COMMISSION STAFF WORKING DOCUMENT Accompanying the document Report of the Commission to the Council and the European Parliament 'Operation of the High Flux Reactor in the period 2012-13'
Date: 2016-04-05
Institutions: European Commission, Joint Research Centre
Subjects: EU research policy, Netherlands, North Holland, nuclear reactor, nuclear research, nuclear safety, nuclear technology, research programme

EUROPEAN 
COMMISSION 

Brussels, 5.4.2016  
SWD(2016) 101 final 

COMMISSION STAFF WORKING DOCUMENT 
Accompanying the document 

Report of the Commission to the Council and the European Parliament 'Operation of 
the High Flux Reactor in the period 2012-13' 

{COM(2016) 170 final} 

EN 

   EN 

 
 
 
 
  
 
COMMISSION STAFF WORKING DOCUMENT 

Accompanying the Report of the Commission to the Council and the European 
Parliament  ‘Operation of the High Flux Reactor in the period 2012-13’ 

This  staff  working  document  is  a  companion  document  to  the  Commission’s  report  on 
‘Operation of the high flux reactor in the years 2012-13’, sent to the Council and the European 
Parliament. 

The  High  Flux  Reactor  (HFR),  located  in  Petten  (The  Netherlands),  is  one  of  the  most 
powerful  multi-purpose  materials-testing  reactors  in  the  world.  The  reactor  is  of  the  tank-in-
pool type, light water cooled, moderated and operated at 45 MW. In operation since 1961, the 
reactor provides a variety of irradiation location possibilities (reactor core, reflector region and 
in  the  poolside).  Horizontal  beam  tubes  are  available  for  research  with  neutrons  as  well  as 
gamma irradiation facilities. Furthermore, fully equipped on-site hot cell laboratories make it 
possible to carry out post irradiation examinations (PIEs). 

The  European  Atomic  Energy  Community  (Euratom)  owns  the  plant  (leased  from  the  Dutch 
state  for  99  years).  The  HFR  is  owned  by  the  European  Commission  and  is  operated  by  the 
Nuclear Research and Consultancy Group (NRG). The close cooperation between the JRC and 
the NRG has led to a unique system of managing the HFR, involving both organisations.   

As of February 2005, the NRG has become the holder of the operation licence granted under 
the Dutch Nuclear Energy Law. 

Over  the  last  three  decades,  the  HFR  has  been  operated  and  partly  financed  through 
supplementary  research  programmes  which  were  regularly  discussed  and  unanimously 
approved  by  the  European  Council  on  the  basis  of  Article  7  of  Euratom  Treaty.  On  13 
November  2012,  the  Council  adopted  a  four-year  (2012-15)  supplementary  research 
programme for the HFR (Council Decision 2012/709/Euratom — OJ L321/59, 20.12.2012), to 
be implemented by the Joint Research Centre (JRC). 

This document reports on the results of the scientific and technical work carried out in 2012-
13.  It  also  provides  information  on  the  financial  contributions  received  for  implementing  the 
programme  and  the  annual  contribution  to  the  decommissioning  fund  provided  by  the 
supplementary research programme. 

1. 

HFR: REACTOR MANAGEMENT 

The  HFR’s  operating  licence  for  the  reporting  period  was  granted  by  the  Dutch  national 
regulator, the Kernfysische Dienst. 

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1.1. 

HFR safety, operation and related services 

Operating schedule 

2012 

In 2012, the planned cycle pattern consisted of a scheduled number of 296 operation days and 
one maintenance period of 31 days in March. The in-service inspection of the north and south 
reducer, welds of  the reactor  vessel and the annual  leak test of the reactor containment were 
performed during this period. In reality, the HFR was in operation 253 days (or 6090:57 min — 
Table 1). This corresponds to an actual availability of 85.26 %, as compared with the original 
schedule.  Its  nominal  power  was  at  45  MW,  and  the  total  energy  production  for  2012  was 
approximately  11 313  MWd,  corresponding  to  a  fuel  consumption  of  about  14.12  kg  U-235. 
The 30-day planned cycles 2012-10 and 2012-11 were cancelled. One of the reasons for this 
was the detection of tritium in the groundwater around the reactor building, which was traced 
back to an underground leak in a water pipeline. The other reason was the detection of a leak 
path between the primary cooling water system and the bottom plug cooling system (part of the 
pool  cooling  system).  Both  issues  were  independent  were  investigated  and  repaired  and  the 
reactor was restarted safely. 

