Loss of Feed Water Accident in an Integral Pressurized Water Reactor (IPWR)

2010 ◽  
Vol 171-172 ◽  
pp. 379-384
Author(s):  
Khan Salah Ud Din ◽  
Min Jun Peng ◽  
Muhammad Zubair

In this paper research has been carried out on Loss of Feed Water Accident (LOFW) scenario of the Integral Pressurized Water Reactor ( IPWR) under two circumstances by the use of thermal hydraulic system code i.e Relap5/Mod3.4. In the first one, Passive Residual Heat Removal System (PRHRS) which is designed to absorb core residual heat in case of transient conditions is included which has the function of operating under the accident vulnerabilities. Concerning with the second case i.e without the use of PRHRS rather a tank of water which has the capacity of about 8% of the total feed water supply and is operated under accident scenario is considered. Taken into account these conditions,first the nodalization diagram of the two cases have been figured out then according to the LOFW accident time event scenario use the Relap5 code to simulate the accident. Finally the graphical explanation (separately) of the two cases with graphical approach as well as the conclusion is given at the end.

Author(s):  
Liguo Jiang ◽  
Minjun Peng ◽  
Jiange Liu

One of more frequent events in the Pressurized Water Reactor (PWR) is Steam Generator Tube Rupture (SGTR) accident, which is among the main accidents in the field of nuclear safety. This paper studies the SGTR event in the Multi-application Integrated Pressurized Water Reactor (IPWR) using the best-estimate thermal-hydraulic code RELAP5/MOD3.4. In the reactor of IPWR, several Once-Through Steam Generator (OTSG) cassettes are used and located between the core support and the pressure vessel. The tube rupture location is on the top of the tube sheet of a steam generator. Three different tube rupture modeling methods and several different subcooled discharge coefficients in the critical flow model are considered and compared. In the safety analysis, high pressure safety injection system, core makeup system and Passive Residual Heat Removal System (PRHRS) that would affect the accident consequences are considered.


2009 ◽  
Vol 2009 ◽  
pp. 1-12 ◽  
Author(s):  
Junli Gou ◽  
Suizheng Qiu ◽  
Guanghui Su ◽  
Douna Jia

A theoretical investigation on the thermal hydraulic characteristics of a new type of passive residual heat removal system (PRHRS), which is connected to the reactor coolant system via the secondary side of the steam generator, for an integral pressurized water reactor is presented in this paper. Three-interknited natural circulation loops are adopted by this PRHRS to remove the residual heat of the reactor core after a reactor trip. Based on the one-dimensional model and a simulation code (SCPRHRS), the transient behaviors of the PRHRS as well as the effects of the height difference between the steam generator and the heat exchanger and the heat transfer area of the heat exchanger are studied in detail. Through the calculation analysis, it is found that the calculated parameter variation trends are reasonable. The higher height difference between the steam generator and the residual heat exchanger and the larger heat transfer area of the residual heat exchanger are favorable to the passive residual heat removal system.


Author(s):  
Shoubao Dai ◽  
Minjun Peng ◽  
Jiange Liu

The characteristics of passive safety systems for an integral pressurized water reactor (IPWR) are quite different from the general reactor because of special configuration and dangerous run environment. Passive residual heat removal system (PRHRS) for the IPWR with three-interknited natural coolant circulation loops, safely remove the core decay heat to the ultimate heat sink. Using RELAP5/MOD3.4 code to simulate this system during the reactor trip, analyses the steady-state and transient-state thermohydraulic behaviors for the IPWR and its PRHRS, and the effects of design parameters on the system. it is found that on the initial period of reactor trip, due to the establishment of the natural circulation in three loops uncompleted, the secondary loop pressure have the peak value. Through analyzing the effects of design parameters on the system, the PRHRS are optimized. The results show that the larger the residual heat exchanger (RHE) heat transfer area and the higher the height difference between the steam generator and the residual heat exchanger, the easier the establishment of the natural circulation in the third loop, but which make the peak value of the secondary loop pressure higher. According to set the compensating water tank, which is parallel connected to the RHE, can lighten the higher the peak value of the secondary loop pressure, and optimize the design of PRHRS.


Author(s):  
Jeffrey A. Brown ◽  
Robert D. Blevins ◽  
H. Joseph Fernando

This paper presents the results of a scaled aero acoustic test that modeled a side branch resonance observed in the residual heat removal suction line of a large pressurized water reactor. Resolution of the acoustic resonance was sought by detuning the eddy shedding frequency from the fundamental side branch acoustic mode. The specific physical modifications and their ability to detune the coupled system are presented.


Author(s):  
Yang Liu ◽  
Haijun Jia ◽  
Li Weihua

Passive decay heat removal (PDHR) system is important to the safety of integral pressurized water reactor (IPWR). In small break LOCA sequence, the depressurization of the reactor pressure vessel (RPV) is achieved by the PDHR that remove the decay heat by condensing steam directly through the SGs inside the RPV at high pressure. The non-condensable gases in the RPV significantly weaken the heat transfer capability of PDHR. This paper focus on the non-condensable gas effects in passive decay heat removal system at high pressure. A series of experiments are conducted in the Institute of Nuclear and New Energy Technology test facility with various heating power and non-condensable gas volume ratio. The results are significant to the optimizing design of the PDHR and the safety operation of the IPWR.


Author(s):  
Xuhua Ye ◽  
Minjun Peng ◽  
Jiange Liu

An investigation on the thermal hydraulic characteristics of the passive residual heat removal system (PRHRS) which is used in an integral pressurized water reactor (INSURE-100) is presented in this paper. The main components of primary coolant system are enclosed in reactor vessel. Primary fluid flow circle is natural circulation. The PRHRS can remove the energy from the primary side as long as the residual heat exchanger (RHE) is submerged in the emergency cooldown tank (ECT). The parameter study is performed by considering the effects of an effective height between the steam generators and the RHE and a valve actuation time, which are useful for the design of the PRHRS. The mass flow in the PRHRS has been affected by the height difference between the steam generators and the RHE. The pressure peak of the primary side and PRHRS has been affected by the valve action time.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Zhuo Wenbin ◽  
Huang Yanping ◽  
Xiao Zejun ◽  
Peng Chuanxin ◽  
Lu Sansan

Passive residual heat removal system (PRHRS) for the secondary loop is one of the important features for Chinese advance pressurized water reactor (CAPWR). To prove the safety characteristics of CAPWR, serials of experiments have been done on special designed PRHRS test facility in the former stage. The test facility was built up following the scaling laws to preserve the similarity to CAPWR. A total of more than 300 tests have been performed on the test facility, including 90% steady state cases and 10% transient cases. A semiempirical model was generated for passive heat removal functions based on the experimental results of steady state cases. The dynamic capability characteristics and reliability of passive safety system for CAPWR were evidently proved by transient cases. A new simulation code, MISAP2.0, has been developed and calibrated by experimental results. It will be applied in future design evaluation and optimization works.


Author(s):  
Xiao Yuan ◽  
Minjun Peng ◽  
Genglei Xia

The passive safety systems employed in the design of pressurized water reactor (PWR) can accomplish the inherent safety functions and mitigate the consequences of the postulated accidents. In this paper, a passive residual heat removal system (PRHRs) is designed for a certain nuclear power plant. The RELAP5/MOD3.4 code was used to analyze the operation characteristics of the PRHRs. It shows the PRHRs could remove the decay heat from the primary loop effectively, and the single-phase and two-phase natural circulations could respectively establish in the primary circuit and the PRHRs circuit.


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