Radionuclide thermoelectric generator RTG

Application, structure and characteristics of radionuclide thermoelectric generators – RTGs

Radionuclide thermoelectric generator – RTG is based on the conversion of heat released during radioactive decay of the radionuclide, into electrical energy direct current through the semiconductor thermoelectric battery (hereinafter PTAB).

The main areas of current and future applications of RTGs are:
1.Using them as power sources for navigation objects (light-beacons, beacons, beacons-defendants, navigation and marker posts), located in remote and inaccessible parts of the coast and Islands of the seas washing territory of Russia, including along the Northern sea route.
2.Use them to power the seismic equipment for the continuous monitoring of seismic activity in order to detect nuclear tests.
3.Use them to power Autonomous items of radio relay communication lines and stand-alone weather observation points..
4.Use them as power sources for scientific equipment space and subsea applications, hardware alarm critical facilities.

Radionuclide thermoelectric generators, their principle actions are the most reliable self-contained sources of electrical energy DC. They work at negative and high positive temperatures of the environment, in space, on earth, under earth and under water. Radionuclide thermoelectric generators are characterized by the output electric power from fractions of Watts to tens of Watts and the output electric voltage from a few volts to tens of volts, maintenance-free service life more than ten years.

Found the widest application in the national economy RITEG, type Beta-M shown in Fig. 1. There were manufactured and operated more than 800 pieces.

RTGs is characterized by the following parameters:

— maintenance-free lifetime at actual operating results to 20 years;

— output electric power at the beginning of the service life – not less than 9,0 W;

— work output electric voltage of -14 V;

weight – 550 kg;

-operating temperature range – from -60 to + 50 ºC.

In the RTGs as a heat source used radionuclide heat source RIT-90-230, on the basis of the radionuclide strontium-90, the thermal power of 230 watts.

Structural diagram of the RITEG, type Beta-M, which is typical for RTGs other types.

The main elements of the RTGs are as follows:

— radionuclide heat source RIT-90;

— semiconductor thermoelectric battery PTAB;

radiation (biological) protection;

— radiator for heat.

The main characteristics of the developed RTGs watt range of electric power with the use of radionuclide heat sources based on Strontium-90 are shown in tables 1 and 2, and pictures of some of them in figures 1 and 2.

РИТЭГ

RTG «Beta-M»

Picture 1.

 

The main characteristics of low temperature RTGs on stroncii-90:

Table 1

Parameters RTG model
Beta-M Efir IEU-1 IEU-2 IEU-2M Penguin 57 IK
1 Electrical power, W  

9,0

 

30

 

80*

 

14*

 

20*

 

2,0

 

0,5

2 Voltage, V 6 or 14   35     24     6     14      3,0   1,3
3 Heat power, W    230  680   2130   580   650     60   29
4 Dimensions, mm

— diameter (length)

— height

— width

 

600

655

 

805

1275

 

(1510)

1350

760

 

900

720

 

(900)

870

750

 

400

300

 

400

360

5 Weight, kg    565 1200 2300   746   600     300    80
6 Life, years    20   20   20   20    20      20  20
7 Eff, %    3,9   4,4   3,7    2,4    3,1    3,35    1,7

* — all life

The main characteristics of the middle temperature RTGs on stroncii -90

Table 2

Parameters RTG model
Grab Gong Gorn Senostav
1 Electrical power, W  

120

 

18

 

60

 

80*

2 Voltage, V 28 или 14

или 7

  14 28 или 14

или 7

    28
3 Heat power, W   1698  300   1091   1794
4 Dimensions, mm

— diameter (length)

— height

— width

 

850

990

 

680

945

 

850

1230

 

(920)

1450

760

5 Weight, kg    850   600 1050   1250
6 Life, years   20   20   20  20
7 Eff, %     7,0    6,0    5,5    4.5
РИТЭГ

RTG Senostav

Picture 2.

Used radionuclides

Strontium-90

A product of nuclear reactors, refers to radioactive waste.

The half-life of 28 years.

Requires massive radiation shielding

(specific El. the generator power of 0.06 W/kg).

The mass of RTGs on Stroncii-90- 500 -2000 kg.

Used only in stationary devices.

The manufacturing cost is low.

 

Another class of RTG is the watt power generators with the use of radionuclide heat sources based on plutonium-238 for specific purposes or made to special order.

Main technical specifications of RTG in this class are given in table. 3.

Table 3

Parameters Model RTG
      1         2        3     4
1 Electrical power, W    0,02     2,9       12,0      9,0
2 Voltage, V     3,0      3,5       3,5       3,5
3 Heat power, W     1,5      85       200      170
4 Dimensions, mm

— diameter (length)

— height

 

 

60

70

 

200

234

 

300

300

 

250

255

5 Weight, kg     0,2       9         22       15
6 Life, years     50      20         20       20
7 Eff, %     1,3      3,4         5,9       5,1

 

RTGs electric power of 12 W is shown in Figure 3

РИТЭГ 2

Figure 3

Used radionuclides

Plutonium – 238

The half-life of 87 years.

The specific heat of 0.49 W/g (oxide PuO2)

Radiation protection is not required

The isotope is produced purposefully. Production is halted. Stocks are extremely limited. Manufactured products in single units of space and special applications.

Time stopped under international agreements.

If necessary, the operating time can be renewed up to 5000 Watts of heat per year.

The cost of production is high.