Figure 2 shows the total discharged activity of tritium and noble gases in 2012 compared with 
values since 1999. The license limit is 100 RE/year. The total discharged activity in 2012 was 
approximately 11 RE (Note: RE: amount of radioactivity causing a dose of 1 Sv if inhaled or 
ingested) 

2013 
In 2013, the planned cycle pattern consisted of a scheduled number of 166 operation days and 
a  maintenance  period  of  18  days  during  the  month  of  August.  During  the  repair  and 
maintenance  period  between  1  January  2013  and  10  June  2013,  the  tritium  level  which 
appeared  in  the  groundwater  around  the  reactor  building  decreased.  A  small  cooling  water 
leak  from  the  basin  cooling  water  system  to  the  primary  cooling  water  system,  caused  by  a 
broken  seal  in  the  bottom  plug  liner,  was  repaired  by  installing  a  second  seal  and  leak 
detection system.,  
The planned cycles 2013-04, 2013-05 and 2013-06 were cancelled due to problems with the 
structural  integrity  of  three  control  rods.  The  problem  was  investigated  during  an  extended 
root cause analysis. The reactor, meeting all safety requirements, was authorised by KFD to 
returnto service at the beginning of 2014. 

During the year, the HFR was in operation during about 81 days (or 1956:49 min — Table 2). 
This corresponds to an actual availability of 49.07 %, as compared with the original schedule. 
Its nominal power was 45 MW, and the total  energy production in 2013 was  approximately 
3661 MWd, corresponding to a fuel consumption of about 4.57 kg U-235. 

3 

 
 
 
 
Table 1: Summary of HFR operation in 2012 

Table 2: Summary of HFR operation in 2013 

Figure 1: HFR availability since 2003 

Figure 2: Radioactivity (noble gas and tritium) emitted since 1999 

Maintenance activities 

2012 and 2013 

4 

 
 
 
 
 
 
In  2012  and  2013,  maintenance  activities  consisted  of  the  preventive,  corrective  and 
breakdown  maintenance  of  all  systems,  structures  and  components  (SSC)  of  the  HFR,  as 
described in the annual and long-term maintenance plans. These activities were carried out to 
ensure  the  HFR’s  safe  and  reliable  operation  and  to  prevent  inadvertent  scrams  caused  by 
insufficient maintenance. 

The main activities carried out during the maintenance period were the following: 

• 

Periodic  leak  test  of  the  containment  building,  as  one  of  the  licence  requirements 
(0.05 MPa overpressure for 48 h) — 2012. 

Periodic leak test  of the containment  building, as one of the licence requirements  (0.02 MPa 

overpressure for 24 h) — 2013. 

The in-service inspection of the north and south reducers and the welds of the reactor vessel. 

The in-service inspection of a part of the primary system in the primary pump building. 

Regular repair maintenance of the concrete pipeline for secondary cooling water between the 

North-Holland Canal and the HFR secondary pump building. 

Extension of the secondary outlet pipeline further into the North Sea. 

Completion  of  the  remote  monitoring  system  which  is  used  to  monitor  important  reactor 

parameters during emergency cases. 

Completion  of  the  alternative  shutdown  system  which  can  be  used  if  the  normal  shutdown 

system is not functioning. 

These activities were successfully completed. 

5 

 
 
 
HFR AS A TOOL FOR RESEARCH ON REACTOR MATERIALS AND FUEL CYCLES 

1.1. 

Towards  a  fuel  cycle  with 
PELGRIMM projects 

less  nuclear  waste:  the  FAIRFUELS  AND 

The two closely linked 4-year projects FAIRFUELS (fabrication, irradiation and reprocessing 
of  fuels  and  targets  for  transmutation,  and  PELGRIMM  (pellets  vs  granulates:  irradiation, 
manufacturing  and  modelling)  run  under  the  EURATOM  7th  Framework  Programme  (FP7) 
indirect  actions.  They  aim  at  a  more  efficient  use  of  fissile  material  in  nuclear  reactors  by 
implementing transmutation. Transmutation provides a way to reduce the volume and hazard 
of  high-level  radioactive  waste  by  recycling and  converting  the  most  long-lived  components 
into  shorter-lived  species.  In  this  way,  the  nuclear  fuel  cycle  can  be  closed  in  a  sustainable 
way, producing less and shorter-lived radioactive waste. 
The  FAIRFUELS  consortium  consists  of  10  European  research  institutes,  universities  and 
industry  representatives.  The  project  started  in  2009  and  is  coordinated  by  the  NRG.  The 
PELGRIMM consortium consists of 12 European research institutes, universities and industry 
representatives.  The  project  started  in  2012  and  is  coordinated  by  the  Centre  d'Etudes 
Atomiques (CEA), France. 
The NRG and the JRC work closely together on the HFR irradiations that are scheduled as part 
of the FAIRFUELS and PELGRIMM projects. 

