The Series of Environmental Radioactivity Measuring Methods
AP-E(No.24)

Preparation of Samples for Gamma-ray
Spectrometry in Emergencies

Amendment of March 2019
Radiation Monitoring Division
Radiation Protection Department
The Secretariat of
Nuclear Regulation Authority

Table of Contents
Chapter 1 Introduction.............................................................................................................................1
Chapter 2 Concept of Preparation of Samples in Emergencies .................................................................3
2.1 Emergency monitoring ....................................................................................................................3
2.2 Samples to be measured ..................................................................................................................4
2.3 Contamination prevention measures................................................................................................5
2.4 Preparation method ..........................................................................................................................92.5 Quantifiable levels .........................................................................................................................11
2.6 Sample preparation ........................................................................................................................14
Chapter 3 Glossary ..................................................................................................................................17
Chapter 4 Atmosphere.............................................................................................................................20
4.1 Equipment, tools, etc.to be needed ................................................................................................20
4.2 Precautions for carrying in samples ...............................................................................................20
4.3 Sample preparation method ...........................................................................................................21
4.4 Storage of samples .........................................................................................................................24
4.5 Pretreatment methods for long (continuous) filters and large filters and their characteristics .......25
Chapter 5 Fallout and precipitation .........................................................................................................27
5.1 Equipment, tools, etc. to be needed................................................................................................27
5.2 Precautions for carrying in samples ...............................................................................................27
5.3 Sample preparation method ...........................................................................................................28
5.4 Storage of samples .........................................................................................................................29
Chapter 6 Drinking water and inland water ............................................................................................31
6.1 Equipment, tools, etc. to be needed................................................................................................31
6.2 Precautions for carrying in samples ...............................................................................................32
6.3 Sample preparation method ...........................................................................................................32
6.4 Storage of samples .........................................................................................................................35
Chapter 7 Seawater .................................................................................................................................36
7.1 Equipment, tools, etc. to be needed................................................................................................36
7.2 Precautions for carrying in samples ...............................................................................................36
7.3 Sample preparation method ...........................................................................................................37
7.4 Storage of samples .........................................................................................................................38
Chapter 8 Soil..........................................................................................................................................39
8.1 Equipment, tools, etc. to be needed................................................................................................39
8.2 Precautions for carrying in samples ...............................................................................................39

8.3 Sample preparation method ...........................................................................................................40
8.4 Pretreatment of watery samples .....................................................................................................42
8.5 Calculation of dry soil rate ............................................................................................................43
8.6 Calculation of deposits ..................................................................................................................44
Chapter 9 Vegetables ...............................................................................................................................45
9.1 Equipment, tools, etc. to be needed................................................................................................45
9.2 Precautions for carrying in samples ...............................................................................................46
9.3 Sample preparation method ...........................................................................................................46
9.4 Storage of samples .........................................................................................................................52
Chapter 10 Fruit ......................................................................................................................................53
10.1 Equipment, tools, etc. to be needed..............................................................................................53
10.2 Precautions for carrying in samples .............................................................................................53
10.3 Sample preparation method .........................................................................................................54
10.4 Storage of samples .......................................................................................................................58
Chapter 11 Tea leaves ..............................................................................................................................59
11.1 Equipment, tools, etc. to be needed ..............................................................................................59
11.2 Precautions for carrying in samples .............................................................................................59
11.3 Sample preparation method ..........................................................................................................60
11.4 Storage of samples .......................................................................................................................62
Chapter 12 Grains ...................................................................................................................................6412.1 Equipment, tools, etc. to be needed..............................................................................................6412.2 Precautions for carrying in samples .............................................................................................6412.3 Sample preparation method .........................................................................................................65
12.4 Storage of samples .......................................................................................................................67
Chapter 13 Peas and beans ......................................................................................................................68
13.1 Equipment, tools, etc. to be needed..............................................................................................68
13.2 Precautions for carrying in samples .............................................................................................68
13.3 Sample preparation method .........................................................................................................69
13.4 Storage of samples .......................................................................................................................72
Chapter 14 Mushrooms ...........................................................................................................................73
14.1 Equipment, tools, etc. to be needed..............................................................................................73
14.2 Precautions for carrying in samples .............................................................................................73
14.3 Sample preparation method .........................................................................................................74
14.4 Storage of samples .......................................................................................................................77
Chapter 15 Seaweeds ..............................................................................................................................78

15.1 Equipment, tools, etc. to be needed..............................................................................................78
15.2 Precautions for carrying in samples .............................................................................................78
15.3 Sample preparation method .........................................................................................................79
15.4 Storage of samples .......................................................................................................................82
Chapter 16 Meats ....................................................................................................................................83
16.1 Equipment, tools, etc. to be needed..............................................................................................83
16.2 Precautions for carrying in samples .............................................................................................83
16.3 Sample preparation method .........................................................................................................84
16.4 Storage of samples .......................................................................................................................87
Chapter 17 Cow’s milk............................................................................................................................88
17.1 Equipment, tools, etc. to be needed..............................................................................................88
17.2 Precautions for carrying in samples .............................................................................................88
17.3 Sample preparation method .........................................................................................................89
Chapter 18 Dairy products ......................................................................................................................92
18.1 Equipment, tools, etc. to be needed..............................................................................................92
18.2 Precautions for carrying in samples .............................................................................................92
18.3 Sample preparation method .........................................................................................................93
18.4 Storage of samples .......................................................................................................................96
Chapter 19 Eggs ......................................................................................................................................97
19.4 Storage of samples .....................................................................................................................100
Chapter 20 Seafood ...............................................................................................................................101
20.1 Equipment, tools, etc. to be needed............................................................................................101
20.2 Precautions for carrying in samples ...........................................................................................102
20.3 Sample preparation method .......................................................................................................102
20.4 Storage of samples .....................................................................................................................111
Chapter 21 Indicator organisms (including pasture plants) ...................................................................112
21.1 Equipment, tools, etc. to be needed............................................................................................11221.2 Precautions for carrying in samples ...........................................................................................113
21.3 Sample preparation method .......................................................................................................113
21.4 Storage of samples .....................................................................................................................117
Explanation ............................................................................................................................................119
Explanation A Calculation of quantifiable levels ..............................................................................121
Explanation B Results of study on adsorption of radionuclides on measurement container wall ....126
Appendix ................................................................................................................................................137

Appendix 1 Equipment, tools, reagents, etc. to be made available and ready for use at all times ...139
Appendix 2 Marinelli beaker and inner bag for Marinelli beaker ....................................................141
Appendix 3 Small container ..............................................................................................................143
Information.............................................................................................................................................145
Information 1 Concept of implementation items and content of emergency monitoring ..................147
Information 2 Handling high-concentration samples .......................................................................150
Information 3 Long-term storage methods of samples .....................................................................152
Information 4 Matters to be noted when discarding samples ...........................................................154
Information 5 State of cesium present in inland water .....................................................................155
Information 6 Concept of soil monitoring ........................................................................................157
Information 7 Masters to be noted when washing vegetables, etc....................................................162
Reference .............................................................................................................................................163

Chapter 1 Introduction
Emergency monitoring refers to environmental radiation monitoring that is to be conductedin cases of actual or potential abnormal release of radioactive materials or radiation, as
stipulated by the Nuclear Emergency Preparedness and Response Guidelines (hereinafterreferred to as the “Nuclear Emergency Guidelines”) issued by the Nuclear Regulation
Authority (NRA) in 2018 (Reference 1). According to the Nuclear Emergency Guidelines,
preparation for emergency monitoring is to be made during a state of alert and the actual
monitoring is to begin when the relevant facility enters a state of emergency. The Nuclear
Emergency Guidelines also states that emergency monitoring is divided into three stages,
namely, initial stage monitoring for the determination of appropriate protective measures,
middle stage monitoring for the evaluation and identification of overall impact on thesurroundings, and recovery stage monitoring. In addition, emergency monitoring is discussed
in the “Emergency Monitoring” (supplementary reference material of the Nuclear Emergency
Preparedness and Response Guidelines) issued by the Radiation Monitoring Division,
Radiation Protection Department, NRA in 2017 (Reference 2). Matters addressed in the“Emergency Monitoring” include the purpose of emergency monitoring, implementation
system, and monitoring items. The Preparation of Samples for Gamma-ray Spectrometry in
Emergencies (hereinafter referred to as “this document”) provides the methods of preparationof samples in initial stage monitoring, but is also useful in cases where the investigation
conducted in the initial stage monitoring is to be continued in the middle stage and recovery
stage monitoring.
The published radioactivity measurement series that concern sample preparation andpretreatment methods include Radioactivity Measurement Series No. 13 Pretreatment ofSamples for Instrumental Analysis using Germanium Semiconductor Detector, etc. (Reference3) and Radioactivity Measurement Series No. 16 Method for Sampling Environmental
Materials (Reference 4). This document was published in August 1992 as the Radioactivity
Measurement Series No. 24 that describes the method to prepare samples for gamma-ray
spectrometry in emergencies, specifically targeting several-dozen types of environmental
samples. The background of establishing this document goes back to the accident at the
Chernobyl Nuclear Power Plant that occurred in 1986 and associated surveys on the effectsof radioactivity. This event triggered discussions on the need for swift determination of
measures against radiation and evaluation of dose equivalent in emergency situations, and thedemand for establishing a manual on emergency monitoring.
Immediately following the accident at the Fukushima Daiichi Nuclear Power Plant in the
Great East Japan Earthquake that struck on March 11, 2011 (hereinafter referred to as the“Fukushima Daiichi Nuclear Accident”), gamma-ray spectrometry using germanium
detectors was widely utilized in emergency monitoring at various analysis institutions.
However, it was found that many of the laboratories which participated in the monitoring
program did not have sufficient experience regarding radioactivity analysis under nuclear
emergency, especially how to handle environmental samples collected under suchcircumstances.

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This document describes several issues concerning measurement of radioactive materials undernuclear emergencies, which include selection of samples, contamination prevention measures,
sample preparation methods, and quantifiable levels, and summarizes how to address eachissue. This revision includes additional specific descriptions and photographs, together witharrangements for broadly sharing the knowledge gained through the experience associated with
the Fukushima Daiichi Nuclear Accident and actual cases of emergency monitoring.
The preparation methods provided in this document prescribe standard operational methods
aimed at making the measurement results uniform. Therefore, autonomous monitoring
conducted by municipalities and research institutions in emergencies is expected to conform tothis document in principle. However, in regards to monitoring performed for a specific purpose,
this does not preclude the use of preparation methods other than those provided in thisdocument, so long as the preparation method is appropriate for the said purpose.
The content of this document is to be revised as necessary, according to the status ofrevision of the basal documents (the Nuclear Emergency Guidelines and the supplementaryreference material of the Nuclear Emergency Preparedness and Response Guidelines) and theadvancement in monitoring technologies and techniques.

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Chapter 2 Concept of Preparation of Samples in Emergencies
2.1 Emergency monitoring
Emergency monitoring is addressed in detail in the “Emergency Monitoring”(supplementary reference material of the Nuclear Emergency Preparedness and Response
Guidelines) issued by the Radiation Monitoring Division, Radiation Protection Department,
NRA in 2017 (Reference 2). The “Emergency Monitoring” specifies two types of monitoring
items related to this document, namely, the measurement of concentration of radioactive
materials in the atmosphere and the measurement of concentration of radioactive materials inenvironmental samples.
2.1.1 Measurement of concentration of radioactive materials in the atmosphere
The main purposes of this measurement are to collect information about the status ofenvironmental radiation due to a nuclear emergency and to provide the information toevaluate the effects of the radiation on the local residents and the environment. In thismeasurement, spreading of radioactive materials is checked using a monitoring system andthe monitoring data is utilized for the evaluation of exposure. The normal means of monitoringis an atmosphere monitoring device (enables ascertaining the temporally continuous changes
in concentration of radioactive materials in the atmosphere) or an iodine sampler with anautomatic sample changer (continuously samples gaseous and particulate iodine whileregularly replacing the filter and active carbon cartridge).
2.1.2 Measurement of concentration of radioactive materials in environmental samples
Environmental samples covered in this document are classified into precipitation, soils, andfood anddrinks. Soils include soil, inland water, seawater, river sediment, lake sediment, sea
sediment, and indicator organisms.
(1) Measurement of concentration of radioactive materials in soils

The main purposes of this measurement are to check the spreading of radioactive materials
deposited on the ground and to ascertain their nuclide composition. For that reason, in the stageof initial response to a nuclear emergency, soil is sampled and analyzed or measured without
delay for areas near the monitoring stations at which an ambient radiation dose rate exceeds the
Operational Intervention Level 2 (OIL2) *1 first.
(2) Measurement of concentration of radioactive materials in food and drinks

The main purposes of this measurement are to provide the materials for determining thenecessity for implementing protective measures and for evaluating the effects of radiation on
the local residents and the environment due to a nuclear emergency.

*1: The standard at which intake of regional produces is restricted and residents are temporarily relocated within about one

week after a nuclear emergency for the purpose of preventing exposure due to radiation from the ground surface,
inhalation of radioactive materials that were released back into the air, and careless oral intake of contaminated food anddrinks (corresponds to an ambient radiation dose rate of 20 μSv/h as measured at a height of 1 m from the ground).

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(a) Before commencing inspection of radioactive materials in food and drinks based on
OIL6 *2
When release of radioactive materials is confirmed for a region, to ascertain the effectsof the radioactive materials on drinking water, potable water supplied from the sources
available in the region is to be sampled and analyzed without delay. This is usually done
for water supplied from waterworks and small water supply systems that are possibly
contaminated with radioactive materials.
(b) Inspection of radioactive materials in food and drinks based on OIL6
For a region at which the ambient radiation dose rate exceeds 0.5 μSv/h, the concentrationof radioactive materials is to be measured for the food and drinks produced in the region.

NuclidesTable 2.1 OIL6 (initial set values)*3
Drinking water, cow’s milk,
Vegetables, grains, meat,eggs,
dairy products
fish, otherRadioactive iodine

300 Bq/kg

2,000 Bq/kg※

Radioactive cesium

200 Bq/kg

500 Bq/kg※ Applicable to vegetables excluding root vegetables and potatoes.
Regarding the measurement to be performed in order to determine the necessity of
implementing protective measures based on OIL6, attention needs to be paid to obtaining
the measurement results by the time when the result of emergency monitoring is required,taking into account the time required formeasurements that vary depending on the nuclide.
Information 1 describes the approach to OIL6 and the measuring time in gamma-ray
spectrometry in emergencies.
2.2 Samples to be measured
In the previous version of this document, the samples to be measured were the atmosphere,
fallout and precipitation, drinking water and source water, cow’s milk, dairy products, leaf
vegetables, seaweeds, fish, seawater, and soil, referring to the previous Guide forEnvironmental Radiation Monitoring in Emergency (Nuclear Safety Commission) and otherrelevant documents. They also included grains, peas and beans, meats and eggs that would
become necessary for environmental radiation monitoring. In addition, the previous version
covered the samples that are likely to undergo the same preparation method as those for the
samples listed above. In this version, the samples to be measured are the environmental
samples listed in the previous version of this document as well as the environmental samples
listed in the “Emergency Monitoring” (Reference 2). In addition, fruit is added to the samples
to be measured, based on the experience from the Fukushima Daiichi Nuclear Accident.
Further, in this version, the samples are classified into 18 groups taking into account theircharacteristics and preparation methods, and the sample name has been changed for somesamples.

*2: The standard at which intake of food and drinks is restricted for the purpose of preventing exposure due tooral intake(shown in Table 2.1).
*3: Nuclear Emergency Preparedness and Response Guidelines, Nuclear Regulation Authority (2018)(Reference 1)4

2.3 Contamination prevention measures
In emergency monitoring, many kinds of radionuclides are detected at high concentrations,contrary to normal time monitoring where they are not detected at all, or detected at extremely
low levels. Such high concentration samples can easily contaminate other samples,
measurement containers, laboratory equipment, or laboratory facilities, and have to behandled carefully at all times, not just in laboratories. Measures to prevent these potential
contaminations are classified into those that need to be prepared in advance (e.g., having
necessary laboratory equipment (tools) available and ready for use, designing the layout ofworkplaces for efficient work) and those that need to be carried out on site by the persons
engaged in the analysis or measurement (e.g., performing contamination inspection, covering
the surfaces, wearing rubber gloves and lab coat). One has to carefully examine the flow ofwork and establish the means and procedures necessary for realizing the contamination
prevention measures stated below.
It must be noted that, in emergency situations, radioactive iodine and radioactive cesium arelikely to be detected at high concentrations, and these radionuclides require special attention.
Radioactive iodineis highly volatile, and its chemical behavior is complicated. Radioactive
cesium has a longer half-life than radioactive iodine and its effects last longer. Therefore,
when pretreating and handling samples that may contain such substances, extra caution will
have to be taken in preventing contamination of laboratories and cross-contamination
between samples, as the affected areas and the scale of contamination can be unpredictable.
The major premise of any radioactivity measurement is that the items used in the process
are not contaminated; it is important to perform contamination inspection of the items before
work, after work, and when there was a possibility of contamination. Especially, instruments
and tools that are used repeatedly require contamination inspection and other necessary
measures to prevent cross- contamination. In addition, measures to reduce spreading ofcontamination to other work areas need to be taken, including allocating special shoes to eachlaboratory to be worn only in the laboratory, placinga sticky mat at the entrance of laboratories,
and regularly cleaning around the laboratories.*4 Further, it is important to prevent
contamination from outdoor air by, for example, sealing the gaps around the windows anddoors of laboratories using adhesive tape*5 and wrapping transportation containers with apolyethylene bag if a sample is to be transported between laboratories via an outdoor
environment.
Based on these understandings, the subsections below discuss the matters to be noted regarding
prevention of contamination and exposure to workers, cross-contamination between samples,and contamination of measurement containers, in the stages of sample acceptance, pretreatment,
and filling into measurement containers. As for high-concentration samples that call for special
attention, Information 2 provides the matters to be noted when handling them during sampling
and measurement.
2.3.1 Matters to be noted in the sample acceptance stage
The radioactivity concentrations in environmental samples are likely to change depending on
the state of contamination of the environmental around the sampling locations. Therefore,
when accepting samples, the analysis institution needs to check the sample information suchas the sampling location and ascertain the radiation level of the whole sample, including the*4: Yoshiyuki Kurita, Jun Saegusa, Satoshi Maeda, Survey and countermeasures on radiocesium inflow into a laboratorybuilding for radioactivity analysis, Japanese Journal of Radiation Safety Management, 15(2)(2016) (Reference 5)*5: Some gaps need to be left unsealed for fire safety reasons. Check whether they can be sealed or not beforesealing them.

5

bags, etc. containing the sample using survey meters*6. (Photographs 2.1 and 2.2)
Once accepted, samples are to be managed and stored with paying utmost attention toprevention of cross-contamination. The samples should be grouped by radiation level as partof cross-contamination prevention measures. For samples with high radiation levels, theanalysis institution needs to ensure that all necessary measures to minimize exposure toworkers are taken for the work environment, including storing them in a place where workers
do not usually enter. Also, in emergency monitoring, it is likely that a large number of samples
need to be handled in a short period of time, and the workers that handle the samples may bedifferent from the workers that handle the samples in normal time monitoring. Therefore, asample management method needs to be established in advance to prevent a mix-up of
samples.*7

Photograph 2.1
Measurement of samples using a survey
meter on acceptance (spinach)Photograph 2.2
Measurement of samples using a survey
meter on acceptance (closer view)

In addition, environmental samples with high radiation levels may serve as material for
determining the preparation method, as a small sample volume may be enough for analysis ormeasurement.
When performing these operations, workers have to wear disposable rubber gloves, lab coat,mask, etc., and assume that the bags, etc. containing the samples are contaminated.
(Photograph 2.3) If it is known in advance that the bags, etc. containing the samples arecontaminated, additional measures (e.g., wrapping double using polyethylene bags) will be
required to prevent cross-contamination of samples.

*6: Scintillation survey meters for gamma rays may be used for ascertaining the radiation level, and GM tube survey meters forcontamination inspection.
*7: An example sample management method is use of sample tags and labels. In such a case, using barcodeor two-

dimensional code would be helpful.

6

Photograph 2.3
Contamination prevention measures applied to worker(Disposable open back lab coat is worn)
Contamination prevention measures shall be taken for survey meters as well by, for example,
covering them with polyethylene bags before use and replacing the polyethylene bags asnecessary.
2.3.2 Matters to be noted in sample preparation
After receiving samples, the analysis institution needs to pay attention to potential
contamination due to the samples, outdoor air, or other causes for the laboratory rooms andaround the tables to prepare the samples for measurement. To that end, as for the laboratory
rooms and tables to be used, it is important to prevent contamination of their surfaces using
covering sheets*8 such as polyethylene filters and blue poly tarp. (Photographs 2.4 and 2.5)
In such a case, it is desirable to cover sample- handling facilities, etc. as much as possible,
including work spaces and their surroundings with covering sheet. Note that, depending on
the situation, covering sheets*9 may have to be doubled as it is possible that a covering sheet
breaks during use.
Further, some extra measures, such as replacing covering sheets for each sample, have to betaken to prevent radionuclides from being mixed in and samples from being crosscontaminated.
When handling samples, workers are required to wear disposable rubber gloves, lab coat,
surgical mask, etc., to prevent cross-contamination of samples, internal exposure of theworkers, and adhesion of radionuclides on the workers.
As for the covering sheets for laboratory tables, etc. and disposable rubber gloves worn byworkers, it is important to use new ones for each sample as part of contamination prevention
measures. If there has been possible contamination, they may have to be replaced, even in the
middle of preparation work.

*8: Include disposable sheets.
*9: There has been a case of using non-contaminated old newspaper when covering sheets ran short.

7

Photograph 2.4
Contamination prevention measures taken(covering using polyethylene filters)

Photograph 2.5
Contamination prevention measures taken(covering using blue poly tarps)

In the preparation of samples, tools such as kitchen knives, cutters, and trays used forchopping samples (Photograph 2.6) are to be carefully washed if they are reused. However,in some emergency cases, circumstances may not allow washing them thoroughly. Therefore,
use of disposable kitchen knives, cutters, paper plates, etc. is a valid means as a measure toprevent cross-contamination due to insufficient washing. In that case, extra attention needs tobe paid to the safety of preparation work as disposable kitchen knives and cutters are notcommonly used in sample preparations in normal times.
In addition, for liquid samples such as drinking water, contamination spreading prevention
measures (e.g., laying filter paper in a tray and working on it) are to be taken where necessary.

Photograph 2.6
Chopping a sample using a cutter on a paper plate(Chinese cabbage)
As for the tap water and pure water used for washing samples and tools, their contamination
status is to be checked before use. The method to check the contamination status shallconform to the method described in Chapter 6. If the tap water is found to contain radioactive
materials and likely to contaminate the samples, pure water is to be used instead.

8

2.3.3 Matters to be noted when filling a measurement container with a sample
The measurement containers adopted in this document are Marinelli beakers and small
plastic containers*10. A Marinelli beaker*11 is to be used with an inner bag specially designed
to fit its inner shape. As for small containers, they are not to be reused.
If special inner bag is not available, a polyethylene bag can be used instead. In such a case,the polyethylene bag shall be placed tightly against the inner wall of the Marinelli beaker so
as to not allow air to be present between the bag and beaker wall as much as possible.
When filling a measurement container with a sample (Photographs 2.7 and 2.8), the workers
need to take measures to prevent contamination of the outer surface of the measurement
container. An example method to achieve that is to divide workers into those that handle thesample (“hot” workers) and those that do not handle the sample (“cold” workers), and split thework so that the “hot” workers do not come into contact with the outer surface of themeasurement container.*12

Photograph 2.7
Filling a Marinelli beaker with asample(Chinese cabbage)

Photograph 2.8
Filling a small container with a sample(Chinese cabbage)

Once a sample is sealed up inside a measurement container, the outer surface of themeasurement container is to be decontaminated by wiping with a paper towel moistened withwater or ethanol*13 . After wiping the outer surface, the measurement container is to be placedin a polyethylene bag in a size suitable for the container as a measure to prevent contamination
arising from the measurement container itself, and then served for measurement.
2.4 Preparation method
In this document, the basic approach to emergency monitoring is to measure a sample as
sampled or as a raw sample, whenever possible, to ensure swift measurement and to prevent
spreading of contamination that may occur in emergency situations.
2.4.1 Preparation of food and drinks
Measurement results for food and drinks in emergencies are used for making a decision
related to OIL6 (see Table 2.1). Therefore, the preparation method was made consistent withthe method to test radioactive materials in food specified by the Ministry of Health, Labourand Welfare*14 and other relevant methods, with the understanding that it is to conform to the*10: A typical small container is U-8 container.
*11: Check the contamination status of Marinelli beaker before use.
*12: Recommended work splitting is a system in which hot workers place measurement containers on thelaboratory table andfill them with the sample, and cold workers transport the measurement containers.
*13: Acrylic container can be damaged by ethanol causing swell or crack.
*14: Manual for Measuring Radioactivity of Foods in Case of Emergency, Inspection and Safety Division, Department of Food9

general treatment method of food and drinks for consumption. In this document, such samples
are to be brushed to remove soil, etc. and washed with water*15 *16 to simulate preparation for
consumption. Note that the quantity (ratio) of radioactive materials removed from vegetables
by washing varies depending on the washing method. Readers are directed to Information 7
for the result of a study about washing vegetables.
2.4.2 Storage of samples
Sample storage methods are summarized from the viewpoints of “storage for a relatively shortperiod of time” and “long-term storage,” with clear descriptions on the concepts of storage
that take into account the time elapsed after the measurement of samples. In the case of storing
for a relatively short period of time, it is desirable that perishable samples are refrigerated orfrozen. Whether it is for a shortor long period of time, when storing samples, it is important torecord the sampling date, sampling location (including the information of latitude andlongitude and photographs whenever possible), information about the person(s) who collected
the sample, pretreatment, and the content and result of measurement. Be particularly mindfulthat some environmental samples collected for emergency monitoring cannot be disposed of
casually. Information 4 provides the matters to be noted for disposal of environmental samples.
2.4.2.1 Storage for relatively short period of time
It is possible that samples are stored for a relatively short period of time to perform remeasurement for various reasons (e.g., double checking of measurement results obtained by
gamma-ray spectrometry in emergencies). The expected period of storage is from several days
to several months.
In the case of storing samples for a relatively short period of time, as a preservative, formalin
was added in the past to prevent decomposition of samples such as cow’s milk, dairy products
and eggs. However, formalin is no longer used because of the health risk. Additionally, theprevious version of this document prescribed to add sodium chloride to precipitation andinland water samples to prevent adsorption on the container. In this version, based onliterature and results of the study shown in Explanation B, it was decided to add sodium
thiosulfate*17, in order to prevent adsorption of radioactive iodine on measurement
containers.*18 Note that, once sodium thiosulfate is added, the sample solution is to behandled solely as a sample for re-measuring radioactive iodine, and not to be transferred toanother storage container for measuring other radioactive materials.

Sanitation, Pharmaceutical and Medical Safety Bureau, Ministry of Health, Labour and Welfare (2002) (Reference 6)*15: Matter of Note for Inspection Based on the Manual for Measuring Radioactivity of Foods in Case of Emergency(Announcement), Inspection and Safety Division, Department of Food Sanitation, Pharmaceutical and Medical Safety
Bureau, Ministry of Health, Labour and Welfare (2011) (Reference 7)*16: As for tap water and pure water used for washing samples and tools, contamination status will be checkedbefore use. The

method to check the contamination status shall conform to the method described in Chapter 6.
*17: The oxidation state of reducible ions and compounds (e.g., iron) in a sample may change due to thereducing action of

sodium thiosulfate: pay attention to the change in the state of sample solution.
*18: To prevent adsorption or volatilization of radioactive materials in the sample container, it is desirable to carry out

preparation and measurement as quickly as possible.

102.4.2.2 Long-term storage
Some samples collected for emergency monitoring may be valuable. The section below
describes the methods to store such samples for a long period of time. The expected period ofstorage is in the order of years.
In the case of samples with little possibility of decomposing (e.g., soil), the samples are to be
stored as they are. For samples that may decompose, ashing treatment is to be applied. Whenperforming ashing, radioactive materials may be lost through vaporization etc. depending on
the nuclide or chemical structure. Attention needs to be paid to changes in the radioactivity
concentration in samples and contamination of other samples and equipment used. For water
samples, acid is to be added to the container for long-term storage for applying the storage
method for normal time monitoring. Information 3 describes the specific long-term storage
methods of samples. For details of ashing treatment and addition of acid to water samples, referto the Radioactivity Measurement Series No. 13 Pretreatment of Samples for Instrumental
Analysis using Germanium Detector, etc. (Reference 3) and Radioactivity Measurement SeriesNo. 16 Method for Sampling Environmental Materials (Reference 4).
2.5 Quantifiable levels
Tables 2.2 and 2.3 show the quantifiable levels of 131I, 134Cs and 137Cs that were obtainedby gamma-ray spectrometry using the method described in this document.
The detection limit in gamma-ray spectrometry varies depending on the concentration ofradioactivity in environmental samples. Therefore, the detection limit was calculated each by
the type of environmental sample and measuring time using spectra actually measured using
environmental samples (fallout, soil or air) collected after the Fukushima Daiichi Nuclear
Accident which were filled into a Marinelli beaker or small container. For the calculation, therelative efficiency of detectors was assumed to be about 30%, the general relative efficiency
of germanium semiconductor detectors currently available. Explanation A gives the detailsof the calculation method of quantifiable levels. The obtained limits of detection werecategorized by sample and designated as the quantifiable levels of 131I, 134Cs and 137Cs bymeasuring time.
The calculation method of detection limit was as prescribed in the Radioactivity
Measurement Series No. 7 Gamma-ray Spectrometry using Germanium Detector (Reference
8).
Information 1 describes the basic concept of implementation items and content ofemergency monitoring, including the relation between the quantifiable levels obtained here
and OIL6, the threshold of food and drink intake restrictions.
Note that the quantifiable levels shown in Tables 2.2 and 2.3 are guides and vary dependingon the type of radionuclides contained in the measurement container or their concentration.
Especially, 131I has a short half-life of 8 days and attention needs to be paid to the number ofdays elapsed from sampling to the commencement of measurement.
To determine the actual measurement conditions, preliminary measurement, etc. are to be
conducted. Additionally, consideration needs to be given to checking and changing
measurement conditions that sufficiently satisfy the reference values, as necessary. Analysis
institutions are required to take preparatory measures (e.g., collection and accumulation of
relevant data) in preparation of emergency situations.

