General Information

Radionuclides

Radionuclide Concentration, Fly Ash, Bq/kg
Element
Range
Weighted
average1
Exemption
Level2
226Ra
55 – 264
154
1,000
232Th
46 – 240
132
40K
105 – 628
295
10,000
Radionuclide Concentration, Bottom Ash, Bq/kg
226Ra
37 – 237
115
1,000
232Th
28 – 212
96
40K
66 – 519
222
10,000

1. Sum of multiplying the average for a given origin in the relative percent of coal ash from that origin in a given year.
2. Material whose radionuclides concentrations meet these values, is exempted from regulatory control, according to IAEA (International Atomic Energy Agency Safety Guide No. RS-G-1.7, 2004.

Source: Measurements done in Soreq-NRC (Nuclear Research Center) for NCAB’ coal ash samples of individual sources (coal mines).

Radionuclides Concentrations (Bq/kg) in coal ash, 2016

Fly Ash
Country
South Africa
Colombia
Russia
Range
Weighted
average
Stdev
Element
Value
Min
Ave
Max
Min
Ave
Max
226Ra
228 84 88 96 137 140 143 84-228 140 53
232Th
205 50 53 58 64 71 78 50-205 96 56
40K
133 392 437 492 418 459 500 133-500 371 126
Bottom Ash
226Ra
173 57 64 70 165 57-173 125 57
232Th
160 34 40 48 77 34-160 82 52
40K
115 285 326 371 406 115-406 303 113

Radionuclides Concentrations (Bq/kg) in coal ash, 2015

Fly Ash
Country
South Africa
Colombia
Australia
Russia
Range
Weighted
average
Stdev
Element
Min
Ave
Max
Min
Ave
Max
Value
Min
Ave
Max
226Ra
186 221 256 86 104 140 99 109 135 161 86-256 153 57
232Th
175 201 227 50 75 119 97 76 103 131 50-227 127 59
40K
136 142 147 384 436 495 139 386 474 563 136-563 332 164
Bottom Ash
226Ra
196 207 218 62 81 103 86 59 75 91 59-218 121 61
232Th
170 191 212 37 59 81 81 40 52 64 37-212 100 64
40K
86 98 109 145 299 465 145 373 446 519 86-519 266 153

Radionuclides Concentrations (Bq/kg) in coal ash, 2014

Fly Ash
Country
South Africa
Colombia
Australia
Russia
Range
Weighted
average
Stdev
Element
Min
Ave
Max
Min
Ave
Max
Value
Min
Ave
Max
226Ra
191 228 264 82 104 151 103 119 122 124 82-264 53 57
232Th
176 208 240 48 68 121 100 75 76 77 49-240 121 63
40K
171 182 193 283 401 606 214 509 528 548 171-606 352 153
Bottom Ash
226Ra
153 195 237 57 62 76 79 67 79 91 57-237 115 58
232Th
138 172 207 34 38 44 79 43 52 62 34-207 91 57
40K
99 118 138 202 297 411 175 225 321 418 99-418 239 108

Radionuclides Concentrations (Bq/kg) in coal ash, 2013

Fly Ash
Country
South Africa
Colombia
Australia
Russia
Range
Weighted
average
Stdev
Element
Min
Ave
Max
Min
Ave
Max
Value
Min
Ave
Max
226Ra
186 206 219 78 87 104 90 85 111 137 78-219 141 55
232Th
170 182 215 47 54 77 93 60 67 75 47-215 112 61
40K
130 175 204 350 416 462 209 463 483 503 730-503 319 136
Bottom Ash
226Ra
145 177 201 45 56 63 70 70 88 106 45-201 113 59
232Th
134 159 190 28 33 37 67 54 59 64 28-190 92 59
40K
116 123 134 185 271 354 147 403 420 436 116-436 234 116

Radionuclides Concentrations (Bq/kg) in coal ash, 2012

Fly Ash
Country
South Africa
Colombia
Australia
Indonesia
Russia
Range
Weighted
average
Stdev
Element
Min
Ave
Max
Min
Ave
Max
Value
Value
Value
226Ra
193 213 232 82 95 100 93 76 129 76-232 153 57
232Th
178 191 217 52 65 73 92 47 106 47-217 129 59
40K
123 172 238 372 401 457 210 400 383 123-457 286 116
Bottom Ash
226Ra
144 170 186 50 57 74 88 n.d 84 50-186 114 52
232Th
135 156 170 35 45 43 85 n.d 58 35-170 99 55
40K
80 94 114 244 247 349 179 n.d 460 80-460 217 122

Radionuclides Concentrations (Bq/kg) in coal ash, 2011

Fly Ash
Country
South Africa
Colombia
Australia
Indonesia
Russia
Range
Weighted
average
Stdev
Element
Value
Min
Ave
Max
Value
Min
Ave
Max
Min
Ave
Max
226Ra
216
81
92
101
94
58
60
62
114
134
153
58-216
141
45
232Th
207
46
54
74
92
53
54
54
72
74
76
46-207
114
46
40K
147
251
432
513
117
488
489
489
464
470
475
117-513
321
148
Bottom Ash
226Ra
188
56
65
84
70
46
46
47
71
75
80
46-188
110
40
232Th
167
33
38
51
63
42
42
42
35
43
51
33-167
87
39
40K
102
167
283
368
97
365
370
375
180
274
368
97-375
211
111