MARIOS 

Part  of  the  FAIRFUELS  project,  MARIOS  is  an  irradiation  test  dealing  with  heterogeneous 
recycling of minor actinides (MAs) in sodium-cooled fast reactors. MAs, such as americium 
and curium, are long-lived radioactive isotopes in high-level nuclear waste, and are currently 
not recycled. The aim of MARIOS is to investigate more closely the behaviour of MA targets 
in a uranium oxide matrix and to compare dense fuel to fuel with a tailored porosity. In these 
targets,  large  amounts  of  helium  are  produced  and  cause  swelling  and  significant  damage  to 
the  material  under  irradiation.  It  is  the  first  time  that  americium  (241Am)  is  included  in  a 
(natural)  uranium  oxide  matrix  to  conduct  an  experiment  to  assess  helium  production  and 
swelling. 
The MARIOS irradiation started on 19 March 2011 and successfully finished on 2 May 2012 
after  11  reactor  cycles  (~304  full  power  days).  The  irradiation  was  completed  and 
disassembled in the NRG hot cells in Petten and was ready for PIE in 2013. Pellet integrity, 
helium and fission gas release and results from gamma scans were reported for pellets of two 
different  densities  irradiated  at  well-defined  temperatures.  The  pellets  were  allowed  to  swell 
freely during irradiation. Helium production (characteristic for americium containing fuel) and 
fuel burn-up were determined using calibrated post-irradiation calculations. 
The fuel with tailored porosity behaved like the less porous fuel. A ~100 % helium release was 
observed for all four capsules, showing that the threshold for high helium release lies below 
1000 °C. Finally, dismantling one of the four fuel pins revealed that five out of six pellets had 
broken into two parts of about equal size. This was probably due to thermal stresses built up 
during irradiation. 

SPHERE 

The SPHERE irradiation test was planned under the FP7 FAIRFUELS project. SPHERE was 
designed  to  compare  conventional  pellet-type  fuels  with  so-called  sphere-pac  fuels  under 
similar irradiation conditions. The latter have the advantage of an easier, dust free production 

6 

 
 
process. Especially when dealing with highly radioactive minor actinides, dust-free production 
processes are essential to reducing the risk of contamination. 
To assess the irradiation performance of sphere-pac fuels compared with conventional pellet 
fuel, an americium-containing driver fuel for fast reactors (both in pellet- and sphere-pac form) 
was produced at the JRC in Germany. These fuels are irradiated in the HFR, in a dedicated test 
facility. This is the first irradiation test of this kind, as americium-bearing sphere-pac driving 
fuel has never been irradiated before. 
In 2012, SPHERE’s design was finalised; the fuel was produced by JRC and delivered to NRG 
in  the  summer  of  2012.  The  production,  assembly  and  commissioning  of  the  irradiation 
experiment  was  completed  so  that  SPHERE  was  ready  for  irradiation  as  soon  as  the  HFR 
would resume operation. The SPHERE irradiation started on 28 August 2013 in the HFR core 
and lasted for approximately 300 full power days. The temperatures obtained were in line with 
predictions  and  target  values.  In  2013,  a  pre-irradiation  neutron  radiograph  was  taken,  to  be 
compared  with  a  neutron  radiograph  after  the  first  cycle.  This  made  it  possible  to  verify  the 
expected  fuel  restructuring  in  the  sphere-pac.  The  first  irradiation  cycle  was  completed  in 
2013. 
HELIOS 
The  HELIOS  irradiation  was  performed  as  part  of  the  terminated  FP6  EUROTRANS 
integrated project on partitioning and transmutation (2005-10) and dealt with the irradiation of 
U-free inert matrix fuels containing americium with the objective of incinerating this MA. The 
main  objective  of  the  HELIOS  irradiation  was  to  assess  the  in-pile  behaviour  of  ceramic 
matrices  and  metallic  matrix  fuel  targets  in  order  to  gain  knowledge  about  the  role  of 
microstructure and temperature on helium gas release and fuel swelling. During the irradiation 
of  such  fuel,  a  significant  amount  of  helium  is  produced  due  to  the  transmutation  of 
americium.  Understanding 
the 
transmutation yield and to achieving an optimum performance for these fuels. Two different 
approaches were followed to reach early helium release and thus to keep fuel damage low: 

the  gas  release  mechanisms 

to  maximising 

is  vital 

(1) 

Providing release paths for helium to plenum gas by creating open porosity in the fuel. 
Therefore,  a  composite  target  with  an  MgO  matrix  containing  a  network  of  open 
porosity was included in the HELIOS test plan. 

Increasing  the  target  temperature  in  order  to  promote  the  release  of  helium  from  the  matrix. 
Americium-  or  americium/plutonium-zirconia-based  solid  solutions  and  CerMet 
targets were included in the test plan to investigate the effects of temperature. 

Post-irradiation examination (PIE) of irradiated HELIOS fuel was planned as part of the FP7 
FAIRFUELS project. 
In 2012, the post-irradiation examination of  NRG  hot cells was finalised. All five pins were 
punctured  to  analyse  the  gas  pressure  (to  determine  the  helium  release  fraction)  and  the 
isotopic distribution in the fuel. Destructive PIE was performed in collaboration with the CEA. 
The pin with an MgO matrix was to be examined by the CEA but transport issues prohibited 
this. The CEA therefore visited the NRG to perform the examination together. The pin showed 
very  stable  behaviour  where  the  increased  porosity  stimulated  the  release  of  fission  gas 
(around 43% of it) most of which was helium. The swelling of the pellets was acceptable, with 
a volumetric swelling of less than 3 % for a burn up of 5.11 %. 
For the pins containing molybdenum matrix fuel, optical microscopy and SEM examinations 
were performed at the NRG. For these pins, there was a clear temperature effect. Although the 
pin irradiated at roughly 500 °C showed very stable behaviour, almost no swelling and limited 

7 

 
 
gas  release,  the  pin  at  a  high  temperature  (up  to  1200 °C)  showed  the  opposite.  Although 
helium gas release was measured as relatively high, it was insufficient to avoid significant fuel 
swelling, and pellet-cladding interaction therefore occurred. 

