IAEA-SR-218/52

Australian Safeguards and Non-Proliferation Office, Canberra, Australia

Abstract

The nuclear non-proliferation regime rests on several elements that
complement and reinforce each other. The political commitment of States
against possession of nuclear weapons is reinforced by institutional measures,
the most important being IAEA safeguards. The institutional barriers can
be effectively reinforced by technological barriers against proliferation.
At the very least, technological barriers could make breakout from the
non-proliferation regime more difficult and time-consuming, thus providing
enhanced deterrence and better opportunity for the international community to
intervene. Under an integrated safeguards regime a regime that optimally
combines safeguards measures from comprehensive safeguards agreements of
INFCIRC/153-type and the Additional Protocol (INFCIRC/540) it would be
possible to give greater weight to the technological barriers to
proliferation. Under such a system fuel cycles that are inherently
proliferation resistant could be expected to produce significant benefits in
terms of reduced safeguards effort.

Introduction

Within the broader energy market there is increasing recognition that small
to medium-sized power units, placed close to regional demand centres, are a
useful supplement to large centralised power generation units. The
higher "per energy unit" cost of energy of the smaller units can be
offset by lower transmission and attendant transmission infrastructure costs.
In the recent past these smaller distributed generating units have principally
been fuelled by natural gas, but as the price of natural gas is rising
rapidly, the true cost of such generation is being realised. This is
leading to reconsideration of smaller, modular nuclear generation modalities
with the potential for lower overall costs. The use of smaller units,
distributed among regional demand centres can be expected to result in
structurally robust energy markets which are not prone to the supply
shortfalls that occur during the outages of large centralised generating
units.

Small and medium-sized nuclear reactors can be used to complement large
nuclear power units by supplying electricity, heat and desalinated water to
remote areas. In the wrong hands, however, these reactors might become a
means towards proliferation of nuclear weapons. The nuclear
non-proliferation regime allows States to have confidence that their trading
partners, neighbours and other fellow Treaty signatories are complying with
their non-proliferation commitments. It helps to ensure that material
within civil nuclear cycles is used for exclusively peaceful purposes.

The nuclear non-proliferation regime rests on several elements that
complement and reinforce each other. The political commitment of States
against possession of nuclear weapons is reinforced by institutional measures,
the most important being IAEA safeguards, which provide a high level of
assurance of compliance with obligations through international verification.

It has been argued by the authors[[1]-[2]]
(and many others) that the political commitments and institutional barriers
against proliferation, such as treaty regimes and associated verification
arrangements, can be effectively reinforced by technological barriers.
At the very least, those barriers could make breakout from the
non-proliferation regime more difficult and time-consuming, thus providing
enhanced deterrence against diversion and better opportunity for the
international community to intervene should a State be found to be in breach
of its commitments.

With the introduction the Model Additional Protocol (INFCIRC/540) and the
move towards an integrated safeguards system, technological barriers to
proliferation can be given additional weight in establishing a system of
safeguards to be applied to a State. For the State this could have the
benefit of lowering the overall intrusiveness of the international safeguards
inspection regime while still allowing the State to demonstrate its compliance
with its international commitments. For the IAEA it could have the
benefit of slowing the growth in inspection effort and associated costs,
allowing effort to be concentrated in areas of the fuel cycle of greatest
proliferation concern. Reducing the costs of safeguards has benefits for
all Member States of the IAEA as it lowers the contributions that currently
support the safeguards effort.

Starting with a discussion of the strategic value nuclear material and
reactor-associated fissile material acquisition paths, we discuss three basic
approaches to enhance proliferation resistance of small and medium-sized
reactors, namely: (1) reduction of strategic value of materials involved in
nuclear power generation; (2) incorporating reactor design features preventing
diversion of material; and (3) facilitating safeguards implementation.

The views contained in this paper are the views of the authors and not
necessarily the views of the Australian Government.

