~~~A B LGopcmany · * Design Basis for OTAT and TM/LP Reactor Trip Functions - Ensures that the DNB...

I , ?

i 1-L -

D, A__ML _

~~~A_ B LGopcmany

Westinghouse Non-Proprietary Class 3

If

Discussion onIncreased Steam Generator Tube Plugging

and Reload Methodology at St. Lucie Unit 2(Transition to WCAP-9272)

BNF SlieI(BNFL Slide 2 0 Westinghouse

Agenda1. Project Background2. Licensing Considerations

2.1. WCAP-92722.2. SER Compliance2.3. RSAC Changes

3. Development Phase Overview3.1. Process3.2. St. Lucie Unit 2 Licensing Basis3.3. Comparison of Current and Transition Methods

3.3.1. Identification of Key Assumptions3.4. Overview of Engineering Review

4. Reload Setpoints Overview4.1. Methods4.2. Uncertainties4.3. Basics

4.3.1. Trips4.3.2. TM/LP & A1 versus OTAT & f(A I)

5. Core Design - Power Shape Generation, RAOC6. T/H - Code, Core Limits, Correlation7. Setpoints Details

7.1. Implementation7.2. Uncertainties

8. RETRAN8.1. Code8.2. Modeling for St Lucie Unit 2

9. Steamline Break9 1. Methods Assumptions and Modeling (General)9.2. SLB Post-trip LOAC

10. Asymmetric SG transient11. Feedline Break12. Documentation Expectations

* Additional topics as time permits* Topics 4 & 7 have been combined and will be

presented on Day 2 per NRCs request

*BNFL Slide 3

CBNFL Slide 3 OWesinghouse

Section 1Project Background

(BNFL Slide 4 SlWestinghouse

Background. Background

- St. Lucie Unit 2:* CE NSSS with analog protection system* 16xl6CEfueldesign* Nuclear Design by FPL with ALPHA-PHOENIX- ANC

Currently uses PAC reload process - CESEC / TORC / FATES /1985EM/S1M

- Cycle 15 will support:* Increase from 15% to 30% SGTP* Reduced TDF (min. TS flow) of 335,000 gpm

Transition ZIRLO claddingTransition to WCAP-9272 reload Methodology

BNFL Slide 5 Westinghouse

Program Roadmap

|30% SGTP / Reduced RCS Flow

ZIRLOI Cladding |

WCAP-9272 Methodology

Re-analysis/re-evaluation of FSAR Chapter 15 Events

LOCA Non-LOCA

|Technical Specification Chne

-- ~Sbitta

Structural, etc.

*BNFL Slide 6 Wo�tinghouse

(BNFL Slide 6 O)Wetinghouse

Section 2Licensing Considerations

I*BNFL Slide 7 6J Westinghouse'OD"BNFL Slide 7 (OWesinghouse

Transition to WCAP-9272-P-A Methodology

* Successfully used in reload analysis of over 540 reactor cores (in use since

1985)

* Westinghouse Reload Safety Evaluation Methodology (WCAP-9272-P-A)

- Defines a bounding approach to the reload evaluation process

- Defines key safety parameters and their limiting direction

- Results in a Reload Safety Analysis Checklist (RSAC) approach for reload

analysis

- WCAP-9272-P-A is applicable to both non-Westinghouse and

Westinghouse reactors

8 BNFL Slide 8 OWesinghouse

Transition to WCAP-9272-P-A Methodology

* St. Lucie Unit 2 transition to WCAP-9272-P-A requires all UFSAR Chapter 15

events to be re-analyzed or evaluated (All limiting events would also need to

be re-analyzed to support 30% SGTP with associated RCS flow reduction and

implementation of ZIRLO)

* The Westinghouse and CE fuel and plant designs are similar and any minor

dissimilarities (i.e., typically input parameters but occasionally a model

change) can be accounted for, and do not invalidate the reload methodology

applicability or philosophy

* Code, selection, use and applicability will be described, explained and justified

OBNFL Slide 9 Wetinghouse

SER Compliance

All code packages that are planned to be used for FSAR cases have been

previously licensed or will be re-licensed as necessary with the NRC

Selection of code packages will be shown to be applicable to WCAP-9272-P-A

Principle areas of licensing focus:

- changes to existing codes and models or new codes and models, and

- changes to existing methodology or new methodology

* "New" means new with respect to the "intended application" (i.e., the

code/model or method was previously licensed, but has been

tailored/customized for the current application)

*BNFL Slide 10 Westinghouse

SER Compliance

Certain items to be submitted to the NRC for review and approval (see next

slide). Since these items would have been previously licensed, the specific

licensing application for St. Lucie Unit 2 should be straightforward

* By identifying changes and areas that may need NRC review, the NRC staffwill

be able to more accurately gauge their resource needs to support the review

* A presentation of changes to existing codes and models or new codes and

models and changes to existing methodology or new methodology will be

provided in the technical presentations

OBNFL Slide 11 Wetinghouse

SER ComplianceActivity

Meeting with NRC to Kick-off the Program

AddendumtoVIPRETopical *

(WCAP-14565-P-A)Acceptance Meeting for Addendum to VIPRE

Topical (WCAP-14565-P-A)Pre-submittal Meeting with NRC on Licensing

Amendment for St Lucie Unit 2Proposed Licensing Amendment for St Lucie

Unit 2 submittal (includes re-write ofChapter 1 5)