MARINE 

MARINE  is  planned  as  part  of  the  FP7  PELGRIMM  project.  MARINE  was  designed  to 
compare  conventional  pellet-type  fuels  with  the  so-called  sphere-pac  fuels  described 
previously. The goal of the MARINE irradiation is to determine helium release behaviour and 
fuel  swelling  in  an  element  which  is  representative  of  the  minor  actinide-bearing  blanket 
material to be used for transmutation in sodium fast reactors (SFR). 
Americium-containing  fuels  will  be  produced  at  the  JRC  and  they  will  be  irradiated  at  the 
HFR in a dedicated test facility. The irradiation will use internal pressure sensors to monitor 
online the production of helium, which is characteristic of this kind of americium-containing 
fuel. The MARINE irradiation is expected to start in early 2015 and will last for approximately 
300 full power days. 
In  2012-13,  the  design  of  MARINE  was  finalised  with  the  development  of  a  new  system  to 
connect the pressure transducer (produced in Halden) with the fuel pins (produced at the JRC). 
Safe  connection  and  transportation  of  the  fuel  pins  with  the  pressure  transducers  will  be 
managed  in  Petten  with  the  use  of  burst  discs  sealing  the  fuel  pins.  After  connection  of  the 
pressure  lines  in  Petten,  the  burst  discs  will  be  intentionally  broken  to  allow  gas  to  freely 
expand from the pins to the pressure transducers. Preliminary nuclear and thermo-mechanical 
assessments  have  been  performed  and  led  to  the  decision  to  irradiate  the  experiment  in  a 
specific  position  of  the  HTR  where  the  blankets  of  an  SFR  (power,  temperature,  helium 
production) can be reproduced as closely as possible. 

1.2. 

Fuel and graphite qualification for high-temperature reactors 

High-temperature  reactors  (HTRs)  are  being  investigated  in  a  number  of  countries  as  a  safe 
and efficient source of energy, in particular for the cogeneration of industrial process heat and 
electricity.  Related  new  demonstration  projects  are  either  in  place  or  planned  in  several 
countries  (e.g.  Japan,  China,  US,  South  Korea)  and  are  the  subject  of  current  R&D  being 
carried out in Europe. The HFR is used in particular for the qualification of fuel and graphite 
which are key to ensuring that this type of reactor performs safely. 
HFR-INET 
Based on experience related to the German HTR programme in the 1980s, in which the HFR 
had played a crucial role, a licensing strategy was developed and includes: (1) fuel irradiation 
at  specific  temperatures  to  a  specific  burn-up  target  and  (2)  successive  heating  tests  of  the 
irradiated fuel under simulated accident conditions. For the fuel to be considered acceptable in 
both  types  of  tests,  the  measured  fractional  release  of  fission  gas  must  remain  below  the 
licensing thresholds. 
The Institute of Nuclear and New Energy Technology (INET) of the Tsinghua University in 
Beijing,  China  is  currently  building  the  Chinese  Modular  High  Temperature  Gas-cooled 
Reactor Demonstration Plant (HTR-PM). The fuel for HTR-PM is produced by INET. INET 
requires  qualification  of  their  fuel  to  support  the  licensing  of  HTR-  PM.  The  HFR-INET 
irradiation  is  the  first  step  in  the  HTR  fuel  qualification  process  for  HTR-PM  and  is  being 
carried out by the NRG. 
Five spherical HTR fuel elements (‘pebbles’) are irradiated under controlled conditions in the 
HFR,  at  almost  constant  central  pebble  temperature,  while  fission  gas  release  is  measured 

8 

 
 
