scholarly journals Transient Diagnosis and Prognosis for Secondary System in Nuclear Power Plants

2016 ◽  
Vol 48 (5) ◽  
pp. 1184-1191 ◽  
Author(s):  
Sangjun Park ◽  
Jinkyun Park ◽  
Gyunyoung Heo
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Secondary System ◽  
Diagnosis And Prognosis

Fundamental Mechanisms of Component Degradation by Corrosion in Nuclear Power Plants of Russian Design

2008 ◽  
Author(s):  
G. Saji ◽  
V. A. Yurmanov ◽  
V. I. Baranenko ◽  
V. A. Fedorova ◽  
G. Karzov ◽  
...  
Keyword(s):  
Power Systems ◽  
Water Chemistry ◽  
Steam Generator ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Electrochemical Characteristics ◽  
Secondary System ◽  
Technological Basis ◽  
Hydrogen Water

By focusing on NPPs of Western design (e.g. PWR and BWR), the first author (G. Saji) has established that ‘long cell action’ corrosion plays a pivotal role in practically all unresolved corrosion issues for all types of nuclear power plants as presented in a series of papers already published (1–9). The authors believe that a similar study of NPPs of Russian design, with their unique scientific and technological basis compared to Western plants, are important to illustrate that this mechanism can occur even with different materials, welding technology or operation (e.g. water chemistry control). Among all the differences, it is important to note that PWSCC per se does not seem to be occurring in VVER plants, although no specific reason has yet to be identified. In this paper, a detailed electrochemical assessment is first made on the behavior of ammonia-potassium water chemistry and structural materials at the normal operational temperature in the primary water of VVERs. The chemical and electrochemical characteristics of the ammonia in VVERS were found to be significantly different from those of PWRs which use the hydrogen water chemistry. However, the water chemistry of RBMK is not fundamentally different from that of the Western BWR and therefore the previous studies on SCC of BWRs are generally applicable. On the bases of these studies, various corrosion issues commonly experienced in NPPs of Russian design (VVER and RBMK) are briefly reviewed. They include: (i) pitting corrosion in un-clad VVER-440 RV; (ii) corrosion cracking at the transition welding joints of RV nozzles and piping; (iii) corrosion issues in PGV-440 steam generator collectors; (iv) steam generator tube and collector corrosion; (v) IGSCC in RBMK with austenitic steel piping; (vi) FAC (E-C) in the secondary system of VVERs; and (vii) Anomalous corrosion products sedimentation in the core region in some VVERs. Since the long cell action hypothesis does not seem to contradict the various corrosion activities being experienced in NPPs of Russian design, the first author invites further study on the potential involvement of this mechanism since this hypothesis provides new insight into many of the unresolved corrosion issues. More specifically, the VVERs’ ammonia-potassium water chemistry has theoretically been identified as playing a key role in the prevention of PWSCC, which is one of the most troublesome mechanism of corrosion degradation in many Western PWRs. In view of this significance, the authors proposed an urgent international joint initiative to prove or disprove this mechanism’s existence in nuclear power systems.

scholarly journals Prognostic and Health Management of Active Assets in Nuclear Power Plants

2020 ◽  
Vol 6 (3) ◽  
Author(s):  
Vivek Agarwal ◽  
Nancy Lybeck ◽  
Binh T. Pham ◽  
Richard Rusaw ◽  
Randall Bickford
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Health Management ◽  
National Laboratory ◽  
Remaining Useful Life ◽  
Prognostic Models ◽  
Idaho National Laboratory ◽  
Diagnosis And Prognosis ◽  
Prognostic And Health Management