Acceptance Meeting for St. Lucie Unit 2submittal

Anticipated NRCSubmittal Date

4/17

5/03

6/03

8/20-21/03

1/04

2/04

Anticipated NRCApproval Date

4/27

5/04

6/03

8/20-21/03

10/1/04

2/04

Status

Completed

Submitted 6/03

Needs to bescheduledScheduled

On-schedule

Needs to bescheduled

* BNFL Slide 12 O Westinghouse

BNFL Slide 1 2 (OWestinghouse

Comparison of MethodsFunctional Discipline Current Code Used Proposed Code Used Com nCore Design ALPHA/PHOENIX- Same No change

P/ANC

Thermal-hydraulic TORC VIPRE Addendum submittal for incorporatingDesign ABB-NV & ABB-TV into VIPRE

(Submitted 06/2003)

Correlation CE-1 /ABB-NV ABB-NV Upgrade correlation with ABB-NVwhich is NRC-accepted for referencingin applications for the St. Lucie Unit 2fuel design

Fuel Rod Design FATES-3B Same No change

Transient Analysis (non- CESEC/STRIKIN-II/ RETRAN/FACTRAN/ Change is within the flexibility of theLOCA) TORC/COAST VIPRE/TWINKLE codes to model both Westinghouse and

CE NSSS

Large Break LOCA 85EM 99EM Upgrade to 99EM which isNRC-accepted for referencing inapplications for CE NSSS

Small Break LOCA Si M S2M Upgrade to S2M which is NRC-acceptedfor referencing in applications for CENSSS

*BN Slide 1 3 S 1Wetinghouse

WCAP-9272 Reload Safety Analysis Checklist (RSAC)

As noted previously, the reload analysis is based on a reference analysis as

documented in a licensee's FSAR

- These analyses cite the key input assumptions and key input parameters

that have the most significant impact on a particular event and specify thecorresponding codes and methods used

- These key input parameters form the basis of Westinghouse's analysis for

the particular plant (i.e., these key input parameters and other inputparameters form the basis of a Safety Analysis Checklist (SAC), or"Baseline Neutronics")

- The SAC (or Baseline Neutronics) becomes the Reload Safety Analysis

Checklist (RSAC) for subsequent reload analyses/evaluations

(BNFL Slide 14 (SWestinghouse

Section 3Development Phase Overview

(BNFL Slide 1 5 *Westinghouse

Process

* General Approach

- Apply standard Westinghouse WCAP-9272 approach, recognizing:

Where changes are required to provide a technically appropriate

modeling of the unique features of the St Lucie Unit 2 design,

operations and Tech Specs

* Where licensing or other considerations warrant a different approach

* Slide 16 Westinghouse

Process

* General Approach

- Do not assume that the current licensing basis assumptions apply to

WCAP-9272 approach or that WCAP-9272 conventional wisdom applies

to St. Lucie 2

* Study each event using first principles to develop strategies and key

assumptions for each event

- Do the homework first

BNR Slide 1 7 Westinghouse

St. Lucie Unit 2 - Licensing Basis

Objectives

- Review and understanding of the licensing basis

0 Expert meeting June 2002

- Review and understanding of the unique features of the St. Lucie Unit 2

design, Tech Specs and operations

- Identification of methods to be used, and the basis for these choices

- Evaluation of the differences between the current basis and the basis

arising from the change in methodology

- Identification of key assumptions for the project technical activities

(BNFL Slide 18 (Wetinghouse

St. Lucie Unit 2 - Licensing Basis

Objectives

- Development of technical and licensing strategies for scoping activities,

definition of event requirements (cases), and outlines for methodsstructured around the standard methods for the technologies being used

- Outline the production phase of the project in which the analyses and

evaluations supporting the January 2004 submittal would be performed

• Extensive study was made of the current St. Lucie Unit 2 licensing basis

- Experts meeting-June 2002

- Review of analysis basis material

(BNFL Slide 19 Westinghouse

Comparisons of Current and Transition Methods

* Comparisons of Current and Transition Methods were undertaken

- ntra-disciplinary meetings to share information, requirements and map

preliminary analysis strategies

- Inter-disciplinary meetings to address interface requirements and

consistency of assumptions and strategies

* Technical Strategies were mapped for each event and reviewed for technical

and licensing appropriateness

- Engineering Review- February 2003

@BNFL Slide 20 OWestinghouse


Continuation of Current Methods

. LOCA

* Fuel Performance

* Mechanical Design

* Steam Generator Tube Rupture

* Containment analysis

OBNFL Slide 21 Westinghouse


Margin Considerations

* A preliminary assessment of margin was performed for key events where 1)

historical margin challenges existed, or 2) changes in methods or assumptions

made margin evaluation indeterminate to provide confidence in the viability of

the transition

* Slide 22 O Westinghouse


Identification of Key Assumptions

Based on the technical strategies and the methods requirements, key

assumptions were identified and confirmed between FPL and Westinghouse

- Includes changes in some assumptions based on margin considerations

(elimination of full power positive MTC, etc.)