continuously online using the sweep loop facility. This sweep loop facility was developed and 
in the past used by the JRC and is currently being used by the NRG. It makes it possible to 
control  the  temperature  of  the  fuel  elements  and  to  monitor  fission  gas  release  during 
irradiation  by  gamma  spectrometry.  Fission  gas  release  is  an  important  measure  for  fuel 
performance and quality under operational conditions, and forms an essential part of the fuel 
qualification process. A dedicated irradiation test facility was designed and produced for the 
qualification irradiation process. 
The  irradiation  started  in  September  2012  in  a  high  flux  in-core  position  of  the  HFR  and 
continued  in  2013.  It  will  continue  to  2014-15,  until  the  required  burn-up  level  is  achieved. 
After irradiation, non-destructive PIE will be performed in the NRG hot cells. 
For the second step of the fuel qualification process, the five HTR pebbles are subjected to a 
heating test at the JRC in Karlsruhe in Germany, in the so-called KÜFA-facility. The heating 
test  is  to  demonstrate  the  integrity  and  proper  performance  of  irradiated  HTR  fuel  under 
accident conditions. 
INNOGRAPH-1C 
Graphite is used as a moderator and reflector material in an HTR and is known to first shrink 
and  then  swell  under  irradiation.  This  behaviour  depends  on  temperature,  neutron  dose  and 
graphite grades. An understanding of graphite is required for the proper design of HTRs and to 
enable  the  graphite  manufacturing  industry  to  produce  suitable  graphite  grades  with  stable 
properties over longer periods of time. 
The INNOGRAPH-1C irradiation is performed as part of the FP7 ARCHER project (advanced 
high-temperature  reactors  for  cogeneration  of  heat  and  electricity  R&D).  It  follows  earlier 
irradiation tests (cf. Figure 7), and will complete the data set for different graphite grades at 
various temperatures, under a range of neutron doses. The experiment is a technical building 
block for nuclear cogeneration using HTRs as an alternative to fossil fuels. 
The  experiment  was  successfully  commissioned  for  irradiation  in  2012.  The  irradiation  of 
three HFR cycles were completed in September 2013, with dismantling completed and the first 
PIE measurements carried out by the end of 2013. Measurements continued until mid-2014. 

1.3.  Materials irradiation 

BLACKSTONE 
The United Kingdom’s EdF Energy operates a fleet of advanced gas cooled reactors (AGRs). 
Graphite  degradation  is  considered  to  be  one  of  the  key  issues  that  determine  the  remaining 
service life of an AGR. Data on graphite’s behaviour at high irradiation doses and weight loss 
is  required  to  make  it  possible  to  predict  and  assess  the  behaviour  of  AGR  graphite  cores 
beyond their currently estimated lifetimes, thus ensuring continued safe operation and lifetime 
extension.  The  BLACKSTONE  irradiations  use  samples  trepanned  from  AGR  core  graphite 
and  subjects  them  to  accelerated  degradation  in  the  HFR.  The  tests  are  designed  to  make  it 
possible to predict the future condition of the AGR graphite with confidence. 
After phase I of BLACKSTONE, which finished in 2012, EdF Energy have successfully used 
this  data  to  support  an  updated  safety  case  for  their  AGR  power  stations,  following  an 
evaluation of the data and methods used by the UK nuclear regulator. In the meantime, phase 
II was also completed, with the irradiation of the two capsules for 12 and 16 irradiation cycles. 
The  first  capsule  was  dismantled  in  late  2012,  with  measurements  being  taken  throughout 
2013. The second capsule was dismantled in February 2014, with measurements being taken 
until October 2014. 

9 

 
 
The  ACCENT  irradiations  also  use  samples  trepanned  from  AGR  core  graphite  and  apply 
pressure to the sample during irradiation. These tests aim to predict microscopic variation in 
the size of the material, to make it possible to predict the future condition of the AGR graphite 
with confidence. 
Phase  I  of  ACCENT  began  at  the  very  end  of  2012,  with  the  design  and  construction 
completed  in  time  for  the  first  irradiation  of  one  HFR  cycle  in  the  summer  of  2013.  The 
sample  was  dismantled  and  measurements  completed  in  the  autumn  of  2013.  Following  the 
success of phase I,pPhase II began an irradiation of an estimated six HFR cycles in February 
2014, with measurements completed by December 2014. 
LYRA-10 
The LYRA irradiation rig is used in the framework of the European AMES (Ageing Materials 
and Evaluation Studies) network activities with the main goal of understanding the irradiation 
behaviour of reactor pressure vessel (RPV) steels, thermal annealing efficiency and sensitivity 
to re-irradiation damage. The LYRA-10 experiment carried out in the pool side facility of the 
HFR consists of the irradiation of different specimen types representative of reactor pressure 
vessel materials, namely model steels, realistic welds and high-nickel welds (cf. Figure 8). The 
model steels are grouped into 12 batches with the basic, typical composition of WWER-1000 
and  PWR  reactor  pressure  vessel  materials  studied  by  the  JRC  to  understand  the  role  and 
influence  of  Nikel,  Silicon,  Chromium  and  Manganesen  as  alloying  elements  and  certain 
impurities such as Carbon and Vanadium on the mechanical properties of steels. The realistic 
welds  are  created  at  eight  different  heats,  specially  manufactured  based  on  typical  WWER-
1000 weld composition with variation of certain elements, such as Nikel, Silicon, Chromium 
and Manganese. It is important to investigate the role and synergisms of alloying elements in 
the radiation-induced degradation of RPV welds. 
The LYRA-10 irradiation campaign started in May 2007 and was interrupted due to technical 
problems  several  times;  it  has  so  far  included  six  HFR  cycles  at  an  average  temperature  of 
283 °C.  The  original  plan  included  the  irradiation  of  seven  more  cycles  to  achieve  a  fast 
fluence, but it was decided during the LYRA-10 outage that at least 10 more HFR cycles are 
required to determine whether a ‘late-blooming’ effect occurs in the irradiated materials. ‘Late 
blooming’ is a possibly increased effect on material properties at higher irradiation doses, e.g. 
a  stronger  decrease  of  ductile-to-brittle  transition  temperature  in  materials  which  would  not 
match currently used correlations. 
In  order  to  proceed  with  the  resumption  of  the  LYRA-10  experiment,  a  number  of  actions 
were carried out in 2012 to make the rig fit for irradiation. The experiment should have started 
at  the  end  of  2012  but  due  to  the  HFR  shutdown,  it  was  delayed  into  2013.  In  2013,  it  was 
irradiated  for  two  more  cycles,  for  a  total  of eight  HFR  cycles  at  an  average  temperature  of 
283 °C. It is planned to continue the irradiation for five more cycles to achieve the fast fluence 
requested. 
However,  the  experiment  had  to  be  put  on  hold  to  repair  a  leak  in  a  gas  line  used  for 
temperature control, resumed at the end of 2014. 

