In case anyone’s interested, here’s a good paper explaining the EURATOM safeguards system: For instance:

3.3 EURATOM safeguards inspectorate

The EURATOM safeguards inspectorate is a service of the European Commission and has its base in Luxembourg. During 2010, EURATOM’s 150 safeguards inspectors carried out more than 1400 inspections (with about 4000 person-days of inspection). The inspectors are supported by a technical support unit and a nuclear materials accountancy unit.

The EURATOM Treaty gives the Commission the right to send inspectors into the territories of the Member states who shall at all times have access to all places and data and to all persons who deal with materials, equipment or installations subject to safeguards. This right of access can be enforced by the Court of Justice of the EU if necessary. Inspectors are directly employed by the Commission and are therefore independent from their country of origin.

This 2009 paper written by experts from ORNL and CNEN contains a good summary or uranium conversion:

2. TECHNICAL PROCESS FOR NATURAL URANIUM CONVERSION PLANTS

A generic production process for natural uranium conversion normally begins with yellowcake dissolution in nitric acid, followed by a solvent extraction and purification process, followed by a concentration process in an evaporator. These are three common stages to almost any NUCP. Then, one of two main routes may be followed depending on the size of the conversion plant. For small plants (approximately 100–700 MTU/year), precipitation to ammonium diuranate (ADU), ammonium uranyl carbonate (AUC), or uranyl peroxide (UO4uranium dioxide (UO) is followed by calcination to 2). These staged processes are typically operated in batch rather than continuous mode. For medium (>1000 MTU/year) and large (>10,000 MTU/year) plants, a thermal denitration process to convert UN into uranium trioxide (UO3) or triuranium octaoxide (U3O8) is followed by an oxide reduction process to produce UO2. Then regardless of the size of the plant, the UO2 is hydrofluorinated to uranium tetrafluoride (UF4) using hydrogen fluoride (HF). The UF4 can then be fluorinated into uranium hexafluoride (UF6) using fluorine or reduced into uranium metal using magnesium and heat. The simulation of the process is performed using FLOW (a simulation program developed at ORNL).

In case you were looking for a SWU definition, this PNNL paper has one:

The separative work unit (SWU) is a measure of the work expended during an enrichment process that is a function of the concentrations of the feedstock, the enriched output, and the depleted tailings; and is expressed in units which are so calculated as to be proportional to the total input (energy/machine operation time) and to the mass processed.  

This PNNL report has a good description of IAEA safeguards at Brazil’s Resende enrichment facility. Here’s the relevant section on the measures designed to protect some centrifuge design information:

For this facility, the sensitive information to be protected relates to the design of the centrifuges. During inspections, the inspectors have full access to the F&W station to observe and verify measurements of cylinder uranium element and isotope weight. The inspectors have access to the general vacuum station and to the building (confinement). Inspectors also have physical access to the cascade halls but not complete visual access. The facility has been designed to permit visual access to the cascade piping and the main header to permit inspector verification that the configuration has not been changed. The upper piping going to each centrifuge is visible to inspectors; however, the centrifuges are concealed behind panels to protect sensitive design information. In addition, the inspector visual access is sufficient to verify that clandestine piping or unidentified support equipment has not been installed in the portions of the process area outside of the panels that conceal the centrifuges.

The design of this enrichment facility corresponds to one of the more transparent types of conceivable black box facilities. This limited the inspectors’ ability to directly observe some aspects of the configuration of the centrifuge cascade.

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Inspectors also review surveillance data during both interim and unannounced inspections. During interim inspections the review covers the entire period since the last interim inspection. During unannounced inspections, the review is limited to the period since the event that triggered the inspection and the review of camera data is limited to cameras covering critical points.

Inspectors also visit the process areas during routine, interim, and unannounced inspections to verify the design information and to provide assurance that the facility has not been reconfigured to permit misuse. Inspector access to the process areas is governed by agreed-upon procedures to ensure that sensitive information is protected. To verify the configuration of piping in the areas concealed by panels, to which inspector visual access is denied, the operator is asked to take pictures of piping on randomly selected centrifuges.1 These pictures are compared to pictures taken when the cascade first started. The pictures are left at the facility under IAEA and Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials (ABACC) seals. A review of all surveillance camera images within a given period is performed to confirm the absence of undeclared activities or nuclear material. Randomly selected cascade panels and points are used for ‘go – no go’ gamma and transmissivity measurements. This process uses a gamma detector system set up to detect a gamma source situated on the opposite side of the cascade, at the exact position of the detector. The process is then repeated without the source to account for background. The background radiation data measured are expected to be equal to or below the baseline data collected when the cascade was first started because an increase in the gamma radiation level being monitored could be an indication of the presence of higher uranium enrichment levels in the cascade hall.