The Nuclear Emergency Response Headquarters has released a policy paper, “An interim policy on handling sewage treatment by-products in Fukushima Prefecture” (herein after referred to as the “Policy”) as per Annex-1. In applying the policy, the points described below should be noted, and consideration shall be given to the required actions such as controlling radiation exposure of workers in order to prevent health impairment for those workers at relevant workplaces pursuant to the Ordinance on Prevention of Ionizing Radiation Hazards (hereinafter referred to as the “Ionizing Radiation Ordinance”).
It should be noted that the same content of this notice has been sent to the Governors of Fukushima, Ibaraki and Tochigi Prefectures as per Annex-2.
Radioactivity concentration as high as 446,000 Bq/kg (total radioactivity of Cs-134 and Cs-137) has been detected from the dewatered sludge and related materials from sewage treatment plants in Fukushima Prefecture and cement and molten slug both using such dewatered sludge and related materials as shown in the attachment. In response to this fact, the following policy to handle those materials for the time being was formulated by the relevant office and ministers with advice from the Nuclear Safety Committee (NSC).
Dewatered sludge and related materials from sewage treatment plants shall be handled and managed properly according to its radioactivity concentration. It is important to continue the measurement of radioactivity concentration of the sludge to know the change of the situation in order to take appropriate actions.
When radioactivity concentration significantly higher than that measured in the past is detected from dewatered sludge and related materials, ways to manage the sludge and related materials will be discussed again.
Facility name | Municipality where facilities are located |
Date of analysis |
Analysis results of nuclides in the sludge (Bq/kg) |
Remarks | |||
---|---|---|---|---|---|---|---|
Cs-134 | Cs-137 | sum of Cs | I-131 | sludge | |||
Central Prefecture Purification Center |
Koriyama City |
30 Apr | 13,000 | 13,400 | 28,400 | --- | melted slag |
30 Apr | 165,000 | 169,000 | 334,000 | --- | |||
Horikawa Town Wastewater Treatment Plant |
Fukushimaa City |
2 May | 158,000 | 168,000 | 328,000 | 5,440 | |
4 May | 216,000 | 230,000 | 446,000 | 6,160 | |||
Yokozuka Treatment Plant |
Koriyamaa City |
3 May | 7,850 | 8,280 | 16,100 | 96 | sludge collected on 2 May |
3 May | 3,720 | 3,940 | 7,650 | 89 | sludge collected on 25 Apr | ||
Haramachi Daiichi Sewage Treatment Plant |
Minamisomaa City |
2 May | 4,560 | 4,820 | 9,380 | 92 | |
Northern Purification Center | Iwakia City | 2 May | 3,470 | 3,690 | 7,160 | 2,730 | |
Eastern Purification Center | Iwakia City | 2 May | 1,040 | 1,090 | 2,130 | 477 |
Facility name | Municipality where facilities are located | Date of analysis | Analysis results of nuclides in the sludge (Bq/kg) | Remarks | |||
---|---|---|---|---|---|---|---|
Cs-134 | Cs-137 | sum of Cs | I-131 | sludge | |||
North Prefecture Purification Center |
Kunimi Town |
2 May | 1,430 | 1,470 | 2,900 | 400 | |
Adatara Seiryu Center |
Nihonmatsu City |
4 May | 1,300 | 1,390 | 2,690 | 90 | |
Hayama Seiryu Center |
Sukagawa City |
3 May | ND | ND | ND | ND | sludge generated between Sep 2010 to 9 Apr 2011 |
3 May | 79 | 85 | 164 | 25 | sludge generated between 10 Apr 2010 to 2 May 2011 | ||
Ootakinemizu Environment Center |
Tamura City |
4 May | 769 | 798 | 1,570 | 322 | |
Shirakawa Urban Environment Center |
Shirakawa City |
2 May | 813 | 812 | 1,630 | 48 | |
Nishigo Village Oodaira Purification Center |
Nishigo Village |
3 May | 168 | 186 | 352 | ND | |
Aizuwakamatsu City Purification Plant |
Aizuwakamatsu City |
3 May | 1,280 | 1,330 | 2,610 | 61 | sludge immediately after dewatering |
3 May | 8,500 | 9,230 | 17,700 | 298 | sludge with chaff ripening outdoors long before the nuclear power plant accident | ||
Kitakata Purification Center |
Kitakata City |
3 May | 575 | 531 | 1,110 | 304 | |
Taijima Urban Environment Center |
Minamiaizu Town |
3 May | 25 | 37 | 61 | ND | |
Central Purification Center |
Iwaki City |
3 May | 857 | 898 | 1,750 | 448 | sludge |
35,700 | 36,800 | 72,500 | 339 | soot and dust * | |||
17,400 | 18,300 | 35,700 | 215 | cinder generated after the nuclear power plant accident | |||
ND | ND | ND | ND | cinder generated before the nuclear power plant accident * |
* These were generated by incinerating sludge from the four wastewater treatment plants (Eastern, Northern, Southern and Central) in Iwaki City.
