1/3D modeling of the core coolant circuit of a PHWR nuclear power plant

2015 ◽  
Vol 83 ◽  
pp. 386-397 ◽  
Author(s):  
Santiago Corzo ◽  
Damian Ramajo ◽  
Norberto Nigro
2018 ◽  
Vol 20 (26) ◽  
pp. 18056-18065 ◽  
Author(s):  
Pierre-Arnaud Artola ◽  
Bernard Rousseau ◽  
Carine Clavaguéra ◽  
Marion Roy ◽  
Dominique You ◽  
...  

We show that molecular simulations are able to describe iron(ii) complexation by polyacrylic acid, thus preventing oxide precipitation in the secondary coolant circuit of nuclear power plant. Complexation is favoured with increasing polymer chain length.


1985 ◽  
Vol 1 (S1) ◽  
pp. 401-404
Author(s):  
Donald Reid

At 0400 hours on Wednesday, March 28, 1979, an extremely small and initially thought unimportant malfunction occurred at the nuclear power plant at Three Mile Island (TMI). Within a short period of time, that malfunction would turn into an event of momentous impact with repercussions felt over most of the world. The events of that malfunction would cause TMI to be labelled as the worst commercial nuclear incident in history and transform it into the nuclear test tube of the universe. What really happened at Three Mile Island? Thirty-six seconds after 0400 hours, several water pumps stopped functioning in the unit 2 nuclear power plant. In the minutes, hours and days that followed, a series of events—compounded by equipment failure, inappropriate procedures and human errors—escalated into the worst crisis yet experienced by the nation's nuclear power industry. This resulted in the loss of reactor coolant, overheating of the core, damage to the fuel (but probably no melting) and release outside the plant of radioactive gases. Hydrogen has was formed, primarily by the reaction between the zirconium casing that holds the radioactive fuel and steam. There, however, was no danger of the bubble inside the reactor vessel exploding, because of the absence of oxygen within the reactor.


2018 ◽  
Vol 1 (6) ◽  
pp. 177-184
Author(s):  
Son An Nguyen ◽  
Nguyen Trung Tran

In order to operate a nuclear power plant, ensuring safety is the most important factor. The function of safety rods are to shut down the reactor in case of emergency. The purpose of this paper to show the result of research and determine the value of safety rods SA, SB. Determination of the Boron concentration corresponding to each group of safety rods of OPR1000 nuclear reactor ensures the safely in the whole operation process. Experimental simulation is carried out in the system simulating core reactor OP1R1000 (CoSi OPR1000). The expermental result corresponds with the theoretic calculated result of Sa and Sb with 1500 pcm, 4000 pcm. The concentrations of Boron appropriately are 134 ppm and 284 ppm, respectively.


Author(s):  
Toru Yamamoto

Based on radioactivity measurement of soil samples in the site of Fukushima Dai-Ichi Nuclear Power Station, radioactivity of Sr, Nb, Mo, Tc, Ru, Ag, Te, I, Cs, Ba, La, Pu, Am, and Cm isotopes were compiled as radioactivity ratios to 137Cs. By exponentially fitting or averaging, the radioactivity ratios at the core shutdown were estimated. They were divided by those of the fuel of the core at the shutdown to obtain a deposited radioactivity fractions of the nuclides as relative values to 137Cs, which also correspond to deposition fractions of the elements as relative values to Cs. They were estimated to be orders of 10−4 to 10−3 for Sr, 10−4 for Nb, 10−2 to 10−1 for Mo, 10−1 for Ag, 10−1 to 100 for Te, 100 for I, 10−3 for Ba, 10−6 to 10−5 for Pu, 10−6 to 10−5 for Am, and 10−6 for Cm. The observed radioactivity ratios to 137Cs were compared with those obtained by severe accident analysis to assess the validation of the analysis.


Kerntechnik ◽  
2019 ◽  
Vol 84 (3) ◽  
pp. 161-168
Author(s):  
H.-T. Lin ◽  
J.-R. Wang ◽  
H.-C. Chen ◽  
J.-H. Yang ◽  
S.-W. Chen ◽  
...  

2013 ◽  
Vol 373-375 ◽  
pp. 1703-1709
Author(s):  
Jin Jin Xu ◽  
Zhong Wen ◽  
Kai Feng Zhang ◽  
Zheng Gang Guan ◽  
Chen Ye

In order to improve the effect of refueling training in nuclear power plant, the simulation system of refueling machine was designed and developed, combining the virtual reality technology with a real control console. The 3D virtual refueling environment of nuclear power plant was established by 3D modeling. Signals from touch screen and console are gathered by PLC and transmitted to PC graphics workstation, control the motion of virtual refueling machine, which realize the refueling operation simulation. The operation in failure modes was also realized in the system through the programming of failure database. The results show that the system runs normally and can simulate refueling operation in normal and abnormal modes, the training of refueling personnel is implemented effectively.


Author(s):  
Sheng Zhu

Double ended break of direct vessel injection line (DEDVI) is the most typical small-break lost of coolant accident (LOCA) in AP 1000 nuclear power plant. This study simulated the DEDVI (without actuation of automatic depressurization system 1–3 stage valves, accumulators and passive residual heat removal heat exchanger) beyond design basis accident (BDBA) to validate the safety capability of AP1000 under such conditions. The results show that the core will be uncovered for about 863 seconds and then recovered by water after gravity injection from IRWST into the pressure vessel. The peak cladding temperature (PCT) goes up to 838.08°C, much lower than the limiting value 1204°C. This study confirms that in the DEDVI beyond design basis accident, the passive core cooling system (PXS) can effectually cool the core and preserve it integrate, and ensure the safety of AP 1000 nuclear power plant.


Author(s):  
Lihua Wang ◽  
Qingxiang Yang ◽  
Ping Yang ◽  
Jiazheng Liu ◽  
Libing Zhu ◽  
...  

Due to debris in the coolant against clad, fuel clad wear, fuel handling fault and so on, fuel rods maybe be damaged during the operation of nuclear power plants, in order that the fuel assemblies with damaged fuel rods are discharged before scheduled. If the damaged fuel assemblies are not reloaded into the core of the nuclear power plant, the fuel utilization decreases and the economy of the nuclear power plant is partly lost. For retrieving the loss of the economy, the damaged fuel assemblies can be repaired by replacing damaged fuel rods with dummy rods which don’t include fissile nuclides. Then, the repaired fuel assemblies can be reloaded into the core. As the repaired fuel assemblies are different with the normal fuel assemblies, especially the number of the damaged fuel rods is considerable, a whole quantitative analysis is very necessary to evaluate the effects from the reuse of the repaired fuel assemblies. In this paper, a full scope evaluation of reload design are performed including nuclear design, fuel design, thermal hydraulic design and safety evaluation, and some necessary improvements are done for the software system, design methods and progress which have been used in the normal reload design. As results, an integrated evaluation technique is developed to evaluate the feasibility and safety of reusing the repaired fuel assemblies, and the key effects due to the reuse of the repaired fuel assemblies are extracted, and the different effects are studied for the different materials of the dummy rods which can be used to conduct how to choose the proper material of dummy rods. In addition, this technique has been successfully applied in the engineering and the loss of economy due to the damage of fuel assemblies was retrieved partly. Therefore, the integrated evaluation technique has also important directive to other nuclear power plants if the repaired fuel assemblies are planned to reuse.


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