Issues Associated with Radiation Protection after
Fukushima Daiichi Nuclear Power Plant Disaster- Responses of and Recommendations fromJapan Health Physics Society -17 April 2012
Japan Health Physics Society

Japan Health Physics Society
1. Introduction
We express our deepest sympathy to all those affected by the Tohoku District - off the
Pacific Ocean Earthquake (Great East Japan Earthquake) and tsunami caused by theearthquake, and Fukushima Daiichi nuclear disaster, all of which have had a serious
impact on Japan. Soon after the Fukushima Daiichi nuclear disaster, Japan Health
Physics Society (JHPS) established a Q&A section on our website and has answeredquestions from the public in our capacity as a group of radiation protection experts. In
addition, we held symposia on measures for dealing with the nuclear disaster and theircriteria on 16 June 2011 and on exposure to radiation among the general public on 12
August 2011. We also held a session on the Fukushima Daiichi nuclear disaster at the44th JHPS Annual Meeting on 18 October 2011 to deepen understanding and promote
discussion about various topics related to the disaster. On 17 December 2011, we also
held a comprehensive symposium on measures for dealing with the Fukushima nuclear
disaster from the viewpoints of radiation exposure assessment and radioactive waste
management, focusing on internal exposure, to comprehensively discuss the Society’s
activities carried out over the year following the earthquake, and we identified theimportant issues associated with radiation protection to be examined in the future. The
purpose of JHPS is to widely contribute to the prosperity of humankind through thepromotion of academic and technological advances in health physics and to ensure thathuman society and industry benefit from these advances. With these aims in mind, wesummarize the issues associated with radiation protection on the basis of the findings
and lessons learned through the responses to the Fukushima Daiichi nuclear disaster,and report the response of and the recommendations from JHPS.

2. Issues associated with radiation protection and their points of discussion
On the basis of discussions during the past three symposia on Measures for Dealing
with the Fukushima Nuclear Disaster and a session on the Fukushima Daiichi nuclear
disaster at the 44th JHPS Annual Meeting in 2011, important issues associated withradiation protection can be summarized into the following eleven items in accordancewith the exposure situation that changed over time after the accident.
1) Comprehensive issues related to all situations(Issue 1) Strategies for reducing anxiety and doubts of the general public regarding
radiation risk
2Japan Health Physics Society(Issue 2) Methods of measuring ambient dose rate, surface contamination density,and concentration of radioactive materials in foods
2) Issues related to emergency exposure situation(Issue 3) Criteria for evacuation and stay in-house(Issue 4) Administration of stable iodide(Issue 5) Principles for regulation of ingestion of foods and drinks(Issue 6) Screening criteria for decontamination(Issue 7) Dose limit for emergency workers(Issue 8) Post disaster investigation of thyroid equivalent dose of radioactive iodine
3) Issues related to existing exposure situation(Issue 9) Provisional criteria for judging the safety of using school yards, forage,
cropping soil, fertilizers, bathing areas, etc.
(Issue 10) Systems for temporary entry into restricted zones(Issue 11) Management of radioactive wastes such as cesium-containing rubble,
sludge, and decontaminated soil
The points of discussion mentioned above are described below.
2.1 Comprehensive issues related to all situations
Issue 1: Strategies for reducing anxiety and doubts of the general public regarding
radiation risk
[Points of discussion] Anxiety of the general public regarding foods and drinks
Foods and drinks are daily necessities. The general public is worried about
their radiation risks in the case of daily shopping and needs information onwhether people should purchase them. It is important to understand the correct
meaning of regulatory values of foods and drinks and to verify how the actual
radiation measurements of foods and drinks are carried out and whether
measurement results are disseminated to consumers with accuracy.
 Anxiety of the general public regarding contamination hot spots
There are many cases wherein high-level radioactivity is found in sewage
sludge and incinerated ash in the Kanto district, and radioactivity relatively
higher than that in areas surrounding residential communities is observed,
whereas the amount of radiation exposure would be minimal if it is estimatedin terms of the radiation effect on the human body. It is important to respond to
the needs of local residents and properly inform them of the results of dose3

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assessments.
Anxiety of the general public regarding provisional criteria for judging the safetyof using school yards, forage, cropping soil, fertilizers, bathing areas, etc.
Although parameters and exposure scenarios for deriving these criteria are
assumed conservatively, it is important to comprehensively and correctly
disseminate the methods of deriving the criteria and their magnitude ofconservativeness.
Anxiety of the general public regarding pregnant women, fetuses, and children
The radiation sensitivities and risks of pregnant women, fetuses and children
are higher than those of adults. This high sensitivity is not considered in thecurrent domestic radiation protection system that is based on international
standards, except for the regulation for the thyroid equivalent dose for infantsin an emergency exposure situation. A simple explanation on the triviality ofradiation exposure leads to the shortage of information. A well-balanced
radiation protection system must be reconstructed, taking into consideration therelatively high sensitivity of younger individuals and comprehensive
accountability to the general public.

