Presented at the IAEA conference in October 2003

ABSTRACT

Upon IAEA request, the French Support Program to IAEA Safeguards has developed a new device for the control of the irradiated LEU and MOX fuels. The Safeguards Mox Python (SMOPY) is the achievement of a 4 years R&D program supported by CEA and COGEMA in partnership with EURISYS MESURES. The SMOPY system is based on the combination of 2 NDA techniques (passive neutron and room temperature gamma spectrometry) and on line interpretation tools (automatic gamma spectrum interpretation,depletion code EVO). Through the measurement managing software, all this contributes to the fully automatic measurement, interpretation and characterization of any kind of spent fuel.

The device is transportable (50kg,60cm) and is composed of four parts:

1. the measurement head with one high efficiency fission chamber and a micro room temperature gamma spectrometric probe,
2. the carrier which holds the measurement head. The carrier bottom fits the racks for accurate positioning and its top fits operator‘s fuel moving tool,
3. the portable electronic cabinet which includes both neutron and gamma electronic cards,
4. the laptop PC which gets inspectors data, controls the measurement, get measured values, interprets them and immediately provides the inspector with worthwhile information for appropriate on the field decisions.

Main features of SMOPY are:

• discrimination of MOX versus LEU irradiated fuels in any case,
• full characterization of irradiated LEU (burnup, cooling time, Pu amounts… ),
• Partial Defect Test on LEU fuels.

A first version of SMOPY was tested in industrial condition during summer 2000. This tests showed a need of shielding improvement around the gamma detector. A new version has been built and the LEU to MOX distinction feature will be qualified during a new field test.

INTRODUCTION

The SMOPY ¹ (Safeguards Mox Python) device was developed upon IAEA request in the frame of the French Support Program. Basically the SMOPY device is based on the methodology developed for the PYTHON system devoted to irradiated fuels measurements for safety criticality purposes. Main differences come from the Agency requirements that are summarized in the following paragraph. The paper describes the system itself, then main features are explained.