ML042920186

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10/8/04, Watts Bar, Unit 1, Attachment 2, Meeting Summary of 8/26/04
ML042920186
Person / Time
Site: Watts Bar Tennessee Valley Authority icon.png
Issue date: 10/08/2004
From: Robert Pascarelli
NRC/NRR/DLPM/LPD2
To:
Tennessee Valley Authority
Pascarelli,R J,NRC/NRR/DIPM,415-1245
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ML042920096 List:
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Download: ML042920186 (19)
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Text

II Steam Generator Replacement Project Status/issues L.

August 26, 2004 Attachment 2

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,:I I \- Purpose

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  • Expectations

I S 77miI

  • Increased tube surface area
  • Integral loose parts strainer provided for FW/AFW
  • Reduced moisture content at exit steam
  • Advanced tube support grid to reduce contact length w/tubes
  • Shellside recirculation nozzle and sparger for chemical cleaning
  • Additional access handholes
  • Snaplock Nozzle Dams provided for dose reduction
  • Electro Polished Head Bowls for dose reduction rI

p - - I -- S 0 Uprate capability from 3475MWt to 3720MWt (future)

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  • Nozzles compatible with high chromium content piping
  • Preheater designed to eliminate warmup during startup
  • "Tempering Flow" for Aux FW nozzle warming eliminated 4 i,
  • Shellside blowdown from hot or cold side or combination

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  • Increased steam pressure of- 50 #
  • 12% Tube plugging margin vs 8%-10%
  • 50 year fatigue life F -

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Parameter OSG RSG Steam Pressure (Thermal Design) 980 psia 1030 psia Max Moisture Carry Over .25% .10%

Nominal Tube OD 0.75 in. 0.75 in.

Tube Wall Thickness 0.43 in. 0.43 in.

Number of Tubes 4674 5128 Min. U-Bend Radius 2.25 in. 3.188 in.

Tube Bundle Length 27.39 ft. 37.04 ft.

Max Plug Level 10% 12%

Tube Material 1600 Alloy 690 Upg Secondary Side HT Area 48,000 sq. ft. 68,000 sq. ft.

Primary Side Volume / SG 935 cu. ft. 1193 cu. ft.

Secondary Side Volume / SG 5947 cu. ft. 5618 cu. ft.

Total RCS Volume 11,789 cu. ft. 12,821 cu. ft.

Dry Weight 352 tons 380 tons

.. . 'a A Secondary Side Liquid Mass 100% Power Secondary Side Steam Mass 100% Power 95,000 Ibm 9,000 Ibm 109,549 Ibm 7,618 Ibm

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I

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  • One Piece Replacement like SQN
  • Major Activities Involved:

- Obtain & Assemble Large Crane

- Build Support Facilities

- Defuel Reactor

- Cut holes in Shield Building, L-1 I["'

Steel Containment Vessel (SCV),

and SG Compartment Roofs F1 EL*>1R - Remove Old SGs F a - Install Replacement SGs

- Restore SG Compartments, SCV, and Shield Building

- Refuel Reactor 4.. .. - Pressure Test to Demonstrate Restored Containment Integrity

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  • Shield Building, SCV and SG Compartment Modifications are Similar to SQN and Will Use Same Methodology
  • Safe Load Paths and Load Drop Analysis for Crane Components, Steam Generators, and Other Heavy Loads under Development
  • Using Lessons Learned From SQN

- Movement of Material to SCV Dome

  • N-1 Design Packages - Issued or in final review to issue
  • SGRO Design Packages - Several reaching 10% Status i Coordinating with Security to maintain compliance with DBT Security Order
  • I S

- RSG with 2 F T-Avg Reduction e

<..2Ln \- Input Parameters

  • Primary Reactor Operating Conditions for 0%, 12% SG Tube Plugging
  • Best Estimate Steam Parameters for Turbine/BOP Cycle

- Safety

  • LOCA Mass & Energy/Containment Integrity
  • MSLB Mass &Energy/Containment Integrity
  • SG Tube Rupture
  • Steam Releases for Dose Analysis

- Control Systems

  • Margin to Trip Analysis
  • Low Temp Over Pressure Protection System
  • RCS and Steam Pressure Control Systems

- Components

  • Component Reviews

- Pumps, Valves, Tanks, Heat Exchangers

- Fuel Design

- Reactor Coolant Loop Piping

- Systems

  • Fluid Systems
  • NSSS/BOP Interface Review

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- Plan to demonstrate original and replacement SG equivalence and compliance w/existing NRC acceptance criteria