11

Table 2.2 Chart between the measuring time and quantifiable level in emergency measurement (multi-nuclide detection) using a Marinelli beaker (2 L)

12Name of sample

Samplevolume(g)

10 min30 min1h

10 h

10 min30 min1h

10 h

10 min30 min1h

10 h

Fallout
Precipitation

2000 g

110

70

50

20

90

60

40

20

100

60

50

20

Bq/kg

Drinking water
Cow’s milk

2000 g

110

70

50

20

90

60

40

20

100

60

50

20

Bq/kg

Soil

3100 g

80

50

30

10

70

40

30

8

70

40

30

9

Bq/kg

Vegetables

1000 g

200

120

80

30

170

100

70

30

180

110

80

30

Bq/kg

Meats Eggs
Seafood1900 g

120

70

50

20

100

60

40

20

110

60

50

20

Bq/kg

131

137

I quantifiable level

134

Cs quantifiable level

The values are calculated with setting the relative efficiency of germanium
semiconductor detector to 38%. For vegetables, meats, eggs, and seafood, the values areradioactivity concentration per raw weight.

Cs quantifiable level
UnitTable 2.3 Chart between the measuring time and quantifiable level in emergency measurement (multi-nuclide detection) using asmall container (50 mmφ × 50 mm)
131

137

I quantifiable level

134

Cs quantifiable levelCs quantifiable level

Samplevolume(g or m3)

10 min30 min1h

10 h

10 min30 min1h

10 h

10 min30 min

1h

10 h

1 m3

6

4

3

0.8

6

3

2

0.7

8

5

3

1

10 m3

0.6

0.4

0.3

0.08

0.6

0.3

0.2

0.07

0.8

0.5

0.3

0.1

1000 m3

0.006

0.004

0.003

0.0008

0.006

0.003

0.002

0.0007

0.008

0.005

0.003

0.001

Fallout
Precipitation

89 g

350

200

150

50

280

170

120

40

310

180

130

40

Bq/kg

Drinking water
Cow’s milk

89 g

350

200

150

50

280

170

120

40

310

180

130

40

Bq/kg

Soil

140 g

240

140

100

30

190

110

80

30

200

120

90

30

Bq/kg

Vegetables

47 g

610

350

250

80

500

290

210

70

550

320

230

70

Bq/kg

Meats Eggs
Seafood

86 g

360

210

150

50

290

170

120

40

320

180

130

40

Bq/kg

Name ofsample

Air

Unit

Bq/m3

13

The values are calculated with setting the relative efficiency of germanium semiconductor detector to 31%. However, for the air, the values arecalculated with setting the relative efficiency to 27%.
For vegetables, meats, eggs, and seafood, the values are radioactivity concentration per raw weight.

2.6 Sample preparation
Samples prepared conforming to this document are measured by gamma-ray spectrometry
using germanium detectors. In gamma-ray spectrometry, obtained counts are divided by thepeak efficiency to derive the net gamma-ray emission rate. Geometrical conditions (e.g., shape,
height) and density of sample are some of the factors used to determine the peak efficiency, andthe state of the sample after preparation greatly affects the resultant quantitative values.
Therefore, factors that unnecessarily changequantitative values need to be eliminated as muchas possible.
Containers typically used in gamma-ray spectrometry are Marinelli beakers *19 (Figures 2.1
and 2.2) and small containers (Figure 2.3). For details, refer to the Radioactivity Measurement
Series No. 7 Gamma-ray Spectrometry using Germanium Detector (Reference 8). This
subsection discusses matters to be noted when preparing samples conforming to this documentin the case of Marinelli beakers and small containers.

2000 ml water level marking
700 ml water level marking

Figure 2.2 700 mL Marinelli beaker

2.5

61

Figure 2.1 2 L Marinelli beaker

50

Figure 2.3 Small container*19: Recently, 1 L Marinelli beakers have also become commercially available. However, the shape may bedifferent even if thecapacity is the same: pay attention when performing efficiency calibration.

14

2.6.1 In the case of using Marinelli beakers
Attention needs to be paid to samples that are solid and not fine, and therefore difficult to form
into acertain shape, such as soil, vegetables, grains, meats, dairy products, and seafood. Figure
2.4 illustrates (a) the shape of Marinelli beaker, (b) the state where a sample is sealed in an inner
bag for Marinelli beakers used in the method described in this document, and (c) the state whereair voids are generated between sample pieces.
In preparing a sample for measurement, it is important that the shape of the inner bag for
Marinelli beakers that contain the sample is the same as that of the inner wall of the Marinelli
beaker. Also, as shown in Figure 2.4 (b), the sample needs to be sealed in the inner bag for
Marinelli beakers without airvoids between the sample pieces.
When placing a special inner bag into a Marinelli beaker, it is advisable to apply talc, etc.*20
to the outer surface of the inner bag to facilitate the insertion. It is also a good idea to place 2
L of water into an inner bag placed in a Marinelli beaker using a graduated cylinder and markthe water level as an indicator of 2 L.

Air voids(a)(b) Acceptable(c) Not acceptable

Figure 2.4 Filling a Marinelli beaker with a sample
2.6.2 In the case of using small containers
Similarly to the case of using Marinelli beakers, when sealing a solid sample, care shall betaken so as to avoid air voids to generate. However, samples like vegetables and seaweeds may
not move easily and air voids may not disappear even when they are pressed firmly. Suchsamples may require some extra treatment such as chopping into small pieces. Additionally,
since the height of sample in a measurement container affects the peak efficiency, it isrecommended to apply pressure on the top surface of the sample using a laboratory spoon, jig,or rubber-gloved finger pad to level the surface and ensure homogeneous density throughout
the sample. For a particulate sample, attention needs to be paid as filling a container with thesample while hitting the container may cause small particles to move down and affect themeasurement results. Figure 2.5 shows the method to fill a small container with a sample.

*20: An extender pigment produced by crushing talc. Commercially available baby powders may be usedinstead.

15

Place the sample in asmall container.

Lightly press the top
surface of the sample.

Level both the top andbottom surfaces of thesample.

Figure 2.5 Filling a small container with a sample
It is advisable to mark small containers in advance at about 80% of the height of thecontainer,as a guideline for workers to fill when sealing a sample.

16

Chapter 3 Glossary
This chapter provides the definitions and explanations of terms used in this document andthose considered important in sample preparation.
Nuclear Emergency Preparedness and Response Guidelines (Reference 1)
Guidelines that stipulate specialized and technical matter to assist a nuclear operator, national
government, local government, etc. in making scientific and objective decisions when
formulating and implementing a plan pertaining to nuclear emergency measures.
Emergency monitoring (Reference 1)
Environmental radiation monitoring that is to be conducted in cases of abnormal release or
possible abnormal release of radioactive materials or radiation.
Normal time monitoring (Reference 9)
Ascertaining air radiation dose rate and concentration of radioactive materials in thesurroundings ofnuclear facilities in normal times to be prepared for emergency monitoring, as
well as for early detection of abnormality in nuclear facilities and evaluation of impact on local
residents and surroundings.
Atmosphere monitoring device (Reference 2)
A device to continuously measure concentration of radioactive materials (alpha-emitting
nuclides, beta-emitting nuclides, or both of them) in the atmosphere by suctioning airborne
particles along with the air using a pump and counting radiation from particles collected on
filters using a radiation detector.
Environmental sample
Sample used for measuring environmental radioactivity. Typical environmental samples
include airborne particles, fallout, inland water, soil, polished rice, vegetable, tea, cow’s milk,commonly consumed food, seawater, sea sediment, saltwater fish, freshwater fish, shellfish, andseaweeds.
Iodine sampler (Reference 10)
A device to collect iodine using a filtration material for collecting iodine for the purpose ofderiving radioactivity concentration in the air arising from airborne radioactive iodine.
Monitoring station (References 11 and 12)
Fixed outdoor facility to continuously monitor air absorbed dose rates, air kerma rates orambient dose equivalent rates of environmental gamma-rays, or neutron fluence rates.
Survey meter (Reference 13)
Portable radiation measurement equipment. Aims to measure ambient radiation dose rate or
surface contamination. Available in an ionization chamber type, GM tube type, NaI scintillation
type, and plastic scintillation type, each of which have unique characteristics. It is required to
select the suitable equipment according to the environment to be used17

Germanium semiconductor detector (Reference 13)
A kind of semiconductor radiation detector, in which a single crystal of germanium is used asa detection element. It utilizes the nature of a semiconductor generating ionized current pulses
when it is subjected to radiation while voltage is applied to it in the anti-rectification direction.
This enables detecting gamma-rays and X-rays with high sensitivity and energy resolution.
Detection limit (References 8 and 14)
The lowest concentration (quantity) of analyte nuclide that can be detected for the given
sample and measurement conditions (e.g., measurement equipment, measuring time). Amongthe various conceptsto calculate the detection limit proposed, the Cooper’s method was adopted
in this document.
Quantifiable level
A level at which quantification is deemed possible for the same sample type, sample volume
and analysis conditions (e.g., measuring time), specified based on data on detection limit. In
this document, the detection limit was calculated for each type of environmental sample andmeasuring time using spectra that were actually measured using environmental samples (fallout,soil or air) collected after the Fukushima Daiichi Nuclear Accident which were filled into a
Marinelli beaker or small container, and the result was specified as the quantifiable level. Notethat this is different in concept from the limit of quantification commonly used in the field ofanalytical chemistry (ten times the standard deviation of background measurement values).
Peak efficiency (Reference 8)
A collective term for relative peak efficiency, reference peak efficiency, and absolute peakefficiency that includes correction factors such as self-absorption.
Constant mass (Reference 14)
A state in which the difference in the measured mass of a substance before and after a cycleof treatment has become at or below a specified value when the substance is repeatedly
subjected to a certain set of operations (e.g., heating, allowing to cool, and weighing) under thesame conditions.
Dead time (Reference 15)
The time spent to convert the injected gamma-rays into signals. The detector cannot
process subsequent injection of gamma-rays during this interval (being dead).
Thus, dead time is obtained by subtracting the live time from real time (i.e., true time).

18

Reference
1 「原子力災害対策指針」原子力規制委員会（2018）
2 「緊急時モニタリングについて（原子力災害対策指針補足参考資料）」
原子力規制庁監視情報課（2017）
8 放射能測定法シリーズ No.7「ゲルマニウム半導体検出器によるガンマ線
スペクトロメトリー」
9 「平常時モニタリングについて（原子力災害対策指針補足参考資料）」
原子力規制庁監視情報課（2018）
10 JIS Z4336：2010 放射性ヨウ素サンプラ
11 放射能測定法シリーズ No.17「連続モニタによる環境 γ 線測定法」
12 JIS Z4325：2008 環 境 γ 線連続モニタ
13 JIS K0216：2014 分析化学用語（環境部門）
14 JIS K0211：2013 分析化学用語（基礎部門）
15 放射能測定法シリーズ No.29「緊急時におけるゲルマニウム半導体検出器による
γ線スペクトル解析法」

19

Chapter 4 AtmosphereThis chapter describes how to prepare and store glass fiber filters, long filters and active carbon
cartridges as samples for measurement of radioactive materials, especially radioactive iodine*1,
in the atmosphere. Measurement containers used are Marinelli beakers or small containers.
4.1 Equipment, tools, etc.to be needed･ Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface)･ Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)･ Inner bags for Marinelli beaker･ Polyethylene bags for sealing measurement containers･ Plastic tape･ Paper towels･ Ethanol･ Pure water*2･ Lab coat (preferably disposable type)･ Disposable polyethylene or rubber gloves･ Arm covers･ Disposable masks･ Large filter (roughly 60 cm × 60 cm)･ Plastic sheet (plastic bag may be used instead)･ Ruler･ Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer)*3 (With the operation panel, top
plate, etc. covered by wrap films to prevent contamination of the surface)
4.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves andlab coats to prevent exposure and contamination.
(b) Check the sampling location, sampling period, sampling conditions, etc. and assign
identification numbers to the samples.
(c) Place a survey meter as close as possible to the samples and measure radiation levels tofind samples with potentially high radioactivity. Assume the dead time when measured
using a germanium semiconductor detector based on the sample volume and radiationlevel, and adjust the sample volume so that the dead time can be about 10% or less asmuch as possible, and select a measurement container sized for the sample volume.*4
Select small containers for measurement if the radiation levels from the samples are high.
*1: Radioactive iodine exists in the atmosphere in particulate and gaseous forms. Particulate iodine consistsof iodine salts, etc.

contained in airborne particles, and gaseous iodine inorganic iodine (e.g., I2) and organic iodine (e.g., methyl iodide).
Particulate iodine is collected by glass fiber filters, and gaseousiodine by active carbon cartridges.
*2:Confirm in advance the pure water is free of radioactive materials.
*3: Use balances that are properly controlled (e.g., periodically inspected and calibrated).
*4: Forthe relationship between dose rates at the surface of sample measured using a survey meter

andradioactivity concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for
Measurement of Radioactive Cesium in Food in Emergencies (2nd Edition) issued by the Japan Radioisotope
Association in 2011 (Reference 16), which provides data for each model.

20(d) Ascertain the contamination situation of the sample from the result of measurement using

the survey meter, and take measures accordingly. Measures include storing high radiationlevel samples that are separated from low radiation level samples, and controlling thetime for workers to handle the samples to reduce the workers exposure. The samples
which are expected to have high radioactivity should be treated separately to prevent
unnecessary exposure and cross contamination.
4.3 Sample preparation method
4.3.1 Matters to be noted in sample preparation(a) To prevent cross-contamination, determine in advance the order of samples to be prepared,
based on the results of survey meter measurements conducted when the samples werecarried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Place a plastic sheet on a covered workbench, further place large filters on top of it, andwork on them separately for each sample.*5(e) To prevent spreading of contamination from the sample, it is desirable to separate hot
work through direct contact with the sample from cold work through indirect contact
with the sample, and separate workers and workbenches between hot work and cold work
as much as possible.
4.3.2 Filling measurement container with sample(1) In the case of using small containers(a) Write or attach the necessary data (e.g., sample identification number) to a small
container, and measure and record the tare weight of the small container.
(b) While paying attention to the homogeneity of the sample, place pretreated (e.g., folded)
filters*6 into the small container prepared in (1). In so doing, try not to make gaps between
samples and the container wall. (Photograph 4.1) For small filters and punched filters,
place them with the airborne particle-attached side facing the bottom.*7 (Photograph 4.2)(c) Place a cap on the small container, measure the height of the sample and record it.
(d) Thoroughly wipe the outer surface of the container with a paper towel moistened with purewater,ethanol, etc.
(e) Measure the weight of the small container, derive the weight of the sample by subtracting
the tare weight measured above, and record it.
(f) To prevent contamination of measurement equipment, cover the small container with apolyethylene bag, remove air, tie the bag opening to seal it (ensure no creases at thebottom of the container), and present it as a sample for measurement. (Photograph 4.3)

*5: Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.
*6: Example methods of pretreatment are provided in 4.5.
*7

: If multiple sheets of filters are provided as a sample, stack them.

21

Photograph 4.1
Small container with a sample
placed in it (glass fiber filter)

Photograph 4.2
Airborne particle-attached side
facing the bottom (glass fiber filter)

Photograph 4.3
The small container covered in a polyethylene bag(glass fiber filter)(2) In the case of using Marinelli beakers*8(a) Place an inner bag in a Marinelli beaker without any gaps. (Use disposable bags toprevent contamination of the wall of the measurement container.)(b) Write or attach the necessary data (e.g., sample identification number) to the Marinelli
beaker, and measure and record the tare weight of the Marinelli beaker, lid and inner bag.
(c) While paying attention to the homogeneity of the sample, place pretreated (e.g., folded,
cut out) filters*9 into the Marinelli beaker up to the marked line. In so doing, try not tomake gaps between samples and from the container wall as much as possible.
(Photograph 4.4) After placing the sample, measure the weight of the Marinelli beakerand lid along with the sample, derive the weight of the sample by subtracting the tareweight measured above, and record it.
(d) Seal the inner bag of Marinelli beaker using plastic tape.*10 (Photograph 4.5)(e) Place the lid on the Marinelli beaker, and seal with plastic tape.
(Photographs 4.6 and 4.7)
*8: This method is intended for swiftly measuring a large quantity of filters. If a person desires to measure dust collected

sections only, the method to place a sample in a small container is available as shown in 4.3.2 (1).
*9: Example methods of pretreatment are provided in 4.5.
*10

: A rubber band, cable tie, etc. may be used instead.

22

(f) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel moistenedwith pure water, ethanol, etc.
(g) To prevent contamination of measurement equipment, place the Marinelli beaker in apolyethylene bag, remove air, tie the bag opening to seal it, and present it as a sample formeasurement. (Photograph 4.8)

Photograph 4.4
Marinelli beaker filled with asample(long filter)

Photograph 4.5
Sealing the inner back with plastic tape(long filter)

Photograph 4.6
Fixing the lid with plastic tape(long filter)

Photograph 4.7
Fixing the lid with plastic tape(long filter)

Photograph 4.8
The Marinelli beaker covered in apolyethylene bag(long filter)23

4.3.3 Preparation of active carbon cartridge*11
In an emergency, to prevent contamination from the collecting material, it is preferable tomeasure the active carbon cartridge as it is*12, without taking the collecting material out of theactive carbon cartridge. However, if a standard radiation source that fits the form of the active
carbon cartridge is not available, the collecting material is to be taken out by the following
method and presented as a sample for measurement.
(1) In the case of using small containers(a) Write or attach the necessary data (e.g., sample identification number) to a small
container, and measure and record the tare weight of the small container.
(b) Take the collecting material out of the active carbon cartridge and place in the small
container. (Photograph 4.9) In so doing, pay extra attention to the collecting material
scattering around dueto static electricity, etc.*13(c) Place a cap on the small container, measure the height of the sample and record it.
(Photograph 4.10)(d) Thoroughly wipe the outer surface of the container with a paper towel moistened with purewater,ethanol, etc.
(e) Measure the weight of the small container, derive the weight of the sample by subtracting
the tare weight measured above, and record it.
(f) To prevent contamination of measurement equipment, place the small container in apolyethylene bag, remove air, tie the bag opening to seal it (ensure no creases at thebottom of the container), and present it as a sample for measurement.

Photograph 4.9
Taking active carbon out

Photograph 4.10
Small container with a sample
placed in it (active carbon)

4.4 Storage of samples
4.4.1 Storage for a relatively short period of time(a) Samples prepared using small containers: place sample-containing inner bags into apolyethylenebag or a container.
(b) Samples prepared using Marinelli beakers: place sample-containing measurement
containers into a polyethylene bag or a container.
(c) Cartridges that were measured without taking collecting material out: place them into a*11: The pretreatment method for active carbon filters is the same as that for glass fiber filters.

*12: In some cases, an active carbon cartridge is measured with filters placed next to it. In such a case, ensure the suctioned side
faces the detector.

*13: To prevent spreading of contamination or scattering of sample, it is advisable to apply a static eliminatoror aluminum foil.

24

polyethylene bag or a container.
4.4.2 Long-term storage(a) Samples prepared using small containers: place sample-containing inner bags into apolyethylenebag or a container.
(b) Samples prepared using Marinelli beakers: place sample-containing measurement
containers into a polyethylene bag or a container.
(c) Cartridges that were measured without taking collecting material out: place them into apolyethylene bag or a container.
(d) Samples may be ashed by the methods provided in the Radioactivity Measurement SeriesNo. 13 Pretreatment of Samples for Instrumental Analysis using Germanium Detector,
etc. (Reference 3) and Radioactivity Measurement Series No. 16 Method for Sampling
Environmental Materials (Reference 4). In such a case, contamination of other samples
needs to be prevented by, for example, washing and cleaning instruments, tools andequipment after use. Ashed samples are to be stored in a low-humidity environment (e.g.,
inside a desiccator) or by taking measures to prevent contact with air as much as possible.
4.5 Pretreatment methods for long (continuous) filters and large filters and their characteristics
Long (continuous) filters and large filters used in atmosphere monitoring devices are treatedby various pretreatment methods. In emergency monitoring, in principle, a small amount offilter is to be measured using a small container, and a filter that is too large to fit into a small
container is to be measured using a Marinelli beaker. The pretreatment methods shown below
have their own unique characteristics. The most adequate method that suits the purpose needs
to be selected.*14(1) Folding*15

This is a method to prepare a sample by folding a large filter and placing it in a measurement
container.
A filter is folded with the airborne particle-attached side facing inside so that the filter fits
into a measurement container.*16 *17
Advantages: Specific instruments or tools are not required, and therefore the risk ofsample cross- contamination and environmental contamination isrelatively low.
Disadvantages: The filling rate into measurement container tends to have large
individual differences. Airborne particles may attach to a section of filter
which was free from airborne particles.
(2) Cutting out or punching out*15

This is a method to prepare a sample by cutting out an airborne particle-attached section ofa long (continuous) filter or large filter using a pair of scissors or punching such a section
out using a special instrument or tool and placing it in a measurement container.
Cutting out or punching out a filter into the diameter of measurement container makes it easy

*14: Note that efficiency calibration according to the state of sample needs to be performed.
*15: Refer to the Radioactivity Measurement Series No. 16 Method for Sampling Environmental Materials(Reference 4).
*16: In cases of large filters, they may be cut into an appropriate size before folding.
*17: Scattering of sample may be prevented, where necessary, by covering with a polyethylene bag or laminatefilm.

25

to place the filter into the measurement container.*18 When placing into a measurement
container, the airborne particle-attached side shall be facing downward.*19
Advantages: The filling rate into measurement container (small container) is high, andthe filling rate tends to have little individual differences.
Disadvantages: Attention needs to be paid to prevention of cross-contamination via
instruments andtools used for cutting or punching.
(3) Ashing*20

This is a method to folding a long (continuous) filter or large filter with the airborne particleattached side facing inside (or in a wound-up state*21), place in a porcelain plate, ash using
an electric furnace, etc., and measure.*22
Advantages: This method enables preparing a sample from a large quantity of filters thatcannot be otherwise placed in a measurement container. The homogeneityof sample is high compared as other methods.
Disadvantages: Contamination of other samples needs to be prevented by, for example,
washing and cleaning instruments, tools and equipment after use. Not
applicable to volatile nuclides. An abnormal rise in the temperature of theelectric furnace above the set value may cause volatilization ofradionuclides to which ashing is supposed to be applicable. Pretreatment
takes time, making this method less swift compared as other methods.

*18: The area of the suctioned section and cut out (punched out) section will be required for calculatingradioactivity

concentration.
*19: If multiple sheets of filters are provided as a sample, stack them.
*20: Ashing cannot be applied to some filters, such as filter roll for iCAM (Canberra).
*21: The core is to be removed in advance.
*22: Refer to the Radioactivity Measurement Series No. 13 Pretreatment of Samples for Instrumental Analysis using

Germanium Detector, etc. (Reference 3).

26

Chapter 5 Fallout and precipitation
This chapter describes how to prepare samples of fallout collected by a large reservoir, etc.
and preparation collected by a rainwater sampler, etc. Measurement containers used are
Marinelli beakersor small containers.
5.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)
 Inner bags for Marinelli beaker Polyethylene bags for sealing measurement containers
 Piston pipette Plastic tape
 Thread seal tape Paper towels
 Ethanol Sodium thiosulfate
 Pure water*1
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers
 Disposable masks
 Large filter (roughly 60 cm × 60 cm)
 Plastic sheet (plastic bag may be used instead) Tray Ruler Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer)*2 (With the operation panel, top
plate, etc. covered by wrap films, etc. to prevent contamination of the surface)
5.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves
and labcoats to prevent exposure and contamination.
(b) Check the sampling location, sampling period, sampling amount, sampling conditions,etc. and assign identification numbers to the samples.
(c) Place a survey meter as close as possible to the samples and measure radioactivity
levels tofind samples with potentially high radioactivity. The required amount of sample
is 100 g or more (the volume will be 100 mL or more) for small containers and 2 kg or
more (the volume will be 2 L or more) for Marinelli beakers. Assume the dead time whenmeasured using a germanium semiconductor detector based on the sample volume andradiation level, and adjust the sample volume so that the dead time can be about 10% orless as much as possible, and select a measurement container sized for the sample*1: Confirm in advance the pure water is free of radioactive materials.
*2: Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.

27

volume.*3 Select small containers for measurement if the radiation levels from thesamples are high.
(d) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take measures accordingly. Measures include storing high radiationlevel samples that are separated from low radiation level samples, and controlling thetime for workers to handle the samples to reduce exposure. The samples which are
expected to have high radioactivity should be treated separately to prevent unnecessary
exposure and cross contamination.
(e) To prevent adsorption or volatilization of radioactive materials in the sample container,
it is desirable to carry out preparation and measurement as quickly as possible.
5.3 Sample preparation method*4
5.3.1 Matters to be noted in sample(a) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Place a plastic sheet on a covered workbench, further place large filters on top of it, andwork on them separately for each sample. Lay filter paper in a tray and work on asnecessary.*5(e) To prevent spreading of contamination from the sample, it is desirable to separate hot
work through direct contact with the sample from cold work through indirect contact,and separate workers and workbenches fbetween hot work and cold work as much as
possible.
5.3.2 Filling measurement container with sample(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any gaps. (Usedisposablebags to prevent contamination of the wall of the measurement container.)(b) Write and attach the necessary data (e.g., sample identification number) to the Marinelli
beaker, then measure and record the tare weight of the Marinelli beaker, lid and innerbag.
(c) Mix the sample well, and place it in the Marinelli beaker prepared in (2) up to the marked
line. Use a piston pipette to finely adjust to the marked line.
(d) To prevent adhesion of nuclides to the inner wall of container, add 80-100 mg of sodium
thiosulfate per 1 L of sample.*6*3: For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which provides
data for each model.
*4: See Chapter 6 for the photographs of preparation.
*5: Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.
*6: Manual for Measuring Radioactivity of Tap Water, etc., Ministry of Health, Labour and Welfare (2011) (Reference 17)28

(e) Measure the weight of the Marinelli beaker and lid along with the sample, derive theweight ofthe sample by subtracting the tare weight measured above, and record it.
(f) Seal the inner bag of Marinelli beaker using plastic tape.*7(g) Place the lid on the Marinelli beaker, and seal with plastic tape.
(h) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel moistenedwith pure water, ethanol, etc.
(i) To prevent contamination of measurement equipment, place the Marinelli beaker in apolyethylene bag, remove air, tie the bag opening to seal it, and present it as a sample formeasurement.
(j) Derive the portioning rate from the sampling amount and sample volume using thefollowing formula:Portioning rate (%) =Sample volume (g)Sampling amount (g)× 100(2) In the case of using small containers(a) Mix the sample solution well in advance to make contained foreign matter (e.g., dust)
uniform.
(b) To prevent leakage, wrap thread seal tape around the threaded part of small container.
(c) Write or attach the necessary data (e.g., sample identification number) to a small
container, and measure and record the tare weight of the small container.
(d) Place approximately 80 g of sample into the small container prepared in (3). Use apiston pipette to finely adjust the volume. Place the entire sample if the sample volume
is small.
(e) To prevent adhesion of nuclides to the inner wall of container, add 80-100 mg of
sodium thiosulfate per 1 L of sample (6.4-8.0 mg per 80 g of sample).*8(f) Place a cap on the small container, measure the height of the sample and record it.
(g) Thoroughly wipe the outer surface of the container with a paper towel moistened withpure water, ethanol, etc.
(h) Measure the weight of the small container, derive the weight of the sample by subtracting
the tare weight measured above, and record it.
(i) To prevent contamination of measurement equipment, place the small container in apolyethylene bag, remove air, tie the bag opening to seal it (ensure no creases at thebottom of the container), and present it as a sample for measurement.
(j) Derive the portioning rate from the sampling amount and sample volume using thefollowing formula:Portioning rate (%) =Sample volume (g) × 100
Sampling amount (g)5.4 Storage of samples
5.4.1 Storage for a relatively short period of time(a) Samples prepared using Marinelli beakers: place sample-containing inner bags into
apolyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing measurement
containers into a polyethylene bag or a container.
*7: A rubber band, cable tie, etc. may be used instead.
*8: Manual for Measuring Radioactivity of Tap Water, etc., Ministry of Health, Labour and Welfare (2011)(Reference 17)29(c) In either case, store samples in a refrigerator or cool dark place to prevent
decomposition.
5.4.2 Long-term storage(a) To prevent adhesion of nuclides to the inner wall of container during long-term storage,
if iodine is not included in the nuclides to be measured, add about 1 mL of hydrochloric
acid (~12mol/L) or nitric acid (~13 mol/L) per 1 L of sample.*9 *10(b) Store samples in a refrigerator or cool dark place to prevent decomposition.

*9:

According to the Radioactivity Measurement Series No. 13 Pretreatment of Samples for Instrumental Analysis using
Germanium Detector, etc. (Reference 3) and Radioactivity Measurement Series No. 16 Method for Sampling Environmental
Materials (Reference 4).

*10: Do not add acid if iodine is included in the nuclides to be measured. (Iodine becomes volatile when acid is added.)30

Chapter 6 Drinking water and inland water
Different methods are applied to emergency monitoring of drinking water (e.g., tap water, well
water, rainwater) and inland water (e.g., river water, lake water), depending on the purpose ofmonitoring and the phase of nuclear emergency.*1 This Chapter describes how to prepare andstore drinking water and inland water samples without separating dissolved matter andsuspended matter. Measurement containers used are Marinelli beakers or small containers. If
separation of dissolved matter and suspended matter is required, refer to Information 5.
6.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)
 Inner bags for Marinelli beaker Polyethylene bags for sealing measurement containers
 Piston pipette Plastic tape
 Thread seal tape Paper towels
 Ethanol Sodium thiosulfate
 Pure water *2
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers
 Disposable masks
 Large filter (roughly 60 cm)
 Plastic sheet (plastic bag may be used instead) Tray Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer) *3(With the operation panel, top
plate, etc. covered by wrap films, etc. to prevent contamination of the surface)*1: In an emergency situation, usually separation is not performed in order to prioritize swift measurement and ease of operation.

However, there has been a case of separating them to study the difference in the behavior of dissolved matter and suspended
matter. Takahiro Nakanishi, Kazuyuki Sakuma, Trend of 137Cs concentration in river water in the medium term and future
following the Fukushima nuclear accident, Chemosphere, 295 (2019) (Reference 18)*2: Confirm in advance the pure water is free of radioactive materials.
*3: Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.