Issue 2: Methods of measuring ambient dose rate, surface contamination density, andconcentration of radioactive materials in foods[Points of discussion]
 Methods of measuring ambient dose rate
Some ambient dose rate meters in local governments are set on the housetops
because the measurement target is radioactive plume in the air. It is necessary
to take into consideration the measurement height dependence in the case ofradiation monitoring on broadly contaminated soil. The method of measuring
the ambient dose rate according to the monitoring objective must be
standardized, that is, to select a short time constant in the case of an overall
survey of contamination hot spots.
 Consideration of high background count rate
In many cases, Geiger-Müller (GM) survey meters for surface contamination
are usually used in measurements of surface contamination density for beta
emitters. Since this type of survey meter has a low sensitivity for gamma rays
that come from outside of the surface of a detection area, the net count rateshould be estimated in the case of measuring the surface contamination density
by subtracting the background count rate that increases with the ambient dose
rate from the measured total count rate. Such a method must be standardized.
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Japan Health Physics SocietyMethods of measuring the concentration of radioactive materials in foods
A highly accurate Ge semiconductor detector is often used to confirm thatradioactivity concentration in foods is below the regulatory values, on the other
hand, the measurement system is too expensive. Outsourcing to measure themis also expensive. For this reason, screening measurement using a NaI(Tl)scintillation survey meter that is relatively cheaper to purchase may be feasible.
In the case of such a simple screening measurement, a gamma ray shield isnecessary to reduce the background count rate accordingly. An appropriate
measurement method must be standardized, taking into consideration therelationship between the detection limit and regulatory values in foods.
Methods of estimating internal dose using whole-body counters and the bioassay
methodEstimation of internal exposure using whole-body counters and the bioassay
method depends on how to calibrate the measurement system in accordancewith radioactive nuclides and how to provide a dose coefficient assuming avariety of timings of intake, which is a significant issue that would clearlyaffect the effective dose assessment. Considering such issues, the method of
estimating the internal exposure must be standardized.
Methods of measuring a screening level for the thyroid equivalent dose ofradioactive iodine
A screening level for simplified thyroid measurement that is equivalent to 100
mSv thyroid equivalent dose for one-year-old infants was established just after
the Fukushima accident. In the case of such a simplified measurement, it isnecessary to maintain a constant distance between the survey meter and thyroidof the target person, and to subtract the background ambient dose rate from themeasured dose rate. Considering such issues, the method of measuring ascreening level for the thyroid equivalent dose of radioactive iodine must be
standardized.

2.2 Issues related to emergency exposure situation
Issue 3: Criteria for evacuation and stay in-house[Points of discussion]
 Balance among other emergency criteria (the same as Issues 4 and 5)
In the current system, the emergency criteria of evacuation and stay in-house,
distribution of stable iodide, and regulation of the ingestion of foods and drinks
are independently determined. The emergency measures are closely connected,
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that is, it is stated that stable iodide should be distributed at evacuation centersafter the evacuation instruction. It is important to determine the emergency
criteria by overlooking beyond each emergency criterion.
Assumption of long-term emergency situation and maintenance of infrastructure
including electricity, water, and communications (the same as Issue 5)
The current system assumes a short-term and temporary emergency situation.
Emergency measures applicable to a long-term emergency situation must be
examined by considering the balance with the maintenance of infrastructure
including electricity, water, and communications.
Use of SPEEDI and simulations on the diffusion of radioactive materials in theocean
The results of the System for Prediction of Environmental Emergency Dose
Information (SPEEDI) and simulations on the diffusion of radioactive
materials in the ocean must be disclosed at an early stage so that municipalities
and evacuees can actively use the data.
Communication with residents to designate the deliberate evacuation zones
Since residents in the deliberate evacuation zones have sufficient time toevacuate, the designation of deliberate evacuation zones and the deadline forthe completion of evacuation must be determined after sufficient discussions
with municipalities.
Emergency planning zones (EPZs) (the same as Issue 4)Emergency planning zones (EPZs) that are designated for emergency
preparedness within a radius of 8-10 km from nuclear power plants and related
anti-disaster measures through full discussions with municipalities must be
reviewed by considering the post disaster spread of contamination to a large
area.

