Radiation dose sub vs. carrier

[Bradbbr96]

Hi I'm new to the forum. My brother has been working as a civilian marine machinery mechanic specializing in valve repair on nuc ships for several years and I'm waiting for clearance to begin Radiation Control Tech training.

My question is mostly out of curiosity: Is there a significant difference between subs & carriers when it comes to the radiation exposure for workers such as nuc mechanics & rad con techs?

I realize cumulative exposure is low compared to commercial systems (I believe Navy limit is 500millirem/yr) and would be variable depending on exactly what nuclear component is being repaired where on the ship, but I'm thinking in terms of a general/overall comparison. I assume the nuclear system is smaller on a sub because the vessel itself is so much smaller than a carrier and thus should require less energy to be produced for propulsion. But the RC and associated pipes, valves, etc. that require regular maintenance would also be in a tighter space with possibly less allowance for shielding and a higher density of radioactive material running around personnel in a given area?

I searched for info relevant to my query first, but couldn't find anything specific enough, apologies if it's been covered before. I also apologize for any butchering of terminology or concepts. I'm new to this field, but enthusiastic to learn.

[Mounder]

Just based on the shear size of carrier versus the confined nature of sub, the person-REM must be higher in a sub.

[Marlin]

Just based on the shear size of carrier versus the confined nature of sub, the person-REM must be higher in a sub.

   Exposure during patrol would be lower on a sub. Most sailors on the boat minus the duty ELT are in a lower than inport background. Much lower terrestrial and cosmic background radiation, you can see the drop on a frisker background after a dive. In reverse any backgrounds done submerged may cause false positives on scalers. Maintenance is another story most sub sailors I know got more accumulative exposure. Smaller crew? Cramped working conditions? I had 3.5 R after 8 years about half my time was in the yards. I was on an older boat a 637 the 688s had much more room in the engineering spaces. Strangely enough we had more berthing than the 688s.

[thenukeman]

The current Federal annual occupational radiation exposure limit of 5 rem was established in 1994, which is 27 years after the Naval Nuclear Propulsion Program's annual exposure limit of 5 rem per year was adopted in 1967.  (Until 1994, the Federal radiation exposure lifetime limit allowed an accumulation of exposure of 5 rem for each year of age beyond 18).  From 1968 to 1994, no civilian or military personnel in the Program exceeded its self-imposed 5 rem annual limit, and no one has exceeded that Federal limit since then.  In fact, no Program personnel have exceeded 40 percent of the Program's annual limit from 1980 to 2012 (i.e., no personnel have exceeded 2 rem in any year in the last 33 years).  And no civilian or military Program personnel have ever, in almost 60 years of operation, exceeded the Federal lifetime limit.

Found  this  will  look  more.

[OldHP]

The current Federal annual occupational radiation exposure limit of 5 rem was established in 1994, which is 27 years after the Naval Nuclear Propulsion Program’s annual exposure limit of 5 rem per year was adopted in 1967.  (Until 1994, the Federal radiation exposure lifetime limit allowed an accumulation of exposure of 5 rem for each year of age beyond 18).  From 1968 to 1994, no civilian or military personnel in the Program exceeded its self-imposed 5 rem annual limit, and no one has exceeded that Federal limit since then.  In fact, no Program personnel have exceeded 40 percent of the Program’s annual limit from 1980 to 2012 (i.e., no personnel have exceeded 2 rem in any year in the last 33 years).  And no civilian or military Program personnel have ever, in almost 60 years of operation, exceeded the Federal lifetime limit.

Actually, the limit was 5N-18, (accepted as 1.25 Rem/quarter) not to exceed 3 Rem/quarter, except in emergency situations!  In the 60's,70's, and 80's few folks, other than in accident situations, exceeded the 5 Rem.  In fact in the late 60's and early 70's 7.5 Rem/year was the accepted max in both the NNPP and commercial world, as long as you maintained an average of much lower than 5 Rem (the average was what was looked at, not the max)!

[Gamecock]

And no civilian or military Program personnel have ever, in almost 60 years of operation, exceeded the Federal lifetime limit.

What about the folks from SL1?

Cheers,

GC

[GLW]

And no civilian or military Program personnel have ever, in almost 60 years of operation, exceeded the Federal lifetime limit.

What about the folks from SL1?

Cheers,

GC

2015 - 1962 = 53

53 = almost 60 years,...

2015 - 1961 = 54

54 =  
               

[GLW]

Just based on the shear size of carrier versus the confined nature of sub, the person-REM must be higher in a sub.

exactly what is the shear size of a carrier?!?!?

[surf50]

In the 60's,70's, and 80's few folks, other than in accident situations, exceeded the 5 Rem.  

In the commercial world it was fairly common for S/G jumpers to exceed 5 Rem.
I'm sitting here looking at my 1981 daily Dept. exposure printout (on thermal paper, no less!) that has me at 6820 for the year.

I was somewhat naive at the time.