The Strategic Value of Nuclear Material

The strategic value of any particular form of nuclear material is
determined by the degree of difficulty that would be experienced in converting
the material into a weapons-useable form. Materials that are used or stored in
a form suitable for weapons have the highest strategic value.

Weapons-Useable Material

The manufacture of nuclear weapons requires either:

• pure uranium metal at very high enrichment levels (though the HEU
  category starts at 20% U-235, weapons-grade uranium comprises 93%
  or more U-235), produced in enrichment plants designed and operated for
  this purpose; or
• pure plutonium metal preferably with a very high proportion of Pu-239 (weapons-grade
  plutonium comprises less than 7% Pu-240), produced in reactors designed
  and operated to produce low burn-up plutonium, and separated from spent
  fuel or irradiation targets in reprocessing plants or plutonium extraction
  plants.

These weapons-useable materials are very different to those normally
produced in civil programs:

• low enriched uranium (LEU) typically used in light water reactors (LWRs)
  is in the range of 3-5% U-235. The utilisation of LEU as a source
  material for weapons would require chemical, enrichment and metallurgical
  processes, increasing the time frame for the production of weapons-useable
  material significantly compared to the use of HEU as the source material;
• reactor-grade plutonium (RG-Pu) from the operation of LWRs is of around
  25% Pu-240 or higher. Any attempt to utilise RG-Pu for weapons would
  encounter substantial technological challenges compared to the use of
  weapons-grade plutonium.

Material Features Affecting Its Strategic Value

The isotopic composition of the material intended for the use in
weapons could be an efficient barrier to proliferation as it directly relates
to the relative difficulty of: manufacturing a nuclear weapon with material of
a specific isotopic composition; or altering its isotopic composition to
obtain weapons-useable material. In other words, materials with a higher
isotopic proliferation barrier would require more advanced (and thus hopefully
less available) weapon designs and technology for their processing into
weapons-useable form.

Attributes that are important for determining the effectiveness of the
isotopic proliferation barrier and which need to be taken into account when
designing and manufacturing a nuclear device include:

• the critical mass of material (an attribute directly associated with its
  isotopic composition);
• the spontaneous neutron generation rate that might complicate design,
  and affect a weapon's yield and reliability;
• the heat and radiation outputs of the material.

The chemical form of material can also serve as a proliferation
barrier. This relates to the relative effort required to: refine
materials into the appropriate form; or chemically process fissile material to
separate it from accompanying diluents, contaminants or any other admixtures
that might be incorporated to frustrate chemical separation; in order to
obtain materials of sufficient purity for weapons applications.

The chemical barrier effectiveness of some of the more common materials
involved in the nuclear fuel cycle can be roughly classified in the following
order (from simplest to most difficult): pure metals, conventional compounds
(eg oxides, nitrides), mixed compounds (eg fresh MOX fuel), spent fuel,
non-conventional compounds (eg carbides and silicides), and vitrified wastes
(borosilicate glasses and titanium oxide forms).

Fissile Material Acquisition Paths Associated with Reactors

There are a variety of paths available for States that might wish to
acquire fissile material in violation of their international commitments.
One of the most important reasons for the existence of the international
safeguards regime is to have the capability to detect such violations and to
deter them by placing an element of risk that the acquisition would be
detected in a timely fashion. In order for there to be an appreciable
risk of detection, the IAEA has to consider each plausible acquisition path
and introduce measures to deal with that path in an appropriate way.

If the Agency devotes a great deal of resources to addressing one
particular material acquisition path at a facility but ignores others, then
the overall result will be less than satisfactory. The Agency must
perform a thorough "diversion path analysis" and tailor the
implementation of its safeguards efforts to address the real risks of
diversion.

Diversion of Unirradiated Direct-Use Material

There are many nuclear facilities in the world that have material that
for safeguards purposes at least is considered to be in a form directly
useable by would-be proliferators. Such material is generally referred
to as Unirradiated Direct-Use Material (UDU). This description is
applied to high enriched uranium (HEU containing 20% or more U-235),
uranium-233 and plutonium (of almost any isotopic composition) regardless of
their chemical form.