Issue 4: Administration of stable iodide[Points of discussion]
 Balance among other emergency criteria (the same as Issues 3 and 5)
In the current system, the emergency criteria of evacuation and stay in-house,
the distribution of stable iodide, and regulation of the ingestion of foods anddrinks are independently determined. The emergency measures are closely
connected, that is, it is stated that stable iodide should be distributed at
evacuation centers after the evacuation instruction. It is important to determine
the emergency criteria by overlooking beyond each emergency criterion.
 Emergency planning zones (EPZs) (the same as Issue 3)
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Emergency planning zones (EPZs) that are designated for emergency
preparedness within a radius of 8-10 km from nuclear power plants and related
anti-disaster measures through full discussions with municipalities must be
reviewed by considering the post disaster spread of contamination to a large
area.
Issue 5: Principles for regulation of ingestion of foods and drinks[Points of discussion]
 Balance among other emergency criteria (the same as Issues 3 and 4)
In the current system, the emergency criteria of evacuation and stay in-house,
distribution of stable iodide, and regulation of the ingestion of foods and drinks
are independently determined. Since the emergency measures are closely
connected, it is important to determine the dose criteria for the derivation ofprovisional regulatory values for radioactive materials contained in foods byoverlooking beyond each emergency criterion.
 Assumption of emergency situation over a long-term and maintenance ofinfrastructure including electricity, water, and communications (the same as
Issue 3)The current system assumes a short-term and temporary emergency situation.
Emergency measures applicable to a long-term emergency situation must be
examined by considering the balance with the maintenance of infrastructure
including electricity, water, and communications.
 Category of foods
In the provisional regulatory values (by 31 March 2012) for radioactive
materials contained in foods before the disaster, the restriction value forradioactive iodine in fish, for example, was not specified. The categories offoods must be reviewed, taking into consideration the annual amounts ofingestion and monitoring results of actual foods.
 Scope of radioactive nuclides except for key nuclides
Provisional regulatory values (by 31 March 2012) for radioactive materials
contained in foods were derived assuming the ratio, Cs-137:Sr-90 = 1:0.1.
Since radioactive strontium tends to concentrate in bone in the food chain, theprovisional regulatory values must be reviewed by considering the results ofradiation monitoring in marine products.
Issue 6: Screening criteria for decontamination[Points of discussion]
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Japan Health Physics SocietyValidity of screening levels (100 and 13 kcpm) from the viewpoint of radiation
protection
The local nuclear emergency response headquarters increased the level ofscreening contaminated surfaces for decontamination to 100 kcpm (100,000
counts per minute) on 20 March 2011 following the advice from the Nuclear
Safety Commission of Japan. The screening level was equal to the criterion fordecontamination in the International Atomic Energy Agency (IAEA)
publication entitled “Manual for First Responders to a Radiological
Emergency”, which is equivalent to 1 μSv/h at a distance of 10cm. It was thenlowered to 13 kcpm on 16 September 2011 following the advice from theCommission that it is desirable to appropriately decrease the screening level ina stepwise manner by considering the overall situation such as radiation
monitoring results and number of people going in and out of the checkpoint.
The validity of the screening criteria for decontamination in an emergency
must be verified in terms of their effectiveness for radiation protection byconsidering the relationship between screening levels for radioactive nuclides
and effective doses owing to surface contamination remained without
decontamination in accordance with the principles of other emergency
measures.
Underestimation of count rate of GM survey meters
In many cases, Geiger-Müller (GM) survey meters have been used to measure
the radioactive contamination of surfaces. GM counters underestimate theactual count by at least 20% in the measurement range with a count rate of as
high as 100 kcpm because of the occurrence of dead time due to a longresolving time. Such an issue in radiation measurement must be included in theverification of the validity of the criteria from the viewpoint of radiation
protection.

Issue 7: Dose limit for emergency workers[Points of discussion]
 Transition of dose limit for emergency workers to 250 mSv
In the second interim report on the incorporation of the 2007
Recommendations of the International Commission on Radiological Protection(ICRP) into domestic systems, the Basic Committee of the Radiation Council
proposed to match the dose limits to internationally recommended values
because the current restriction criteria in Japan (dose limit, 100 mSv) interferedwith emergency medical care and other essential operations. On the other hand,
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the Ministry of Economy, Trade and Industry on 16 March 2011 consulted theRadiation Council to change the upper limit of individual dose for emergency
workers from 100 to 250 mSv and obtained an opinion that such a revision wasappropriate on 26 March 2011. Taking into consideration that the other various
emergency measures are based on internationally approved principles and therecommended value of the 2007 Recommendations of ICRP (emergency
medical care, no restriction; other emergency rescue operations, 1,000 or 500
mSv; other rescue operations, 100 mSv), 500 mSv must be adopted as a dose
limit for emergency workers.
Relationship between individual dose received in an emergency situation anddose limit for radiation workers under normal conditions
When the individual dose received in emergency situation is applied to control
the exposure of radiation workers under normal conditions (50 mSv per year
and 100 mSv over five years), radiation workers who have been exposed toradiation exceeding 100 mSv during emergency work are prevented fromengaging in radiation work for a given period. After this disaster, taking into
consideration that the dose limit for emergency workers was set to 250 mSv,
which is lower than the internationally recommended value, and the current
dose limit under normal conditions for radiation workers was determined on
the basis of a lifetime individual dose of 1,000 mSv, the individual dose in an
emergency should be controlled independently of a compliance of the dose
limits for radiation workers under normal conditions (50 mSv per year and 100
mSv over five years) to control radiation exposure.

