The 6th International Symposium on Material Test Reactors (ISMTR-7) 20-23 Oct. 2014, Otwock-Swierk, Poland
Development of Radiation Resistant Development of Radiation Resistant
In-water Transmission System
, H. Shibata1
, S. Ueno1
, T. Shibagaki2
, H Komanome2
and K Tsuchiya1
and K. Tsuchiya1
1: Japan Atomic Energy Agency, 4002 Narita, Oarai, Higashiibaraki, Ibaraki 311-1393, Japan 2: Ikegami Tsushinki Co., Ltd, 3-6-16 Ikegami, Ohta-ku, Tokyo, 146-8567, Japan
○ Selection of important information about the nuclear facility.
○ Development of transmission system which available under severe accident.
○ Selection of important elements for observation system in the nuclear facility and
○ Selection of important elements for observation system in the nuclear facility, and demonstration of it.
Spent fuel storage pool
Measuring instrument Receiver
Wireless transmission technology (underwater)
Development of transmission system which available with small electrical voltage in severe condition.
We started from 2012 a research and development so as We started from 2012 a research and development so as to monitor the NPPs situations during severe accidents.
Considering that reactor buildings could be filled with water Considering that reactor buildings could be filled with water under the severe accidents, a development of an in-water wireless transmission system was started. y
Our group completed the basic design of the system and the radiation-resistant tests of the candidate transmittingg and receiving devices by the end of FY2013. In this presentation, the results of the gamma irradiation tests of the devices, and preliminary of a developed transmission test system will be reported.
Comparison of Transmitting Method under Water
Radio wave Visible light Sonic wave
△ ○ ○
Status g △ ○ ○
Range Several meters Unknown Several hundred
・Existence of many general purpose components
F t T i i
・Resistant to EM- noise
・Small Attenuation in
・Fast Transmission the water
・Large electricity consumption
・Influence of the other light noise
・Slow transmission Large transmitter Disadvantages consumption
・Available only low frequency
other light noise
・Large scattering ・Large transmitter
E l f U d t U d t
Examples of use
In water Underwater
Transceivers Communication device Underwater Transceivers
Visible light has low attenuation coefficient in water and enough transmission rate.
Thus, we use visible light against underwater wireless transmitting system. 3
Considering Suitable Light Wavelength
Influence of Cherenkov light Optical absorption coefficient of distilled water
of distilled water
Thermal output of KUR : 1MW Depth of water : 6m
Rapid increase slightly more than 600nm
n coefficie -3 cm-1 )
nW/cm2 / Rapid decrease slightly
less than 600nm
diance (n 0 20.2 Ab
Th lt t th t it bl li ht l th i b t f 550 650
Wave length (nm) Wave length (nm)
The results suggest that suitable light wavelength is about from 550-650 nm.
Samples of LED and PD
Item LED-A LED-B LED-C
【 Light Emitting Diode (LED)】
S face of eflection
Material Epoxy resin
Surface of reflection
Cathode Leadframe Anode
Leadframe Material Epoxy resin
Wave length 575nm 609nm 635nm
P 0.31mW 2.48mW 4.64mW
Item PD-A PD-C
【 Photo Diode (PD)】
Short wave Long
glass Borosilicate glass Silicone resin
P layer N layer
Insulator film Depletion wave
area 33mm2 7.26mm2
Outline of Gamma-rays Irradiation Tests
Characteristic tests of
i di d l
Spectro-scope Adjustable light
G i di ti
beam generator LED
・Total luminous flux
Gamma-rays irradiation (1)
Gamma Irradiation Field
Characteristic test of irradiated samples
60Co Total dose
(kGy) 10,20,50, 100,1000
(2) source (kGy) 100,1000
Characteristic tests of irradiated samples
Irradiation Effect on LEDs (1/2)
Current-voltage curves of LEDs
100 LED A（ l th 575 ） LED C（ l th 635 ）
LED-A（wave length：575nm） LED-C（wave length：635nm）
ent （m A
1.4 1.6 1.8 2.0 1.4 1.6 1.8 2.0
Voltage （V） Voltage （V）
Properties between current and voltage are almost stable up to 1000kGy.
Voltage （V） Voltage （V）
No significant difference about electrical properties for total dose
Irradiation Effect on LEDs (2/2)
Dose 0kGy 50kGy 1000kGy
Degradation of total
luminous flux with total dose
Sample 0kGy 50kGy 1000kGy
ux[lm] at 0 kGy) (575nm)
umiousflu ized to 1 a
(635nm) Total lu (normali 0.2
10 100 1000
Epoxy resin of LED changed brown.
The total luminous flux reduced with increasing of dose.
Colored epoxy resin of LED lenses absorb light.
⇒ Total luminous fluxes decrease.
Irradiation Effect on PDs (1/2)
Appearance of PDs after 1000kGy irradiation
Window material Quartz glass Borosilicate glass Silicone resin
Cross section inspection
Silicone resin (brown) Case
ResultQuartz glass did not
change even at 1000kGy. Silicone resin was colored to brown.
change even at 1000kGy. to brown.
Irradiation Effect on PDs (2/2)
Degradation of light sensitivity with total dose
[A/W] at 0 kGy)
0 4 0.6
to 1 a
Light se normali
z Silicone & Borosilicate glass
10 100 1000
Browning of the silicone resin makes the light sensitivity decrease.
Quartz glass is desirable for window material of PD.
Underwater Transmitting Testing System
Testing System Waveform of Transmit and Receive
1m Remove reflected
at inner surface Sending signal
Connectable 6 units (max 6m)
PD output signal
LED sender circuit PD receiver circuit
Digital output signal