ML20011A445

Forwards Suppl 2 to Util Reload Application for Cycle 5, in Response to 761029 Request

ML20011A445
Person / Time
Site:	La Crosse File:Dairyland Power Cooperative icon.png
Issue date:	01/17/1977
From:	Madgett J DAIRYLAND POWER COOPERATIVE
To:	Reid R Office of Nuclear Reactor Regulation
Shared Package
ML20011A420	List: ML20011A419 ML20011A424 ML20011A426 ML20011A427 ML20011A428 ML20011A431 ML20011A435 ML20011A437 ML20011A438 ML20011A440 ML20011A445
References
LAC-4440, NUDOCS 8110130361
Download: ML20011A445 (21)

Text

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N.S DK YL.t.%D I*U WL'It 4'00I*L'It.t I% E

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B, Co a,v, 0 0

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54601 J

January 17, 1977 i

In reply, please refer to LAC-4440 DOCKET NO. 50-409 Director of Nuclear Reactor Regulation ATTN:

Mr. Robert W. Reid, Chief Operating Reactors Branch #4 Division of Operating Reactors U. S. Nuc1 car Regulatory Commission Washington, D. C.

20555

SUBJECT:

DAIRYLAND POWER CCOPERATIVE LA CROSSE BOILING WATER REACTOR (LACBWR)

PROVISIONAL OPERATING LICENSE NO. DPR-45 APPLICATION FOR AMENDMENT TO LICENSE

Reference:

(3 ) DPC Letter, LAC-3929, Madgett to Director of Nuclear Reactor Regulation, dated May 18, 1976.

(2) NRC Letter, Reid to Madgett, dated October 29, 1976.

Gentlemen:

In answer t7 your request of Reference 2, enclosed for your infor-mation and further review is Supplement No. 2 to Dairyland Power Cooperative's reload application for Cycle 5 operation (Reference 1).

Included in this supplement are answers to questions No.

2, 7,

8 and 12 of the NRC's Enclosurc 2 that were telecopied to your offices December 30, 1976.

Additional information has been included in the answers to question !!o. 12 and the answer to question No. 3 has also been included in this Supplement.

The answers to questions No.

4, which involves cormiderabic computer analysis, and No, 11, 14, 18, 21 and 22 will be forLarded to you in Supplement No. 3 when they are completed about January 31, 1977.

Your early review and reply to this submittal would be appreciated.

If you have additional questions or comments regarding this submittal, please contact us as soon as practicable.

Very trulf yours, DAII<YLAND POWI:R COOPERATIVE i

.)

.lohn P.

Madgett, General Manager

.IPM: CWA:af ee-

.1 Peppler, Iw r.

Dit.,

N N '-l'! O lII 8110130361 810929

-PDR ADOCK 05000409

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SUPPLEMENT NO. 2 Additional Information to Application for Amendment to LACBWR Provisional Operating License No. DPR-45 Exxon Type III Fuel Reload Batch XN-1 Dairyland Power Cooperative 2615 East Avenue South La Crosse, Wisconsin 54601

~ December 29, 1976 J

l

SUPPLEMENT NO. 2 - ADDITIONAL INFORMATION

' UESTICil 2: The model ustd for the LOC 1-analyaio (XN-235, " Exxon Nuclear Q

..)

Evaluation Madct for BWR Loss of Coolant Accidente") applies to t

7 x 7 fuel. Shou hou this model was modified for application to tha 10 x 10 fuel in LACBWR.,

RE570tiSE:

The heatup model used in calculating the peak clad temperatures for the Eric La Crosse Reload Fuel is in conformance with the approved Ef'; fion-Jet Pump Bo.iling Water Reactor Fuel lie: top Model (fiJP-BWR-FHfi) wi th the exception that spray heat transfer coeff,1cients for the 10 x 10 reload fuel were used(2) rather than the approved " ray heat transfer coefficients for 7 x 7 fuel.(3)

The values of the spray heat transfer coefficients used in the Licensing Portfolio ( } appear in Table I along with the calculated peak cladd;r.g temperature obtained from the heatup calculations.