Issue 8: Post disaster investigation of thyroid equivalent dose of radioactive iodine[Points of discussion]
 Simulating the atmospheric diffusion of the radioactive plume using SPEEDI
and surveys on residents’ behavior
Radiation monitoring was not satisfactorily carried out for approximately one
week after the nuclear disaster owing to its aftermath. Therefore, the results ofsimulations of the atmospheric diffusion of the radioactive plume using
SPEEDI and surveys on resident’s behavior are essential for assessing the
thyroid equivalent dose for radioactive iodine among residents after the disaster.
The thyroid equivalent dose for radioactive iodine must be estimated anddisclosed with its uncertainty on the basis of the results of simulating theatmospheric diffusion of radioactive plume using SPEEDI and surveys on
residents’ behavior.
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2.2 Issues related to existing exposure situation
Issue 9: Provisional criteria for judging the safety of using school yards, forage,
cropping soil, fertilizers, bathing areas, etc.
[Points of discussion]
 Balance among provisional criteria
As a temporary policy for judging the safety of using school yards and otheroutdoor facilities, the Ministry of Education, Culture, Sports, Science andTechnology (MEXT) initially announced a provisional criterion of 3.8 μSv/h,
which was derived from the reference level of 20 mSv/y, and decided to aim to
reduce the level of contamination to 1 mSv/y. The provisional criteria forforage fed to cows, cropping soil, and fertilizers announced by the Ministry ofAgriculture, Forestry and Fisheries (MAFF) were derived on the basis of theprovisional values for foods, which was determined with consideration of theindividual dose for radioactive cesium (5 mSv/y). In addition, the provisional
criterion for bathing areas announced by the Ministry of the Environment(MOE) was derived so that the individual dose due to external and internal
exposure was within 10% of 1 mSv/y. These provisional criteria must bereconsidered on the basis of the overall policy by considering the radiation
sensitivity of children and the balance among reference levels including and, if
necessary, adopting stepwise reference levels.
Issue 10: Systems for temporary entry into restricted zones[Points of discussion]
 Balance among radiation protection measures, inconvenience and heat stroke
During the temporary home visits allowed in summer 2011, the room
temperature reached 37 oC at some centers established as relay points throughwhich residents returned to their homes. Therefore, the requirement of wearing
Tyvek clothing was loosened to prevent heat stroke, i.e., people wearing
long-sleeved clothes and long trousers were allowed to enter the restrictedzones, although they were required to wear overshoes, gloves, a mask, and ahat. The maximum time spent at home was limited to 2 h, and the total time
taken for the round trip from the relay point to their homes was limited to 5 h.
Since the elderly were included in the list of individuals allowed temporary
home visits, flexible systems must be proposed by considering their own needs
and ages, rather than uniformly imposing the wearing of a protective suit and
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limiting the entry time.
Issue 11: Management of radioactive wastes such as cesium-containing rubble, sludge,
and decontaminated soil
[Points of discussion] Policy for managing radioactive wastes under the existing exposure situation
The radiation protection policies for the disposal of radioactive wastes in ICRP
and the Nuclear Safety Commission in Japan have been established assuming
the situation is under normal condition (planned exposure situation) where thedose limit for the public of 1 mSv/y is complied. The application of thesepolicies to the management of radioactive wastes (e.g., temporary placement,
treatment, storage, and disposal) under the existing exposure situation, where
decontamination (dose reduction) in a large contaminated area is planned by
setting reference levels chosen from between 1 and 20 mSv/y, may beunrealistic from the viewpoints of justification and optimization taking into
consideration social and economical factors. The radiation protection policy forthe management of radioactive wastes under the existing exposure situationmust be established to make the environmental restoration reasonably practical.
 Reference level for managing radioactive wastes
In the existing exposure situation, the management of radioactive wastes isjustified when the decrease in the ambient dose due to decontamination is
judged to be appropriate despite the potential exposure to radiation due to the
management of the radioactive wastes necessary for decontamination.
Justification and optimization should be fully discussed in the overall plan ofenvironmental restoration. Considering the reference level for the managementof radioactive wastes is used to reduce the ambient dose in a large
contaminated area, the reference level for the management of radioactive
wastes must be selected below the reference level for the existing ambient dosein a stepwise manner. (When environmental restoration is carried out bylowering the reference level for ambient dose due to a broadly contaminatedland in a stepwise manner during the management of radioactive wastes,
lowering the reference level for the management of radioactive wastes can beachieved by restricting the entry of the public or imposing additional shielding
measures.) How to determine the reference level for managing radioactive wastes
Stepwise approaches to decrease the individual dose should be taken by
sharing the plan of environmental restoration, including the management of11

