JAEA-Review-2016-012:1.46MB

JAEA-Review
2016-012
DOI:10.11484/jaea-review-2016-012
Significance of International Cooperative Research on Fission
Product Behavior towards Decommissioning of Fukushima
Daiichi Nuclear Power Station
-Review of the CLADS International WorkshopResearch Team for Fission Product Behavior
July 2016
Japan Atomic Energy Agency
日本原子力研究開発機構
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国立研究開発法人日本原子力研究開発機構研究連携成果展開部研究成果管理課
〒319-1195 茨城県那珂郡東海村大字白方 2 番地4
電話 029-282-6387, Fax 029-282-5920, E-mail:[email protected]
This report is issued irregularly by Japan Atomic Energy Agency.
Inquiries about availability and/or copyright of this report should be addressed to
Institutional Repository Section,
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© Japan Atomic Energy Agency, 2016
JAEA-Review 2016-012
Significance of International Cooperative Research on Fission Product Behavior
towards Decommissioning of Fukushima Daiichi Nuclear Power Station
-Review of the CLADS International Workshop –
Research Team for Fission Product Behavior
Japan Atomic Energy Agency
Tokai-mura, Naka-gun, Ibaraki-ken
(Received May 19, 2016)
The severe accident (SA) of Fukushima Daiichi Nuclear Power Station (1F) has
given rise to enlarged research needs for the improvement of the source term assessment.
Fission Product (FP) related researches, however, have not been widely conducted in
Japan for many years, thus a framework for such research is not so robust. The
Collaborative Laboratories for Advanced Decommissioning Science (CLADS) workshop
held in November 2015 was an important opportunity to gain the state of art knowledge
on FP and to start discussion between worldwide experts on innovative solution for 1F
issues. This report describes the outcomes of FP session conducted in the CLADS
workshop. It was pointed out during the workshop that further analyses were needed to
properly understand the phenomena that occurred in 1F. The establishment of a Japanese
FP platform is here proposed to respond to 1F issues effectively as a means to coordinate
the
national
research
efforts
and
increase
communication
between
worldwide
stakeholders. The FPs studies conducted in this frame will provide important information
for the decommissioning of 1F, and will be also of great help for the international
community to progress the knowledge on FPs behavior. Finally their outcomes could
contribute in establishing improved SA management measures.
Keywords: Fission Product, Decommissioning, Severe Accidents, Fukushima Daiichi
Nuclear Power Station, CLADS
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福島第一原発廃炉に向けた国際協力による核分裂生成物挙動評価研究の重要性
―ＣＬＡＤＳ国際ワークショップレビュー―
日本原子力研究開発機構
ＦＰ挙動研究チーム
(2016 年 5 月 19 日
受理)
福島第一原発（１Ｆ）事故は、ソースターム評価高度化のための多くの研究ニーズ、とりわ
け核分裂生成物（ＦＰ）挙動評価研究ニーズを提示した。しかしながら、日本においては長年
ＦＰ関連研究が活発に実施されてこなかった。２０１５年１１月に開催された廃炉国際共同研
究センター（ＣＬＡＤＳ）ワークショップは、１Ｆ廃炉に向けた革新的ソリューションを求め、
最新のＦＰ関連知見を収集して、専門家の間で国際的な議論を開始するための重要な機会であ
った。本報告書は、ＣＬＡＤＳワークショップの１つのセッションとして開催された「ＦＰセ
ッション」の成果を述べるものである。ＦＰセッションにおいては、１Ｆで生じた現象を適切
に理解するためには更なる炉内状況の分析が必要であり、このために必要ないくつかの研究領
域が指摘された。これを受けて、本報告書では、日本における研究活動をコーディネイトし、
多国間でのコミュニケーションを促進することにより、１Ｆの課題に効果的に応えて行くため
のＦＰ研究プラットフォームを確立していくことを提案する。本プラットフォームを利用して
実施されるＦＰ研究は、１Ｆ廃炉のための重要な情報を提供すると共に、国際的コミュニティ
がＦＰに関する知見を拡充するために役立つものと考えられる。これらのＦＰ研究の成果は、
過酷事故対策の高度化にも貢献可能である。
原子力科学研究所：〒319-1195 茨城県那珂郡東海村大字白方 2-4
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Contents
1.
Introduction
1
2.
Summary of the Presentations at the FP Session of the CLADS Workshop
3
2.1 The Behavior of FP Estimated by the Investigation of Fukushima Daiichi NPS
Units 1~3 (Mr. T. Kotaki from TEPCO)
3
2.2 Strategy for Internal PCV Condition Analysis and Needs/Expectation
for Research (Mr. A. Tatematsu from NDF)
3
2.3 An Approach toward the Evaluation of FP Behavior in NPPs under SA
(Dr. S. Uchida from IAE)
3
2.4 Volatile Fission Product Behavior and its Source Term
(Dr. P.D.W. Bottomley from ITU)
4
2.5 Recent Studies on Fission Products Behavior in a Severe Accident
(Dr. M. Gouello from VTT)
4
2.6 Fundamental Study on FP Chemistry in JAEA (Dr. K. Nakajima from JAEA)
5
3.
Summary of the FP Session and Outcomes
6
4.
Proposal of the Development of a Japanese-FP-Research-Platform
8
5.
Conclusions
9
References
Appendix A
10
Member List of Research Team for Fission Product Behavior
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目
次
1.