In order to determine the' sensitivity of peak clacding temperature to spray heat transfer coefficients, a set of 10 x 10 spray heat transfer coefficients were synthesized based upon the 7 x 7 values found 'n Reference 3.

The prbcedure to determine the synthesized set of velues I

is similar to that previousiy used (Telecopy to NRC dated 2/28/75) and is atbched for reference. The resulting values and corresponding peak cladding temperature using the synthesized set of coefficients are shown

[

in Table 1.

As is shown in Table I the peak cladding temperature using the synthesized heat transfer coefficients is 30*F higher than that oMrined in Reference 4 but is well belcw the Interim Acceptance Limit of 2300'F and represe nts no significant change in the conclusions s_.

presented in Reference 4.

Therefor.% it is considered unnecessary to recalculate the peak cladding temperatures for the DiC La Crc se Reload Fuel a

b:

lj.

.h

,3 L

TABLE I l )

~

i7 SPRAY HEAT TRANSFER COEFFICIENTS XN-75'qlpvision2)

SEtiSlii,rITY STUDY h Sprzy h Spray 2

2 Rod Group Btu /hr-ft PCT (*F)

Rod Group, Btu /hr-ft PCT (*F) 1 3.2 1

2.69 2

1.5 2

3.id 3

1.7 2178 3

1.45 2208 4

1.7 4

1.3) 5 1.5 5

1.34 6

1.25 i

C

v.

I d ' *'

DETERMINATION OF SPRAY IIEAT TRAMSFER COEFFICIENTS e

r The following treatment is presented to deter.a.ie spray heat transfer l

[ }

coefficients for the Exxon Nuclear 10 x 10 fuel assembly containing 96 fuel

['

rods derived from the approved Appendix K values for 7 x 7 BWR fuel assemblies containing 49 fuel rods.

1.

Definition of the Eftective Heat Transfer coefficient, h,ff The net rate of heat removal frr,ni a given rod in a fuel bundle can be represented by:

i

1. 9 rodto-other-surfaces (1) 9*9 rod-to-fluid The second ts:rm cr'nsists of thermal rwation frcm the rod to other rods and the channel. and vice versa, and is treated explicitly, both in the reduction of the test data and in the LOCA heatup analysis, with codes such as Exxon Nuclear's HUXY code. The first term is of interest here and may be written as the sum of a convection term and a radiation term:

= h A(T - T ) + care (T - T'h')

(2) 4 Orod-to-fluid r

f 7

viere:

temperature, R, of rod surface (r) and fluid (f)

T

=

2 true convection coefficient, Btu /hr-ft _g h:

=

Stefan-Boltriann constant a =

-8 2

0.1714 x 10 Stu/hr-f t -R

=

Pod surface area, ft A

=

radiation emittance factor from rod to fluid

=

t e the two tems of Equation (2) are combined in the models used for both the experimental data reduction and the t0CA analysis into one pseudo-convection torn:

_)

l

(

i

~

r.

a brew fluid

• heff(T -T)

(3)

A r

f

]

where h,ff is the " effective" convection heat transfer coefficient for spray cooling.

Equating the right hand sides of equations (2) and (3) and solving for h,ff:

h,f7 =h * "Te(T +T)(Tf+Tf)

(4) e r

f Equation (4) is the definition of the " convection" coefficient as used in BWR spray cooling analysis.

Its dual role should be noted. The coefficient includes not ontf amal convection but also thermal radiation from the rod to the fluid as well.

It is, therefore, extremely sensitive, to the volume fraction of water droplets suspended in the coolant in the imediate vicinity of the rod and to the temperature of the rod surface, in addition to vari-ables affr;*.ing normal convection, such as fluid velocity.

l 2.

Reduc t" n of 7 x 7 Soray Coefficients For the purpose of this analysis, the 49 fueled rods in a 7 -x 7 assembly j

are groJped as shown in Figure 1.

From equation (4), define 4 such that:

h,7f =h + n, (5) e 1

or:

2

= a (T # T ) (T

+T)

(6) r f

The values for h,7f recommended in flE00-10329, Appendix D, and accepted l

in 10'.M50, Appendix K, for jet-pump BWRs are listed in T@le I for each rod group.

