DISPOSAL OF SEALED TRANSURANIC RADIOACTIVE SOURCES AT THE WASTE ISOLATION PILOT PLANT

While the activities leading to the opening of the Waste Isolation Pilot Plant (WIPP) have been complex, many challenges remain. In the case of newly generated debris waste consisting of excess and unwanted sealed transuranic (TRU) radioactive sources, one of those challenges is for the Carlsbad Field Office (CBFO) of the U.S. Department of Energy (DOE) to demonstrate the use of acceptable knowledge (AK) as necessary and sufficient to preclude the need of having to perform additional confirmatory characterization measurements. The Waste Analysis Plan (WAP) of the WIPP Hazardous Waste Facility Permit (HWFP) issued by the New Mexico Environment Department (NMED) [1] requires radiography and/or visual examination (VE) and headspace gas (HGAS) sampling and analysis to be performed on all waste containers to confirm AK and to update and modify initial AK assessments. Also, the Compliance Certification Decision (CCD) issued by the U.S. Environmental Protection Agency (EPA) [2] requires all waste containers to be radioassayed. The physical, chemical, and radiological properties of the sealed radioactive sources were well documented at the time of their manufacture. If the sources remain sealed throughout their lifetime, these properties remain well defined at the time of packaging into a TRU waste form acceptable for WIPP disposal. The CBFO has initiated an effort to assemble the required AK documentation and, based on this documentation, to request the use of experiments, computations, or collaborating data in lieu of the 100 percent confirmatory characterization measurements required in the WAP and the CCD. Fundamental to the simple nature of the sealed radioactive sources and their known properties, the significance of this alternative approach to certifying them for disposal at WIPP is reduced worker exposure, higher throughput, and significantly reduced characterization costs. These benefits are achievable without compromising worker safety, human health, or the environment. The process and basis for submitting a permit modification request (PMR) to the NMED will be discussed. This modification seeks to allow Los Alamos National Laboratory (LANL) the flexibility to characterize HGAS volatile organic compound (VOC) concentrations in the waste stream by using non-radioactive surrogates that represent the typical sealed source packaging configurations, by using experimental results, or by calculation. The strategies and alternatives to be used by the CBFO in preparing a proposed change in the waste characterization activities at LANL for determining the radionuclide composition of sealed sources are discussed in a companion paper to be given at this meeting [3]. Sealed sources, as used in this document, are those devices manufactured to be a sealed source as defined in a position paper generated by the DOE/NV Radioactive Waste Acceptance Program and the Nevada Test Site Waste Acceptance Criteria Working Group, concurred with by the Nevada Division of the Environmental Protection Agency, and cited in the DOE Nevada Operations Office Position on Characterization and Disposal of Radioactive Sealed Sources, Revision 2, October 5, 1998.