FOR THE INTRODUCTION OF FUEL PRODUCED BY WESTINGHOUSE SRPA «IMPULSE» MODERNIZED IN-CORE MONITORING SYSTEM AT POWER UNIT № 3 RIVNE NPP

During PPM-2022 at the Unit № 3 of the Rivne NPP, the next step was taken to replace fuel produced by TVEL (RF) with fuel produced by Westinghouse. This step is a continuation of a multi-year program that is gradually being implemented by NNEGC «Energoatom» at Ukrainian NPPs. The core topic of this program is that the national nuclear operator managed to integrate the efforts of the best specialists of the nuclear industry complex of Ukraine and the United States to meet this challenge in the most reliable, technically viable and economically cost-effective way.

One of the best examples of solving this problem is the integration of the domestic in-core monitoring system SVRK produced by SRPA «Impulse» with the software for neutron-physical calculations «Beacon», the developer of which is Westinghouse, which is also a developer and manufacturer of fuel. This approach made it possible to combine the knowledge and experience of domestic specialists in terms of thermal-hydraulic calculations and core monitoring systems for VVER-type reactors with Westinghouse's experience in calculating cores with different types of fuel and geometric parameters. From the beginning, NNEGC «Energoatom», Westinghouse and SRPA «Impulse» introduced a systematic approach to guarantee the result, which consisted of the following steps:

• testing of the «Beacon» software with hardware produced by SRPA «Impulse» at the Westinghouse site;
• finalize and implementation of new calculated and service functions of the SVRK;
• multi-stage successive approbation at NPP Units and licensing at the State Nuclear Regulatory Inspectorate of Ukraine (SNRIU);
• making it possible for a two-stage modernization of the SVRK (separately for the upper and lower levels) with a view to optimize current costs.

Outcome of these persistent efforts was the introduction of mixed loads at the Units of the South-Ukraine NPP, Zaporizhie NPP, and now at the Unit № 3 Rivne NPP. Taking into account the considerable positive experience of the long-term joint work of NNEGC «Energoatom», Westinghouse and SRPA «Impulse» on the modernization of the SVRK to control mixed fuel loads, the next steps during 2023-2025 may be similar projects for Units RNPP-4, KhNPP-1, 2 with the VVER-1000 reactors, and also RAES-1, 2 with the VVER-440 reactors.