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The measurement situation of radiological density, air dose in Resources and Waste Recycling Bureau

  The measurement situation of radiological density, air dose in garbage destruction by fire factory and landfill

  The air dose measurement (the Mike Rothe pot investigation) at use of citizen point

  The measurement situation of the radiological density of green compost

  ・Radiological concentration measurement situation nitsu of activated carbon of deodorant device of resources sorting center and broadcast transportation officeBe

  The measurement situation of radiological density in industrial waste incineration facilities

The measurement situation of radiological density, air dose in garbage destruction by fire factory and landfill

◆Summary of radiation measures◆

 In Yokohama-shi, we perform radiation measures in landfill and destruction by fire factory until now (as for the details, please see this).
 Radioactive material is not detected by drainage in landfill, and air dose is at the same level as result of a measurement of other points in the city, too.

◆Result of a measurement◆

 Destruction by fire ash occurring in four garbage destruction by fire factories operating for safe confirmation now in the city in Yokohama-shi and inflow water of landfill,
We measure the radiological density of discharge water.
 In addition, air dose measures about destruction by fire factory (hihaitokorisakugyojoshofukin) and Minamihonmoku landfill (site border).

・Garbage destruction by fire factory
 
Tsuzuki factory / Tsurumi factory / Asahi factory / Kanazawa factory
 
The radiological density of destruction by fire ash which occurred in garbage destruction by fire factory is less than 100Bq/kg (as for the inning standard that country showed 8,000Bq/kg).
・Because "the non-detection" of radiological density continued about effluent gas, agglomeration deposition sludge, reuse water and discharge water, we finished investigation.
               
・Landfill
 
Minamihonmoku landfill / Shinmeidai disposal place
 

All the circumference of Minamihonmoku landfill is surrounded by building a breakwater with impermeable function, and it is in structure that inland waters of disposal ground leak, and does not appear.
 
Radioactive material is not detected from inflow water and discharge water in drainage handling of Minamihonmoku landfill facility to treat inland waters appropriately.
・Because "the non-detection" of radiological density continued about Shinmeidai disposal place, we finished investigation in 2015.

 

◆Method for measurement◆

    1. Radiological density 
      (1) Sampling method
      A destruction by fire ash and drainage sludge
        "Radioactivity concentration is based in method for measurement guidelines" (Ministry of the Environment, March, 2013)
     
  • Destruction by fire ash: We gather using scoops and dispense in sample container (polybottle) after the mixture.
  • Drainage sludge: We gather in sample container (polybottle) using saideiki.
      i drainage and water of public area of the sea
        "Radioactivity concentration is based in method for measurement guidelines" (Ministry of the Environment, March, 2013)
        We collect water in sample container (polybottle) using ladle, bucket.
       
      u effluent gas
        We are based based on JIS Z8808 on "radioactivity investigation, assay tentativeness manuals such as refuse" (National Institute for Environmental Studies others, November 11, 2011)
       We aspirate equal speed from existing "baijin" established in chimney flue wall surface measurement hole and gather by sampling device comprised of cylinder filter paper, liquid sampling department (in pin jar) and activated carbon.
       
     
Effluent gas sampling device
       
      (2) Method for measurement
       We measure Ministry of Education, Culture, Sports, Science and Technology radioactivity assay series No. 7 using germanium semiconductor detector according to "gamma ray spectrometry with germanium semiconductor detector" in August, 1992 (3 *).
       
    2. Air dose
      (1) Method for measurement
        "Radioactivity concentration is based in method for measurement guidelines" (Ministry of the Environment, December, 2011)
     
  • Garbage destruction by fire factory: We measure at hihaitokorisakugyojosho, 1m above the ground
  • Minamihonmoku landfill: We measure site borders at eight spots, 1m above the ground
      (2) Measuring equipment
         NaI(TI) scintillation survey meter TCS-172B made in Hitachi Aloka Medical Corporation
         (measurement range: 0.01-30μSv/h)
     

   [2011 from July through November]
         Advanced GM survey meter ASM-990 made in FLUKE-Biomedical company
         (measurement range: 0.01-800μSv/h)

   

 

[remarks]
 Unevenness comes out to measurements even if we measured the same radiation dose by the measurement of radiation dose with survey meter.
 ・We receive influence with geological feature of measurement point or neighboring buildings.
 ・Measurements of radiation change by wind or the rain even if they measure at the same place.

 

The air dose measurement (the Mike Rothe pot investigation) at use of citizen point

   To confirm existence yes or no of "Mike Rothe pot" about point that citizen uses by visits in facility which Resources and Waste Recycling Bureau has jurisdiction over,
  We measured air dose in 2011.

Result of a measurement◆
   ・ List of air dose measurement (the Mike Rothe pot investigation) results at citizen's use point in Resources and Waste Recycling Bureau jurisdiction facility
◆Press release documents◆
    About result of a measurement of radiation dose in Resources and Waste Recycling Bureau jurisdiction facility (PDF: 163KB)
 

The measurement situation of the radiological density of green compost

  We carried out from 2011 through 2012. 
      Result of a measurement to page of wastes measures section

 

About the radiological concentration measurement situation of activated carbon of deodorant device of resources sorting center and broadcast transportation office

      We carried out from 2012 through 2013.
      Result of a measurement to page of Operations Section

 

The measurement situation of radiological density in industrial waste incineration facilities

      We carried out in 2011.
      Result of a measurement to page of industrial waste measures section
  
 

※Please refer to page of Environmental Planning Bureau for the measurement situation of radiological density in sewer facility (sludge exploitation of resources center).