Analysis of Accumulation and Crystallization of Boric Acid in the Reactor Core during WWER Emergency Operation

2017 ◽  
Vol 743 ◽  
pp. 389-393 ◽  
Author(s):  
Andrei V. Morozov ◽  
Anna V. Pityk ◽  
Sergei V. Ragulin ◽  
Aleksandra S. Soshkina
Keyword(s):  
Boric Acid ◽  
Acid Concentration ◽  
Reactor Core ◽  
Emergency Operation ◽  
The Core ◽  
Acid Accumulation ◽  
Hand Calculation ◽  
New Generation ◽  
Boric Acid Concentration

The results of hand calculation of boric acid accumulation in the core in a new generation WWER-TOI reactor in case of LOCA are presented. Variants of reducing the H3BO3 concentration in the HA-3 system down to 1, 2, 4 and 8 g/kg are considered. The mass of boric acid deposits on the core internals depending on the value of boric acid concentration in the HA-3 system is determined. The obtained results allow concluding that the accumulation and crystallization of boric acid in the core is possible.

Execution of 18 Month Refueling Modification and Experience Feedback

2010 ◽  
Author(s):  
Guo-long Sheng ◽  
Yang Pu
Keyword(s):  
Boric Acid ◽  
Acid Concentration ◽  
Field Experience ◽  
Fuel Cycle ◽  
Technical Specification ◽  
Physical Experiment ◽  
Set Point ◽  
Nuclear Plants ◽  
Operation Procedure ◽  
Boric Acid Concentration

The article presents how to plan, organize, and put in practice of the 18-months fuel cycle project on the newly built up nuclear plants. Some problems related to the field experience of modification and the amelioration suggestions are also provided. It’s involved that operation procedure modification, operation technical specification modification, test period prolongation, set point adjustment, boric acid concentration adjustment, re-start physical experiment and so on.

Influence of boric acid concentration on silicon carbide morphology

1995 ◽  
Vol 14 (15) ◽  
pp. 1052-1054 ◽  
Author(s):  
LJ. S. čerović ◽  
S. K. Milonjić ◽  
N. M. Bibić
Keyword(s):  
Silicon Carbide ◽  
Boric Acid ◽  
Acid Concentration ◽  
Carbide Morphology ◽  
Boric Acid Concentration

scholarly journals Effects of Boric Acid Concentration and Shading on Growth, Leaf Physiology, and Anatomy of Guzmania

HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 618-621 ◽  
Author(s):  
C.Y. Kuo ◽  
D.M. Yeh
Keyword(s):  
Boric Acid ◽  
Acid Concentration ◽  
Leaf Growth ◽  
Dry Weight ◽  
Leaf Physiology ◽  
Half Strength ◽  
Leaf Necrosis ◽  
Induced Changes ◽  
Leaf Boron ◽  
Boric Acid Concentration

Guzmania lingulata (L.) Mez. `Cherry' were grown in coco chips and fertigated with half-strength Hoagland solution containing various concentrations of boric acid. Excessive boron induced changes in growth, relative chlorophyll content, and leaf anatomy were investigated. Plants treated with 5 mg·L–1 or higher boric acid concentration had reduced SPAD-502 readings and Fv/Fm values and increased leaf necrosis in the lower leaves. Boron was distributed unevenly within a leaf, with the maximum concentration in the leaf tip. Increased necrotic length and new leaves with necrosis were evident where average whole leaf boron concentration was higher than 170 μg·g–1 on dry weight basis. More leaf growth and higher transpiration or stomatal conductance were recorded in plants under 40% (average 676 μmol·m–2·s–1 PPF at noon) than 76% (average 270 μmol·m–2·s–1 PPF at noon) shade. Excessive boron was not found to affect epidermal cells or water storage tissue, but caused browning and shriveling of the chlorenchyma cells.

scholarly journals Estimation influence of boric acid drop entrainment to its accumulation in the VVER reactor in the case of accident

2018 ◽  
Vol 4 (1) ◽  
pp. 65-71
Author(s):  
Andrej V. Morozov ◽  
Anna V. Pityk ◽  
Sergej V. Ragulin ◽  
Azamat R. Sahipgareev ◽  
Aleksandra S. Soshkina ◽  
...  
Keyword(s):  
Boric Acid ◽  
Acid Concentration ◽  
Reactor Core ◽  
Heat Removal ◽  
Vver Reactor ◽  
General Nature ◽  
Droplet Entrainment ◽  
Positive Effects ◽  
Operation Conditions ◽  
Wide Range

Process of boric acid mass transfer during accidents accompanied with rupture of circulation pipelines in VVER reactors of new generation equipped with passive safety systems are examined. Results of calculation of variation of boric acid concentration in VVER-TOI reactor in case of accident development process are presented. Positive effects of boric acid droplet entrainment on the processes of acid accumulation and crystallization in the reactor core are demonstrated. The obtained results allow formulating the conclusion on the possibility of these processes in the reactor core which may lead to the disruption of heat removal from fuel pins. Review of available published reference data on physical properties of boric acid solutions (density, viscosity, thermal conductivity) is given. It is established that available information is of too general nature and fails to cover the whole range of parameters (acid temperature, pressure and concentration) typical for potential emergency situation on NPP equipped with VVER reactor. Necessity of experimental study of processes of droplet entrainment under parameters typical for VVER emergency operation conditions, as well as investigation of thermal physics properties of boric acid within wide range of acid concentration values is required.

Sign in / Sign up

Export Citation Format

Share Document