U3.IA/03-2 Licensing support to Khmelnitsky PIP (ref AP 7.2.3.1)

UK/TS/31 was a 2+2 project, for support to the nuclear safety regulator of Ukraine (SNRCU) in the assessment of EU financed safety improvements within industrial project U1.04/03 "Upgrading of electrical equipment of reactor control and protection system and neutron flux monitoring equipment on Khmelnitsky NPP unit 1".

The equipment comprised the following three main subsystems:

• Digital Instrumentation and Control System of Emergency and Preliminary Protection System (DI&CS EPS-PPS);
• Neutron Flux Monitoring System (NFMS-IF);
• Digital Instrumentation and Control System of Automatic Reactor Power Controller, Unloading and Power Limitation System, Accelerated Preliminary Protection System (DI&CS ARPC-UPLS-APPS).

The project consisted of one task with 4 technical sub-tasks:

Task 1. Upgrading of electrical equipment of reactor control and protection system and neutron flux monitoring equipment on Khmelnitsky NPP unit 1.

Sub-Task 1.0. Review of Technical specifications for tendering

The EU TSO review of the Technical specifications resulted in a set of consolidated comments on the general quality of the submitted Technical Specifications and various technical topics. The general conclusion was that the Technical Specification was a good document and addressed most of the relevant requirements. However, several important points were noted.

The licensee agreed to amend the Technical Specification to take account of the EU TSO comments or to make additional information available at the Tender Clarification Meeting. In a few cases, the EU TSO accepted the explanation provided by the licensee.

Sub-Task 1.1. Decision on procurement technical specification,

The EU TSO review of the technical specifications of the three systems was based on a “themed” approach to considerations of I&C safety.

Conclusions and corresponding recommendations concerned the ‘fitness for purpose’ of the documentation and both general and specific ‘technical’ topics. The Beneficiary accepted these without comment.

Sub-Task 1.2. Decision on equipment mounting,

Based on the results of the EU TSO and SSTC reviews of the PSAR, it was agreed that the PSAR documentation contained significant shortfalls. The reviewers recommended that these shortfalls should be addressed and corrected within the Final Safety Analysis Report (FSAR), which is the subject of Task 1.3.

Sub-Task 1.3. Decision on commissioning,

Based on the results of the EU TSOs and SSTC reviews of the FSAR, it was agreed that the FSAR reports contained significant shortfalls. These shortfalls included non-compliance with western standards, poor quality, and most significantly a failure to demonstrate sufficient safety arguments. While the experts agreed that the system itself is most likely fit for purpose, the shortfalls in the production of the documents and the lack of safety demonstration resulted in the judgement that the FSARs could not be accepted.

Seven recommendations were made. The first two of which were to significantly revise and reissue the FSAR documents to western standards with individual comments raised in this report suitably addressed. Two further recommendations were aimed at the plant to review the systems and equipment remaining on the plant for suitability and to review detailed interactions between the existing plant and the new equipment. A further two recommendations were for SNRCU to consider bringing Ukrainian safety classifications in line with western standards for I&C and to produce regulatory documents for the detailed contents of SAR documents to be produced in line with western standards. A final recommendation suggested that those responsible for producing SAR documents receive suitable training to help improve document standards and quality.

Sub-Task 1.4. Assessment of “modernization of the AUU design operating mode for the reactor facility VVER-1000.

This sub-task was a reaction on an incident that occurred with the new digital control and protection system on 22 September 2007 at Khmelnitsky unit 2 related to the accelerated unit unloading (AUU), caused by an emergency trip of the oil pump of the turbine driven feedwater pump.

SSTC presented its analysis and the EU TSO concluded that this SSTC assessment had been undertaken in a professional manner.