Brian D Boyer

Advanced Safeguards Approaches for New Reprocessing Facilities

U.S. efforts to promote the international expansion of nuclear energy through the Global Nuclear Energy Partnership (GNEP) will result in a dramatic expansion of nuclear fuel cycle facilities in the United States. New demonstration facilities, such as the Advanced Fuel Cycle Facility (AFCF), the Advanced Burner Reactor (ABR), and the Consolidated Fuel Treatment Center (CFTC) will use advanced nuclear and chemical process technologies that must incorporate increased proliferation resistance to enhance nuclear safeguards. The ASA-100 Project, “Advanced Safeguards Approaches for New Nuclear Fuel Cycle Facilities,” commissioned by the NA-243 Office of NNSA, has been tasked with reviewing and developing advanced safeguards approaches for these demonstration facilities. Because one goal of GNEP is developing and sharing proliferation-resistant nuclear technology and services with partner nations, the safeguards approaches considered are consistent with international safeguards as currently implemented by the International Atomic Energy Agency (IAEA). This first report reviews possible safeguards approaches for the new fuel reprocessing processes to be deployed at the AFCF and CFTC facilities. Similar analyses addressing the ABR and transuranic (TRU) fuel fabrication lines at AFCF and CFTC will be presented in subsequent reports.

Advanced Safeguards Approaches for New TRU Fuel Fabrication Facilities

This second report in a series of three reviews possible safeguards approaches for the new transuranic (TRU) fuel fabrication processes to be deployed at AFCF – specifically, the ceramic TRU (MOX) fuel fabrication line and the metallic (pyroprocessing) line. The most common TRU fuel has been fuel composed of mixed plutonium and uranium dioxide, referred to as “MOX”. However, under the Advanced Fuel Cycle projects custom-made fuels with higher contents of neptunium, americium, and curium may also be produced to evaluate if these “minor actinides” can be effectively burned and transmuted through irradiation in the ABR. A third and final report in this series will evaluate and review the advanced safeguards approach options for the ABR. In reviewing and developing the advanced safeguards approach for the new TRU fuel fabrication processes envisioned for AFCF, the existing international (IAEA) safeguards approach at the Plutonium Fuel Production Facility (PFPF) and the conceptual approach planned for the new J-MOX facility in Japan have been considered as a starting point of reference. The pyro-metallurgical reprocessing and fuel fabrication process at EBR-II near Idaho Falls also provided insight for safeguarding the additional metallic pyroprocessing fuel fabrication line planned for AFCF.

New generation enrichment monitoring technology for gas centrifuge enrichment plants

We report our progress toward development of new generation on-line enrichment monitoring technology for UF6 gas centrifuge plants based on a transmission source and a NaI spectrometer. We use an X-ray tube with transmission filters instead of a decaying isotopic transmission source to eliminate the costly replacement of this source. The UF6 gas density measurement is based on the energy dependency of the mass attenuation for two characteristic X-ray lines generated by the transmission filters. An analytical expression for the UF6 density is derived and criteria for the selection of transmission energies are discussed. Because of the differential method of measurement, the UF6 gas density does not depend on the intensity of the X-ray source. We describe a design of a sealed UF6 gas test stand for development testing and calibration of various on-line enrichment monitoring instruments. The sealed source is intended to replace a UF6 gaseous loop currently used for calibration.

Advanced Safeguards Approaches for New Fast Reactors

This third report in the series reviews possible safeguards approaches for new fast reactors in general, and the ABR in particular. Fast-neutron spectrum reactors have been used since the early 1960s on an experimental and developmental level, generally with fertile blanket fuels to “breed” nuclear fuel such as plutonium. Whether the reactor is designed to breed plutonium, or transmute and “burn” actinides depends mainly on the design of the reactor neutron reflector and the whether the blanket fuel is “fertile” or suitable for transmutation. However, the safeguards issues are very similar, since they pertain mainly to the receipt, shipment and storage of fresh and spent plutonium and actinide-bearing “TRU”-fuel. For these reasons, the design of existing fast reactors and details concerning how they have been safeguarded were studied in developing advanced safeguards approaches for the new fast reactors. In this regard, the design of the Experimental Breeder Reactor-II “EBR-II” at the Idaho National Laboratory (INL) was of interest, because it was designed as a collocated fast reactor with a pyrometallurgical reprocessing and fuel fabrication line – a design option being considered for the ABR. Similarly, the design of the Fast Flux Facility (FFTF) on the Hanford Site was studied, because it was a successful prototype fast reactor that ran for two decades to evaluate fuels and the design for commercial-scale fast reactors.

Implications for Advanced Safeguards Derived from a Proliferation Resistance and Physical Protection Case Study for a Generation IV Nuclear Energy System

The Proliferation Resistance and Physical Protection Evaluation Methodology Working Group of the Generation IV International Forum produced a full-system case study on the Example Sodium Fast Reactor Nuclear Energy System (ESFR-NES). The ESFR-NES is a hypothetical fuel cycle complex consisting of four sodium-cooled fast reactors of medium size collocated with an on-site dry-fuel storage facility and a spent-fuel reprocessing facility based on electrochemical recycling technology. The complex recycles irradiated fuels from two feed streams, oxide fuel from off-site light water reactors and metal fuel from the on-site sodium-cooled fast reactors. Both of these streams are recycled on-site; uranium and transuranics are sent to the electrochemical reprocessing fuel cycle facility. The two streams combine and the fuel cycle facility creates new ESFR-NES metal fuel for the four on-site sodium-cooled fast reactors. The major safeguards concepts driving the safeguards analysis were timeliness goals and material quantity goals. Specifically, the recycled fuel, the in-process material in the fuel reprocessing facility, the off-site light water reactor spent fuel received at the ESFR-NES, and spent fuel from the on-site fast reactors will contain plutonium. The International Atomic Energy Agency defines the material within the ESFR-NES as “direct-use material” with a stringent timeliness goal of 3 months and a material quantity goal of 8 kg of plutonium. Furthermore, the ESFR-NES may have some intrinsic safeguards features if the plutonium and uranium are not separated during reprocessing. This facility would require major modifications to separate the plutonium from other transuranic elements in the reprocessed fuel. The technical difficulty in diverting material from the ESFR-NES is at least as strongly impacted by the adversaries’ overall technical capabilities as it is by the effort required to overcome those barriers intrinsic to the nuclear fuel cycle. The intrinsic proliferation resistance of the ESFR-NES can affect how extrinsic measures in the safeguards approach for the complex will provide overall proliferation resistance.