Radionuclides Concentrations (Bq/kg) in coal ash, 2010

Fly Ash
Country
South Africa
Colombia
Australia
Indonesia
Russia
Range
Weighted
average
Stdev
Element
Value
Min
Ave
Max
Value
Min
Ave
Max
Min
Ave
Max
226Ra
203
82
89
101
99
58
61
63
100
119
138
58-203
133
42
232Th
199
47
56
65
93
48
52
55
74
88
115
48-199
115
46
40K
142
250
416
516
139
385
447
509
400
436
484
139-516
315
145
Bottom Ash
226Ra
155
58
66
81
69
37
42
47
86
87
88
37-155
99
35
232Th
137
35
40
44
67
29
38
47
60
63
65
29-137
80
33
40K
112
170
329
439
104
231
297
364
387
394
402
112-439
250
132

Radionuclides Concentrations (Bq/kg) in coal ash, 2009

Fly Ash
Country
South Africa
Colombia
Australia
Indonesia
Russia
Range
Weighted
average
Stdev
Element
Min
Ave
Max
Min
Ave
Max
Value
Value
Min
Ave
Max
226Ra
179
193
220
87
89
91
88
55
101
101
102
55-220
135
56
232Th
154
171
198
49
58
67
84
55
74
79
84
49-198
115
54
40K
133
178
206
337
394
451
198
463
401
428
456
133-463
299
133
Bottom Ash
226Ra
89
133
183
53
66
79
80
n.d
71
78
85
53-183
109
40
232Th
80
117
154
36
52
67
80
n.d
50
63
77
36-154
95
38
40K
66
93
114
278
325
372
108
n.d
224
253
282
66-372
180
105

Radionuclides Concentrations (Bq/kg) in coal ash, 2008

Fly Ash
Country
South Africa
Colombia
Aus.
Indonesia
Can.
Russia
Range
Weighted
average
Stdev
Element
Min
Ave
Max
Min
Ave
Max
Val
Min
Ave
Max
Val
Min
Ave
Max
226Ra
215
218
221
84
90
97
109
76
84
93
178
104
104
104
76-221
158
7
232Th
210
222
233
61
67
73
101
64
77
90
106
73
76
78
61-233
152
13
40K
142
166
190
258
379
501
153
364
388
413
337
264
403
542
142-542
260
165
Bottom Ash
226Ra
167
173
180
49
51
52
77
65
155
n.d
n.d
n.d
49-180
118
58
232Th
146
159
172
37
38
40
75
66
102
n.d
n.d
n.d
49-180
108
52
40K
116
123
130
238
296
354
129
317
283
n.d
n.d
n.d
116-354
188
99

Radionuclides Concentrations (Bq/kg) in coal ash, 2007

Fly Ash
Country
South Africa
Colombia
Australia
Indonesia
Russia
Range
Weighted
average
Stdev
Element
Min
Ave
Max
Value
Value
Value
Min
Ave
Max
226Ra
205
205
206
122
n.d
142
104
129
153
104-206
173
42
232Th
189
189
189
89
n.d
128
77
94
111
77-189
152
48
40K
148
188
227
536
n.d
105
264
370
476
105-536
251
175
Bottom Ash
226Ra
148
n.d
n.d
n.d
74
92
109
74-148
142
37
232Th
143
n.d
n.d
n.d
55
74
93
55-143
135
44
40K
120
n.d
n.d
n.d
260
303
346
120-346
141
114

Radionuclides Concentrations (Bq/kg) in coal ash, 2006

Fly Ash
Country
South Africa
Colombia
Australia
Indonesia
Russia
Range
Weighted
average
Stdev
Element
Min
Ave
Max
Min
Ave
Max
Value
Value
Value
226Ra
207
230
251
101
136
159
n.d
97
126
101-251
181
59
232Th
190
208
239
60
102
132
n.d
95
76
60-239
157
64
40K
154
175
210
301
450
628
n.d
510
448
154-628
305
174
Bottom Ash
226Ra
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
232Th
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
40K
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d

Radionuclides Concentrations (Bq/kg) in coal ash, 2005

Fly Ash
Country
South Africa
Colombia
Australia
Indonesia
Russia
Range
Weighted
average
Stdev
Element
Min
Ave
Max
Min
Ave
Max
Value
Value
Min
Ave
Max
226Ra
98
181
234
97
116
135
n.d
109
n.d
n.d
n.d
97-234
164
60
232Th
56
159
218
64
83
102
n.d
111
n.d
n.d
n.d
56-218
141
70
40K
144
220
368
373
389
404
n.d
223
n.d
n.d
n.d
144-404
253
119
Bottom Ash
226Ra
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
232Th
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
40K
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d

* n.d- no data.
* Average- sum of the values of coal ash from various source (coal mines) per origin (country), divided in the number of sources.
* Weighted average- sum of multiplying the average for a given origin in the relative percent of coal ash from that origin in a given year.