ML20207A755

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Summary of 861022 Meeting W/Util in Bethesda,Md Re Selection of Axial Power Shape for Large Break LOCA Analysis.List of Attendees & Supporting Documentation Encl
ML20207A755
Person / Time
Site: Maine Yankee
Issue date: 11/04/1986
From: Sears P
Office of Nuclear Reactor Regulation
To: Thadani A
Office of Nuclear Reactor Regulation
References
NUDOCS 8611110257
Download: ML20207A755 (35)
v • d • e


Text

. _ . _ _ _ __ _ ._- _ __ . _. _ _ _ _ _ _. .

Novemb3r 4, 1986~

MEMORANDUM FOR: Ashok C.-Thadani, Director PWR Project Directorate #8 Division of PWR Licensing-B l

FROM: Patrick M. Sears, Project Manager i

PWR Project Directorate #8

~

uivision o: rwrt i.iciens ing o

SUBJECT:

SupMARY 0F MEETING HELD ON OCTOBER 22, 1986 CONCERNING MAINE YANKEE,LARGE BREAK LOCA ANALYSIS AXIAL POWER SHAPE '

The meeting was held in Bethesda, Maryland. Those who attended are listed in Enclosure 1. ,

Maine Yankee described in more detail information previously given the staff in a telecon on September 2, 1986,.and a~ meeting with the staff held. September 9, 1986 regarding the incorrect axial power distribution used in Maine Yankee's ,

Large LOCA Analysis.

Maine Yankee provided,the staff with the following information and plan of action:

~

' 1. Selection of Core Axial Power Shapes (Enclosure 2)

2. . Selection of. Modified: Injection delta P (Enclosure 3)
3. Revision to YAEC. Steam Cooling Model'(Enclosure 4)  ;
4. Cycle 10 Analysis (Phase I)-(Enclosure 5) _

j 5. Cycle 10 Analysis'(Phase II) (Enclosure 5)

Regarding Phase I, Maine Yankee proposed a submittal of axial power shapes'and injection delta P;for staff review November 3, 1986, and expressed hopefulness for staff response-(SE) by December 3, 1986. The staff will follow up with Maine Yankee as to the ability.of the staff to provide a SE by December 3, 1986.

-This date is based on a Cycle 10 restart in April 1987.

~

i' -

Regarding Phase II, Maine. Yankee proposed a meeting with the staff in mid-December to present a revised steam cooling model and receive staff comment. Following this meeting, Maine Yankee would submit the model change February 1,1987 and receive the SE from the NRC (Maine Yankee's proposed target-date) May 1, 1987. This-date was desired to eliminate late cycle operating i restrictions imposed by current LOCA onalyses and axial shape limitations.

- Maine Yankee also discussed submittal of a proposed change to the Technical Specifications which would allow removal of certain cycle specific parameters

! in exchange for references to methodology. The staff was unable to be encouraging about the prospects for approval of such a submittal.

i 8611110257 861104 Y PDR ADOCK 05000  % Patrick M. Sears, Project Manager P PDR -

PWR Project Directorate #8 Division of PWR Licensing-B

Enclosures:

As Stated cc w/ enclosures: See next page PBD# PD # PBD#8 RS P >

PJW er RPerfetti;cf PSears AThad'Ani 11/3 /86 11/4/86 11/t/86 11/ W86 11 /86

' . -y- --i-- wy,- , - - w e r r, --Wr-*-+r--,=-=5 -=-w.- -e, w.++-y--r-

bf MEETING SUMARY DISTRIBUTION LIST 88-d/}

PWR PROJECT DIRECTORATE #8 l

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NRC PDR L PDR PBD#8 Rdg PKreutzer OELD EJordan I l

BGrimes ACRS-10 NRC Participants RPerfetti r RCJones NLauben DFieno AThadani PSears i

f l

Enclosure 1 LIST OF ATTENDEES MEETING HELD ON OCTOBER 22, 1986 MAINE YANKEE ATOMIC POWER COMPANY NAME ORGANIZATION Renee M. Perfetti NRC/PWR-B, PBD-8 Robert C. Jones NRC/PWR-8, RSB Norm Lauben NRC/PWR-8, RSB Cecil-Thomas NRC/PWR-B, RSB Daniel Fieno NRC/PWR-8, RSB Ashok Thadani NRC/PWR-B, PBD-8 George M. Solan Yankee Atomic - Reactor Physics Stephen P. Schultz Yankee Atomic - LOCA Stephen D. Evans Maine Yankee Keith B. Spinney Yankee Atomic - Reactor Physics Peter L. Anderson Yankee Atomic, Project Manager for MY Ausaf Husain Yankee Atomic Electric Company, LOCA Group Manager ,

