5th International Conference on
NUCLEAR OPTION IN COUNTRIES
WITH SMALL AND MEDIUM ELECTRICITY GRIDS
May 16-20, 2004 Dubrovnik, Croatia
CONFERENCE VIEWS;
CONCLUSIONS AND RECOMMENDATIONS
The Conference comprised 7
topical sessions and a poster session plus three round tables intended to give
more general discussion based on the presentations in 7 topical sessions.
Conference conclusions and recommendations were drafted by session chairmen on
the basis of discussions in their respective sessions and round tables and
proposed to the Conference participants at its Closing session. Program
Committee members finally revised, accepted, and amended conclusions and
recommendations.
Session 1. Energy Planning and Nuclear Option
Nuclear
option is here to stay and to develop– this is the shortest
summary and conclusion of the deliberations of Session 1, presented in 13
papers from 7 countries.
For nuclear to continue to
make a notable contribution to future energy supplies requires continuous
research, development and demonstration. The technology has to meet future
requirements and comply with future market expectations in terms of economics,
environment, safety and non-proliferation. The presentation of the IAEA INPRO
project described activities targeted at identifying such expectation termed
"user requirements". In the short-to-medium term – and in the absence
of a recognition of the environmental benefits of nuclear power and the fact
that most externalities of nuclear power have been already internalized – capital
costs remain a critical parameter. Current oil prices are above US$40/bbl (and
gas prices will eventually track oil prices) and this should improve the
relative competitiveness of nuclear power.
Although only a few industrialized
country use oil for base load power generation and most oil use is in
grid-disconnected markets or for peak supply, oil is the marker price for
energy in general and likely to remain for the foreseeable future.
Paper on the Monte Carlo
simulation with different capital, O&M and fuel costs for several
generating options showed that nuclear power is commercially attractive around
the mean. However, it was pointed out that for decision making distribution
tails, due to the range of assumed values, are often more important than the
mean (reflecting economic risks).
Given a generally upward
pressure on oil and gas prices and in the light of tighter environmental
constraints, limiting capital costs for nuclear power in the longer run may not
be as low as required in the short run (today), especially if carbon
constraints are institutionalized and enforced.
Several national contributions (Belarus, Czech Republic, Croatia,
Egypt, Lithuania, Romania ) presented case studies analyzing their energy
systems by appropriate computer models. The advantage, respectively, the need
to introduce or expand nuclear power was shown with main arguments of economy,
security of supply and stability of the grid created by nuclear power stations
as base load producers.
Existing nuclear power
plants are among the lowest cost, if not the lowest, electricity producers in
many countries and regions. Hence, economic reason strongly suggests their
continued operation including lifetime extension as long as all regulatory and
safety requirements are met. Especially in countries with economies in
transition, affordable electricity is a prerequisite in the economic catch-up
process. As the presented Lithuanian case demonstrates, politically motivated
closure dates for nuclear power are economically nonsense. Either a plant is
considered (by the independent and competent
regulator) to be safe for an operating license or it has to be shut down
immediately. But picking a politically motivated date for closure bears neither
relation to safety or economics.
Finally, if nuclear power in longer term wants to make a substantial contribution to sustainable development, it must penetrate markets other than electricity. Transportation is the most difficult market, as oil products seem to have an overwhelming comparative advantage. Nuclear power derived hydrogen is one of the few fuels that could meet many of the environmental and supply security objectives. There are numerous obstacles on the way to a hydrogen economy (lack of infrastructure, end-use devices, costs, acceptance, etc). But nuclear hydrogen is available today through simply electrolysis, and more efficiently by high temperature reactors, which can be available in few years. So if needed nuclear stands ready. The economics of nuclear hydrogen must be evaluated in the context of the full energy system including end-use devices such as fuel cells. Only then will the environmental and economic benefits come to the fore.
Papers presented in the session 2. documented interest of several countries to develop new reactor design or in adapting present designs for power generation. The aim of innovative reactor concepts is to resolve problems with present generation of NPPs in the area of economics, safety and fuel cycle. Most reactor concepts are of smaller size (300 MW or less) with the aim to reduce investor risks. Power produced in the reactors could be readily used in water desalinization and cogeneration processes. On the demand fuel cycle back-end services or regional fuel cycle centers could be arranged. A possibility of leasing NPPs to the users, where the supplier takes care of plant operation, fuel cycle and waste disposal has also been considered. Economy of scale could be compensated with simplicity of design and possibility of modular plant construction. Most reactor concepts presented in the session will be ready for deployment in next 10-15 years or earlier. New design of Medium and Small Sized Reactors (SMRs) were presented by participants from Russian Federation, Japan and USA. Particular attention has been dedicated to IRIS reactor whose conceptual design is in the development phase by an international consortium (including Faculty of Electrical Engineering and Computing from Zagreb, Croatia).