Such material can be found as fresh fuel at Materials Testing Reactors (MTRs),
Research Reactors (RRs), Critical Assemblies (CAs) and any facility which is
using HEU fuel, Mixed Oxide (MOX) fuel or any other plutonium or U-233 fuel.
UDU is the most sensitive and closely controlled material in the international
safeguards system.

There are many possible ways for a State to divert UDU material the
most obvious (and the most difficult to counter) is described as a "crash
through" approach. Under this scenario a proliferator would
simply take the material from its safeguarded storage area as soon as the IAEA
inspector had finished performing one inspection. The intention would be
to have processed the material into a form suitable for use in a weapon before
the next inspection falls due. At this point the proliferator could
declare itself to be in possession of a nuclear weapon (or weapons) and the
whole world would know that it was in breach of its safeguards obligations.

There are also certain less dramatic scenarios for the acquisition
of UDU for a State with facilities containing material of that type. For
example the operator could replace one or more items either with inactive
dummies or with dummies which in some way mimic the material taken (such as
borrowing equivalent material from another facility within the State).
The aim would be to take the risk that the statistical sampling plan applied
to the population of fresh fuel assemblies by the IAEA would fail to note the
substitution. An alternative is to take small amounts of material from
many items. The expectation would be that the small loss from many items
would be within the statistically accuracy limits of the measurement system
used by the IAEA during the inspection and consequently the overall diversion
would be undetected.

Other acquisition paths for UDU include the undeclared import of the
material or manufacturing the material from undeclared source material using
indigenous enrichment technology. Under the classical safeguards
system, formal consideration was only given to the paths that involved
acquisition from declared sources with the advent of the Additional
Protocol, measures are increasingly in place to deal with acquisitions from
any source not just declared sources.

The acquisition of fissile material from fresh fuel is a relatively
straightforward exercise and it is its very simplicity that makes it so
difficult to prevent. If a facility has a sufficient quantity of UDU
material the IAEA will generally conduct inspections on a monthly or biweekly
basis. If facility conditions make it practical, a large part of the
inventory will be covered by containment or surveillance measures and the
remaining inventory will be subject to frequent re-measurement. The aim
is to provide a heightened level of deterrence by ensuring that any diversion
would be detected in a short enough interval that even a "crash
through" scenario is unlikely to be successful before it is detected.

Diversion of Irradiated Direct-Use Material

Material that has been irradiated in a reactor normally has a high output
of heat and radiation and requires heavy shielding and special tools to be
handled or processed. Because of these special factors it is
acknowledged that acquiring material suitable for weapons from Irradiated
Direct-Use Material (IDU) is much more complicated than a similar acquisition
from UDU.

To acquire fissile material from the declared irradiated fuel from a
reactor, a proliferator would need to take either an adequate number of
complete spent fuel assemblies or a very large number of irradiated fuel pins
from a large number of assemblies. This material would need to be
transported away from the reactor in heavily shielded casks in order to deal
with both the heat and radiation generated by the assemblies or pins.
The reprocessing of the spent fuel or irradiated pins has to take place behind
massive shielding and all of the necessary equipment must be operated
remotely.

A "crash through" scenario for IDU material involves diverting
the material immediately after an IAEA inspection, but unlike the case for UDU,
the material must be reprocessed before it can be used for weapons.
Reprocessing appreciable quantities of spent nuclear fuel and producing UDU
from IDU is not something that can be accomplished very quickly. UDU can
theoretically be processed into weapons components in a matter of days, while,
even under the best of circumstances it would take some months to process IDU
to produce UDU.

There are many possible diversion scenarios for spent fuel, but as all of
these scenarios require the special handling equipment and extensive shielding
that were mentioned earlier, there are relatively simple measures that can
address a whole range of diversion scenarios.

Smaller reactor facilities generally have smaller fuel assemblies with
lower fuel loadings per assembly however, in general these factors do not
greatly simplify the tasks that must be undertaken by a would be proliferator.
Spent fuel from small power reactors, MTRs and the great majority of RRs is
intensely hot and radioactive and requires comparable levels of shielding to
large power reactor fuel in order to be handled safely.

In general, acquisition of IDU from small power reactors is much more
complicated than an equivalent diversion from an MTR or RR. MTRs and RRs
generally have means to introduce items into neutron beam lines or other
irradiation stations. As these items also require the heavy shielding
that is required to transport spent fuel they would provide a regular cover
for potential diversion activities.

The IAEA considers all of the plausible "acquisition paths" or
"diversion scenarios" in establishing a safeguards approach for a
facility. The degree of difficulty inherent in the acquisition path is
assessed, as well as the time required for successful completion. Where
engineering controls have been established that limit the possibility for the
successful completion of a particular diversion scenario it is possible to
take account of this in establishing the safeguards approach (these
engineering limitations will be discussed later in this paper). The
frequency and intensity of inspection effort is set to ensure that every
reasonably achievable acquisition path is covered by appropriate safeguards
measures.

Most commonly, this involves inspections at regular intervals with either
some form of verification activity or with the review of some form of
containment and surveillance measures to ensure that continuity of knowledge
on the spent fuel items has been maintained.

At power reactors in countries subject to the new Integrated Safeguards
regime, current plans are to remove surveillance measures from the spent fuel
pond area and rely on annual reverification of the spent fuel as the major
safeguards measure. This practical step is being taken in countries in
which the IAEA has been able to derive credible assurance as to the absence of
undeclared facilities and activities. The fissile material in spent fuel
is accessible only after reprocessing and the assurance that there is no
undeclared reprocessing capability within a State makes unnecessary the
current quarterly inspections for spent fuel.

Undeclared Irradiation

IDU material can also be produced at a range of nuclear facilities by
irradiating fertile material in the neutron flux of the core. Plutonium
can be bred from natural or depleted uranium and uranium-233 can be bred from
thorium. The degree to which this is a realistic acquisition path
depends heavily on the power output of the reactor and on the configuration of
the reactor core. In the case of MTRs and RRs it has been calculated
that in order to produce 8kg of plutonium or uranium-233 within a twelve month
period a reactor with a thermal power rating of at least 25 MW would be
required.[[3]] A similar
minimum power level would apply to small power reactors. For any power
reactor with a thermal power output greater than 25 MW (which is effectively
all power reactors), some consideration must be given to addressing the
possibility of unreported fissile material production.

Unreported fissile material production is a difficult acquisition path to
cover for MTRs and RRs (most especially those with thermal power outputs in
excess of 25 MW). The purpose of such reactors is generally to gain
access to the neutron flux on a regular basis such activities are entirely
legitimate but they would also provide the perfect cover for covert
acquisition of IDU.

In general, small power reactors present fewer possible acquisition paths
for the undeclared production of fissile material than MTRs and RRs. As
the principal purpose of a power reactor is to produce power (or in special
cases, heat and/or desalinated water) rather than neutron beams there are, in
general, greater complications involved in using such a reactor for unreported
production of fissile material.

There are some forms of power reactor that present additional opportunities
for unreported fissile material production that must be addressed when
designing a safeguards approach for the reactor.

Attention must be paid to multi-purpose small reactor designs that are
principally designed for power production but also allow access to neutron
beam ports for irradiation studies and isotope production. The Argentine
designed CAREM reactor is an example of the multi-purpose small reactor it
has the potential to be an extremely valuable contribution to the nuclear
industry but its utility needs to be taken into account in the design of
the safeguards systems applied to this new reactor type.

