> -----Original Message----- > From: Bill Anderson [mailto:[EMAIL PROTECTED] > Sent: Thursday, July 31, 2003 10:56 AM > To: [EMAIL PROTECTED] > Subject: [OT] Re: About your .sig
> External radiation exposures may occur when personnel are close to DU > due to its beta and gamma radiation. Studies of external radiation > measurements inside tanks show that the tank commander, gunner, and > loader receive a radiation dose rate of 0.00001-0.00002 rem/hour, an > amount which is somewhat less than the average natural background rate > of about 0.00003 rem/hour. The tank driver may receive slightly higher > dose rates of 0.00003 (gun pointed forward) to 0.00013 > rem/hour (bustle fully loaded with DU ammunition pointed forward), when the driver’s > hatch is open. This means the driver inside a fully loaded > "heavy armor" tank (a model using DU armor panels) continuously, 24 hours a day, 365 > days a year, would still receive a dose of less than 25% of > the current, annual occupational limit of 5 rems. Studies have also shown that the > maximum dose rate outside the tank approaches 0.0003 rem/hr > at the front of a HA turret or over a fully loaded bustle. Continuous exposure at > that level would produce an annual dose of about 2.6 rems or slightly > more than one-half the occupational limit. Fortunately, these exposure > scenarios represent very unlikely situations. Actual > exposures based on realistic times spent in the tanks are likely to be less than > 0.1 rem in a year.""" --Bernard Rostker I find THIS interesting; as someone who worked in military nuclear reactors for over 5 years (and I mean worked IN the Reactors, not just "I was on a ship"; I was a civilian Radiological Control Officer for the Navy) these numbers seem a bit high for the total dosage. On our most sensitive Gamma instruments, the granite quarry stone in the drydocks showed up as 0.04 to 0.92 MR/Hour (in this case for easy of conversion, just suffice that there's pretty much a direct equivalent between the units; however, we measured dosages in millirems instead of hole rems; of course the units are Roentgens, but then REM is "Roentgen Equivalent Man", the dosage of a human to one Roentgen, so it's fair to be a little lazy with R, REM, MR, and MREM, although your units are R, not REM, since you're talking about a radiation reading, and REMs are DOSAGES). <humor>Of course, that means that we need to outlaw that dangerous Granite block! And hey, where do you find lots of Granite slabs? In a cemetery! Coincidence? I think not! </humor> We won't even get started on how radioactive the mantles for Propane Gas camp lanterns are; they would set off our Friskers from 10 feet away. In truth, you get ~100mrem every time you take a flight across the continent. Every time you have an X-Ray, you get 50mrem or more. If you live in the Rocky Mountains in the US, congratulations, you're getting an extra 500mrem a year just sitting at home. Reading this message on a CRT? Good, if you spend 8 hours a day, for a year, in front of a CRT at 2 feet, you'll get something like an additional 40mrem. Got a microwave oven? OH, YEAH..... if it's got leaky seals, you might get 10 mrem or more every time you pop popcorn; even if the seals are good, you'll get about 15 over the course of a year if you pop just one bag a day. So, you say that sitting on a BUNCH of DU shells would give 0.3 MR/Hour (and you definitely mean MR, not MREM, though like I said it doesn't really matter if you get lazy on units, it still works ok because of the way the units are measured)? That isn't radioactive, Magee</ancient radio voice>. Not in comparison to MANY other things. We're talking about a total (unrealistically) of ~250 mrem per year for the tank crew, under bad conditions. More realistically, we're talking less than 100 mrem per year. That's just under the area where you need to monitor the crew. Of course, OSHA allows 5000 mrem/year; the military allows 500 mrem/year without a waiver (from the Radiological Health Monitoring folks) for exposure. The military, as a matter of practice, don't allow more than 2000 mrem/year, except in an emergency. In an emergency dosage, you wouldn't see any significant health effects until you get to ~100000 mrem (100 REM), although some very sensitive blood tests show anomalies over about 40 REM (single dosage events, BTW) No health effects have ever been seen other than a VERY slight increase in cancer over long time, very low dosage. The cancer rates are just at the noise level, however, but to be conservative, the military accounts for it. This includes folks who (from past exposures) are well over the thresholds; the military doesn't allow them exposure NOW, but the guidelines weren't quite as stringent in the 50s and early 60s, and the experience of the Soviets is also germane (they routinely run at dosages far beyond acceptable to the US, GB, and France, even as much as 30 to 50 times higher than permissible limits here). > Basically, you get far more uranium exposure sitting right > where you are > than you do form being in an area a DU shell or two, or three > is. Heck, > walk over and sit next to your smoke detector and you get *more* > radiation than a DU round has. > > Further, Tungsten displays no sharpening capabilities on > impact, making > it *less* effective, not 'just as". In fact, Tungsten has > more insoluble > compounds when inhaled than does uranium. Which is why we don't use Tungsten anymore; it's not as massive, it blunts on impact and shatters instead of sharpening and penetrating, and Tungsten requires a larger volume requiring larger stabilization surfaces for the penetrator. > Thank you for playing "Name that FUD". I'm all for people > having causes, just be smart about them. Now, we've about exhausted a TOTALLY OT subject on a normally on topic list. Can we go back to Linux? Bill Ward -- redhat-list mailing list unsubscribe mailto:[EMAIL PROTECTED] https://www.redhat.com/mailman/listinfo/redhat-list
