Real-Time Detection Methods to Monitor TRU Composition in the UREX + Process Stream

Abstract:

The Real-Time Detection Methods to Monitor TRU Composition in the UREX + Process Stream project is a large project consisting of three students and two professors from Texas A & M University and groups at Purdue University, University of Illinois, and Argonne National Laboratory. The sub-project that involves the NSSPI program consists of safeguarding the URanium EXtraction (UREX)+1a reprocessing process.

URUREX is a reprocessing process that the United States and the Global Nuclear Energy Partnership (GNEP) is investigating as an alternative to Plutonium URanium EXtraction (PUREX). UREX can greatly reduce the radiological waste while being inherently proliferation resistance because the plutonium in spent fuel is kept with minor actinides so it cannot be directly used in nuclear bomb material. Even though the UREX process is inherently proliferation resistant it still needs to be safeguarded. Since the plutonium is never fully separated, as in PUREX, it is harder to measure than in PUREX.

The UREX +1a process was chosen because the curium is kept with the plutonium product (See Figure 1 for a schematic). This makes for an interesting measurement because the number of neutrons from curium will be several orders of magnitude more than the number of neutrons from plutonium. The UREX +1a also appears to be a promising choice if the UREX process is pursued further.

This project is looking at traditional safeguards methods like those implemented at the Rokkasho Reprocessing Plant and new methods and detector systems such as the Tensioned Meta-stable Fluid Detector (TMFD) and methods being developed as part of the Coupled End-to-End Demonstration (CETE).The TMFD is being investigated for the use of online alpha spectroscopy to quantify plutonium in solution in real-time. CETE involves the use of coupled photon and neutron measurements to quantify plutonium in spent nuclear fuel. Real-time plutonium measurement paired with process monitoring is also being investigated.

The goal of this project is to develop detector requirements and safeguard processes needed for a certain Material Balance Period or to provide a Material Balance Period for a given safeguards system. Interested parties include the Department of Energy (DOE), the International Atomic Energy Agency (IAEA), the Nuclear Regulatory Commission (NRC), and the facility operators.