Impact of the Proposed Addition of 3 Un-extracted Cycle 6 TPBARs to the Lead Test Assembly

Hiergesell, Robert A

Savannah River Site (S.C.)

关键词: Radioactive Waste Disposal;    Tritium;    Ground Water;    Source Terms;    42 Engineering;   

DOI  :  10.2172/881504
RP-ID  :  WSRC-RP-2005-01788
RP-ID  :  DE-AC09-96SR18500
RP-ID  :  881504

美国|英语

来源: UNT Digital Library

【 摘 要 】

The Tritium Readiness Program is planning to ship three (3) additional unextracted Tritium Producing Burnable Absorber Rods (TPBARs) in the Lead Test Assembly (LTA) container to SRS for disposal. These rods are from the PIE (Post Irradiation Examination) program that is currently underway at ANL-W and will not have been extracted. The three rods were irradiated in Watts Bar Cycle 6 (irradiation was completed on February 22, 2005) after which they were sent to ANL-W for neutron radiography and gamma scanning. Once arriving at SRS, the LTA will be placed within the first TPBAR disposal container which will then be disposed within the Intermediate Level Vault (ILV). To determine the potential impact with respect to those performance measures, this UDQE addresses the proposed action to include the 3 PIE TPBARs, with an associated 2.8E+04 Ci of tritium, within the LTA. The first TPBAR disposal container was previously evaluated to determine its suitability for disposal within the ILV in a Special Analysis (SA), see Hiergesell and Wilhite, 2004. At the time that investigation was conducted the plan was to place 32 unextracted TPBARs containing {approx}1.71E+05 Ci of tritium within the LTA. In addition to this, the first TPBAR disposal container is expected to contain 900 extracted TPBARs with an associated {approx}1.2E+05 Ci of tritium. That study concluded that the placement of the disposal container, along with the LTA and its original contents, could be disposed within the ILV without causing any exceedance of DOE Order 435.1 performance measures. It should be noted that the 900 extracted TPBARs are a bounding case for the purposes of the SA and that the current best estimate is that only 474 extracted TPBARs will actually be placed in the container. In Hiergesell and Wilhite, 2004, one of the major considerations in determining suitability for disposal was evaluating the release of tritium from the disposal container and its subsequent migration from the ILV into the groundwater flow system. Part of the tritium source term in that investigation was the estimated tritium permeation rate from the LTA container, which is housed within the larger TPBAR disposal container. The calculation of the LTA tritium permeation rate was documented in a separate report, Vinson, et. al., 2004.