nuclear radiation detection summary

7/27/2019 Nuclear Radiation Detection Summary

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3. Nuclear Radiation Detection Rate -

Detector Sensitivity Scales

Scale Rems/Hour Sieverts/Hour Danger Level after 1 Hour

ReportedFukushimaRadiationLevels

1

2

3

4

5

6

78

9

10 Rems

100 Rems

1 mRems

10 mRems

100 mRems

1 Rem

10 Rems100 Rems

500 Rems

0.1 Sv

1 Sv

10 Sv

100 Sv

1 mSv

10 mSv

100 mSv1 Sv

5 Sv

Background radiation

Low level radiation

Daily human limit RATEDo not stay here

Substantial exposure

Strong exposure

Extreme danger50% chance of death

CDV-715 highest scale

10Sv

400Sv

10 mSv

400 mSv

Human Radiation Damage - "Linear No Threshold"For years, we were told that low-level radiation won't hurt us. Exposure Limits

were set at what were believed to be "safe levels", AKA "acceptable levels".

In reality, there are no "safe levels". Most scientists now concede that ANY

amount of radiation CAN be harmful (there is no minimum threshold, above

which damage "occurs").

Ionizing radiation damage is cumulative, and is proportional to exposure.Reduce your total exposure, to protect your health.

A very small exposure is worse than no exposure.

Is it inevitable that these Fukushima radioisotopes will rise into the atmosphere,

and be carried by the jet stream to the west coast of Canada and the United

States? Yes.

Will this radiation result in thousands of new cancers in California? No.

Will the overall cancer rate in California rise slightly due to increased

background radiation? Yes.

Can anyone say by how much? No.

The GE Mark 1 Reactor Design

Who was the person who decided to store the used fuel rods, now containing

plutonium, in a cast cement tank, ON TOP of the reactor?

These rods should have been stored ANYPLACE ELSE.

Who APPROVED this design?

Pure insanity.

INFORMATION FLOW - We Still Don't Know

Things are worse than we are allowed know -

Tokyo Electric Power ---> censored info ---> Japanese Government --->
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more censorship ---> available information to outside world

Wouldn't we do the same thing? Reduce panic. Prolong ignorance.

Sanjay Gupta Is Ill-informedMost people are getting their Japan radiation information from CNN. EVERY

time that Sanjay has opened his mouth since March 11, he has demonstrated hisutter lack of knowledge about radiation. I just wish I had written everything

down. On ONE DAY, in ONE interview, he made FIVE absurd pronouncements.

At one point, he tried to explain the difference between a dosimeter and a Geiger

counter - he failed miserably.

On Tuesday March 22, he said something to the effect - "These short half-life

isotopes will decay quickly, but NOT if they are buried underground, where it

will take decades". WHAT? They will decay underground JUST AS QUICKLY

as above ground. The half-life of an isotope DOES NOT VARY, no matter

where you put it. There are 5th graders who can put this guy down.

Somebody needs to gag this guy, because he is making all his listeners dumber

than dirt. And they wanted to make him Surgeon General? AHH-HA-HA-HA. I

don't think so..

Practicing neurosurgeon? That is just plain scary. I guess he cuts into people's

brains, in between spewing disinformation to the masses.

Sometimes, PHD simply means Piled Higher and Deeper. It doesn't mean he is

smart - it simply means he put up with a ton of academic hoop-jumping.

40 100 100 240-590 100

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4. CPM vs. mR/hr - Probe Sensitivity

Meter

GeigerCounter

Probe Model #

CPMFull

ScalemR/Hour

Full ScaleSensitivity

CPM/mR/hr

12

3

4

5

6

Ludlum 44-2CDV-700 #6b

Bicron 50 EWGM

Bicron 2000Ludlum 44-6, 38

Eberline 120 Pan

200300

600

2,400

2,400

6,000

5 mR0.5 mR

0.5 mR

2 mR

2 mR

5 mR

40600

1,200

1,2001,200

1,200

7

8

9

Ludlum 44-7 End

Ludlum Model 3

Ludlum 44-9 Pan

4,200

5,000

6,600

2 mR

2 mR

2 mR

2,100

2,500

3,300

Meter faces will vary by a factor of 80 to 1, in terms of thecorrespondence between Counts per Minute and
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milliRems/hour. Some example meter readouts are shown

above. Probe sensitivity is the big factor here. A very sensitive

probe will require fewer counts to determine mR/hour rates.

Put another way, at a given mR/hour rate, more counts will be

observed using a very sensitive probe.

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4.5. CPM vs. mR/hr for a given CPM/mR/hr

TruemR/hr

From Least Sensitive -----------> over 5 Times More

Sensitive

(CDV-700)CPM @

mR/hr = 600

(Bicron 50)(Bicron 2000)

CPM @mR/hr = 1,200

(Ludlum)CPM @

mR/hr = 2,500

(Ludlum)CPM @

mR/hr = 3,300

0.01

0.02

0.05

0.1

0.2

0.51

25

10

20

50100

200

500

1 REM

6

12

30

60

120

300600

1,2003,000

6,000

12,000

30,00060,000

120,000

300,000

600.000

12

24

60

120

240

6001,200

2,4006,000

12,000

24,000

60,000120,000

240,000

600,000

1,200,000

25

50

125

250

500

1,250

2,500

5,00012,500

25,000

50,000

125,000250,000

5,000,000

1,250,000

2,500,000

33

66

132

330

660

1,650

3,300

6,60016,500

33,000

66,000

165,000330,000

660,000

1,650,000

3,300,000

Trying to provide a direct "CPM to mR Scale" from the

above chart above this one.

0.01 mR/hr equals background radiation levels.

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5. US Citizen Annual Radiation DOSE

Radiation SourceAverage Annual Whole Body Dose

(millirem/year)

Natural:
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Cosmic

Terrestrial

RadonInternal (K-40, C-14, etc.)

27 mR

28 mR

200 mR40 mR

Sun, quasars

Rocks, water

Most of total -> dirtFood, breathing

- 295 (82%)

Manmade:

Diagnostic x-ray

Nuclear Medicine

Consumer Products

Others (fallout, air travel,

etc.)

39 mR

14 mR

11 mR

2 mR

10 = 390 mR

Barium colon?

Salt, smoke detectors

Occupational

- 66 (18%)

Average annual total360

mRem/year360 (100%)

Source: University of Rochester, annotated

Suggested Annual

Occupational Limit -

Individual

5,000 mRem

(5R)360 above = 7%

Suggested AnnualOccupational Limit -

Pregnant Woman

500 mRem

(0.5R)360 above = 72%

DISCLAIMERI know very little about nuclear radiation.

Although the author has tried to be as accurate as possible, errors arepossible.

I could not find a Radiation Detection summary like the above. So, Imade this ionizing radiation detection summary chart, to help myself

understand the technology. I hope that it helps you.

I am an electronics engineer by trade, who knows little about nuclear

radiation. Please verify all data above. Nuke dudes, please correct me -

I'm trainable! This stuff has always intrigued me.

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Vaughn's Summaries2006, 2011 Vaughn Aubuchon ... All Rights Reserved

www.vaughns-1-pagers.com

This Vaughns Nuclear Radiation Detection Information summary web page was updated on 2011-03-2
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