Participants of the roundtable agreed that promotion of certain infrastructure changes, such as establishment of interregional waste repositories and reciprocity in design certification and licensing between vendor countries and users may be not less important for the deployment of advanced NPPs than the technology development itself. Topics addressed included advantages of nuclear power in limiting carbon dioxide emissions and possible role of the Kyoto protocol possibilities.
For licensing of innovative SMRs in user countries demonstration or prototype plant may be required or, when basic reactor concept is not far from present plants, an assurance that systems and components included in new design are proven in operation. The latter is particularly true for more innovative designs, such as Generation-IV systems. Several participants of the roundtable pointed to a continuous character of nuclear technology development, which makes the efforts on near-term and longer-term NPP designs equally important for overall success in the promotion of nuclear power.
Experience from managing and operating Nuclear Power Plants was
presented through 31 contributions to this section. 18 oral and 13 posters from
11 countries were divided in three sub-sessions:
-
Strategic and long term activities
-
Operating experience
-
Inspections and diagnostics
Management tools and processes significantly contributing to safe and
reliable plant operation, were focused upon :
-
Equipment Performance and Material Condition
-
Operating Experience, Internal and Independent External Reviews and
Industry Information Exchange
-
Safety Improvements and Plant Upgrades
-
Human resource management, performance and safety culture
Mature operating nuclear facilities identify human factor as having a significant potential impact on nuclear safety. Qualification, training, human resource management and especially safety culture are identified as the major contributors.
The same facilities devote a
significant part of their resources to modifications, replacements and
refurbishment, resulting in improved safety, reliability and economics (shorter
outages, power uprates).
Safety commitments are
complied with through maintenance, surveillance and inspection programs which
have a great impact on the operational costs of the plant. It is very important
to take into account their effectiveness and the quality of information.
The ten year comprehensive
Periodic Safety Review , by means of predefined state of the art methods,
confirms compliance to plant safety objectives and practices as well as
licensing regulatory requirements.
The four above mentioned
programs provide the plant management with a clear overview of the plant
status, the equipment and material condition; making it a crucial input for
decision making regarding equipment substitutions and especially plant upgrades
issues.
Presentations and
discussions addressing pressing industry issues (e.g. Reactor Head Vessel)
confirmed the conference meets the current needs of the audience.
Another very important
aspect is operating experience. Corrective and preventive programs; the
necessity of sharing information about good practices and events throughout the
industry, and therewith initiating, establishing and promoting internationally
recognized and accepted industry standards of excellence.
Bearing in mind favorable changes in political and public opinion recognizing nuclear power as a viable option in meeting energy demands, safety improvements at existing facilities and new technical solutions; in the current dynamic, market opening (deregulated) environment, with continuous media exposure, implementation of approved, recognized and proven solutions is of utmost importance.
Twenty-four papers in
Session «Nuclear Safety Analysis» were divided in three groups: Deterministic
Safety Analyses, Probabilistic Safety Assessment (PSA) and safety of the new
IRIS reactor.
Within deterministic safety
analyses the application of accident analysis tools to the different reactor types
is shown. Several important topics were addressed.
In the application of the
FFTBM method for the accuracy quantification the importance of the time window
selection was investigated.
The analysis of a Station
Blackout (SBO) event in a VVER-1000 is carried out by two different codes. In
the case of the severe-accident scenarios, large differences in the timing of
key-events are calculated, although the sequence of the key-events is basically
the same. This gives an idea of the uncertainty that characterize the
prediction of such extreme plant scenarios.
The characteristics of SMART
innovative reactor in Korea are presented based on calculation of the
parameters that affect plant’s natural circulation performance.
For the Krško plant two
severe accident scenarios are calculated using MAAP and Relap5/SCDAPSIM codes.
One paper deals with the application of the PARET code to the analysis of a reactivity excursion transient in a research reactor.