ND: not detected
Facility name | Municipality where facilities are located |
Date of analysis |
Analysis results of nuclides in airborne dust (Bq/m3) |
|||
---|---|---|---|---|---|---|
Cs-134 | Cs-137 | sum of Cs | I-131 | |||
Horikawa Town Wastewater Treatment Plant |
Fukushima City | 2 May | windward | ND | ND | ND |
downwind | ND | ND | ND | |||
4 May | windward | ND | ND | ND | ||
downwind | ND | ND | ND | |||
Yokozuka Treatment Plant | Koriyama City | 3 May | windward | ND | ND | ND |
downwind | ND | ND | ND | |||
Haramachi Daiichi Sewage Treatment Plant |
Minamisoma City | 2 May | windward | ND | ND | ND |
downwind | ND | 0.721 | ND | |||
Northern Purification Center | Iwaki City | 2 May | windward | ND | ND | ND |
downwind | ND | ND | ND | |||
Eastern Purification Center | Iwaki City | 2 May | windward | ND | ND | ND |
downwind | ND | ND | ND |
ND: not detected
Facility name | Municipality where facilities are located |
Date of analysis |
Analysis results of nuclides in airborne dust (Bq/m3) |
|||
---|---|---|---|---|---|---|
measurement point | Cs-134 | Cs-137 | I-131 | |||
North Prefecture Purification Center |
Kunimi Town | 2 May | windward | ND | ND | ND |
downwind | ND | ND | ND | |||
Adatara Seiryu Center | Nihonmatsu City | 4 May | windward | ND | ND | ND |
downwind | ND | ND | ND | |||
Hayama Seiryu Center | Sukagawa City | 3 May | windward | ND | ND | ND |
downwind | ND | ND | ND | |||
Ootakinemizu Environment Center |
Tamura City | 4 May | windward | ND | ND | ND |
downwind | ND | ND | ND | |||
Shirakawa Urban Environment Center | Shirakawa City | 2 May | windward | ND | 0.922 | ND |
downwind | ND | 0.698 | ND | |||
Nishigo Village Oodaira Purification Center | Nishigo Village | 3 May | windward | ND | ND | ND |
downwind | ND | ND | ND | |||
Aizuwakamatsu City Purification Plant |
Aizuwaka- matsu City |
3 May | within the site | ND | ND | ND |
Kitakata Purification Center | Kitakata City | 3 May | within the site | ND | ND | ND |
Tajima Urban Environment Center | Minamiaizu City | 3 May | windward | ND | ND | ND |
downwind | ND | ND | ND | |||
Central Purification Center | Iwaki City | 3 May | windward | ND | ND | ND |
downwind | ND | ND | ND |
*There is only one measurement point each for the Aizuwakamatsu City Purification Plant and the Kitakata Purification Center.