- The strategies for analysis were identified and refined through

consultation with FPL, especially in areas of noteworthy differences

• Setpoints/ Uncertainties

* Ful power MTC

* Significant changes in analysis methodology

O BNFL Slide 23 Westinghouse

Overview of Engineering Review

* Focus on

- Aspects for which changes from the current licensing basis

- Proposed changes from standard methods to address the unique features

of the St. Lucie Unit 2 design, Tech Specs and operations

* The presentations which follow are structured around the Engineering Review

material, updated to reflect completed actions and results where available

BNFL Slide 24 9We�in�ouseBNFL Slide 24 . OWestinghouse

1 ---- 7

Section 4 & 7Reload Setpoints Overview & Setpoint Details

BNF Slde2 e We7ighus(DBNFL Slide 25 (sWestinghouse

Introduction

Westinghouse and St. Lucie Thermal Margin Protection Functions a,c


B)1NFL Slide 26 O)Westinghouse

Design Basis for Thermal Margin Trips

* Design Basis for OTAT and TM/LP Reactor Trip Functions- Ensures that the DNB design basis is satisfied for a wide range of RCS

temperatures, pressures, powers and axial power shapes

- Ensures that vessel exit boiling is precluded to ensure that AT isproportional to power

BNFL Slide 27 �Westinghouse(BNFL Slide 27 GWetinghouse

Inputs for Thermal Margin Trips

* OTAT and TM/LP Trip Functions Based on the following Inputs

- Power (AT as indicated by hot minus cold leg temperature in each loop)

- Temperature indication (OTAT => Tavg, TM/LP => Tinlet)

- Pressurizer pressure (range limited by low and high pressure trips)

- Axial Shape as defined by excore detectors (OTAT => top minus bottom

TM/LP => Bottom minus top divided by total power)

* Slide 28 O Westinghouse

Thermal Margin Trip Equations

* Westinghouse Overtemperature AT Reactor Trip function:

Power = K - K2 (Tavg - Tavg') + K3 (P - P') - f(AI)

Sample: Power= 1.35 -0.018 (Tavg - 588') + 0.0085(P-2250) -f(Al)

* St. Lucie TM/LP Reactor Trip function:

Pvar = 1 4 00 x QDNB + 17.85 x Tin - 9410

where QDNB= QR1 function x A 1 function

Rearranging: Power = 1.33 - 0.01275 (Tinlet - 549) + 0.000714 (P- 2250)

AlSlide 29

9 Westinghouse*BNFL Slide 29 (OWestinghouse


* Westinghouse Overtemperature AT f(Al) Function- Reduces the setpoints for skewed axial power shapes based on top minus

bottom excore signal (Al)

f(AI)

0.0AI


(BNFL Slide 30 Westinghouse


* St. Lucie Thermal Margin / Low Pressure A 1 Function- Reduces the setpoints for skewed axial power shapes based on bottom

minus top excore signal divided by total (ASI)

Al

1.0ASI

BNFL Slide 31 WestinghouseGBNFL Slide 31 Wetinghouse

Core Thermal Limits

* Core Thermal DNB Limits- Westinghouse assumes a reference axial power shape (1.55 Chopped

Cosine) to generate the OTAT setpoint

TinletExit Boiling Limits

DNB Limits

High Pressure

Nominal Pressure

Low Pressure

0.0 Power


OBNFL Slide 32 O)Wetinghouse

OTAT Reactor Trip & Core Thermal Limits

* Illustration of OTAT reactortrip with f(Al) = [No penalty]

Tavg Steam Generator SafetyValve Line

,, -

N~ N

NAOvrepraueA

Overpower AT Reactor Trip

I~ High Pressure

I Nominal Pressure

+^ Low Pressure

N

Power0.0

BNFL Slide 33 G WestinghouseOBNFL Slide 33 (OWestinghouse

Setpoints: TM/LP Reactor Trip & Core Thermal LimitsIllustration of TM/LP reactor trip with Al = 1.0 [No penalty]

Tinlet

- -

N%

"T s

Thermal Margin / Low Pressure *.

Steam Generator SafetyValve Line

Variable High Power (AT) Reactor Trip

High Pressure

\ Nominal Pressure

\, Low Pressure

*N

N I

0.0 Power


BNFL Slide 34 (Westinghouse

OTAT Core Thermal Limits for Skewed Shapes

* Locus of Conditions where DNBR is at the limit- Used to define the OTAT f(AI) reset function

0.0 Ai

BNR Slide 35 Westinghouse

TM/LP Core Thermal Limits for Skewed Shapes

Locus of Conditions where DNBR is at the limit

- Used to define the TM/LP Al function

Power

0.0

Slide 36

ASI

*BNFL (OWestinghouse

Check of the TM/LP Reactor Trip Function

Core thermal limits, which include both DNB and exit boiling limits, aregenerated for a wide range of power levels and pressures

The TM/LP reactor trip function, with a bounding ESCU Penalty Factorincorporated into the QR, function and a gamma bias supported by the CEAwithdrawal at power event (-1 75 psi), is determined

The TM/LP trip noted above bounds the core limits from the low pressure tripsetpoint to the high pressure trip setpoint, for temperatures/powers from the steam generator safety valves to a power of 120%

, BNFL Slide 37 Westingouse

Setpoints: TM/LP Trip Function ESCU Penalty Factor

The uncertainties accounted for in the current ESCU Penalty Factor

analysis remain unaffected by the switch to the WCAP-9272 philosophy.

