004 IAEA Coordinated Research Project on the Establishment of ...

5th International Symposium on Material Testing Reactors
Columbia (MO), USA 22-25 October 2012
<strong>IAEA</strong> <strong>Coordinated</strong> <strong>Research</strong> <strong>Project</strong> on the Establishment of a Material
Properties Database for Irradiated Core Structural Components for
Continued Safe Operation and Lifetime Extension of Ageing <strong>Research</strong>
Reactors
B. van der Schaaf 1 , Y. Barnea 1 , A. Zeman 3 , A. Borio di Tigliole 1 ,
P. Adelfang 1 , E. Bradley 1 , A. Shokr 2
(1) NEFW - (2) NSNI - (3) NAPC
International Atomic Energy Agency (<strong>IAEA</strong>)

Background

Organization – <strong>IAEA</strong> / RRG

PART 1:
RRS – NEFW
Programmes and Activities

SUBPROGRAMME 1.4.2 - <strong>Research</strong> Reactors(RRS/NEFW)
<strong>Project</strong> 1.4.2.1: Enhancement of utilization and applications of research reactors
• To increase cooperation between different research reactor centres, promote networking and ‘regional
centres of excellence, both for RR host and non-host Member States
• To enhance research reactor utilization in Member States for many practical applications, such as
isotope production, neutron radiography, neutron beam research, analytical services, material
characterization and testing consistent with research reactor features, nuclear education and training
for both genders.
<strong>Project</strong> 1.4.2.2: <strong>Research</strong> reactor infrastructure, planning, and innovation
To increase the competence of interested Member States to plan and implement large scale research
reactor modernization and refurbishment projects including the construction of major research
reactor systems, new national or regional research reactors and implementation of innovative
systems, structures and components to satisfy evolving demands for research reactor goods and
services
<strong>Project</strong> 1.4.2.3: Addressing research reactor fuel cycle issues
To strengthen the capability of interested Member States having research reactors to deal with all
fuel cycle issues including fuel development, fabrication and qualification, mitigation of identified
health, safety and environmental vulnerabilities associated with spent fuel management; and to
promote conversion from HEU to LEU, repatriation of spent fuel to its country of origin, and
regional solutions to the back end of the fuel cycle.
<strong>Project</strong> 1.4.2.4: <strong>Research</strong> reactor operation and maintenance
To increase the competence of interested Member States to develop and implement operations
and/or maintenance plans including, for example, ageing management plans, integrated
management systems, and programmes to optimize facility availability and reliability.

Examples of Activities

Key issues and challenges for RR
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
0
Steady thermal
power (MW)
15936
Steady thermal power
No of reactors
1061
159
2336
302
3139
367
4401
352
354
3970
335
3741
3599306
2929265
2741237 2761236
1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010
Year
Number of
reactors
234
2187
400
350
300
250
200
150
100
50
0
Status Developed Countries Developing Countries All Countries
Operational 145 84 229
Temporary shutdown 9 6 15
Under construction 3 1 4
Planned 1 3 4
Shut down 111 22 133
Decommissioned 290 23 313
Cancelled 1 4 5
Total 560 143 703

Key issues and challenges for RR
RR underutilization
Ageing & needs for refurbishment
Fuel cycle issues
Requests for new RRs
Safety & security
…
60
Fraction of all RRs, %
50
40
30
20
10
Utilisation rate
0
high, >20FPW/year medium small,

PART 2:
Ageing of the RR fleet -
a permanent concern

The ‘Bathtub Curve’ TOLL

Radiation Damage & Ageing Mechanisms
1) Ageing is degradation of original properties (from MICRO to MACRO) due
multiple mechanisms (radiation, temperature, chemistry, etc…).
2) RR Structural Materials should be properly selected at the design
stage, maintained and aged managed.
3) RR Structural materials are characterized as follows:
a) Safety – category of component (I/II).
b) Design – replaceable (i.e., vessel)/irreplaceable (core grid,
internals, etc..)
4) RD&A mechanisms: embrittlement, thermal creep, swelling, cracking and
corrosion/erosion, all must be carefully predicted and monitored
5) Primary focus is on scientific justification to extend the pre-designed life
service.