Hydrogen behavior and
containment responses were analyzed in several papers. MAAP code, ASTEC code
and COCOSYS code were applied for PWR and RBMK reactors. Hydrogen generation is
investigated in the case of SBO in VVER by using Relap5-SCADAP and MELCOR code.
Six papers were related to
the Probabilistic Safety Assessment (PSA).
Three of them were presented orally.
The papers were covering
some of the most current PSA related topics: (1) PSA update, (2) Uncertainty,
(3) Risk indicators, and (4) Safety standards.
Two papers related to PSA update discuss initiating events frequency update and system failure probabilities update for PSA emphasizing the necessary steps for keeping PSA up to date with NPP operation experience.
One paper analyses
uncertainty estimation for initiating events frequency concluding that uncertainty
estimation is critical element for various risk informed applications.
Two papers have presented
work related to PSA application for nuclear power plant safety level and
quantitative risk indicators determination underlining the practical
applications of PSA for relating plant operating condition to safety and risk.
One paper discusses IAEA
safety standards and approach to safety determination of advanced
reactors. This effort is based on broad
experience acquired during preparation of IAEA safety standards for existing
reactors.
Presented work shows PSA
maturity, importance and relevance for safe and economical NPP operation.
Covered topics are of highest importance for keeping nuclear energy viable
option now and in the future. To keep current topics
and introduce topics of various risks informed applications is the
recommendation for future themes related to PSA.
A special sub-session on
IRIS safety and design consisted of seven papers. The first three papers gave a
comprehensive update of the work done so far on the analysis of Small Break
Loss of Coolant Accidents (SBLOCA). Several analytical results showing the
evolution of the most significant parameters were presented. The calculations
were performed using RELAP5, GOTHIC and MELCOR computer codes. The calculation
took into account the strong interaction between the reactor vessel and the
containment of the IRIS. Comparisons of the results obtained with RELAP and
MELCOR in two integral separated calculations were presented and the
differences on the results of the two calculations were investigated and
explained.
One paper was devoted to the
examination of different fuel management options taking into consideration the
influence of the cycle length on the reloading strategy, including a two-batch
and three-batch reloading. A reference two-batch core design has been developed
for the first cycle, as well as for the transition cycles leading to
equilibrium cycle. This design provides boundary conditions for the safety
analysis.
One paper presents a simulation
tool for the tasks related to dynamics and control. This tool was developed
according to concepts of modularity, openness, efficiency and reliability of
the software. The simulator, initially developed for industrial purposes, has
been improved with specific models for the dynamic simulation of IRIS.
Preliminary results were presented.
In the paper with the
conceptual design of the IRIS pressurizer, the most relevant functional
requirements are summarized and the means for their implementation including
the models used for the analysis.
One paper addresses the use of the computational fluid dynamics (CFD) in the design process of IRIS reactor. The key objective is to use CFD as a design tool for virtual tests to reduce the effort for the optimization of the design of components and to support the IRIS testing program.
The Session 5 Radioactive
Waste Management and Decommissioning consisted of 2 poster presentation and 5
orally presented papers. Important characteristic of this year’s conference
regarding subject of Session 5 was that two papers covered decommissioning plan
for NPP Krško what is the issue which have to take more attention in the next
conferences.
In addition the roundtable
titled Interregional Repository Site for Radioactive Waste has been conducted
by several experts already acknowledged in promoting or opposing regional
approach in radioactive waste management.
To date, multinational
co-operation on radioactive waste disposal has been largely limited to R&D
(e.g. many examples in the European Community sponsored research programmes on
disposal). There are multiple examples and various kinds of multinational
co-operation in radioactive waste management (e.g. outside the strict disposal
area cooperation exists in the nuclear fuel cycle). A need for multinational
co-operation in the disposal area has been expressed by a number of Member
States of the IAEA. (e.g. the Netherlands and Switzerland). IAEA produced in
1998 a technical document outlining important factors to be considered (such as
technical and scientific factors). IAEA is updating and extending the earlier
technical document, taking into account developments since its publication. The
new document will also deal with repositories for all kinds of radioactive
wastes, including spent radioactive sources, as this may reflect a broader area
of interest.
The topics suggested for the
discussion at the roundtable included socio-political factors
(factors on non-technocratic character) in favor of international waste
repositories, successful examples of exporting toxic waste other than nuclear
for final disposal in other country, and who should take initiative in for
international repository: governments or private sector?