31

6.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves andlab coats to prevent exposure and contamination.
(b) Check the sampling location, sampling date, sampling conditions, etc. and assign
identification numbers to the samples.
(c) Place a survey meter as close as possible to the samples and measure radiation levels tofind samples with potentially high radioactivity. Assume the dead time when measured
using a germanium semiconductor detector based on the sample volume and radiationlevel, and adjust the sample volume so that the dead time can be about 10% or less to theextent as much as possible, and select a measurement container sized for the sample
volume.*4 Select small containers for measurement if the radiation levels from thesamples are high.
(d) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take proper measures accordingly. Measures include storing highradiation level samples that are separated from low radiation level samples, andcontrolling the time for workers to handle the samples to reduce exposure. The samples
which are expected to have high radioactivity should be treated separately to prevent
unnecessary exposure and cross contamination.
(e) To prevent adsorption or volatilization of radioactive materials in the sample container,
it is desirable to carry out preparation and measurement as quickly as possible.
6.3 Sample preparation method
6.3.1 Matter to be noted in sample preparation(1) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(2) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(3) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(4) Place a plastic sheet on a covered workbench, further place large filters on top of it, andwork on them separately for each sample. Lay filter paper in a tray and work on asnecessary.*5(5) To prevent spreading of contamination from the sample, it is desirable to separate hot
work through direct contact with the sample from cold work through indirect contact
with the sample, and separate workers and workbenches between hot work and cold work
as far as possible.

*4: For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which
provides data for each model.
*5: Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.

32

6.3.2 Filling measurement container with sample(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any gaps. (Usedisposablebags to prevent contamination of the wall of the measurement container.)(b) Write or attach the necessary data (e.g., sample identification number) to the Marinelli
beaker, and measure and record the tare weight of the Marinelli beaker, lid and inner bag.
(c) Mix the sample well, and place it in the Marinelli beaker prepared in (2) up to the marked
line. (Photograph 6.1) Use a piston pipette to finely adjust to the marked line.
(d) To prevent adhesion of nuclides to the inner wall of container, add 80-100 mg of
sodium thiosulfate per 1 L of sample.*6(e) Measure the weight of the Marinelli beaker and lid along with the sample, derive theweight ofthe sample by subtracting the tare weight measured above, and record it.
(f) Seal the inner bag of Marinelli beaker using plastic tape.*7 (Photograph 6.2)(g) Place the lid on the Marinelli beaker, and seal with plastic tape. (Photographs 6.3 and
6.4)(h) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel moistenedwith pure water, ethanol, etc.
(i) To prevent contamination of measurement equipment, place the Marinelli beaker in apolyethylene bag, remove air, tie the bag opening to seal it, and present it as a sample formeasurement. (Photograph 6.5)

Photograph 6.2
Sealing the inner back with plastictape(drinking water)

Photograph 6.1
Marinelli beaker filled with asample(drinking water)*6: Manual for Measuring Radioactivity of Tap Water, etc., Ministry of Health, Labour and Welfare (2011) (Reference 17)*7: A rubber band, cable tie, etc. may be used instead.

33

Photograph 6.3
Fixing the lid with plastic tape(drinking water)

Photograph 6.4
Fixing the lid with plastictape(drinking water)

Photograph 6.5
The Marinelli beaker covered in apolyethylene bag (drinking water)(2) In the case of using small containers(a) To prevent leakage, wrap seal tape around the threaded part of small container.
(Photograph 6.6)(b) Write or attach the necessary data (e.g., sample identification number) to a small
container, and measure and record the tare weight of the small container.
(c) Mix the sample well, and place approximately 80 g of sample into the small container
prepared in (2). (Photograph 6.7) Use a piston pipette to finely adjust the volume.
(d) To prevent adhesion of nuclides to the inner wall of container, add 80-100 mg of
sodium thiosulfate per 1 L of sample (6.4-8.0 mg per 80 g of sample).*8(e) Place a cap on the small container, measure the height of the sample and record it.
(f) Thoroughly wipe the outer surface of the container with a paper towel moistened withpure water, ethanol, etc.
(g) Measure the weight of the small container, derive the weight of the sample by subtracting
the tare weight measured above, and record it.

*8

Manual for Measuring Radioactivity of Tap Water, etc., Ministry of Health, Labour and Welfare (2011) (Reference 17)34

(h) To prevent contamination of measurement equipment, place the small container in apolyethylene bag, remove air, tie the bag opening to seal it (ensure no creases at thebottom of the container), and present it as a sample for measurement. (Photograph 6.8)

Photograph 6.6
Wrapping thread seal tape around thethreaded part (drinking water)

Photograph 6.7
Small container containing asample(drinking water)

Photograph 6.8
The small container covered in apolyethylene bag (drinking water)
6.4 Storage of samples
6.4.1 Storage for a relatively short period of time(a) Samples prepared using Marinelli beakers: place sample-containing inner bags into apolyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing measurement
containersinto a polyethylene bag or a container.
(c) In either case, store samples in a refrigerator or cool dark place to prevent decomposition.
6.4.2 Long-term storage(a) To prevent adhesion of nuclides to the inner wall of container during long-term storage,
if iodine is not included in the nuclides to be measured, add about 1 mL of hydrochloric
acid (~12 mol/L) or nitric acid (~13 mol/L) per 1 L of sample. *9 *10(b) Store samples in a refrigerator or cool dark place to prevent decomposition.
*9 According to the Radioactivity Measurement Series No. 13 Pretreatment of Samples for Instrumental Analysis using

Germanium Detector, etc. (Reference 3) and Radioactivity Measurement Series No. 16Method for Sampling Environmental
Materials (Reference 4).
*10

Do not add acid if iodine is included in the nuclides to be measured. (Iodine becomes volatile when acid is added.)35

Chapter 7 SeawaterThis chapter describes how to prepare and store seawater as samples for measurement. Obvious
foreign matters (e.g., seaweeds) are to be removed by a sedimentation method, but further
treatment such as filtration is not to be applied. Measurement containers used are Marinelli
beakers or small containers.
7.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)
 Inner bags for Marinelli beaker Polyethylene bags for sealing measurement containers
 Piston pipette Plastic tape
 Thread seal tape Paper towels
 Ethanol Pure water *11
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers
 Disposable masks
 Large filter (roughly 60 cm × 60 cm)
 Plastic sheet (plastic bag may be used instead) Tray, etc.
 Ruler Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer)*2 (With the operation panel, top
plate, etc. covered by wrap films, etc. to prevent contamination of the surface)
7.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves andlab coats to prevent exposure and contamination.
(b) Check the sampling location, sampling period, sampling amount, sampling conditions,etc. and assign identification numbers to the samples.
(c) Place a survey meter as close as possible to the samples and measure radiation levels tofind samples with potentially high radioactivity. Assume the dead time when measured
using a germanium semiconductor detector based on the sample volume and radiationlevel, and adjust the sample volume so that the dead time can be about 10% or lower as
much as possible. and select a measurement container sized for the sample volume.*3
Select small containers for measurement if the radiation levels from the samples are high.
*1: Confirm in advance the pure water is free of radioactive materials.
*2: Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.
*3: For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which
provides data for each model.

36(d) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take measures accordingly. Measures include storing high radiationlevel samples that are separated from low radiation level samples, and controlling thetime for workers to handle the samples to reduce exposure. The samples which are
expected to have high radioactivity should be treated separately to prevent unnecessary
exposure and cross contamination.
7.3 Sample preparation method*4
7.3.1 Matters to be noted in sample preparation(a) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Place a plastic sheet on a covered workbench, further place large filters on top of it, andwork on them separately for each sample. Lay filter paper in a tray and work on it asnecessary.*5(e) To prevent spreading of contamination from the sample, it is desirable to separate hot
work through direct contact with the sample from cold work through indirect contact,and it is desirable to separate workers and workbenches between hot work and cold work.
7.3.2 Filling measurement container with sample(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any gaps. (Usedisposablebags to prevent contamination of the wall of the measurement container.)(b) Write or attach the necessary data (e.g., sample identification number) to the Marinelli
beaker, and measure and record the tare weight of the Marinelli beaker, lid and innerbag.
(c) Mix the sample well, and place it in the Marinelli beaker prepared in (2) up to themarked line. Use a piston pipette to finely adjust to the marked line.
(d) Measure the weight of the Marinelli beaker and lid along with the sample, derive theweight of the sample by subtracting the tare weight measured above, and record it.
(e) Seal the inner bag of Marinelli beaker using plastic tape.*6(f) Place the lid on the Marinelli beaker, and seal with plastic tape.
(g) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel moistenedwith pure water, ethanol, etc.
(h) To prevent contamination of measurement equipment, place the Marinelli beaker in apolyethylene bag, remove air, tie the bag opening to seal it, and present it as a sample formeasurement.

*4: See Chapter 6 for the photographs of preparation.
*5: Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.
*6: A rubber band, cable tie, etc. may be used instead.

37

(2) In the case of using small containers(a) To prevent leakage, wrap seal tape around the threaded part of small container.
(b) Write or attach the necessary data (e.g., sample identification number) to a small
container, and measure and record the tare weight of the small container.
(c) Mix the sample well, and place approximately 80 g of sample into the small container
prepared in (2). Use a piston pipette to finely adjust the volume.
(d) Place a cap on the small container, measure the height of the sample and record it.
(e) Thoroughly wipe the outer surface of the container with a paper towel moistened withpure water, ethanol, etc.
(f) Measure the weight of the small container, derive the weight of the sample by subtracting
the tare weight measured above, and record it.
(g) To prevent contamination of measurement equipment, place the small container in apolyethylene bag, remove air, tie the bag opening to seal it (ensure no creases at thebottom of the container), and present it as a sample for measurement.
7.4 Storage of samples
7.4.1 Storage for a relatively short period of time(a) Samples prepared using Marinelli beakers: place sample-containing innerbags into apolyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing
measurement containersinto a polyethylene bag or a container.
(c) In either case, store samples in a refrigerator or cool dark place to prevent decomposition.
7.4.2 Long-term storage(a) Samples prepared using Marinelli beakers: place sample-containing inner bags
into a polyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing measurement
containers into a polyethylene bag or a container.
(c) In either case, samples may be transferred into a storage container as necessary.*7
To prevent adhesion of nuclides to the inner wall, if iodine is not included in the
nuclides to be measured, add about 1 mL of hydrochloric acid (~12 mol/L) or
nitric acid (~13 mol/L) per 1 L of sample.*8 *9(d) Store samples in a refrigerator or cool dark place to prevent decomposition.

*7: When a sample is to be transferred, pay attention to the homogeneity of the sample and transfer the entire sample if possible.
*8: According to the Radioactivity Measurement Series No. 13 Pretreatment of Samples for Instrumental Analysis using

Germanium Detector, etc. (Reference 3) and Radioactivity Measurement Series No. 16 Method for Sampling
Environmental Materials (Reference 4).
*9: Do not add acid if iodine is included in the nuclides to be measured. (Iodine becomes volatile when acid is added.)38

Chapter 8 Soil
Different methods are applied to emergency monitoring of soil, depending on the purpose ofmonitoring and the phase of emergency. For the main method among them, Information 6
describes the standard sampling and preparation methods and matters to be noted. This chapter
describes how to prepare and store surface soil samples for measuring radioactivity
concentration and deposits. In the method provided in this chapter, wet soil is to be measured
as is without drying, in order to prevent contamination inside rooms, and measurement
containers used are small containers. This method is also applicable to river sediment, lake
sediment, and sea sediment.
8.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Small containers (capacity: about 100 mL)
 Polyethylene bags for sealing measurement containers
 Laboratory spoon (preferably disposable type) Ethanol Pure water*1
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers
 Disposable masks
 Large filter (roughly 60 cm × 60 cm)
 Plastic sheet (plastic bag may be used instead) Ruler Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer)*2 (With the operation panel, top
plate, etc. covered by wrap films, etc. to prevent contamination of the surface)
8.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves andlab coats to prevent exposure and contamination.
(b) Check the sampling location, sampling date, sampling conditions, etc.*3 *4 and assign
identification numbers to the samples.
(c) Place a survey meter as close as possible to the samples and measure radiation levels tofind samples with potentially high radioactivity. Assume the dead time for whenmeasured using a germanium semiconductor detector based on the sample volume and*1 Confirm in advance the pure water is free of radioactive materials.
*2 Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.
*3: Note that sampling area is required for deriving deposits. For the calculation method, refer to 8.6.
*4: A method to directly collect samples by pressing small containers into the ground surface is available, but samples

collected in this manner have significant unevenness in radioactivity concentration unless mixed well, as shown in Figure
6.1 in Information 6.
Therefore, to ensure the homogeneity of the sample, there has been a case of taking collected samplesout of small
containers into polyethylene bags, mixing the samples well in the bags, and placing the samples back into the small
containers to present as samples for measurement.

39

radiation level, and adjust the sample volume so that the dead time can be about 10% orlower as much as possible, and select a measurement container sized for the sample
volume. *5 Select small containers for measurement if the radiation levels from thesamples are high.
(d) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take proper measures accordingly. Measures include storing highradiation level samples that are separated from low radiation level samples, andcontrolling the time for workers to handle the samples to reduce exposure. The samples
which are expected to have high radioactivity should be treated separately to prevent
unnecessary exposure and cross contamination.
8.3 Sample preparation method
8.3.1 Matters to be noted in sample preparation(a) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take measures accordingly. Measures include storing highradiation level samples that are separated from low radiation level samples, andcontrolling the time for workers to handle the samples to reduce exposure. Place a plastic
sheet on a covered workbench, further place large filters on top of it, and work on themseparately for each sample.*6(e) To prevent spreading of contamination from the sample, it is desirable to separate hot
work through direct contact with the sample from cold work through indirect contact,
and to separate workers and workbenches for hot work and cold work as far as possible.

*5: For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which provides
data for each model.
*6: Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.

40

8.3.2 Filling measurement container with sample(a) Measure the weight of samples carried in, and record it.*7(b) Remove any large plant pieces, tree roots, stones, etc. from the samples.*8(Photograph 8.1)(c) Mix the sample well in a bag*9 . (Photograph 8.2)(d) Write or attach the necessary data (e.g., sample identification number) to asmall container, and measure and record the tare weight of the small container.
(e) While paying attention to the homogeneity of the sample, fill the small
container with thesample without gaps using a laboratory spoon.
(Photograph 8.3)(f) Lightly press and level the surface of the sample.
(g) Place a cap on the small container, measure the height of the sample and record it.
(h) Thoroughly wipe the outer surface of the container with a paper towel
moistened with pure water, ethanol, etc.
(i) Measure the weight of the small container, derive the weight of the sample bysubtracting the tare weight measured above, and record it.
(j) To prevent contamination of measurement equipment, place the small container
in a polyethylene bag, remove air, tie the bag opening to seal it (ensure no
creases at the bottom of the container), and present it as a sample formeasurement.
(k) If necessary, calculate the dry soil rate by the method described in 8.5.

Photograph 8.1
Foreign matters removed

Photograph 8.2
Mixing a sample*7: If the samples are watery, remove water following 8.4.
*8: Remove relatively large pieces of foreign matter. If monitoring is performed forthe purpose of measuring deposits at

multiple locations, some sampling sites may not be ideal bare lands and samples may always contain grass. In such a case,samples are to be prepared without removing plants. In addition, in some cases samples are collected separately for soil
surface plants and litter (e.g., fallen leaves and branches on the ground) and soil to measure radioactivity concentration ofeach sample. Ifthat is the case, sampling and pretreatment need to be performed according to the purpose of the study.
*9: If the samples are placed in polyethylene jars, take them out into polyethylene bags.

41

Photograph 8.3
Small container filled with a sample (soil)
8.4 Pretreatment of watery samples
8.4.1 Instruments and tools to be used
 Instruments and tools listed in 8.1
 Büchner funnel Filtration flask
 Aspirator
 Filter paper (preferably those conforming to JIS Standard No. 2)
8.4.2 Removal of water(a) Measure the weight of samples carried in, and record it.
(b) Assemble a Büchner funnel, filtration flask and aspirator, and place filter
paper inside the funnel. (Photograph 8.4)(c) Place a sample in the funnel, and start filtration.*10 (Photograph 8.5)(d) When filtration is completed, place the sample into a polyethylene bag and measure
the wet soil weight. (Photograph 8.6)(e) Follow the step (3) onward in 8.3.2.
(f) Calculate the dry soil rate by the method described in 8.5.*11*10: Handle the filtrate with care, as its radioactivity concentration may be high.
*11: If measurement using a survey meter, etc. suggests that the sample’s radioactivity concentration is high, pay extra

attention not to contaminate other samples.

42

Photograph 8.4
Büchner funnel with filter paper placed
insidePhotograph 8.6

Photograph 8.5
Filtration in progress (seasediment)

Sample dewatered by filtration(sea sediment)
8.5 Calculation of dry soil rate
8.5.1 Instruments and tools to be used
 Instruments and tools listed in 8.1
 Drying oven
 Desiccator Glass beaker or porcelain crucible
 Heat-resistant tray
8.5.2 Procedure(a) Measure the tare weight of glass beaker.
(b) Place at least 10 g of wet soil sample in the glass beaker, and measure theweight. Calculate the wet soil weight by subtracting the tare weight measuredin (1) from this weight.
(c) Dry the sample in a drying oven set to 105°C until the sample’s mass becomes
constant.*12 *13 (Photograph 8.7)(d) Place the sample in a desiccator, and measure the weight after cooling. Derive
the dry soil weight by subtracting the tare weight measured in (1) from this
*12: Placing the glass beaker on a heat-resistant tray may help in preventing the drying oven from being contaminated.
*13: If a hot air dryer is to be used, radioactive particles may scatter around and contaminate the dryer or the laboratory. Pay

attention to the air flow rate, and perform decontamination (wiping) inside the dryer as necessary.

43weight.
(e) Dry soil rate is defined as the ratio of dry soil weight to wet soil weight ([Dry soil
weight]/[Wet soil weight] × 100 (%)).

Photograph 8.7
Dried soil sample (sea sediment)
8.6 Calculation of deposits
After measurement using a germanium semiconductor detector, calculate the deposits per
square meter using the formula below. Note that this formula requires a sampling area, whichneeds to be checked when the sample is carried in.
1
𝐴𝑠 ± Δ𝐴𝑠 = (𝐴𝑤 ± Δ𝐴𝑤 ) × W × × 104
𝑆
2
As: Deposits per square meter (Bq/m )ΔAs: Counting statistics-based uncertainty of As
Aw: Radioactivity concentration per 1 kg of sample (Bq/kg)
ΔAw: Counting statistics-based uncertainty of Aw
W: Collected sample weight (kg)S
: Sampling area (cm2)
8.7 Storage of samples
8.7.1 Storage for a relatively short period of time
Store sample-containing small containers as they are, or placing them into a polyethylene
bag or a container.
8.7.2 Long-term storage(a) Store sample-containing small containers as they are or placing them into apolyethylene bag or a container, or dry the samples following the method provided in theRadioactivity Measurement Series No. 13 Pretreatment of Samples for Instrumental
Analysis using Germanium Detector, etc. (Reference 3). Note that contamination of othersamples needs to be prevented by, for example, washing and cleaning instruments, tools
and equipment after use, if samples with high radioactivity concentration are to be dried.
(b) When storing dried samples, place them in a polyethylene bag or a container, and store
in a low-humidity environment (e.g., inside a desiccator) or by taking measures toprevent contact with air as much as possible.

44

Chapter 9 Vegetables
This chapter describes how to prepare and store vegetables as samples for measurement. In
the method provided in this chapter, assuming assay of radioactive materials in food and drinks
based on OIL6, vegetables are washed with water to remove soil, etc. and chopped into small
pieces. As a reference, the results of a study on how much radioactive materials are removed
from vegetables by washing with water are provided in Information 7. Measurement containers
used are Marinelli beakers or small containers. Table 9.1 shows examples of vegetables to be
used as samples. Note that this method is applicable to yomogi (Artemisia princeps), etc. when
they are consumed, but the method described in Chapter 21 shall be followed if they are
analyzed as an indicator organism.
Table 9.1 Example vegetables
Category

ExamplesFruit vegetables

Tomato, bell pepper

Immature peas and beans

Green bean, green pea

Non-heading leaf vegetables

Spinach, Japanese mustard spinach

Heading leaf vegetables

Chinese cabbage, cabbage

Stem vegetables (excluding allium vegetables)

Asparagus

Flower vegetables

Broccoli, cauliflower

Allium vegetables

Scallion, onion

Potatoes

Potato, taro

Root vegetables (excluding potatoes)

Carrot, white radish (root part)

9.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)
 Cutter*1, scissors, kitchen knife*2 (preferably disposable type) Inner bags for Marinelli beaker Polyethylene bags for sealing measurement containers
 Laboratory spoon (preferably disposable type) Plastic tape
 Thread seal tape Paper towels
 Ethanol Pure water*3
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers*1: Washcutter blades with ethanol, etc. before use, because some cutter blades are coated with oil toprevent rusting. Disposable scalpels may be used instead.
*2: It is desirable to use disposable cutter blades to avoid cross-contamination, but a kitchen knife may have to be used to cut

hard samples. Use cutting tools as appropriate with paying extra attention to safety.
*3: Confirm in advance the pure water is free of radioactive materials.

45 Disposable masks
 Large filter (roughly 60 cm × 60 cm)
 Plastic sheet (plastic bag may be used instead) Paper plate (substitute for cutting board and tray)
 Ruler Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer)*4 (With the operation panel, top plate,etc. covered by wrap films, etc. to prevent contamination of the surface)
9.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves andlab coats to prevent exposure and contamination.
(b) Check the location and date of purchase or the location of production and date ofcollection, and assign identification numbers to the samples.
(c) Place a survey meter as close as possible to the samples and measure radiation levels tofind samples with potentially high radioactivity. The required amount of sample is 50 g
or more (thevolume will be 100 mL or more) for small containers and 1 kg or more (thevolume will be 2 L or more) for Marinelli beakers. Assume the dead time when measured
using a germanium semiconductor detector based on the sample volume and radiationlevel, and adjust the sample volume so that the dead time can be about 10% or lower as
much as possible, and select a measurement container sized for the sample volume.*5
Select small containers for measurement if the radiation levels from the samples are high.
(d) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take measures accordingly. Measures include storing high radiationlevel samples that are separated from low radiation level samples, and controlling thetime for workers to handle the samples to reduce exposure. The samples which are
expected to have high radioactivity should be treated separately to prevent unnecessary
exposure and cross contamination.
9.3 Sample preparation method
9.3.1 Matters to be noted in sample preparation(a) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Place a plastic sheet on a covered workbench, further place large filters on top of it, and*4: Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.
*5 For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which provides
data for each model.

46

work on them separately for each sample.*6(e) To prevent spreading of contamination from the sample, it is desirable to separate hot
work thatinvolves direct contact of the sample from cold work that does not involve directcontact, and it is desirable to separate workers and workbenches between hot work andcold work.
(f) Once preparation is completed for one sample, wrap disposable instruments and tools
with large filters and discard.*7
9.3.2 Sample washing and separation of edible part
(1) Fruit vegetables, immature peas and beans, non-heading leaf vegetables, heading leaf
vegetables, stem vegetables (excluding allium vegetables), flower vegetables, and allium
vegetables(a) Brush off any excess soil at the root part in advance.
(b) Referring to the edible part column in Table 9.2, remove any parts that are not usuallypresented for consumption (for fruit vegetables, remove non-edible parts after washing).
(Photograph 9.1)(c) Referring to the washing method column in Table 9.2, wash the sample.*8(Photograph 9.2)(d) Visually confirm that soil, etc. has been removed from the sample to the levelsuitable to bepresented for consumption.
(e) Remove excess water using paper towels. (Photograph 9.3)(f) Cut the samples into small pieces (about 1-2 cm) using a cutter, etc.*9 (Photograph 9.4)

Photograph 9.1
Parts not presented
for consumption removed(Chinese cabbage)

Photograph 9.2
Washing with water(Chinese cabbage)*6 Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.
*7 Discard disposable cutter blades, etc. separately.
*8 Confirm in advance the tap water to be used for washing is free of radioactive materials. If tap water contains radioactive

materials, use pure water instead after confirming no radioactive materials are contained.
*9

If the samples are soft, they may be broken into small pieces by hand.

47

Photograph 9.4
Sample cut into small pieces(Chinese cabbage)

Photograph 9.3
Removing water(Chinese cabbage)(2) Potatoes and root vegetables (excluding potatoes)(a) Brush off soil, and separate into the root part and stem and leaf part.
(b) Referring to the washing method column in Table 9.2, wash the sample.
(Photograph 9.5)(c) Visually confirm that soil, etc. has been removed from the sample to the levelsuitable to bepresented for consumption.
(d) Remove excess water using paper towels. (Photograph 9.6)(e) Referring to the edible part column in Table 9.2, remove any parts that are not usuallypresented for consumption. (Photograph 9.7)(f) Cut the samples into small pieces (about 1-2 cm) using a cutter, etc. (Photograph 9.8)

Photograph 9.5
Washing with water(potato)Photograph 9.6
Removing water(potato)48

Photograph 9.8
Sample cut into small pieces(potato)Photograph 9.7
Parts not presented
for consumption Removed(potato)Table 9.2 Edible part sectioning method and washing method by vegetable category
Category

ExamplesFruit vegetables

Tomato, bell pepper

Immature peas and beans

Green bean, green pea

Edible part sectioning
methodAfter washing, remove allparts (e.g., calyx, seeds)
that are not served for
consumption.
(Photograph 9.9)

Washing method

Remove the calyx.

Cut off the root part.
(For spinach, remove
Wash under runningfibrous roots.)
tap waterfor about
Remove outer leaves and
20 seconds.
Heading leaf vegetables Chinese cabbage, cabbage the core that is not for
consumption.
Stem vegetables(excluding allium
Asparagus
Stemvegetables)
Remove leaves.
Flower vegetables
Broccoli, cauliflower(Photograph 9.10)
Remove inedible scale
Allium vegetables
Scallion, onion
leaves and fibrous roots.
As is if the skin is
Wash with tap
Potatoes
Potato, taro
consumed, or peel the skinwater to remove
if the skin is not consumed.
soil, etc.
Remove fibrous roots, andRoot vegetables
as is if the skin is consumed
Carrot, white radish(excluding potatoes)or peel the skin if the skin
is not consumed.
Non-heading leaf
vegetables

Spinach,Japanesemustard spinach49

Photograph 9.10
Edible part separated(broccoli)

Photograph 9.9
Edible part separated(bell pepper)

9.3.3 Filling measurement container with sample(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any gaps. (Usedisposablebags to prevent contamination of the wall of the measurement container.)(b) Write or attach the necessary data (e.g., sample identification number) to the Marinelli
beaker, and measure and record the tare weight of the Marinelli beaker, lid and inner bag.
(c) While paying attention to the homogeneity of the sample, place a sample into theMarinelli beaker up to the marked line without gaps. (Photograph 9.11)(d) Lightly press and level the surface of the sample at the marked line. Then, measure theweight of the Marinelli beaker and lid along with the sample, derive the weight of thesample by subtracting the tare weight measured above, and record it.
(e) Seal the inner bag of Marinelli beaker using plastic tape.*10(f) Place the lid on the Marinelli beaker, and seal with plastic tape. (Photograph 9.12)(g) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel moistenedwith pure water, ethanol, etc.
(h) To prevent contamination of measurement equipment, place the Marinelli beaker in apolyethylene bag, remove air, tie the bag opening to seal it, and present it as a sample formeasurement.

Photograph 9.11
Marinelli beaker filled with asample(bell pepper)

Photograph 9.12
The lid fixed with plastic tape(bell pepper)*10: A rubber band, cable tie, etc. may be used instead.

50

(2) In the case of using small containers(a) To prevent leakage, wrap thread seal tape around the threaded part of small container.
(b) Write or attach the necessary data (e.g., sample identification number) to a small
container, and measure and record the tare weight of the small container.
(c) While paying attention to the homogeneity of the sample, fill the small container
with the sample without gaps using a laboratory spoon.
(Photographs 9.13 to 9.18)(d) Lightly press and level the surface of the sample.
(e) Place a cap on the small container, measure the height of the sample and record it.
(f) Thoroughly wipe the outer surface of the container with a paper towel moistenedwith pure water, ethanol, etc.
(g) Measure the weight of the small container, derive the weight of the sample bysubtracting the tare weight measured above, and record it.
(h) To prevent contamination of measurement equipment, place the small container
in a polyethylene bag, remove air, tie the bag opening to seal it (ensure no
creases at the bottom of the container), and present it as a sample formeasurement.

Photograph 9.13
Small container filled with a sample(green bean)

Photograph 9.14
Small container filled with a sample(spinach)

Photograph 9.15
Small container filled with a sample(asparagus)

Photograph 9.16
Small container filled with a sample(broccoli)

51

Photograph 9.17
Small container filled with a sample(potato)Photograph 9.18
Small container filled with a sample(carrot)

9.4 Storage of samples
9.4.1 Storage for a relatively short period of time(a) Samples prepared using Marinelli beakers: place sample-containing inner bags into apolyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing measurement
containersinto a polyethylene bag or a container.
(c) In either case, store samples in a refrigerator, freezer, or cool dark place to prevent
decomposition.
9.4.2 Long-term storage(a) Dry and ash samples by the methods provided in the Radioactivity Measurement SeriesNo. 13 Pretreatment of Samples for Instrumental Analysis using Germanium Detector,
etc. (Reference 3) and Radioactivity Measurement Series No. 16 Method for Sampling
Environmental Materials (Reference 4). (Prevent contamination of other samples by,for example, washing and cleaning instruments, tools and equipment after use, if theradioactivity concentration of the sample is high.)(b) Place ashed samples in a polyethylene bag or a container, and store in a low-humidity
environment (e.g., inside a desiccator) or by taking measures to prevent contact with air
as much as possible.

52

Chapter 10 Fruit
This chapter describes how to prepare and store fruit (e.g., mandarin orange, apple, persimmon,
grape, strawberry) as samples for measurement. In the method provided in this chapter, samples
are washed with water to remove dust, etc. and chopped into small pieces. Measurement
containers used are Marinelli beakers or small containers.
10.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)
 Cutter *1, scissors, kitchen knife*2 (preferably disposable type) Inner bags for Marinelli beaker Polyethylene bags for sealing measurement containers
 Laboratory spoon (preferably disposable type) Plastic tape
 Thread seal tape Paper towels
 Ethanol Pure water*3
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers
 Disposable masks
 Large filter (roughly 60 cm × 60 cm)
 Plastic sheet (plastic bag may be used instead) Paper plate (substitute for cutting board and tray)
 Ruler Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer)*4 (With the operation panel, top
plate, etc. covered by wrap films, etc. to prevent contamination of the surface)
10.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves andlab coats to prevent exposure and contamination.
(b) Check the location and date of purchase or the location of production and date ofcollection, and assign identification numbers to the samples.
(c) Place a survey meter as close as possible to the samples and measure radiation levels tofind samples with potentially high radioactivity. The required amount of sample is 50 g
or more (thevolume will be 100 mL or more) for small containers and 1 kg or more (the*1: Wash cutter blades with ethanol, etc. before use, because some cutter blades arecoated with oil to prevent rusting.