RR Ageing Management Programmes
Database
RR Ageing Database (2009/2011) > 170 submittals
<strong>IAEA</strong>
Meetings
Biannual TM – RR Ageing, Modernization and Refurbishment (NE and NS)
~ 50 participants from >30 Member States
Operators, regulators, vendors, independent authorities

Core Components ageing – Program Outline
Survey (on going) and CRP Proposal (to be started)

Survey Questionnaire
In order to evaluate the interest in the CRP and to collect preliminary
information on the data needs and types of activities considering the
prediction of ageing related degradation of core components, the <strong>IAEA</strong>
has made available to Member States (in RRS/NEFW web-page) a
questionnaire containing the following five questions:
1. What are the components and materials affected by ageing in
your facility?
2. What information is available to you for those materials?
3. What information is not available that you would like to have?
4. What form of Database would be most useful to you?
5. What specific monitoring and surveillance programs are
implemented at your facility to address ageing of core
components and materials?

SURVEY on RR Irr. Core Materials Data-Base
http://www.iaea.org/OurWork/ST/NE/NEFW/Technical_Areas/RRS/operation-maintenance.html

Data needed for the evaluation of material
capability to perform its safety function

Data needed for the evaluation of material
capability to perform its safety function

Listing of typical research reactor core components and
structures and the most common materials used
Components that are generally fixed
and difficult to replace are indicated
by (1) and those that are more
readily replaced are indicated by (2).

Listing of typical research reactor core components and
structures and the most common materials used
Components that are generally fixed and difficult to replace are indicated by (1) and
those that are more readily replaced are indicated by (2).

Analysis of the Responses
to the CRP Questionnaire
At the present, 15 (14) Member States have provided answers in 20
(19) filled out questionnaires
Nr Member State Organization
1 Belgium SCK-CEN
2 China China Institute of Atomic ENERGY
3A Egypt Egyptian Atomic Energy Authority
3B Egypt Lecturer
4 Hungary Atomic Energy <strong>Research</strong> Institute
5A India Bhabha Atomic <strong>Research</strong> Centre
5B India Indira Gandhi Centre for Atomic <strong>Research</strong>
6 Indonesia National Nuclear Energy Agency of Indonesia
7 Malaysia Malaysian Nuclear Agency
8 Morocco CNESTEN
9 Poland National Centre for Nuclear <strong>Research</strong>
10 Russian Federation State Scientific Centre - <strong>Research</strong> Institute of Atomic Reactor
11 South-Africa NECSA
12 South-Korea KAERI
13A The Netherlands Reactor Institute Delft
13B The Netherlands NRG, Petten
14A USA Colorado School of Mines
14B USA URS Corporation
14C USA Bechtel/TVA
15 Argentina Comision Nacional de l'Energia Atomica

Question #1: Components and Materials Affected by Ageing
Number of reactions Components
12 Core basket and grid (plate support) structure
11 Reactor vessel (tank) and connecting pipes
9 Irradiation facilities
8 Control rod absorbers, followers, guide tubes safety
7 Reflector (elements)
7 None
6 Pool cooling piping and support
3 Beam ports/nozzles
3 Cooling piping and support
3 Pool liners
3 Shields thermal (carbon steel)
2 Bolts
2 Buildings
2 Column thermal and thermalizing
2 Fuel elements
1
Accumulators, Electronic components related to
Instrumentation, Fittings,
Inlet plenum, Neutron chambers, Power monitoring channel
Pressure tubes of irradiation rigs, Vault

Question #1: Components and Materials Affected by Ageing
Number of
reactions
Materials affected by ageing
9
8
5 Beryllium
4 None
Aluminium AISI 1100, 2014(T6), 5052, 6061 (T6), 6082, alloys, high
purity
Stainless steel (AISI 304L, 316, 316L, 321, 347) , Fe-18Cr-10Ni-Ti,
Fe-18Cr-9Ni
3 Zircaloy, Zircaloy-4 (R60804), zirconium alloys
3 Concrete
3 Graphite
2 carbon steel
1 Boron carbide, Coating, unspecified

Question #2: Available Information on Materials
The responses on available materials information allow categorizing the
answers into five information domains:
Materials properties
Neutron transport analysis and measurements
Operational information
Visual records and geometrical data
Documentation
The three latter information domains do not lend themselves easily for use
in other research reactors since are rather specific.
The information domains on Materials properties and Neutron transport
analysis and measurements have highly useful elements for wider
application, but more details are needed as: the temperature domain and
the accumulated radiation dose/neutron fluence the materials were
exposed to.