  • Seismic Spectra B+C used per UFSAR 1;~
  • Use coupled analysis of interior concrete structure & NSSS loop

- 2 0 F Tavg Reduction

- 2% Increase in Pressurizer Level Operating Range

- SG FW Operational Changes

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  • Known License Amendment/Relief Requests

- Use of Bar-Lock Mechanical Couplers instead of Cadwelds for Rebar Splicing during Shield Building Restoration

- Opening of Penetrations in Shield Building Dome during Modes 1-4 for Material Handling

- SGTR Operator Action to Prevent Overfill

- Additional Ice Bed Total Weight (Ice Bed Tech Spec)

- SG Water Level Setpoints

- Revise APC Specifications

- Use of Pressure Test rather than CILRT for PMT of restored Steel Containment Vessel like SQN

II - - 0

  • y hi; *Potential License Amendment Requests

- Compensatory Measures due to Load Drop i-

  • WBN evaluating whether a license amendment and compensatory measures for rigging and transport of steam generators are needed SQN License Amendment Requests Not Required for WBN

- SG Compartment Restoration

  • License amendment for a code change not required, since existing WBN design is more robust compared to SQN
  • Will use design similar to SQN I -

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.i Items Of Note

1. Use of Bar-Lock Mechanical Couplers instead of Cadwelds for Rebar Splicing during Shield Building Restoration

- Propose not performing pre-use qualification testing P

  • Same application as NRC approved for SQN
  • Couplers purchased from same vendor and dedicated I same as SQN I

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  • Material, process and QA program are same 1

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  • Sister splice testing will verify adequacy of installed couplers p

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[< A Opening AN2. of Penetrations in Shield Building Dome K; J during Modes 1-4 for Material Handling

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., -One-time change to Tech Spec 3.6.15 (Shield Building)

'I trequired during Cycle 6 1._t - Allows material movement to SCV dome through Shield Building dome versus through Auxiliary Building and up ladder K. iin annulus

- 1Will reduce time spent in annulus and minimize personnel dose

- Will reduce congestion and delays at annulus ladder

- Will reduce potential for damage of SSCs along path through Auxiliary Building and annulus s- Offsite Dose Impacts

- Mission Dose Impacts L

p 0 - - S -.

ii / 3. NSSS Reactor Coolant Loop Reanalysis Replacement Steam Generator (increase in mass and change in stiffness) constitutes a modification to Reactor Coolant Loop K Xreanalysis. For New/Modification of items, UFSAR requires use of Seismic Spectra Set B+C rather than previous Spectra Set A evaluated to Spectra B.

- Couple Interior Containment Structure (ICS) with the Reactor Coolant Loop (RCL)

.* Original:

4-Loop RCLlsupports model (uncoupled)

.- Set A Amplified Response Spectra (ARS) input at highest loop support location t Reanalysis:

Loop RCUsupports coupled with ICS A - Set B+C ARS input at basemat elevation

I__

I m u m

, lwith UFSAR

, .replacement (Wolf Creek, Callaway, Farley, McGuire, Catawba)

D Seismic Analysis Methodology

  • Original: 2-D input/combination methodology per original FSAR
  • Reanalysis: 3-D input/combination methodology per UFSAR
  • WBN piping and supports analyzed using 3-D method for Sets B and C Seismic Input.
  • UFSAR specifies 3-D for new design and modification analyses
  • Consistent with SRP 3.7.2 k ..- a.

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./ G PIPESTRESS Computer Code used for RCL Reanalysis Original; WESTDYN-7 4 *Reanalysis: PIPESTRESS

  • Approved for analysis of AP600 piping systems.

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  • License Amendment Submittal Schedule j;

- Open Temporary Holes in Shield Building Dome - 11/04

- SGTR Operator Action to Prevent Overfill - 12/04

- Load Drop Compensatory Measures (if required) - 5/05

- Additional Ice Mass - 7/05

- SG Water Level Setpoints - 8/05

- Revise APC Specifications - 8/05

- Use of Pressure Test rather than CILRT - 8/05

d- S mid : h :

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  • Implementing SQN Lessons Learned and Best Practices
  • Addressing Licensing/Design Basis differences with SQN
  • Plan is to provide minimum of 1 year staff review time H0

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