Jill Belcot Radiation Science and Health PhysicsJarrett Johns Nuclear Engineering

Ethan Werger Nuclear Engineering

Thesis Advisor Dr. Anthony Waker

Construction of a Whole

Body Counter for Non-

Human Biota

Introduction The construction of a whole body counter

to measure radioactivity in non-human biota

Two units built for the examination of beta radiation and gamma radiation

Aluminum and lead used for shielding of the unit

Internal and external dose rates were calculated

Objective

Build two units to detect gamma radiation and beta radiation

Determine appropriate shielding configurations

Calculate internal and external gamma and beta dose rates to the frog from Cs-137

Evolution of Testing Equipment

Gen 1 Gen 2

Evolution of Testing Equipment

Gen 4 Gen 4

Evolution of Testing Equipment

Gen 5

Evolution of Testing Equipment

Evolution of Testing Equipment

Evolution of Testing Equipment

Evolution of Testing Equipment

Equipment Creation Issues Securing over 400 lbs. of pre WW2

fallout lead Creation of mold Welding lead casting mold Heating mold up to 328°C Staying on track for both the schedule

and budget

Results

Gamma Interactions

0 100 200 300 400 500 600 700 800 900 10001

10

100

1000

10000 Background With Sheilding

Series1

Channel Number

Coun

ts

𝐵𝑎𝑐𝑘𝑔𝑟𝑜𝑢𝑛𝑑=𝑇𝑜𝑡𝑎𝑙𝑐𝑜𝑢𝑛𝑡𝑠𝑇𝑜𝑡𝑎𝑙𝑡𝑖𝑚𝑒 =

285647174345=1.628(𝑐𝑜𝑢𝑛𝑡𝑠Sec )

Gamma Interactions

0 100 200 300 400 500 600 700 800 900 10001

10

100

1000

10000

100000

Cs Source With Sheilding

Series1

Channel Number

Coun

ts

𝐶𝑜𝑢𝑛𝑡 𝑅𝑎𝑡𝑒=𝑇𝑜𝑡𝑎𝑙𝑐𝑜𝑢𝑛𝑡𝑠𝑇𝑜𝑡𝑎𝑙𝑡𝑖𝑚𝑒 =

1756554300 =5855.18(𝑐𝑜𝑢𝑛𝑡𝑠Sec )

NaI Detector

𝑒𝑓𝑓𝑖𝑐𝑒𝑛𝑐𝑦=(5855.18( 𝑐𝑜𝑢𝑛𝑡𝑠sec )−1.628(𝑐𝑜𝑢𝑛𝑡𝑠sec ))

30 461(𝑑𝑖𝑠𝑖𝑛𝑡𝑒𝑔𝑟𝑎𝑡𝑖𝑜𝑛𝑠𝑒𝑐 )=19.21%

Gamma – No Shield

0 100 200 300 400 500 600 700 800 900 10001

10

100

1000

10000

100000

1000000Background Without Sheilding

Series1

Channel Number

Coun

ts

Gamma With Lead Shield

0 100 200 300 400 500 600 700 800 900 10001

10

100

1000

10000Background With Sheilding

Series1

Channel Number

Coun

ts

Gamma

0 100 200 300 400 500 600 700 800 900 10001

10

100

1000

10000

100000

1000000 Comparison of Shielding

No shield-ing

Shielded

Channel Number

Coun

ts

Beta Interactions

0 100 200 300 400 500 600 700 800 900 10001

10

100

1000 Background Without Sheilding

No shield-ing

Shielding

Channel Number

Coun

ts

Beta- Cap Efficiency

0 100 200 300 400 500 600 700 800 900 10001

10

100

1000

10000 Cs 137 With and Without Cap

With capWithout Cap

Channel Number

Coun

ts

Beta- Cap Efficiency

Effects of Radiation Assume the frog absorbs Cesium like a

human, cesium is distributed everywhere in the body

Effects of Radiation – Internal

Effects of β Radiation - Internal Intake of Beta in the frog is equal to one

The frog will absorb all of the Betas

For Cesium-137:

= 0.18669 MeV

Effects of Radiation - Internal 93% probability that gamma energy will be emitted

for Cs-137

Mean energy per emission is 0.662 MeV

7% of the energy emitted from the gamma particle will stay in the frog.

Effects of Total Internal Radiation – β and

The committed absorbed dose can then be calculated:

External Beta Skin Dose VARSKIN is a computer code for skin

contamination dosimetry

Layers of the Skin

Thickness (µm)

Mucus 75Epidermis 110

Dermis 300

External Beta Skin Dose – VARSKIN

External Beta Skin Dose Hand Calculation

𝐸𝑎𝑏𝑠𝑟𝑜𝑏𝑒𝑑=( 𝑡𝑜𝑡𝑎𝑙 h𝑡 𝑖𝑐𝑘𝑛𝑒𝑠𝑠𝑅𝛽

𝑥 𝐸𝛽)=0.599𝑀𝑒𝑉

𝐷=𝐴𝑥1.846 𝑥10−13𝐺𝑦=2.458𝑥 10−13 𝐺𝑦h𝑟

Conclusion on Dose Rates The frog accumulates the Cesium 137, the frog

receives a higher internal dose than external dose

There is a lack of data on effects of radiation on many organisms, including amphibians.

Many factors affect the amount of radiation that a frog can be exposed to

Conclusion Testing apparatus met our design

requirements and provided accurate results

Based on our detector response, it was determined we can detect a wide range of radiation from background to lethal

Dose calculations proved the frog will be receiving both an internal and external dose from the 1µCi source.

Special Thanks Thesis Adviser: Dr. Waker Construction of apparatus:

-Tuthill Metal Works-Shurer Custom Machining-Vic Powell Welding & Crane-Bill Battle-Bill Moyer-Rick Werger-Brent Thornhill-John Hart Sr. -Dave Green