序論
1
2.
CLADS ワークショップ FP セッションにおける講演概要
3
2.1 福島第一原発１～３号機の調査による FP 挙動の評価（東電・小瀧）
3
2.2 格納容器内部状態解析のための戦略と研究ニーズ（NDF・立松）
3
2.3 シビアアクシデント下での原子力発電所における FP 挙動評価に向けたアプローチ
3
（IAE・内田）
2.4 揮発性核分裂生成物挙動とそのソースターム（ITU・Bottomley）
4
2.5 シビアアクシデントにおける核分裂生成物挙動についての最近の研究
4
（VTT・Gouello）
2.6 JAEA における FP 化学基礎研究（JAEA・中島）
5
3.
FP セッションまとめ及び成果
6
4.
日本における FP 研究プラットフォーム構築の提案
8
5.
結言
9
10
参考文献
付録 A
FP 挙動研究チームメンバーリスト
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図リスト
Fig.1 Summary of situation of 1F status
12
Fig.2 Summary of the research need related to 1F
12
Fig.3 An example of backward-forward evaluation
13
Fig.4 An example of revaporization tests performed in ITU
13
Fig.5 Result obtained on VTT FP tests for the influence of B on CsI
14
Fig.6 Summary of the research performed in JAEA on FP behavior
15
Fig.7 Scheme of the proposed Japanese FP Platform
16
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1. Introduction
The severe accident (SA) of Fukushima Daiichi Nuclear Power Station (1F) has given
rise to enlarged research needs for the improvement of the source term assessment. This
requires an improvement of SA analysis codes through a deep understanding of the
Fission Products (FPs) release and transport behavior. Moreover such information is
crucial for the 1F decommissioning work, since prediction of the retained FPs in the 1F is
a main concern for a rational management of worker’s radiation dose. Thus great effort is
being made towards such improvements, not only for the 1F issues but also for the
continuous improvement of source term assessment.
In Europe, a systematic FP-related research program was developed in the frame of
SARNET (Severe Accident Research NETwork of Excellence)1) and has been taken over by
the NUGENIA (NUclear GENeration II & III Association)2) network. These networks
have been an important worldwide knowledge source for the FPs behavior during SAs.
The scopes of such networks have been updated towards the ultimate goal of improved
safety of LWR considering the lessons learned from the 1F-SA. Likewise, several separate
effects tests related to the conditions of the 1F-SA have been initiated. Another important
contribution to the 1F issues will be to improve the SA analysis codes using existing
knowledge on FPs and incorporating future data from separate effects studies. In this
context, the OECD/NEA project “BSAF2” (Benchmark Study of the Accident at the 1F,
phase 2)3) is underway focusing on major issues needing clarification particularly in FP
distribution. Concerning the FP-related studies in Japan, a PIRT (Phenomena
Identification and Ranking Table) study performed by the Atomic Energy Society of Japan
(AESJ)4) has addressed specific points for the improvement of 1F source term and
decommissioning, in addition to the EURSAFE-PIRT5) (and update by NUGENIA
Technical Area 2). Thus some of the many research proposals have started, including some
in Japan, e.g. ref6), from which it is expected to improve our knowledge of FPs distribution
and their characteristics in the 1F reactor. However, a systematic approach should be
developed to combine the different individual analytical and experimental efforts.
Moreover, as FP-related researches have not been conducted in Japan for many years, a
framework for FP studies, especially for the fundamental issues, will not be so robust.
This indicates the necessity of developing a FP-research related platform in Japan, which
must be based on international collaboration.
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS) has
been established in April 2015 in JAEA and adopts a unique “bazar-type approach”
toward the 1F issues7). In the bazar-type approach many players, including research
institutes, universities, and the industries (such as constructors, manufacturers, and
operators), collaborate bringing various areas of expertise and technologies together. The
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final aim is to establish innovative solutions for the 1F decommissioning. In order to
promote the worldwide collaboration, the first CLADS workshop was held in 9-11
November, 2015, at Tokai, Japan, with the purpose of gathering all experience and
knowledge on the topics important for the 1F-SA. The workshop consisted of 1 open
session, followed by individual sessions for each subject:
1.
Debris;
2.
Severe accident progression;
3.
Fission products behavior;
4.
Waste management.
Schedule of the workshop is presented in ref.8), and this report reviews the FP individual
session in the CLADS workshop. The FP session aimed at recognizing important issues on
FP behavior for the debris-removal and waste management of 1F. This session had a
unique characteristic, as it included presentations from TEPCO/NDF (Tokyo Electric
Power Company/ Nuclear Damage Compensation and Decommissioning Facilitation
Corporation of Japan) on the research needed to promote the decommissioning of the 1F.
These were followed by presentations on the state-of-the art knowledge worldwide on FP
and on new approaches toward the evaluation of FP-behavior following a SA. Thus this
session intended to provide a bridge between the technical needs and actual fundamental
studies performed on FPs. The FP session included the following presentations:
- Mr. T. Kotaki from TEPCO showed the research needs related to FP behavior, with
special focus the current situation in 1F site.
- Mr. A. Tatematsu from NDF also presented the research needs and provided NDF
strategic plan for the decommissioning of 1F.
- Dr. S. Uchida from IAE (Institute of Applied Energy) spoke about the innovative
approach toward the evaluation of FP behavior in NPPs after a SA. He showed also the
future needs for improved FP analyses of the 1F site and the obtained analytical results.
- Dr. P.D.W. Bottomley from ITU (Institute for Transuranium Elements) introduced the
work performed in ITU on the behavior of volatile FPs. Their results and experimental
experiences were shared.
- Dr. M. Gouello from VTT (Teknologian Tutkimuskeskus VTT-Technical Research Centre
of Finland Ltd) presented the studies on FPs chemistry during a SA in Europe, showing
the results and further fundamental research needs.
- Dr. K. Nakajima from JAEA (Japan Atomic Energy Agency) made a presentation on the
fundamental study in FP chemistry performed in JAEA laboratories.
Following the presentations, a round table discussion provided a space to obtain a
common recognition of the important research issues for 1F, and to discuss possible future
follow-up meetings and a collaborative framework in response to the agreed research
needs.
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2. Summary of the Presentations at the FP Session of the CLADS Workshop
2.1 The Behavior of FP Estimated by the Investigation of Fukushima Daiichi NPS
Units 1~3 (Mr. T. Kotaki from TEPCO)
In this session, the research needs related to FP behavior were shown with a special
focus on those closely associated with the 1F current situation (Figure 1). Mr. Kotaki
showed that a difference in D/W (Dry Well) dose rate exist between Unit 1, 2, and 3 and
also in hydrogen and krypton-85 retained in S/C (Suppression chamber) space. Unit-3
dose rate in particular was 1/2 order of magnitude smaller than Unit-1, 2, and Unit-2 had
the largest dose rate. They attributed such difference to a different core melt and FP
release progression in each unit. The hydrogen and krypton-85 in S/C space did not
disappear despite the continuous purging by nitrogen injection. Consequently, it shall be
confirmed by further research. They are currently presuming that hydrogen is supplied
due to water radiolysis and from the dissolved gases in the S/C water, and krypton-85 is,
likewise, supplied due to the dissolved gases in the S/C water. However the FP behavior in
S/C has not been still fully understood. They are thus continuing various investigations
and proposed to share the new findings with the participants of the CLADS seminar.
2.2 Strategy for Internal PCV Condition Analysis and Needs/Expectation for Research
(Mr. A. Tatematsu from NDF)
In this presentation the research needs and expectations for FP behavior were shown
(a summary is presented in Figure 2), in view of the safe decommissioning of 1F. To
establish the best decommissioning practice, it is indeed essential to know the actual
conditions where immobilized FPs are present (such as position, temperature, nuclide and
chemical form). Their leaching behavior also must be known (e.g. the amount of possible
FP nuclide leached as function of pressure, temperature, and pH) due to the fact that
refloating operation are still in progress. Moreover the status of FPs in fuel debris and
their behavior under different conditions should be investigated, as this information is
necessary to the evaluation of FP release during removal of fuel debris. Such information
will be important also from the viewpoint of dose reduction and shielding during
decommissioning, and should be measured for the different parts of the containment,
such as the lower Reactor Pressure Vessel (RPV), the bottom of Pressure Containment
Vessel (PCV) and the Suppression Chamber (S/C).
2.3 An Approach toward the Evaluation of FP Behavior in NPPs under SA
(Dr. S. Uchida from IAE)
The facts learned and the phenomena that occurred in the 1F lead one to modify some
of important preconceptions on FP behavior during SAs. One possible approach to bridge
the gaps between the knowledge obtained and these preconceptions was proposed in this
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presentation (an example is shown in Figure 3 from ref.9)). The approach to the
understanding of FP behavior in 1F proposed is a backward/forward evaluation
procedures, and consist of comparing the measured data from the 1F (Backward
evaluation) with the results of SA evaluation codes (Forward evaluation). When some
gaps in the understanding and description of the phenomena are pointed out by this
method, these should be explained quantitatively based on suitable experimental and
analytical procedures. The current SA codes have been developed based on mechanistic
models, validated in the past by comparing codes results with experimental data from the
integral experiments, e.g., Phébus-FP Project10). These SA codes can be now tested and
improved by the data of the 1F. Information available for this backward evaluation
included the analyses of FP effluent to the environment and FP deposition on floors and
wall of major areas of the reactor and turbine building. As a result of evaluating the gaps
with this approach, future R&D area were proposed:
1) The suppression pool FP removal efficiency under boiling condition.
2) FP release from the suppression pool under decompression boiling condition.
3) The stability and amount of FP deposits on floors and walls.
All these information will be important to determine the decontamination practice and
the prevention of their release during decommissioning.
2.4 Volatile Fission Product Behavior and its Source Term
(Dr. P.D.W. Bottomley from ITU)
A state-of-art review of FP behavior was performed with a focus on aerosol behavior,
and chemical reactions. ITU studies on the re-vaporization of mixed irradiated fission
product deposits11) was presented (an example of such test is shown in Figure 4). The
experiments showed high re-vaporization rates for Cs (up to 90%) and the possible
re-vaporization of also other fission products (such as Mo, Te, Tc) in the temperature
range 500-1000°C. Re-vaporization was shown to be highly influenced by the
environmental conditions for Mo and Tc, while Te and Cs will re-vaporize to a high degree
both in reducing (Ar-6%H2) and oxidizing (air) conditions. These experiments showed that
the mixed deposits (condensed at ca. 700°C) can react rapidly with the atmosphere to
form various volatile forms and contribute further to the source term. However the role of
the most relevant reactions between the FPs are still not clear. Thus simpler and more
controlled experiments on FPs reaction using non-active materials were proposed.
2.5 Recent Studies on Fission Products Behavior in a Severe Accident
(Dr. M. Gouello from VTT)
A brief summary on the FPs research performed at VTT on transport and chemistry
was shown with focus on the primary circuit piping. Starting from the observation of a
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significant fraction of gaseous iodine in the containment during some of the Phébus-FP
tests10), hypotheses concerning possible reactions of cesium iodide were developed, which
can modify the transport of iodine. Moreover the experimental works, performed at
IRSN12) (Institut de Radioprotection et de Sûreté Nucléaire) on the study of the chemical
reactions in the gas stream, and performed at VTT on the surface chemical reactions on
pipe walls were presented. The {Cs-I-O-H} system and the influence that molybdenum
and boron may have on such systems were described. The influence of the two elements (B,
Mo), acting as Cs consumers in both the gaseous and condensed phases was demonstrated
(as summarized for B in Figure 5). Finally a comparative study, between the experimental
results and calculations obtained with SOPHAEROS module of ASTEC (Accident Source
Term Evaluation Code) for the transport of FP was shown, for the experiments performed
in gaseous phase and the role of possible {Cs, I, O, H} kinetic reactions was pointed out.
2.6 Fundamental Study on FP Chemistry in JAEA (Dr. K. Nakajima from JAEA)
The research target of FP-chemistry study in JAEA was presented, which is to acquire
the fundamental data required for improvement of source term evaluation and FP
distribution inside the reactor in 1F. In particular, investigation of characteristics of FP
deposits on the structural materials can be helpful to assess radiation dose of workers
during fuel debris retrieval. At present the research has focused on 4 main subjects in
terms of FP chemistry:
1. The evaluation of the effects of boron (B) release rate and thermal-hydraulic
condition on FP chemical behavior;
2. The clarification of Cs chemisorption and reaction behaviors on structural
materials at relatively high temperatures such as upper head of RPV;
3. The establishment of a database on thermodynamic and physical properties of FP
compounds formed within a reactor;
4. The development of experimental techniques for FP release and transport
reproduction tests and development of direct measurement methods for FP
chemical form.
The experimental facilities and the research topic are summarized in Figure 6. The
progress of JAEA research on such topics was reported, such as: the preliminary
calculation considering the suppressed boron release due to the formation of stable Fe-B
alloys which showed the reduction of CsBO2 and HI/I formation; the formation, in the Cs
chemisorption experiments, of an iron containing cesium silicate, CsFeSiO4; the
determination by Knudsen effusion mass spectrometry of the equilibrium vapor pressure
over solid CsBO2, and the standard enthalpy of formation of gaseous CsBO2.
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3. Summary of the FP Session and Outcomes
The FP session of CLADS workshop gave an update on 1F status and the current
knowledge on the accident progression, and introduced the research needs and approach
on FP behavior evaluation in 1F to improve source term assessment and to obtain
information for a safe decommissioning. Experts were invited to share their knowledge
and contribute with their research, as such important goals can be achieved only by a
close collaboration between worldwide expertises. The session showed that although more
analyses are needed to obtain a complete description of the accidents, the process itself
must be seen as an important occasion to learn more about SA issues.
The CLADS workshop provided, moreover, the opportunity for discussion among
experts and to identify common research goals in the frame of FP and SA research. It was
agreed that it will be of great importance to obtain real sample from the 1F (as pointed
out in the presentation of Mr. Tatematsu), as their systematic analyses could shed light
on the accident progression and on FP behavior. Some techniques were proposed to
achieve the maximum outcome from the analyses of such samples: gamma-ray
spectroscopy, alpha-ray and beta-ray spectroscopy, mass spectroscopy, XRD, XPS, Raman
spectroscopy, EPMA, SIMS, and SEM/EDX. Dr. Uchida explained how these real samples
together with an improved description of the SA progression can contribute to the
backward/forward analyses, and could finally be applied not only for the 1F analyses but
also to improve SA analysis codes. The information needed for the SA progression will
include the mass balance for water and gases, and a detailed description of their flow path
and leakage points. For such information the open database under development by
TEPCO could be an important source. Some interesting solutions were also proposed for
the evaluation of such parameters, such as the leakage path by the insertion of
radioactive tracer (e.g. U-232, Na-22/24) or by the more simple installation of measuring
device (flow-meter).
It has been further recognized that, to achieve a better description of the phenomena
occurred in 1F, separate effect tests are needed especially in the following area: aerosol
behavior, chemisorption mechanisms, re-vaporization behavior of FP deposits (as pointed
out in Dr. Bottomley’s presentation), release from debris leaching, chemistry database,
kinetics models (as pointed out in Dr. Gouello’s presentation). The relevance for 1F
application will be especially to improve the prediction of the behavior of radiologically
relevant FPs, such as Cs and I. For such elements in fact, doubts still persist on their
chemical/physical reaction with other released materials during a SA although Dr.
Bottomley and Dr. Gouello showed the state of art of the research in Europe. Dr.
Bottomley proposed indeed simpler controlled experiments using non-active materials.
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These have made in the past important progress on the understanding of FP behavior.
One such finding is that the reactions between the main volatile and semi-volatile fission
products (I, Cs, B and Mo) can significantly alter the FP behavior and so the associated
source term13). Such studies are in line with the work conducted in JAEA (see Dr.
Nakajima’s presentation). This work concentrates on FP behavior during a SA and
especially on the deposition characteristic in the reactor cooling system and containment.
These separate effect tests were proposed to be coupled with more integral experiments
(including control rod materials, such as boron) for the investigation of complex
phenomena, such as the behavior of FP in the suppression pool, especially under boiling
conditions.
The workshop was finally an important contact point between different specialist
research centers worldwide and Japanese industry, and it provided a platform prototype
for the discussion of possible collaborations in SA research and specifically in
decommissioning. In the frame of such collaborations it will be possible to contribute to
HRD (human resource development) and improve their experience in this long-term
project.
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4. Proposal of the Development of a Japanese-FP-Research-Platform
In this workshop the needs for further understanding of the phenomena that occurred
in 1F was identified. This will not only help in the decommissioning of 1F but will be of
great help for the international community to progress the knowledge of SA and FP
behavior, and finally to contribute to improved SA management measures. Therefore the
development of a national Japanese platform for FP studies is here proposed. Such
programs exist already in Europe (NUGENIA), and showed considerable progress in the
knowledge of SAs. In Japan, the FP-related researches has not been conducted for many
years, and thus a national framework is not so robust. Japanese research institutes,
universities and industries, now need to respond according to the decommissioning needs
of the 1F. The above mentioned European networks have shown that a synergetic
collaboration of different institutes, with different expertise and experimental set-ups, is
essential in unraveling and understanding the complex phenomena occurring during SA
(e.g. Phébus-FP project10)). The development of such FP platform in Japan will serve first
as a base to respond to the decommissioning needs of the 1F. The platform could also be
adopted as a Japanese branch of already existing SA networks. Some of the function
proposed for this platform are presented:
-To firstly identify the important phenomena to be investigated for the 1F-related issues,
developing a PIRT for FP research. This work is to be continuously reviewed and the
PIRT updated;
-To manage and coordinate research efforts in the Japanese FP community;
-To provide innovative solutions for 1F-related issues through the research works;
-To provide an opportunity for international knowledge exchange/transfer, and
especially between veteran and young researchers. In this frame an annual meeting
and an exchange program between institutes involved could be proposed;
-To serve as bridge among various stakeholders, permitting the coordination of needs
detected by the stakeholder with the experimental plan of different institutes
(research institutes, universities, and engineers) at the domestic level;
-To increase the communication with existing platforms (e.g. NUGENIA) by serving as a
Japanese branch for such networks. This platform could, moreover, facilitate the
process to welcome researchers from overseas.
- To provide HRD opportunities in an international environment, with a special focus on
the research opportunities to the young scientist;
-To provide basic tools and fundamental research topics including both experimental
and analytical tasks.
A proposed framework for this platform is schematically described in Figure 7. In this
system the research needs identified by the stakeholder (e.g. TEPCO, NDF) will be
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communicated to the institutes involved. The JP-FP-Platform will identify a PIRT for
them in collaboration with, for example, the AESJ. From this PIRT proposal evaluating
the expertise and available instrumentation, an experimental plan will be established,
coordinated by the institute itself and reviewed by the JP-FP-Platform. The experimental
plan will need to include and coordinate both the analytical effort, the separate effect
studies, and in a further phase, possibly, integral studies. The Backward-Forward type
evaluation method will be a fundamental instrument to connect the different
investigation methods.
5. Conclusions
The CLADS workshop was an important event to start communication between
different experts from around the world, and to share the state of art knowledge on FP (as
well as on debris and waste management) in the frame of 1F issues. The workshop
identified the needs of further understating the phenomena occurred in 1F. They will not
only help in the decommissioning of 1F but will be of great help for the international
community to progress the knowledge of severe accident and FP behavior, and finally
contribute in establishing improved SA management measures. The needs of analyzing
real samples and performing separate effect tests coupled with SA codes that have models
of the 1F events were pointed out in the workshop.
A review of the FP session was presented here, together with the outcomes and some
innovative solutions for the 1F issues. The establishment of a Japanese FP platform was
also proposed as an effective response to the identified needs and as an opportunity to
advance FP knowledge in Japan and worldwide.
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References
1) T. Haste, P. Giordano, L. Herranz, N. Girault, R. Dubourg, J.-C. Sabroux, L. Cantrel, D.
Bottomley, F. Parozzi, A. Auvinen, S. Dickinson, J.-C. Lamy, G. Weber, T. Albiol, “SARNET
integrated European Severe Accident Research—Conclusions in the source term area",
Nucl. Eng. Des., 239, pp.3116-3131 (2009).
2) J.-P. Van Dorsselaere, A. Auvinen, D. Beraha, P. Chatelard, L.E. Herranz, C. Journeau,
W. Klein-Hessling, I. Kljenak, A. Miassoedov, S. Paci, R. Zeyen, ”Recent severe accident
research synthesis of the major outcomes from the SARNET network”, Nucl. Eng. Des.,
291, pp.19-34 (2015).
3) “Benchmark Study of the Accident at the Fukushima Daiichi Nuclear Power Plant
(BSAF Project)”, OECD-NEA report NEA/CSNI/R(2015)18 (2015).
4) S. Suehiro, J. Sugimoto, A. Hidaka, H. Okada, S. Mizokami, K. Okamoto, “Development
of the source term PIRT based on findings during Fukushima Daiichi NPPs accident”,
Nucl. Eng. Des., 286, pp.163-174 (2015).
5) D. Magallon, A. Mailliat, J.-M. Seiler, K. Atkhen, H. Sjövall, S. Dickinson, J. Jakab, L.
Meyer, M. Buerger, K. Trambauer, L. Fickert, B. Raj Sehgal, Z. Hozer, J. Bagues, F.
Martin-Fuentes, R. Zeyen, A. Annunziato, M. El-Shanawany, S. Guentay, C. Tinkler, B.
Turland, L. E. Herranz Puebla, “European expert network for the reduction of
uncertainties in severe accident safety issues (EURSAFE)”, Nucl. Eng. Des., 235,
pp.309-346 (2005).
6) F. G. Di Lemma, S. Yamashita, K. Nakajima, J. Takada, M. Osaka, F. Nagase, “ Fission
products chemisorption mechanism following severe accidents: a separate effect study on
CsOH reaction with stainless steel”, “Proceeding of the MMSNF-NuFuel 2015 Workshop”,
Talk 3.9 (2015).
7) Japan Atomic Energy Agency: TOPICS Fukushima No.66 (2015), available from
http://fukushima.jaea.go.jp/english/topics/pdf/topics-fukushima066e.pdf/
(accessed 2016-3-13).
8) Japan Atomic Energy Agency: CLADS Decommissioning Workshop, available from
http://fukushima.jaea.go.jp/initiatives/cat05/haishi02002.html/ (accessed 2016-3-13).
9) S. Uchida, M. Naitoh, H. Okada, M. Pellegrini et al., “An approach toward evaluation of
FP behavior in NPPs under Severe Accidents” Proceeding of NURETH-16. 3993(2016).
10) B. Clément, R. Zeyen, “The objectives of the Phébus FP experimental programme and
main findings”, Annals Nucl. Energy, 61, pp.4-10 (2013).
11) K. Knebel, P.D.W. Bottomley, V.V. Rondinella, A. Auvinen, J. Jokiniemi, “Analysis of the
revaporisation behaviour of radioactive deposits from fission products in non-stationary
thermal conditions and constant atmosphere”, High Temp-High Press, 43, pp.139-154
(2014).
12) M. Gouello, H. Mutelle, F. Cousin, S. Sobanska, E. Blanquet, “Analysis of the iodine gas
- 10 -
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2016-012
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phase produced by interaction of CsI and MoO3 vapours in flowing steam”, Nucl. Eng.
Des., 263, pp.462-472 (2013).
13) M. Gouello, H. Mutelle, F. Cousin, S. Sobanska, E. Blanquet, “Chemistry of Iodine and
Aerosol Composition in the Primary Circuit of a Nuclear Power Plant”, “Proceedings of
LJUBLJANA 2012”, 509(2012).
- 11 -
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Fig.1 Summary of situation of 1F status
Research Needs for FP
Key issues
FP Containment
Research needs
・Characteristic of
immobilized FPs
Parameters
・Chemical properties
・FP additional release
from debris
・Temperature
・Composition
・Position
・Leakage paths
・Filtering performance
Dose reduction
and Shielding
・FP removal
Cooling
・FPs thermal
characteristic
・Chemical form
・Positon
・Decay heat
ＮＤＦの発表資料に基づき作成
Fig.2 Summary of the research need related to 1F
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Fig.3 An example of backward-forward evaluation9)
Fig.4 An example of revaporization tests performed in ITU11)
Fig.4 An example of revaporization tests performed in ITU10)
- 13 -
Fig.5 Result obtained on VTT FP tests for the influence of B on CsI
JAEA-Review 2016-012
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4
1
-
- 14 -
Fig.6 Summary of the research performed in JAEA on FP behavior
JAEA-Review 2016-012
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5
1
-
- 15 -
Fig.7 Scheme of the proposed Japanese FP Platform
JAEA-Review 2016-012
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6
1
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Appendix A Member List of Research Team for Fission Product Behavior
Name *)
Affiliation
Speakers at
Chapter
the
charge of writing
FP
in
session
Bottomley, Paul-David
ITU
X
2
Di Lemma, Fidelma Giulia
JAEA
Gouello, Mélany
VTT
X
2.5
Kotaki, Takuya
TEPCO
X
2.1
Nakajima, Kunihisa
JAEA
X
2.6
Osaka, Masahiko
JAEA
X (Chair)
Tatematsu, Atsushi
NDF
X
2.2
Uchida, Shunsuke
IAE
X
2.5
3, 4, 5
1, 3, 4, 5
*) Appeared in alphabetic order
-- 17
17 --
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国際単位系（SI）
表１．SI 基本単位
SI 基本単位
基本量
名称
記号
長
さメートル m
質
量キログラム kg
時
間
秒
s
電
流アンペア A
熱力学温度ケルビン K
物質量モ
ル mol
光
度カンデラ cd
面
体
速
加
波
密
面
表２．基本単位を用いて表されるSI組立単位の例
SI 組立単位
組立量
名称
記号
積平方メートル
m2
積立方メートル
m3
さ，速度メートル毎秒
m/s
速
度メートル毎秒毎秒
m/s2
数毎メートル
m-1
度，質量密度キログラム毎立方メートル
kg/m3
積
密
度キログラム毎平方メートル
kg/m2
比
体
電
流
密
磁界の強
(a)
量濃度
，濃
質
量
濃
輝
屈
折
率
比透磁率
積立方メートル毎キログラム
度アンペア毎平方メートル
さアンペア毎メートル
度モル毎立方メートル
度キログラム毎立方メートル
度カンデラ毎平方メートル
(b)
（数字の）　１
(b)
（数字の）　１
乗数
24
10
1021
1018
1015
1012
109
106
103
3
m /kg
A/m2
A/m
mol/m3
kg/m3
cd/m2
1
1
102
101
ゼ
タ
エクサ
Ｚ
Ｅ
10-2
ペ
テ
タ
ラ
Ｐ
Ｔ
ギ
メ
ガ
ガ
Ｇ
Ｍ
マイクロ
ノ
10-9 ナ
コ
10-12 ピ
10-15 フェムト
キ
ロ
ヘクト
デ
カ
ｋ
ｈ
da
d
°
’
日
度
分
10-3
10-6
記号
センチ
ミ
リ
ト
10-18 ア
10-21 ゼプト
10-24 ヨクト
d
c
m
µ
n
p
f
a
z
y
1 d=24 h=86 400 s
1°=(π/180) rad
1’=(1/60)°=(π/10 800) rad
”
1”=(1/60)’=(π/648 000) rad
ha 1 ha=1 hm 2=104m2
L，l 1 L=1 l=1 dm3=103cm3=10-3m3
t
1 t=103 kg
秒
ヘクタール
リットル
SI基本単位による
表し方
m/m
2
2
m /m
s-1
m kg s-2
m-1 kg s-2
m2 kg s-2
m2 kg s-3
sA
m2 kg s-3 A-1
m-2 kg-1 s4 A2
m2 kg s-3 A-2
m-2 kg-1 s3 A2
m2 kg s-2 A-1
kg s-2 A-1
m2 kg s-2 A-2
K
cd
m-2 cd
s-1
トン
表７．SIに属さないが、SIと併用される単位で、SI単位で
表される数値が実験的に得られるもの
名称
記号
SI 単位で表される数値
電子ボルト
ダルトン
統一原子質量単位
eV
Da
u
天
ua
文
単
位
1 eV=1.602 176 53(14)×10 -19J
1 Da=1.660 538 86(28)×10-27kg
1 u=1 Da
1 ua=1.495 978 706 91(6)×1011m
表８．SIに属さないが、SIと併用されるその他の単位
名称
記号
SI 単位で表される数値
バ
ー
ル bar １bar=0.1MPa=100 kPa=10 5Pa
水銀柱ミリメートル mmHg １mmHg≈133.322Pa
m2 s-2
m2 s-2
s-1 mol
(a)SI接頭語は固有の名称と記号を持つ組立単位と組み合わせても使用できる。しかし接頭語を付した単位はもはや
コヒーレントではない。
(b)ラジアンとステラジアンは数字の１に対する単位の特別な名称で、量についての情報をつたえるために使われる。
実際には、使用する時には記号rad及びsrが用いられるが、習慣として組立単位としての記号である数字の１は明
示されない。
(c)測光学ではステラジアンという名称と記号srを単位の表し方の中に、そのまま維持している。
(d)ヘルツは周期現象についてのみ、ベクレルは放射性核種の統計的過程についてのみ使用される。
(e)セルシウス度はケルビンの特別な名称で、セルシウス温度を表すために使用される。セルシウス度とケルビンの
