Transnubel Experience dry storage of spent fuel Belgium ......Experience dry storage of spent fuel...
15
Transnubel Experience dry storage of spent fuel Belgium NPP Doel 20/05/2014 Xavier Van Mierloo Workshop IAEA May 2014 Experience dry storage of spent fuel Belgium 1
Transcript of Transnubel Experience dry storage of spent fuel Belgium ......Experience dry storage of spent fuel...
Transnubel
Experience dry storage of spent fuel
Belgium NPP Doel
20/05/2014
Xavier Van MierlooWorkshop IAEA May 2014
Experience dry storage of spent fuel Belgium
1
20/05/2014
Spent fuel Belgium
Introductory remarks
• Experience of dry spent fuel storage in Belgium• Presentation is for information purposes only• Spent fuel management is a cooperation of
different partners• Synatom, Electrabel, Tractebel, Transnubel
Experience dry storage of spent fuel Belgium
2
20/05/2014
Spent fuel Belgium
• Moratorium on reprocessing of Belgian spent fuel since ‘93
• Spent fuel elements of the NPPs of Tihange are stored on-site in dedicated spent fuel pools• SF is transported in a wet transfer cask from the
units to the spent fuel pool• Spent fuel elements of the NPPs of Doel are
temporary stored on-site in a dedicated building with dry dual purpose casks
• The Belgian operators are awaiting the decision of their definitive destination:• Transport followed by reprocessing• Transport followed by conditioning for final disposal
• As long as this decision is not taken, these fuel assemblies are not considered to be waste!
Experience dry storage of spent fuel Belgium
3
20/05/2014
• Storage on-site in a dedicated storage building• Storage of spent fuel in type B(U)F or B(M)F transport
casks • Transport on-site with transport license• Storage authorization is coupled to the package
approval • Problem:
• Renewal of package approval certificate is getting more difficult over time
• Maintain full conformity of loaded cask with package design could be difficult over time (small evolution in design) taking into account the evolution of the transport regulations
Experience dry storage of spent fuel Belgium
4
Dry storage spent fuel Doel
20/05/2014
• Solution : Disconnect storage authorization from package design approval : proposed new requirements:
1. Valid package design approval at the time of loading
2. Maintain “on-site transferability” during storage (availability of procedure and equipment to transfer, if requested to manage an incident on a cask, the Spent Fuel dual purpose cask to pool’s unit in a safe way evaluated every 5 years)
3. Every 10 years (safety review of NPP) : assessment of possibilities to transport for final disposal (package design approval still possible or transfer to an other cask (hot cell or pool) or transport under special arrangement)
Experience dry storage of spent fuel Belgium
5
Dry storage spent fuel Doel
20/05/2014
• Easy way to comply with new approach : continue to renew the certificate for as long as it is possible
• How to apply this if a prolongation of the package design approval certificate is no longer possible ? :• Integrated Transport and Storage Safety
Case for Dual Purpose Casks for Spent Nuclear Fuel on basis of :• Safety Analysis Report (SAR)• Storage safety file (TSAR)• Gap analysis
• …Experience dry storage of spent
fuel Belgium6
Dry storage spent fuel Doel
20/05/2014
TN24 spent fuel cask
Experience dry storage of spent fuel Belgium
7
Experience dry storage of spent fuel Belgium
20/05/2014
Filling of dry storage
• Loading, drying and conditioning of casks • Transfer on site to storage building SCG• Vertical storage
• No shock absorbers• No secondary lid → Anti-missile shield• Storage pad• Leak tightness control• Thermal control• Visual inspections
8
Experience dry storage of spent fuel Belgium
TN 24 Entity # assemblies
Assembly size
Assembly
length
SH Doel 1-2 37 14x14 2900
D Doel 3 28 17x17 4030
DH Doel 3 28 17x17 4030
XL Doel 4 24 17x17 4795.4
XLH Doel 4 24 17x17 4795.4
20/05/2014
Dry storage spent fuel Doel
9
Experience dry storage of spent fuel Belgium
This image cannot currently be displayed.This image cannot currently be displayed.
20/05/2014
Dry storage spent fuel Doel
10
Experience dry storage of spent fuel Belgium
TN 24 # casks stored
Cooling time (av)
Years
Max. burnhup
GWd/t
Max. enrichment
%
SH 27 5 55 4.55
D 10 8 36 3.4
DH 24 7 55 4.5
XL 8 8 40 3.3
XLH 18 7 55 4.36
20/05/2014
Storage in SCG Doel
11
Storage in SCG Doel
• TOTAL: 87 loaded storage casks• Capacity Storage building SCG
• First part: 56 containers• Second part: 112 containers• TOTAL: 165 positions (3 obligatory empty)
• Storage building is half full• Extension of storage capacity?
12Experience dry storage of spent fuel Belgium
20/05/2014
This image cannot currently be displayed.
20/05/2014
Incidents
Experience dry storage of spent fuel Belgium
• Detection of leaking fuel at cask loading• Water sample
• Defective second seal for one cask• Leak tightness was always
guaranteed• Transport to fuel pool of D4• Reflooding of cask• Changing lid and seals• Loosening of silicons
• Intervention on pressure monitors• Configuration of pressure gauges has
changed• Radiation level locally above expected value
13
This image cannot currently be displayed.
20/05/2014
Conclusion
Experience dry storage of spent fuel Belgium
• The dry storage of spent fuel at Doel is stable and safe• Only minor incidents
• Storage is half full• Renewal of packaging approval certificate • Transport after storage can be a challenge• Closing of Doel 1-2
• Cooling time for spent fuel • Capacity per packaging
14
Thank you for your attention
20/05/2014
Transnubel
Experience dry storage of spent fuel Belgium
15
