Reactor pressure vessel integrity assessment
Reactor pressure vessel integrity assessment
Description
Objective
The main objective of this project was to get the results of re-embrittlement experiments using available spare templates from Novovoronezh 3&4 as well as the necessary data and method assessment in order to confirm or to improve the results of previous Tacis programmes.
More detailed, the tasks of the project are:
Task 1:
Performance of accelerated re-embrittlement experiments for validation of relevant re-embrittlement kinetics.
Performance of accelerated re-embrittlement experiments for validation of relevant re-embrittlement kinetics.
Task 2:
Establishment of data files for the reference PTS assessment.
Establishment of data files for the reference PTS assessment.
Task 3:
Establishment and validation of kinetic hardness method.
Establishment and validation of kinetic hardness method.
Task 4:
Re-evaluation of the crack initiation toughness/temperature curve.
Re-evaluation of the crack initiation toughness/temperature curve.
Task 5:
Presentation of all the results to the local Safety Authorities.
Presentation of all the results to the local Safety Authorities.
Task 6:
Supply of computer systems to the Beneficiary.
Supply of computer systems to the Beneficiary.
Result
The result meets the objective in general. The most important result of the project was the achievement of a clear understanding about the actual status of the available technical data.
The project resulted in rather clear conclusions and recommendations for the further steps needed to predict reliably the residual life time of the NV-3&4 RPVs.
Task 3 results based on the local subcontractor’s work indicate that the joint use of the kinetic hardness and magnetic methods might be applicable for the follow-up of the embrittlement status of the RPVs by using NDT methods. However, a definitive conclusion on the basis of the results obtained so far is not possible. A new project for that specific purpose would be needed in order to solve that issue.
Task 4 resulted in an upgraded fracture toughness/temperature, which due to the deficiencies in the quality of the existing data, however, does not fully meet the reliability requirements. Proposals for improving the situation are presented.
The objectives were achieved as planned. The project somewhat increased the local awareness about the present knowledge status in respect of the VVER 440/230 RPV re-embrittlement and possibilities to predict the residual life time reliably. Still a lot of uncertainties regarding re-embrittlement kinetics remain.
The contacts established at the expert level form a good basis for follow-on actions considered as necessary for improving the knowledge status in the long term.
General Information
Title:
Reactor pressure vessel integrity assessment
Programme:
TACIS
Amount:
€ 687.090,36
Budget year:
1995
Countries:
Russia
Nature:
Services
Types of activities:
Design safety
Sector:
DS - Design safety (incl. Off-Site Emergency Preparedness)
Duration (months):
26
Contracting authority:
European Commission
Contractors:
EDF (Electricite de France)
Status:
Closed
CRIS number:
25195
Old reference:
97-0710
Project reference:
R2.02/95
Decision number:
TACIS/1995/000-408
Method of procurement:
Restricted Call for Tender
Signature date:
22/12/1997
Effective contract date:
22/12/1997
Contract end date:
22/02/2000
Closure date:
22/02/2000
Contract Documents:
