(Following is a draft version, which is subject to be updated or revised. Your comments and feedbacks are welcome!)
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Nuclear security threat is defined as “a
person or group of persons with motivation, intention and capability to commit
criminal or intentional unauthorized acts involving or directed at nuclear
material, other radioactive material, associated facilities or associated
activities or other acts determined by the State to have an adverse impact on
nuclear security.”[1] The IAEA recommends to take a graded approach that takes into
account: “the current evaluation of the threat, the relative ‘attractiveness’[2], the nature of the nuclear material and potential consequences
associated with the unauthorized removal of nuclear material and with the
sabotage against nuclear material or nuclear facilities”[3] to decide physical protection requirements. This suggests that the
more suitable nuclear and other radioactive material, related nuclear
facilities and activities are to achieving certain malicious intentions, the
higher the nuclear security risk is, thereby requiring a high-level of
protection measures corresponding to the security risk. In a similar way, the
larger the consequences of a certain malicious act, the stronger the level of security
measures required.
Two kinds of malicious acts, unauthorized
removal and sabotage, are present in nuclear security, and the attractiveness
of potential targets differs depending on the intention of a certain act, as does
the required protection level. The intentions of unauthorized removal are to
construct a nuclear explosive device or to disperse radioactive material
outside a facility. For the former intention, the more suitable the targeted
nuclear material is for the construction of a nuclear explosive device, the
higher the attractiveness of the material becomes, as well as the risk
involved. Sabotage acts intend to “endanger the health and safety of personnel,
the public or the environment by exposure to radiation or release of
radioactive substances by intentionally attacking or destroying a nuclear
facility or nuclear material in use, storage or transport.”[4] To this end, for the intentions of sabotage and unauthorized
removal for radioactive material dispersal, the risk increases as the consequences
can be large.
The attractiveness pertaining to unauthorized
removal intended to manufacture a nuclear explosive device indicates how much nuclear
material of interest is suitable for manufacturing a nuclear explosive device
from the viewpoint of characteristics of the material and necessary additional
processes. IAEA’s INFCIRC/225/Rev.5 categorizes nuclear material, based on its
type, composition, amount, and radioactive level, into category I, II, and III
(Table 3-1), from higher to lower in terms of attractiveness for unauthorized
removal to make a nuclear explosive device. It recommends taking protective
measures in accordance with the categorization of the material held.
While it is not possible to grasp the exact
holdings of category I nuclear material for most countries, some estimation is
possible for some countries, from the “Global Fissile Material Report 2013:
Increasing Transparency of Nuclear Warhead and Fissile Material Stocks as a
Step toward Disarmament” (discussed later), published by the International
Panel on Fissile Materials (IPFM). In addition, countries with nuclear power
plants are assumed to possess category I nuclear material and, depending on the
type of research reactors, countries without nuclear power plants but only
research reactors are possibly assumed to possess it as well.
Table 3-1 shows that plutonium and highly
enriched uranium (HEU) (isotopic concentration of uranium-235 is 20% or more) are
more attractive for manufacture of a nuclear explosive device. Among HEU,
weapon grade HEU (isotopic concentration of uranium-235 is 90% or more),best
suited to the manufacture of a nuclear explosive device, presents the highest
attractiveness as well as nuclear security risk, and thus requires a high-level
protection measures. IPFM annually publishes “Global Fissile Material Report”
that summarizes the holdings of weapon usable material of some countries, this
report refers to “Global Fissile Material Report 2013” (Table 3-2: Categorization of Nuclear
Material) for the evaluation of fissile material holdings of each country.
The holdings of HEU and plutonium of some
countries other than the ones in Table 3-2 are estimated as follows.
Ø Countries assumed to retain 1ton of HEU (category I is 5kg and more)
: Kazakhstan (10,520kg)[5]
Ø Countries assumed to retain 1kg and more but less than 1ton of HEU
(category I is 5kg and more) : Canada (less than 1,500kg), Netherland (730-810kg),
Iran (7kg), Australia (1019kg), Norway (1-9kg)[6]
Ø Countries assumed to retain 1kg and more of separated plutonium:
Netherland[7]
Even if a country does not have weapon
grade HEU or plutonium but a uranium enrichment facility or a nuclear reactor
with a reprocessing facility, the risk associated to the country is higher than
those without these facilities. Thus, the existence of nuclear power plants, research
reactors, uranium enrichment facilities, and reprocessing facilities in a
country indicates the level of risk that the country faces.
Unauthorized removal that is intended to
harm people by releasing radioactive substance outside a facility, nuclear or
other radioactive material is a target. The IAEA recommends that a State
defines the risk based on the amount, forms, composition, mobility, and
accessibility of nuclear and other radioactive material and takes prospective
measures against the defined risk[8]. As for sabotage, nuclear or other radioactive material and related
facilities are potential targets. In this regard, the IAEA also recommends that
a State “establishes its threshold(s) of unacceptable radiological
consequences”[9] and vital areas where risk associated material, device, and
functions are located “in order to determine appropriate levels of physical
protection taking into account existing nuclear safety and radiation protection.”[10] That is to suggest that,
since the risk level is determined in accordance with not only the types,
amounts/scale, and characteristics of nuclear and other radiological material
and related facilities, but also policy consideration of a State, it is
difficult to apply objective risk evaluations.
Based on this understanding, Table 3-3
below describes the presence of nuclear power plants, research reactors, uranium
enrichment facilities, and reprocessing facilities of surveyed countries, as a
risk indicator against unauthorized removal for a nuclear explosive device.
Repeating again, the possession of nuclear material usable for weapons itself
presents nuclear security risks and requires robust nuclear security measures
including enhanced physical protection systems at facilities. States with these
kinds of nuclear material have a responsibility to ensure the reliability of control
systems. In this regard, the stockpiles of fissile material that are usable for
nuclear weapons and explosive devices, and the presence of related facilities
previously discussed, are important indicators to evaluate the nuclear security
systems of surveyed countries.
(Drafted by Kazuko Hamada, Japan Atomic Energy Agency)
[1] International
Atomic Energy Agency (IAEA), “ Objective and Essential Elements of a State’s Nuclear
Security Regime,” IAEA Nuclear Security Series No. 20, 2013, p.13.
[2] This indicates the suitability to achieve malicious intents and
expresses the possible perception of potential adversaries only.
[3] International
Atomic Energy Agency (IAEA), “ Nuclear Security Recommendations on Physical
Protection of Nuclear Material and Nuclear Facilities (INFCIRC/225/Revision 5),”
IAEA Nuclear Security Series No. 13, 2011, p.14.
[4] International
Atomic Energy Agency (IAEA), “Recommendations: Nuclear Security Recommendations
on Physical Protection of Nuclear Material and Nuclear Facilities (INFCIRC/225/Revision
5),” IAEA Nuclear Security Series No. 13, 2011, p.53.
[5] James Martin Center for Nonproliferation Studies (CNS) for the Nuclear
Threat Initiative (NTI), “Civil Highly Enriched Uranium: Who Has What?”.
[6] James Martin Center for Nonproliferation Studies (CNS) for the Nuclear
Threat Initiative (NTI), “Civil Highly Enriched Uranium: Who Has What?”,
Mexico, South Africa, and Vietnam are found that they have returned the all HEU
to origin countries according to the statements in 2012 Nuclear Security Summit
and other sources and thus, removed from this list. With regard to Australia,
although it stated that it had returned HEU to an origin country, it is not
clear whether or not some HEU remains and is not removed from the list.
[7] International Panel on Fissile Materials, “Global Fissile Material
Report 2013: Increasing Transparency of Nuclear Warhead and Fissile Material
Stocks as a Step toward Disarmament,” International Panel on Fissile Materials,
October 2013.
[8] International
Atomic Energy Agency (IAEA), “ Nuclear Security Recommendations on Physical
Protection of Nuclear Material and Nuclear Facilities (INFCIRC/225/Revision
5),” IAEA Nuclear Security Series No. 13, 2011.
[9] International
Atomic Energy Agency (IAEA), “ Nuclear Security Recommendations on Physical
Protection of Nuclear Material and Nuclear Facilities (INFCIRC/225/Revision
5),” IAEA Nuclear Security Series No. 13, 2011, P.14.
[10] International
Atomic Energy Agency (IAEA), “Recommendations: Nuclear Security Recommendations
on Physical Protection of Nuclear Material and Nuclear Facilities
(INFCIRC/225/Revision 5),” IAEA Nuclear Security Series No. 13, 2013, P.14.
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