ESCU Uncertainties included in ESCU Penalty Factor: a, c

BNFL Slide 38 G Westinghouse(BNFL Slide 38 Westinghouse

Setpoints: Other Reactor Trip Functions

The following compares other reactor trip functions.

St. Lucie Unit 2 Voatle (Westinahouse olant)Variable High Power - High (107% of RTP)

Variable High Power - Minimum (15% of RTP)Pressurizer Pressure - High (2370 psia)Pressurizer Pressure - Low (TM/LP 1900 psia)Reactor Coolant Flow - Low (95.4%)Steam Generator Pressure - Low (626 psia)Steam Generator Level - Low (20.5% NRS)

High Neutron Flux- High (109% of RTP)

High Neutron Flux - Low (25% of RTP)Pressurizer Pressure - High (2400 psia)Pressurizer Pressure - Low (1975 psia)

Reactor Coolant Flow - Low (90%)Steam Generator Pressure - Low Si (600 psia)Steam Generator Level - Low (35% NRS)

* Slide 39 ()Westinghouse

I

Section 5Core Design - Power Shape Generation, RAOC

BNFL Slide 40 c�We�tinghouse(BNFL Slide 40 (Westinghouse

RAOC Condition I

* Standard 1 D axial model generation

* RAOC EVALUATION.7

.-

a, c

L*BNFL S eWestinghouseSlide 41

RAOC Condition I

FIGURE 4

ST LUCIE UNIT 2 CYCLE 13AO and AFD BAND COMPARISONNO ASI UNCERTAINTY APPLIED

o110H lll HM11111111|1111111111111111 mm1

I TI11-1S. +100) IIIIIIIIIII (*R. .J.Vur1111= . - n 11 11 1 1 111 I I111

I. . . ......... 1 11 .. t _._

V-I

^_v^st W AFD BAND

i 1 0

-11111

.. . . . . . . . .. . . . . ... . ..H . _ . . . _. . . .. . . . . . .. . . .. . . . . . .

I ilt! 1IHIIIIIIIII IIII 1 H I l'U I I I I PUI+. |Fs I5

I I N I I I I -------- n t: . .. . . . .

11111111111. 11. ... . .. .....

50

-30 .*50- - -- - -- -40Ll1 11 tt [..111111111

j:;-,

I -

* -100 OR AO()

APD () I

,5 , 5

_V . , - -,_ _ f _

-70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70

PERIPHERAL ASI * -100 / AO () / AD (%)

BNFL Slide 42

WesthighouseBNFL Slide 42 O@Westinghouse

RAOC Condition I

* RAOC EVALUATION (continued)a, c

GBNFL Slide 43 BdWestinghouse

RAOC Condition I

FIGURE 1

ST LUCIE UNIT 2 CYCLE 13AO and AFD BAND COMPARISON8% ASI UNCERTAINTY APPLIED

FIGURE 2

ST LUCIE UNIT 2 CYCLE 13AO and AFD BAND COMPARISONNO ASI UNCERTAINTY APPLIED

1101 110 l111 111111 11111 11111 II III III 11 1111111 IIIIIII1 l iii

Illlllrl~lllll!-------- =lllll1llll!!l100 l -23.100 4 I(+8. 4

n _f jj ZUU

_ 90

:

9 80

70-, -0

.. . . . . . . . . . . . . .I _ _ I -I ... v [I§ l | x I ...... .| T T |

a.0Ia-

90;

bsU

. I I I I 14 1 1 1 1 1 1 1 ....................11'd11-11ASI * -100 OR

A - - -AFD (I

AO (W)-'U 111111 . 11

1(-50 -+6S) ASI * -100 OR

AFD M%)

A (1 .651,0,.ril..,,-,--

. . .. . . . . . .

izni I I I 1 1 l l r l [ 2 __ ji =6u11 11 1 11 1 II II I II II II I I II II

5bU

.. . ... . . . . .

4C11 _ m IIIli 1r 11 ~l~ l rIII IIINIIII I I II 1 l il H I II III III -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70

PERIPRAL ASI * -100 AO %) / MD (I)

-70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70

PERIPMAL ASI * -100 / AO 00 I AJ D V

* BNFL Slide 44 Westinghouse(DBNL Slide 44 (SWestinghouse

RAOC Condition I

* RAOC EVALUATION (continued)

- Each axial power shape analyzed to determine if the linear heat rate

constraints are met

a, c

BNFL Slide 45 SeWestinghouse

RAOC Condition IFIGURE 5

ST LUCIE UNIT 2 CYCLE 13MAXIMUM LINEAR HEAT RATE VS CORE HEIGHT

(-0.16, +0.23 ASI BAND)8% ASI +2% CLOR UNCERTAINTY APPLIED

FIGURE 6ST LUCIE UNIT 2 CYCLE 13

MAXIMUM LINEAR HEAT RATE VS CORE HEIGHT(-0.08, +0.15 ASI BAND)

0% ASI +2% CALOR UNCERTAINTY APPLIED

I14. to o, 3..0 I(12.0, 13.0 I

...........