The data in itED0-10329 indicate that the convective component 2

h can be estimated by a value of 0.7 Btu /hr-f t -F, which is conservatively lower than would be expecteo from natural convection alone.

l

n During a LOCA with a 2200*F peak' clad temperature,' the time averagnd

}

rod temperatures at the peak axial plane are strongly dependent upon position relative to the canister, increasing approximately 100*F.for each additional,

row from the canister.

It is assumed that the values of h,7f can be related to the effective values of T listed in Table I, yielding the effective values of r

t as listed.

e For the purpose of this analysis, assume the water droplets to be black body absorbers and,tne steam to be transparent. Therefore:

e r rd (7)

T

=t where e is the emissivity of the rod surface and F is the view factor from r

rd the rod to the droplets, defined as the f; action of the radiation leaving the rod which strikes the droplets. With a rod emissivity of 0.67, the values for t reduce to the view factors listed in Table I.

e During the spray cooling protion of the LOCA, the primary source of drop-lets in the assenbly is the sputtering of circplets from the various quench fronts on the rode and canister. Since quench velocity is inversely related to surface temperature, the quench fronts on passive surfaces (those not producing energy) would be lower than the quench fronts on the fuel rods.

In the 7 x 7 case, the only passive surface is the canister wall. Since the axial plane [

of most interest from a LOCA standpoint is at or below the midplane, the effective droplet density leading to h w uld be expected to be highest eff next to the canister, decreasing as distance fro:'t the canister increases. This

.rer.d is definitely evident in the view factor estimates listed in Table I.

?

,'J s

_.,.. _ ~, _,

.-._m,.

-- _.~.

PT 3.

Synthesis of 10 x 10 Spray Coefficients _

As in the case of the 7 x 7 assembly, the 10x 10 assembly rods.:gre grouped as showra in Figure 2.

Replacing a 7 x 7 assembly with an ENC 10 x 10 asserNy in a given LOCA spray cooling situation would have a negligible effect on the mechanisms of spray cooling embodied in equation (4).

The value of 0.7 Btu /hr-2 f t -F assumed in Section 2 should also apply to the 10 x 10 assembly.

The can quench velocity will be roughly the same for both cases, and would be expected to produce droplets at the same rate and size distribution in both cases. The fraction of free area for crossflow in the 7 x 7 is 0.23; for the 10 x 10 it is 0.29.

Thus, the resistance to crossflow would be about the same in both cases.

If the canister were the only passive surface in the assembly, one would expect about the same effective droplet distribution within the assembly for oath the 7 x 7 and 10 x 10.

For the following development, assume the droplet densities for each rod group in the 10 x 10 (Figure 2) to be the same as those in the 7 x 7 (Figure 1).

This allows tne view factors, Frd, calculated for the 7 x 7 rod groups to be used as a basis for the estimation of 10 x 10 view factors.

Consider a rod of radius r radiating into the surrounding subchannels. Radi-g ant energy leaves the rod sarface at some intensity !g and is absorbed as it passes through the droplet-steam mixture, with the amount of energy being porportional to the intensity of the radiation and the absorbtlon coefficient of the medium, v.

Then if we look at the control volume, dr.

j-h = - pl - I/ r (8) 1 s

N

~

7 i

n or

~

i.

~)

l!

~

Ir

-p(r-r)

=e g

lr

. (g) gg Then equation (9) represents the intensity I of the radiant energy at ;cce

.adius r.

To find the total energy passing through a circle of radius r, one must integrate around the rod. That is 2N E=

lrdo g

(10)

Thus the total energy being radicted by the rod is E,.od

• I "ed0

• I 2nr o

o o

g (33)

The total energy passing through the fluid is then 1

i

=[g U

E lnet(r + a)do = 2n(r

+ a)l (12) ggt g

g ngt Where a is the ef fective channel annelar width.

By definition:

I E

E

!% k Ch r

=

(13) rd t rod Substituting e;untions (11) and (12) into (13) and rearranging:

lHel(""

8

~

'r I'$

id" Ir OO (14) l E 6

.e.

R Equation (11) eni (9) cin he solcod for D

a:

r l-1

)

- I ll h i o,,'

( 'l ga il

i

}

which defines the absorbtion. coefficient for a given droplet density.

