Calculation and Analysis of Steam Hammer in Main Steam Pipe in HPR1000

2020 ◽  
Author(s):  
Pei Yu ◽  
Jiaming Wang ◽  
Huiyun Ma ◽  
Haifeng Gu ◽  
Changqi Yan
Keyword(s):  
The Other ◽  
Closing Time ◽  
Straight Pipe ◽  
Pipe System ◽  
Pipe Section ◽  
Steam Pipe ◽  
Steam Header ◽  
Main Steam ◽  
Simplified Calculation ◽  
Steam System

Abstract The steam hammer pressure is solved though the simplified calculation. PIPENET software is applied to model the nuclear island main steam system between the steam generator and the main steam header in HPR 1000. The transient module is used to simulate the occurrence and attenuation process of steam hammer. The maximum steam hammer pressure, the maximum steam hammer stress in the pipe system, when and where the load occurs are given. The influence of the straight pipe section length and valve closing time on the steam hammer effect is analyzed. With the other conditions unchanged, the steam hammer energy decreases as the straight pipe section shortens, or the valve closing time extends.

Failure of a Seamless 2-1/4Cr-1Mo Hot-Reheat Pipe Bend: Acoustic Emission Testing and Fitness for Service of Other Steam Pipe Bends

2010 ◽  
Author(s):  
G. A. White ◽  
M. T. Klug ◽  
J. A. Gorman ◽  
J. M. Rodgers ◽  
R. Griffin
Keyword(s):  
Acoustic Emission ◽  
Creep Crack Growth ◽  
Companion Paper ◽  
The Other ◽  
Grain Structure ◽  
Creep Ductility ◽  
Pipe Bend ◽  
Steam Pipe ◽  
Main Steam ◽  
Failure Evaluation

In April 2008, after 113,230 hours of operation at Belledune Generating Station Unit #2 in New Brunswick, Canada, a seamless ASME SA-335 grade P22 (2 1/4Cr-1Mo) steel hot-reheat steam pipe was found to be cracked longitudinally through the presence of a steam leak. The crack, shown in Figure 1, was about 760 mm (30 inches) long and on the extrados of a long-radius bend. No catastrophic rupture occurred of the pipe, which had an outside diameter of about 950 mm (37.5 in.). The particular bend in question was made by hot bending after furnace heating and slowly cooling in air. Prior to the unit being returned to operation, the cracked bend was replaced with a newly fabricated bend. As reported in a companion paper [1], a detailed root cause failure evaluation indicated that overheating the pipe in the furnace at the time the bending was performed produced an extremely large grain structure and was likely a key factor in the creep cracking degradation observed. Further, the failure evaluation indicated exceptionally low creep ductility for the material in the failed bend. Metallurgical examinations of the other 16 hot-reheat and main steam pipe bends in the unit showed a range of atypically large grain sizes, although not as large as for the failed bend. This paper describes the methods and findings of a study to assess the suitability for continued service of the other primary steam pipe bends at the station; and to determine the appropriate actions, such as additional inspections, for maintaining safe operation of these piping systems. This study included detailed assessments of the hot operating stresses in the bends (including those due to pipe moment loads and ovalization effects), creep crack growth assessments using the EPRI BLESS software, and acoustic emission (AE) testing on four bends remaining in service.

scholarly journals Analysis of abnormal expansion of pipe system and optimization of structural stress in 350MW unit

2021 ◽  
Vol 261 ◽  
pp. 02073
Author(s):  
Xin Liu ◽  
Yanming Zhang ◽  
Qun Liu ◽  
Xu Sun ◽  
Yu Wang ◽  
...  
Keyword(s):  
System Support ◽  
Load Testing ◽  
Pipe System ◽  
Overall Design ◽  
Calculation Results ◽  
Load Tests ◽  
Steam Pipe ◽  
Main Steam ◽  
Elevation Measurement ◽  
State Stress

A 350MW power plant main steam and reheat hot steam pipe subsidence occurred in part of the pipe section, through field inspection, calculation and checking analysis, combined with pipeline support and hanger adjustment, load testing and elevation measurement and other means, the settlement of the pipe system to optimize the overall stress state of the pipe system. Through the thermal displacement of the pipe system support lifting point, the selection and calculation of the pipe system support hanger and the overall design state stress check of the pipe system, the design state is basically consistent with the check state. Through to the key node load tests have shown that small spring hanger selection is the primary cause of section settling, combined with the spring adjustment space and calculation results are part of the hanger. Finally, the settlement of pipeline is realized, main steam pipe at the same time a stress and secondary stress were achieved about 15% of the decline, piping stress has been further optimized.