13.0

12.0

11.0

10.0

9.0

8.0

7.0

6.0

+

-

'-

SX

z

15.

14. p 0.0, 13.0 (12.0, 13.0 I

13.0

12.0

11.0

10.0

9.0

8.0

7.0

6.0

5.o

4.0

100% -

100 -

70% FAC POWERSa

50% FAC POWERS

100% - 70% FAC PC015.01

KJERS Eii::.: -- . - -

- 50% FAC PC4.0

3.0 3.C

2.0 2.0

1.0 I0 1 2

BOTTOM

3 4 5 6 7 8 9 10 11 121 . 0r-t -- tf

0 1 2

BOTTOM

3 5 6 7 8 9 10 11 12

CORE HEIGHT (FEET) TOP CORE HEIGHT (FEET) TOP

OBNFL Slide 46 (sWestinghouse

RAOC Condition IFIGURE 7

ST LUCIE UNIT 2 CYCLE 13MAXIMUM LINEAR HEAT RATE VS CORE HEIGHT

(ASI BAND COMPARISON)INCLUDES 2 CALORIMETRIC UNCERTAINTY

15.0

14.O ( 0., 130 I(12.0. L3.0 )

13.0

12.0

11.0

10.0

9.0

8.0

7.0

S.0

4.0

-0.16, +0.23 ASI BAND-. - - -

).08, +0.1!I AS I BAND

3.0

2.0

1.01:0 1 2 3 4 5 6 7 8 9 10 11 12

TOPBOTTOM CORE HEIGHT (FEET)

DBNFL Slide 47 SeWestinghouse

RAOC Condition I

Conclusions - Condition I RAOC Evaluations- Feasibility for implementing RAOC in future cycles for St. Lucie Unit 2

confirmed- Results are as expected- T/H design has confirmed acceptable DNB results for verification of linear

heat rate LCO should the incore detectors become inoperable- A change in the Axial Shape Index (ASI) breakpoints from 65% power to

50 % power will be proposedReduces degree of bowing in AFD space while allowing sufficientdegree of operational flexibility


RAOC Condition II

* Standard Westinghouse Condition I accident studies performed- Cooldown transients- Control rod withdrawal- Boration/Dilution

* Note: Manual rod control only - no automatic rod withdrawalcapability in St. Lucie Unit 2

GBNFL Slide 49 Westinghouse

RAOC Condition I

FIGURE 8ST LUCIE UNIT 2 CYCLE 13


CONDITION II - ROD MALFUNCTION

i14IE994

w

9zm0

x

i

5

IR

17.0

lS n

I ;

1A

13.0

12 .

FIGURE 9ST UCIE UNIT 2 CYCLE 13


CONDITION II - BORATION/DILUTION

17. ... T.I.0....

1 4 .0 T I... . . .. . . . . . 50 P

12.0 ,,.,_G TT7 _

> l8 i0 II 1111 &

B 1.0 A- 111.__AW B s~~o 4 lNTITIO FRO 70i PWER4w

4.0 ....... INITIATION FROM 10% POWER

11.

A1A

4

7

0 1 2

BOTTOM

4 5 6 7 8 9 : I.0 11 12TOP

0 1 2 3 4 5 6 7 8 9 10 11 12

BOTTOM CORE HEIGHT (FEET) TOPCORE HEIGHT (FEET)

* BNFL Slide 50 �Westinghouse(BNFL Slide 50 (sWestinghouse

RAOC Condition II

* Conclusions - Condition 11 RAOC Evaluations- Feasibility for implementing RAOC in future cycles for St. Lucie Unit 2

confirmed- Results are as expected - Comparisons to sister Turkey Point Units show

similar behavior- Ample margin exists to limits


1 ---- 7

Section 6T/H - Code, Core Limits, Correlation

I S (BNFL Slide 52 (OWetinghouse

OutlineT/H Analysis Approach

ABB-NV with VIPRE

St. Lucie 2 VIPRE Model

Revised Thermal Design Procedure (RTDP)

* Core Thermal Limits for TM/LP Trip

RAOC Power Shape DNB Verification

Accident Statepoint Analysis

BNFL Slide 53 O)Westinghouse

T/H Analysis Approach

• Utilize NRC-approved bounding evaluation results, not impacted by WCAP-9272, for St. Lucie 2 core and CE-type fuel

- Engineering hot channel factors- Core parameter and peaking factor uncertainties, etc.