Jamal Ghaw Yankee Atomic Electric Company, LOCA Group Manager Howard F. Jones, Jr. Maine Yankee Atomic Power Company Ross Jensen Yankee Atomic Electric Company

Enclosure 2 l NEINE YANKEE AXI AL SilAPES FOR LOCA ANALYSIS EVALUATION OVERVIEW g e' TYPICAL AXIAL POWER SHAPES O NOMINAL TULL POWER SHAPES O XENON OSCILLATION SHAPES LIMITS ON AXIAL POWER SHAPES DUE TO LCO'S 0 SYMMETRIC OFFSET LIMITS O RADIAL PEAKING LIMITS O LOCA LIMITS CLASSES OF AXIAL POWER SHAPES O CLASS 1 - HICH POWER UP TO PEAK LOCATION O CLASS 2 - HIGH POWER TROM PEAK TO PCT LOCATION MATHEMATICALLY-DEFINED AXIAL SHAPES O INCENTIVES

. O ASSUMPTIONS O TYPES OF AXIAL SHAPES O COMPARISON TO POSSIBLE AREA OF PEAK POWER SHAPES

6 d

MAINE YANKEE TY."lCAL A !AL "0W"R  ::A?";

LOW-LEAKAGE RELOAD CORES NOMINAL FULL-POWER SHAPES O ALL NEAR-LIMITING ASSEMBLIES ARE FRESH O FRESH ASSEMBLIES START WITH TLATTENED COSINE SHAPES t

. - BOTTOW-PEAKED IN LOW BURNUP REGIONS

- SYINETRIC IN MEDIUM BURNUP REGIONS

- TOP-PEAKED IN HIGH BURNUP REGIONS O FRESH ASSEMBLIES BURN TO

- FLATTENED BOTTOM-PEAKED SHAPES

- MILDLY DOUBLE-HUMPED BOTTOM-PEAKED SHAPES O RELATIVE POWER AT HIGHER AXIAL ELEVATIONS INCREASES WITH CYCLE BURNUP XENON OSCILLATION CASES O AXIAL XENON OSCILLATION CASES ARE GENERATED FOR SYMMETRIC OFFSET DEPENDENT RPS SETPOINTS O THESE CASES PRODUCE THE HIGHEST AXIAL PEAKINGS

~

MY CYCLE 10 NORMALIZED RXIN POWER VS. % CORE E!GHT

' WP, ARO EOUILIBRIUM CONDITIONS i..

i+ -

lI ill +!+ +-- ----

i+- lll +H- +R l

+H- +Hg$Wr7P3% +f

! '' 4- /# +FF M9 m

' ' 7 '

+F/f& +-- l l  ;  % l TSSE8u g [.4EM&-

8 l ll h-- EdJ M[Qk% y'CYCLEEXPOSURE REGION E'

y --h 3 T

~~~ -'~~~

'h~

6.00 GWD/MT M

c.s is ,

i  ;

i Mg&

i 10.00 GWD/MT 13.00 GWD/MT

~ - -

-N \(- q i

I li it i e iti I I I o.3

.-H- +H- -i+ ++ -H+ ++ l e to ao 30 to so ao 70 so so 100 PERCENT CORE E IGHT I

'[++ill l

I l

I l t if II lll ill III ll It II I ll il iI 1.2 8

++ '

! *# 'l;

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~~

i I  ! UM E g%{!8 , 'l --y lll Q-- BURNUP "I

Y CYCLE EXPOSURE w

~

- .05 GWD/MT i i

i/ i iN l- ll N .: - 2.00 GWD/NT i A c.e 6.00 GWD/MT

--k 3v i c.s

YT1 10.00 GWD/MT

~-

l

--+ ---

i i i ,, 13.00, GWD/MT

, , , --+ - i o.3

.-+ -H- +H- +H- --+ ++

to . 30 to . . Fo

-+ so l

. 1 o

PERCENT CORE E IGsT

+- -+- lii -+- +H- +-

i..

+F- ll ll --+ +H- +--

l l ll l ll +.+ M +H 44 'P Aj ----

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IN HIGH

~ c.e ,

BURNUP E g 3g g- ll l 1 -- . - -- ---- ----

(--- REGION

-h h Y .05 GWD/MT

~

CYCLE EXPIMiURE 8'*7 i 4~~

is nKi -

t i

/ ~

i l l'(6 xx 2.00 GWD/MT 1 t o.e 6.00 GWD/MT ,

, ix x -

; i xy 10.00 GWD/MT 13.00 GWD/MT T-~

o.5

-+- +-- i , ,,, i i

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c , . . . . . . .

PERCENT CORE EIM l - - ,.-- - - - - - - - - - _ _ _ . . _ , _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

. MY CYCLE 10 NORMALf2ED AXIAL POWER VS. PERCENT CORE HEIGHT XENON OSCILLATION CASES, POSITIVE SY}0!ETRIC OFFSET 1.s j 85 p m l FMMW 1

///  %%

- g,//- / - - ~ -.M g-1.0 o.e fyf 3 g .BEGINNING ffjp (g 0F CYCLE Y *

M/\ \ \\

i ///\ \\ U "j M \ \\ CASE 10 OrrSET 3 I

'i

[ [/\ \\ \ l-- B310RR31 .166  %

i c.3 ff gg g"- B310RR32 B690RR31

.168

.198 c.a

[ \ '

B690RR32 .198 B160RR32 .208 c.1 0.0 - . - - - - - -

PERCENT Or CNE HEIGHT 1.5 3'

?

g ,

i -

p _ xN

. i. -

ff 7 g

'l /// M MIontE 2( \\ OF CYCLE m # i \\

y /JX \ \ :L Q * f A\ \\ \

g o'5 / # \\ \\

CASE 10 0FTSET

[/,Oe \ \\b- M760RR32 .125 c.s ff \h \ L--- M760RR31 M170RR31

.125

.145 j o.2 I

\ \

M170RR32 .145 M340RR31 .177 0.1

, a no w so go so so yo so so too

, PERCENT Or CORE lEIGHT 1.8 '

1.5 1.4 g ,

8' 9 f f  %

1

f f %N g ff  %\ END g*2*** gg \\ OF CYCLE A \ \\

E '#

// i \  %

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0.4

/ // \\ '\ \l- E785RR32 .168

/ pr gg' \'- E785RR31 .168 c.3

  • E355RR31 .174 l

c.2-

[ \b- E355RR32 .174

.197 E180RR31 c.t o.o - -

PERCENT F CME FEIGHT

MAINE YANKEE LIMITS ON AXIAL POWER SHAPES DUE TO LIMITING CONDITIONS FOR OPERATION (LOO'S)

SYlWETRIC OFFSET LIMITS O SYMMETRIC OFFSET LIMITS AS A TUNCTION OF POWER ARE MONITORED BY THE EXCORE DE'?ECTORS AND CONSTITUTE AN LCO O SUWWETRIC OFFSET LIMITS NEAP FULL POWER DEFINE AN ENVELOPE OF ACCEPTABLE TOP-PEAKED AXIAL POWER SHAPES VERSUS CORE HEICHT FOR LOCA EVALUATION RADIAL PEAKING LIMITS O RADIAL PEAKING LIMITS ARE MONITORED BY THE FIXED INCORE DETECTORS AND CONSTITUTE AN LCO O RADIAL PEAKING LIMITS DEFINE THE MAXIMUM ALLOWABLE INTEGRATED POWER IN THE FUEL ROD O THE MAXIMUM RADIAL PEAKING FACTOR AND ALL UNCERTAINTIES IN TECHNICAL SPECIFICATIONS ARE APPLIED TO MAXIMlZE THE INTEGRATED POWER IN THE FUEL PIN LOCA LIMITS O LOCA LIMITS ARE MONITORED BY THE FIXED INCORE DETECTORS AND ALARM SYSTEM AND CONSTITUTE AN LOO O LOCA LIMITS DEFINE THE MAXIMUM ALLOWABLE LINEAR

~

HEAT GENERATION RATE (LHGR) AS A FUNCTION OF CORE HEICHT O LOCA LIMITS AND ALLOWABLE AXIAL SHAPES ARE DETERMINED ITERATIVELY FOR A FIRST- TIME ANALYSIS

MAINE YANKEE CYCLES 8,9, AND 10 ENVELOPE OF AXIAL POWER SHAPES FOR NEAR UMmNG ASSEMBUES TOP PEAKED SHAPES FROM ZERO SYMMETRIC OFFSET TO POSITNE SYMMETRIC OF1 st.I UMITS AT FULL POWER 1.6 -

~~'

1.5 -

'*~

/g@98"'8 $ }o 'fs

\ ,ig Esa'g A

y i 1.3 -

3 4 1.2 - /

agI 1.1 - k b

3 1.0 -

'-[po g t

2 09- I g

g 0.8- /a, 8 gt F 0.7 - i A = CYCLE 8 ^

$ '8 ~ / o = CYCLE 9

$ S o = CYCLE 10 0.5 - A 0.4 -

0.3 -

0.2 -

0.1-0.0 , .

0 10 20 30 40 50 60 70 80 90 10 0 PERCENT OF CORE HEIGHT w - -

1 1 I IE o

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MAINE YANKEE CYCLE 10 AREA OF POSSIBLE PEAK POWER SHAPES .

FOR EVALUATION IN LOCA IMPROVED METHODS 20

^0 IM ODS PO m S .U ITS

~

4 ';: x /  !

B v 15 -

14-h I3~

ER SHAPES Z 12 -

lic V AF

~

RADIAL PEAKING UMITS

/ ' '

/ '

o 1o' 2o 'do ' ' 4'o ' ' do' do 7o' 'do' 'do' 10 0 l PERCENT OF CORE HEIGHT

MAINE YANKEE CLASSES OT AXIAL POWER SHAPES THE LOCA LHCR LIMIT IS JUSTIFIED BY EXAMINATION OT AXIAL SHAPES WITH POWER PEAKING AT SELECTED CORE ELEVATIONS TWO CLASSES OF AXIAL SHAPES ARE EXAMINED TOR EACH ELEVATION. EACH OF WHICH MAXIMlZES A SIGNITICANT CHARACTERISTIC

. CLASS 1 - HIGH POWER UP TO PEAK POWER LOCATION THESE SHAPES MAXIMlZE THE INTERGATED POWER AND ENTHALPY RISE UP TO THE PEAK POWER LOCATION. FLATTENED. SYWETRIC AXIAL SHAPES CHARACTEl:IZE THIS CLASS OF SHAPES CLASS 2 - HICH POWER TROM PEAK POWER TO PEAK CLAD TEMPERA' LURE (PCT) LOCATIONS THE PCT LOCATION IS HIGHER IN THE CORE THAN THE PEAK POWER LOCATION. MAINTAINING HIGH POWER TROM THE PEAK POWER TO PCT LOCATIONS IS ACHIEVED THROUGH TLATTENED. TOP-PEAKED

' AXIAL SHAPES WITH MAXIMUM TOWER AT THE TOP OF THE CORE

MAINE YANKEE j CLASSES OF AXIAL POWER SHAPES

. FOR LOCA ANALYSIS  ;

1.6

! 1.5 - .

' l*4 ' CLASS 1 SHAPE-i CLASS 2 SHAPE -

MAXIMUM POWER MAXIMUM POWER 1.3 - UP TO PEAK FrtOM PEAK TO PCT LOCATION LOCATIONS g_ ' p ................--

s' 1.1- ,/o s, b 1.0 - , PEAK 's' 3 #

LOCATION f O Q.

0.9 - /

/ 's Ld 0.8 - / 's

> / 's Q 0.7- / 's E 0.6 - / PCT 0.5 .