)

Thus, for a given droplet density, the view factors are related to q

effective channel annular width by a,Ja

\\

(1 - Fg)2 = (1 - Frd)1 (16)'

Since the subchannel geometry in the 10 x 10 assembly is similar to that for the 7 x 7 fuel assembly, agai, is calculoied as the ratio of effective channel annular wndths and is found to be equal to 0.6507

Thus,

.6507 (1 - F I

=0-Frd) 10 x 10 (17) rd 7x7 using this relationship, the 7 x 7 view factors were reduced to the values listed in Table Il for the 10 x 10 assembly. These values, along With an emissivity of 0.67, yielded the tabulatea values of t f r the e

10 x 10 assembly.

Since the EriC 10 x 10 design employs four non-fuel rods in the center of the assembly, the effective rod temperatures as listed in Table II are more appropriate than the temperatures of Table I.

These temperatures were used to yield the values of ?t and h for each rod group in the e

gf EriC 10 x 10 assembly and are representative of the-averaged te.nperatures during a heatup for the 10 x 10 assembly.

The Table !! spray coefficients derived assuming droplet densities identical to those of the corresponding rod groups in the 7 x 7 assemblies are lower tnan the 7 x 7 spray coefficients.

In the actual Q

case, higher droplet densities would t;e expected in the ENC 10 x 16 assembly during spray cooling due to tne droplets sputtering from the quench fronts on the four passise rods 'n the certer cf x.e-!1v.

Even without the passive rods, the droplet den'sity h,>uld La expected

, q}

to be somewhat greater than the 7 'x 7 case in tae area adjacent to the canister, since the droplet production rate would be the same, but the,

subchannel area is' smaller. The net effect of this increased droplet t

density would be to increase the spray coefficients ter rod groups 1 and 2 to their 7 x 7 level, and to increase the coefficienti for groups 4 and 5 well.above their 7 x 7 level, f

O I

l i

f 4-t s.

}

e V) t

f-l-

TABLE I REDUCTIO li 0F 7 X 7 SPRAY COEFFICIErlTS Rod Cec ;

1 2

3 4

5 7x7 hef f ( App. K),

• 3.0 3.5 1.5 1.5 1.5 h,*

0.7 0.7 0.7 0./

0.7 c

tr,

• 23 2.8 U.8 03 0.6 g

Effective T,

F 1400 1500 1603 1700 1800 r

4,*

17.0' 19.4 22.0 24.8 27.9 t

0.136 0.147 0.036 0.032 0.029 e

F 0.202 0.216 0. 0 5 ',

0. 0 f,8

0. 0 f. 3 rd

• Blu/hr r 2.ro

.,)

W TABLE II

,)

1 SYNTHESIS OF 10 x 10 SPRAY COEFFICIENTS Rod Gr;up 1

2 3

4 5

6 10x10 with 4 passive rods h'*

c 0.7 0.7 0.7 0.7 0.7 0.7 Assuming droplet densities equivalent to 7 x 7:

F

.137

.146

.036

.032

,028

.025 rd t

• 092

• 09S

• 024

• 02l

• 01 9 *017 e

Effective T

• F 1550 1680 1870 1910 1930 1890 7

0,*

21.58 25.26 31.39 32.80 33.53 32.09 Ot 1.99 2.48

.75

.69

.64

.55 e,

h 2.69 3.18 1.45 1.39 1.34 1.25 g7f 2

• Btu /hr-ft

• F

.)

1

P'1 t

)

t OD I

ROUP I ROD GR UP 2 l

i

_ __-___-__r_-_

j I

l RO GRO F 3 I

i.

i r _ _

i ROD Gn UP ll I

I l

r-7 I

I i

1 R0D I

l GR UP I

g I

L_-I I

i i

.m l

.e m l.. -

i i 1 i

1 1

1 l

l I

i

(

(

(

l l

\\

t t

I l

I 1

i i

I 3.

3 1

%Y FIGURE 1 Sl' RAY COEFF1C1Er.'T POD GROUPlilG F0lt 7 X 7 ASSEI4BLY g =

N

1:

}.-

ROD GROUP 1 Cio o 0"O o o o olo o+j o se o. __. _._ __._.._._.

