Measuring and monitoring KIPT Neutron Source Facility Reactivity

Technical Report · Sat Aug 01 04:00:00 EDT 2015

DOI:https://doi.org/10.2172/1224197· OSTI ID:1224197

Cao, Yan ^[1]; Gohar, Yousry ^[1]; Zhong, Zhaopeng ^[1]

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1. Argonne National Lab. (ANL), Argonne, IL (United States)

Argonne National Laboratory (ANL) of USA and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on developing and constructing a neutron source facility at Kharkov, Ukraine. The facility consists of an accelerator-driven subcritical system. The accelerator has a 100 kW electron beam using 100 MeV electrons. The subcritical assembly has k_eff less than 0.98. To ensure the safe operation of this neutron source facility, the reactivity of the subcritical core has to be accurately determined and continuously monitored. A technique which combines the area-ratio method and the flux-to-current ratio method is purposed to determine the reactivity of the KIPT subcritical assembly at various conditions. In particular, the area-ratio method can determine the absolute reactivity of the subcritical assembly in units of dollars by performing pulsed-neutron experiments. It provides reference reactivities for the flux-to-current ratio method to track and monitor the reactivity deviations from the reference state while the facility is at other operation modes. Monte Carlo simulations are performed to simulate both methods using the numerical model of the KIPT subcritical assembly. It is found that the reactivities obtained from both the area-ratio method and the flux-to-current ratio method are spatially dependent on the neutron detector locations and types. Numerical simulations also suggest optimal neutron detector locations to minimize the spatial effects in the flux-to-current ratio method. The spatial correction factors are calculated using Monte Carlo methods for both measuring methods at the selected neutron detector locations. Monte Carlo simulations are also performed to verify the accuracy of the flux-to-current ratio method in monitoring the reactivity swing during a fuel burnup cycle.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation (NA-20)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1224197
• Report Number(s): ANL--15/15; 121380
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
43 PARTICLE ACCELERATORS
ACCELERATORS
ACCURACY
BEAM CURRENTS
COMPUTERIZED SIMULATION
COORDINATES
CORRECTIONS
DOLLARS
ELECTRON BEAMS
MEASURING METHODS
MEV RANGE 10-100
MONITORING
MONTE CARLO METHOD
NEUTRON DETECTORS
NEUTRON FLUX
NEUTRON SOURCE FACILITIES
NEUTRONS
OPERATION
REACTIVITY
SUBCRITICAL ASSEMBLIES
UKRAINE