/ LOCATIONS '\

,/ \,

0.4 - / 's

/ \

0.3 -

0.2 -

l 0.1-l 0.0 ...

i. .. .

i i . ..

l 0 10 20 30 40 50 60 70 80 90 100 PERCENT OF CORE HBGHT

i I

l 1

l MAINE YANKEE INCENTIVES FOR I*ATii~.4ATICALLT-

. DETiHED AIIAL SHAFES O SINCE THE MAXIMUM RADI AL PEAKING FACTOR IS USED IN 1HE LOCA ANALYSIS. THE AXIAL PEAKING FACTOR IS THE ONLY FREE VARIABLE FOR ITERATION TO ALLOWABLE LHCR O FAMILIES OF SHAPES MUST BE GENERATED WITH AXIAL PEAKING I

, FACTORS IN THE RANGE OF ALLOWABLE LHCR'S FOR EACH PARTICULAR CORE HEIGHT O TYPES OF SHAPES MUST BE GENERATED WHICH ARE POTENTIALLY MOST LIMITING. THIS IS ACCOMPLISHED BY APROACHING ONE OF MORE OF THE FOLLOWING LIMITS

- POSITIVE SY WETRIC OFFSET ENVELOPE

- MAXIMUM / MINIMUM POWER AT TOP OF CORE

- MAXIMUM / MINIMUM POWER AT BOTTOM OF CORE

- LOCA LHGR LIMIT VERSUS CORE HEIGHT (ITERATIVELY)

O ALL SHAPES MUST BE REALISTIC IN COMPARISON TO NORMAL AND XENON OSCILLATION AXIAL SHAPES

MAINE YANKEE ASSUMPTIONS TOR MATHEMATICALLY-DEFINED AXIAL SHAPES O ALL SHAPES CONSIST OT A COMBINATION OF PARABOLAS AND STRAIGHT LINE SECMENTS O ALL SHAPES ARE NORMALIZED TO THE MAXIMUM INTEGRATED RADIAL POWER INCLUDING UNCERTAINTIES O ALL SHAPES ARE MATHEMATICALLY WELL-BEHAVED (I.E., CONTINUOUS WITH CONTINUOUS DERIVATIVES)

O ALL SHAPES ARE CHARACTERIZED AS CLASS 1 OR CLASS 2 SHAPES TO ACHIEVE THE PARTICULAR OBJECTIVE WITHIN ACCEPTABLE LIMITS l

l

- - - - - - - - _ - - - _ _ _ _ _ _ _ . - y y--9 w

MAINE 7ANKEE TYPES OF MATHEMATICALLY'DEFIN D A:l AL 0::AFC:

FLATTENED SYINETRIC O FLAT STRAIGHT LINE AND TWO PARABOLAS O PEAK LOCATIONS FROM 50 TO 85% OF OORE HEIGHT O TOP / BOTTOM OF CORE POWERS NOT VARIABLE, BUT

, DETERMINED BY NORMALIZATION FLATTENED TOP-PEAKED 0 SLOPED STRAICHT LINE AND TWO PARABOLAS O PEAK LOCATIONS FROM 50 TO 85% OF CORE HEIGHT O TOP / BOTTOM OF CORE POWERS VARIABLE AND SET BY CLASS OF AXIAL SHAPE DESIRED DOUBLE-HUMPED SYnNETRIC O THREE PARABOLAS l 0 PEAK LOCATIONS FROM 70 TO 85% OF CORE HEIGHT O TOP / BOTTOM OF OORE POWERS EQUAL BUT VARIABLE AND SET BY CLASS OF AXIAL SHAPE DESIRED

NORMALIZE 0 AXIAL POWER SHAPES FOR LOCA ANALYSIS PEAK AT S2.08 PERCENT OF CORE HEIGHT CLASS 1 TYPE: FLATTENED SYMMETRIC

  • I I I I I I I I I I I I I 1.3 -

=

f g

}{\ .h A T\\ \

I" /\ \\\ s \

t" / \\\\ \ \

5 0."s / \\\ \\ _ _

T

" 0.5 r

(\) {( PEAKING FACTOR

\\ \\L-1.260

\ ;u- 1:!i8 03 '

1.290 g

0.2 1.300 0.1 O 10 20 30 40 50 80 70 80 90 100 PERCENT OF CORE HEIGHT CLASS 2 TYPE: FLATTENED TOP-PEAKED, HIGH POWER AFTER PEAK 1.4 1.2 pmg 1.1 f

f g AT %s l" A \\ 1 h\\

t" /\ \\\ \ \\\1 E / \\\ \\

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/ ACTOR 1.280 0*3 / \\ L- 1:!$8

[ 1.290 g

