ML021510020

May 30, 2002, Palo Verde Meeting Handouts

ML021510020
Person / Time
Site:	Palo Verde
Issue date:	05/30/2002
From:	Arizona Public Service Co
To:	Office of Nuclear Reactor Regulation
References
Download: ML021510020 (14)

Text

Nuclear Fuel Update Palo Verde Nuclear Generating Station May 30,2002 Meeting with US NRC Review of 2001

• March 2001 Meeting with NRR

+ Approval of new MDNBR Limit

• Progress with Clad Performance

+ Alloy A LFA Approved For 4th Burn

• CENTS Code Added to COLR

• Begin Transition to Westinghouse Rod

• Zirlo Tech Spec Submitted 7.

I

Agenda Today

+ Review of Unit 2 Cycle 11

• CENTS Implementation & Licensing

1. Integrated Clad Performance Strategy

+ Update on CEA Investigation

+ Dry Cask Storage Update Unit 2 Cycle 11 Activities Incorporated in the Reload Safety Analyses 4

2

U2C1 1 Reload Analyses

+ Implementation of New MDNBR Limit

• Manufacturing Transition to Columbia

• Implementation of Zirlo Clad & New LOCA Methodology

• Implementation of New CENTS AORs CENTS System Code Implementation & Licensing 3

CENTS Implementation Plan

+ Generic Letter 83-11 Supplement 1

• All UFSAR Chapter 15 Analyses

+ Two Events Remain In Progress

- Steam Generator Tube Rupture

- CEA Ejection Dose Consequences Steam Generator Tube Rupture

• Consequences Increase > Minimal

• Principal Contributors

- Timing of Aux FW & ADV opening

- New Limiting SG Level

• Retain Current CESEC AOR Until CENTS Analysis Reviewed & Approved

• Consistent With RSG/PUR Submittal 8

CEA Ejection Dose Consequences

• Evaluating CENTS Applicability

+ Will Submit if Required

+ Retain Current CESEC AOR Until CENTS Implemented

• Will Not Impact RSG/PUR 9I Submittal Palo Verde Integrated Clad Performance Strategy Review of Recent Capabilities U2 Uprate Corrosion Strategy 10

Integrated Fuel Clad Strategy

• Advanced Clad Alloys

1. Primary System Chemistry

• Higher Order Modeling

• Low Duty Core Designs Advanced Clad Alloys

• Full Batch Zirlo starting U2C1 1 (Spring 2002)

• Alloy A LTA in U3C1 0 (Spring 2003)

• Continuing Discussions with Westinghouse 12 6

Primary Chemistry

• Additional RCS Cleaning at EOC Shutdown

1. Early Lithium Injection During Startups

• Elevated-Coordinated Lithium Strategy

- Currently 7.1 pH

- Inspection U1 R1 0 (Fall 2002)

- Gradual Increase to > 7.2 pH 13 Higher Order Modeling

• Uncertainty in Behaviors

• Multiple Models

• Steaming Rate Function in Design Tools

- U3C9 Benchmark

+ APS CRUD/Oxide Model

- Pin x Pin Colorset and Coarse Mesh Octant

+ Vendor Fuel Duty Model

- Oxide and FDI for all Clads 14 "7

Low Duty Core Designs

• Increase Feed Batch Size

- 104 vs 96 Assemblies

• Minimal Feed-Face-Feed

+ U2 Uprate Corrosion Strategy

- 3% Power and 2 2F Coolant Temperature

- Zirlo Clad

- Re-design Lattice Pattern 15 8

Review of CEA Replacement

+ CEA Finger Failures Observed - all Units

- Significant Cracks in High Fluence CEAs

- Boron Loss in U1 Lead Group

- Some Medium Fluence CEA Cracking

- U2R8 CEA Found Cracked (Jan. 2002)

1. All Full Length CEAs Replaced

- Two Different Tip Designs

- Replaced by Design with Smallest Pellet 9

Apparent Cause of Failures

• IASCC of Cladding

- Irradiation Sensitized Inconel

- Swelling-induced Strain

1. Less than Adequate Design Testing

- Feltmetal Properties Unverified at High Duty

- Pellet-Feltmetal Interaction

• Lifetime Predictive Software

- Models Not Fully Benchmarked 19 Remaining Actions

• Determine Conservative Estimate of Life

- 2 Cycle Fingers OK

- Possible YGN Inspections

- Possible Hot Cell Exams

- 2x1 0 21 n/cm 2 Threshold?

+ CEA re-Design for the Future 20 10

11 Project Schedule

• Concrete Cask fab completed 3/31/02

• First Canister delivery 6/28/02

+ ISFSI Construction complete 8/19/02

• Security features installed 9/15/02

+ Dry run practice begins 8/1/02

• NRC dry run observations mid Novermiber

• First system on the pad by Christmas

• *t2Ž t.*'44g U

Co pleted VCCs Palo Verde Dry Cask Storage Principal I Components Adapter Plate (Cut-away View) with Hydraulic 4

Actuated Doors Vertical Concrete Dimensions: Storage Cask Dimensions:

Transfer cask Ht. 16 ft. 11 in.

Dia. 7ft. 1 in.

Loaded canister Ht. 15ft. 11 in.

Dia. 5 ft. 7 in.

vCC Ht. 18ft. 10 in.

Dia. 11ft. 4 in.

Weight:

Transfer cask 60 tons Loaded canister 35 tons vCC 119 tons Loaded system 154 tons