SENSORS FOR INTRA-REACTOR CONTROL OF HYDROGEN AND OXIGEN IN LIQUID SODIUM

Authors & Affiliations

Blokhin V.A., Borisov V.V., Kamayev A.A., Kukharchuk O.F., Meshakin V.I., Pakhomov I.A., Poplavsky V.M., Suvorov A.A., Trufanov A.A.
A.I. Leypunsky Institute for Physics and Power Engineering, Obninsk, Russia

Blokhin V.A. – Leading Researcher, Cand. Sci. (Tech.), A.I. Leypunsky Institute for Physics and Power Engineering. Contacts: 1, pl. Bondarenko, Obninsk, Kaluga region, Russia, 249033. Tel.: +7(910) 524-97-14; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..
Borisov V.V. – Deputy Head of Laboratory, A.I. Leypunsky Institute for Physics and Power Engineering.
Kamayev A.A. – Deputy Director of Department, Cand. Sci. (Tech.), A.I. Leypunsky Institute for Physics and Power Engineering.
Kukharchuk O.F. – Deputy General Director, Director of Department, Dr. Sci. (Phys. Math.), A.I. Leypunsky Institute for Physics and Power Engineering.
Meshakin V.I. – Deputy Head of Department, Cand. Sci. (Tech.), A.I. Leypunsky Institute for Physics and Power Engineering.
Pakhomov I.A. – Head of Laboratory, A.I. Leypunsky Institute for Physics and Power Engineering.
Poplavsky V.M. – Deputy General Director for Fast Reactors, Dr. Sci. (Tech.), Professor, A.I. Leypunsky Institute for Physics and Power Engineering.
Suvorov A.A. – Head of Department, Dr. Sci. (Phys. Math.), A.I. Leypunsky Institute for Physics and Power Engineering.
Trufanov A.A. – Deputy General Director, Director of Safety Department of NPP, A.I. Leypunsky Institute for Physics and Power Engineering.

Abstract

We report on development of electrochemical type sensors for liquid sodium purity control used as coolant in fast reactors and power plants. Oxygen sensor contain gadolinium-doped hafnium oxide, hydrogen sensor contain yttrium-stabilized zirconium oxide as solid electrolyte.
The time-resource experiments were carried out at the isothermal liquid sodium circulating stand within the temperature range of 300-500°C. The dissolved oxygen concentration varied from 0,1 to 14 ppm. The hydrogen concentration covers the range from 0.04 to 3,8 ppm. The experiments showed the stability of sensors characteristics up to 10⁴ hours.
The effect of ionizing dose rate of in-reactor irradiation on the performance of sensors was studied with the use of reactor Bars-6. Sensors were installed on the hot side of specially constructed thermal convection loop. It is shown that:
- the sensor of oxygen properly controls the change of oxygen dissolved in liquid sodium;
- the sensor of hydrogen properly controls the change of hydrogen dissolved in liquid sodium;
- all sensors are characterized by high stability of indications;
- in-reactor gamma irradiation with dose rate in the range 2-200 mGy/s demonstrated small reduction of output voltage of sensors without substantial harmful effect on the sensors performance;
- with the growth of temperature of liquid sodium, the effect of dose rate decreases;
- after removal of irradiation the output voltage of sensors restores to their initial values without any degradation in performance.

Keywords
sodium, control, oxygen, hydrogen, sensor, solid oxide electrolyte, gamma irradiation, thermal convection loop

Article Text (PDF, in Russian)

References

UDC 621.039.51.17

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2017, issue 4, 4:1