Disposable scalpels may be used instead.
*2: It is desirable to use disposable cutter blades to avoid cross-contamination, but a kitchen knife may have to be used to cut

hard samples. Use cutting tools as appropriate with paying extra attention to safety.
*3: Confirm in advance the pure water is free of radioactive materials.
*4: Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.

53

volume will be 2 L or more) for Marinelli beakers. Assume the dead time when measured
using a germanium semiconductor detector based on the sample volume and radiationlevel, and adjust the sample volume so that the dead time can be about 10% or lower as
much as possible, and select a measurement container sized for the sample volume.*5
Select small containers for measurement if the radiation levels from the samples are high.
(d) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take measures accordingly. Measures include storing highradiation level samples that are separated from low radiation level samples, andcontrolling the time for workers to handle the samples to reduce exposure. The samples
which are expected to have high radioactivity should be treated separately to prevent
unnecessary exposure and cross contamination.
10.3 Sample preparation method
10.3.1 Matters to be noted in sample preparation(a) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Place a plastic sheet on a covered workbench, further place large filters on top of it, andwork on them separately for each sample.*6(e) To prevent spreading of contamination from the sample, it is desirable to separate hot
work through direct contact of the sample from cold work through indirect contact, and
it is desirable to separate workers and workbenches between hot work and cold work(f) Once preparation is completed for one sample, wrap disposable instruments and tools
with large filters and discard.*7
10.3.2 Sample washing and separation of edible part(a) Wash with tap water*8 to remove dust. (Photograph 10.1)
Note that washing is not required for fruit whose peel is not presented for consumption,such as mandarin orange and banana.
(b) Visually confirm that soil, etc. has been removed from the sample to the levelsuitable to be presented for consumption.
(c) Remove excess water using paper towels. (Photograph 10.2)(d) Referring to Table 10.1, remove any parts that are not usually presented for
consumption. (Photograph 10.3)*5: For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which provides
data for each model.
*6: Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.
*7: Discard disposable cutter blades, etc. separately.
*8: Confirm in advance the tap water to be used for washing is free of radioactive materials. If tap water contains radioactive

materials, use pure water instead after confirming no radioactive materials are contained.

54

(e) Cut the samples into small pieces (about 1-2 cm) using a cutter, etc.*9(Photograph 10.4)

Photograph 10.1
Washing with water(grape)Photograph 10.2
Removing water(grape)Photograph 10.3
Parts not presented for consumption
removed (grape)

Photograph 10.4
Sample cut into small pieces(grape)Table 10.1 Edible part sectioning
Example sample

Edible part sectioning method

Mandarin orange, etc.

Persimmon

Remove peels.
Remove the calyx, core, and base part of peduncle *1010 .
(Photograph 10.5)
Remove the calyx and seeds. (Photograph 10.6)

Grape

Remove the peduncle 10 . (Photograph 10.7)Remove seeds as necessary.

Strawberry

Remove the calyx. (Photograph 10.8)

Other

Remove parts not presented for consumption.

Apple, etc.

*9: If the samples are soft, they may be broken into small pieces by hand.
*10: The part where the stalk joins the fruit.

55

Photograph 10.5
Edible part separated(apple)Photograph 10.6
Edible part separated (persimmon)

Photograph 10.7
Edible part separated(grape)Photograph 10.8
Edible part separated(strawberry)

10.3.3 Filling measurement container with sample(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any gaps. (Usedisposablebags to prevent contamination of the wall of the measurement container.)(b) Write or attach the necessary data (e.g., sample identification number) to the Marinelli
beaker, and measure and record the tare weight of the Marinelli beaker, lid and inner bag.
(c) While paying attention to the homogeneity of the sample, place a sample into theMarinelli beaker up to the marked line without gaps. (Photograph 10.9)(d) Lightly press and level the surface of the sample at the marked line. Then, measure theweight of the Marinelli beaker and lid along with the sample, derive the weight of thesample by subtracting the tare weight measured above, and record it.
(e) Seal the inner bag of Marinelli beaker using plastic tape.*11(f) Place the lid on the Marinelli beaker, and seal with plastic tape. (Photograph 10.10)(g) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel moistenedwith pure water, ethanol, etc.
(h) To prevent contamination of measurement equipment, place the Marinelli beaker in apolyethylene bag, remove air, tie the bag opening to seal it, and present it as a sample formeasurement.

*11: A rubber band, cable tie, etc. may be used instead.

56

Photograph 10.9
Marinelli beaker filled with a sample(strawberry)

Photograph 10.10
The lid fixed with plastic tape(strawberry)(2) In the case of using small containers(a) To prevent leakage, wrap thread seal tape around the threaded part of small container.
(b) Write or attach the necessary data (e.g., sample identification number) to a small container,
and measure and record the tare weight of the small container.
(c) While paying attention to the homogeneity of the sample, fill the small container with thesample without gaps using a laboratory spoon.(Photographs 10.11 to 10.13)(d) Lightly press and level the surface of the sample.
(e) Place a cap on the small container, measure the height of the sample and record it.
(f) Thoroughly wipe the outer surface of the container with a paper towel moistened withpure water, ethanol, etc.
(g) Measure the weight of the small container, derive the weight of the sample by subtracting
the tare weight measured above, and record it.
(h) To prevent contamination of measurement equipment, place the small container in apolyethylene bag, remove air, tie the bag opening to seal it (ensure no creases at thebottom of the container), and present it as a sample for measurement.

Photograph 10.12
Small container filled with a sample(grape)Photograph 10.11
Small container filled with a sample(apple)57

Photograph 10.13
Small container filled with a sample(strawberry)
10.4 Storage of samples
10.4.1 Storage for a relatively short period of time(a) Samples prepared using Marinelli beakers: place sample-containing inner bags into
apolyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing measurement
containers into a polyethylene bag or a container.
(c) In either case, store samples in a refrigerator, freezer, or cool dark place to prevent
decomposition.
10.4.2 Long-term storage(a) Dry and ash samples by the methods provided in the Radioactivity Measurement SeriesNo. 13 Pretreatment of Samples for Instrumental Analysis using Germanium Detector,
etc. (Reference 3) and Radioactivity Measurement Series No. 16 Method for Sampling
Environmental Materials (Reference 4). (Prevent contamination of other samples by,for example, washing and cleaning instruments, tools and equipment after use, if theradioactivity concentration of the sample is high.)(b) Place ashed samples in a polyethylene bag or a container, and store in a low-humidity
environment (e.g., inside a desiccator) or by taking measures to prevent contact with air
as much as possible.

58

Chapter 11 Tea leaves
This chapter describes how to prepare and store tea leaves as samples for measurement. In themethod provided in this chapter, samples are to be filled into measurement containers as they
are, in a raw state, without washing.*1 Measurement containers used are Marinelli beakers or
small containers.
11.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)
 Inner bags for Marinelli beaker Polyethylene bags for sealing measurement containers
 Laboratory spoon (preferably disposable type) Plastic tape
 Thread seal tape Paper towels
 Ethanol Pure water*2
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers
 Disposable masks
 Large filter (roughly 60 cm × 60 cm)
 Plastic sheet (plastic bag may be used instead) Paper plate (substitute for tray)
 Ruler Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer)*3 (With the operation panel, top
plate, etc. covered by wrap films, etc. to prevent contamination of the surface)
11.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves andlab coats to prevent exposure and contamination.
(b) Check the location and date of purchase or the location of production and date ofcollection, and assign identification numbers to the samples.
(c) Check and record the sample status (fresh or dried; raw tea or crude tea). Also be mindfulof the unit of radioactivity concentration to be reported (examples: Bq/kg fresh, Bq/kg
dry).
(d) Place a survey meter as close as possible to the samples and measure radiation levels tofind samples with potentially high radioactivity. The required amount of sample is 50 g
or more (the volume will be 100 mL or more) for small containers and 1 kg or more (the*1 Tea leaves are not washed because processing of tea leaves usually does not have a washing process. If tea leaves are to be

used for drinking, conduct measurement on liquid tea according to the Testing Methods for Radioactive Cesium in Food,
Ministry of Health, Labour and Welfare (2012) (Reference 19).
*2 Confirm in advance the pure water is free of radioactive materials.
*3 Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.

59

volume will be 2 L or more) for Marinelli beakers. Assume the dead time when measured
using a germanium semiconductor detector based on the sample volume and radiationlevel, and adjust the sample volume so that the dead time can be about 10% or lower as
much as possible, and select a measurement container sized for the sample volume.*4
Select small containers for measurement if the radiation levels from the samples are high.
(e) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take measures accordingly. Measures include storing high radiationlevel samples that are separated from low radiation level samples, and controlling thetime for workers to handle the samples to reduce exposure. The samples which are
expected to have high radioactivity should be treated separately to prevent unnecessary
exposure and cross contamination.
11.3 Sample preparation method
11.3.1 Matters to be noted in sample preparation(a) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Place a plastic sheet on a covered workbench, further place large filters on top of it, andwork on them separately for each sample.*5(e) To prevent spreading of contamination from the sample, it is desirable to separate hot
work through direct contact of the sample from cold work through indirect contact, and
it is desirable to separate workers and workbenches between hot work and cold work.
(f) Once preparation is completed for one sample, wrap disposable instruments and tools
with large filters and discard.
11.3.2 Sample washing and separation of edible part(a) Do not wash samples. (Photograph 11.1)(b) If the samples were provided in a state of buds and leaves attached to branches, pickthe buds and leaves off the branches by hand.
(Photograph 11.2)(c) Present buds and leaves without foreign matters (e.g., spider web) as a sample(remove any parts with foreign matters from the sample). (Photographs 11.3 and 11.4)*4 For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which provides
data for each model.
*5 Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.

60

Photograph 11.1
Sample (as carried in)(tea leaves)Photograph 11.2
Picking buds and leaves(tea leaves)Photograph 11.3
Foreign matters removed(tea leaves)Photograph 11.4
Sample after picking buds, leaves, andforeign matters(tea leaves)

11.3.3 Filling measurement container with sample(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any gaps.
(Use disposable bags to prevent contamination of the wall of the measurement
container.)(b) Write or attach the necessary data (e.g., sample identification number) to theMarinelli beaker, and measure and record the tare weight of the Marinelli
beaker, lid and inner bag.
(c) While paying attention to the homogeneity of the sample, place a sample into
the Marinelli beaker up to the marked line without gaps.
(d) Lightly press and level the surface of the sample at the marked line. Then,measure the weight of the Marinelli beaker and lid along with the sample, derive
the weight of the sample by subtracting the tare weight measured above, andrecord it.
(e) Seal the inner bag of Marinelli beaker using plastic tape.*6(f) Place the lid on the Marinelli beaker, and seal with plastic tape.
(g) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel
moistened with pure water, ethanol, etc.

*6

: A rubber band, cable tie, etc. may be used instead.

61

(h) To prevent contamination of measurement equipment, place the Marinelli
beaker in a polyethylene bag, remove air, tie the bag opening to seal it, andpresent it as a sample for measurement.
(2) In the case of using small containers(a) To prevent leakage, wrap thread seal tape around the threaded part of small container.
(b) Write or attach the necessary data (e.g., sample identification number) to a small
container, and measure and record the tare weight of the small container.
(c) While paying attention to the homogeneity of the sample, fill the small container
with the sample without gaps using a laboratory spoon.
(Photograph 11.5)(d) Lightly press and level the surface of the sample.
(e) Place a cap on the small container, measure the height of the sample and record it.
(f) Thoroughly wipe the outer surface of the container with a paper towel moistenedwith pure water, ethanol, etc.
(g) Measure the weight of the small container, derive the weight of the sample bysubtracting the tare weight measured above, and record it.
(h) To prevent contamination of measurement equipment, place the small container
in a polyethylene bag, remove air, tie the bag opening to seal it (ensure no
creases at the bottom of the container), and present it as a sample formeasurement.

Photograph 11.5
Small container filled with a sample(tea leaves)
11.4 Storage of samples
11.4.1 Storage for a relatively short period of time(a) Samples prepared using Marinelli beakers: place sample-containing inner bags into apolyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing measurement
containersinto a polyethylene bag or a container.
(c) In either case, store samples in a refrigerator, freezer, or cool dark place to prevent
decomposition.
11.4.2 Long-term storage62

(a) Dry and ash samples by the methods provided in the Radioactivity Measurement SeriesNo. 13 Pretreatment of Samples for Instrumental Analysis using Germanium Detector,
etc. (Reference 3) and Radioactivity Measurement Series No. 16 Method for Sampling
Environmental Materials (Reference 4). (Prevent contamination of other samples by,for example, washing and cleaning instruments, tools and equipment after use, if theradioactivity concentration of the sample is high.)(b) Place ashed samples in a polyethylene bag or a container, and store in a low-humidity
environment (e.g., inside a desiccator) or by taking measures to prevent contact with air
as much as possible.

63

Chapter 12 Grains
This chapter describes how to prepare and store grains as samples for measurement. In themethod provided in this chapter, samples are to be filled into measurement containers as they
are, without washing. Measurement containers used are Marinelli beakers or small containers.
Note that, when samples are collected during the harvest season, the method provided in thischapter is applicable not only to polished rice (white rice) and unpolished rice (brown rice) but
also, as necessary, to unhulled rice, wheats and buckwheats.
12.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)
 Inner bags for Marinelli beaker Polyethylene bags for sealing measurement containers
 Laboratory spoon (preferably disposable type) Plastic tape
 Thread seal tape Paper towels
 Ethanol Pure water*1
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers
 Disposable masks
 Large filter (roughly 60 cm × 60 cm)
 Plastic sheet (plastic bag may be used instead) Paper plate (substitute for tray)
 Ruler Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer)*2 (With the operation panel, top
plate, etc. covered by wrap films, etc. to prevent contamination of the surface)
12.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves
and lab coats to prevent exposure and contamination.
(b) Check the location and date of purchase or the location of production and date ofcollection, and assign identification numbers to the samples.
(c) Place a survey meter as close as possible to the samples and measure radiation levels tofind samples with potentially high radioactivity. The required amount of sample is 100
g or more (the volume will be 100 mL or more) for small containers and 2 kg or more(the volume will be 2 L or more) for Marinelli beakers. Assume the dead time whenmeasured using a germanium semiconductor detector based on the sample volume andradiation level, and adjust the sample volume so that the dead time can be about 10%
or lower as much as possible, and select a measurement container sized for the sample*1: Confirm in advance the pure water is free of radioactive materials.
*2: Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.

64

volume.*3 Select small containers for measurement if the radiation levels from thesamples are high.
(d) Ascertain the contamination situation of the sample from the result of measurement
using the survey meter, and take measures accordingly. Measures include storing highradiation level samples that are separated from low radiation level samples, andcontrolling the time for workers to handle the samples to reduce exposure. The samples
which are expected to have high radioactivity should be treated separately to prevent
unnecessary exposure and cross contamination.
12.3 Sample preparation method
12.3.1 Matters to be noted in sample preparation(a) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Place a plastic sheet on a covered workbench, further place large filters on top of it, andwork on them separately for each sample.*4(e) To prevent spreading of contamination from the sample, it is desirable to separate hot
work that involves direct contact of the sample from cold work that does not involve
direct contact, and it is desirable to separate workers and workbenches between hot
work and cold work.
(f) Once preparation is completed for one sample, wrap disposable instruments and tools
with large filters and discard.
12.3.2 Filling measurement container with sample(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any gaps. (Usedisposablebags to prevent contamination of the wall of the measurement container.)(b) Write or attach the necessary data (e.g., sample identification number) to the Marinelli
beaker, and measure and record the tare weight of the Marinelli beaker, lid and inner bag.
(c) While paying attention to the homogeneity of the sample, place a sample into theMarinelli beaker up to the marked line without gaps. (Photograph 12.1)(d) Lightly press and level the surface of the sample at the marked line. Then, measure theweight of the Marinelli beaker and lid along with the sample, derive the weight of thesample by subtracting the tare weight measured above, and record it.
(e) Seal the inner bag of Marinelli beaker using plastic tape.*5(f) Place the lid on the Marinelli beaker, and seal with plastic tape. (Photograph 12.2)*3 For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which provides
data for each model.
*4 Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.
*5 A rubber band, cable tie, etc. may be used instead.

65

(g) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel moistenedwith pure water, ethanol, etc.
(h) To prevent contamination of measurement equipment, place the Marinelli beaker in apolyethylene bag, remove air, tie the bag opening to seal it, and present it as a sample
for measurement.

Photograph 12.1
Marinelli beaker filled with a sample(polished rice)

Photograph 12.2
The lid fixed with plastic tape(polished rice)(2) In the case of using small containers(a) To prevent leakage, wrap thread seal tape around the threaded part of small container.
(b) Write or attach the necessary data (e.g., sample identification number) to a small
container, and measure and record the tare weight of the small container.
(c) While paying attention to the homogeneity of the sample, fill the small container
with thesample without gaps using a laboratory spoon. (Photograph 12.3)(d) Lightly press and level the surface of the sample.
(e) Place a cap on the small container, measure the height of the sample and record it.
(f) Thoroughly wipe the outer surface of the container with a paper towel moistened withpure water, ethanol, etc.
(g) Measure the weight of the small container, derive the weight of the sample by subtracting
the tare weight measured above, and record it.
(h) To prevent contamination of measurement equipment, place the small container in apolyethylene bag, remove air, tie the bag opening to seal it (ensure no creases at thebottom of the container), and present it as a sample for measurement.

Photograph 12.3
Small container filled with a sample(polished rice)66

12.4 Storage of samples
12.4.1 Storage for a relatively short period of time(a) Samples prepared using Marinelli beakers: place sample-containing inner bags into
apolyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing measurement
containersinto a polyethylene bag or a container.
(c) In either case, store samples in a refrigerator, freezer, or cool dark place to prevent
decomposition.
12.4.2 Long-term storage(a) Dry and ash samples by the methods provided in the Radioactivity Measurement SeriesNo. 13 Pretreatment of Samples for Instrumental Analysis using Germanium Detector,
etc. (Reference 3) and Radioactivity Measurement Series No. 16 Method for Sampling
Environmental Materials (Reference 4). (Prevent contamination of other samples by,for example, washing and cleaning instruments, tools and equipment after use, if theradioactivity concentration ofthe sample is high.)(b) Place ashed samples in a polyethylene bag or a container, and store in a low-humidity
environment (e.g., inside a desiccator) or by taking measures to prevent contact with air
as much as possible.

67

Chapter 13 Peas and beans
This chapter describes how to prepare and store peas and beans as samples for measurement.
In the method provided in this chapter, samples are to be filled into measurement containers as
they are, without washing. Measurement containers used are Marinelli beakers or small
containers. For peas and beans presented in the pod for consumption (e.g., green bean), follow
the method provided in Chapter 9.
13.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)
 Cutter *1, scissors, kitchen knife *2 (preferably disposable type) Inner bags for Marinelli beaker Polyethylene bags for sealing measurement containers
 Laboratory spoon (preferably disposable type) Plastic tape
 Thread seal tape Paper towels
 Ethanol Pure water*3
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers
 Disposable masks
 Large filter (roughly 60 cm × 60 cm)
 Plastic sheet (plastic bag may be used instead) Paper plate (substitute for cutting board and tray)
 Ruler Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer)*4 (With the operation panel, top
plate,etc. covered by wrap films, etc. to prevent contamination of the surface)
13.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves andlab coats to prevent exposure and contamination.
(b) Check the location and date of purchase or the location of production and date ofcollection, and assign identification numbers to the samples.
(c) Place a survey meter as close as possible to the samples and measure radiation levels tofind samples with potentially high radioactivity. The required amount of sample is 50 g
or more (the volume will be 100 mL or more) for small containers and 1 kg or more (the*1: Wash cutter blades with ethanol, etc. before use, because some cutter blades are coated with oil to prevent rusting.

Disposable scalpels may be used instead.
*2: It is desirable to use disposable cutter blades to avoid cross-contamination, but a kitchen knife mayhave to be used to

cut hard samples. Use cutting tools as appropriate with paying extra attention to safety.
*3: Confirm in advance the pure water is free of radioactive materials.
*4: Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.

68

volume will be 2 L or more) for Marinelli beakers. Assume the dead time when measured
using a germanium semiconductor detector based on the sample volume and radiationlevel, and adjust the sample volume so that the dead time can be about 10% or lower as
much as possible, and select a measurement container sized for the sample volume.*5
Select small containers for measurement if the radiation levels from the samples are high .
(d) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take measures accordingly. Measures include storing high radiationlevel samples that are separated from low radiation level samples, and controlling thetime for workers to handle the samples to reduce exposure. The samples which are
expected to have high radioactivity should be treated separately to prevent unnecessary
exposure and cross contamination.
13.3 Sample preparation method
13.3.1 Matters to be noted in sample preparation(a) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Place a plastic sheet on a covered workbench, further place large filters on top of it, andworkon them separately for each sample.*6(e) To prevent spreading of contamination from the sample, it is desirable to separate hot
work through direct contact of the sample from cold work through direct contact, and it
is desirable to separate workers and workbenches between hot work and cold work.
(f) Once preparation is completed for one sample, wrap disposable instruments and tools
with large filters and discard.*7
13.3.2 Sample washing and separation of edible part(a) Do not wash samples.
(b) If the samples are in the pod, take the edible part out using a cutter, etc.
(Photographs 13.1 and 13.2)(c) If necessary, place the samples in a plastic bag, etc. and crush them into small
pieces to facilitate filling into measurement containers.(Photograph 13.3)*5: For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which provides
data for each model.
*6: Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.
*7: Discard disposable cutter blades, etc. separately.

69

Photograph 13.2
Parts not presented
for consumption removed(green soybeans)

Photograph 13.1
Taking out of the pod(green soybeans)

Photograph 13.3
Samples after crushing in a plastic bag(green soybeans)
13.3.3 Filling measurement container with sample(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any gaps. (Usedisposable bags to prevent contamination of the wall of the measurement container.)(b) Write or attach the necessary data (e.g., sample identification number) to the Marinelli
beaker, and measure and record the tare weight of the Marinelli beaker, lid and inner bag.
(c) While paying attention to the homogeneity of the sample, place a sample into theMarinelli beaker up to the marked line without gaps. (Photograph 13.4)(d) Lightly press and level the surface of the sample at the marked line. Then, measure
the weight of the Marinelli beaker and lid along with the sample, derive the weight ofthe sample by subtracting the tare weight measured above, and record it.
(e) Seal the inner bag of Marinelli beaker using plastic tape.*8(f) Place the lid on the Marinelli beaker, and seal with plastic tape. (Photograph 13.5)(g) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel moistenedwith pure water, ethanol, etc.
(h) To prevent contamination of measurement equipment, place the Marinelli beaker in apolyethylene bag, remove air, tie the bag opening to seal it, and present it as a sample
for measurement.
: A rubber band, cable tie, etc. may be used instead.

*870

Photograph 13.4
Marinelli beaker filled with a sample(green soybeans)

Photograph 13.5
The lid fixed with plastic tape(green soybeans)(2) In the case of using small containers(a) To prevent leakage, wrap thread seal tape around the threaded part of small container.
(b) Write or attach the necessary data (e.g., sample identification number) to a small
container, and measure and record the tare weight of the small container.
(c) While paying attention to the homogeneity of the sample, fill the small container
with the sample without gaps using a laboratory spoon.(Photograph 13.6)(d) Lightly press and level the surface of the sample.
(e) Place a cap on the small container, measure the height of the sample and record it.
(f) Thoroughly wipe the outer surface of the container with a paper towel moistenedwith pure water, ethanol, etc.
(g) Measure the weight of the small container, derive the weight of the sample bysubtracting the tare weight measured above, and record it.
(h) To prevent contamination of measurement equipment, place the small container
in a polyethylene bag, remove air, tie the bag opening to seal it (ensure no
creases at the bottom of the container), and present it as a sample formeasurement.

Photograph 13.6
Small container filled with a sample(green soybeans)7113.4 Storage of samples
13.4.1 Storage for a relatively short period of time(a) Samples prepared using Marinelli beakers: place sample-containing inner bags into apolyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing measurement
containersinto a polyethylene bag or a container.
(c) In either case, store samples in a refrigerator, freezer, or cool dark place to prevent
decomposition.
13.4.2 Long-term storage(a) Dry and ash samples by the methods provided in the Radioactivity Measurement Series
No.13 Pretreatment of Samples for Instrumental Analysis using Germanium Detector, etc.
(Reference 3) and Radioactivity Measurement Series No. 16 Method for Sampling Environmental
Materials (Reference 4). (Prevent contamination of other samples by, for example, washing andcleaning instruments, tools and equipment after use, if the radioactivity concentration of thesample is high.)(b) Place ashed samples in a polyethylene bag or a container, and store in a low-humidity
environment (e.g., inside a desiccator) or by taking measures to prevent contact with air
as much as possible.

72

Chapter 14 Mushrooms
This chapter describes how to prepare and store mushrooms (e.g., shiitake, maitake (hen of
the woods)) as samples for measurement. In the method provided in this chapter, samples arelightly wiped and chopped into small pieces. Measurement containers used are Marinelli
beakers or small containers.
14.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)
 Cutter*1, scissors, kitchen knife*2 (preferably disposable type) Inner bags for Marinelli beaker Polyethylene bags for sealing measurement containers
 Laboratory spoon (preferably disposable type) Plastic tape
 Thread seal tape Paper towels
 Ethanol Pure water*3
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers
 Disposable masks
 Large filter (roughly 60 cm × 60 cm)
 Plastic sheet (plastic bag may be used instead) Paper plate (substitute for cutting board and tray)
 Ruler Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer)*4 (With the operation panel, top
plate, etc. covered by wrap films, etc. to prevent contamination of the surface)
14.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves andlab coats to prevent exposure and contamination.
(b) Check the location and date of purchase or the location of production and date ofcollection, and assign identification numbers to the samples.
(c) Place a survey meter as close as possible to the samples and measure radiation levels tofind samples with potentially high radioactivity. The required amount of sample is 50 g
or more (the volume will be 100 mL or more) for small containers and 1 kg or more (thevolume will be 2 L or more) for Marinelli beakers. Assume the dead time when measured*1: Wash cutter blades with ethanol, etc. before use, because some cutter blades are coated with oil toprevent rusting.

Disposable scalpels may be used instead.
*2: It is desirable to use disposable cutter blades to avoid cross-contamination, but a kitchen knife mayhave to be used to

cut hard samples. Use cutting tools as appropriate with paying extra attention to safety.
*3: Confirm in advance the pure water is free of radioactive materials.
*4 Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.

73

using a germanium semiconductor detector based on the sample volume and radiationlevel, and adjust the sample volume so that the dead time can be about 10% or lower as
much as possible, and select a measurement container sized for the sample volume.*5
Select small containers for measurement if the radiation levels from the samples are high.
(d) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take measures accordingly. Measures include storing highradiation level samples that are separated from low radiation level samples, andcontrolling the time for workers to handle the samples to reduce exposure. The samples
which are expected to have high radioactivity should be treated separately to prevent
unnecessary exposure and cross contamination.
14.3 Sample preparation method
14.3.1 Matters to be noted in sample preparation(a) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Place a plastic sheet on a covered workbench, further place large filters on top of it, andworkon them separately for each sample.*6(e) To prevent spreading of contamination from the sample, it is desirable to separate hot
work through direct contact of the sample from cold work through indirect contact, and
it is desirable to separate workers and workbenches between hot work and cold work to
the extent possible.
(f) Once preparation is completed for one sample, wrap disposable instruments and tools
with large filters and discard.*7
14.3.2 Sample washing and separation of edible part(a) Remove the hard base part. (Photograph 14.1)(b) Lightly wipe the surface using paper towels moistened with tap water *8 .
(Photograph 14.2)(c) Visually confirm that soil, etc. has been removed from the sample to the level suitable
to bepresented for consumption.
(d) Cut the samples into small pieces (about 1-2 cm) using a cutter, etc.*9(Photographs 14.3 and14.4)*5: For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which provides
data for each model.
*6: Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.
*7: Discard disposable cutter blades, etc. separately.
*8: Confirm in advance the tap water to be used for washing is free of radioactive materials. If tap water contains radioactive

materials, use pure water instead after confirming no radioactive materials are contained.
*9: If the samples are soft, they may be broken into small pieces by hand.

74

Photograph 14.1
Hard base part removed(shiitake)

Photograph 14.2
Wiping (shiitake)

Photograph 14.3
Cutting sample into small pieces(shiitake)

Photograph 14.4
Sample cut into small pieces(shiitake)14.3.3 Filling measurement container with sample(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any gaps. (Usedisposable bags to prevent contamination of the wall of the measurement container.)(b) Write or attach the necessary data (e.g., sample identification number) to the Marinelli
beaker, and measure and record the tare weight of the Marinelli beaker, lid and inner bag.
(c) While paying attention to the homogeneity of the sample, place a sample into theMarinelli beaker up to the marked line without gaps. (Photograph 14.5)(d) Lightly press and level the surface of the sample at the marked line. Then, measure
theweight of the Marinelli beaker and lid along with the sample, derive the weight of thesample by subtracting the tare weight measured above, and record it.
(e) Seal the inner bag of Marinelli beaker using plastic tape.*10(f) Place the lid on the Marinelli beaker, and seal with plastic tape. (Photograph 14.6)(g) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel moistenedwith pure water, ethanol, etc.
(h) To prevent contamination of measurement equipment, place the Marinelli beaker in apolyethylene bag, remove air, tie the bag opening to seal it, and present it as a sample formeasurement.
: A rubber band, cable tie, etc. may be used instead.

*10

75

Photograph 14.6
The lid fixed with plastic tape(shiitake)

Photograph 14.5
Marinelli beaker filled with a sample(shiitake)(2) In the case of using small containers(a) To prevent leakage, wrap thread seal tape around the threaded part of small container.
(b) Write or attach the necessary data (e.g., sample identification number) to a small
container, and measure and record the tare weight of the small container.
(c) While paying attention to the homogeneity of the sample, fill the small container withthe sample without gaps using a laboratory spoon.(Photograph 14.7)(d) Lightly press and level the surface of the sample.
(e) Place a cap on the small container, measure the height of the sample and record it.
(f) Thoroughly wipe the outer surface of the container with a paper towel moistened withpure water, ethanol, etc.
(g) Measure the weight of the small container, derive the weight of the sample by subtracting
the tare weight measured above, and record it.
(h) To prevent contamination of measurement equipment, place the small container in apolyethylene bag, remove air, tie the bag opening to seal it (ensure no creases at thebottom of the container), and present it as a sample for measurement.

