U1.03/02 OSA activities at Zaporozhye Nuclear Power Plant (AP ref.7.2.1.1)

The present project is a continuation of on-site-assistance (OSA), rendered by RWE Energy as the EC appointed Consultant to Zaporoshe NPP.

This project had 2 main different categories of objectives and tasks:

Provision of "soft" OSA, Project Management Unit support for PIP, comprising:
Transfer of best Western practices (estimated work duration 36 months);
Project Management Unit support: preparation of tender and contract dossiers, evaluation of offers, placing the supply and service contracts, implementation project management, licensing support. (estimated work duration 48 months);
Improvement of valve systems on primary and secondary circuits, (estimated project duration 48 months) comprising:
U1.03/02B1: Replacement of Steam Generator Safety Valves (units 1-6);
U1.03/02B2: Improvement of Pressurizer Safety Valves (units 1-4);
U1.03/02B3: Replacement of Feedwater Control Valves (units 1-4).
Aim and justification for the replacement/improvement projects:

The current valves are not qualified for feed and bleed for operation with water/water-steam mixture, this may lead to failure to close. They also have a lever drive design which is not permitted anymore.
The current valve system has no redundant means to be opened for feed and bleed operation, second the valve design allows no measures for closure after failure to close and the operator has no position indication for the pilot valve position.
The current valves are improper functioning in case of transients having a large impact on the reliable control of the steam generator level, i.e. events of load reduction and even reactor trips were repeatedly recorded.

The project progressed and has reached most of the specified aims. In particular the 3 procurement specifications have been established and the procurement process has been performed. Contractual project end was 05.06.2007.