* Apply NRC-approved code and method- Westinghouse version of VIPRE-O1 (VIPRE)- Revised Thermal Design Procedure (RTDP)- ABB-NV DNB correlation

Adjustment to existing design process- Core thermal limits for TM/LP- RAOC power shape verification

BNFL Slide 54 OWestinghouse

CE-ABB DNB Correlation

* CE-ABB DNB correlation (CENPD-387-P-A)- ABB-NV for 1 4xl 4 & 1 6xl 6 non-mixing vane fuels- ABB-TV (1 4x1 4 Turbo only)

* Qualification with VIPRE submitted to NRC- Addendum 1 to WCAP-1 4565-P-A (June 03)- VIPRE equivalent to TORC for DNBR calculations- Current 95/95 DNBR limit of 1.13 remains unchanged- Current applicable range remains valid

(BNFL Slide 55 c)Westuighouse

St. Lucie 2 VIPRE Model

One-pass model (WCAP-1 4565-P-A)- Core & hot channels modeled in one calculation- Applicable to CE-type PWR cores- Designated hot channels and locations- Model considers hydraulic loss due to core plates

* Bounding power and flow distributionsa, c

BNFL Slide 56 d 5Wetinghouse

VIPRE 25-Channel Model (1/8th HA)a, c

BNFL Slide 57 S eW estinghouse

VIRPE 25-Channel Model (1/8th Core)a, c

*BNFL Slide 58 �WestinghouseBNFL Slide 58 (OWesinghouse

Revised Thermal Design Procedure (RTDP)

• RTDP (WCAP- 1 397-P-A) is similar to current ESCU- Statistical DNB design method- Applied to most Westinghouse plants including Turkey Point- Current uncertainty values remained unchanged

* Uncertainties to be convoluted for 95/95 DNBR limit- Core parameters- Hot channel factors- Engineering manufacturing tolerances- DNB correlation, subchannel and transient codes

OBNFL Slide 59 (OWestinghouse

RTDP Application

St. Lucie 2 application in compliance with SER conditions

* RTDP DNBR limit verified and applied at DNB limiting conditions- Loss of flow & seized rotor (locked rotor)- Pre-trip steamline break (HFP SLB)- CEA withdrawal at power (rod withdrawal)- CEA drop and static rod misalignment, etc.

* RTDP not used- Hot zero power steamline break- CEA withdrawal from subcritical

*BNFL Slide 60 S eWestinghouse

Core Thermal Limits for TM/LP Trip

* Input for TM/LP trip setpoint confirmation

* Core Thermal Limits: T-inlet vs. Power- DNBR

- ABB-NV maximum quality

- Vessel exit boiling

- At different pressure levels

* AT-inlet vs. (-ASI) limit accounts for axial shape effectsI a,c

BNFL Slide 61 GWestinghouse

Axial Power Shapes for DNB Analysis

* Reference axial power shape for HFP RTDP events- Loss of flow, seized rotor, dropped rod, etc.- Based on nominal operating range & conditions (Condition I)- Affected by ASI operating limits in Fig. 3.2-4 of COLR

• Accident shapes for TM/LP Trip- Reference AT-inletvs.ASI limit- Condition II RAOC shapes

• Accident specific power distributions- Steamline break- HZP events

, BNFL Slide 62 OWestinghouse

Accident Statepoint Analysis

VIPRE transient calculations- Model and method consistent with WCAP-1 4565-P-A- Fuel rod model initialized with FATES temperature data

* DNB limiting accidents to be analyzed:- Loss of flow- Seized rotor

- Steamline break- RCCA malfunction, etc.

(DBNFL Slide 63 OWestinghouse

Summary

* ABB-NV has been validated with VIPRE

* St. Lucie 2 VIPRE model consistent with WCAP-1 4565-P-A

* DNBR limit for transient analysis statistically determined using RTDP

* Core limits define DNB basis for TM/LP trip setpoints

* RAOC power shape verification is conducted on cycle-specific basis

* Accident analysis similar to those for other PWR

*BNFL Slide 64 WestinghouseBNFL Slide 64 (OWestinghouse

I

Section 8RETRAN Model

I BNFL Slide 65 O Westinghouse

(BNFL Slide 65 OWestinghouse

RETRAN Code

* No Code Changes Are Required to Support the St Lucie 2 ModelImplementation

BNFL Slide 66 Westinghouse(BNFL Slide 66 (sWestinghouse

St. Lucie 2 RETRAN Model

Changes made to:- Nodalization- Control/Protection Systems

No new code options are implemented in the St. Lucie 2 Model that were notaddressed in WCAP-1 4882-P-A ("RETRAN Modeling and Qualification forWestinghouse Pressurized Water Reactor Non-LOCA Safety Analyses")

*BNFL Slide 67

(BNFL Slide 67 (Weslinghouse

St Lucie 2 RETRAN Model

* Although the SER for WCAP-1 4882 limits the applicability of the WCAP to

Westinghouse designed PWRs, many portions of the WCAP are equally

applicable to the CE model developed for St. Lucie 2- The modeling options described in WCAP-1 4882 are equally applicable to

the St. Lucie 2 model- The SER limitations discussion in WCAP-14882 are equally applicable to

the St. Lucie 2 model

*BNFL Slide 68


St Lucie 2 Reactor Coolant System

0 The changes made for the CE design for St. Lucie 2 include: a, c

0

lOther change made:

La,c

*BNFL Slide 69 WestinghouseGBNFL Slide 69 O)Westinghouse

RCS Diagrama, c

BNFL Slide 70 �We�tinghouseGBNFL Slide 70 oWeinghouse

Vessel Diagram'I a,c


(BNFL Slide 71 (OWestinghouse

Steam Generator DiagramI a,c

OBNFL Slide 72 BWemtinghouse

St. Lucie 2 RETRAN Model Changes

Control/Protection System Changes compared to WCAP-1 4882-P-A Model

- Except for RCS flow measurement, sensors and sensor locations are similar

- Actions that can be implemented (reactor trip, safety injection, valve

opening/closing, etc.) are effectively the same- Processing of the sensor protection signals is different- Basic control system layout is similar to Westinghouse models