Photograph 14.7
Small container filledwith a sample(shiitake)76

14.4 Storage of samples
14.4.1 Storage for a relatively short period of time(a) Samples prepared using Marinelli beakers: place sample-containing inner bags into apolyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing measurement
containersinto a polyethylene bag or a container.
(c) In either case, store samples in a refrigerator, freezer, or cool dark place to prevent
decomposition.
14.4.2 Long-term storage(a) Dry and ash samples by the methods provided in the Radioactivity Measurement Series
No.13 Pretreatment of Samples for Instrumental Analysis using Germanium Detector,
etc. (Reference 3) and Radioactivity Measurement Series No. 16 Method for Sampling
Environmental Materials (Reference 4). (Prevent contamination of other samples by, forexample, washing and cleaning instruments, tools and equipment after use, if theradioactivity concentration of the sample is high.)(b) Place ashed samples in a polyethylene bag or a container, and store in a low-humidity
environment (e.g., inside a desiccator) or by taking measures to prevent contact with air
as much as possible.

77

Chapter 15 Seaweeds
This chapter describes how to prepare and store seaweeds (e.g., kelp, seaweed, hijiki,Gelidiaceae (agar weed)) as samples for measurement. In the method provided in this chapter,
samples are washed with water to remove sand, etc. and chopped into small pieces.
Measurement containers used are Marinelli beakers or small containers. Note that, whensamples like hondawara (Sargassum fulvellum) are analyzed as an indicator organism, themethod described in Chapter 21 shall be followed.
15.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)
 Cutter*1, scissors, kitchen knife*2 (preferably disposable type) Inner bags for Marinelli beaker Polyethylene bags for sealing measurement containers
 Laboratory spoon (preferably disposable type) Plastic tape
 Thread seal tape Paper towels
 Strainer, etc. (for draining water)
 Ethanol Pure water*3
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers
 Disposable masks
 Large filter (roughly 60 cm × 60 cm)
 Plastic sheet (plastic bag may be used instead) Paper plate (substitute for cutting board and tray)
 Ruler Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer)*4 (With the operation panel, top plate,etc. covered by wrap films, etc. to prevent contamination of the surface)
15.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves andlab coats to prevent exposure and contamination.
(b) Check the location and date of purchase or the location of production and date ofcollection, and assign identification numbers to the samples.

*1: Wash cutter blades with ethanol, etc. before use, because some cutter blades are coated with oil to prevent rusting.

Disposable scalpels may be used instead.
*2: It is desirable to use disposable cutter blades to avoid cross-contamination, but a kitchen knife mayhave to be used to

cut hard samples. Use cutting tools as appropriate with paying extra attention to safety.
*3: Confirm in advance the pure water is free of radioactive materials.
*4: Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.

78

(c) Place a survey meter as close as possible to the samples and measure radiation levels tofind samples with potentially high radioactivity. The required amount of sample is 50 g
or more (the volume will be 100 mL or more) for small containers and 1 kg or more (thevolume will be 2 L or more) for Marinelli beakers. Assume the dead time when measured
using a germanium semiconductor detector based on the sample volume and radiationlevel, and adjust the sample volume so that the dead time can be about 10% or lower as
much as possible, and select a measurement container sized for the sample volume.*5
Select small containers for measurement if the radiation levels from the samples are high .
(d) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take measures accordingly. Measures include storing high radiationlevel samples that are separated from low radiation level samples, and controlling thetime for workers to handle the samples to reduce exposure.
15.3 Sample preparation method
15.3.1 Matters to be noted in sample preparation(a) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Place a plastic sheet on a covered workbench, further place large filters on top of it, andworkon them separately for each sample.*6(e) To prevent spreading of contamination from the sample, it is desirable to separate hot
work through direct contact of the sample from cold work through indirect contact, and
it is desirable to separate workers and workbenches for between work and cold work to
the extent possible.
(f) Once preparation is completed for one sample, wrap disposable instruments and tools
with large filters and discard.*7
15.3.2 Sample washing and separation of edible part(a) Remove the base part and any foreign matters.*8(b) Wash well using tap water*9 * 1 0 . (Photograph 15.1)(c) Visually confirm that sand, etc. has been removed from the sample to the level suitable
to bepresented for consumption.
*5: For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which provides
data for each model.
*6: Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.
*7: Discard disposable cutter blades, etc. separately.
*8: Seaweeds often have other flora and fauna attached on the body and small rock pieces at the base; carefully remove them.
*9: Confirm in advance the tap water to be used for washing is free of radioactive materials. If tap water contains radioactive

materials, use pure water instead after confirming no radioactive materials are contained.
*10: Do not leave the sample in tap water for a long period of time.

79

(d) Drain well using a strainer, etc. (Photograph 15.2)(e) Cut the samples into small pieces (about 1-2 cm) using a cutter, etc.
(Photographs 15.3 and15.4)

Photograph 15.1
Washing with water(seaweed)

Photograph 15.2
Draining water(seaweed)

Photograph 15.3
Cutting sample into small pieces(seaweed)

Photograph 15.4
Sample cut into small pieces(seaweed)

15.3.3 Filling measurement container with sample(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any gaps. (Usedisposable bags to prevent contamination of the wall of the measurement container.)(b) Write or attach the necessary data (e.g., sample identification number) to the Marinelli
beaker, and measure and record the tare weight of the Marinelli beaker, lid and inner bag.
(c) While paying attention to the homogeneity of the sample, place a sample into theMarinelli beaker up to the marked line without gaps. (Photograph 15.5)(d) Lightly press and level the surface of the sample at the marked line. Then, measure
theweight of the Marinelli beaker and lid along with the sample, derive the weight of thesample by subtracting the tare weight measured above, and record it.
(e) Seal the inner bag of Marinelli beaker using plastic tape.*11(f) Place the lid on the Marinelli beaker, and seal with plastic tape. (Photograph 15.6)(g) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel moistened: A rubber band, cable tie, etc. may be used instead.

*11

80

with pure water, ethanol, etc.
(h) To prevent contamination of measurement equipment, place the Marinelli beaker in apolyethylene bag, remove air, tie the bag opening to seal it, and present it as a sample formeasurement.

Photograph 15.6
The lid fixed with plastic tape(seaweed)

Photograph 15.5
Marinelli beaker filled with a sample(seaweed)(2) In the case of using small containers(a) To prevent leakage, wrap thread seal tape around the threaded part of small container.
(b) Write or attach the necessary data (e.g., sample identification number) to a small
container, and measure and record the tare weight of the small container.
(c) While paying attention to the homogeneity of the sample, fill the small container
with thesample without gaps using a laboratory spoon. (Photograph 15.7)(d) Lightly press and level the surface of the sample.
(e) Place a cap on the small container, measure the height of the sample and record it.
(f) Thoroughly wipe the outer surface of the container with a paper towel moistened withpure water, ethanol, etc.
(g) Measure the weight of the small container, derive the weight of the sample by subtracting
the tare weight measured above, and record it.
(h) To prevent contamination of measurement equipment, place the small container in apolyethylene bag, remove air, tie the bag opening to seal it (ensure no creases at thebottom of the container), and present it as a sample for measurement.

Photograph 15.7
Small container filled with a sample(seaweed)8115.4 Storage of samples
15.4.1 Storage for a relatively short period of time(a) Samples prepared using Marinelli beakers: place sample-containing inner bags into apolyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing measurement
containersinto a polyethylene bag or a container.
(c) In either case, store samples in a refrigerator, freezer, or cool dark place to prevent
decomposition.
15.4.2 Long-term storage(a) Dry and ash samples by the methods provided in the Radioactivity Measurement Series
No.13 Pretreatment of Samples for Instrumental Analysis using Germanium Detector,
etc. (Reference 3) and Radioactivity Measurement Series No. 16 Method for Sampling
Environmental Materials (Reference 4). (Prevent contamination of other samples by, forexample, washing and cleaning instruments, tools and equipment after use, if theradioactivity concentration of the sample is high.)(b) Place ashed samples in a polyethylene bag or a container, and store in a low-humidity
environment (e.g., inside a desiccator) or by taking measures to prevent contact with air
as much as possible.

82

Chapter 16 Meats
This chapter describes how to prepare and store meats (e.g., beef, pork, chicken) as samples
for measurement. In the method provided in this chapter, samples are boned and chopped into
small pieces. Measurement containers used are Marinelli beakers or small containers.
16.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)
 Cutter*1, scissors, kitchen knife*2 (preferably disposable type) Inner bags for Marinelli beaker Polyethylene bags for sealing measurement containers
 Laboratory spoon (preferably disposable type) Plastic tape
 Thread seal tape Paper towels
 Ethanol Pure water*3
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers
 Disposable masks
 Large filter (roughly 60 cm × 60 cm)
 Plastic sheet (plastic bag may be used instead) Paper plate (substitute for cutting board and tray)
 Ruler Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer)*4 (With the operation panel, top
plate, etc. covered by wrap films, etc. to prevent contamination of the surface)
16.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves andlab coats to prevent exposure and contamination.
(b) Check the location and date of purchase or the location of production and date ofcollection, and assign identification numbers to the samples.
(c) Place a survey meter as close as possible to the samples and measure radiation levels tofind samples with potentially high radioactivity. The required amount of sample is 100
g or more (the volume will be 100 mL or more) for small containers and 2 kg or more(the volume will be 2 L or more) for Marinelli beakers. Assume the dead time whenmeasured using a germanium semiconductor detector based on the sample volume and*1: Wash cutter blades with ethanol, etc. before use, because some cutter blades are coated with oil to prevent rusting.

Disposable scalpels may be used instead.
*2: It is desirable to use disposable cutter blades to avoid cross-contamination, but a kitchen knife mayhave to be used to

cut hard samples. Use cutting tools as appropriate with paying extra attention to safety.
*3: Confirm in advance the pure water is free of radioactive materials.
*4: Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.

83

radiation level, and adjust the sample volume so that the dead time can be about 10% orlower as much as possible, and select a measurement container sized for the sample
volume.*5 Select small containers for measurement if the radiation levels from thesamples are high.
(d) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take measures accordingly. Measures include storing highradiation level samples that are separated from low radiation level samples, andcontrolling the time for workers to handle the samples to reduce exposure. The samples
which are expected to have high radioactivity should be treated separately to prevent
unnecessary exposure and cross contamination.
16.3 Sample preparation method
16.3.1 Matters to be noted in sample preparation(a) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Place a plastic sheet on a covered workbench, further place large filters on top of it, andworkon them separately for each sample.*6(e) To prevent spreading of contamination from the sample, it is desirable to separate hot
work through direct contact of the sample from cold work through indirect contact, and
it is desirable to separate workers and workbenches between hot work and cold.
(f) Once preparation is completed for one sample, wrap disposable instruments and tools
with large filters and discard.*7
16.3.2 Sample washing and separation of edible part(a) Do not wash samples.
(b) If the samples have bones, remove the bones.

*5: For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which provides
data for each model.
*6: Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Usingsimplified

disposable coverings for each sample will reduce the frequency of covering replacement.
*7: Discard disposable cutter blades, etc. separately.

84

(c) Cut the samples into small pieces (about 1-2 cm) using a cutter, etc.
(Photographs 16.1 and16.2)

Photograph 16.1
Cutting sample into small pieces(beef)

Photograph 16.2
Sample cut into small pieces(beef)

16.3.3 Filling measurement container with sample(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any gaps. (Usedisposable bags to prevent contamination of the wall of the measurement container.)(b) Write or attach the necessary data (e.g., sample identification number) to the Marinelli
beaker, and measure and record the tare weight of the Marinelli beaker, lid and inner bag.
(c) While paying attention to the homogeneity of the sample, place a sample into theMarinelli beaker up to the marked line without gaps. (Photograph 16.3)(d) Lightly press and level the surface of the sample at the marked line. Then, measure
theweight of the Marinelli beaker and lid along with the sample, derive the weight of thesample by subtracting the tare weight measured above, and record it.
(e) Seal the inner bag of Marinelli beaker using plastic tape.*8(f) Place the lid on the Marinelli beaker, and seal with plastic tape. (Photograph 16.4)(g) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel moistenedwith pure water, ethanol, etc.
(h) To prevent contamination of measurement equipment, place the Marinelli beaker in apolyethylene bag, remove air, tie the bag opening to seal it, and present it as a sample formeasurement.

*8: A rubber band, cable tie, etc. may be used instead.

85

Photograph 16.4
The lid fixed with plastic tape
(beef)

Photograph 16.3
Marinelli beaker filled with a sample(beef)(2) In the case of using small containers(a) To prevent leakage, wrap thread seal tape around the threaded part of small container.
(b) Write or attach the necessary data (e.g., sample identification number) to a small
container, and measure and record the tare weight of the small container.
(c) While paying attention to the homogeneity of the sample, fill the small container
with thesample without gaps using a laboratory spoon. (Photograph 16.5)(d) Lightly press and level the surface of the sample.
(e) Place a cap on the small container, measure the height of the sample and record it.
(f) Thoroughly wipe the outer surface of the container with a paper towel moistened withpure water, ethanol, etc.
(g) Measure the weight of the small container, derive the weight of the sample by subtracting
the tare weight measured above, and record it.
(h) To prevent contamination of measurement equipment, place the small container in apolyethylene bag, remove air, tie the bag opening to seal it (ensure no creases at thebottom of the container), and present it as a sample for measurement.

Photograph 16.5
Small container filled with a sample(beef)

86

16.4 Storage of samples
16.4.1 Storage for a relatively short period of time(a) Samples prepared using Marinelli beakers: place sample-containing inner bags into apolyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing measurement
containersinto a polyethylene bag or a container.
(c) In either case, store samples in a refrigerator, freezer, or cool dark place to prevent
decomposition.
16.4.2 Long-term storage(a) Dry and ash samples by the methods provided in the Radioactivity Measurement Series
No.13 Pretreatment of Samples for Instrumental Analysis using Germanium Detector,
etc. (Reference 3) and Radioactivity Measurement Series No. 16 Method for Sampling
Environmental Materials (Reference 4). (Prevent contamination of other samples by, forexample, washing and cleaning instruments, tools and equipment after use, if theradioactivity concentration of the sample is high.)(b) Place ashed samples in a polyethylene bag or a container, and store in a low-humidity
environment (e.g., inside a desiccator) or by taking measures to prevent contact with air
as much as possible.

87

Chapter 17 Cow’s milkThis chapter describes how to prepare and store raw milk and pasteurized and homogenizedcommercial milk as samples for measurement. Measurement containers used are Marinelli
beakers orsmall containers.
17.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)
 Inner bags for Marinelli beaker Polyethylene bags for sealing measurement containers
 Piston pipette Plastic tape
 Thread seal tape Paper towels
 Ethanol Pure water *1
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers
 Disposable masks
 Large filter (roughly 60 cm × 60 cm)
 Plastic sheet (plastic bag may be used instead) Ruler Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer)*2 (With the operation panel, top
plate, etc. covered by wrap films, etc. to prevent contamination of the surface)
17.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves andlab coats to prevent exposure and contamination.
(b) Check the location and date of purchase or the location of production and date ofcollection, and assign identification numbers to the samples.
(c) Place a survey meter as close as possible to the samples and measure radiation levels tofind samples with potentially high radioactivity. The required amount of sample is 100 gor more (the volume will be 100 mL or more) for small containers and 2 kg or more (thevolume will be 2 L or more) for Marinelli beakers. Assume the dead time when measured
using a germanium semiconductor detector based on the sample volume and radiationlevel, and adjust the sample volume so that the dead time can be about 10% or lower as
much as possible, and select a measurement container sized for the sample volume.*3*1: Confirm in advance the pure water is free of radioactive materials.
*2: Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.
*3: For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which provides
data for each model.

88Select small containers for measurement if the radiation levels from the samples are high.
(d) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take measures accordingly. Measures include storing high radiationlevel samples that are separated from low radiation level samples, and controlling thetime for workers to handle the samples to reduce exposure. The samples which are
expected to have high radioactivity should be treated separately to prevent unnecessary
exposure and cross contamination.
17.3 Sample preparation method
17.3.1 Matters to be noted in sample preparation(a) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Place a plastic sheet on a covered workbench, further place large filters on top of it, andworkon them separately for each sample.*4(e) To prevent spreading of contamination from the sample, it is desirable to separate hot
work through direct contact of the sample from cold work through indirect contact, and
it is desirable to separate workers and workbenches between hot work and cold work to
the extent possible.
(f) Once preparation is completed for one sample, wrap disposable instruments and tools
withlarge filters and discard.
17.3.2 Filling measurement container with sample(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any gaps. (Usedisposable bags to prevent contamination of the wall of the measurement container.)(b) Write or attach the necessary data (e.g., sample identification number) to the Marinelli
beaker, and measure and record the tare weight of the Marinelli beaker, lid and innerbag.
(c) Mix the sample well, and place it in the Marinelli beaker prepared in (2) up to themarkedline. (Photograph 17.1) Use a piston pipette to finely adjust to the marked line.
(d) Measure the weight of the Marinelli beaker and lid along with the sample, derive theweight of the sample by subtracting the tare weight measured above, and record it.
(e) Seal the inner bag of Marinelli beaker using plastic tape.*5(f) Place the lid on the Marinelli beaker, and seal with plastic tape. (Photograph 17.2)(g) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel moistenedwith pure water, ethanol, etc.
(h) To prevent contamination of measurement equipment, place the Marinelli beaker in apolyethylene bag, remove air, tie the bag opening to seal it, and present it as a sample
for measurement.
*4: Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.
*5: A rubber band, cable tie, etc. may be used instead.

89

Photograph 17.1
Marinelli beaker filled with a sample(cow’s milk)

Photograph 17.2
The lid fixed with plastic tape(cow’s
milk)(2) In the case of using small containers(a) To prevent leakage, wrap thread seal tape around the threaded part of small container.
(b) Write or attach the necessary data (e.g., sample identification number) to a small
container, and measure and record the tare weight of the small container.
(c) Mix the sample well, and place approximately 80 g of sample into the small container
prepared in (2). (Photograph 17.3) Use a piston pipette to finely adjust the volume.
(d) Place a cap on the small container, measure the height of the sample and record it.
(e) Thoroughly wipe the outer surface of the container with a paper towel moistened withpure water, ethanol, etc.
(f) Measure the weight of the small container, derive the weight of the sample by subtracting
the tare weight measured above, and record it.
(g) To prevent contamination of measurement equipment, place the small container in apolyethylene bag, remove air, tie the bag opening to seal it (ensure no creases at thebottom of the container), and present it as a sample for measurement.

Photograph 17.3
Small container filled with a sample(cow’s milk)
17.4 Storage of samples
17.4.1 Storage for a relatively short period of time(a) Samples prepared using Marinelli beakers: place sample-containing inner bags into apolyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing measurement
containersinto a polyethylene bag or a container.
90

(c) In either case, store samples in a refrigerator or cool dark place to prevent
decomposition.
17.4.2 Long-term storage(a) Dry and ash cow’s milk samples by the methods provided in the Radioactivity
Measurement Series No. 13 Pretreatment of Samples for Instrumental Analysis using
Germanium Detector, etc. (Reference 3) and Radioactivity Measurement Series No. 16
Method for Sampling Environmental Materials (Reference 4). (Prevent contamination ofother samples by, for example, washing and cleaning instruments, tools and equipment
after use, if the radioactivity concentration of the sample is high.)(b) Place ashed samples in a polyethylene bag or a container, and store in a low-humidity
environment (e.g., inside a desiccator) or by taking measures to prevent contact with air
as much as possible.

91Chapter 18 Dairy productsThis chapter describes how to prepare and store dairy products (e.g., powdered milk, cheese,butter) as samples for measurement. Dairy products come in various forms, such as powder,solid block and liquid, and the preparation method varies depending on the form. Solid block
products are to be cut into small pieces. Measurement containers used are Marinelli beakers or
small containers.
18.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)
 Cutter*1, scissors, kitchen knife*2 (preferably disposable type) Inner bags for Marinelli beaker Polyethylene bags for sealing measurement containers
 Laboratory spoon (preferably disposable type) Graduated cylinder (2 L or 100 mL)
 Piston pipette Plastic tape
 Thread seal tape Paper towels
 Ethanol Pure water*3
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers
 Disposable masks
 Large filter (roughly 60 cm × 60 cm)
 Plastic sheet (plastic bag may be used instead) Paper plate (substitute for cutting board and tray)
 Ruler Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer)*4 (With the operation panel, top
plate, etc. covered by wrap films, etc. to prevent contamination of the surface)
18.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves andlab coats to prevent exposure and contamination.
(b) Check the location and date of purchase or the location of production and date ofcollection, and assign identification numbers to the samples.
(c) Place a survey meter as close as possible to the samples and measure radiation levels to*1: Wash cutter blades with ethanol, etc. before use, because some cutter blades are coated with oil to prevent rusting.

Disposable scalpels may be used instead.
*2: It is desirable to use disposable cutter blades to avoid cross-contamination, but a kitchen knife may have to be used to

cut hard samples. Use cutting tools as appropriate with paying extra attention to safety.
*3: Confirm in advance the pure water is free of radioactive materials.
*4: Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.

92

find samples with potentially high radioactivity. The required amount of sample is 100 gor more (the volume will be 100 mL or more) for small containers and 2 kg or more (thevolume will be 2 L or more) for Marinelli beakers. Assume the dead time when measured
using a germanium semiconductor detector based on the sample volume and radiationlevel, and adjust the sample volume so that the dead time can be about 10% or lower as
much as possible, and select a measurement container sized for the sample volume.*5
Select small containers for measurement if the radiation levels from the samples are high .
(d) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take measures accordingly. Measures include storing high radiationlevel samples that are separated from low radiation level samples, and controlling thetime for workers to handle the samples to reduce exposure. The samples which are
expected to have high radioactivity should be treated separately to prevent unnecessary
exposure and cross contamination.
18.3 Sample preparation method
18.3.1 Matters to be noted in sample preparation(a) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Place a plastic sheet on a covered workbench, further place large filters on top of it, andwork on them separately for each sample.*6(e) To prevent spreading of contamination from the sample, it is desirable to separate hot
work that involves direct contact of the sample from cold work that does not involve
direct contact, and it is desirable to separate workers and workbenches between hot workand cold work to the extent possible.
(f) Once preparation is completed for one sample, wrap disposable instruments and tools
with large filters and discard.*7
18.3.2 Powder products (e.g., powdered milk)(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any gaps.
(Use disposable bags to prevent contamination of the wall of the measurement
container.)(b) Write or attach the necessary data (e.g., sample identification number) to theMarinelli beaker,and measure and record the tare weight of the Marinelli beaker,
lid and inner bag.
*5: For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which
provides data for each model.
*6: Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.
*7: Discard disposable cutter blades, etc. separately.

93

(c) While paying attention to the homogeneity of the sample, place a sample into
the Marinelli beaker up to the marked line without gaps. (Photograph 18.1)(d) Lightly press and level the surface of the sample at the marked line. Then,measure theweight of the Marinelli beaker and lid along with the sample, derive
the weight of the sample by subtracting the tare weight measured above, andrecord it.
(e) Seal the inner bag of Marinelli beaker using plastic tape.*8(f) Place the lid on the Marinelli beaker, and seal with plastic tape. (Photograph 18.2)(g) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel
moistened with pure water, ethanol, etc.
(h) To prevent contamination of measurement equipment, place the Marinelli
beaker in a polyethylene bag, remove air, tie the bag opening to seal it, andpresent it as a sample for measurement.

Photograph 18.2
The lid fixed with plastic tape(powdered milk)

Photograph 18.1
Marinelli beaker filled with a sample(powdered milk)(2) In the case of using small containers(a) To prevent leakage, wrap thread seal tape around the threaded part of small container.
(b) Write or attach the necessary data (e.g., sample identification number) to asmall container,and measure and record the tare weight of the small container.
(c) While paying attention to the homogeneity of the sample, fill the small
container with thesample without gaps using a laboratory spoon.
(d) Lightly press and level the surface of the sample.
(e) Place a cap on the small container, measure the height of the sample and record it.
(f) Thoroughly wipe the outer surface of the container with a paper towel moistenedwith pure water, ethanol, etc.
(g) Measure the weight of the small container, derive the weight of the sample bysubtracting the tare weight measured above, and record it.
(h) To prevent contamination of measurement equipment, place the small container
in a polyethylene bag, remove air, tie the bag opening to seal it (ensure no
creases at the bottom of the container), and present it as a sample formeasurement.

: A rubber band, cable tie, etc. may be used instead.

*8

94

18.3.3 Solid block products (e.g., cheese, butter)(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any
gaps. (Use disposable bags to prevent contamination of the wall of themeasurement container.)(b) Write or attach the necessary data (e.g., sample identification number) to theMarinelli beaker, and measure and record the tare weight of the Marinelli
beaker, lid and inner bag.
(c) Cut the samples into small pieces (about 1-2 cm) using a cutter, etc.
(d) While paying attention to the homogeneity of the sample, place a sample into
the Marinelli beaker up to the marked line without gaps.
(e) Lightly press and level the surface of the sample at the marked line. Then,measure theweight of the Marinelli beaker and lid along with the sample, derive
the weight of the sample by subtracting the tare weight measured above, andrecord it.
(f) Seal the inner bag of Marinelli beaker using plastic tape. *6(g) Place the lid on the Marinelli beaker, and seal with plastic tape.
(h) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel
moistened with pure water, ethanol, etc.
(i) To prevent contamination of measurement equipment, place the Marinelli
beaker in a polyethylene bag, remove air, tie the bag opening to seal it, andpresent it as a sample for measurement.
(2) In the case of using small containers(a) To prevent leakage, wrap thread seal tape around the threaded part of small container.
(b) Write or attach the necessary data (e.g., sample identification number) to asmall container,and measure and record the tare weight of the small container.
(c) Cut the samples into small pieces (about 1-2 cm) using a cutter, etc. (Photograph 18.3)(d) While paying attention to the homogeneity of the sample, fill the small
container with thesample without gaps using a laboratory spoon. (Photograph
18.4)(e) Lightly press and level the surface of the sample.
(f) Place a cap on the small container, measure the height of the sample and record it.
(g) Thoroughly wipe the outer surface of the container with a paper towel moistenedwith pure water, ethanol, etc.
(h) Measure the weight of the small container, derive the weight of the sample bysubtracting the tare weight measured above, and record it.
(i) To prevent contamination of measurement equipment, place the small container
in a polyethylene bag, remove air, tie the bag opening to seal it (ensure no
creases at the bottom of the container), and present it as a sample formeasurement.

95

Photograph 18.3
Cutting sample into small pieces(butter)

Photograph 18.4
Small container filled with a sample(butter)

18.3.4 Liquid products (e.g., condensed milk)
Follow the method described in Chapter 17.
18.4 Storage of samples
18.4.1 Storage for a relatively short period of time(a) Samples prepared using Marinelli beakers: place sample-containing inner bags into apolyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing measurement
containersinto a polyethylene bag or a container.
(c) In either case, store samples in a refrigerator, freezer, or cool dark place to prevent
decomposition.
18.4.2 Long-term storage(d) Dry and ash samples by the methods provided in the Radioactivity Measurement Series
No.13 Pretreatment of Samples for Instrumental Analysis using Germanium Detector,
etc. (Reference 3) and Radioactivity Measurement Series No. 16 Method for Sampling
Environmental Materials (Reference 4). (Prevent contamination of other samples by, forexample, washing and cleaning instruments, tools and equipment after use, if theradioactivity concentration of the sample is high.)(e) Place ashed samples in a polyethylene bag or a container, and store in a low-humidity
environment (e.g., inside a desiccator) or by taking measures to prevent contact with air
as much as possible.

96Chapter 19 Eggs
This chapter describes how to prepare and store chicken eggs as samples formeasurement. Measurement containers used are Marinelli beakers or small containers.
19.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)
 Inner bags for Marinelli beaker Polyethylene bags for sealing measurement containers Container (e.g., beaker, mixing bowl)
 Piston pipette Plastic tape
 Thread seal tape Paper towels
 Ethanol Pure water*1
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers
 Disposable masks
 Large filter (roughly 60 cm × 60 cm)
 Plastic sheet (plastic bag may be used instead) Ruler Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer)*2 (With the operation panel, top
plate, etc. covered by wrap films, etc. to prevent contamination of the surface)
19.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves andlab coats to prevent exposure and contamination.
(b) Check the location and date of purchase or the location of production and date ofcollection, and assign identification numbers to the samples.
(c) Place a survey meter as close as possible to the samples and measure radiation levels tofind samples with potentially high radioactivity. The required amount of sample is 100 gor more (about 2 eggs) for small containers and 2 kg or more (about 30-40 eggs) for
Marinelli beakers. Assume the dead time when measured using a germanium
semiconductor detector based on the sample volume and radiation level, and adjust the
sample volume so that the dead time can be about 10% or lower as much as possible, andselect a measurement container sized for the sample volume.*3 Select small containers*1: Confirm in advance the pure water is free of radioactive materials.
*2: Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.
*3: For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which provides
data for each model.

97

for measurement if the radiation levels from the samples are high .
(d) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take measures accordingly. Measures include storing high radiationlevel samples that are separated from low radiation level samples, and controlling thetime for workers to handle the samples to reduce exposure. The samples which are
expected to have high radioactivity should be treated separately to prevent unnecessary
exposure and cross contamination.
19.3 Sample preparation method
19.3.1 Matters to be noted in sample preparation(a) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Place a plastic sheet on a covered workbench, further place large filters on top of it, andwork on them separately for each sample.*4(e) To prevent spreading of contamination from the sample, it is desirable to separate hot
work through direct contact of the sample from cold work through indirect contact, and it
is desirable to separate workers and workbenches between hot work and cold work to theextent possible.
(f) Once preparation is completed for one sample, wrap disposable instruments and tools
with large filters and discard.
19.3.2 Filling sample for measurement(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any gaps. (Usedisposable bags to prevent contamination of the wall of the measurement container.)(b) Write or attach the necessary data (e.g., sample identification number) to the Marinelli
beaker, and measure and record the tare weight of the Marinelli beaker, lid and innerbag.
(c) Crack eggs into a container (e.g., beaker, mixing bowl) and mix well.
(d) Mix the sample well and place it in the Marinelli beaker prepared in (2) up to themarked line. (Photograph 19.1) Use a piston pipette to finely adjust to the marked line.
(e) Measure the weight of the Marinelli beaker and lid along with the sample, derive theweight of the sample by subtracting the tare weight measured above, and record it.
(f) Seal the inner bag of Marinelli beaker using plastic tape.*5(g) Place the lid on the Marinelli beaker, and seal with plastic tape. (Photograph 19.2)(h) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel moistenedwith pure water, ethanol, etc.
(i) To prevent contamination of measurement equipment, place the Marinelli beaker in apolyethylene bag, remove air, tie the bag opening to seal it, and present it as a sample for*4: Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.
*5: A rubber band, cable tie, etc. may be used instead.

