© 2017 Electric Power Research Institute, Inc. All rights reserved.

Keith Waldrop

Principal Technical Leader

Tribal Caucus Midyear Meeting

Charlotte, NC

January 25, 2017

High Burnup

Data Project

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Background

For low burnup fuel, sufficient data exist to

support licensing

Based on demo with low burnup fuel

– No evidence of degradation after 14 years

– No visual evidence of additional assembly/cladding degradation or bowing

– Little to no detachment of crud

– Still significant creep life left in cladding

Provided basis for license renewal for low burnup fuel

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Background

High burnup fuel technical basis from laboratory testing

– Lab tests show hydrides in clad can reorient though heatup and

cooldown during dry storage loading operations

Radial hydrides (after

heatup/cooldown)

Circumferential hydrides (before

heatup)

– Hydride reorientation causes shift in ductile to

brittle transition temperature (DBTT)

May become brittle at temperatures fuel

will reach during storage

Loss of ductility is primarily a concern for

transport conditions, not storage

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Background

Lab data provided basis for loading HBU fuel in dry storage

– Technical basis provided in US NRC ISG-11 Rev 3 (Nov-2003)

Creep will not cause gross rupture

“…until the effects of reorientation are better understood, the

hoop stress on the cladding should be controlled to preclude the

formation of radially oriented hydrides.”

Limit hydride reorientation

– Limit cladding temperature to 400°C to limit hoop stress and

soluble hydrogen

– Limitations of ISG-11 Rev 3

Limited to initial license period (20 yrs)

Not applicable to transport

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Background – Why We Need Data From HBU Data

Project

Limited data on HBU fuel in dry storage

– Storage licenses for HBU fuel need to be extended

– Transport licenses for HBU fuel are very limited and restricted

Data available are from lab testing

Need to collect data on HBU fuel – real fuel, in a real cask,

under real conditions

– Repeat earlier low burnup demo using high burnup fuel

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High Burnup Data Project – Big Picture

Load cask with High Burnup fuel

– Select fuel to provide best scientific data

– Obtain “t=0” data from sister rods (non-destructive and

destructive examinations)

– Instrument cask to acquire data (temperature and gas

composition)

– Use standard industry loading process

– Collect data

After ~10 years in storage:

– Ship to examination facility

– Open cask and inspect fuel

– Examine rods to compare to “t=0”

Re-close and continue storage and measurements

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Fuel Selection

1 2 (TC Lance) 3 4

6T0 3K7 3T6 6F2

Zirlo, 54.2 GWd M5, 53.4 GWd Zirlo, 54.3 GWd Zirlo, 51.9 GWd

4.25%, 3cy, 11yr 4.55%, 3cy, 8yr 4.25%, 3cy, 11yr 4.25%, 3cy, 13yr

1013/818W 1167/837W 1015/820W 909/756W DRAIN PORT

5 6 (TC Lance) 7 8 9 10

3F6 30A 22B 20B 5K6 5D5

Zirlo, 52.1 GWd M5, 52.0 GWd M5, 51.2 GWd M5, 50.5 GWd M5, 53.3 GWd Zirlo, 55.5 GWd

4.25%, 3cy, 13yr 4.55%, 3cy, 6yr 4.55%, 3cy, 5 yr 4.55%, 3cy, 5 yr 4.55%, 3cy, 8yr 4.2%, 3cy, 17yr

914/761W 1276/832W 1503/841W 1477/827W 1163/834W 906/796W

11 Vent P o rt 12 13 14 (TC Lance) 15 16

5D9 28B F40 57A 30B 3K4

Zirlo, 54.6 GWd M5, 51.0 GWd Zirc-4, 50.6 GWd M5, 52.2 GWd M5, 50.6 GWd M5, 51.8 GWd

4.2%, 3cy, 17yr 4.55%, 3cy, 5 yr 3.59%, 3cy, 30yr 4.55%, 3cy, 6yr 4.55%, 3cy, 5 yr 4.55%, 3cy, 8 yr

885/778W 1496/837W 699/?W 1281/834W 1482/830W 1120/803W

17 18 19 (TC Lance) 20 21 22

5K7 50B 3U9 0A4* 15B 6K4

M5, 53.3 GWd M5, 50.9 GWd Zirlo, 53.1 GWd Low-Sn Zy-4, 50 GWd M5, 51.0 GWd M5, 51.9 GWd

4.55%, 3cy, 8yr 4.55%, 3cy, 5 yr 4.45%, 3cy, 10yr 4.0%, 2cy, 22yr 4.55%, 3cy, 5 yr 4.55%, 3cy, 8 yr