Question #3: Lacking Information that is needed
The responses on lacking information allow categorizing the answers into five
domains:
Radiation effects on mechanical properties
Radiation related corrosion data
Dimensional stability
Optical examination
Miscellaneous
More than half of the respondents’ reactions on lacking information have to do with
radiation effects data.
The MS identified detail areas related to the effect of radiation on mechanical
properties. With the exception of Hafnium absorbers all identified materials are
included in the listing of typical research reactor core components and structures

Question #3: Lacking Information that is needed
DATA needed
Radiation effects on
mechanical
properties
DATA DETAILS
1.Long term irradiation behaviour of Hf absorbers in MTR conditions
2.The maximum radiation (dpa) level permitted / attained for core
support structures like grid plate made from SS 316
3.Fatigue data on irradiated aluminum alloys
4. Fracture toughness data at high fluences with different thermal to
fast ratios for the same aluminium alloy
5.Irradiated material mechanical properties: tensile, toughnees, fatigue
6. Detailed microstructural changes: precipitation morphology,
composition and number density
7.Degradation evaluation of irradiation-embrittled Zircaloy-4
8.Creep and growth characteristic of Zr-4 under neutron irradiation
9.Critical integrated neutron flux with energies for the materials used

Question #4: Preferences for Database Form
Twelve Member States indicated at least MS Excel, seven mentioned at
least MS Access, and SQL was mentioned three times. The preference of
the Member States for MS Excel as Database form is evident.
The RR Operators have wide experience with the use of Excel sheets with
its simple handling and short training time for the user. MS Access needs
more knowledge and experience to handle properly. SQL requires
professional levels of knowledge and experience to use it effectively, which
raises barriers for immediate deployment for most of the RR Operators. In
return SQL offers more safeguards for the integrity of the Databases.

Question #5: Implemented Monitoring and Surveillance
Programs
The responses on implemented monitoring and survelliance programs
allow categorizing the answers into five domains:
Visual Inspection
Measurements
Dimensions
Neutron transport
Data collection & analyses
The contributing MS identified the Visual Inspection domain as the largest
category out of the major five (13 responses). This domain is not within
the Database scope

Question #5: Implemented Monitoring and Surveillance
Programs
The domain Measurements (with 8 responses) includes three answers
referring to measurement of radiation embrittlement of structural alloys.
Another three answers concern water chemistry measurements, which are
out of the scope of this CRP. The remaining two answers address
measurements of safety rod dropping, and NDT inspection. The
measurements domain has thus a rather wide range, where only the three
measurements of radiation embrittlement fall within the scope of the data
base collection and building.
The Dimension measurements have been gathered in a dedicated domain
resulting in eight items. These are of high importance for the support of
safe research reactor operation, but with exception of the swelling
measurement of control rod materials not useful for the Database.

Question #5: Implemented Monitoring and Surveillance
Programs
The domains Neutron transport and Data collection & analyses hold
respectively three and two reactions of MS. These are not contributing
directly to the data base
The Monitoring and surveillance department of the questionnaire provides
thus elements in principle valuable for the data base in the domains of :
Measurement of radiation embrittlement of structural alloys
Swelling measurement of control rod materials
Development of appropriate ageing indicators.

CONCLUSIONS
The population of research reactors was covered in a satisfying power range
above 1 MW. The number of received questionnaires, 19 (20) from 14 (15)
MS, does not allow quantitative reliable statistics. Though not all the responses
of the MS are strictly within the scope of the questionnaire, the results are
highly valuable for the identification of items relevant for the establishment of
a material properties Database for irradiated core structural components for
continued safe operation and lifetime extension of ageing RR’s.
The respondents considered the core basket and grid (plate support) structure,
reactor vessel and some irradiation facilities as the most important components
affected by ageing. Control rod related structures, reflectors and pool related
structures were mentioned less frequently.
As the major materials affected by ageing were identified stainless steel and
aluminum alloys, followed by Beryllium, carbon steel, Zircaloy and boron
carbide.

CONCLUSIONS
The information on materials properties and neutron transport
analysis and measurements have highly useful elements for wider
application into the Database. Regarding the other domains the
respondents indicate that they are too specific for inclusion into
the Database.
The most important lacking information that the respondents
indicate as needed, concerns irradiation effects on mechanical
properties. The identified materials and components are in the
listing of typical research reactor core components and structures.
For what concern the Database form, the respondents’ majority
shows a preference for MS Excel environment.

CONCLUSIONS
The monitoring and surveillance programmes implemented by the
respondents are focused on visual inspections and measurements.
Many of those are highly specific, and the resulting data are only
usable for other RR Operators after transformation of the
information into quantities lending themselves to inclusion in the
Database.
The measurement results of radiation embrittlement of structural
alloys, swelling measurement of control rod materials, and
development of appropriate ageing indicators are items that might
be included in the data base useful for a much wider community

CONCLUSIONS
Any other comment, remark and feedback
is welcomed ...
Thanks for the Attention!
Contact: A.Borio@iaea.org