IAEA Safeguards at the Independent Spent Fuel Storage Installation, Chinshan Nuclear Power Plant SGOA3 & SGTS-TND 2012/01/24

Topics Background Spent Fuel Transfer & Storage Process Safeguards- By- Design Safeguards Measures Detection of Missing Pins with DCVD Summary

Background Cinshan nuclear power plants consist of two 636 MWe BWRs which have been in operation over 30 years. The spent fuel ponds (SFPs) are nearing the capacity of their storage capability. An independent spent fuel storage installation (ISFSI) is under construction with space for 1680 spent fuel assemblies (SFAs). The IAEA and TWN authorities are implementing safeguards by-design features and innovative technology which were adopted in the early design stage of ISFSI.

Spent Fuel Transfer & Storage Process 56 SFAs Vertical Concrete Cask-used for long storage of the spent fuel assemblies VCC OD 3.45 m ID 1.89 m Ht. 5.70 m Wt. 112.73 t TSC/SFAs are loaded into VCC TSC OD 1.70 m Ht. 4.84 m Wt. 16.65 t TSC/SFAs are loaded into TFR TFR OD 2.12 m ID 1.72 m Ht. 5.13 m Wt. 46.18 t AOS Sq. foot 4.5 x 4.5 m OD 4.20 m Wall thk. 0.35 m Ht. 6.03 m Wt. 81.20 t Add On Shield - to provide additional shielding for radiation protection. Final installation Transportable Storage Canister -will be loaded with 56 spent fuel assemblies Transfer Cask - to convey the TSC from the spent fuel ponds into the VCC.

Spent Fuel Transfer & Storage Process (cont’d) Day-1/2/3 TFR/TSC Preparation Day-3 Day-7 Day-7/8/9/10 TFR Immersing Positioning Day-4/5/6 Shield Lid Lift up Wash Drain Fuel Loading Tie Down Decon H2 Monitoring Shield Lid Welded Pneumatic Test Drain Vacuum Dry He Purge Port Cover Welded He Leak Test Structure Lid Welded Day-12 Day-13/14 ISFSI VCC Moving Day-11 Storage monitoring VCC Ready Adapter Ready TFR Lifting Tie Down TSC Transfer VCC Closed Transfer

Safeguards- By- Design Two important features were incorporated in early design stage of the ISFSI; 1. Innovative Digital Cerenkov viewing device (DCVD) technology to perform SF verification for PD. 2. Unique dual sealing arrangement to address all credible diversion scenarios. Reduction of field efforts to a minimum level was an important factor in the design process. According to Agency requirements: LWR spent fuel assemblies considered as easily dismantle are due to partial defect (PD) verification when transferred to difficult to access conditions, in order to assure that at least half of the fuel rods are present. Continuity of knowledge (CoK) will be maintained by means of containment and surveillance during the SF transfer process.

Safeguards Measures ISFSI Transfer Day-1/2/3 Day-3 Day-7 Day-7/8/9/10 Storage monitoring UW cam Inspector Seals on the VCC Dual seals Surveillance in reactor hole (RH) Surveillance in transfer hatch SDIS A (main) SDIS B (back up) Inputs From UW& reactor building cameras Remote Monitoring (RM) Spent fuel is verified by DCVD for PD prior to loading Day-1/2/3 TFR/TSC Preparation Day-3 Day-7 Day-7/8/9/10 TFR Immersing Positioning Day-4/5/6 Shield Lid Lift up Wash Drain Fuel Loading Tie Down Decon H2 Monitoring Shield Lid Welded Pneumatic Test Drain Vacuum Dry He Purge Port Cover Welded He Leak Test Structure Lid Welded Day-12 Day-13/14 ISFSI VCC Moving Day-11 VCC Ready Adapter Ready TFR Lifting Tie Down TSC Transfer VCC Closed Transfer

Safeguards Measures (cont’d) The VCC is the containment for the spent fuel - for safeguards purposes - on which the dual seals are applied. The top cover of the VCC in conjunction with AOS side walls are the components to be sealed and immobilized to the concrete pad.

Detection of Missing Pins with DCVD The Cerenkov light emitted from SFA is recorded as a digitized image. PDT is performed in real time by quantitative analysis of the Cerenkov light pattern with custom software (DCView). Cerenkov light intensity emitted from SFA is a function of burn up (BU) and cooling time (CT). Pin substitution by un-irradiated dummies leads to a decrease of light intensity, pin removal to an increase.

Detection of Missing Pins with DCVD (cont’d) Missing pins lead to high intensity spots on Cerenkov light image. Missing pins are detected and marked by an automated analysis in DCView based on local intensity comparison with fuel template. DCView software performs comparison between measured Cerenkov light intensity and expected intensity values calculated from declared BU and CT. Off-line re-evaluation is possible.

Summary Safeguards-by-design features and a process by which they were successfully incorporated in the design phase, have been introduced. Innovative DCVD technology for PD verification of SF, prior to its shipment to difficult to access conditions, has been presented. Unique dual sealing arrangement to maintain CoK on SF which is stored in difficult to access conditions, has been presented.

Thank you for your attention Any questions?