Determination of control rod positions during fuel life-cycle using fixed in-core Self-Powered Neutron Detectors of Tehran Research Reactor

The value of the reactor thermal power (RTP) is used in the VVER-1000 control systems in most algorithms for generation of control, blocking and protection signals. Besides, the technical and economic indicators of the power unit are determined by this parameter. Plans to increase VVER‑1000 RTP to 101.5%, and later to 104-107% of the nominal require additional justification of the accuracy of the RTP determination. Therefore, the task of increasing the accuracy of RTP determination is important. The paper describes the ways to improve the accuracy of weighted mean thermal power (WMTP) determination by selecting the optimal weight coefficient (that subsequently is used for WMTP determination) of each of the methods of RTP determination, namely: by thermotechnical parameters of the primary and secondary sides by neutron flux in the in-core monitoring system (ICMS) and in the neutron flux control equipment (NFCE). Another possibility of increasing the accuracy of WMTP determination, namely by increasing the number of methods of RTP determination, is also considered in the paper. The analysis of changes in the background signals of self-powered neutron detectors (SPNDs) during the VVER-1000 fuel campaigns shows the fundamental possibility of using the total background signal as a separate and independent method for RTP determination. The paper presents the results of the calculation of RTP determination error taking into account the coefficients of the components of the total RTP determination error: systematic, dynamic and random errors, which must be determined during the commissioning phase. The results of reduction of the error of WMTP determination in case of application of the additional method of RTP determination based on background signals of the SPNDs are presented. Theoretically, possible minimum values of the WMTP determination error are given depending on the values of the error of the RTP determination by separate methods.

Download Full-text

Inspection of domestic nuclear fuel rods using neutron radiography at the Tehran Research Reactor

Materials Testing ◽

10.3139/120.110923 ◽

2016 ◽

Vol 58 (9) ◽

pp. 763-766 ◽

Cited By ~ 2

Author(s):

Mohammad Hosein Choopan Dastjerdi ◽

Hossein Khalafi ◽

Yaser Kasesaz ◽

Amir Movafeghi

Keyword(s):

Nuclear Fuel ◽

Research Reactor ◽

Neutron Radiography ◽

Fuel Rods ◽

Tehran Research Reactor ◽

Nuclear Fuel Rods

Download Full-text

USA–Iran, 2009–2010

10.1093/oso/9780199696475.003.0009 ◽

2018 ◽

Author(s):

Nicholas J. Wheeler

Keyword(s):

Nuclear Fuel ◽

Research Reactor ◽

Interpersonal Trust ◽

Obama Administration ◽

Face To Face ◽

Tehran Research Reactor

This chapter examines the attempts by the first Obama Administration to reach out to Iran in an effort to build trust. It traces the failure of Obama’s diplomatic efforts to secure any reciprocation from Iranian leaders. The lack of reciprocation shows the problem of accurate signal interpretation when there is no trust. It focuses on the negotiations in 2009–10 over limiting Iran’s supply of nuclear fuel in return for refuelling the Tehran Research Reactor. The chapter argues these negotiations failed because of the lack of trust. What makes this case so important is that there was no face-to-face interaction, which this book argues is critical to the development of interpersonal trust and accurate signal interpretation.

Download Full-text