98

measurement.

Photograph 19.1
Marinelli beaker filled with a sample(chicken egg)

Photograph 19.2
The lid fixed with plastic tape(chicken egg)(2) In the case of using small containers(a) To prevent leakage, wrap thread seal tape around the threaded part of small container.
(b) Write or attach the necessary data (e.g., sample identification number) to a small
container, and measure and record the tare weight of the small container.
(c) Crack eggs into a container (e.g., beaker, mixing bowl) and mix well.
(d) Mix the sample well, and place it into the small container prepared in (2). (Photograph19.3)Use a piston pipette to finely adjust the volume.
(e) Place a cap on the small container, measure the height of the sample and record it.
(f) Thoroughly wipe the outer surface of the container with a paper towel moistened withpure water, ethanol, etc.
(g) Measure the weight of the small container, derive the weight of the sample by subtracting
the tare weight measured above, and record it.
(h) To prevent contamination of measurement equipment, place the small container in apolyethylene bag, remove air, tie the bag opening to seal it (ensure no creases at thebottom of the container), and present it as a sample for measurement.

Photograph 19.3
Small container filled with a sample(chicken egg)99

19.4 Storage of samples
19.4.1 Storage for a relatively short period of time(a) Samples prepared using Marinelli beakers: place sample-containing inner bags into apolyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing measurement
containersinto a polyethylene bag or a container.
(c) In either case, store samples in a refrigerator, freezer, or cool dark place to prevent
decomposition.
19.4.2 Long-term storage(a) Dry and ash egg samples by the methods provided in the Radioactivity Measurement
Series No. 13 Pretreatment of Samples for Instrumental Analysis using Germanium
Detector, etc. (Reference 3) and Radioactivity Measurement Series No. 16 Method for
Sampling Environmental Materials (Reference 4). (Prevent contamination of othersamples by, for example, washing and cleaning instruments, tools and equipment afteruse, if the radioactivity concentration of the sample is high.)(b) Place ashed samples in a polyethylene bag or a container, and store in a low-humidity
environment (e.g., inside a desiccator) or by taking measures to prevent contact with air
as much as possible.

100Chapter 20 Seafood
This chapter describes how to prepare and store seafood as samples for measurement. Someseafood is presented without removing any part for the whole to be consumed, while otherseafood is presented after removing viscera. In the latter case, attention needs to be paid to lossof blood, body fluids, etc. during preparation and associated contamination of other samples.
Measurement containers used are Marinelli beakers or small containers. Table 20.1 shows
examples of seafood to be used as samples.
Table 20.1 Seafood example
Category

ExamplesSpratelloides gracilis, whitebait (the whole is consumed)

Fish
Caranginae, mackerel, righteye flounder (the muscle part is consumed)
Shellfish

Asari (Venerupis philippinarum), oyster, shijimi (Corbiculidae)

Cephalopoda

Squid, octopus

Crustaceans

Prawn, shrimp, crab

Echinoderms

Sea cucumber, sea urchin

20.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)
 Cutter*1, scissors, kitchen knife*2 (preferably disposable type) Inner bags for Marinelli beaker Polyethylene bags for sealing measurement containers
 Laboratory spoon (preferably disposable type) Plastic tape
 Thread seal tape Paper towels
 Strainer, etc. (for draining water)
 Ethanol Pure water*3
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers
 Disposable masks
 Large filter (roughly 60 cm × 60 cm)*1: Wash cutter blades with ethanol, etc. before use, because some cutter blades are coated with oil to prevent rusting.

Disposable scalpels may be used instead.
*2: It is desirable to use disposable cutter blades to avoid cross-contamination, but a kitchen knife mayhave to be used to

cut hard samples. Use cutting tools as appropriate with paying extra attention to safety.
*3: Confirm in advance the pure water is free of radioactive materials.

101 Plastic sheet (plastic bag may be used instead) Paper plate (substitute for cutting board and tray)
 Ruler Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer) *44 (With the operation panel, top
plate, etc. covered by wrap films, etc. to prevent contamination of the surface)
20.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves andlab coats to prevent exposure and contamination.
(b) Check the location and date of purchase or the location of production and date ofcollection, and assign identification numbers to the samples.
(c) Place a survey meter as close as possible to the samples and measure radiation levels tofind samples with potentially high radioactivity. The required amount of sample is 100 gor more (the volume will be 100 mL or more) for small containers and 2 kg or more (thevolume will be 2 L or more) for Marinelli beakers Assume the dead time when measured
using a germanium semiconductor detector based on the sample volume and radiationlevel, and adjust the sample volume so that the dead time can be about 10% or lower as
much as possible, and select a measurement container sized for the sample volume.*5
Select small containers for measurement if the radiation levels from the samples are high .
(d) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take measures accordingly. Measures include storing high radiationlevel samples that are separated from low radiation level samples, and controlling thetime for workers to handle the samples to reduce exposure. The samples which are
expected to have high radioactivity should be treated separately to prevent unnecessary
exposure and cross contamination.
20.3 Sample preparation method
20.3.1 Matters to be noted in sample preparation(a) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Place a plastic sheet on a covered workbench, further place large filters on top of it, andworkon them separately for each sample.*6(e) To prevent spreading of contamination from the sample, it is desirable to separate hot*4: Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.
*5: For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which provides
data for each model.
*6: Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.

102

work through direct contact of the sample from cold work through indirect contact, and
it is desirable to separate workers and workbenches between hot work and cold work to
the extent possible.
(f) Once preparation is completed for one sample, wrap disposable instruments and tools
with large filters and discard.*7
20.3.2 Sample washing and separation of edible part
(1) Fish for which the whole is presented for consumption, such as Spratelloides gracilis(a) Quickly wash with tap water*8 to remove any foreign matter on the surface as
early as possible. (Photograph 20.1)(b) Place in a strainer, etc. for 10-15 minutes to drain water. (Photograph 20.2)(c) Fill the drained samples as they are (Photograph 20.3) or after cutting into small
pieces (about 1-2 cm) (Photograph 20.4) into measurement containers.

Photograph 20.1
Washing with water(Spratelloides gracilis)

Photograph 20.2
Draining water(Spratelloides gracilis)

Photograph 20.3
Sample to be filled into measurement
container (as is)(Spratelloides gracilis)

Photograph 20.4
Sample to be filled intomeasurement container(cut into small pieces)(Spratelloides gracilis)*7: Discard disposable cutter blades, etc. separately.
*8: Confirm in advance the tap water to be used for washing is free of radioactive materials. If tap water contains radioactive

materials, use pure water instead after confirming no radioactive materials are contained.

103

(2) Fish for which the muscle part is presented for consumption, such as Caranginae(a) Quickly wash with tap water to remove any foreign matter on the surface as early as
possible.(Photograph 20.5)(b) Remove water using paper towels. (Photograph 20.6)(c) Remove the head, viscera, bones, etc. to have only the muscle part left.*9(Photograph 20.7)(d) Cut the samples into small pieces (about 1-2 cm) using a cutter, etc. (Photograph 20.8)*9: Pay

Photograph 20.5
Washing with water(Caranginae)

Photograph 20.6
Wiping (Caranginae)

Photograph 20.7
Parts not presented
for consumption removed(Caranginae)

Photograph 20.8
Sample cut into small pieces(Caranginae)

attention when separating muscles and viscera to contamination of other tissues by damagingviscera or loss due

to release of body fluids.

104

(3) Shellfish (e.g., asari)(a) In principle, do not remove sand in an emergency, but remove sand if necessary.*10
Record in a form whether sand was removed or not.
(b) Quickly wash with tap water to remove any foreign matter on the surface as early as
possible.(Photograph 20.9)(c) Remove water using paper towels. (Photograph 20.10)(d) Shuck the samples to have only the meat part left.*11 Do not wash the meat part withwater. (Photographs 20.11 and 20.12)(e) If the samples are large-type shellfish and viscera, etc. are not presented for
consumption, cut out the edible part only using a cutter, etc.

Photograph 20.9
Washing with water(asari)Photograph 20.10
Wiping(asari)Photograph 20.11
Shucking(asari)

Photograph 20.12
Shucked sample (asari)*10 Let shellfish to expel sand or mud by immersing overnight freshwater shellfish in fresh water and saltwater shellfish inseawater collected near the sampling site.
*11 In some methods, shellfish is shucked after freezing or using a microwave oven. However, if volatile nuclides such asradioactive iodine are included in the nuclides to be measured, take appropriate measures (e.g., reduce the output (Watt) of
microwave oven not to overheat the sample) to prevent volatile nuclides from volatilizing.

105

(4) Cephalopoda (e.g., squid)(a) Quickly wash with tap water to remove any foreign matter on the surface as early as
possible.(Photograph 20.13)(b) Remove water and slime using paper towels. (Photograph 20.14)(c) Remove the viscera, etc. to have only the muscle part left.*12 (Photograph 20.15)(d) Cut the samples into small pieces (about 1-2 cm) using a cutter, etc. (Photograph 20.16)

Photograph 20.13
Washing with water(squid)

Photograph 20.14
Wiping (squid)

Photograph 20.15
Parts not presented for consumption
removed (squid)

Photograph 20.16
Cutting sample into small pieces(squid)*12 Payattention when separating muscles and viscera to contamination of other tissues by damagingviscera or loss due

to release of body fluids.

106

(5) Crustaceans (e.g., prawn)(a) Quickly wash with tap water to remove any foreign matter on the surface as early as
possible.(Photograph 20.17)(b) Remove water using paper towels. (Photograph 20.18) Place samples for which thewhole is presented for consumption (e.g., shrimp) in a strainer, etc. for 10-15 minutes todrain water.
(c) Shuck the samples to have only the meat part left. (Photograph 20.19) Do not wash themeat part with water. Fill samples for which the whole is presented for consumption (e.g.,
shrimp) into measurement containers as they are without removing the shell.
(d) Cut the samples into small pieces (about 1-2 cm) using a cutter, etc., as necessary.
(Photograph 20.20)

Photograph 20.17
Washing with water(prawn)Photograph 20.18
Wiping(prawn)Photograph 20.19
Parts not presented for consumption
removed (prawn)

Photograph 20.20
Sample cut into small pieces(prawn)107

(6) Echinoderms (e.g., sea cucumber)(a) If needed according to the condition of sampling, let the samples to expel sand or mud
by immersing overnight in seawater collected near the sampling site. Record in a form
whether sand was removed or not.
(b) Quickly wash with tap water to remove any foreign matter on the surface as early as
possible.(Photograph 20.21)(c) Remove water using paper towels. (Photograph 20.22)(d) If viscera, etc. are not presented for consumption, cut out the edible part only using acutter,etc.*13 (Photograph 20.23)(e) Cut the samples into small pieces (about 1-2 cm) using a cutter, etc. (Photograph 20.24)

Photograph 20.21
Washing with water (sea cucumber)Photograph 20.22
Removing water(sea cucumber)Photograph 20.23
Parts not presented for consumption
removed (sea cucumber)Photograph 20.24
Sample cut into small pieces(sea cucumber)*13: Pay

attention when separating muscles and viscera to contamination of other tissues by damagingviscera or loss due

to release of body fluids.

108

20.3.3 Filling measurement container with sample(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any gaps. (Usedisposable bags to prevent contamination of the wall of the measurement container.)(b) Write or attach the necessary data (e.g., sample identification number) to the Marinelli
beaker, and measure and record the tare weight of the Marinelli beaker, lid and inner bag.
(c) While paying attention to the homogeneity of the sample, place a sample into theMarinelli beaker up to the marked line without gaps. (Photograph 20.25)(d) Lightly press and level the surface of the sample at the marked line. Then, measure
theweight of the Marinelli beaker and lid along with the sample, derive the weight of thesample by subtracting the tare weight measured above, and record it.
(e) Seal the inner bag of Marinelli beaker using plastic tape.*14(f) Place the lid on the Marinelli beaker, and seal with plastic tape. (Photograph 20.26)(g) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel moistenedwith pure water, ethanol, etc.
(h) To prevent contamination of measurement equipment, place the Marinelli beaker in apolyethylene bag, remove air, tie the bag opening to seal it, and present it as a sample
for measurement.*15

Photograph 20.26
The lid fixed with plastic tape
(Caranginae)

Photograph 20.25 Marinelli beaker
filled with a sample(Caranginae)(2) In the case of using small containers(a) To prevent leakage, wrap thread seal tape around the threaded part of small container.
(b) Write or attach the necessary data (e.g., sample identification number) to a small
container, and measure and record the tare weight of the small container.
(c) While paying attention to the homogeneity of the sample, fill the small container withthe sample without gaps using a laboratory spoon. (Photographs 20.27 to 20.32)(d) Lightly press and level the surface of the sample.
(e) Place a cap on the small container, measure the height of the sample and record it.
(f) Thoroughly wipe the outer surface of the container with a paper towel moistened withpure water, ethanol, etc.
(g) Measure the weight of the small container, derive the weight of the sample by subtracting
the tare weight measured above, and record it.

*14: A rubber band, cable tie, etc. may be used instead.
*15: If the samples were carried in frozen, return the samples and measurement containers to roomtemperature prior tomeasurement to prevent dew condensation during the measurement.

109

(h) To prevent contamination of measurement equipment, place the small container in apolyethylene bag, remove air, tie the bag opening to seal it (ensure no creases at thebottom of the container), and present it as a sample for measurement. *15

Photograph 20.27
Small container filled with a sample(Spratelloides gracilis)

Photograph 20.28
Small container filled with a sample(Caranginae)

Photograph 20.29
Small container filled with a sample(asari)Photograph 20.30
Small container filled with a sample(squid)Photograph 20.31
Small container filled with a sample(prawn)Photograph 20.32
Small container filled with a sample (seacucumber)11020.4 Storage of samples
20.4.1 Storage for a relatively short period of time(a) Samples prepared using Marinelli beakers: place sample-containing inner bags into apolyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing measurement
containers into a polyethylene bag or a container.
(c) In either case, store samples in a freezer.
20.4.2 Long-term storage(a) Dry and ash samples by the methods provided in the Radioactivity Measurement Series
No.13 Pretreatment of Samples for Instrumental Analysis using Germanium Detector,
etc. (Reference 3) and Radioactivity Measurement Series No. 16 Method for Sampling
Environmental Materials (Reference 4). (Prevent contamination of other samples by, forexample, washing and cleaning instruments, tools and equipment after use, if theradioactivity concentration of the sample is high.)(b) Place ashed samples in a polyethylene bag or a container, and store in a low-humidity
environment (e.g., inside a desiccator) or by taking measures to prevent contact with air
as much as possible.

111

Chapter 21 Indicator organisms (including pasture plants)
This chapter describes how to prepare and store indicator organisms as samples formeasurement. Measurement containers used are Marinelli beakers or small containers. Table
21.1 shows examples of indicator organisms to be used as samples. Note that, if yomogi(Artemisia princeps), seaweeds and mussels are to be analyzed as food, the method describedin Chapters 9, 15, and 20 shall be followed, respectively.
Table 21.1 Example indicator organisms
Category

ExamplesInland indicator organisms

Yomogi, pine needle, cedar leaf

Marine indicatororganisms
Pasture plants

Hondawara, kajime, arame,mussels
Pasture plants

21.1 Equipment, tools, etc. to be needed Scintillation survey meter for gamma-rays (covered by a large plastic bag to prevent
contamination of the surface) Marinelli beakers (capacity: 2 L) or small containers (capacity: about 100 mL)
 Cutter*1, scissors, kitchen knife*2 (preferably disposable type) Inner bags for Marinelli beaker Polyethylene bags for sealing measurement containers
 Laboratory spoon (preferably disposable type) Plastic tape
 Thread seal tape Paper towels
 Strainer, etc. (for draining water)
 Ethanol Pure water*3
 Lab coat (preferably disposable type) Disposable polyethylene or rubber gloves
 Arm covers
 Disposable masks
 Large filter (roughly 60 cm × 60 cm)
 Plastic sheet (plastic bag may be used instead) Paper plate (substitute for cutting board and tray)
 Ruler Electronic balances (shall be able to measure in grams, to the second decimal place;
preferably with a recording function such as a printer)*4 (With the operation panel, top
plate, etc. covered by wrap films, etc. to prevent contamination of the surface)*1: Wash cutter blades with ethanol, etc. before use, because some cutter blades arecoated with oil to prevent rusting.

Disposable scalpels may be used instead.
*2: It is desirable to use disposable cutter blades to avoid cross-contamination, but a kitchen knife may have to be used to cut

hard samples. Use cutting tools as appropriate with paying extra attention to safety.
*3: Confirm in advance the pure water is free of radioactive materials.
*4: Use balances that are properly controlled (e.g., periodically inspected and calibrated). Also, it is recommended to routinely

inspect the balances by, for example, checking the condition using weights before and after use.

112

21.2 Precautions for carrying in samples(a) When carrying in samples, make sure that all workers are wearing disposable gloves andlab coats to prevent exposure and contamination.
(b) Check the location and date of purchase or the location of production and date ofcollection, and assign identification numbers to the samples.
(c) Place a survey meter as close as possible to the samples and measure radiation levels tofind samples with potentially high radioactivity. For inland indicator organisms, somemarine indicator organisms such as hondawara, kajime (Ecklonia cava) and arame(Eisenia bicyclis), and pasture plants, the required amount of sample is 50 g or more (thevolume will be 100 mL or more) for small containers and 1 kg or more (the volume willbe 2 L or more) for Marinelli beakers. For other marine indicator organisms such asmussels, the required amount of sample is 100 g or more (the volume will be 100 mL ormore) for small containers and 2 kg or more (the volume will be 2 L or more) for
Marinelli beakers. Assume the dead time when measured using a germanium
semiconductor detector based on the sample volume and radiation level, and adjust the
sample volume so that the dead time can be about 10% or lower as much as possible,
and select a measurement container sized for the sample volume.*5 Select small
containers for measurement if the radiation levels from the samples are high .
(d) Ascertain the contamination situation of the sample from the result of measurement using
the survey meter, and take measures accordingly. Measures include storing high radiationlevel samples that are separated from low radiation level samples, and controlling thetime for workers to handle the samples to reduce exposure. The samples which are
expected to have high radioactivity should be treated separately to prevent unnecessary
exposure and cross contamination.
21.3 Sample preparation method
21.3.1 Matters to be noted in sample preparation(a) To prevent cross-contamination, determine in advance the order of samples to beprepared, based on the results of survey meter measurements conducted when thesamples were carried in.
(b) If the radiation level of sample is high, in order to minimize the time of handling thesample as much as possible, workers are to check and familiarize themselves with thework flow in advance.
(c) Before starting the work, cover the surfaces inside the room (e.g., floor, workbench) by
the method described in Chapter 2.
(d) Place a plastic sheet on a covered workbench, further place large filters on top of it, andwork on them separately for each sample.*6(e) To prevent spreading of contamination from the sample, it is desirable to separate hot
work through direct contact of the sample from cold work through indirect contact, and
it is desirable to separate workers and workbenches between hot work and cold work to
the extent possible.
(f) Once preparation is completed for one sample, wrap disposable instruments and tools*5: For the relationship between dose rates at the surface of sample measured using a survey meter and radioactivity

concentration, refer to the Calibration of NaI (Tl) Scintillation Survey Meter Used for Measurement of Radioactive Cesiumin Food in Emergencies (2nd Edition) issued by the Japan Radioisotope Association in 2011 (Reference 16), which provides
data for each model.
*6: Replacing coverings of workbench and floor surfaces requires a considerable amount of labor. Using simplified disposable

coverings for each sample will reduce the frequency of covering replacement.

113

with large filters and discard.*7
21.3.2 Sample washing and part selection(1) Inland indicator organisms (e.g., yomogi, pine needles)(a) Present those without withered leaves and foreign matter as a sample (remove withered
leaves and any parts with foreign matter from the sample). Samples are not to be washedin principle. (Photograph 21.1)(b) If the samples were provided with branches and stalks, pick off leaves only.
(Photograph 21.2)(c) Cut the samples into small pieces (about 1-2 cm) using a cutter, etc.
(Photographs 21.3 and 21.4)

Photograph 21.1
Withered leaves, foreign matters, etc.
removed (pine needles)

Photograph 21.2
Removing branches and stalks(pine needles)

Photograph 21.3
Cutting sample into small pieces(pine needles)

Photograph 21.4
Sample cut into small pieces(pine needles)*7: Discard disposable cutter blades, etc. separately.

114

(2) Marine indicator organisms (e.g., hondawara, kajime, arame)(a) Drain well using a strainer, etc. Samples are not to be washed in principle.
(Photograph 21.5)(b) Remove the base part and any foreign matter.*8 (Photograph 21.6)(c) Cut the samples into small pieces (about 1-2 cm) using a cutter, etc.
(Photographs 21.7 and 21.8)

Photograph 21.5
Draining water (hondawara)

Photograph 21.6
Removing the base part andforeign matter (hondawara)

Photograph 21.7
Parts to be presented as a sample selected(hondawara)

Photograph 21.8
Sample cut into small pieces(hondawara)(3) Marine indicator organisms (e.g., mussels)

Shuck the samples to have only the meat part left. Do not wash the meat part with water.
(4) Pasture plants(a) Brush off any excess soil at the root part in advance.
(b) Present those without withered leaves and foreign matter as a sample (remove
withered leaves and any parts with foreign matter from the sample). Samples are not to
be washed in principle.
(c) Cut the samples into small pieces (about 1-2 cm) using a cutter, etc.

*8: Seaweeds often have other flora and fauna attached on the body and

them.

115

small rock pieces at the base;carefully remove

21.3.3 Filling measurement container with sample(1) In the case of using Marinelli beakers(a) Place an inner bag for Marinelli beaker in a Marinelli beaker without any gaps. (Usedisposablebags to prevent contamination of the wall of the measurement container.)(b) Write or attach the necessary data (e.g., sample identification number) to the Marinelli
beaker, and measure and record the tare weight of the Marinelli beaker, lid and inner bag.
(c) While paying attention to the homogeneity of the sample, place a sample into theMarinelli beaker up to the marked line without gaps. (Photograph 21.9)(d) Lightly press and level the surface of the sample at the marked line. Then, measure theweight of the Marinelli beaker and lid along with the sample, derive the weight of thesample by subtracting the tare weight measured above, and record it.
(e) Seal the inner bag for Marinelli beaker using plastic tape.*9(f) Place the lid on the Marinelli beaker, and seal with plastic tape. (Photograph 21.10)(g) Thoroughly wipe the outer surface of the Marinelli beaker with a paper towel moistenedwith pure water, ethanol, etc.
(h) To prevent contamination of measurement equipment, place the Marinelli beaker in apolyethylene bag, remove air, tie the bag opening to seal it, and present it as a sample
for measurement.

Photograph 21.9
Marinelli beaker filled with a sample(pine needles)

Photograph 21.10
The lid fixed with plastic tape(pineneedles)(2) In the case of using small containers(a) To prevent leakage, wrap thread seal tape around the threaded part of small container.
(b) Write or attach the necessary data (e.g., sample identification number) to a small
container, and measure and record the tare weight of the small container.
(c) While paying attention to the homogeneity of the sample, fill the small container withthe sample without gaps using a laboratory spoon. (Photographs 21.11 and 21.12)(d) Lightly press and level the surface of the sample.
(e) Place a cap on the small container, measure the height of the sample and record it.
(f) Thoroughly wipe the outer surface of the container with a paper towel moistened withpure water, ethanol, etc.
(g) Measure the weight of the small container, derive the weight of the sample by subtracting
the tare weight measured above, and record it.

*9: A rubber band, cable tie, etc. may be used instead.

116

(h) To prevent contamination of measurement equipment, place the small container in apolyethylene bag, remove air, tie the bag opening to seal it (ensure no creases at thebottom of the container), and present it as a sample for measurement.

Photograph 21.11
Small container filled with a sample(pine needles)

Photograph 21.12
Small container filled with a sample(hondawara)

21.4 Storage of samples
21.4.1 Storage for a relatively short period of time(a) Samples prepared using Marinelli beakers: place sample-containing inner bags into
apolyethylene bag or a container.
(b) Samples prepared using small containers: place sample-containing measurement
containersinto a polyethylene bag or a container.
(c) Store measurement samples of inland indicator organisms and pasture plants in arefrigerator, freezer, or cool dark place to prevent decomposition.
(d) Store measurement samples of marine indicator organisms in a freezer.
21.4.2 Long-term storage(a) Dry and ash samples by the methods provided in the Radioactivity Measurement SeriesNo. 13 Pretreatment of Samples for Instrumental Analysis using Germanium Detector,
etc. (Reference 3) and Radioactivity Measurement Series No. 16 Method for Sampling
Environmental Materials (Reference 4). (Prevent contamination of other samples by,for example, washing and cleaning instruments, tools and equipment after use, if theradioactivity concentration of the sample is high.)(b) Place ashed samples in a polyethylene bag or a container, and store in a low-humidity
environment (e.g., inside a desiccator) or by taking measures to prevent contact with air
as much as possible.

117

Explanation

Explanation A Calculation of quantifiable levels
Explanation A.1 Introduction
In this revision, quantifiable levels were calculated anew.
In the previous versions, quantifiable levels were calculated based on germanium
semiconductor detectors with relative efficiency of 15%. However, in recent years, relative
efficiency of commonly-used germanium semiconductor detectors has been improved toaround 30%, and the quantifiable level calculation condition was changed accordingly. Also,in this version, 134Cs was added to nuclides for which quantifiable levels are to be calculated,based on the results of monitoring conducted after the Fukushima Daiichi Nuclear Accident.
Explanation A.2 Calculation method
Spectra used for the calculation of quantifiable levels were obtained from environmental
samples collected after the Fukushima Daiichi Nuclear Accident which were filled into a
Marinelli beaker (2 L) or small container (100 mL: 50 mmφ × 50 mm) and measured using agermanium semiconductor detector with a relative efficiency of around 30%. Setting a spectrumwith appropriate dead time as the reference, detection limits (131I, 137Cs and 134Cs) derived forvarious measuring times and sample groups were specified as the quantifiable levels for themeasuring time and sample group. The detection limits were calculated for various measuring
times and sample groups, following the Radioactivity Measurement Series No. 7 Gamma-ray
Spectrometry using Germanium Detector (Reference 8).
(1) In the case of using 2 L Marinelli beakers in an emergency

Setting a spectrum that was measured using a germanium semiconductor detector with arelative efficiency of around 30% and had the lowest possible dead time as the reference, limitsof detection (131I, 137Cs, 134Cs) derived for various measuring times and sample groups were
specified as the quantifiable levels.
(a) The data obtained by measuring a fallout sample at the Fukushima Prefectural Center for
Environmental Creation was used as the reference spectrum. The relative efficiency ofdetector used in the measurement was 38%, and dead time was 54%. The measurement
conditions are:weight of measured sample (w1), density (ρ), peak efficiency (ε1), measuring time (t1),detection limits (DL1).
(b) Quantifiable levels were calculated for various measuring time.
DLi = DL1/√(ti/t1)
Measuring time (ti): 10 minutes, 30 minutes, 1 hour, 10 hours(c) For a selected sample group, the weight of measured sample (wj) filled into a 2 L
Marinelli beaker was calculated from the density (ρj).
For
the selected sample group, the peak efficiency (εj) when filled into a 2 L Marinelli(d)beaker was calculated using on the software with changing the parameters, density (ρj)
and weight of measured sample (wj). The measurement conditions are:weight of measured sample (wj), density (ρj), peak efficiency (εj), measuring time (ti),detection limit (DLj).
(e) The quantifiable level was calculated for the selected sample group.
DLj = DLi/{(wj/w1) × (εj/ε1)}121

Samples were divided into 5 groups, "Fallout and precipitation", "Drinking water and cow’smilk", "Soil", "Vegetables" and "Meats, eggs, and seafood", referring to OIL6 in the Nuclear
Emergency Guidelines and other relevant information.
(2) In the case of using small containers in an emergency(a) The data obtained by measuring a soil sample at the Japan Chemical Analysis Center wasused as the reference spectrum. The relative efficiency of detector used in themeasurement was 31%, and dead time was 10%. The measurement conditions are:weight of measured sample (w1), density (ρ), peak efficiency (ε1), measuring time (t1),detection limit (DL1).
(b) The weight of measured sample (w2) filled into a small container to a height of 5 cm wascalculated from the density.
(c) The peak efficiency (ε2) when filled into a small container to a height of 5 cm wascalculated using the software with changing the parameters, sample height and weightof measured sample (w2). The measurement conditions are:weight of measured sample (w2), density (ρ), peak efficiency (ε2).
(d) Quantifiable levels were calculated by: DL2 = DL1/{(w2/w1) × (ε2/ε1)}(e) Quantifiable levels were calculated for various measuring time.
DLi = DL2/√(ti/t1)
Measuring time (ti): 10 minutes, 30 minutes, 1 hour, 10 hours(f) For a selected sample group, the weight of measured sample (wj) when filled into a small
container to a height of 5 cm was calculated from the density (ρj). In addition, the peakefficiency (εj) was calculated using the software, and the parameters, material and density(including weight of measured sample), were changed. The conditions are:weight of measured sample (wj), density (ρj), peak efficiency (εj), measuring time (ti),detection limit (DLj).
(g) The quantifiable level was calculated for the selected sample group.
DLj = DLi/{(wj/w2) × (εj/ε2)}
Samples were classified into 6 groups, "Atmosphere", "Fallout and precipitation","Drinking water and cow’s milk", "Soil", "Vegetables" and "Meats, eggs, and seafood",
referring to OIL6 in the Nuclear Emergency Guidelines and other relevant information.
For atmospheric samples, setting a spectrum of active carbon cartridge (sample volume:140.044 m3) that was measured using a germanium semiconductor detector with a relative
efficiency of 27% and dead time of 3.3% as the reference, detection limits were calculated using
the following formula through the software analysis assuming small containers filled with filters(sample volume: 1 m3):
[Filter DL] = [Active carbon DL] / {(1/140.044) × ([Peak efficiency of filter]/[Peak efficiencyof active carbon])}From this formula, detection limits were calculated for selected sample volumes (1 m3, 10 m3,
and 1000 m3) and measuring time (10 minutes, 30 minutes, 1 hour, and 10 hours).