Special attention is paid to reactors that can be fuelled while on-line (OLRs)
these include some natural uranium fuelled graphite moderated reactors,
pebble bed HTGRs and PHWRs. The capacity to move fuel through the core
at a faster rate than has been declared opens a fissile material acquisition
path that is not readily available to more conventional reactors and the
advantage of more favourable isotopic composition from lower burnups.
The regular movements of spent fuel from the reactor also provide cover for
the movement of undeclared material (e.g. by the production of a transfer
flask with the same external appearance as a declared flask but with a greater
capacity to allow for the removal of undeclared material).

While it is clear that that some reactor designs are especially suited to
unreported production of fissile material (OLRs, multi-purpose reactors,
reactors with declared dummy assemblies and any reactor with open structural
areas within the reactor pressure vessel), there does not appear to be any
practical reactor design in which it is possible to eliminate the possibility
for unreported fissile material production entirely.

The scenario of unreported fissile material production is somewhat less
complicated in the case of reactors which only allow access to the core during
refuelling. The use of containment and surveillance measures can allow
the IAEA to derive a credible assurance that there has been no opportunity to
remove unreported fissile material from the facility and therefore, when the
inventory of spent fuel at the facility is verified, the IAEA can indirectly
derive assurance that there has been no unreported production of fissile
material.

As there are inherent difficulties involved in any attempt to "prove a
negative", the IAEA has always found the unreported production of fissile
material to be a difficult scenario to cover effectively at a number of
facilities. Relatively minor problems have to potential to prevent the
IAEA from being able to derive an independent assurance that there has been no
such unreported production of fissile material at a given facility. Any
steps taken at the design phase of the reactor to limit the opportunity to
misuse a reactor in this way will have substantial benefits for the IAEA and,
in the long run, for the operator.

Reducing the Strategic Value of Material

As mentioned earlier, we see at least three basic approaches to enhance
proliferation resistance of small and medium-sized reactors, namely: (1) by
reduction of the strategic value of the materials involved in nuclear power
generation; (2) by incorporating reactor design features preventing diversion
of material; and (3) facilitating safeguards implementation.

In general, any reduction in the strategic value of material will simplify
the task of the design of a safeguards system for the facility and make
safeguards less intrusive for the reactor operators.

Conceptually there are a number of ways in which the strategic value of the
material can be controlled:

• reduce the concentration of the fissile material (thereby increasing the
  quantity of spent fuel that must be diverted to obtain a significant
  quantity of IDU);
• increase the chemical barriers to the diversion of the material
  (producing fuel of a form that has features that present difficulties for
  reprocessing and recovery); and
• reduce the isotopic quality of the material (introduce features into the
  fuel that ensure that the final isotopic composition of the irradiated
  material is unsuitable for weapons purposes).

Reducing Concentration

Most power reactors are considered by the IAEA to be item
facilities. This means that when the IAEA is designing the safeguards
approach for the facility it considers that the fuel assemblies are to be
accounted for as discrete, identifiable, individual items. Spent fuel
items that contain less (preferably much less) than one significant
quantity (SQ) of IDU[[4]] are
subject to less intrusive safeguards than items that contain more than one SQ.
In general safeguards on a large number of items with a low fissile material
content will be less intrusive and simpler than safeguards on a small number
of items with a high fissile material content.

For example CANDU fuel bundles contain very little IDU per assembly
and, once discharged, are subject to only limited safeguards (the major
complication arising from the safeguarding of CANDU reactors relates to the
fact that fuel can be discharged while the reactor is operating).

Increasing the Chemical Barrier

If the fuel at a facility has features that render it unsuitable for
reprocessing and fissile material recovery there is a case to be made for
substantially decreasing the intrusiveness of the safeguards applied to the
facility as part of the application of an Integrated Safeguards regime.

Silicide (and to a lesser extent carbide) fuels present substantial
difficulties for existing reprocessing technologies when compared with oxide
or metal fuels. The material is not completely intractable, but the
processing of this material to recover fissile material is substantially more
difficult than for most other fuel forms and, in general, it would require far
longer conversion times to produce useable weapons components.