The discussions at the
roundtable identified that changes in regional geopolitical structure, such as
collapse of the former Soviet Union and its ‘Eastern block’ and growth of the
European Union, as well as the tendency for increased regional cooperation, such
as observed in Latin America and between several CIS countries may result in
the changed pattern of nuclear infrastructure sharing and therefore may be the
factors in favor of international repositories.
Several examples of the
on-going export of non-nuclear toxic waste from Croatia and Slovenia for final
disposal in Germany were mentioned.
Regarding the role of
private sector, it was suggested that governmental involvement is likely to be
needed for the case of international waste repositories, like for any other
nuclear related international effort.
Finally, it was stressed
that once a country wants to offer its capacities for an international waste
repository, drawing the roadmap that leads to an actual international
repository can be viewed as the necessary first step. To date, there are no
signs that any country has prepared or is preparing such a roadmap. Since
accordingly international repository so far does not look yet realistic,
national solutions have not to be neglected, particularly in order to keep
credibility for the national disposal option and for the nuclear option in
energy and applications.
Also, on the margins of the
conference the second meeting of so-called Ljubljana Initiative has been held
aimed to find out rough role that the initiative have to get, but not
duplicating SAPHIER Project and ARIUS activities.
Public relation issues are
one of the most important in the nuclear field. Any activity has to be nowadays
supported by public relation campaign in order to achieve planned objectives.
Especially is that true for the radioactive waste management related projects.
Public opposition towards any activity connected to waste management demand
special treatment.
In this session 8 abstracts
were proposed. From them 4 were accepted for presentation on the conference: 3
oral presentations (from Bulgaria, Slovenia and Croatia) and 1 poster (from
Croatia). Although the presenters from Bulgaria could not be present on the
conference, other 3 paper show growing need for communication with public and
their different involvement in the projects. The depth of their participation
depends on the project and its objectives but has to be systematically
addressed according to the needs. The presented cases in the papers demonstrated
that public relation issues should become more and more important and that
disseminating of used approaches is of great value to the nuclear field.
Round
Table 3. - HARMONISATION OF NUCLEAR LIABILITY REGIMES IN EUROPE
During the Session 7. of
this Conference, through 6 general and 3 national reports, we have learned
about the current status and major provisions concerning the Paris Convention
recent revision and obtained a discussion relating to the liability limits and
insurance for nuclear damage as well as about the different approaches in some
countries in adopting their legislation. We have also learned about the
adoption of the Protocol to Amend the Vienna Convention and the Convention on
Supplementary Compensation for Nuclear Damage, within the Vienna Convention
countries and the current status of their signature and/or ratification. Beside
these more general matters we put a special emphasis on the problem of
terrorism risk coverage examining the solutions applied in some countries on
how to cover these risks through the insurance pools and/or by governments
(states) support and/or by other schemes in the worldwide practice.
It is obvious that the
ongoing process of adopting the Nuclear Liability legislation within the
Paris/Brussels Convention and Vienna Convention countries will go on for the
next few years. The ratification of, or the accession to the revised
conventions is the first step before any changes in the national legislation
within these countries could be foreseen. Still we were informed about the
increased liability limits of the operators in some European countries, even
before the complex revision of the nuclear liability legislation, based on the
a.m. conventions, has been adopted.
As concern the Vienna
Convention countries the adoption of the Protocol to Amend the Vienna
Convention of 1997, based on the accession and/or ratification of this
Protocol, doesn’t give to much optimism that its implementation in the national
legislation could be realized soon. Even more, this expectation relates to the
ratification/accession to the Convention on Supplementary Compensation for
Nuclear Damage of September 1997, which was adopted at the Diplomatic
Conference within IAEA in Vienna together with the a.m. Protocol.
We could also learn about
the tendencies concerning some Vienna Convention Countries moving toward the
Paris/Brussels Convention system. This process should be followed carefully,
specially in conjunction with: the recent political development within Europe
and the enlargement of EU (as from the 1st May 2004) by 10 (ten) new
members states; the expressed desire by many CEE countries to join the EU in
the years to come and the need to harmonize (among others) the nuclear
liability regimes within EU.
This session and the Round
Table 3. proved again its value for the lawyers, insurers, insured and
governmental and non-governmental bodies representatives and should be
preserved for future Conferences.