1.4. 

Irradiations for fusion technology 

ITER PRIMUS 
In 2005, an experiment was defined with the members of the European Fusion Development 
Agreement  (EFDA)  to  test  thermal  fatigue  of  normal  heat  flux  modules  for  ITER  during 
irradiation. This experiment was planned to take place at the HFR pool side facility position 
for the duration of 22 cycles. It had to be designed in a way so that the stress conditions and 

10 

 
 
temperatures  would  reflect  ITER  first  wall  conditions.  Between  2005  and  2007,  multiple 
iterations and adjustments have been made to achieve the ITER conditions. These led to a final 
design in 2008, but could not continue because of an HFR outage. In 2009, the position in the 
HFR  pool  side  facility  was  not  available.  In  2010,  the  Reactor  Safety  Committee  gave  the 
feedback that the thermal cycling in the HFR was not possible due to the intrinsic design of the 
automatic control rod system.  
This issue was discussed with the Joint Undertaking 'Fusion for Energy' (hereinafter F4E) as 
EFDA ceased to exist by end of December 2013 and instead a stagnant in-pile experiment was 
proposed, to achieve 1 dpa in beryllium, and to perform the thermal cycling afterwards in the 
JUDITH facility in Jülich was proposed. 
To perform this irradiation, a new experiment called PRIMUS was designed. 
In 2012, a new conceptual design was presented by F4E and extensive activation calculations 
showed that the mock ups were too active to be handled in the JUDITH facility. Therefore, a 
proposal  was  made  to  cut  the  steel  back  from  the  mock-ups,  without  jeopardising  the  stress 
conditions on the beryllium/CuCrZr interface. 
This  led  to  a  proposal  which  reduced  the  activation  to  levels  acceptable  for  JUDITH.  The 
mock-ups were sent back to France, where the cutting procedure started. 
In 2013 the adapted first wall mock-ups were delivered by F4E. The stainless steel part on the 
back of the mock-up was reduced by 60 % to decrease the activation after irradiation. This was 
necessary to comply with the limits for activity in the JUDITH facility. New irradiation design 
calculations were performed using the new geometry, and the irradiation proposal was drafted. 
This  led  to  a  design  with  a  clamping  system  of  aluminium  blocks  to  allow  for  radial  heat 
dissipation during irradiation. The temperature on the Cu-Be interface during irradiation will 
be 225 °C and the accumulated irradiation dose after five cycles of irradiation will be 1 dpa. 
Irradiation started in 2014. 
CORONIS 
In  2011,  a  new  project  started  under  F4E,  focusing  on  ITER’s  material  development  and 
characterisation. 
The  objective  was  to  measure  the  tensile,  fatigue  and  Charpy  impact  properties  of  shielding 
blanket material and shielding blanket joints before and after irradiation to 0.01, 0.1 and 0.7 
dpa at 250 °C. This material is planned to be used in the shielding blanket in ITER because of 
its  high  heat  dissipation.  This  property  could  be  jeopardised  if  the  material  fails  during  its 
operational lifetime in ITER. 
In  2013,  the  CORONIS  01  and  CORONIS  02  experiments  were  developed,  assembled  and 
commissioned.  After  filling  with  sodium  in  the  ECN  workshop,  the  experiments  were 
transferred to the HFR for irradiation. 
CORONIS 01 will be irradiated for one cycle corresponding to 0.1 dpa. Both experiments are 
carried out at a homogeneous temperature of 250 °C.  The  materials  in  CORONIS  01  and  02 
are ones which will be used as heat sink material for ITER’s first wall shielding modules. The 
experiments started irradiation at the end of 2013. 
CORONIS  02  aims  to  accumulate  0.7  dpa  corresponding  to  a  three-cycle  irradiation  in  the 
HFR. 
All post-irradiation experiments will be performed at the NRG hot cells. The project runs from 
1 January 2011 to October 2015. 
FIWAMO 

11 

 
 