0.2 1.300 0.1 0.0 0 10 20 30 40 50 60 70 80 90 100 PERCENT OF CORE HEIGHT

NORMBLIZED RXIRL POWER SHRPES FOR LOCR ANRLYSIS PERK RT 64.58 PERCENT OF CORE HEIGHT CLASS 1 TYPE: FLATTENED SYMMETRIC i.i 1.3 I E X l I AT\ \ l m I A \\\) \ l s[o. .,

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1.210 gl 03 y \ p i:!!8 i y g 1.240 j 0.2 F 1.250 l I 0.1 b 10 20 30 40 50 60 70 00 90 lb0 PERCENT OF CORE HEIGHT CLASS 2 TYPE: FLATTENED TOP-PEAKED, HIGH POWER AFTER PEAK 1.4 1.3 1.2

- M (

!.0 0.9 s" '

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PERKING

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/ \\\---  !:!!8

\ 1.240

[

0.2 1.250 0.1 0.0 0 10 20 30 40 50 60 70 80 90 100 PERCENT OF CORE HEIGHT

NORMALIZE 0 RXIRL POWER SHAPES FOR LOCR ANRLYSIS MAXINUM HEIGHI 0F PERK RT BS.42 PERCENT CORE HEIGHT CLASS 1 TYPE: FLATTENED SYMMETRIC 1.2 1 ~

1.1 _- _-

r mu i I

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.  ! ... W \\ \\L "'"

'1.0e0 E l g 1.070 o,3

\1i {L-- 1.080

,ff \ 1.090 g 0.2 1.100 0.1

~

0 10 20 30 to 50 60 70 80 90 lb0 PERCENT OF CORE HEIGHT CLASS 2 TYPE: DOUJLE-HUMPED SYMMETRIC, HICH POWER AFTER PEAK 1.2 j% 3%

1.0 7 g . -

g

( \\\\\ \

9 Q "7 0.

\\\\,\

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PERKING 0.5 o,,

1.060 1.070 o,3

\l \L---

i 1.080

\ 1.090 0.2 1.100 0.1 0 10 20 30 40 50 60 70 80 90 100 PERCENT OF CORE HEIGHT i

MAlhE YANKEE MATHEMATICALLY-DEFINED AXIAL SHAPES COMPARED TO POSSIBLE AREA OF PEAK POWER SHAPES IMPROVED LOCA METHODS WITH STEAM OOOLING (ESTIMATED LOCA LHCR LIMITS)

CLASS 1- HICH POWER UP TO PEAK POWER LOCATION TLATTENED, SYMMETRIC AX1AL SHAPES TEND TO PROVIDE FOR MAXIMUM UTILIZATION OT POSSIBLE AREA BELOW PEAK LOCATION CLASS 2- HICH POWER TROM PEAK POWER TO PCT LOCATIONS TLATTENED. TOP-PEAKED AXIAL SHAPES WITH MAXIMUM TOP OF CORE POWER AND MINIMUM BOTTOM OT CORE POWER RESULTS IN PCT LOCATION POWERS CREATER THAN THE PRESUMED LOCA LHCR LIMIT LINE CURRENT LOCA METHODS WIYH INJECTION DELTA P (ESTIMATED LOCA LHCR LIMITS)

CURRENT LOCA METHODS LIMITS ARE PROJECTED TO BE SUTTICIENTLY RESTRICTIVE SO THAT TLATTENED, SUWWETRIC SHAPES FULTILL THE REQUIREMENTS OF BOTH CLASS 1 AND CLASS 2 AXIAL SHAPES

MAINE YANKEE CYCLE 10 AREA OF POSSIBLE PEAK POWER SHAPES COMPARED TO FLAT, SYMMETRIC POWER SHAPES 20 -

19-MAXIMUM POWER -

18 LOCA UMITS .,, MAXIMUM POWER -

O IMPROVED METHODS ,

~

, POSITIVE S.O. UMITS

~

Q 16- - - - \ - - - - - /- - - - / m j  %

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j 0 , , , , , , .- , , , , -

0 10 20 30 40 50 60 70 80 90 10 0 PERCENT OF CORE HEIGHT

MAINE YANKEE CYCLE 10 AREA OF POSSIBLE PEAK POWER SHAPES COMPARED TO FLAT, TOP-PEAKED POWER SHAPES WITH HIGH POWER AFTER PEAK 20 -