BNFL Slide 73 9We�tinghouseBNFL Slide 73 Westinghouse

St. Lucie 2 RETRAN Model Changes

Protection System modeling reflects St. Lucie 2 specific design, including:- RCS Flow measurement based upon steam generator delta-P- Reactor trip functions

* Variable High Power* Thermal Margin Low Pressure** Start-up Rate* Local Power Density** Asymmetric SG Transient* Low Flow* High Pressurizer Pressure* Low SG Level* Low SG Pressure* Turbine Trip

* User-defined ASI vs Time


St. Lucie 2 Control/Protection Modeling

* High SG Level- Shut FW Reg. Valve for Affected SG

* High-High SG Level- Turbine Trip

- Trip FW Pump(s), Close MFW Pump Discharge Valve(s)

*BNFL Slide 75 GJ Westinghouse(BNFL Slide 75 Westinghouse


CE Unique Reactor Trips- Thermal Margin Low Pressure (similarto OTAT)- Variable High Power (automatically reduced for downpower transients)

- Startup Rate Trip (Decades/minute - similar to PFRT trip)

- High Local Power Density Trip (ASI dependent)

* Low Steam Pressure- Reactor Trip (No SI)- MSIV / MFIV Closure (Separate Setpoint)

* Low SG Level- Reactor Trip- AFW initiation to Affected SG only

@>BNFL Slide 76 Westinghouse


Safety Injection- Initiates on Low Pressurizer Pressure Only- Starts Sl System- Starts Diesels- Limits PZR Heater Capacity

Low Flow Reactor Trip- Based on total of the two SG AP signals

(BNFL Slide 77 S eWestinghouse

Section 9Steamline Break

, . ,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~L-'m"BNFL Slide 78 SeW estinghouse

Pre-Trip SLB (HFP)

* RETRAN model developed

* Based on available protection systems and expected effects of the transient,the basic range of sensitivities were investigated.

- Inside and Outside Containment- Varying MTC- With and without offsite power- Break size

• Acceptance criteria- Peak linear heat rate- DNBR


Pre-Trip SLB - Analysis methods

The following trip functions are modeled:- Variable High Power reactortrip (including excore neutron detector power

signal and thermal power calculation)Effects of RPV downcomer density changes on the excore detectorsare specifically modeled

- Low Steam Generator Pressure reactor trip- High Containment Pressure reactor trip (Inside Containment breaks);

although available, not used

(3BNFL Slide 80 OWestinghouse

Pre-Trip SLB - Expectations/Conclusions

Large breaks must satisfy ANS Condition IV acceptance criteria, which allows

fuel failure

• All breaks expected to satisfy ANS Condition 11 acceptance criteria

* Results of sensitivity studies demonstrate that plant specific analyses should

analyze:- Inside containment- Most Negative MTC to produce trips on thermal power AT and low

steamline pressure- Without offsite power- Spectrum of break sizes


Pre-Trip SLB - Heat Flux as a function of Break Size and MTCa, c


(DBNFL Slide 82 Oestinghouse

Pre-Trip SLB - Nuclear Power: 2.5ft2 break vs 3.2 ft2 break

C

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*BNFL Slide 83 S eWestinghouse

Pre-Trip SLB - Heat Flux: 2.5 ft2 break vs 3.2 ft2 break

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*BNFL Slide 84 Wetinghouse

Pre-Trip SLB - Pressurizer Pressure: 2.5 ft2 vs 3.2 ft2 break

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BNFL Slide 85 (dWestinghouse

Pre-Trip SLB - Vessel Inlet Temps: 2.5 ft2 vs 3.2 ft2 break

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Pre-Trip SLB - SG Pressure: 2.5 ft2 vs 3.2 ft2 break

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*BNFL Slide 87 G Westinghouse

Pre-Trip SLB - SG Loop Steam Flow: 2.5 ft2 vs 3.2 ft2 break

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OBNFL Slide 88 OWestinghouse

Pre-Trip SLB - DNBR: 2.5 ft2 vs 3.2 ft2 break

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4

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1.5

*BNFL Slide 89 WestinghouseBNFL Slide 89 Wetinghouse

Post-Trip SLB (HZP)

* Transient is very similar to typical Westinghouse transient, except that LSPdoes not invoke a Safety Injection (use LPP instead)

* Analysis assumes offsite power available- Low flow case (without offsite power) has historically been non-limiting

with respect to the SLB case with offsite power available based on WCAP-9226-P-A, Rev 1. CE plant design does not present any uniquecharacteristics that would prevent similar behavior

- Confirmed through developmental analysis for St. Lucie* Iterative process with Core Design to achieve conservative reactivity swing* The analysis will demonstrate that the DNB design basis is satisfied

0BNFL Slide 90 Westinghouse

Post-Trip SLB (HZP Trip): SG Pressure

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* Slide 91 Sd9Westinghouse

Post-Trip SLB (HZP Trip): Steamline Break Flow

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*BNFL Slide 92 OWestinghouse

