U2.02/96 - system for steam generator

According to the TOR the aim of the project was to assist the Ukrainian nuclear industry to attain the knowledge and skills in improved Western techniques, developed for increasing efficiency, shortening downtime and reducing radiation doses in steam generator replacement projects, in order to apply them to the future SG replacements at VVER type reactors. The focus was especially on the issues related to:

• Adaptation of narrow gap welding for use in SG replacement at Ukrainian NPPs
• Documentation for the certification of the narrow gap welding process
• Use of tools and equipment for the cutting, aligning, fitting, welding and thermal stress relief of the piping connected to the SG to be replaced.

The specific objective was to develop a strategy and project plan as well as the key technologies required for the SG replacement at the Ukrainian VVER plants with appropriate training of the maintenance personnel from the NPPs and engineering support organisations. Zaporozhe NPP Unit 3 was identified in the TOR as the reference plant for the project implementation.
According to the TOR, the project comprises the following technical tasks:

• Task 2 - Identification and assessment of the technical constraints
• Task 3 - Generation of the strategy for SG replacement
• Task 4 - Definition and development of specific technologies including application of narrow gap welding techniques for SG replacement
• Task 5 - Creation of a management and quality system
• Task 6 - Production of an outline project plan, time and critical path schedules and risk analysis
• Task 7 - Organising and providing training courses
• Task 8 - Specification and procurement of selected equipment.

The following outputs were achieved by the end of the contract :

Output (Task 2): Technical Constraints Report was issued on 15.11.1999 and distributed on 04.02.2000 .

Output (Task 3): Strategy Report on SG replacements in Ukraine was issued on 10.03.2000 and distributed on 08.06.2000. It contains, however, an important mistake in respect of the weld edge dimensions for narrow gap welding (see T3-RE 006, Page 43, Figure 2.3-9). This is a key issue in the nozzles of the existing spare SGs, a reason why the new welding technology cannot be applied before re-machining of the nozzle weld ends.

Output (Task 4): Implementation Reports on specific technologies were produced during period 16.08.2000 –25.10.2000 and distributed from 20.11.2000 to 22.12.2000.
Output 2: ‘Guidelines for welding, qualification and experience’ produced on 16.08.2000 and distributed on 22.12.2000.

Output (Task 5): documents ‘Steam Generator Replacement, Project management recommendations’, ‘Steam Generator Replacement, On-site organisation’ and Steam Generator Replacement, Quality Assurance Program’ were produced on 25.10.2000 and distributed on 05.03.2001

Output (Task 6): the documents ‘Overall Work Sequence Plan’, ‘SGR Performance Schedule’ and ‘SGR Performance Recommendations’ were produced from 26.01.2001 to 29.03.2001 and distributed on 06.06.201.

Outputs (Task 7): The planned outputs were not fully achieved (see table above).
Output 1: Four documents have been only produced instead of six reports originally planned.
Output 2: The training courses are successfully completed.
• Welding
Five specialists were trained on the use of the narrow gap welding equipment during the training courses, which took place from 19.03.2001 to 30.03.2001 in France.
• Cutting and machining
Four specialists were trained on the use of the cutting and machining equipment during the training courses, which took place from 07.05.2001 to 11.05.2001 in Spain.
• Optical survey
Four specialists were trained on the use of the optical survey equipment during the training courses, which took place from 23.04.2001 to 27.04.2001 in France.

Outputs: (Task 8) The planned outputs were not fully achieved
Output 1: The Technical specifications for Orbital NGTAW and for Cutting and Bevelling equipment were produced on 25.10.2000 and 19.12.2000 respectively. They were finally distributed on 12.02.2001 and 12.02.2001.
Output 2: Two sets of the narrow gap welding and one set of the cutting/ bevelling equipment were delivered to Ukraine on 16.06.2001 and 21.06.2001. The customs clearance completed on 11.09.2001.

(from MONIS database - END OF PROJECT ASSESSMENT REPORT No. 7)