Japan Health Physics Societyradioactive wastes, with stakeholders including local residents under the
existing exposure situation. The optimized reference level for radioactive waste
management in the existing exposure situation must be selected from the doseband (1 to 20 mSv/y) with the relevant stakeholder involvement.
Dose criteria for disposal of radioactive waste
When the temporary placement and storage are completed and the radioactive
waste management enter the disposal stage, radioactive wastes must be
disposed of in a planned manner so that the assessed individual dose becomes atarget dose of 1 mSv/y or less, which corresponds to the individual dose undernormal conditions, in line with the long-term goal of decreasing the individual
dose due to environmental radiation to less than the order of 1 mSv/y.

3. Responses of and Recommendations from JHPS
We were shocked by the Fukushima Daiichi nuclear disaster and the resulting effectsof radiation on the neighboring environment and residents. As an academic society
associated with the study of radiation protection, JHPS should continue our involvement
aiming to alleviate radiation-related problems. Our responses, such as Q&A activities
and holding symposia, and recommendations are summarized in the following sections.
3.1 Responses of JHPS
JHPS will take the following measures to address the two issues described below fromamong the issues outlined in Section 2, because the two issues are considered to becomprehensive issues related to all exposure situations rather than specific issues foreach exposure situation.
Issue 1: Strategies for reducing anxiety and doubts of the general public regarding
radiation risk
 To reduce the anxiety and doubts of the general public regarding radiation risk
and facilitate their understanding of the risk, we established a Q&A section on
our website entitled “Questions on Radiation in Everyday Life Answered byExperts” for the general public on 25 March 2011, two weeks after theearthquake. The Radiation in Everyday Life Q&A Activities Committee wasestablished by JHPS on 24 August 2011 to improve our attempts to address theconcerns of the general public. We will continue Q&A activities during the12Japan Health Physics Society

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remainder of fiscal 2012 and publish a collection of questions received andanswers given in a new booklet in fiscal 2012.
A course of lectures and explanatory sessions towards the improvement ofunderstanding of radiation effects and the technical support of daily radiation
measurements will be introduced with the aim of human resource development,such as spokespersons for radiation protection who can provide
easy-to-understand explanations, as part of a long-term strategy, whileconsidering future cooperation with other organizations. The ability of JHPS
members to explain the concept of radiation risk, cultivated through theabove-mentioned Radiation in Everyday Life Q&A activities, will also be
utilized in this project.
Discussions shall be started in expert committees towards the reestablishment ofsimple systems for protecting the public from radiation exposure, which will
require high accountability to the public, both under normal conditions and in
emergencies (including emergency and existing exposure situations),
reconsidering the scope of application of the Linear Non-Threshold (LNT)
model and the concept of radiation risk.
We will report the issues and recommendations identified through the activities
of JHPS since the Fukushima Daiichi nuclear disaster at the 13th International
Congress of the International Radiation Protection Association to be held on
13-18 May 2012 in Glasgow, Scotland, to globally disseminate the findings andlessons learned on radiation protection through the responses to the disaster.

Issue 2: Methods of measuring ambient dose rate, surface contamination density, andconcentration of radioactive materials in foods
 JHPS will examine the standardization of radiation-related emergency methods,
such as methods of measuring the ambient dose rate, surface contamination
density, and the concentration of radioactive materials in foods, methods ofevaluating the internal dose using whole-body counters and the bioassay method,and methods of evaluating the thyroid equivalent dose of radioactive iodine bysimple measurement, in collaboration with expert committees and associatedsocieties while verifying their technological validity by comparison withprevious findings and conventional technologies.
3.2 Recommendations from JHPS
JHPS offers the following recommendations for nine issues related to emergency and13

