Some Useful Information Concerning the results:

The Conversion factors for the primordial nuclides are given by:

1 Bq 238U/kg = 81 ppb U (81 x 10-9 gU/g)

The 238U decay chain gammas used are:

226Ra: 186.1 keV

214Pb: 295.21 and 351.92 keV

214Bi: 609.31, 1120.29, 1764.49 and 2204.21 keV

The relationships are valid for any daughters in the 238U, 235U or 232Th chain only if the chain is in equilibrium.

1 Bq 232Th/kg = 246 ppb Th (246 x 10-9 gTh/g)

The 232Th decay chain gammas used are:

212Pb: 238.63 and 300.09 keV

208Tl: 583.19 and 2614.53 keV,

228Ac: 911.21 keV

1 Bq 40K/kg = 32300 ppb K (32300 x 10-6 gK/g)

The 40K decay chain gamma used is:

40K: 1460.83 keV

1 Bq 235U/kg = 1.76 ppm U (1.76 x 10-6 gU/g)

The 235U decay chain gammas used are:

235U: 143.76, 163.33 and 205.31 keV

The measurements of the samples below take into account the background measurements. If a measurement is below the background then the upper bound shown is the 90% confidence limit.

REPAIR Measurements:

Sample Description

Manufacturer

Mass (g)

Live Time (days)

Counting Dates
(if applicable)

238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co

Comments

REPAIR 01

Two flasks, one from Corning and one from Falcon

84.2 g

9.261

Jul 19, 2017

(mBq/kg)

<4.63

105.99

139.04

4.97

7.31

3.33

6.04

<37.74

<7.76

<1.57

Polystyrene Culture Flasks

July 28, 2017

(ppb or ppm)

<0.38 ppb

8.59 ppb

11.26 ppb

8.75 ppb

12.86 ppb

0.82 ppb

1.48 ppb

<1.22 ppm

REPAIR 02

23.4 g

10.575

Jan 4, 2018

(mBq/kg)

<14.70

639.90

477.78

<85.13

<4.18

<71.75

<2.05

<7.61

Thermocouple Wire

Jan 15, 2018

(ppb or ppm)

<1.19 ppb

51.83 ppb

38.70 ppb

<149.83 ppb

<1.03 ppb

<2.32 ppm

REPAIR 03

294.0 g

6.169

Nov 17, 2017

(mBq/kg)

<2.56

<46.22

<7.47

<1.91

<16.99

<0.56

<0.59

Timken Bearings

The Timken Company

Nov 24, 2017

(ppb or ppm)

<0.21 ppb

<3.74 ppb

<13.15 ppb

<0.47 ppb

<548.88 ppb

REPAIR 04

CGL1 Complete Media
Prepared on June 17, 2019

48.8 g

6.819

Jan 15, 2020

(mBq/kg)

17.80

13.44

211.40

292.00

<8.48

<17.57

8005.10

628.90

<11.41

<7.52

MEM, 1X
Minimum Essential Medium Eagle with Earl’s Salts and L-Glutamine

Corning Cellgro
Lot No. 02819001
– Mixed with N-strep penicillin

Sample Collected by Taylor on Dec 13, 2019

Jan 22, 2020

(ppb or ppm)

1.44 ppb

1.09 ppb

17.12 ppb

23.65 ppb

<14.92 ppb

<4.32 ppb

258.56 ppm

20.31 ppm

REPAIR 05

SC-N
Natural K

45.3 g

9.854

Oct 21, 2022

Results:

238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co

Comments

Yeast Media

Run: 221021
221024
221025
22102701

Oct 31, 2022

(mBq/kg)

12.86

6.67

<520.70

<5.34

<8.31

638.19

118.50

12.48

7.06

31.53

5.72

(ppm / ppb / ppt)

1.04 ppb

0.54 ppb

<42.18 ppb

<9.4 ppb

<2.04 ppb

20.61 ppm

3.83 ppm

Results:

7Be:

54Mn

228Ac:

(mBq/kg)

<50.11

<5.85

<15.69

(ppm / ppb / ppt)

<3.86 ppb

REPAIR 06

SC-39
Refined K-39

45.9 g

8.958

Oct 31, 2022

Results:

238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co

Comments

Yeast Media

Run: 221031

Nov 9, 2022

(mBq/kg)

