International Atomic Energy Agency

1

IAEA Safeguards at the Independent Spent Fuel IAEA Safeguards at the Independent Spent Fuel Storage Installation, Chinshan Nuclear Power PlantStorage Installation, Chinshan Nuclear Power Plant

SGOA3 & SGTS-TND SGOA3 & SGTS-TND 2012/01/242012/01/24

International Atomic Energy Agency2

• Background

• Spent Fuel Transfer & Storage Process

• Safeguards- By- Design

• Safeguards Measures

• Detection of Missing Pins with DCVD

• Summary

TopicsTopics

International Atomic Energy Agency3

• 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.

BackgroundBackground

International Atomic Energy Agency4

Spent Fuel Transfer & Storage ProcessSpent Fuel Transfer & Storage Process

Transportable Storage Canister -will be loaded with 56 spent fuel assemblies

TFROD 2.12 mID 1.72 mHt. 5.13 mWt. 46.18 t

TSCOD 1.70 mHt. 4.84 mWt. 16.65 t

Transfer Cask - to convey the TSC from the spent fuel ponds into the VCC.

56 SFAs

AOSSq. foot 4.5 x 4.5 mOD 4.20 mWall thk. 0.35 mHt. 6.03 mWt. 81.20 t

Add On Shield - to provide additional shielding for radiation protection.

Final installation

TSC/SFAs are loaded into

TFR

Vertical Concrete Cask-used for long storage of the spent fuel assemblies

VCCOD 3.45 mID 1.89 mHt. 5.70 mWt. 112.73 t

TSC/SFAs are loaded into

VCC

International Atomic Energy Agency5

Spent Fuel Transfer & Storage Process (cont’d)Spent Fuel Transfer & Storage Process (cont’d)

Tie DownDeconH2 MonitoringShield Lid WeldedPneumatic TestDrainVacuum DryHe PurgePort Cover WeldedHe Leak TestStructure Lid Welded

Shield LidLift upWashDrain

Fuel Loading

TFR/TSC Preparation

TFR ImmersingPositioning

VCC ReadyAdapter ReadyTFR LiftingTie DownTSC TransferVCC Closed

VCC Moving

ISFSI

Transfer

Day-11

Day-12 Day-13/14

Day-1/2/3

Day-3

Day-4/5/6Day-7 Day-

7/8/9/10

Storage monitoring

International Atomic Energy Agency6

• 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- By- DesignSafeguards- By- Design

International Atomic Energy Agency7

Safeguards MeasuresSafeguards Measures

Tie DownDeconH2 MonitoringShield Lid WeldedPneumatic TestDrainVacuum DryHe PurgePort Cover WeldedHe Leak TestStructure Lid Welded

Shield LidLift upWashDrain

Fuel Loading

TFR/TSC Preparation

TFR ImmersingPositioning

VCC ReadyAdapter ReadyTFR LiftingTie DownTSC TransferVCC Closed

VCC Moving ISFSI

Transfer

Day-11

Day-12Day-13/14

Day-1/2/3

Day-3

Day-4/5/6Day-7 Day-

7/8/9/10

Storage monitoring

UW cam

InspectorSeals on the VCC Dual seals

Surveillance in reactor hole (RH)

Surveillance in transfer hatch

Inspector

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

International Atomic Energy Agency8

Safeguards Measures (cont’d)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.

International Atomic Energy Agency

Detection of Missing Pins with DCVDDetection of Missing Pins with DCVD

9

• 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.

International Atomic Energy Agency

Detection of Missing Pins with DCVD (cont’d)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.

Missing pins

International Atomic Energy Agency11

SummarySummary 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.

International Atomic Energy Agency12

Thank you for your attentionThank you for your attention

Any questions?Any questions?