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existing exposure situations, which require specific measures on the basis of discussions
in governmental organizations or radiation protection experts, among the issues
described in Section 2. In the elaboration of these recommendations, it was emphasized
how to improve the current system of radiation protection by overlooking the various
opinions on radiation protection in an emergency. We also considered the direction
towards future goals of the radiation protection system into the recommendations by
exploiting the strength of JHPS of having many experts in radiation protection amongits members. The contents of the recommendations are described below along with their
explanations.
Issue 3: Criteria for evacuation and stay in-house
Radiation protection experts should endeavor to: Comprehensively examine the emergency measures of evacuation and stay
in-house, distribution of stable iodide, and regulation of the ingestion of foods
and drinks to ensure consistency in their principles. (the same as Issues 4 and 5)(Explanations)
In the current system, it is stated that stable iodide should be distributed at
evacuation centers, meaning that the distribution of stable iodide is assumed
after evacuation. However, the intervention levels of the thyroid equivalentdose for children were 100 mSv for the distribution of stable iodide and 500
mSv for evacuation, which contradicts the original assumption.
 Examine the adoption of both short-term moderate and long-term criteria in a
stepwise manner by considering the balance between emergency measures that
may be effective both temporarily and over a long term and the maintenance of
the infrastructure required to ensure the secure everyday life of the generalpublic. (the same as Issues 5)(Explanations)
The current system assumes stay in-house for a maximum of a few days andevacuation to evacuation centers for approximately one week and does notassume a long-term evacuation such as that required in this disaster. This
caused problems such as difficulty in maintaining the daily life of evacuees
during stay in-house over 10 days, and there is a need to newly improve theprinciples underlying the deliberate evacuation zone.
 Quickly disclose the calculation results obtained from SPEEDI and the results ofsimulations on the diffusion of radioactive materials in the ocean together with
their uncertainty in a clearly understandable form so that municipalities andevacuees can actively use the data.
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Japan Health Physics Society(Explanations)
In this disaster, the infrastructure including electricity, water, andcommunications was seriously damaged by the earthquake and tsunami, andoffsite centers were not operational. The instruction of evacuation based on
the calculation results obtained from SPEEDI was not given to local residents
and municipalities.
Thoroughly discuss issues of evacuation with municipalities to determine
suitable evacuation zones and the period of evacuation. This is necessary
because the deliberate evacuation zones, which were proposed after the disasterfor the first time, were areas in which evacuation was recommended on the basisof the annual individual dose rather than on the need for emergency evacuation.
(Explanations)
After the disaster, deliberate evacuation zones were designated on 22 April
2011 and local residents were instructed to evacuate by the end of May 2011by the government without consultation with municipalities.
Review emergency planning zones (EPZs), which are designated for emergency
preparedness within a radius of 8-10 km from nuclear power plants and related
anti-disaster measures through full discussions with municipalities byconsidering the post disaster spread of contamination to a large area as observedin this disaster. (the same as Issues 4)(Explanations)
During the disaster, radioactive contamination was spread outside the area
within 10 km of the nuclear power plants, the area within 20 km of thenuclear power plants designated as an evacuation zone, and some areas
outside this zone designated as deliberate evacuation zones.

Issue 4: Administration of stable iodide
Radiation protection experts should endeavor to: Comprehensively examine the emergency measures of evacuation and stay
in-house, distribution of stable iodide, and regulation of the ingestion of foods
and drinks to ensure consistency in their principles. (the same as Issues 3 and 5)(Explanations)
In the current system, it is stated that stable iodide should be distributed at
evacuation centers, meaning that the distribution of stable iodide is assumed
after evacuation. However, the intervention levels of the thyroid equivalentdose for children were 100 mSv for the distribution of stable iodide and 500
mSv for evacuation, which contradicts the original assumption.
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Review EPZs, which are designated for emergency preparedness within a radiusof 8-10 km from nuclear power plants and related anti-disaster measures throughfull discussions with municipalities by considering the post disaster spread ofcontamination to a large area as observed in this disaster. (the same as Issues 3)(Explanations)
During the disaster, radioactive contamination was spread outside the area
within 10 km of the nuclear power plants, the area within 20 km of thenuclear power plants designated as an evacuation zone, and some areas
outside this zone designated as deliberate evacuation zones.