1165/835W 1492/835W 1037/805W 725/664W 1496/837W 1121/804W

23 24 (TC Lance) 25 26 27 28 (TC Lance)

3T2 3U4 56B 54B 6V0 3U6

Zirlo, 55.1 GWd Zirlo, 52.9 GWd M5, 51.0 GWd M5, 51.3 GWd M5, 53.5 GWd Zirlo, 53.0 GWd

4.25%, 3cy, 11yr 4.45%, 3cy, 10yr 4.55%, 3cy, 5 yr 4.55%, 3cy, 5 yr 4.4%, 3cy, 8yrs 4.45%, 3cy, 10yr

1036/837W 1031/801W 1495/837W 1511/846W 1178/843W 1035/803W

29 30 31 (TC Lance) 32

4V4 5K1 5T9 4F1 High Priority Assys

M5, 51.2 GWd M5, 53.0 GWd Zirlo, 54.9 GWd Zirlo, 52.3 GWd

4.40%, 3cy, 8yr 4.55%, 3cy, 8yr 4.25%, 3cy, 11yr 4.25%, 3cy, 13yr

1073/787W 1155/828W 1031/832W 918/764W

Burnup

Clad Type Qty Range

Zr-4 1 50.6

low tin Zr-4 1 50

Zirlo 12

51.9 -

55.5

M5 18

50.5 -

53.5

KEY

Location (Thermocouple)

Assy ID (high priority)

Clad , BU

Enr, #cycles, Yrs cooled

Decay Heat (loading), (transport)

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Fuel Selection

Peak cladding temperatures too low for hydride reorientation

– Current best estimate using detailed decay heat calculation predicts

peak cladding temperature of 271°C

– Good news story:

This is typical of HBU casks, not bounding

Hydride reorientation not a concern for most casks considering

actual temperatures

– PNNL plans to do additional analysis for other systems loaded with

high heat load

– Sister rod testing to address gap for higher clad temperatures than in

this cask

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Thermocouples

Technical goals:

– Determine true temperature distribution

– Provide benchmark data for thermal models

Design considerations:

– Thermocouple penetrations and confinement

– Thermocouple lance emplacement (radial and axial)

– Temperature measurement reliability/longevity

– Thermocouple calibration

Fabrication complete

Thermocouple testing

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Gas Sampling

Collect gas sample from cask cavity

– Attach sample bottle to vent port

– Fission gas, oxygen, hydrogen analyzed in site lab

– Moisture measured with Moisture Vapor Isotope

Analyzer

Take gas samples while cask is still in decon

building

– No unmonitored release

– Dominion can pass leak test after gas sampling

Dominion proposed approach for sampling

during storage period using temporary enclosure

– Licensing risk with this approach

– Not included in initial license amendment

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Sister Rods

Extracted 9 AREVA M5 rods from 2 assemblies

Extracted 14 Westinghouse rods from 4 assemblies

– 12 Zirlo™, 2 low-tin Zr-4

2 additional Zr-4 rods

Rods shipped to ORNL

DOE developed draft sister rod test plan

Non-destructive testing underway

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Cask Modification

Lid machining

Initial cask fit-up test

Thermocouples

Data acquisition system

Lid machining Data acquisition systemThermocouple testingFit-up test

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High Burnup Data Project Schedule

2017:

Complete lid and cask modification and testing

Ship cask, lid and instrumentation to North Anna

Obtain storage license from NRC (pending NRC

review)

Perform dry runs

Load Demonstration Cask and begin

temperature and gas data collection

Submit amendment for taking gas samples at the

ISFSI

Complete non-destructive examinations of sister

rods

Complete test plan for destructive sister rod testing

Begin destructive examinations of sister rods

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High Burnup Data Project Schedule (con’t)

2018 - ~2027:

Obtain storage license amendment from NRC for gas

sampling at pad

Continue taking periodic temperature measurements

Continue taking periodic gas samples at pad

Submit and obtain transportation Certificate of

Compliance (CoC) from NRC

(tentative, pending NRC review)

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High Burnup Data Project Schedule (con’t)

~2027

Return Demonstration Cask to the North Anna Power Station

Prepare cask for transport to an off-site Fuel Examination Facility

Ship cask to a Fuel Examination Facility (to be provided by DOE)

Open cask and visually examine the fuel

– Extract high burnup rods for subsequent examination

– Conduct non-destructive and destructive examinations of the rods at

the national lab(s)

Same exams as “t=0” exams

Compare end-of-storage and “t=0” fuel properties

Re-close cask and continue storage; re-open again later

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Together…Shaping the Future of Electricity