R2.02/05A - Implementation of risk monitoring technology at NPP's with VVER 1000 reactors (V-320)

As part of the TACIS 2005 programme, the European Commission funded a project to implement Risk Monitor technology at VVER-1000 reactors in the Russian Federation.
Risk monitoring technology has been widely used both to determine the instantaneous risk depending on the availability of plant systems and components, and to assist with plant safety management over the time.

To benefit from the application of probabilistic safety assessment techniques, the Russian Federation supported the development of plant specific Probabilistic Safety Assessment (PSA) models for many of the plants in the country. Although the quality of the current studies varied from plant to plant, it was recognized that the studies which had been performed to acceptable standards, could strongly influence the design and operation of nuclear power plants. Furthermore, the reconciliation of probabilistic and deterministic insights was considered as a powerful tool for optimizing safety decision making processes at NPPs.

In order to ensure technical quality of the PSA studies in Russia, Rostechnadzor issued rules applicable to PSA studies.

Rosenergoatom developed and approved a “Programme of activities aimed at improving PSA applications at operating NPPs” [AES PRG-109K04] for 2004-2009. One of the key issues specified in this programme concerned the development and implementation of “Risk Monitor” tools at the Russian nuclear power plants as one of the PSA applications.

Russia requested technical assistance from the EU in the support of a project that would consider development and implementation of risk monitoring technology at VVER-1000 NPPs with Balakovo NPP being the pilot plant to implement such a technology. This assistance involved both technical support needed for development of a risk-monitoring tool and transfer of know-how on how to use it to the Balakovo NPP operational staff.

TACIS Design Safety projects were service or consultancy type projects that were able to address research, design and engineering issues. They were usually implemented in such a way that an EU research, design or engineering organisation worked in close collaboration with Beneficiary country counterpart organisations on a specific technical problem.

The design safety projects therefore achieved a dual purpose of providing the necessary technical resources to solve the issue of concern whilst at the same time transferring know-how and developing capabilities within the Beneficiary country organisations wherever a lack had been identified. This dual purpose also helped to provide the sustainability of the project benefits that was a major objective of the TACIS programme.

The main objective of this TACIS Project was to provide the technical assistance and the know-how transfer needed, and to help the Russian operator Rosenergoatom to implement risk monitoring technology at NPPs with VVER-1000 reactors.

The project was implemented through two contracts:

1. the first with an EU expert organisation, Iberdrola (contract 116767; project R2.02/05), also referred to in the following as 'the Consultant';
2. the second with the Russian nuclear design and engineering organisation, Atomenergoproekt [AEP] (contract 145422; project R2.02/05A), also referred to in the following as the 'Director of PSA' or DoP.

The present summary contains information either about the results of the activities performed by the consultant and by the DoP.

The objectives and achievements of the overall project are described below.

The scope of the project was divided in the following activities:

• Task 1 Project Management.
  • Subtask 1.1 Project Preparation.
  • Subtask 1.2 Review of the international up-to date technical and organizational methodologies and operational experience gained in relation to the implementation and use of Risk Monitor at NPP’s.
• Task 2 Familiarization with Balakovo Unit 1 PSA model.
  • Subtask 2.1 Review of the Living PSA model available for Balakovo NPP.
  • Subtask 2.2 Revision of the Balakovo NPP Living PSA model.
• Task 3 Delivery of the risk monitor technology, including appropriate PSA toolbox.
  • Subtask 3.1 Selection of the software to be used for the purpose of the project.
  • Subtask 3.2 Delivery of the Risk Monitor software toolbox to be used for the purpose of the project.
• Task 4 Development of risk monitor probabilistic model on the basis of Balakovo NPP living PSA level 1.
• Task 5 Installation of risk monitoring toolbox at Balakovo NPP and risk monitor trial operation.
• Task 6 Training of Russian experts in the development and use of risk monitoring technology.
• Task 7 Preparation of final report.

The project dealt with the first Risk Monitor developed in Russia according to international Standards. In order to implement this technology, three main phases were developed. Phase 1: Improving the PSA quality to achieve IAEA Standards for this kind of application. Phase 2: Developing the risk monitor model using appropriate software. Phase 3: Transfer the know-how on risk monitoring technology. Balakovo NPP was selected by the Russian utility Rosenergoatom as the pilot plant.

A summary of the results of the overall project, according to project Tasks, is given below.