Issue 5: Principles for regulation of ingestion of foods and drinks
Radiation protection experts should endeavor to: Comprehensively examine the emergency measures of evacuation and stay
in-house, distribution of stable iodide, and regulation of the ingestion of foods
and drinks to ensure consistency in their principles. (the same as Issues 3 and 4)(Explanations)
In the current system, the restriction levels for the ingestion of foods anddrinks were determined on the basis of a principle independent of the criteria
for evacuation and stay in-house.
 Examine the adoption of both short-term moderate and long-term criteria in a
stepwise manner by considering the balance between emergency measures that
may be effective both temporarily and over a long term and the maintenance of
the infrastructure required to ensure the secure everyday life of the generalpublic. (the same as Issues 3)(Explanations)
The current restriction values for the ingestion of foods and drinks were
derived by considering radioactive decay on the assumption that there is only
temporary radioactive contamination in foods, meaning that a long-term crisis
such as that resulting from this disaster was not considered. Moreover, theabsence of stepwise criteria led to confusion among the public as indicated by
the empty shelves of bottled water sold out.
 Review various types of foods and their restriction values by considering
statistical results on their annual amount of ingestion and by monitoring ofradiation in foods and following an optimization principle in which social andeconomic factors are taken into account.
(Explanations)
In the provisional regulatory value applied to foods before the disaster, for16