ND: not detected
Facility name | Municipality where facilities are located |
Date of analysis |
Analysis results of nuclides in airborne dust (Bq/m3) |
|||
---|---|---|---|---|---|---|
measurement point | Cs-134 | Cs-137 | I-131 | |||
Tamanoi Daini | Otama Village | 4 May | windward | ND | ND | ND |
downwind | ND | ND | ND | |||
Motonuma |
Shirakawa City |
2 May | windward | ND | 0.643 | ND |
downwind | ND | ND | ND | |||
Habuto | Nishigo Village | 3 May | windward | ND | ND | ND |
downwind | ND | ND | ND | |||
Tokorozawa | Yanaizu Town | 4 May | windward | ND | ND | ND |
downwind | ND | ND | ND |
* No analysis of radionuclides in airborne dust was undertaken because no sludge was sampled at the three facilities (Furumachi (Minamiaizu Town), Kinosaki (Sukagawa City) and Kusano (Iitate Village)).
In response to the accident at the Fukushima Daiichi Nuclear Power Plant associated with the Great East Japan Earthquake, the Nuclear Emergency Response Headquarters released a policy paper, “ An interim policy on handling sewage treatment by-products in Fukushima Prefecture” on 12 May 2011, as per the Annex-1.
Based on this policy, it has been decided to apply the Ordinance on Prevention of Ionizing Radiation Hazards (hereinafter referred to as the “Ionizing Radiation Ordinance”) in assigning workers handling by-products from sewage treatment as described below. The contents and actions in this notification shall be made known to all the municipalities within each prefecture respectively.
Facility name | Municipality where facilities are located |
Date of analysis |
Analysis results of radionuclides in sludge (Bq/kg) |
Remarks | |||
---|---|---|---|---|---|---|---|
Cs-134 | Cs-137 | sum of Cs | I-131 | ||||
Central Prefecture Purification Center |
Koriyama City | 30 Apr | 13,000 | 13,400 | 26,400 | --- | sludge |
30 Apr | 165,000 | 169,000 | 334,000 | --- | molten slag | ||
Horikawa Town Wastewater Treatment Plant | Fukushima City | 2 May | 158,000 | 168,000 | 326,000 | 5,440 | |
4 May | 216,000 | 230,000 | 446,000 | 6,160 | |||
Yokozuka Treatment Plant | Koriyama City | 3 May | 7,860 | 8,280 | 16,100 | 96 | sludge sampled on 2 May |
3 May | 3,720 | 3,940 | 7,660 | 69 | sludge sampled on 25 Apr | ||
Aizuwakamatsu City Purification Plant |
Aizuwakamatsu City |
3 May | 1,280 | 1,330 | 2,610 | 61 | sludge immediately after dewatering |
3 May | 8,500 | 9,230 | 17,700 | 298 | sludge with chaff ripening outdoors long before the nuclear power plant accident | ||
Central Purification Center | Iwaki City | 3 May | 857 | 896 | 1,750 | 446 | sludge |
35,700 | 36,800 | 72,500 | 339 | soot and dust * | |||
17,400 | 18,300 | 35,700 | 215 | cinder generated after the nuclear power plant accident * | |||
ND | ND | ND | ND | cinder generated before the nuclear power plant accident * |
* Those were generated by incinerating sludge from the four wastewater treatment plants (Eastern, Northern, Southern and Central) in Iwaki City
ND: not detected
Facility name | Date of sampling | Type of sample | Total of Cs-134 and Cs-137 (Bq/kg) |
---|---|---|---|
Sewage Resourcing Plant (Mobara, Utsunomiya City) |
2 May | incinerated ash | 32,000 |
Facility name | Date of sampling | Type of sample | Radioactivity (Bq/kg) | |
---|---|---|---|---|
Radioactive Iodine |
Radioactive cesium |
|||
Naka-Kuji Purification Center | 3 May | dewatered sludge | 290 | 493 |
3 May | incinerated ash | 120 | 17,020 |