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Nuclear Safety Cooperation

U1.02/92A1 : Ultrasonic Inspection React

Benefitting Zone
Eastern Europe
€ 173,615.10
EU Contribution
Contracted in 1996
Technical Assistance to the Commonwealth of Independent States


Type of activity

Design Safety



Contracting authority

European Commission

Method of Procurement

Informal Consultation


09/07/1996 - 09/08/1997


Goskomatom (Ukraine)



Project / Budget year

WW9508 Nuclear Safety 1995 / 1995


The project was launched in TACIS 93 program as a continuation of the project launched under the TACIS 92 annual program. The original project was split into two main items; Non Destructive Testing (NDT) of the RPV, U 1.02.92 A1 and Radiation Embrittlement Surveillance Plan (RESP) U 1.02/92 A2. The NDT part incuded originally also supply of NDT equipment, but it was cancelled due to close interface with the SK-187 Manipulator Modernisation project, which was prepared for the TACIS 95 Annual Program Plan.


The objective of the project was to provide the plant staff with modern equipment, technology, training and procedures to carry out and evaluate the reactor pressure vessel in-service inspection (RPV ISI).


A detailed study of documents on “RPV programme proposal” and “Specification for the Ultrasonic Inspection of RPVs” in order to elaborate the content of the defined project Tasks, documents and procedures to be issued, training courses to be implemented and other technical assistance was carried out. Necessary information on next RPV ISI, ultrasonic inspection procedures used, Ukrainian standards, and calibration blocks available was provided by the SUNPP. A comparative study was carried out between Ukrainian inspection standards and the ASME code regarding the ultrasonic inspection procedures related to:

inspection volume;
personnel qualification;
calibration blocks;
sensitivity levels;
UT scans;
acceptance criteria.
This document, which was published only in Russian language, includes the following elements:

Methodology to carry out a mechanised ultrasonic inspection. This document describes a typical work schedule to be followed for the preparation of a mechanised ultrasonic inspection.
General specification for calibration blocks. In this document the characteristics that should meet the blocks for sensitivity calibration are described.
The reflectors of existing calibration blocks at SUNPP were upgraded to meet new standard requirements.
An exception were the calibration blocks for manual inspection of the threaded zones in vessel flange and for the ultrasonic inspection by the LLT tandem technique. In these two cases new calibration blocks design were proposed. The drawings of the blocks were included in the document.
Procedure for the ultrasonic inspection of reactor vessels WER-1000 type, which deal with the ultrasonic testing of the following vessel areas:
welds and base metal of the RPV core region region (welds 2, 3 and 4);
the bottom electroslag weld and adjacent base metal(weld 1);
nozzle region circumferential welds (welds 5, 6 and 7);
MCL nozzle welds (Diameter 850 mm);
ECCS nozzle welds.
Procedure for the ultrasonic inspection of threaded zones in vessel flange of VVER 1000 type of NPPs.
A training course of 3 weeks for shift leaders and analysts was organized at TECNATOM headquarters. The training course dealt with the following subjects:

inspection preparation;
UT procedures;
data acquisition and analyses systems;
specific ultrasonic inspection techniques;
advanced ultrasonic sizing techniques of indications.
Another training course was divided in twenty-two different modules written in Russian language and the handbooks were handed over to each one of the six attendants. The training courses included practical UT training in laboratories at Technatom using laboratory inspection mock up with immersion tank.

The final training course was organized in SUNPP at site for data acquisition system operators, with a 8 days duration. During these courses automatic inspection training on LLT tandem technique were implemented and RPV inspection procedures were discussed for final approval.

The overall all results of this project can be summarized as follows:

It has been supplied to SU NPP according the new requirements of the standards in force in Ukraine and also suitable to the modern inspection systems existing on the market.
SUNPP has been provided with the technical specification and drawings for the calibration blocks, designed according the requirements of the new vessel inspection procedures.
By the training courses the personnel of SUNPP has been introduced in the standards and ultrasonic inspection and sizing techniques, normally used in western countries and also the necessary didactic material has been handed over.
It has been provided the necessary technical assistance for licensing and validation of procedure.
There were difficulties in commencing this project due to the discovery of a close interface between this and another project as mentioned above in the project background.

Nevertheless, the project was very well implemented and completed successfully according to the TS.

Further Information
Further information on the project results could be sought from the beneficiary organizations as well as from EC archives.

The Project Final report is available at the JRC-IE archive.