122

Explanation A.3 Calculation results
Tables 2.2 and 2.3 in Chapter 2 show the calculation results of quantifiable levels in the casesof using a Marinelli beaker (2 L) and small container. The calculation results are shown in one
or two effective digits. For 134Cs, calculation was conducted for 605 and 796 keV, and higher
calculation results out of two peaks were adopted.*1
In the case of using a Marinelli beaker (2 L), the calculation results of quantifiable levels
shown in this version were higher than the values shown in the previous version. In thecalculation in this version, the measured spectrum of fallout sample was set as the reference
and the measurement had dead time of 54%, indicating that the sample had many nuclides. Thismay have caused an increase in the background of nuclides to be measured, affected by factors
including Compton scattering, resulting in higher quantifiable levels.
In the case of using a small container, for an atmosphere sample, in both 131I and 137Cs, thecalculation results of quantifiable levels shown in this version were lower than those shown in
the previous version, for all measuring time from 10 minutes to 10 hours. This was caused by
the difference in the relative efficiency of germanium semiconductor detectors, which
previously was 15% while it is 27% for the calculation conducted in this version, and the higher
relative efficiency resulted in lower quantifiable levels. For samples other than the atmosphere,
the calculation results of quantifiable levels shown in this version were equivalent to or higher
than those shown in the previous version for all samples and measuring time. This was likely
caused by the difference in the spectra used for calculation. In the calculation in this version,a measured spectrum of soil samplewas adopted. The measurement of the spectrum had deadtime of 10%, indicating that the sample had many nuclides. Similar to the case of using a
Marinelli beaker, it was likely caused by factors such as Compton scattering.
Explanation A.4 Matters to be noted
The calculation results of quantifiable levels in this version were derived by adopting andapplying the spectra of environmental samples (atmosphere, fallout, and soil) collected after the
Fukushima Daiichi Nuclear Accident to other samples. Additionally, the state of the sample
may vary depending on the situation of contamination, etc. in emergencies. Therefore, theresults shown here shall be regarded as a guide.*1 An analysis institution will be required toswiftly measure a large number of samples in an emergency. To be prepared to handle such asituation and operate measurement equipment efficiently, the institution needs to evaluate andsummarize the relations between sample conditions, measuring time, and quantifiable levels innormal times. One also needs to be aware that actual measurement involves counting statisticsbased uncertainty (counting error), and it is impractical to simply compare them with reference
values. For that reason, if reference values have been specified for various purposes of
emergency survey, analysis institutions are advised to check the reference values for eachmeasurement of samples. Further, the calculation results of quantifiable levels do not take into
account the time elapsed from sampling to measurement, and therefore they may be higher than
the actual quantifiable levels if it takes time from sampling to measurement, due to decay ofradioactive materials. Especially, attention needs to be paid to 131I since its physical half-life isshorter than 134Cs and 137Cs.

*1: This method was adopted because, for 134Cs, different analysis institutions use different peaks inanalysis.
*1: In normal times, quantifiable levels (limits of detection) are usually calculated based on a backgroundspectrum that does notcontain artificial radionuclides.

123Explanation A.5 Reference spectra used for calculation
The reference spectrum charts used for calculating quantifiable levels are shown below.
(FiguresA.1 to A.3)
In these spectrum charts, 1 keV is converted to 2 channels, and the main peaks of 131I,
134
Cs, and 137Cs are indicated.

Cs-134

Cs-134

Cs-134

Cs-134

Cs-134

Cs-137

Cs-134

Count/Channel

Cs-134
Cs-134
Cs-134(1) 2 L Marinelli beaker

ChannelFigure A.1 Gamma-ray spectrum of fallout sample(Sampling location: Fukushima Prefectural Center for Environmental Creation(Fukushima City, Fukushima Prefecture))124

Cs-134

Cs-134

Cs-134

Cs-134

Cs-134

Cs-134
I-131
Cs-134
Cs-137

I-131
Cs-134

I-131

Count/Channel

I-131(2) Small container

ChannelCs-134

Cs-134

Cs-134I- 131
Cs-137

Cs-134

I-131

I-131

Count/Channel

I-131

Figure A.2 Gamma-ray spectrum of soil sample(Sampling location: Japan Chemical Analysis Center(Chiba City, Chiba Prefecture))

ChannelFigure A.3 Gamma-ray spectrum of atmosphere sample(Sampling location: Japan Chemical Analysis Center(Chiba City, Chiba Prefecture))

125

Explanation B Results of study on adsorption of radionuclides on measurement container wall
Explanation B.1 Purpose of study
The previous version of this document prescribed to add sodium chloride as a pretreatment
method for fallout, precipitation, drinking water, and source water, in order to prevent
adsorption of radionuclides on the wall of measurement containers such as Marinelli beakers.
Taking the opportunity of this revision, for the fact that sodium chloride was added in a limited
number of actual emergency cases and no data demonstrate its effect in preventing adsorptionof radionuclides, a study was conducted to compare the state of adsorption of radionuclides
with and without sodium chloride. In addition, based on the descriptions in the Manual for
Measuring Radioactivity of Tap Water, etc., Ministry of Health, Labour and Welfare (2011)(Reference 17) and the U.S. Multi-Agency Radiological Laboratory Analytical Protocols
Manual (MARLAP)*11 , an investigative experiment was conducted with the method below on
the possibility of using sodium thiosulfate for radioactive iodine and nitric acid for radioactive
cesium in place of sodium chloride.
Explanation B.2 Study method(1) Target nuclides
Iodine-131, cesium-137(2) Type of container
2 L Marinelli beaker (with polyvinyl chloride (PVC) inner bag)(3) Method(a) Four 2 L Marinelli beakers were placed on a laboratory bench, 2 L of tap water waspoured into each, and the respective weight was measured.
(b) To three out of the four 2 L Marinelli beakers, 3 g of sodium chloride, 100 mg of sodium
thiosulfate, or 1 mL of nitric acid (13 mol/L) per 1 L of sample was added. One beaker
was left without adding anything as a contrast.
(c) An appropriate amount of an aqueous solution with known radioactivity concentrationsof iodine-131 and cesium-137 was added to each of the 2 L Marinelli beakers. (Iodine131: 11 Bq/L, cesium-137: 4.2 Bq/L)(d) Measurement was performed for each 2 L Marinelli beakers using a germanium
semiconductor detector at a specified measurement time, considering the time required
for radionuclides to be adsorbed on containers and the decay of iodine-131 (half-life:
8.021 days). (Measurement time: 0, 1, 2, 5, 10, and 15 days after preparation)(e) The effect of presence of additives was investigated by checking the transition inradioactivity concentration, assuming that geometric conditions between the detector andradiation source vary due to accumulation of radionuclides on the wall surface if theradionuclides adsorb on the wall of measurement container.
(f) After 15 days after preparation, the content was taken out of the Marinelli beakers, andthe inner bags of Marinelli beaker were washed using deionized water. The washed innerbags were measured to check whether the target nuclides present on the surface of theinner bags.
(g) The inside of the inner bags was washed with a nitric acid solution (6.5 mol/L) to desorb
radionuclides adsorbed on the surface of the inner bags. The washed inner bags wereplaced in small containers (U-8 containers) and measured using a germanium
semiconductor detector to investigate the difference in the state of adsorption on*1:

Multi-Agency Radiological Laboratory Analytical Protocols Manual, NUREG-1576, EPA402-B-04-001B, NTIS
PB2004-105421 (2004) (Reference20)

126container depending on the additive.
Explanation B.3 Study results
Figure B.1 shows the transition in iodine-131 concentration for different additive. For the
samples to which sodium chloride, nitric acid, or no additive was added, the measured iodine131 concentrations transitioned slightly higher than the added radioactivity concentration (11Bq/L). For the sample to which sodium thiosulfate was added, the measured iodine-131
concentrations were almost the same as the added radioactivity concentration, showing a trend
different from the results for other samples. To confirm this trend for the sample to which
sodium thiosulfate was added, another sample with additional sodium thiosulfate was preparedand measured in the same manner (measurement time: 0, 1, 4, 7, 12, and 15 days after
preparation), and the results showed the same trend of exhibiting almost the same iodine-131
concentrations as the added radioactivity concentration. Figure B.2 shows the transition in
iodine-131 concentration for different additives, expressed in the ratios to the measurement
result on day 0. In all samples, the ratios transitioned within ±5%.

Iodine-131 concentration (Bq/L) NaCl  Sodium thiosulfate  Nitric acid  No additive  Sodium thiosulfate (retest)

Number of days elapsed

Figure B.1 Transition in iodine-131 concentration for different additives*2(Iodine-131 addition amount: 11 Bq/L; the error bars show counting errors)*2: The measurement for sodium thiosulfate (retest) was performed after the measurements for other samples, and counting

errors are larger than other samples due to decay.

127

Iodine-131 concentration (ratio to day 0)

 NaCl  Sodium thiosulfate  Nitric acid  No additive  Sodium thiosulfate (retest)

Number of days elapsed

Figure B.2 Transition in iodine-131 concentration for different additives *3(Normalized to the concentration on day 0)
Figure B.3 shows the transition in cesium-137 concentration for different additives. In all
samples, the measured concentrations transitioned within ±5% of the added cesium-137
radioactivity concentration (4.2 Bq/L). Figure B.4 shows the transition in cesium-137
concentration for different additives, expressed in the ratios to the measurement result on day
0. In all samples, the ratios transitioned within ±5%.

*3: The measurement for sodium thiosulfate (retest) was performed after the measurements for othersamples, and counting

errors are larger than other samples due to decay.

128

Cesium-137 concentration (Bq/L) NaCl  Sodium thiosulfate  Nitric acid  No additive  Sodium thiosulfate (retest)

Number of days elapsed

Figure B.3 Transition in cesium-137 concentration for different additives(Cesium-137 addition amount: 4.2 Bq/L; the error bars show counting errors) No additive  Sodium thiosulfate (retest)

Cesium-137 concentration (ratio to day 0)

 NaCl  Sodium thiosulfate  Nitric acid

Number of days elapsed

Figure B.4 Transition in cesium-137 concentration for different additives(Normalized to the concentration on day 0)

129

Figures B.5 and B.6 show the spectra of PVC inner bags washed by ion-exchange water whichwere measured using a germanium semiconductor detector. When sodium chloride was added,
as shown in Figure B.5, iodine-131 was detected while cesium-137 was not detected, indicatingthat iodine-131 adsorbed on the inner bag. Similar results were obtained for the samples withnitric acid added and no additives. Meanwhile, when sodium thiosulfate was added, as shownin Figure B.6, both iodine-131 and cesium-137 were not detected, indicating no adsorption on
the inner bag. Table B.1 summarizes the difference in the state of adsorption depending on the
additive. In this table, the ratio of adsorption on PVC inner bag shown in parentheses wasestimated by the computational simulation for the state of adsorption described in Explanation
B.5. When sodium chloride was not added, about 50% of iodine-131 was considered to havebeen adsorbed on the inner bag, indicating that addition of sodium thiosulfate is effective inpreventing adsorption of iodine-131.
Additionally, when the iodine-131 adsorbing PVC inner bags in Marinelli beaker were
washed with a nitric acid solution, iodine-131 and cesium-137 were not detected from the washsolution. Further, iodine-131 was detected when measurement was performed for the acidwashed inner bags, indicating that iodine-131 was strongly adsorbed in the PVC inner bags.
Based on these results, using tap water with sodium thiosulfate added to which certain
amounts of iodine-131 and cesium-137 were added, an additional experiment was performed
on a Marinelli beaker and U-8 container with polyethylene inner bags, to investigate adsorptionof radionuclides. When the containers were measured using a germanium semiconductor
detector 5 days after placing the sample solution, the measurement results were almost the sameas the addition amount for both containers. Additionally, when the content was taken out of thecontainers, and the polyethylene innerbags and small container were washed with ion-exchangewater and measured using a germanium semiconductor detector, iodine-131 and cesium-137
were not detected. These results also demonstrated that addition of sodium thiosulfate iseffective in preventing adsorption of iodine-131.
Iodine-131: detected

Cesium-137: not detected

Figure B.5 Measured spectrum of inner bag for Marinelli beaker(sample to which sodium chloride was added)

130

Iodine-131: not detected

Cesium-137: not detected

Figure B.6 Measured spectrum of inner bag for
Marinelli beaker(sample to which sodium
thiosulfate was added)
Table B.1 Difference in the state of adsorption depending on additive
Additive

Sodium chloride

Sodium thiosulfate

Nitric acid

None

Iodine-131

Adsorbed(49%)*1

No adsorption

Adsorbed(52%)*1

Adsorbed(53%)*1

Cesium-137

No adsorption

No adsorption

No adsorption

No adsorption*1 Values in parentheses are ratios of absorption on PVC inner bag estimated fromthe results of computational simulation for the state of adsorption described in
Explanation B.5.

Explanation B.4 Evaluation of peak counting efficiency by computational simulation(1) Conditions of computational simulation
Peak counting efficiency of germanium semiconductor detectors was evaluated throughcomputational simulation for two cases; when iodine-131 and cesium-137 are evenly distributed
in a water sample (2 L Marinelli beaker, U-8 container), and when iodine-131 and cesium-137
are adsorbed onto container or inner bag. Figure B.7 shows the geometry of computational
simulation. Computational simulation has been conducted and relevant diagrams were provided
through the courtesy of Mr. Jun Saegusa of Japan Atomic Energy Agency.

131

･ Code used: MCNP-6.1･ Detector, sample (radiation source), etc. are 3-dimensionally simulated,and peakcounting efficiency is compared
Relative efficiency 40% n-type Ge 2 L Marinelli beaker
Radiation source(shown in red)

Shield

Water

Water

Acrylic
protection cap(A) Radiation source isevenlydistributed ina water sample

Water

Detector(C) Radiation source iscompletely adhered
throughout an inner
bag Distributed 0.051.05 mm fromcontainer wall and at
the top part ofbag witha thickness of 1 mm

(B) Radiation source iscompletely
adhered to the sideand bottom wallof inner bag Distributed
0.05-1.05 mm fromcontainerwall

Figure B.7 Setup of computational simulation(2) Results of computational simulation
Table B.2 summarizes the results of computational simulation conducted under the conditions
shown in (1). Calculation was conducted for two types of Marinelli beaker inner bag materials:
polyvinyl chloride (PVC) and polyethylene (PE). Compared with Setup (A) where the radiation
source was evenly distributed in a water sample, in Setup (B) where the radiation source wascompletely adhered throughout an inner bag, peak counting efficiency of iodine-131 andcesium-137 was higher by approximately 7% and 6%, respectively. In addition, compared with
Setup (A), in Setup (C) where the radiation source was completely adhered to the side andbottom wall of inner bag, peak counting efficiency of iodine-131 and cesium-137 was higher
by approximately 21% and 19%, respectively. No significant difference in peak counting
efficiency was observed between the inner bag materials, as shown in Table B.2.
Table B.3 summarizes the results of computational simulation conducted under similarradiation source distribution conditions using a p-type germanium semiconductor detector(relatie efficiency: 25%) that was used in the a forementioned investigative experiment. The
inner bag material selected was polyvinyl chloride that was mainly used in the investigative
experiment. Compared with Setup (A), in Setup (B), peak counting efficiency of iodine-131
and cesium-137 was higher by 3.1% and 0.38%, respectively. In addition, compared with Setup(A), in Setup (C), peak counting efficiency of iodine-131 and cesium-137 was higher by 17%
and 12%, respectively.

132

Table B.2 Results of simulation of peak counting efficiency for each setup (In the case of
relative efficiency 40% n-type Ge and 2 L Marinelli beaker)
Nuclide(Energy)

Evenlydistributed in water(A)

All adhered toinner bag(including top part)(B)

All adhered toinner bag(excluding top part)(C)

Table B.3 Results of simulation of peak counting efficiency for each setup (In the case of thesame conditions as investigative experiment, relative efficiency 25% p-type Ge and 2
L Marinelli beaker)
Nuclide(Energy)

Evenlydistributed inwater (A)

Adhered toinner bag(including top part)(B)

Adhered toinner bag(excluding top part)(C)

Values in parentheses are the actual measurement values obtained in theinvestigative experiment.
Also, computational simulation of peak counting efficiency was conducted for U-8
containers, for Setup (A) where the radiation source is evenly distributed in a water sample
and Setup (C) where the radiation source is completely adhered to the wall and bottom ofcontainer. Figure B.8 shows the setup of computational simulation, and Table B.4 summarizes
the results of computational simulation. Compared with Setup (A), in Setup (C), peakcounting efficiency of iodine-131 and cesium-137 was higher by 23% and 24%, respectively.
Relative efficiency 40% n-type Ge, U-8 container
Water

Water

(C) Radiation
source iscompletely
adhered to the walland bottom ofcontainer(A) Radiation
source is evenly
distributed in awater sample

Figure B.8 Geometry of computational simulation
133

Table B.4 Results of simulation of peak counting efficiency for each setup(In the case of relative efficiency 40% n-type Ge and U-8 container container)
Nuclide(Energy)

Evenlydistributed in water(A)

Adhered to walland bottom ofcontainer (C)(3) Summary of computational simulation results
Peak counting efficiency, 𝑦 , with a ratio of transition of radiation source to Marinelli
beaker innerbag (deposition rate), 𝑝 , is expressed by the following formula:𝑦 = (1 − 𝑝) 𝑎 + 𝑝 × 𝑏,
where 𝑎 and 𝑏 are peak counting efficiency in the case of radiation source being evenly
distributed in a water sample and in the case of radiation source being fully deposited onto an
inner bag, respectively. Figure B.9 shows this equation plotted with applying the results ofcomputational simulation for Setup (A) and Setup (C) in Table B.3 that correspond to the same
conditions as the a forementioned investigative experiment. Figure B.9 indicates that, underthese conditions, iodine-131 concentration is overestimated by 8.5% when deposition ratio toinner bag is 50% (p = 0.5) and by approximately 17% when radiation source is fully deposited
to an inner bag (p = 1). Note that separate evaluation is required for other sample shapes, special
detector, or different deposit distribution.

Radioactivity isoverestimated(evaluated to safe side)

Figure B.9 Chart between transition ratio, p, and efficiency increase ratio(Relative efficiency 25% p-type Ge, 2 L Marinelli beaker, excluding the top part of inner bag)134

Explanation B.5 Summary of study results
The state of adsorption was investigated for iodine-131 and cesium-137 using polyvinyl
chloride inner bag in 2 L Marinelli beaker. As additional experiment, the state of adsorption
was investigated for polyethylene inner bag and polypropylene small container (U-8 container).
Regarding iodine-131, when sodium thiosulfate was used as an additive, the experimental
results indicated no adsorption on polyvinyl chloride. When sodium chloride, nitric acid, or no
additive was added, on the other hand, the experimental results indicated adsorption on
polyvinyl chloride inner bag. As for cesium-137, regardless of the type of additive, theexperimental results indicated no adsorption into polyvinyl chloride inner bag, polyethylene
inner bag, or polypropylene small container. From the results of computational simulation on
the state of adsorption, it was estimated that approximately 50% of iodine-131 adsorbed inpolyvinyl chloride inner bag when sodium thiosulfate was not added, indicating that additionof sodium thiosulfate is effective in preventing adsorption of iodine-131.
Based on these findings, for fallout and precipitation samples in Chapter 5 and drinking waterand inland water samples in Chapter 6, it was decided to add sodium thiosulfate in order toprevent adsorption of iodine-131 into the wall of measurement containers. The addition amountis to be the same as those prescribed in the Manual for Measuring Radioactivity of Tap Water,etc. (Reference 17). The timing of addition is to be when filling a sample into a measurement
container, similar to the current pretreatment method. If sodium thiosulfate-added samples areto be stored for a relatively short period of time, they are to be stored in a state of being placedin measurement containers. Since sodium thiosulfate has already been added, no new additive
is to be added. If sodium thiosulfate-added samples are to be stored for a long period of time,acid is to be added to them to prevent adsorption of radioactive cesium. The method of addition
shall conform to the methods provided in the Radioactivity Measurement Series No. 13
Pretreatment of Samples for Instrumental Analysis using Germanium Detector, etc. (Reference3) and Radioactivity Measurement Series No. 16 Method for Sampling Environmental
Materials (Reference 4). For seawater and cow’s milk samples, the Radioactivity Measurement
Series No. 16 Method for Sampling Environmental Materials (Reference 4) shall be followed.

135

Appendix

Appendix 1 Equipment, tools, reagents, etc. to be made available and ready for use at all times
Name of equipment, tool, reagent

Description

To be used for checking radiation levels of samples on
acceptanceor carry-in, before starting preparation ofsamples for measurement, for the purpose of
Scintillation survey meter for gamma- preventing
rays
cross-contamination of samples, preventing exposureof workers, and determining sample volume. Whether
they are functioning properly shall be periodicallychecked in accordance with the user’s manual.
Plastic cylindrical measurement container, whichenables sealing in a relatively large quantity of sample.
Radioactivity Measurement Series No. 7 GammaMarinelli beaker
ray Spectrometry using Germanium Detector(Reference 8) provides details about 2 L and 700
mL Marinelli beakers.Recently, 1 L Marinelli
beakers have also become commercially available.
Polyethylene or polyvinyl chloride bag that is used toseal a sample inside to prevent contamination of the
Inner bag for Marinelli beaker
inner wall of Marinelli beaker. Samples may be stored
sealed in inner bags after measurement.
Cylindrical measurement container, usually with acapacity ofabout 100 mL. Polypropylene or polystyrene
products called U-8 containers are widely used.
Small container
Radioactivity Measurement Series No. 7 Gamma-ray
Spectrometry using Germanium Detector (Reference8)provides details about several types of small
containers.
To be used to cover measurement containers to prevent
contamination of measurement equipment. They are also
Polyethylene bag
used for many other purposes. Several types ofpolyethylene bags shall be made available to suit thegiven situation and purposeof use.
To be used for cutting vegetables, fruit, tea leaves, peas
and beans, seaweeds, meats, dairy products, seafood,Cutter, scissors, kitchen knife, etc.
etc. into small pieces.
The right tool shall be selected depending on thesize and shape of the sample.
To be used for filling sample into measurement
Laboratory spoon
container and treatment of soil samples.
Those with a length of around 20 cm are suitable.
To be used for portioning, volume adjustment,
etc. of liquid samples.
Piston pipette
It is preferable to have products with a volume of 1-10
mL to be used according to the purpose.

139

Gloves (rubber or polyethylene)

Paper towel

Worn to prevent cross-contamination of samples andexposureof workers.
Disposable general-purpose gloves are often used.
Disposable product commonly used in chemical
experiment for the purpose of decontamination andprevention of spreading of contamination.
To be used for mixing eggs.

Container (e.g., beaker, mixing bowl)

Refrigerator, freezer

Graduated cylinder

Ethanol

Sodium thiosulfate

Hydrochloric acid or nitric acid

To be used for storing samples that are prone todecomposition. Samples are stored either in arefrigerator or freezer depending on the nature of thesample.
To be used for measuring the volume of sample. They
may also be used for checking the capacity ofMarinelli beakers.
To be used to decontaminate measurement containers,
etc. by wiping them with paper towels moistened withethanol. Applying ethanol to acrylic equipment or tool
may cause it to crack due to swelling.
Added to fallout, precipitation, drinking water, andinland water samples for the purpose of preventing
radioactive iodine from adsorbing on measurement
container.
Added to fallout, precipitation, drinking water, inland
water, and seawater samples for the purpose of
preventing nuclides from adsorbing on measurement
container, when the sample is to be stored for a long
period of time.

140

Appendix 2 Marinelli beaker and inner bag for Marinelli beaker
Photograph 2.1 and Figure 2.1 show a Marinelli beaker. Photographs 2.2 and 2.3 show an
inner bag for Marinelli beaker.
In the method provided in this document, in principle, samples are to be sealed in apolyethylene inner bag for Marinelli beaker to be presented for measurement. As shown in
Photographs 2.4 to 2.6, an inner bag for Marinelli beaker shall fit perfectly into the Marinelli
beaker without any gaps. Inner bags shall also be adequately strong not to cause spreading ofcontamination due to breaking, etc.

2000 ml water level marking

Photograph 2.1
2 L Marinelli beaker

Figure 2.1
2 L Marinelli beaker

Photograph 2.2
Inner bag for 2 L Marinelli beaker

Photograph 2.3
Inner bag for 2 L Marinelli beaker inserted
in 2L Marinelli beaker141

Photograph 2.4
Polyethylene inner bag for Marinelli beakerwith a sample inside(strawberry)

Photograph 2.6
2 L Marinelli beaker filledwith a sample(strawberry)

Photograph 2.5
Filling an inner bag-installed Marinelli
beaker with a sample(strawberry)142

Appendix 3 Small container

2.5

61

Photograph 3.1 and Figure 3.1 show small containers.
Photographs 3.2 and 3.3 show a small container filled with a sample.

50

Photograph 3.1
Small container (U-8)

Figure 3.1
Small container

Photograph 3.3
Small container filled with asample(strawberry)

Photograph 3.2
Filling a small container with asample(strawberry)

143

Information

Information 1 Concept of implementation items and content of emergency monitoring
The basic concept of implementation items and content of emergency monitoring is provided
in the Nuclear Emergency Preparedness and Response Guidelines, NRA (2018) (Reference 1)
and “Emergency Monitoring” (supplementary reference material of the Nuclear Emergency
Preparedness and Response Guidelines), Radiation Monitoring Division, Radiation Protection
Department, NRA (2017) (Reference 2). Analysis and measurement of environmental
samples are conducted based on the concept.
Information 1.1 Chart with food and drink intake restrictions
Concentration of radionuclides in food and drinks is to be measured and analyzed within about
1 week of occurrence of a nuclear emergency, and intake restrictions are to be swiftly
implemented if the concentration exceeds OIL6, the operational intervention level of food anddrink intake restrictions.*1
Analysis and measurement conditions such as analysis sample volume, sample pretreatment
method, and measuring time need to be determined, taking into account the OIL6 andquantifiable levels*2. Tables 1.1 and 1.2 show a comparison between quantifiable levels andOIL6. Values shown in the tables are calculated based on the spectra presented in Explanation
A. Note that quantifiable levels are summed up for 134Cs and 137Cs because OIL6 for radioactive
cesium is applied as a sum of 134Cs and 137Cs.
Table 1.1 Comparison between quantifiable levels and OIL6 (drinking water, cow’s milk)
Name ofsample134

Measurement
container

Marinelli beaker(2 L)
Drinking
water
Cow’smilk
Small containerCs + 137Cs quantifiablelevel(sum)131

I quantifiable level

10 min30 min1h

10 h

10 min30 min

1h

10 h

110

70

50

20

190

120

90

40

Unit

Bq/kg
350

200

OIL6 value

150

50

300

590

350

250

200

80

Bq/kg

Shaded cell: Quantifiable level exceeding OIL6 value
Table 1.1 indicates that, when drinking water or cow’s milk is measured using Marinelli
beakers (2 L) as measurement containers for determining the necessity of implementing intake
restrictions, a measuring time of 10 minutes is enough for both radioactive iodine andradioactive cesium. Meanwhile, if small containers are used as measurement containers, ameasuring time of 30 minutes and about 10 hours is required for radioactive iodine andradioactive cesium, respectively.
From the above, for liquid samples such as drinking water and cow’s milk, because they do
not require any specific pretreatment (e.g., cutting into small pieces), if sample volume issufficiently available, it is anticipated that using Marinelli beakers allows measuring a large
number of samples in a short period of time, compared with biological samples such as
vegetables.
*1: See Table 2.1 in Chapter 2.
*2: See Tables 2.2 and 2.3 in Chapter 2.

147

Table 1.2 Comparison between quantifiable levels and OIL6 (vegetables, seafood, etc.)
134

10 min30 min1h

10 h

Cs + 137Cs quantifiable level(sum)
10 min30 min
1h
10 h

200

120

80

30

350

210

150

60

Bq/kg

610

350

250

80

1050

610

440

140

Bq/kg

120

70

50

20

210

120

90

40

Bq/kg

360

210

150

50

610

350

250

80

Bq/kg

131

I quantifiable level

Name ofsampleVegetables

Measurement
container
Marinellibeaker(2 L)
Smallcontainer

Meats
Eggs
Seafood

Marinellibeaker(2 L)
Smallcontainer

OIL6 value

2,000

500

Unit

Bq/kg

Shaded cell: Quantifiable level exceeding OIL6 value
Table 1.2 indicates that, when biological samples such as vegetables, meats and seafood aremeasured using Marinelli beakers (2 L) as measurement containers for determining thenecessity of implementing intake restrictions, a measuring time of 10 minutes is enough forboth radioactive iodine and radioactive cesium. Meanwhile, if small containers are used asmeasurement containers, a measuring time of 10 minutes is required for radioactive iodine, andfor radioactive cesium, a measuring time of about 1 hour is required for vegetables and about
30 minutes for meats, seafood, etc.
These samples require pretreatment (e.g., cutting into small pieces), and pretreatment to fill a
Marinelli beaker (2 L) is more time consuming than filling a small container. Therefore,
considering the time required for pretreatment and measurement, this table suggests thatanalysis and measurement would be more efficient when small containers are used asmeasurement containers.

148

Information 1.2 Chart with evaluation of internal exposure doses
Evaluation of internal exposure doses in emergency monitoring is mentioned in the“Emergency Monitoring” (supplementary reference material of the Nuclear Emergency
Preparedness and Response Guidelines), Radiation Monitoring Division, Radiation Protection
Department, NRA (2017) (Reference 2). Reference 2 states that concentration of radioactive
materials in environmental samples needs to be determined as part of monitoring forproviding information to evaluate the effects of radiation on local residents and theenvironment. In so doing, according to Reference 2, it is important to measure theconcentration of nuclides such as 134Cs and 137Cs, based on the lesson learned from the
Fukushima Daiichi Nuclear Accident, in addition to the nuclides whose radiation doses inpublic are to be evaluated in case of an accident under safety review of nuclear facilities.
Evaluation of internal exposure doses is also discussed in the “Normal Time Monitoring”(supplementary reference material of the Nuclear Emergency Preparedness and Response
Guidelines), Radiation Monitoring Division, Radiation Protection Department, NRA (2018)(Reference 9), which outlines views about evaluation methods of committed effective dose due
to internal exposure. Although data of radioactive material concentration analysis used inemergency monitoring is handled differently from data for normal time monitoring, themethods provided in Reference 9 may be applicable as methods of dose evaluation in
emergency monitoring.
The necessary levels of radioactive material concentration analysis vary depending on the
purpose of evaluation of internal exposure doses. However, in some emergency cases, analysis
and measuring methods similar to those used in normal time monitoring may have to be adopted.
Information 1.3 Chart with environmental impact survey in emergency
When a nuclear emergency arises, relevant authorities are likely to conduct environmental
impact surveys for the purpose of evaluating and ascertaining its overall impact on thesurrounding environment. In such cases, methods conforming to the implementation content of
normal time monitoring may be adopted depending on the conditions and the state of recovery
from the nuclear emergency. Analysis institutions have to be aware that samples with
unexpectedly high radioactivity concentration may be provided in such occasions, and need totake measures against cross-contamination of samples and contamination of laboratories before
starting analysis and measurement.

