5, Figures 3 and 4). The postdrilling intruder results are similar to Version 4.105 results. The intruder-agriculture results are similar to Version 4.105, except for the Pit 6 Radium Disposal Unit (RaDU). The intruder-agriculture result for the Shallow Land Burial (SLB) disposal units is a significant fraction of the performance objective and exceeds the performance objective at the 95th percentile. The intruder-agriculture dose is due predominantly to Tc-99 (75 percent) and U-238 (9.5 percent). The acute intruder scenario results comply with all performance objectives (Tables 6 and 7, Figures 5 and 6). The acute construction result for the SLB disposal units decreases significantly with this version. The maximum acute intruder dose occurs at 1,000 y for the SLB disposal units under the acute construction scenario. The acute intruder dose is caused by multiple radionuclides including U-238 (31 percent), Th-229 (28 percent), plutonium-239 (8.6 percent), U-233 (7.8 percent), and U-234 (6.7 percent). All results for radon-222 (Rn-222) flux density comply with the performance objective (Table 8, Figure 7). The mean Pit 13 RaDU flux density is close to the 0.74 Bq m{sup -2} s{sup -1} limit.