Verification of creep analyzes of a steam pipe system, Swedish Energy Agency

Impact ◽  
2018 ◽  
Vol 2018 (1) ◽  
pp. 86-88
Author(s):  
Jan Storesund ◽  
Rikard Norling
Keyword(s):  
Energy Agency ◽  
Pipe System ◽  
Steam Pipe

scholarly journals On the volatility of sensex

2012 ◽  
Vol 1 (1) ◽  
pp. 10-22
Author(s):  
Nateson C ◽  
Suganya D
Keyword(s):  
Time Series ◽  
Time Series Data ◽  
The Other ◽  
Stock Index ◽  
Series Data ◽  
Closing Time ◽  
Market Activity ◽  
Year 2000 ◽  
Daily Returns

The present study seeks to analyse Volatility of popular stock index SENSEX. The present study is based on the closing time series data of SENSEX covering the period from 3rd January 2000, to 30th June 2011. The year 2008 has recorded higher Volatility compared to the other years of the study. Volatility fell in the year 2009 from the high of 2008. The years after were comparatively calmer. In the year 2000, the Volatility was higher signifying enhance market activity. The overall daily Volatility for SENSEX was approximately 1.70 % while the annualized value was approximately 25%-26%. Events Reported around Daily Returns in Excess of +/-5%have also been identified.

Musing on Unanswered Questions

2020 ◽  
pp. 1-20
Author(s):  
Meta Lee Van Sickle ◽  
Merrie Koester
Keyword(s):  
Learning Process ◽  
Grey Matter ◽  
Science Educator ◽  
The Other ◽  
Grant Writing ◽  
Habits Of Mind ◽  
Vocal Performance ◽  
Long Time ◽  
Teaching Learning ◽  
Steam System

Out of a conversation between two long-time colleagues—each a science educator and practicing artist—emerged the question, “What does it mean to STEAMify a lesson, and why would a teacher actually choose to do such a thing, other than, say, for-grant-writing-purposes?” Their science selves really liked the idea of a STEAM system, acted upon by forces, both from the outside and from within, and with energy flowing and cycling, all the while transforming grey matter in ways that sustained the teaching/learning process. When it came to their art; however, their dialogue followed pathways grooved by long years of practice and hard work in their respective fields. One author is a seasoned vocalist, trained in the nuances of both individual and group vocal performance as well as the attendant dimensions of music, its composition and phraseology. The other is a painter, poet, and novelist, shaping words, color, and line to tell stories and communicate ideas. What was significant to each was that their artistic habits of mind had shaped their axiology, transforming their ways teaching.

Musing on Unanswered Questions

2017 ◽  
pp. 1-20
Author(s):  
Meta Lee Van Sickle ◽  
Merrie Koester
Keyword(s):  
Learning Process ◽  
Grey Matter ◽  
Science Educator ◽  
The Other ◽  
Grant Writing ◽  
Habits Of Mind ◽  
Vocal Performance ◽  
Long Time ◽  
Teaching Learning ◽  
Steam System

Out of a conversation between two long-time colleagues—each a science educator and practicing artist, emerged the question, “What does it mean to STEAMify a lesson, and why would a teacher actually choose to do such a thing, other than, say, for-grant-writing-purposes? Their science selves really liked the idea of a STEAM system, acted upon by forces, both from the outside and from within, and with energy flowing and cycling, all the while transforming grey matter in ways that sustained the teaching/learning process. When it came to their art, however, their dialogue followed pathways grooved by long years of practice and hard work in their respective fields. One author is a seasoned vocalist, trained in the nuances of both individual and group vocal performance as well as the attendant dimensions of music, its composition and phraseology. The other is a painter, poet, and novelist, shaping words, color, and line to tell stories and communicate ideas. What was significant to each was that their artistic habits of mind had shaped their axiology, transforming their ways teaching.

Application of Earthquake Experience Data as Part of the Seismic Verification of Modified Main Steam Isolation Valve Leakage Pathway Piping

2004 ◽  
Author(s):  
Timothy M. Adams ◽  
Scott Quiggle
Keyword(s):  
Control Systems ◽  
Radioactive Iodine ◽  
Leakage Rate ◽  
Original Design ◽  
System A ◽  
Gas System ◽  
Group Report ◽  
Valve Leakage ◽  
Main Steam ◽  
Steam System

The Monticello Nuclear Generating Plant made modifications to the turbine island in 1998 to achieve a 5% power uprate. The radiological analysis conducted for power uprate took credit for deposition and holdup of radioactive iodine in the steam lines downstream of the Main Steam Isolation Valves (MSIV’s) and in the main condenser. The original design basis of certain main steam system piping, equipment, and components that comprise the MSIV Leakage Pathway was not in accordance with Seismic Category I requirements. As part of the original program seismic verification walkdowns were performed to demonstrate the main steam system piping, equipment, and components were seismically rugged. The walkdowns were done using the methodology suggested to seismically evaluate this pathway in the Boiling Water Reactor Owners’ Group report, entitled “BWROG Report of Increasing MSIV Leakage Rate Limits and Elimination of Leakage Control Systems”. In 2001, Monticello made significant changes to improve the performance of the plants hydrogen recombiner process. The hydrogen recombiners are part of the off gas system a portion of which was in the original MSIV Leakage Pathway. These modifications significantly redefined MSIV Leakage Pathway and required an updated assessment of the seismic ruggedness of piping and associated equipment in the MSIV Leakage Pathway. This paper describes the approach and methodology used to update and expand the seismic evaluations and seismic verification walkdowns. It also summarizes the results of these walkdowns and the steps necessary to demonstrate the seismic adequacy of the piping and equipment.

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