<7.44

153.30

235.00

4.96

3.37

<9.99

64.44

70.98

<8.01

<1.50

(ppm / ppb / ppt)

<0.6 ppb

12.42 ppb

19.04 ppb

8.72 ppb

5.94 ppb

<2.46 ppb

2.08 ppm

2.29 ppm

Results:

7Be:

54Mn

228Ac:

(mBq/kg)

62.87

36.48

<5.27

<15.26

(ppm / ppb / ppt)

<3.75 ppb

REPAIR 07

SC-N
Natural K

172.0 g

6.798

Nov 16, 2022

Results:

238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co

Comments

Yeast Media

Run: 221116
221121

Nov 23, 2022

(mBq/kg)

5.53

4.00

<168.20

<3.61

<2.36

647.51

93.81

<4.21

<1.88

(ppm / ppb / ppt)

0.45 ppb

0.32 ppb

<13.62 ppb

<6.35 ppb

<0.58 ppb

20.91 ppm

3.03 ppm

Results:

7Be:

54Mn

228Ac:

(mBq/kg)

<31.89

1.49

1.83

<8.63

(ppm / ppb / ppt)

<2.12 ppb

REPAIR 08

SC-39
Refined K-39

168.2 g

6.937

Nov 23, 2022

Results:

238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co

Comments

Yeast Media

Run: 221123
221128

Nov 30, 2022

(mBq/kg)

<7.91

<122.60

<4.94

<5.19

64.43

43.19

<3.04

<1.66

(ppm / ppb / ppt)

<0.64 ppb

<9.93 ppb

<8.69 ppb

<1.28 ppb

2.08 ppm

1.4 ppm

Results:

7Be:

54Mn

228Ac:

(mBq/kg)

<27.12

<1.57

<9.54

(ppm / ppb / ppt)

<2.35 ppb

REPAIR 09

SC-N
Natural K
(Dec 5, 2022)

175.0 g

15.791

Dec 19, 2022

Results:

238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co

Comments

Yeast Media

Run: 221219

Jan 4, 2023

(mBq/kg)

2.22

3.45

<214.70

<2.17

<8.27

11179.00

610.50

<5.13

<4.29

(ppm / ppb / ppt)

0.18 ppb

0.28 ppb

<17.39 ppb

<3.82 ppb

<2.03 ppb

361.08 ppm

19.72 ppm

Results:

7Be:

54Mn

228Ac:

(mBq/kg)

<17.45

<4.56

<11.69

(ppm / ppb / ppt)

<2.88 ppb

REPAIR 10

SC-39
Refined K-39
(Dec 5, 2022)

183.8 g

13.833

Jan 4, 2023

Results:

238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co

Comments

Yeast Media

Run: 230104
230117

Jan 18, 2023

(mBq/kg)

<1.82

<74.75

<1.75

5.30

2.87

124.56

34.27

<1.36

<0.66

(ppm / ppb / ppt)

<0.15 ppb

<6.05 ppb

<3.08 ppb

1.3 ppb

0.71 ppb

4.02 ppm

1.11 ppm

Results:

7Be:

54Mn

228Ac:

(mBq/kg)

<14.99

<0.50

<5.51

(ppm / ppb / ppt)

<1.36 ppb

REPAIR 11

K-N
Natural K
(Nov 28, 2022)

106.4 g

7.055

May 17, 2023

Results:

238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co

Comments

Yeast Media

Run: 230517

May 24, 2023

(mBq/kg)

<17.90

461.40

375.70

<5.98

2.22

9.41

15847.00

948.80

19.72

7.27

<6.73

(ppm / ppb / ppt)

<1.45 ppb

37.37 ppb

30.43 ppb

<10.52 ppb

0.55 ppb

2.31 ppb

511.86 ppm

30.65 ppm

Results:

7Be:

54Mn

228Ac:

(mBq/kg)

<101.30

<15.94

<33.15

(ppm / ppb / ppt)

<8.15 ppb

In Progress and To Be Measured:

Sample Description

Manufacturer

Mass (g)

Live Time (days)

Counting Dates
(if applicable)

238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co

Comments

Next Sample

Results:

238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co

Comments

(mBq/kg)

(ppm / ppb / ppt)

Results:

7Be:

54Mn

228Ac:

(mBq/kg)

(ppm / ppb / ppt)