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Title: BN-350 unattended safeguards system current status and initial fuel movement data

The Unattended and Remote Monitoring (UNARM) system at the BN-350 fast breeder reactor facility in Aktau, Kazakhstan continues to provide safeguards monitoring data as the spent fuel disposition project transitions from wet fuel storage to dry storage casks. Qualitative data from the initial cask loading procedures has been released by the International Atomic Energy Agency (IAEA) and is presented here for the first time. The BN-350 fast breeder reactor in Aktau, Kazakhstan, operated as a plutonium-producing facility from 1973 W1til 1999. Kazakhstan signed the Nonproliferation Treaty (NPT) in February 1994, and shortly afterwards the IAEA began safeguarding the reactor facility and its nuclear material. Slnce the cessation of reactor operations ten years ago, the chief proliferation concern has been the spent fuel assemblies stored in the pond on-site. By 2002, all fuel assemblies in wet storage had been repackaged into proliferation-resistant canisters. From the beginning, the IAEA's safeguards campaign at the BN-350 included a constant unattended sensor presence in the form of UNARM which monitors nuclear material activities at the facility in the absence of inspector presence. The UNARM equipment at the BN-350 was designed to be modular and extensible, allowing the system to adapt as the safeguards requirements change.more » This has been particularly important at the BN-350 due to the prolonged wet storage phase of the project. The primary function of the BN-350 UNARM system is to provide the IAEA with an independent, radiation-centric Containment and Surveillance (C&S) layer in addition to the standard seals and video systems. The UNARM system has provided continuous Continuity of Knowledge (COK) data for the BN-350's nuclear material storage areas in order to ensure the validity of the attended measurements during the lifetime of the project. The first of these attended measurements was characterization of the spent fuel assemblies. This characterization utilized the Spent Fuel Coincidence Counter (SFCC) instrument [ref] to measure neutron multiplicity and calculate Pu mass. These calculated masses were then compared to modeling simulation of the assemblies as well as declarations from the facility in order to baseline the amount of material under IAEA safeguards [ref]. Once the baseline was established, bundles of four or six assemblies were repackaged into proliferati n-resistant canisters. This provided an additional physical barrier to material diversion and provided further protection by choosing assemblies for each canister so that the overall dose rate met self-protection requirements. Each of the canisters were then characterized using a similar technique to the SFCC, but with the Spent Fuel Attribute Monitor (SPAM) instnunent (ref). The data from these measurements were then used to calculate an attribute proportional to the total Pu mass in each canister. This attribute was then compared to the know Pu mass of each assembly in order to verify the accuracy of SPAM. In the event that COK is lost, the SPAM detector remains positioned to reverify Pu content of individual canisters without requiring the canister to be opened.« less
Authors:
 [1] ;  [1] ;  [1] ;  [2]
  1. Los Alamos National Laboratory
  2. IAEA
Publication Date:
OSTI Identifier:
989825
Report Number(s):
LA-UR-09-03682; LA-UR-09-3682
TRN: US1007162
DOE Contract Number:
AC52-06NA25396
Resource Type:
Conference
Resource Relation:
Conference: Institute of Nuclear Materials Management ; July 13, 2009 ; Tucson, AZ
Research Org:
Los Alamos National Laboratory (LANL)
Sponsoring Org:
DOE
Country of Publication:
United States
Language:
English
Subject:
21; 46; 98; BREEDER REACTORS; CASKS; CONTAINERS; CONTAINMENT; DOSE RATES; DRY STORAGE; FUEL ASSEMBLIES; IAEA; IAEA SAFEGUARDS; KAZAKHSTAN; MONITORING; NEUTRONS; NON-PROLIFERATION TREATY; NUCLEAR MATERIALS MANAGEMENT; PROLIFERATION; REACTOR OPERATION; SAFEGUARDS; SPENT FUELS; STORAGE; WET STORAGE