This paper presents the development of diagnostic and prognostic capabilities for active assets in nuclear power plants (NPPs). The research was performed under the Advanced Instrumentation, Information, and Control Technologies Pathway of the Light Water Reactor Sustainability Program. Idaho National Laboratory researched, developed, implemented, and demonstrated diagnostic and prognostic models for generator step-up transformers (GSUs). The Fleet-Wide Prognostic and Health Management (FW-PHM) Suite software developed by the Electric Power Research Institute was used to perform diagnosis and prognosis. As part of the research activity, Idaho National Laboratory implemented 22 GSU diagnostic models in the Asset Fault Signature Database and two wellestablished GSU prognostic models for the paper winding insulation in the Remaining Useful Life Database of the FW-PHM Suite. The implemented models along with a simulated fault data stream were used to evaluate the diagnostic and prognostic capabilities of the FW-PHM Suite. Knowledge of the operating condition of plant asset gained from diagnosis and prognosis is critical for the safe, productive, and economical long-term operation of the current fleet of NPPs. This research addresses some of the gaps in the current state of technology development and enables effective application of diagnostics and prognostics to nuclear plant assets.

The Comprehensive Discussion of the Pipe Wall Thinning of Secondary System in BWR and PWR Nuclear Power Plants

2006 ◽  
Author(s):  
Taku Ohira ◽  
Tomohiko Hoshino
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Single Phase ◽  
Pipe Wall ◽  
Secondary System ◽  
Power Company ◽  
Wall Thinning ◽  
Secondary Systems ◽  
Pipe Bending

The behaviors of pipe wall thinning of secondary systems in The Japan Atomic Power Company (JAPC)’s BWR and PWR nuclear power plants were compared in this paper, to discuss the effects of respective factors contributing to corrosion protection of pipe. The rates of pipe wall thinning in single-phase flow environment, in both BWR and PWR, depend on temperature. Nevertheless, the rate of pipe wall thinning in PWR is more than that in BWR. The rates of pipe wall thinning at elbow of pipe, bending of pipe, straight run of pipe and reducer areas are mutually different, although they are located in the same line. Especially, the rates of pipe wall thinning at elbows of pipes, bendings of pipes, straight runs of pipes and reducers, which are located closely downstreams of the pumps discharge nozzles, elbows, orifices or bent pipes, depend on not the temperature but the pipe configuration.

scholarly journals Data pre-processing methods for NPP equipment diagnostics algorithms: an overview

2021 ◽  
Vol 7 (2) ◽  
pp. 111-125
Author(s):  
Iurii D. Katser ◽  
Vyacheslav O. Kozitsin ◽  
Ivan V. Maksimov ◽  
Denis A. Larionov ◽  
Konstantin I. Kotsoev
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Diagnostic Features ◽  
Processing Methods ◽  
Efficient Operation ◽  
Advantages And Disadvantages ◽  
Diagnosis And Prognosis ◽  
Processing Techniques ◽  
Source Signals

The main tasks of diagnostics at nuclear power plants are detection, localization, diagnosis, and prognosis of the development of malfunctions. Analytical algorithms of varying degrees of complexity are used to solve these tasks. Many of these algorithms require pre-processed input data for high-quality and efficient operation. The pre-processing stage can help to reduce the volume of the analyzed data, generate additional informative diagnostic features, find complex dependencies and hidden patterns, discard uninformative source signals and remove noise. Finally, it can produce an improvement in detection, localization and prognosis quality. This overview briefly describes the data collected at nuclear power plants and provides methods for their preliminary processing. The pre-processing techniques are systematized according to the tasks performed. Their advantages and disadvantages are presented and the requirements for the initial raw data are considered. The references include both fundamental scientific works and applied industrial research on the methods applied. The paper also indicates the mechanisms for applying the methods of signal pre-processing in real-time. The overview of the data pre-processing methods in application to nuclear power plants is obtained, their classification and characteristics are given, and the comparative analysis of the methods is presented.

Work structure in nuclear power plants

1983 ◽  
Author(s):  
Marjorie B. Bauman ◽  
Richard F. Pain ◽  
Harold P. Van Cott ◽  
Margery K. Davidson
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Work Structure

Life Extension of Nuclear Power Plants: World Situation and the USA Case

2010 ◽  
pp. 50-56 ◽  
Author(s):  
Pablo T. León ◽  
Loreto Cuesta ◽  
Eduardo Serra ◽  
Luis Yagüe
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Life Extension ◽  
The Usa
Sign in / Sign up

Export Citation Format

Share Document