IS~

MAXIMUM POWER -

18 LOCA UMITS ~% MAXIMUM POWER -

O IMPROVED METHODS  %

, POSITIVE S.O. UMITS U-

.q g 16- - - - g - - - - - /- - - -

e -

s j

's 2

V 35

/  %

/ Nh i 14- f -

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i' O $3 s

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0 10 20 30 40 50 60 70 80 90 100 l

PERCENT OF CORE HBGHT i

l

MAINE YANKEE CYCLE 10 AREA 0F POSSIBLE PEAK POWER SHAPES .

FOR EVALUATION IN LOCA l CURRENT METHODS j 20

' N' MAXIMUM POWER - -

jg. LOCA UMITS MAXIMUM POWER --

O CURRENT METHODS POSITIVE S.O. UMITS

.g 16" T7 - _

l N

l

) k 15-l 14 -

) 13 AREA FOR PEAK POWER SHAPES Z 12 -

p 7- MAXIMUM INTEGRATED Q 6 POWER AREA -

y RADIAL PEAKING UMITS O .

0 10 20 30 40 50 60 70 80 90 10 0 PERCENT OF CORE HOGHT

MAINE YANKEE CYCLE 10 AREA OF POSSIBLE PEAK POWER SHAPES COMPARED TO

! FLAT, SYMMETRIC POWER SHAPES i 20 19' MAXIMUM POWER -

! 18- LOCA UMITS ~,s MAXIMUM POWER -

O CURRENT METHOD $ , POSITIVE S.O. UMfTS j

i

-Q 16- - - - \ - - - - - /- - - -

/

f. -

l v 15 -

\

n y13-

,, -r <

g g \ \

j ':

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l g 10- i g

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4~

3-4 i

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0 10 20 30 40 50 60 70 80 90 100 PERCENT OF CORE HEIGHT I

Enclosure 3 o YAEC LOCA MODEL USED FOR MAINE YANKEE SINCE 1979 o LOST MARGIN DUE TO AXIAL POWER SHAPE-ISSUE o TO GAIN BACK SOME OF THE LOST MARGIN A MODEL

_ IMPROVEMENT IS SUGGESTED o IMPLEMENT A MORE REALISTIC VALUE OF INJECTION AP IN THE REFLOOD MODEL 4

4 4

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a g = o * .5 y o = b 1 2

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$ 0 2

m k =

x &

c 0 E 3 k

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% g =

Y = "

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i 4

TEST PARAMETER AND THEIR RANGES PARAMETER 1/14 SCALE 1/3 SCALE' MAINE TEST RANGE TEST RANGE YANKEE

.. COLD LEG PRESSURE (PSIA) 20,40,60 22,50 37 INJECTION WATER VELOCITY (FT/SEC) PUMPED INJEC. 4,-8, 12 1 - 16 12.87

?

INJECTION ANGLE 90,45 90,45 90 STEAM TEMPERATURE ( F) 350,550 SAT,500 530 -

INJECTION WATER TEMP. 80,120,150 80,120,150 110 i l

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  • Dupitcate Runs

. 1/14 Scale Data  ;

  • 1/3 Scale Data p , , , ,

-0.3 i 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 pV 5 2 INLET STEAM DYNAMIC llEAD.

29 Pressure Loss Due to Pumped Safety Injection

- - Enclosure 4 PM HS BNTATDON OF PROPOSHD MHV:SDON TO VAMC STRAM C00LONG MODHL

. -lNTRODUC flON REVIEW F.XISTING MODEL

-NEW MODEL OBJECTIVES NEW MODEL DESCRIPTION PLANNED JUSTIFICATION FOR NEW MODEl.

