ML020730229

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Meeting,Tennessee Valley Authority Browns Ferry Nuclear Plant Alternative Source Term Implementation
ML020730229
Person / Time
Site: Browns Ferry  Tennessee Valley Authority icon.png
Issue date: 02/28/2002
From:
Office of Nuclear Reactor Regulation
To:
Office of Nuclear Reactor Regulation
References
TAC MB3631
Download: ML020730229 (14)


Text

Tennessee Valley Authority Browns Ferry Nuclear Plant Alternative Source Term Implementation TVA/NRC Meeting Nuclear Reactor Regulation - Rockville MD January 16, 2002

Agenda

" Introduction/Meeting Objectives

" Schedule

" Background

" Analysis Approach

" Analysis Attributes

  • Submittal Contents
  • Summary and Open Discussion Steve Austin 1

Introduction/Meeting Objectives

"* Introduction

" Previous Meeting Extended Power Uprate

" Meeting Objectives

- Discuss the BFN Approach

- Discuss Submittal Content and Depth of Information

- Obtain NRC Concurrence of TVA's Proposed Methodology

- Gain NRC Insights From Other Alternative Source Term Submittals Steve Austin 2

Schedule Ot,1n EL=

2003 El May 02 TVA Submittal To NRC For AST TVA Submittal To NRC For EPU Sprin W2C12 Outage US2CpI Outage EPU Full Tm-'ementation Spring U3011 Outage EPU Full Implementation Steve Austin 3

E--

2004 El 2005 200R El 2:07 L

NRC SER For AST NRC SER For EPU Unit-2 1 Outage Unit-3 0

Spring U3C10 Outage win 2003 2004 2

=

Background===

LLL

  • BFN Design Features BWR-4 Mark I Containment

- Inerted Primary Containment

- Secondary Containment Common to Units 1, 2, and 3

- Three Trains of Standby Gas Treatment

- 600 Foot Stack

- Units 1,2, and 3 Control Rooms Have a Common Control Room Emergency Ventilation (CREV) System

- Implemented Main Steam Ruggedness

  • Completed Implementation March 2001 Henry Jones 4

Background (Cont.)

~ Current Radiological Analysis Approach ORIGEN - Source Terms Traditional Regulatory Methods Atmospheric Dispersion Coefficients

"* Used in MSIV Increased Leakage Submittal and Associated NRC SER

"* UFSAR Amendment 19

"* Use Existing Values For AST ECCS Leakage Henry Jones 5

Analysis Approach

  • Follow Reg Guide 1.183, "Alternative Radiological Source Terms for Evaluating Design Basis Accidents As Nuclear Power Reactors"
  • Full Implementation
  • Reran ORIGEN Source Term at EPU Conditions
  • Suppression Pool Water pH Control
  • Filtration Efficiencies
  • No Plant Modifications Anticipated Henry Jones 6

Analysis Attributes

  • NUREG - 0737 - Mission Doses
  • Expressed in Terms of Times and Rates of Appearance of Radioactive Fission Products Released Into Containment
  • Types and Quantities of the Radioactive Species Released
  • Chemical Forms of Iodine Released Henry Jones 7

Drywell Sprays LLI

" Safety Related Redundant Mode of RHR

" Credit for Drywell Sprays (Loss of Coolant Accident)

Boiling Water Reactor Sprays Already Credited for AST

"° Perry

"* Grand Gulf Manual Actuation Drywell Congestion

  • Reduced Spray Being Credited for BFN
  • Reduced Fall Height Being Credited for BFN

- Standard Review Plan 6.5.2 Used for Spray Removal Rate Henry Jones 8

Main Steam Line Break (MSLB) X/Q Outside Containment

  • Current Analysis Approach

- Turbine Building Remains Intact

"* No Credit for Deposition

"* ARCON96 Steady-State Plume X/Q

"* Release Over 2 Hour Time Period

"* Release Through Unit 1 Turbine Building Exhaust (Highest X/Q)

"* Includes Consideration for Dual CREV Intake Henry Jones 9

Main Steam Line Break X/Q (Cont.)

UT Outside Containment

  • RG 1.183 MSLB X/Q Scenario Puff Release Directly to Environment
  • Puff X/Q Used

- Immediate Release Assumed

- No Credit for Deposition

° Rising Puff Credited e NRC Puff Model in Draft Regulatory Guide 1111, "Atmospheric Relative Concentrations for Control Radiological Habitability Assessments at Nuclear Power Plants" Will be Considered Henry Jones 10

Use of AEB-98-03 U&

Use of AEB-98-03 Approach With DW Spray Credit and Multiple Steam Line/Condenser Volumes in Series TVA Plans to Use AEB-98-03 but With DW Sprays and Multiple Steam Line/Condenser Control Volumes in Series DW Sprays Remove Large, Dense Particles Multiple Steam Line/Condenser Volumes in Series Decreases the Sedimentation Velocity Distribution in Downstream Control Volumes Henry Jones 11

Submittal Contents

!L

  • Previous Submittals Duane Arnold

- Columbia

  • Review and Incorporate Applicable AST RAIs
  • Describe Changes
  • Identify the Computer Codes Utilized
  • Identify Inputs and Assumptions
  • Describe the AST Results
  • Identify Affected UFSAR Sections Henry Jones 12

Summary and Open Discussion

"* Evaluations and Acceptance Criteria Will be Consistent With Those Required by 10 CFR 50.67 and Reg Guide 1.183

"* Evaluate Design Bases Accidents

- Acceptable Radiological Analysis Methods and Assumptions

"* Update the Design/Licensing Bases for BFN

- Technical Specifications FSAR

- Calculations

" Open Discussion Steve Austin 13