Radioisotope Thermal Generator

[Brian]

Let it be known that I am just a second year engineering student.

However, I am still looking into the range of the Nuclear Engineering field and was wondering about the radioisotope thermal generators.  From what I have found out so far, they are used in remote sites where solar or petroleum just wont work for power supplies.  But just like anything, I would have to assume that they would need some kind of periodic maintenance, along with the current development of newer models.  So to anyone's knowledge, is there much of a field working and or designing these things?

The main reason for asking such a question is that for a while after school, I wouldn't mind traveling and working outside.

If anyone has other ideas on work that can fit in those categories, please let me know.

Brian

[HydroDave63]

I wouldn't mind traveling and working outside.

Did they leave the RTG out in the rain???

[RAD-GHOST]

RTG's are definitely a unique field and are usually designed for a very specific purpose.  As far a servicability, there isn't much!  Usually the only servicing performed on a RTG is the disassemby of the unit for recovery of the radioactive material, prior to final disposal.  The primary isotopes used in RTG's are Sr/Y-90 and Pu-238.  Both pack quite a punch due to their specific activities and ability to be shielded due to their mode of decay.  Both produce a large amount of heat during their decay.  The heat is converted to electric current via, (HOPE I SPELLED THIS RIGHT), Thersistors.  The exchange is pretty inefficient so most RTG's are designed for low voltage operations, but for long time operations, some as long as 50+ years!  Sr/Y-90 RTG's range in size from about 60,000 to 180,000+ curies and are capable of generating temperatures as high as 900 degrees  "C".....SMOKING!  RTG's are usually stationed in VERY remote locations and you probably wont find any within driving distance of your house, unless you happen live in an area where you could die in second due to environemental factors, (Space, middle of the ocean, north pole, ect..)  There are several published incidents where individuals have found these devices and decided that their protective shields are hiding untold treasures!  After busting the puppy to pieces, most never get a chance to tell their story!

RG!












 

[Gamecock]

You didn't spell it right....it is thyristor....but otherwise a very good description.

Cheers,
GC

[RadEngineer]

RTG's are usually stationed in VERY remote locations and you probably wont find any within driving distance of your house, unless you happen live in an area where you could die in second due to environemental factors, (Space, middle of the ocean, north pole, ect..)

The first application of RTGs that ever came to my attention was, in fact, for the space program....to power the equipment aboard interplanetary probes.
So Brian, NASA and its subcontractors may be an area of employment that you'd want to explore.
While working at the decommissioning of the Mound site (DOE/DOD Ohio) I learned that the site had supplied the radioisotopes used in some NASA RTGs...I believe, though, that they were only a supplier and were not involved with fabrication of the final assemblies. Still, another place to inquire.

[X-Nuke]

I think most of the research in this area is still around deep space power generators.  Check for a project with Boeing Rocketdyne and DOE for the MMRTG project.  You might be able to work this into a co-op opportunity as part of your engineering program.

Bill

[matthew.b]

You didn't spell it right....it is thyristor....but otherwise a very good description.

Cheers,
GC

Aye, but a thyristor is a type of semiconductor switch.  You're looking for thermocouple.

Yep, the very same device that makes electricity to keep gas valves open using the pilot heat (and conversely, turn off the gas if the pilot goes out).

[RAD-GHOST]

Aye, but a thyristor is a type of semiconductor switch.  You're looking for thermocouple.

Correct-A-Mundo!

RG!

[RDTroja]

Way back when, there was a company called Hittman Nuclear Battery Corporation, a subsidiary of Hittman Associates (the same company that started Hittman Nuclear and Development Corporation which has been since bought and sold by Westinghouse and Duratek.)

Hittman Nuclear Battery Corp. made batteries for space probes and, believe it or not, heart pacemakers. They used mostly Pu238, but experimented with other isotopes including Am241 (very bad memories about a liquid Americium source.) The space probe information was mostly classified (they were made for various relatives of Uncle Sam), but the general 'shop talk' was that the batteries would outlast the probes by hundreds of thousands (or millions) of years. The development of the lithium-ion battery put an end to the batteries usefulness for pacemakers. The basic design was the same then as now -- decay heat converted to electricity by thermocouples. Simple, elegant and no moving parts or maintenance.

Unfortunately I can't find any evidence of Hittman Nuclear Battery being anything more than a memory. Shortly after I left there in 1975, Fred Hittman died and the only real money maker was HNDC, which transported radwaste and performed decon/waste solidification services. They were sold to Westinghouse and, I think, then to Duratek. I still occasionally see Hittman Transport Services trucks around. Haven't seen any Hittman batteries, though.