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example, the restriction value of radioactive iodine in fish was not specified.
To review the restriction values for representative foods, the actual states offoods for which statistics for the annual amount of ingestion are available
should be taken into account as well as contaminated foods in whichradioactive materials have been detected by radiation monitoring after thedisaster. For the monitoring results on radioactive cesium and strontium infish, for example, if the amount of radioactive strontium exceeds the assumed
level used to derive the restriction value for radioactive cesium, the former
restriction value should be reviewed. The individual dose criteria used as
references to derive the restriction values of radioactive materials in foods
should be determined after full discussion with stakeholders associated withthe production, distribution, and consumption of foods.
Issue 6: Screening criteria for decontamination
Radiation protection experts should endeavor to: Verify the validity of the screening criteria for decontamination in an emergency
in terms of their effectiveness for radiation protection in accordance with theprinciples of other emergency measures by considering problems that may arise
in relation to the radiation measurement.
(Explanations)
The local nuclear emergency response headquarters increased the level ofscreening contaminated surfaces for decontamination to 100 kcpm (100,000
counts per minute) on 20 March 2011 following the advice from the Nuclear
Safety Commission of Japan. It was then lowered to 13 kcpm on 16
September 2011 following the advice from the Commission. In many cases,
Geiger-Müller (GM) survey meters have been used to measure the radioactive
contamination of surfaces. GM counters underestimate the actual count by atleast 20% in the measurement range with a count rate of as high as 100 kcpm
because of the occurrence of dead time due to a long resolving time. The
count rate must be converted into the radiation surface density to confirm thevalidity of the criteria from the viewpoint of radiation protection, which
requires determination depending on the nuclide composition ratios forradioactive iodine and cesium.
Issue 7: Dose limit for emergency workers
Radiation protection experts should endeavor to: Examine new dose limits for emergency workers to take into account emergency
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medical care considering the facts that the adopted dose limit for emergency
workers is 250 mSv, which is lower than the internationally recommended value,
and that the current dose limit for radiation workers under normal situation isdetermined on the basis of a lifetime individual dose of 1,000 mSv. Also theindividual dose in an emergency should be controlled independently of acompliance of the dose limits for radiation workers under normal conditions (50mSv per year and 100 mSv over five years) to control radiation exposure.
(Explanations)
In the second interim report on the incorporation of the 2007
Recommendations of the International Commission on RadiologicalProtection (ICRP) into domestic systems, the Basic Committee of the
Radiation Council proposed to match the dose limits to internationally
recommended values by considering increased opportunities engaging
domestic radiation workers in the international activities, because the current
restriction criteria in Japan (dose limit, 100 mSv) interfered with emergency
medical care and other essential operations. After this disaster, the dose limit
for emergency workers was set to 250 mSv, which was lower than theinternationally recommended value of the 2007 Recommendations of ICRP
(emergency medical care, no restriction; other emergency rescue operations,
1,000 or 500 mSv; other rescue operations, 100 mSv). When the individual
dose received in emergency situation is applied to control the exposure forradiation workers under normal conditions (50 mSv per year and 100 mSv
over five years), radiation workers who have been exposed to radiation
exceeding 100 mSv during emergency work are prevented from engaging inradiation work for a given period. The emergency measures for individual
dose exposed to radiation during emergency work should be considered in acomparison with lifetime individual dose of 1,000 mSv.
Issue 8: Post disaster investigation of thyroid equivalent dose of radioactive iodine
Radiation protection experts should endeavor to: Calculate the thyroid equivalent dose for the internal exposure to radioactive
iodine on the basis of the results of simulating the atmospheric diffusion ofradioactive plume using SPEEDI, food inspections, and surveys on residents’behavior. The calculation results along with their uncertainty should be
disclosed.
(Explanations)Radiation monitoring was not satisfactorily carried out for approximately one
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week after the nuclear disaster owing to its aftermath. Therefore, the resultsof simulations of the atmospheric diffusion of radioactive plume using
SPEEDI, food inspections and surveys on resident’s behavior are essential forassessing the thyroid equivalent dose for radioactive iodine among residents
after a disaster. However, these results are considered to have highuncertainty.
Issue 9: Provisional criteria for judging the safety of using school yards, forage,
cropping soil, fertilizers, bathing areas, etc.
Radiation protection experts should endeavor to: Determine reference levels on the basis of the overall policy by considering theradiation sensitivity of children and the balance among reference levels and, if
necessary, adopt stepwise reference levels. Also, obtain the active cooperation
and understanding of stakeholders including residents to determine the reference
levels, which should not be described as permissible levels because they do notindicate a threshold between safe and hazardous levels.
(Explanations)
As a temporary policy for judging the safety of using school yards and otheroutdoor facilities, the Ministry of Education, Culture, Sports, Science andTechnology (MEXT) initially announced a provisional criterion of 3.8 μSv/h,
which was derived from the reference level of 20 mSv/y, and decided to aim
to reduce the level of contamination to 1 mSv/y. The provisional criteria forforage fed to cows, cropping soil, and fertilizers announced by the Ministry ofAgriculture, Forestry and Fisheries (MAFF) were derived on the basis of theprovisional value for foods, which was determined with consideration of theindividual dose for radioactive cesium (5 mSv/y). In addition, the provisional
criterion for bathing areas announced by the Ministry of the Environment(MOE) was derived so that the individual dose due to external and internal
exposure was within 10% of 1 mSv/y.
Issue 10: Systems for temporary entry into restricted zones
Radiation protection experts should endeavor to: Propose flexible systems that will allow people of different ages including theelderly to temporarily enter restricted zones for various purposes by considering
the balance of radiation protection measures with other risks and inconvenience,
rather than uniformly imposing the wearing of a protective suit and limiting theentry time.
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Japan Health Physics Society(Explanations)
During the temporary home visits allowed in summer 2011, the room
temperature reached 37 oC at some centers established as relay points throughwhich residents returned to their homes. Therefore, the requirement ofwearing Tyvek clothing was loosened to prevent heat stroke, i.e., people
wearing long-sleeved clothes and long trousers were allowed to enter the
restricted zones, although they were required to wear overshoes, gloves, amask, and a hat. The maximum time spent at home was limited to 2 h, and thetotal time taken for the round trip from the relay point to their homes waslimited to 5 h.
Issue 11: Management of radioactive wastes such as cesium-containing rubble, sludge,
and decontaminated soil
Radiation protection experts should endeavor to: Determine the reference levels for radioactive wastes to be below those set forbroad contamination in the overall plan of environmental restoration with theactive cooperation and understanding of stakeholders including residents, andmanage radioactive wastes so that the assessed individual dose becomes lower
than the determined reference levels. Also radioactive wastes should be disposedof in a planned manner so that the assessed individual dose becomes a target
dose of 1 mSv/y or lower.
(Explanations)
To practically and rationally carry out environmental restoration, it isnecessary to establish the policy for managing radioactive wastes (e.g.,
temporary placement, treatment, storage, and disposal) under the existing
exposure situation. The management of radioactive wastes is justified when
the decrease in the individual dose due to decontamination is judged to beappropriate despite the potential exposure to radiation due to the managementof the radioactive wastes necessary for decontamination. Justification andoptimization should be fully discussed in the overall plan of theenvironmental restoration. When environmental restoration is carried out bylowering the reference level for broad contamination in a stepwise manner
during the management of radioactive wastes, lowering the reference level forthe management of radioactive wastes can be achieved by restricting the entryof the public or imposing additional shielding measures. Such stepwise
approaches to decrease the individual dose should be taken by sharing theplan of environmental restoration including the management of radioactive
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wastes with stakeholders including local residents. Also, radioactive wastes
should be disposed of in a planned manner so that the assessed individual
dose becomes a target dose of 1 mSv/y or lower, which corresponds to theindividual dose under normal conditions, in line with the long-term goal of
decreasing the individual dose due to environmental radiation to less than theorder of 1 mSv/y.

4. Final Remarks
In this report, the responses of JHPS to the Fukushima Daiichi nuclear disaster such as
Q&A activities and the holding of symposia are reviewed, and recommendations are
summarized by considering the issues related to radiation protection. We will endeavor
to further the study of health physics and radiation protection through future discussion
and provide useful references for local residents and administrative organizations. In thenear future, we will carefully analyze the actual state of the Fukushima area to propose
recommendations in cooperation with overseas associated societies such as the Asianand Oceanic Association for Radiation Protection (AOARP), the International Radiation
Protection Association (IRPA), and the Health Physics Society in the US.

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