Post-Trip SLB (HZP Trip): Pressurizer Pressure

200

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GBNFL Slide 93 SeWetinghouse

Post-Trip SLB (HZP Trip): Vessel Inlet Temperatures

550

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BNFL Slide 96 S 9Westinghouse

Post-Trip SLB (HZP Trip): Core Reactivity

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BNFL Slide 97 �Westinghause(BNFL Slide 97 (OWestinghouse

Section 9aPost Trip Steamline Break Analysis

(Hot Zero Power with Loss of Offsite Power)

L- I

GBNFL Slide 98 Ostfinghouse

Introduction

* Case without (w/o) offsite power is characterized with low RCS flow- Core power driven natural circulation- Requires detailed crossflow calculation in reactor core

* WCAP-9226-P-A, Rev. 1 conclusion re-validated for St. Lucie 2- Case with offsite power bounds case w/o offsite power- No change to analysis approach or method

BNFL Slide 99


Validation Process

Accident statepoints from RETRAN- For both cases with or w/o offsite power- Loop temperatures and flows, pressure, core boron, power vs. time

Power distributions from SPNOVA/VIPRE- At DNB limiting time step- Additional reactivity check with RETRAN at other time steps

DNBR calculation using VIPRE- Subchannel model- W-3 and McBeth DNB correlations for low flow/low pressure


SPNOVA/VIPRE Coupling

* SPNOVA/VIPRE coupling described in WCAP-1 5806 (SER issued in 07/03)

- Executed in either steady state or kinetic mode

- SPNOVA static neutronic solution consistent with ANC

- Same nodes between SPNOVA and VIPRE- Auxiliary program ANCKVIPRE coordinates data transfer

* Data interface similar to previous calculations for WCAP-9226- 3-D core power distribution from SPNOVA to VIPRE- Coolant density and temperature from VIPRE to SPNOVA

- VIPRE fluid solution accounts for cross flow effects

*BNFL Slide 01 OWeing~house

Validation Results_ a,c

* Results and conclusions consistent with WCAP-9226-P-A, Rev. 1

* McBeth DNB correlation also shows similar conclusion

BNFL Slide 102 �WestinghouseBNFL Slide 1 02 westinghouse

I

Section 10Asymmetric Steam Generator Transient

IBNF- SIBNFL Slide 1 03 CWestinghouse

ASGT

* ASGT is an event that causes a rapid imbalance in heat transfer between the

two SGs

* Initiated by one of the following:- single MSIV closure- feedwater flow reduction to one SG- excessive feedwater flow increase to one SG

* The rapid rate of closure of an MSIV results in the most rapid temperature tiltacross the reactor core

9BNFL Slide 104 Wesfighouse

ASGT

ASOGT is classified as an ANS Condition 11 event

* ASGT event is primarily analyzed to ensure that the DNBR SpecifiedAcceptable Fuel Design Limit (SAFDL) is satisfied

* Reactor protection provided by High Steam Generator secondary pressure APreactor trip (functionally a part of the TM/LP trip)

*BNFL Slide 105 �We�tinghouseCBNFL Slide 1 05 (Wstinghouse

ASGT

* .Since ASGT is being analyzed with respect to the DNB related acceptancecriteria, the analysis will be treated as a typical Westinghouse Revised ThermalDesign Procedure (RTDP) analysis

- Measurement uncertainties are incorporated in the DNB correlation

* Parametric studies on SG tube plugging level have been performed

BNFL Slide 106 Westinghouse(DBNFL Slide 1 06 O)Westinghouse

I

Section 1 1Feedline Break

(BNFL Slide 1 07 Westinghouse

Feedline Break

Typical Analysis methodology for Westinghouse plants provides FSARChapter 15 documentation on the long term heat removal capability of theAFW System

- Cases performed both with, and without, offsite power- Overpressurization bounded byTurbineTrip (Condition 11) event- Fuel failure/dose bounded by SLB (for FLB)

Current St. Lucie Unit 2 analysis methodology analyzes foroverpressurization, fuel failure, and dose

- Long term heat removal addressed in FSAR Chapter 10- Feedline break is a limiting overpressure event due to methodology

applied

@(BNFL Slide 108 Westinghouse

Feedline Break

Analysis Methodology to be implemented:- Leave the St. Lucie Unit 2 Chapter 10 analysis methodology

intact/unchanged- Use Westinghouse Chapter 15 arguments as to bounding events for fuel

failure/dose- Address overpressurization for FLB through analysis with typical

Westinghouse assumptionsAssume the feedring does not fall on the tube sheet


I 7 - :

Section 1 2Documentation Expectations

II BNFL Slide 110 0 Westinghouse(BNFL Slide I110 Westinghouse

Documentation Expectations

. Submittal- Typical licensing submittal format

* Descriptions of analyses (key assumptions, criteria, codes & methods,

etc). FSAR updates* 50.92 for proposed Tech Spec updates

* Schedule- January 2004

*BNFL Slide 111

�Westinghouse(BNFL Slide I111 (OWesinghouse

Production Activities

* Overview & Discussions

* Questions

*BN WestinghouseSlide II12

I

A BNFL Group company

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