 

Task 1 Project Management

Subtask 1.1 Project Preparation

The aim of this task was to prepare all organizational, financial and managerial aspects of the Project. During the performance of the Task 1, the Project Kick-off Meeting took place on 20^th February 2008 at AEP premises. The Objective of that meeting was launching the Project activities of both the Consultant and Director of PSA (DoP), ensuring that all stakeholders have the same understanding of the project as well as defining any shortcomings that were previously not known. The project team was set up with members of all involved organizations. During the contract period, two Steering Committee Meetings took place.

The software initially selected by the Consultant for the project implementation was finally not available. It was necessary to purchase another software with which neither Iberdrola nor AEP were familiar.

A modification to the Balakovo operation fuel cycle and a power uprate was implemented at the beginning of 2009. The plant requested that these changes should be implemented in the PSA in order to have a state-of-the-art model. It was agreed that this would be beneficial to Rosenergoatom and Balakovo NPP.

Taking into account that additional work was needed to address the above mentioned facts, the Steering Committee agreed to accept for consideration requests for project extension. Taking into account the Consultant proposal to finish the project without additional funds, the EC issued the addendum to the Contracts.

The period of implementation of the project was extended up to 36 months and the scope of work was established to develop and validate a power operation PSA model, removing from the scope of the project the shutdown model.

During the contract period, different Progress Meetings took place.

On Subtask 1.1 DoP performed specifically the following works:

1. Definition of working team.
2. Preparation of project time schedule. Participation of DoP in the preparation and process of the Kick-of Meeting (KoM) and the preparation of the Inception Report.
3. In the accordance to ToR DoP provided the office spaces for the KoM and also for other meetings which have taken place in Moscow during 2008 – 2010 years.

DoP proposed to organize the non-foreseen in the ToR seminar for familiarization of the EC Consultant with Balakovo unit 1 PSA model. 

Subtask 1.2: Review of the international up-to-date technical and organizational methodologies and operational experience gained in relation to the implementation and use of RISK Monitor tools at NPPs

This task included:

• The review of the Risk Monitoring practices that are supported by international nuclear organizations (IAEA and NEA).
• The review of the best international practices on the use of Risk Monitors that are applied by nuclear power plants.
• The description of a reference EU NPP operational practices related to the use of Risk Monitor, including the procedures that have been used by the plant during the trial Risk Monitoring operation.

This review integrated the performance, safety and economic aspects related to the use of these technologies as well as lessons learnt from the implementation of such systems at NPPs.

During the performance of this Task, a visiting tour was organized in Spain to two different NPPs which have implemented and have been using a Risk Monitoring Tool for practical applications in operation. This Technical Tour took place from 22 to 26 September 2008. The tour included the following activities:

• Visit to Ascó NPP and access to the main control room risk monitor.
• Visit to Cofrentes NPP and access to the main control room.
• Visit to Spanish Regulatory Body: ‘Consejo de Seguridad Nuclear’.
• Visited EPRI Risk & Reliability European meeting to show the software.

The team of Russian specialists who participated in the technical tour included three experts from the Energoatom Concern, five experts from the Balakovo NPP, and two experts from JSC Atomenergoproekt (DoР).

At this time, it was concluded from the results of the technical tour that the Risk Monitoring technology EOOS, initially proposed by the Consultant, was in line with the objectives of the R2.02/05 project, and that the conditions specific for Russian NPPs could be taken into account in developing the RM model for Unit 1 of the Balakovo NPP.

 

Task 2 Familiarization with Balakovo Unit 1 PSA model

Subtask 2.1: Review of the Living PSA model available for Balakovo NPP

The aim of this task was to perform initial review of the quality and completeness of the PSA model. This included review of the electronic PSA model as well as available PSA documentation. A systematic, comprehensive and well documented review of the main PSA elements was performed.

During the performance of this Task, a seminar was arranged in order for AEP to present the Balakovo PSA to experts of Iberdrola. This seminar was carried out at AEP offices in Moscow from 27 to 30 May 2008. During the seminar, AEP handed over to Iberdrola a CD with the notebooks and the models for both Power PSA and Shutdown PSA, and some tables with the success criteria.

As for the review of the PSA of Balakovo NPP, a Procedure to review the PSA was developed and sent to the Beneficiary, End User and European Commission. This procedure was based on IAEA-TECDOC-1511.

Iberdrola evaluated the quality of all PSA elements: Initiating Events Analysis, Accident Sequence Analysis, Success Criteria Formulation and Supporting Analysis, Systems Analysis, Human Reliability Analysis, Data Analysis, Dependent Failures Analysis, Model Integration and Core Damage Frequency Quantification, and Results Analysis and Interpretation.

