Qualification of UDG equipment for nuclear power plants

Context and challenges

Following the Fukushima accident, the French Nuclear Safety Authority (ASN) issued technical specifications, one of which requires the entire nuclear fleet to be equipped with an "ultimate" emergency power source. The client, a leading player in the nuclear industry, has installed an Ultimate Diesel Generators (UDG) on each of its 56 reactors at all the nuclear power plants, except at the Fessenheim nuclear power plant. These are installed in "bunkered" buildings designed to resist ultimate risks.

These generators are designed to withstand possible attacks (earthquakes, floods, tornadoes), which are far more important than those taken into account in the design of the installations and during safety reassessments. For this reason, they are subject to a qualification process for accident conditions.

This client, and more specifically its department dedicated to the engineering of the fleet, in terms of deconstruction and the environment, has asked Assystem to support in the monitoring of qualification documents, to assist some suppliers and to take over the drafting of the Qualification Maintenance Sheets (QMS).

Project scope

Support for the monitoring of qualification documents:

This work consisted in reviewing all the qualification documentation (qualification programmes, test specifications, test reports, Qualification Summary Notes (QSN), Qualification Maintenance Sheets and formalizing the remarks in draft monitoring sheets. The main materials concerned were: batteries, rectifier-chargers, electrical cabinets, MV and LV (High Voltage A/Low Voltage) panels, control-command cabinets.

Support for some suppliers:

At the client's request, Assystem assisted some suppliers by taking charge of drafting certain parts of the qualification documents.

Takeover of the drafting of the Qualification Maintenance Sheets (QMS):

The QMFs drawn up by the suppliers having been deemed unsuitable by the operator, Assystem was asked by the client to take over the drafting of all the QMFs for the UDG equipment.

Client benefits

Issuance of more than 300 draft monitoring sheets to support the monitoring of qualification documents
Reinforced support from 3 suppliers: a company specialising in batteries and rectifier-chargers, another specialising in LV and HV electrical boxes, as well as a supplier of control-command boxes
Takeover of the editorial staff of 70 QMS