149

Information 2 Handling high-concentration samples
Definitive data on radioactivity concentration of sample are not always available prior to
analysis ormeasurement. However, in some cases, radioactivity concentration of environmental
samples can be estimated from the condition of accident, data of ambient radiation dose rates
in the surroundings, and/or measurement values obtained using radiation measurement
equipment such as survey meters. The sections below discuss matters to be noted at the time ofcollection and measurement of samples whose radioactivity concentration is expected to behigh.*1
Information 2.1 Matters to be noted in sample collection
When collecting environmental samples for emergency monitoring, in some cases, portableradiation measurement equipment such as a survey meter is used to measure ambient radiationdose rates around the sampling locations. If the measurement values are higher than normal
measurement values, it is highly possible that the surrounding of the sampling location iscontaminated with radioactive materials. When collecting environmental samples in suchplaces, workers need to employ all necessary measures against exposure and contamination,
including use of disposable rubber gloves and protective clothing. In addition, they shallconsider taking measures to prevent internal exposure, as necessary, such as use of masks.
The collected samples shall be handled assuming that they are contaminated with radioactive
materials, regardless of the measurement values obtained using the portable radiation
measurement equipment. Additional contamination prevention measures to be taken for such
samples include placing the collected samples in polyethylene bags, sealing the bags, andthen further placing the bags in another polyethylene bag. If soil or other materials haveattached to work wear or shoes, they shall be brushed off to prevent them (sources ofcontamination) from being taken into analysis sites or laboratories. If any sampling tools arereused, to prevent cross-contamination of samples, they shall be cleaned using water or
moistened paper towels prepared in advance before moving to the next sampling location.
Information 2.2 Matters to be noted in sample measurement
Gamma-ray spectrometry in emergencies sometimes necessitates measurement of highconcentration samples, resulting in a high-count-rate measurement. When this is the case, thenumber of incident gamma rays becomes significantly large, and electronic devices used forprocessing the signals will become overloaded.
A high-count-rate measurement is associated with the following problems: Increased dead time Pulse pile-up Random summing
Pulse pile-up and random summing cause the net count rate of gamma-ray peaks to decline
and result in underestimation. For details of the problems in measurement that arise associatedwith increased dead time, including increased time required for measurement, refer to theRadioactivity Measurement Series No. 29 Gamma-ray Spectral Analysis Using Germanium
Detector in Emergencies (Reference 15).

*1

: For matters to be noted in the sample acceptance stage, sample preparation, and measurement container
filling, refer to 2.3 in Chapter 2.
150

If the dead time is found to be long with starting the sample measurement (approximately 10%
as a guide), it is necessary to implement appropriate measures such as reducing the sample
volume to reduce the number of gamma rays emitted from the sample. When reducing thesample volume, observe the following points are to be noted:*2· If measurement was performed using Marinelli beakers, the sample is to be transferred
to small containers to reduce the sample volume.
· If measurement was performed using small containers, the sample volume inside themeasurement containers is to be reduced.
· Regarding the new container to which the sample is to be transferred, efficiency
calibration must be performed using a standard radiation source in the same container.
When transferring samples from Marinelli beakers to small containers or reducing sample
volume inside small containers, pay extra attention to the homogeneity of the sample.

*2: For matters to be noted during preparation, refer to 2.3 in Chapter 2.

151

Information 3 Long-term storage methods of samples
Some environmental samples used for gamma-ray spectrometry in emergencies may bevaluable, requiring long-term storage. Such valuable samples are highly likely to undergo otheranalyses and measurements in addition to gamma-ray spectrometry, which needs to be taken
into account in the long-term storage.
If a sample is prone to decomposition or likely to adsorb on the sample storage container used,
the sample shall be stored after applying a method of pretreatment for gamma-ray spectrometry
or for radiochemical analysis of nuclides such as 90Sr and 239+240Pu that is performed in normal
time monitoring (Table 3.1). The sample pretreatment methods listed in Table 3.1 conform to
the methods provided in the Radioactivity Measurement Series No. 13 Pretreatment of Samples
for Instrumental Analysis using Germanium Detector, etc. (Reference 3) and Radioactivity
Measurement Series No. 16 Method for Sampling Environmental Materials (Reference 4).
Table 3.1 Pretreatment method of samples for long-term storage
No

Sample1

Air

Pretreatment
methodAs is, orashing2

Fallout andprecipitation

3

4

No

Sample10Peas and beans

Adding acid11

Mushrooms

Drinking water andinland water

Adding acid

12

Seaweeds

Seawater

Adding acid

13

Meats

5

Soil

As is, ordrying6

Vegetables

7

Fruit

8

9

14

Cow’s milk

15

Dairy product

16

Eggs

Tea leaves

17

Seafood

Grains18

Indicator organisms(including pastureplants)Ashing(or drying)152

Pretreatment
methodAshing(or drying)When simultaneously ashing multiple samples using an electric furnace, adequate attention
needs to be paid to prevention of cross-contamination of samples. Measures to prevent crosscontamination include ashing samples with similar radioactivity concentrations and ashing ahigh-concentration sample alone, provided that measurement results of gamma-ray
spectrometry in emergency are available. In addition, extra attention needs to be paid whenhandling an ashed sample because the sample has been concentrated and, accordingly, its
radioactivity concentration has been increased. Further, contamination of the electric furnace
shall be prevented.
Pretreated samples are unlikely to decompose compared to untreated samples, but mold may
grow on them if they absorb moisture from the atmosphere. Therefore, pretreated samples shallbe stored in a cool dark place or, if necessary, in a desiccator, to avoid high temperatures andhigh humidity.
If nuclides to be analyzed in the future are known at the time of storing a sample, considerationneeds to be given to storing the sample by a suitable mean for the method of the analysis.

153

Information 4 Matters to be noted when discarding samples*1
Information 4.1 Matters to be noted when discarding samples
Environmental samples collected for emergency monitoring need to be discarded properly incompliance with relevant laws and regulations of the time.
After the Fukushima Daiichi Nuclear Accident, waste contaminated with radioactive materials
is disposed of in accordance with the Act on Special Measures concerning the Handling ofEnvironment Pollution by Radioactive Materials Discharged by the Nuclear Power Station
Accident Associated with the Tohoku District-Off the Pacific Ocean Earthquake That Occurredon March 11, 2011 (hereinafter referred to as “the Act”).
The Act stipulates that waste with radioactivity concentration exceeding a certain level (8,000
Bq/kg) and designated by the Minister of the Environment is to be disposed of as designatedwaste by an appropriate method under the responsibility of the national government.
When discarding environmental samples for emergency monitoring as industrial waste, therelevant organization needs to request a municipality or waste processing business operator
to dispose of them after confirming that radioactivity concentration is not more than the levelstipulated by the Act.
Information 4.2 Method of measurement of radioactivity concentration for contaminated waste
The Ministry of the Environment published a six-part guideline based on the Act, detailing
Ordinances of the Ministry of the Environment and other relevant regulations stipulating thestandards of storage and disposal of waste contaminated with radioactive materials discharged
by the Fukushima Daiichi Nuclear Accident. Of which, Part V: Guidelines for Method of
Measurement of Radioactive Concentration (2nd Edition), Ministry of the Environment (2013)(Reference 21) provides methods of measurement of radioactivity concentration, etc. forcontaminated waste. Among the several types of target samples listed in the Guidelines, thesection below cites the method to measure radioactivity concentration of discharged sludge
since it is similar to soil sample discussed in this document.
· Discharged sludge
Discharged sludge corresponds to soil among the sample types discussed in this document.
The Guidelines provide that specimen sampling shall be conducted considering therepresentativeness of specimen, and all collected samples are to be placed into one container(a plastic bag with a fastener is acceptable) and mixed well. Analysis of radioactivity
concentration is to be conducted through measurement using a germanium semiconductor
detector, NaI (Tl) scintillation spectrometer, or LaBr3 (Ce) scintillation spectrometer. Table
4.1 shows conditions for nuclide analysis by a germanium semiconductor detector, etc.
Table 4.1 Analysis conditions for discharged sludge
Measurement sample

Pretreatment

Sample container

Discharged sludge

None, or crushingU-8 container

Measuring time(reference)
1,000 - 2,000
seconds

Detection limit
10 - 30 Bq/kg*1: Cited from the Ministry of the Environment website about information on disposal of waste contaminated with radioactive

materials (http://shiteihaiki.env.go.jp/)154Information 5 State of cesium present in inland water
According to the results of the survey conducted for river water in the Kanto region andFukushima Prefecture from 2011 to 2012 (Reference 22) , the total 137Cs concentration (sum of
cesium in dissolved and suspended forms; the same shall apply hereinafter) was 0.009-18.7
Bq/L, of which dissolved form accounted for 0.002-1.5 Bq/L and suspended form 0.007-18.2
Bq/L. Depending on the purpose of the monitoring survey*1, dissolved cesium needs to be
separated from suspended cesium.*2 The section below describes typical separation methods
and their characteristics. (Reference 23)
For dissolved matters, pretreatment is to be performed using an appropriate method such as
evaporative concentration, in addition to the method (direct measurement) described in Chapter
6. (Reference 4)
For suspended matters collected on a filter, the filter is to be dried in a drier or desiccator, andpretreated following the method described in Chapter 4.
 Filtration method (pressurized filtration, vacuum filtration)
A method to filtrate water by passing water through a filter. Time required for filtration is
reduced by pressurizing or vacuuming. Suspended matters are collected on a filter. The filter
can be of any pore size and diameter, but usually filters with a pore size of 1 μm or 0.45 μm
are used. (References 17, 23, and 24) This method is applicable either at sampling sites orlaboratories, using general equipment. Filtrate can be used for concentration and analysis of
dissolved matter.
 Multistage filter method
A method to filtrate water by passing water through 2-10 filters with a pore size of 0.45 μm
and diameter of 150 mm (or 142 mm) arranged in parallel. Although it has the term “stage”
in its name, this method passes branched source water through one of the filters once.
Therefore, it allows filtrating a large amount of water (one hundred to several hundreds ofliters, depending on the turbidity) at the same time. Due to its nature, this method is often
used at sampling sites, but can be applied in laboratories as well. Filtrate can be used forconcentration and analysis of dissolved matter.
 Cartridge filter method
A method to filtrate water by passing water through a non-woven cartridge filter with a poresize of 1 μm. Suspended matters are collected in the filter. This method is applicable either
at sampling sites or laboratories. Filtrate can be used for concentration and analysis of
dissolved matter.

*1: Concentration of cesium dissolved in water is important as the basic information for evaluating various matters related toradioactive cesium discharged by the Fukushima Dai-ichi Nuclear Accident, including its transition to crops, long-term
environmental dynamics, and impact on aquatic organisms, and many surveys and studies have been conducted to date.
(Reference 22)*2: Behavior of dissolved matter in the environment is greatly different from that of suspended matter. Dissolved matter iseasily absorbed by crops, while suspended matter is not easily absorbed by plants, in most cases. For that reason,environmental dynamics forecast, etc. requires both concentration of dissolved matters and concentration of suspended
matters, and therefore they need to be separated. (Reference 23)155 Cross-flow filter method
A method to filtrate water by passing water through a cross-flow filter. Suspended matters
are collected as a highly concentrated suspension. This method enables efficiently collecting
suspended matters even if the sample water is a highly concentrated suspension of 100 mg/Lor greater. (The recovery rate is 95% or greater at a water feed rate of 0.3 L/min.) Due to its
nature, this method is often used at sampling sites, but can be applied in laboratories as well.
Filtrate can be used for concentration and analysis of dissolved matter.
 Continuous flow centrifugation
A method to separate and collect suspended matters by passing water through a continuous
flow centrifugation system. The form of suspended matters collected varies depending on
the continuous flow centrifugation system used. This method enables processing a large
amount of water (about 1,000 L - 2,000 L) at the same time, and filtrate can be used forconcentration and analysis of dissolved matter. Due to its nature, this method is mostly usedat sampling sites.
 Suspended sediment sampler method (Reference 25)
A method to collect a large quantity of suspended matters by installing a suspended
sediment sampler in a river for a long period of time (several days to several months). A
suspended sediment sampler can be easily made by capping both ends of a polyvinyl
chloride tube and inserting a holed plastic tube. After collecting a sample, water needs to be
removed from the sample through evaporation or filtration using a glass fiber filter. Thismethod enables collecting a large quantity of suspended matters easily and at low cost, butdoes not necessarily collect all suspended matters that flow into the sampler. Note that thismethod does not allow analysis of dissolved matter, and cannot be used in laboratories due
to its nature.

References
4 放射能測定法シリーズ No.16「環境試料採取法」
17 「水道水等の放射能測定マニュアル」 厚生労働省（2011）22 保高徹生，陸水中における微量溶存態放射性セシウムの濃縮法の比較，分析化学
66 巻 4 号(2017)
23 「環境放射能モニタリングのための水中の放射性セシウムの前処理法・分析法」水中の放射性セシウムのモニタリング手法に関する技術資料検討委員会（2015）
24 JIS K 0102:2013 工場排水試験方法
25 古賀聡子，長期浮遊砂サンプリングのための簡易サンプラーの実験的検証， 筑
波大学陸域環境センター報告 5 号 （2014）156

Information 6 Concept of soil monitoring
Different methods are applied to emergency monitoring of soil, depending on the purpose ofmonitoring and the phase of nuclear emergency. For the main method among them, this section
describes the standard sampling and preparation methods and relevant matters to be noted.
As commonly-applicable matters to be noted, it is important to: 1) take measures to preventcross-contamination by using disposable gloves and frequently decontaminating equipment,
and 2) establish a procedure by paying attention to the reduction of exposure as much as
possible by, for example, transferring samples collected at a high air dose rate area to a low air
dose rate area and mixing soil samples after taking all necessary measures to prevent spreading.
Information 6.1 Measurement of radioactivity concentration in depth direction from surface(1) Method using soil sampler
A soil sampler is a cylindrical steel tube (inner diameter: 5-8 cm) with both ends open and a
sharp blade being attached to one end (Photograph 6.1), which is to be vertically hammered into
the groundto collect core samples. The sampling depth is 5, 20 or 100 cm from the groundsurface, depending on the purpose of survey. Collection of core samples using a soil sampler
takes less time than sampling using a scraper plate described below, and is effective for
evaluating depth distribution in a simplified manner. Meanwhile, this method may cause crosscontamination of samples between different layers, and does not allow high precision analysis.
Usually, soil is collected from five to nine locations per sampling site, and samples collected
for the same depth are gathered in a thick polyethylene bag. Note that, to derive coefficients toconvert measured values to figures per unit area, the sampling area and fresh soil weight (drysoil weight and dry fine soil weight as well if samples are to be dried and sieved) need to bemeasured.
A standard pretreatment method is to spread a collected sample on a tray and crush soil clods
using fingers while removing foreign matters. The sample is then mixed well until it becomeshomogeneous, and presented for measurement. In addition, to derive radioactivity concentration
per dry soil weight, a part of the sample is to be placed in a container such as a beaker, weighed,and placed in a drying oven set at 105°C to dry thoroughly. Once dried, the sample is to beweighed again to derive dry soil rate ([Dry soil weight]/[Wet soil weight]). The derived dry soil
rate is to be used forconverting measurement results. If a sample is to be dried, the sample is tobe pretreated to remove foreign matters, weighed (= wet soil weight), placed in a drying ovenset at 105°C to dry thoroughly, and then weighed again (= dry soil weight). The dried sample isto be lightly ground using a suitable tool such as mortar and pestle, sieved using a 2-mm sieve,and plant roots, small rocks, etc. are to be removed from it. This is called dry fine soil, which isthen weighed (= dry fine soil weight), mixed well until it becomes homogeneous, and presented
for measurement. For details of drying and sieving to be performed in pretreatment of sample,
refer to the Radioactivity Measurement Series No. 13 Pretreatment of Samples for Instrumental
Analysis using Germanium Detector, etc. (Reference 3).

157

Photograph 6.1
Soil samplers(2) Scraper plate
A scraper plate is a tool to sample soil by scraping the surface layer in the vertical direction at
any intervals. It consists of a metal frame to be fixed into the ground and a metal plate to scrapesoil inside the frame. (Photograph 6.2) Fixing a metal rod to the metal plate for any
selected depth enables finely adjusting the sampling depth, and therefore this method iseffective for precisely evaluating depth distribution.
A standard pretreatment method is to weigh each collected soil layer. The volume of soil isderivedfrom the internal area of frame and the layer thickness of collected soil, and soil densityof each layer is calculated. Samples are mixed well in a container such as a polyethylene bagfor each layer, filled in small containers as wet soil, and presented for measurement. For detailsof soil sampling and measurement sample preparation methods using a scraper plate, refer tothe Radioactivity Measurement Series No. 33 In-situ Measurement Using Germanium Detector(Reference 26).

Photograph 6.2
Scraper plate

158

Information 6.2 Measurement of deposits
The methods described in Information 6.1 (1) and (2) are applicable to measurement ofdeposits as well. In addition to the two methods above, the following method can also be used.
· Method using small container
After the Fukushima Daiichi Nuclear Accident, the Ministry of Education, Culture, Sports,
Science and Technology (MEXT) conducted a thorough survey on the distribution ofradioactive materials in soil. 1 In the survey, for the so much soil samples to be collected frommany sampling locations in a short period of time, MEXT adopted a simplified method tocollect and prepare soil samples for measurement using small containers (U-8 containers),
which is outlined below.
If the soil is soft, surface layer soil is collected by vertically inserting a small container into
the ground and taking the container out using a shovel along with surrounding soil. After that,the container is turned upside down, the soil surface is leveled to remove excess soil, and theremaining soil is placed in a polyethylene bag and mixed well in the bag. The mixed soil isthen returned to the small container and a cap is placed on the container. Any soil adhered tothe outer surface of the small container is wiped off, and the small container is presented formeasurement. If the soil is hard, surface layer soil is collected by vertically hammering a 100
ml metal sampling cylinder (Photograph 6.3) into the ground. The collected soil istransferred to small containers, the soil surface is leveled to remove excess soil, and theremaining processes follow the procedure for soft soil.
If measurement of deposits is involved, one has to be aware that sampling sites may not be
always an ideal bare land and how to handle plants and grass may become a problem. In thesurvey mentioned above, some survey meshes had to be grasslands as a result of considering
the requirements for taking measurements of air dose rates at same locations. In such cases,
when soil samples had weed or roots layer mixed in them, the samples had been collected into
small containers without removing such plants for measurement in past.*1
In this method, collected samples are filled into measurement containers at sampling sites,
which raises a concern over homogeneity of samples. Accordingly, a study was conducted on
homogeneity of samples in measurement containers collected by this method* 2 . The section
below summarizes the result of the study.
A comparison was made for three sampling methods: (a) samples were directly collected into
small containers and radioactivity concentration was measured without mixing; (b) after
directly collecting into small containers, samples were mixed using a disposable knife andagitated by applying vibration for 150 cycles; and (c) collected soil was placed in a bag,agitated by applying vibration while crushing soil clods in the bag, and transferred into small
containers. As a result, the method (c) produced the least unevenness in radioactivity
concentration. (Figure 6.1)

*1: Results of Investigative Study on Situation of Distribution, Etc., of Radioactive Materials Released by the Tokyo

Electric Power Company’s Fukushima Dai-ichi Nuclear Power Station (First Survey) Report on Preparation, Etc., of
Radiation Dose, Etc., Distribution Maps (Volume 1), Nuclear Emergency Response and Support Headquarters, Ministryof Education, Culture, Sports, Science and Technology (2012) (Reference 27)*2: 1st Meeting of Advisory Committee concerning Preparation of Radiation Dose, Etc., Distribution Map, Material No. 1-4-

2-1, Preliminary Survey on Distribution Status of Radioactivity in Soil in Fukushima Prefecture, Nuclear Emergency
Response and Support Headquarters, Ministry of Education, Culture, Sports, Science and Technology (2012) (Reference
28)

159

Information 6.3 Matters to be noted when selecting sampling locations
Usually, samples are collected from multiple points for each sampling site, and the number ofpoints is determined according to the planned number of sampling sites and the swiftness
required, while giving due consideration to even distribution of samples. Figure 6.2 shows aresult of a study on the unevenness of radioactivity concentration (ratio of standard deviation
to average radioactivity concentration of five soil samples (coefficient of variation)) in multiple
samples collected from one site, which was conducted as part of the survey mentioned above
where samples were collected from five points per sampling site (3 m × 3 m).*3 The result
confirmed an average coefficient of variation of 36%, in some cases exceeding 100%,
exhibiting significant variations in radioactivity concentration in general. This indicatesconsiderably uneven distribution of radioactive materials which fell to the ground surface after
the accident, even inside a small area of several square meters, due to various factors including
falling conditions, nature of soil sampled, and organic matters included in the soil. Note that, in
this survey, samples were basically collected from five points per 3 m × 3 m area, but the
number of sampling locations was reduced to between one and three for sampling sites insiderestricted areas with high radiation doses, because workers did not stay in the restricted areas
for a long period of time to control their exposure to radiation.

Photograph 6.3
100 ml metal sampling cylinder *4*3: 1st Meeting of Advisory Committee concerning Preparation of Radiation Dose, Etc., Distribution Map, Material No. 1-4-

2-1, Preliminary Survey on Distribution Status of Radioactivity in Soil in Fukushima Prefecture, Nuclear Emergency
Response and Support Headquarters, Ministry of Education, Culture, Sports, Science and Technology (2012) (Reference28)*4: Cited from the Results of Investigative Study on Situation of Distribution, Etc., of Radioactive Materials Released by the

Tokyo Electric Power Company’s Fukushima Dai-ichi Nuclear Power Station (First Survey) Report on Preparation, Etc., of
Radiation Dose, Etc., Distribution Maps (Volume 1), Nuclear Emergency Response and Support Headquarters, Ministry of
Education, Culture, Sports, Science and Technology (2012) (Reference 27)160

Cs-137 inventory (kBq/m2)

No mixing

Mixing usinga knife

Mixinginside a bag

Frequency

Figure 6.1
Chart between soil sample mixing method and radioisotope concentration (paddysoil)*5

Coefficient of variation (standard deviation/average)

Figure 6.2
Frequency of coefficient of variation ofradioactivity concentration for five samples
collected from one site
(Coefficient of variation is standard deviation of radioactivity
concentration for five samples collected from one site divided by averageradioactivity concentration)*6*5: Cited from the 1st Meeting of Advisory Committee concerning Preparation of Radiation Dose, Etc., Distribution Map,

Material No. 1-4-2-1, Preliminary Survey on Distribution Status of Radioactivity in Soil in Fukushima Prefecture, Nuclear
Emergency Response and Support Headquarters, Ministry of Education, Culture, Sports, Science and Technology (2012)(Reference 28)*6: Cited from the Results of Investigative Study on Situation of Distribution, Etc., of Radioactive Materials Released by the

Tokyo Electric Power Company’s Fukushima Dai-ichi Nuclear Power Station (First Survey) Report on Preparation, Etc., of
Radiation Dose, Etc., Distribution Maps (Volume 1), Nuclear Emergency Response and Support Headquarters, Ministry of
Education, Culture, Sports, Science and Technology (2012) (Reference 27)

161

Information 7 Masters to be noted when washing vegetables, etc.
The methods provided in this document specify that samples such as vegetables are to be
washed with water, assuming assay of radioactive materials in food and drinks based on OIL6.
For vegetables, a study was conducted on how much radioactive materials are removed bywashing with water and cooking.*1 Table 7.1 shows some of the results of the study. The
removal rate of radioactive cesium and radioactive iodine from surface-contaminated spinachby washing was 32-71% and 12-50%, respectively. As reference, data for wild edible plants arealso provided in Table 7.1. Note that, however,the removal rate varies depending on the nuclide
and the state of the surface of vegetables.
Table 7.1 Removal rate of radionuclides from surface-contaminated samples by washingMaterial
Cooking/processing
SpinachWashing under running water
Wild edible plants(Dandelion, horsetail, wildrocambole, Rumex japonicus,
butterbur, yomogi)
Washing with water in tub
SpinachWashing under running water
Wild edible plants(Dandelion, horsetail, wildrocambole, Rumex japonicus,
butterbur, yomogi)
Washing with water in tub
Wild edible plants(Dandelion, wild rocambole,
Rumex japonicus, butterbur,
yomogi)
Washing with water in tub

NuclideRemoval rate [%]No. of samples

Radioactive
cesium32 - 71 (56)13Radioactive
cesium0 - 52 (21)6Radioactive iodine

12 - 50 (33)13Radioactive iodine

9 - 46 (22)6Radioactive
tellurium

0 - 57 (29)5

Values in parentheses are averages.

*1:

Radioactive Waste Management Funding and Research Center, Removal Rate of Radionuclides by Cooking andProcessing of Food: Centering on Radiocesium Removal Rate Data in Japan, RWMC Report RWMC-TRJ-13001-2 (2013)(Reference 29) (Table partly amended)

162

References
1) 「 原 子 力災 害 対策 指 針」 原 子 力規 制 委員 会 （ 2018）2) 「 緊 急 時 モ ニ タ リ ン グ に つ い て （ 原 子 力 災 害 対 策 指 針 補 足 参 考 資 料 ） 」
原 子 力 規 制庁 監 視情 報課 （ 2017）3) 放射能測定法シリーズ No.13「ゲ ル マニ ウ ム半 導 体 検出 器 等を 用 いる 機 器 分析のための試料の前処理法」
4) 放射能測定法シリーズ No.16「環境試料採取法」
5) 栗 田 義 幸 ,三 枝 純 ,前 田 智 史 , 放 射 能 分 析 建 屋 内 へ の 放 射 性 セ シ ウ ム の 混 入 状 況
及 び 低 減 策 , 日本 放射線 安全管理 学会誌 , 第 15 巻 2 号 （ 2016）6) 「 緊 急 時 に お け る 食 品 の 放 射 能 測 定 マ ニ ュ ア ル 」 厚 生 労 働 省 医 薬 局 食 品 保 健
部 監 視 安 全 課 （ 2002）
7) 「 緊 急 時 に お け る 食 品 の 放 射 能 測 定 マ ニ ュ ア ル 」 に 基 づ く 検 査 に お け る 留 意
事 項 （ 事務連絡） 厚生労働省医薬局食品保健部監視安全課（ 2011）8) 放 射 能 測定 法 シリ ー ズ No.7「 ゲ ルマ ニ ウム半 導 体 検出 器 によ る ガン マ 線 スペ
クトロメトリー」9) 「 平 常 時 モ ニ タ リ ン グ に つ い て （ 原 子 力 災 害 対 策 指 針 補 足 参 考 資 料 ） 」 原 子
力 規 制 庁監 視 情報 課 （ 2018）10) JIS Z4336： 2010 放 射 性 ヨ ウ 素 サ ン プ ラ11) 放射能測定法シリーズ No.17「連続モニタによる環境 γ 線 測 定 法 」
12) JIS Z4325： 2008 環境 γ 線 連 続 モ ニ タ13) JIS K0216： 2014 分 析化 学 用 語 （ 環境部門）
14) JIS K0211： 2013 分 析化 学 用 語 （ 基礎部門）
15) 放射能測定法シリーズ No.29「緊 急 時に お ける ゲ ル マニ ウ ム半 導 体検 出 器 による γ 線スペクトル解析法」
16) 「 緊急時に おける食 品中 の放射性 セシウム 測定 に用いる NaI(Tl)シン チ レ ー シ
ョ ン サ ーベ イ メー タ の機 器 校 正 （ 第 2 版 ）」 , 日 本ア イ ソト ー プ協 会 （ 2011）17) 「 水 道 水等 の 放射 能 測定 マ ニ ュア ル 」厚 生 労働 省 （ 2011）18) Takahiro Nakanishi， Kazuyuki Sakuma, Trend of 137 Cs concentration in river water inthe medium term and future following the Fukushima nuclear accident, Chemosphere,
第 295 巻 （ 2019）19) 「 食 品 中の 放 射性 セ シウ ム 検 査法 」 厚生 労 働省 （ 2012）20) Multi-Agency Radiological Laboratory Analytical Protocols Manual, NUREG-1576,
EPA 402-B-04-001B NTIS PB2004-105421（ 2004）21) 廃棄物関係ガイドライン 第 5 部 放射能 濃度 等測定方 法ガイド ライ ン （ 第 2版 ） 環境省（ 2013）22) 保 高 徹 生 , 陸 水 中 に お け る 微 量 溶 存 態 放 射 性 セ シ ウ ム の 濃 縮 法 の 比 較 , 分 析
化学 66 巻 4 号 (2017)16323) 「 環 境 放 射 能 モ ニ タ リ ン グ の た め の 水 中 の 放 射 性 セ シ ウ ム の 前 処 理 法 ・ 分 析法」水中の放射性セシウムのモニタリング手法に関する技術資料検討委員会（ 2015）24) JIS K 0102:2013 工場排水試験方法
25) 古 賀 聡 子 , 長 期 浮 遊 砂 サ ン プ リ ン グ の た め の 簡 易 サ ン プ ラ ー の 実 験 的 検 証 ,筑波大学陸域環境センター報告 5 号 （ 2014）26) 放射能測定法シリーズ No.33「ゲルマニウム半導体検出器を用いた in-situ 測定法」
27) 東 京 電 力 株 式 会 社 福 島 第 一 原 子 力 発 電 所 の 事 故 に 伴 い 放 出 さ れ た 放 射 性 物 質の 分 布 状 況 等 に 関 す る 調 査 研 究 結 果 （ 第一次調査） 放射線量等分布マップの作成等に関する報告書（ 第 1 編 ）文部科学省原子力災害対策支援本部 （ 2012）28) 第 1 回放射線量等分布マップの作成等に係る検討会，配付資料第 1－ 4－ 2－ 1号， 福島県土壌放射能分布状況予備調査 文部科学省原子力災害対策支援本部（ 2012）29) 公益財団法人原子力環境整備促進・資金管理センター , 食品の調理・加工による放 射 性 核 種 の 除 去 率 ―わ が 国 の 放 射 性 セ シ ウ ム の 除 去 率 デ ー タ を 中 心 に ―, 原
環 センター 技術報告 書 , RWMC-TRJ-13001-2（ 2013）164