単位の大きさは同一である。したがって、温度差や温度間隔を表す数値はどちらの単位で表しても同じである。
(f)放射性核種の放射能（activity referred to a radionuclide）は、しばしば誤った用語で”radioactivity”と記される。
(g)単位シーベルト（PV,2002,70,205）についてはCIPM勧告2（CI-2002）を参照。
表４．単位の中に固有の名称と記号を含むSI組立単位の例
SI 組立単位
組立量
SI 基本単位による
名称
記号
表し方
-1
粘
度パスカル秒
Pa s
m kg s-1
力のモーメントニュートンメートル
Nm
m2 kg s-2
表
面
張
力ニュートン毎メートル
N/m
kg s-2
角
速
度ラジアン毎秒
rad/s
m m-1 s-1=s-1
角
加
速
度ラジアン毎秒毎秒
rad/s2
m m-1 s-2=s-2
熱流密度 , 放射照度ワット毎平方メートル
W/m2
kg s-3
熱容量 , エントロピージュール毎ケルビン
J/K
m2 kg s-2 K-1
比熱容量，比エントロピージュール毎キログラム毎ケルビン J/(kg K)
m2 s-2 K-1
比エネル
ギージュール毎キログラム
J/kg
m2 s-2
熱
伝
導
率ワット毎メートル毎ケルビン W/(m K) m kg s-3 K-1
体積エネルギージュール毎立方メートル J/m3
m-1 kg s-2
電
界
の
強
さボルト毎メートル
V/m
m kg s-3 A-1
電
荷
密
度クーロン毎立方メートル C/m3
m-3 s A
表
面
電
荷クーロン毎平方メートル C/m2
m-2 s A
電束密度，電気変位クーロン毎平方メートル C/m2
m-2 s A
誘
電
率ファラド毎メートル
F/m
m-3 kg-1 s4 A2
透
磁
率ヘンリー毎メートル
H/m
m kg s-2 A-2
モルエネルギージュール毎モル
J/mol
m2 kg s-2 mol-1
モルエントロピー, モル熱容量ジュール毎モル毎ケルビン J/(mol K) m2 kg s-2 K-1 mol-1
照射線量（Ｘ線及び γ 線）クーロン毎キログラム
C/kg
kg-1 s A
吸
収
線
量
率グレイ毎秒
Gy/s
m2 s-3
放
射
強
度ワット毎ステラジアン
W/sr
m4 m-2 kg s-3=m2 kg s-3
放
射
輝
度ワット毎平方メートル毎ステラジアン W/(m2 sr) m2 m-2 kg s-3=kg s-3
酵素活性
濃度カタール毎立方メートル kat/m3
m-3 s-1 mol
ヨ
表５．SI 接頭語
記号
乗数
名称
タ
Ｙ
シ
10-1 デ
表６．SIに属さないが、SIと併用される単位
名称
記号
SI 単位による値
分
min 1 min=60 s
時
h 1 h =60 min=3600 s
（a）量濃度（amount concentration）は臨床化学の分野では物質濃度
（substance concentration）ともよばれる。
（b）これらは無次元量あるいは次元１をもつ量であるが、そのこと
を表す単位記号である数字の１は通常は表記しない。
表３．固有の名称と記号で表されるSI組立単位
SI 組立単位
組立量
他のSI単位による
名称
記号
表し方
（ｂ）
平
面
角ラジアン(ｂ)
rad
1
（ｂ）
(ｂ)
(c)
立
体
角ステラジアン
sr
1
周
波
数ヘルツ（ｄ）
Hz
力
ニュートン
N
圧
力
応
力パスカル
,
Pa
N/m2
エネルギー , 仕事 , 熱量ジュール
J
Nm
仕事率，工率，放射束ワット
W
J/s
電
荷
電
気
量クーロン
,
C
電位差（電圧） , 起電力ボルト
V
W/A
静
電
容
量ファラド
F
C/V
電
気
抵
抗オーム
Ω
V/A
コンダクタンスジーメンス
S
A/V
磁
束ウエーバ
Wb
Vs
磁
束
密
度テスラ
T
Wb/m2
インダクタンスヘンリー
H
Wb/A
セルシウス温度セルシウス度(ｅ)
℃
光
束ルーメン
lm
cd sr(c)
照
度ルクス
lx
lm/m2
Bq
放射性核種の放射能（ｆ）ベクレル（ｄ）
吸収線量, 比エネルギー分与,
グレイ
Gy
J/kg
カーマ
線量当量, 周辺線量当量,
Sv
J/kg
シーベルト（ｇ）
方向性線量当量, 個人線量当量
酸
素
活
性カタール
kat
名称
オングストローム
海
里
バ
ー
ン
Å
Ｍ
１Å=0.1nm=100pm=10-10m
１M=1852m
b
ノ
ネ
ベ
ト
パ
ル
kn
Np
Ｂ
１b=100fm2=(10-12cm) 2 =10-28m2
１kn=(1852/3600)m/s
ル
dB
ッ
ー
デ
シ
ベ
SI単位との数値的な関係は、
対数量の定義に依存。
表９．固有の名称をもつCGS組立単位
名称
記号
SI 単位で表される数値
ル
グ erg 1 erg=10-7 J
エ
ダ
ポ
イ
ア
ス
ス
トーク
チ
ル
フ
ガ
ォ
ン dyn 1 dyn=10-5N
ズ P 1 P=1 dyn s cm-2=0.1Pa s
ス St 1 St =1cm2 s-1=10-4m2 s-1
ブ sb 1 sb =1cd cm-2=104cd m-2
ト ph 1 ph=1cd sr cm-2 =10 4lx
ル Gal 1 Gal =1cm s-2=10-2ms-2
マクスウエル
ガ
ウ
ス
エルステッド（ａ）
Mx
G
Oe
1 Mx = 1G cm2=10-8Wb
1 G =1Mx cm-2 =10-4T
1 Oe　(103/4π)A m-1
（a）３元系のCGS単位系とSIでは直接比較できないため、等号「　」
は対応関係を示すものである。
キ
レ
ラ
名称
ュ
リ
ン
レ
ガ
ト
表10．SIに属さないその他の単位の例
記号
SI 単位で表される数値
ー Ci 1 Ci=3.7×1010Bq
ゲ
ン
ン R
ド rad
ム rem
マ γ
フ
ェ
ル
ミ
メートル系カラット
ト
標
準
大
気
1 R = 2.58×10-4C/kg
1 rad=1cGy=10-2Gy
1 rem=1 cSv=10-2Sv
1 γ=1 nT=10-9T
1 フェルミ=1 fm=10-15m
1 メートル系カラット = 0.2 g = 2×10-4kg
ル Torr 1 Torr = (101 325/760) Pa
圧 atm 1 atm = 101 325 Pa
カ
ロ
リ
ー
cal
ミ
ク
ロ
ン
µ
1 cal=4.1858J（｢15℃｣カロリー），4.1868J
（｢IT｣カロリー），4.184J（｢熱化学｣カロリー）
1 µ =1µm=10-6m
（第8版，2006年）

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