Under an integrated safeguards system the longer conversion times required
for fuels which cannot readily be reprocessed can be taken into consideration
in determining the inspection frequency and the intrusiveness of the
inspection measures applied to the facility. It should be noted that
choosing an intractable fuel form might have substantial fuel management
implications and it would have to be considered in the context of an overall
fuel cycle strategy.

Reducing the Isotopic Quality of the Material

Currently safeguards give only a limited recognition of the importance of
the isotopic composition of the material to its proliferation significance.
In the case of plutonium, for example, the only isotopic distinction that the
IAEA currently acknowledges relates to the proportion of Pu-238 within a given
batch of plutonium. Plutonium comprising 80% or more Pu-238 is
acknowledged as being unsuitable for explosive use. For uranium the
Agency recognises that uranium that is less than 20% enriched is of less
immediate use to a proliferator than uranium enriched to 20% or greater.

As the safeguards system develops, there may be scope for recognising
further distinctions in the isotopic composition of nuclear material.
For example, if the material in question would require extensive processing
facilities it will clearly be less desirable for a proliferator than material
that is more readily applicable for weapons use and there may be scope for
some reduction in inspection effort.

This line of reasoning can also be applied to the production of fuel for
new reactor designs. As one example, if a particular proportion of
Pu-238 degrades the utility of plutonium for explosive use, then introduction
of appropriate (possibly quite small) quantities of Pu-238 at the fabrication
stage may render the resulting spent fuel unattractive to potential
proliferators. While the "spiking" of fuel would complicate
the storage and handling of fresh fuel and have some effect upon the
reactivity of the reactor these costs may be acceptable if they result in
spent fuel that has a high intrinsic proliferation resistance. It may be
possible to reduce the safeguards applied to such material to a much lower
level than would otherwise be possible.

Design Features Preventing Diversion of Material

Radiation Field

The radiation hazard associated with nuclear material is a substantial
proliferation barrier due to the external dose potential to humans and the
damage the radiation field could inflict on the equipment and non-nuclear
materials needed to manufacture a complete operational nuclear device.
The effectiveness of radiological barriers could be characterised by the
associated dose rates or the time required for the accumulation of the lethal
dose.

Thus materials could be categorised by the degree of remote handling
required: starting with those suitable for unlimited hands-on handling and
ending up with materials requiring fully remote and/or shielded facilities.

Facility Unattractiveness

The extent to which civil nuclear fuel cycle facilities are resistant to
modifications required to convert them to the production of weapons-useable
materials is another important intrinsic proliferation barrier. Those
facilities, equipment and processes that cannot be modified to produce
weapons-useable material would have a higher proliferation barrier.

A number of attributes can be used to characterise facilities by this
criterion:

• the complexity of modifications needed to convert the facility to
  production of weapon-useable materials, including the need for additional
  specialised equipment, materials and technical knowledge;
• the availability of such specialised skills, material and knowledge to
  the country of proliferation concern;
• the safety implications of the facility's modification;
• the time and effort required to perform such modifications;
• facility throughput or, in the case of reactors, power level;
• environmental signatures associated with facility modification and
  misuse.

Access to Material

The extent to which facilities and equipment inherently restrict access to
fissile materials represents an important barrier independent from
institutional barrier including security and access controls that limit
access.

Limiting the lifting capacity of cranes in the pond area and designing the
structural limitations of the reactor area to ensure that there are only a
limited number of possible paths for spent fuel to follow can serve as a
useful adjunct to other proliferation limitation strategies.

Design Features Facilitating Safeguards Implementation at reactors

Safeguards are most easily applied to facilities in which movements of fuel
and all other general maintenance activities are conducted exclusively during
refuelling outages. Any equipment hatches must be able to be readily
sealed and remain sealed for the entire time between refuelling outages.
Provision of suitable locations for the attachment of seals should be
incorporated into hatch design. Personnel hatches should be designed so
that it is impossible for them to be used as an exit point for fresh or spent
fuel.