CURRENT YABC STRAM C00LONG MODEL FLOW DIVERSION DUE TO BLOCKAGE

! USES A COMBINATION OF EXXON WREM-1 AND WREM-Il DEPENDENT l UPON PERCENT OF BLOCKAGE.

f 1

^

-ilEAT TRANSFER

~

l AN EQUIVALENT STEAM FLOW IS DEFINED SUCH THAT THE HEAT TRANSFER COEFFICIENT (H) CALCULATED USING DITTUS-BOELTER EXACTLY MATCHES THE FLECHT CORRELATION AT THE NODE IMMEDIATELY BELOW THE BLOCKAGE PLANE

-FLUID ENERGY EQUATION G=CRF* GIN *FZ

. WHERE FZ IS DEFINED TO ASSURE CONSERVATIVE RESULT THROUGH AND ABOVE THE BLOCKAGE PLANE

NEW MODEL OBJECT VES

-REMOVE EXCESSIVE CONSERVATISMS PRESENT IN EXISTING MODEL 1 --UTILIZE INFORMATION FROM Fl_ECHT-SEASET IN DEVELOPING AND JUSTIFYING NEW MODEL

-SNflSFY THE INTENT OF APPENDIX K BY COMPUTING THE EFFECT

,OF THE BLOCKAGE UPON THE FLOW AND HEAT TRANSFER

-ASSURE THATTI-lE STEAM COOLING MODEL IS ALWAYS CONSERVATIVE COMPARED TO THE FLECHT CORRELATION

.~ , . -

MODEL DESCR0PT00B0 ASSUf.1PTIONS

-COOLANT FLOW IS SATURATED STEAM

-COOLANT TEMPERATURE IS CONSTANT AT TSAT

-DOMINANT HEAT TRANSFER IS PER FLECHT CORRELATION

-CHANGE IN HEAT TRANSFER COEFFICIENT DUE TO FLOW DIVERSION MUST BE CALCULATED

.. -HEAT TRANSFER ENHANCEMENT DUE TO SINGLE PHASE TURBULENCE WILL BE CALCULATED

-HEAT TRANSFER ENHANCEMENT DUE TO DROPLET BREAKUP WILL BE NEGLECTED FLOW DIVERISION DUE TO BLOCKAGE

-EXISTING MODEL WILL BE USED TO OBTAIN GB/G HEAT TRANSFER H=HFLECHT

  • FT FBu(GD/G)**0.8 (D/DB)**0.2

. FT= TURBULENCE ENHANCEMENT FACTOR CALCULATED USING MODEL FROM FLECHT-SEASET FB'FT < 1.0

MODHL

~

JUSTD FDCATDON THE MODEL WILL BE DEMONSTRATED TO BE CONSERVATIVE WITH RESPECT TO ASSUMING HEAT TRANSFER FROM THE FLECHT CORRELATION COMPARISONS TO RESULTS FROM THE EXISTING MODEL WILL ALSO BE PROVIDED

- - - . ~ - . __ ----n.- . - - . - - - , . , , . - - . - - - - - . , , ----

Enclosure 5

' CYCLE 10 ANALYSIS (PHASE I)

CURRENT METHOD WITH FOLLOWING CHANGES WILL BE UTILIZED o aP PENALTY OF 0.15 PSID BREAK SPECTRUM SENSITIVITY WILL BE PERFORMED o CYCLE 5 RESULTS.WILL BE USED FOR THE BLOW-DOWN PERIOD

- o MODIFIED REFLOOD MODEL WILL BE USED FOR THE REFLOOD PERIOD.

- o WORST BREAK SIZE WILL BE IDENTIFIED B0UNDARY CONDITIONS FOR WORST BREAK SIZE WILL BE USED TO GENERATE LHGR FOR VARIOUS POWER SHAPES RESULTS WILL BE SUBMITTED WITH THE CPAR 90 DAYS BEFORE CORE STARTUP A

AH/ OCT. 22, 1925

CYCLE 10 ANALYSIS (PHASE II)

CYCLE 10 ANALYSIS WILL BE REDONE WITH A REVISED STEAM COOLING MODEL 1

2/1/87 MODEL CHANGE SUBMITTED TO NRC SER FROM NRC 5/1/87 SUBMITTAL OF ANALYSIS 10/1/87 i SCOPE SIMILAR T0 (PHASE I)

SER ON SUBMITTAL 12/1/87

)

i AH/ OCT. 22, 1986 1

-- .. * - - - - - - ' ' " ' ' ' ~ -- " ' ' ' -

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