On the basis of the Consultant's review, the DoP updated and improved the PSA models.

On subtask 2.1 DoP performed the following specific works:

Preparation and delivery to Iberdrola previous Living PSA documentation and electronic models for NPP power operation and shutdown states which were developed using the PSA level 1 by JSC Atomenergoproekt and Gidropress in the 2007 year for unit 1 of Balakovo NPP. In this report it is given the description of the T/H analyses results which are performed by Gidropress for the definition of success criteria for accident sequences modelling.

Subtask 2.2 Revision of the Balakovo NPP Living PSA model

The aim of this task was to review if all of the recommendations for improvement of the Balakovo NPP Living PSA model were properly addressed by the DoP and the PSA model was amended accordingly and also to confirm the required quality of the Living PSA electronic models and PSA documentation.

In order to fulfil this task, different meetings between Iberdrola, AEP and Balakovo NPP took place.

Regarding this task, Iberdrola sent different comments to AEP. The last comments on the Living PSA, related to shutdown systems, were sent to AEP on 12 January 2009. All comment sheets were completed and returned by AEP.

A meeting between AEP and IBERDROLA was held at AEP premises from 25 to 27 May 2009 to solve the comments related to all items. AEP sent the documentation and new model of LPSA in Power Operation (“POWER 18.RSD”) and during Shutdown (“SHUT 18.RSD”) on 1st October 2009 and 8th October 2009, respectively. The new revision of PSA included documental and model modifications in accordance with:

• Conclusions of Task 2.1 Technical Report;
• New success criteria and manual operations based on the new thermohydraulic calculations performed by Gidropress;
• Plant modifications due to the modernization measures implemented in Balakovo- NPP before 31st December 2008.

AEP sent the first frozen model on February 2010. AEP sent final model and final documentation on March 2010. Last frozen model was sent the 24/03/2010.

The main objective of DoP works on the subtask 2.2 was to prepare and deliver to Iberdrola revised (“frozen”) Living PSA model and documentation for using their by Iberdrola at the development of Risk Monitor model.

 

Task 3: Delivery of the risk monitor technology, including appropriate PSA Software toolbox

Subtask 3.1 Selection of the software to be used for the purpose of the project

Iberdrola initially issued a subtask report that summarized the results from the software selection process and proposed the risk monitor software toolbox to be used for the purpose of the Project. Taking into account the task report conclusions, EOOS was selected to be used as the risk monitor toolbox for the purpose of the project.

After some discussions, however, an agreement between AEP/REA and EPRI could not be reached to the purchase of EOOS.

Iberdrola representatives held a meeting at RelconScandpower premises on February 3^rd 2009 in order to identify the benefits and limits of RiskWatcher software tool, as an alternative.

In order to consider the new decision to be taken regarding the software to be used for the implementation of risk monitor at Balakovo NPP, a meeting was held on 12 February 2009 in Moscow with representatives of Energoatom, AEP, Balakovo, EC and Iberdrola.

The conclusion of this meeting was that - although the software EOOS was the best software for this project -, the impossibility for the End User to obtain it made Risk Watcher the best alternative.

This is because there were difficulties for EOOS software license delivery to AEP and REA and due to risk to break the Contract schedule AEP proposed to replace the EOOS with Risk Spectrum Risk Watcher (RSRW) computer code.

But, it was also mentioned that the lack of experience with Risk Watcher in the industry could affect the project development 

Subtask 3.2: Delivery of the Risk Monitor software toolbox to be used for the purpose of the project

The aim of this task was to provide support and arrange for DoP and Balakovo NPP to receive the appropriate software required to implement Risk Monitor technology at Balakovo NPP.

Iberdrola received Risk Spectrum and Risk Watcher 1.20 evaluation version and started the familiarization with this software. Iberdrola detected a bug on this version so Relcon sent a new version 1.21. Iberdrola informed that as this software has a lack of experience, more errors could appear and cause delays to the project.

Iberdrola supervised all technical work needed to adapt the Risk Monitor Tool to the needs of Balakovo NPP, including the necessary translation to Russian of Risk Monitoring Display Screens.

Regarding the schedule of the project: AEP bought Risk Watcher software code from Relcon (August 2009). AEP, Balakovo and Iberdrola received the code (September 2009). AEP reviewed the translation to Russian of the user manual (October 2009). AEP reviewed the translation to Russian language of the software screens (November 2009).

All necessary software required to implement the Risk Monitor tool at Balakovo NPP was received, tested and installed.