In  July  2012,  a  new  contract  was  signed  between  ITER  International  Organization, 
Forschungszentrum Jülich (FZJ) and the NRG for the irradiation and high heat flux testing of 
eight enhanced heat flux first wall modules for ITER. 
The ITER first wall is produced using two technologies, normal heat flux (NHF) for loading 
up to 2 MW/m2 and enhanced heat flux (EHF) for loading up to 5 MW/m2. The plasma-facing 
surface  of  the  first  wall  is  made  of  beryllium  tiles  that  are  joined  to  a  heat  sink  using  hot 
isostatic pressing or brazing. The heat sink is attached to a supporting steel structure. 
The scope of this project is to perform a pre-irradiation screening of the modules, from SWIPP 
(China)  and  NIIEF  (Russia),  irradiation  in  the  HFR  to  0.1  and  0.7  dpa  at  200-250 °C  and  to 
perform post irradiation high heat flux testing in the JUDITH facility at FZJ up to 5 MW/m2. 
In 2013, Phase 1 of the contract was concluded with the submission of a final design proposal 
for the irradiation capsule. 
The  mock-ups  consists  of  beryllium  tiles  that  are  joined  to  the  heat  sink  using  hot  isostatic 
pressing or brazing technology. They will be clamped between aluminium blocks to allow for 
radial heat dissipation during irradiation. The interface between the copper and beryllium will 
be held at 225 °C. The mock-ups will be irradiated to doses of 0.1 and 0.6 dpa, respectively.. 

1.5. 

HFR support for research on the standardisation of materials 

Network on Neutron Techniques Standardisation for Structural Integrity (NeT) 
The European Network on Neutron Techniques Standardisation for Structural Integrity (NeT) 
fosters performance and safety improvements in European nuclear power plants. NeT mainly 
supports progress towards improved understanding and prediction of welding residual stresses 
relevant for the integrity of nuclear power plant components. 
The JRC organises and manages NeT and contributes to the scientific work through neutron 
scattering for residual stress measurement using its beam tube facilities at the HFR. 
In 2012, NeT developed new activities on residual stresses in welds of nickel-based alloys and 
aluminium specimens. These materials are relevant for new types of dissimilar metal welds in 
nuclear piping systems and to welds in research reactor installations. 
In 2013, NeT prepared summary reports and publications on its work on a three-bead weld in 
an  austenitic  stainless  steel  plate.  This  work  is  likely  to  be  the  most  comprehensive 
experimental  and  computational  round  robin  type  investigation  on  welding  residual  stresses 
currently in existence. NeT is going to complement this work with similar activity on welding 
in  a  nickel  base  alloy.  The  specimen  design  for  this  new  activity  has  been  agreed  on  and 
specimens were available for measurements in 2014. 
Standardisation of the neutron diffraction method for residual stress measurement 
The scientific and engineering community use neutron diffraction as a technique for measuring 
residual stresses in materials and components. Work on the development of a standard for the 
method  has  been  in  progress  for  about  15  years.  The  JRC  has  been  involved  from  the 
beginning with its two dedicated  diffractometers  at  the HFR. An  ISO technical specification 
about the method was published in 2005. The activity is now entering its final phase, where 
the method’s technical specification is being upgraded to an international standard. 
In  2012,  negotiations  were  undertaken  with  the  ISO  and  several  national  neutron  beam 
facilities  in  order  to  set  up  a  working  group  that  would  thoroughly  review  the  existing 
specification.  In  2013,  a  proposal  was  submitted  to  ISO  Technical  Committee  135  on  Non-
Destructive Testing to set up a working group charged with the review of the document and 
subsequent  submission  for  adoption  as  a  full  standard.  Five  member  countries  from  three 

12 

 
 
continents agreed to participate. The working group was set up in 2014. 
PhD on neutron diffraction stress measurements in welded components performed at the HFR 
On 12 November 2013, a scientist from the JRC concluded his PhD research entitled ‘Residual 
stresses in thick bi-metallic fusion welds: a neutron diffraction study’. The neutron diffraction 
work  on  which  the  PhD  thesis  is  based  had  been  performed  using  the  HFR  residual  stress 
measurement  facilities.  The  components  investigated  were  multi-pass  fusion  welds  designed 
as scaled mock-ups of real nuclear components. The need to penetrate wall thicknesses of up 
to  51  mm  with  the  neutron  beam  pushed  the  technique  almost  to  its  limits.  The  work 
demonstrated  the  feasibility  of  such  investigations  and  presented  a  novel  approach  to  the 
assessment of the measurement uncertainty for such cases. 

