T. V. Pyrohov, V. V. Inyushev, V. O. Kurov, A. S. Koliadiuk
SE “State Scientific Engineering Center for Control System and Emergency Response”, 64/56, Heroiv Stalinhrada ave, Kyiv, 04213, Ukraine
The design strength of 61409 RR1 emergency cooling of the heat exchanger 08.8111.335 SB, as the main design and factory document governing the safe operation of the heat exchanger during its operation in such modes as normal operating conditions, hydraulic tests and seismic loads under time of normal operating conditions is considered and analyzed in the article. The purpose of the work is to analyze the document 61409 RR1 for compliance with current standards of Ukraine in nuclear energy.
It is shown that the design strength calculation 61409 RR1 doesn’t comply with the requirements of current regulatory documents.
The document does not present the results of the calculation of static and cyclic strength for the elements of flange joints and studs in particular. However, the results of the calculations of the studs, given in the section “Structural calculation” demonstrate the excess of the allowable values of stresses in the group of membrane stresses.
Since 2016, a new normative document NP 306.2.2082016 has been in force in Ukraine, which replaced the norms of PNAE G-5-006-87. The new normative document states that one of the combinations of loads, when considering seismic effects, is violation of normal operating conditions and maximum considered earthquake. Therefore, document 61409 PP1 can not be used as a technical document regulating the safe operation of the emergency cooling heat exchanger 08.8111.335 SB during seismic impacts in works related to the justification of safe operation of equipment of existing NPPs of Ukraine.
Based on the above, it is recommended to perform additional calculations on the strength of the emergency heat exchanger 08.8111.335 SB, which will also take into account the calculations of the elements of flange connections, as well as a combination of violations of normal loads and the maximum predicted earthquake, and generally meet current regulations of Ukraine in nuclear energy.
Keywords: emergency cooling heat exchanger, lifetime extension, calculational substantiation of safe operation, stiffness characteristics, technical condition assessment.
1. NP 306.099-2004. General requirements for the extension of the NPP unit’s operation beyond the design lifetime based on the results of periodic safety review. Kyiv: State Committee for Nuclear Regulation of Ukraine, 2004, 16 p. (in Ukr.)
2. 61409 PPI. Emergency cooling heat exchanger. Strength calculation. Moscow: VNIIAM, 1973.
3. PNAE G-7-002-86. Standards for strength calculation of equipment and pipelines of nuclear power plants [introduced with changes on 07/01/1987]. Moscow: Energoat-omizdat, 1989, 525 p. (in Russ.)
4. NP 306.2.208-2016. Requirements for seismic-resistant design and seismic safety assessment of nuclear power plant
units. Kyiv: State Committee for Nuclear Regulation of Ukraine, 2016, 37 p. (in Ukr.)
5. PL-D.0.03.126-10. Regulation of the procedure for extending the life of equipment of systems important to safety. Kyiv: NNEGC “Energoatom”, 2010, 34 p. (in Russ.)
6. Standards for strength analysis of reactors elements, steam generators, vessels and pipelines of nuclear power plants, experimental and research nuclear reactors and installations. Moscow: Metallurgiya, 1973, 408 p. (in Russ.)
7. TU 108.1089-82. Emergency cooling heat exchanger. Specifications. 1986. (in Russ.)
8. 088111.335 IE. Emergency cooling heat exchanger. Instruction manual. (in Russ.)
9. PNAE G-7-008-89. Rules for Arrangement and Safe Operation of Equipment and Piping of Nuclear Power Installations. Gosatomnadzor, 1990. (in Russ.)
10. Energy strategy of Ukraine for the period up to 2035 “Security, energy efficiency, competitiveness”. Approved by the Order of the Cabinet of Ministers dated 18.08.2017 no. 605-p, 66 p. (in Ukr.)
If the article is accepted for publication in the journal «Industrial Heat Engineering» the author must sign an agreement on transfer of copyright. The agreement is sent to the postal (original) or e-mail address (scanned copy) of the journal editions.
Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License International CC-BY that allows others to share the work with an acknowledgement of the work’s authorship and initial publication in this journal.