 

Task 4 Development of Risk Monitor probabilistic model on the basis of Balakovo NPP Living PSA level 1

The aim of this task was to revise, evaluate and identify all the changes to be made in the Living PSA model in order to develop the Risk Monitor model.

Regarding this task, Iberdrola developed and validated the PSA model to be used as an input to the Risk Monitoring tool. This PSA model was based on the amended Living PSA model developed by DoP for Balakovo NPP. The implementation and the training of AEP experts started after the “frozen” PSA electronic model was available.

The performed activities in this task were:

• Iberdrola developed the Risk Monitor Model for Balakovo NPP.
• Iberdrola verified and validated the Risk Monitor Model for Balakovo NPP.
• Following comments from AEP, the final model was developed and delivered at the end of this task.

The DoP performed the following specific work on the Task 4:

• delivered to the Consultant the additional information for the development of Risk Monitor model,
• Installation of the Risk Watcher code in the DoP and Balakovo NPP offices and training of this code by the member of DoP team;
• the members of DoP team received the “Risk Spectrum Risk Watcher user course” and “Training for converting living PSA model into Risk Monitor model course” organized by the Consultant and received the certificates;
• Consideration, discussion and agreement of the materials, designed by Consultant on Task 4;
• Consideration, discussion and agreement of the “Risk Monitor” model;
• Participation in meetings.

 

Task 5 Installation of Risk Monitoring toolbox at Balakovo NPP and Risk Monitor trial operation

Iberdrola provided the necessary technical arrangements and services needed for:

• Installation at both Balakovo NPP and DoP offices of a Risk Monitor toolbox using the Balakovo NPP PSA model developed.
• Validation of the Installed Risk Monitor toolbox outputs using well defined written Procedure.
• Supervision and assistance needed during the trial operation of the Risk Monitor tool box.

Iberdrola installed the risk monitor model at DoP offices during a workshop held in May 2010.

Iberdrola installed the risk monitor model at Balakovo NPP during the first week of July 2010 and issued a procedure to use the RiskWatcher model for trial operation.

A meeting took place in Balakovo NPP Training Center during the 14th and 15th of September 2010. The objective of the meeting was to present and clarify the problems, errors and possible improvements detected when using the RiskWatcher software and Balakovo risk plant model during the trial operation.

Iberdrola reviewed and revised RiskWatcher model based on the results from trial operation in November 2010.

The DoP performed the following work on the Task 5:

• Translate the “Development of Balakovo Risk Monitor model for Balakovo NPP” developed by Consultant into Russian;
• Translate the “Verification & validation for Balakovo risk monitor model” developed by Consultant into Russian;
• Translate the “Risk Monitor Procedure for trial operation” developed by Consultant into Russian;
• Translate the “Balakovo Risk Monitor Application Guideliness” developed by Consultant into Russian;
• Also all screens of the Risk Monitor, used in above enumerated materials have been translated into Russian;

All materials were sent on an e-mail to the Balakovo NPP in October 2010.

 

Task 6: Training of Russian experts in the development and use of risk monitoring Technology

The aim of this task was to prepare, arrange and perform a training of Russian experts in the development and use of risk monitoring Technology and to issue and deliver the appropriate training material in order to conduct this training.

The Consultant conducted training in the use of risk monitor technology which was tailored to the needs of the different risk monitoring technology users, as follows:

• Training for the DoP staff into techniques for converting Living PSA models into Risk Monitor ones.
• Training for General Risk Monitor users from Balakovo NPP.
• Training for plant maintenance planners from Balakovo NPP.
• Training for the Balakovo NPP main control room operators.
• Training for PSA experts from Balakovo NPP and DoP to maintain and update the Risk Monitor software models.

Iberdrola trained DoP staff into techniques for converting Living PSA into Risk Monitor.

Iberdrola also conducted training for DoP staff and General Risk Monitor Users in the use of risk monitor technology. This training was held during the workshop of May 2010 at AEP premises.

Iberdrola trained PSA experts from Balakovo and DoP to maintain, update and use risk monitor software models during the two training meetings held in July and September 2010.

Iberdrola conducted training of Balakovo personnel in the use of risk monitor technology in Balakovo NPP premises during the final training meeting held at Balakovo in November 2010.

DoP delivered the component, system and sub-system definition of the model translated into Russian language to Iberdrola. All training materials (including the presentation by IBERDOLA) were translated in Russian and send to Balakovo NPP in e-mail.

 

Task 7: Preparation of Final Report and other final communication actions

The Final Report was issued highlighting the achievements of the project.