If spent fuel is to remain on the reactor site between refuelling
operations, it should be stored either in spent fuel ponds inside the reactor
containment building or transferred to separate storage ponds outside the
reactor containment by a transfer channel designed so that it can be readily
sealed between refuellings. Provision of suitable locations for the
attachment of seals should be incorporated in the design of the transfer
channel many existing facilities are difficult to safeguard satisfactorily
because the transfer channel cannot be sealed effectively.

If spent fuel is stored outside of the reactor containment the engineering
design of the transfer channel should be such that the only possible path for
spent fuel is between the reactor and the storage ponds. The external
storage pond area should be designed so that the only time its cask transfer
hatches need to be unsealed is when an offsite transfer of spent fuel is
taking place. Additional "safeguards-friendly" engineering
measures include ensuring that cask transfer hatches can only be opened if the
transfer channel from the reactor containment has been closed and sealed (this
ensures that there is no path for the removal of unreported fissile material
from the core).

During refuelling operations, the IAEA generally maintains continuity of
knowledge on the material in the core and covers the "unreported
production" scenario by the use of surveillance systems. Provision
of suitable places for the mounting of cameras and placement of recording
equipment should be included in the design of the reactor hall.

Choosing the Best Nuclear Fuel Cycle

Basic Criteria

There are at least three basic criteria, which are primary considerations
in the selection of the future reactor system and associated nuclear fuel
cycle:

• strategic considerations such as the State's independence of external
  energy suppliers, technological capabilities;
• economics, involving all costs, not just the cost of generating
  electricity, but the consideration of financial risks that could affect
  the investment as well;
• public acceptance factors incorporating safety, environmental
  considerations, and proliferation-resistance.

As US experts (TOPS)[[5]] have
pointed out, economics will, by far, be the principal consideration in future
decisions to build new nuclear plants. Considerations related to public
acceptance would probably be secondary to, and influenced by, those related to
economics. Commercial plant buyers are unlikely to view proliferation
resistance as a high priority, relative to economic factors.

For the large capacity nuclear generating plants that have been favoured
throughout the developed world, the capital costs of building plants and their
associated infra-structure have tended to dominate the decision making
process. The input cost of fuel has been a relatively small component of
running costs of a plant, the capital cost tends to dominate all
considerations. As these are major capital works it becomes difficult
for any concern, beyond immediate economics, to influence design
considerations delay and expense are seen as impossible barriers to
changes in plants' designs.

Plans for smaller more modular designs, with emphasis on distributed
production and responsiveness to end-consumer needs, could drastically change
these considerations as time goes forward. Physically small units, with
small power outputs and lower overall costs (though not necessarily cheaper on
a per kilowatt basis) could dominate the future deployment of nuclear power
plants. As noted earlier, the costs associated with long distance
electricity transmission and attendant transmission infrastructure tend to
limit the per kilowatt advantage that large centralised plants have over
smaller plants in the vicinity of demand centres.

With smaller capital costs and shorter deployment cycles, the concentration
of risk is less significant and the chance for concepts of proliferation
resistance to influence the overall design may become greater.

Conclusions

Developments in the nuclear industry and in nuclear technology should be
considered in the context that the overwhelming majority of countries have
given political and legal commitments against the acquisition of nuclear
weapons. These commitments are reinforced by the institutional
arrangements of the non-proliferation regime, especially by IAEA safeguards,
and also by limits on the supply of sensitive technology. Institutional
aspects of the non-proliferation regime continue to evolve, eg through
strengthened safeguards, enhanced transparency and current progress towards
Integrated Safeguards regimes as more States bring the Additional Protocol
into effect.

Consideration of safeguards issues at the design stage of small power
reactors can greatly benefit the safeguards that are applied by the IAEA to
the facility. In an appropriately designed nuclear facility, a simple
system of unobtrusive safeguards should provide confidence to the
international community that the facility does not represent a risk of
proliferation.

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