ISOTOPE PRODUCTION 

Isotope  production  was  severely  affected  by  the  disruption  of  the  HFR’s  operation  between 
2012 and 2013. 
Until  mid-November  2012  when  the  HFR  was  shutdown  for  repairs,  isotope  production 
operated normally. Therfore only nine full cycles of normal isotope production were achieved 
and 1.5 cycles of production were lost. 
Until the HFR shutdown for repairs, the value of isotopes and associated services supplied was 
higher  than  in  the  preceding  year.  A  number  of  interesting  new  product  development  ideas 
continued  to  progress,  both  in  conventional  application  areas  and  in  some  ground-breaking 
areas of medical technology. For example, neutron transmutation doped (NTD) silicon came 
back  into  production.  NTD  silicon  products  can  be  found  in  important  applications  such  as 
high-voltage power electronics, high-speed trains, and green technologies, e.g. wind, solar and 
hybrid cars. 
A severely disrupted year of operation for isotope production was experienced at the HFR in 
2013,  with  only  around  49 %  of  the  normal  operating  schedule  available.  Nevertheless,  the 
HFR  still  performed  an  important  role  in  ensuring  the  supply  of  vital  medical  isotopes  and 
other industrial isotopes in Europe during a period when other research reactors were out of 
operation. 
The  HFR’s  outages  reinforced  the  need  to  support  the  coordinated  efforts  necessary  to 
minimise the future risks to the security of supply of critical medical isotopes. The NRG fully 
supports the recommendations of the OECD/NEA High Level Group on the security of supply 
of  medical  isotopes.  It  continued  to  work  closely  with  other  actors  in  the  medical  isotope 
supply  network,  as  well  as  with  the  medical  community,  governments,  the  European 
Commission,  AIPES,  and  the  IAEA  on  important  issues  such  as  full-cost  recovery  pricing, 
outage  reserved  capacity  provision,  future  infrastructure  investment  and  conversion  to  low 
enriched uranium targets for Mo-99 production. 

13 

 
 
 
FINANCIAL CONTRIBUTIONS TO THE PROGRAMME’S IMPLEMENTATION 

In 2012-13, the following financial contributions were received from Member States for the 
implementation of the supplementary programme: 

• 

Belgium: EUR 300 000 (2012) + EUR 300 000 (2013), 

France: EUR 300 000 (2012) + EUR 300 000 (2013), 

The Netherlands: EUR 7 250 000 (2012) + EUR 7 250 000 (2013), 

for  a  total  of  EUR  15 700 000.  Note  that  these  contributions  cover  the  expenses  specified 
under Annex II of Council Decision 2012/709/Euratom. The Commission does not cover any 
operational deficits, including potential costs of maintenance or repair. 

Since 2004, due to a re-evaluation of decommissioning costs, the annual contribution of the 
supplementary programme to the decommissioning fund increased from EUR 400 000/year to 
EUR  800 000/year.  This  amount  is  taken  from  (a)  the  regular  budget  of  the  supplementary 
research programme and (b) the interest earned on the bank account of the decommissioning 
fund of the supplementary research programme. For example, in 2013 the estimated amount 
of interest generated by the decommissioning fund was EUR 145 000. Therefore, only EUR 
655 000 was added from the regular supplementary research programme budget to reach the 
EUR 800 000/year. As of 31 December 2013, the total amount in the decommissioning fund is 
EUR 15 639 000. 

This  fund  will  contribute  to  the  future  decommissioning  costs  of  the  HFR  (to  be  borne  by 
Euratom), estimated at EUR 72 600 000 in the most recent decommissioning study available.1 

Other  expenditure  incurred  by  the  JRC  during  the  reporting  period  and  paid  from  the 
supplementary research programme budget includes: 

direct staff costs (e.g. HFR supplementary research program management): EUR 345 000 

HFR support costs (e.g. legal advice): EUR 66 000 

utilities (e.g. electricity, water, heating): EUR 993 000 

spent fuel management costs: EUR 1 902 000 

1 

from 

the  Commission 

the  European  Parliament  on 
Communication 
Decommissioning  of  Nuclear  Installations  and  Management  of  Radioactive  Waste:  Management  of 
Nuclear Liabilities arising out of the Activities of the Joint Research Centre (JRC) carried out under the 
Euratom Treaty — COM(2013) 734 final. 

the  Council  and 

to 

 
 
                                                            
Glossary and Acronyms 

AIPES 

Association of Imaging Producers and Equipment Suppliers 

ARCHER 

Advanced High-Temperature Reactors for Cogeneration of Heat and Electricity R&D 

dpa 

displacements per atom 

Euratom 

European Atomic Energy Community 

FAIRFUELS 

Fabrication, Irradiation and Reprocessing of FUELS and target for transmutation 

F4E 

HFR 

IAEA 

INET 

ISO 

ITER 

JRC 

MA 

Fusion  for  Energy  (the  European  Union’s  Joint  Undertaking  for  ITER  and  the  
development of fusion energy) 

High Flux Reactor 

International Atomic Energy Agency 

Institute for Nuclear and New Energy Technology (Tsinghua University Beijing, China) 

International Organisation for Standardisation 

International Thermonuclear Experimental Reactor 

Joint Research Centre 

Minor Actinides 

MARIOS 

Minor Actinides in Sodium-cooled Fast Reactors 

NeT 

NRG 

EU Network on Neutron Techniques Standardisation for Structural Integrity 

Nuclear Research and consultancy Group 

OECD/NEA 

Organisation for Economic Cooperation and Development / Nuclear Energy Agency 

PELGRIMM 

PELlets versus GRanulates: Irradiation, Manufacturing & Modelling 

PIE 

RE 

Post Irradiation Examination 

1 RE: amount of radioactivity causing a dose of 1 Sv if inhaled or ingested