__l__ _. _.

~

oooojo o!o[ao seoojoO~MHUQ olololoC~Dioljolojo l

oiol o!ojoloLOojolojolo 0

olol0Q_o_O ojeloo oloLO_O_O_O_o ojolo oC_R_O_O_O_O_O_OD Q00000000!O FIGURE 2 SPRAY COEFFICIEfiT R0D GROUP!r4G TOR 10 x 10 ASSEf43LY

)

\\

L.

1

e

~

' REFERENCES l0R RESPONSE TO QUESTION # 2 A Generalized Multirod Heatus Code with 10CFR50 Appendix K Heatup "HUXY:

1.

Option - User's Manual", Xft-CC-33 (A), Revision 1. November 1975..

" Technical Evaluation Adequacy of Lacrosse Boiling Water Reactor Emergercy i

2.

I Core Cooling Syster.". SS-942 May 31,1972.

I 3..

10CFR50, Appendix K

" Licensing Portfolio for Dairyland Power Cooperative Exxon Nuclear' Reload 4.

Batch I (Type III Assemblies)", Xft-75-20 Revision 2. February 6,1976, l

e e

e k

M f

5

~

l 1

5 QUESTI0tt 3:

You have assumed no rod ballocning in performing the rod heatup

)

calculations, and have referenced La Crosse documents 55-942 and 4

55-1073 to substantiate your assumption, C*te the specific bases in these references that demonstrate the validity of your assumption, i

PESPCt'SE:

Fod ballooninq has been evaluat.ed in previous sutnittals (References 4, 5, 6) where it was concluded that hallooning in the LACBt:P f uel would l'e minir'al during a LOCA and fuel rod ecoling would not be substantially affected.

Recently, the results of a Post Irradiatier Evaluation (PIE) (Re f. 7) performed 1.

ene n i r]ectric Cent any for Drc, speci ficali, burst tests and !iiqh Tenr.'rature Transient (UTT) tests, support thir conclusion.

the Circumferential Uniforn Elongation In these tests, also a neasure of the change in fuel rod (CCF), which :n claddino diancter, following rupture was determined as well as other cladding mechanical proporties under various conditions of internal pressure and cladding tenperature.

CUE values of approximately 1-21, were obtained from 0

irradiated ~1 adding at torporatures from 70 F to 2300 F l

indicating that a diameter increase of less than 2% would be expected for irradiated cladding.

CUE values for un-irradiated specimens were 3 141 in the mnge of 700 F to 230rpy 0

and about 22; for unirradiated material at room tempe -

aturt These values of ballooning and resulting reduction in flow area are sufficiently anall such that rod cooling wnuld nnt 1,o siqnificant!" affec*<:d.

e

6 In addition, an average gap conductance value of

)

440 BT wan used in the computation of fuel and 2

hr-ft 03 cladding temperaturen as reported in SS-1085 and was conservatively applied over the full ranqo of the temper-ature transient.

necause of the conservatinm of the manner in whic'n the gap conductance value in applied and the minimal cffccts on rod cooling due to the small diametral e>:pansion of the r,tainless-steel cladding during a LOCA, the effecta due to minor hallooning are considetec' to be negligible.

r l

l l

l l

l 1

,.... ~.- _

s QUESTloti 7: Provida the equation used to represent the natal-vater reaction of tiia

.}

stainleca stcci, If it is Equation 91b of XN-73-34, Revision 2 (XN-CC-33), chcv hou it was developed.

Give cpecific pages :n tha referenca mentioned (The Acrospace Structural Metals Handbook) that ucre used in e

developing Eq'tation Bib, RESP 0tiSE: The reference for the expression for tha metal-water reaction of the stainless steel cladding (Equation 81b of Xfi-CC-33) is not the Aero-l, space Structual Metals Handbook, but is based upon experimental data as referenced in Section 7 of 55-942.

The amount of oxygen uptake per unit area is given in the above reference as:

2 12 2.4 x 10 t exp (-84,300/ U' W

=

where, mg/cm of oxygen uptake per unit area of the clad surface W

=

time in seconds t

=

gas constant,1.987 cal / mole = K R

=

temperature. *K T

=

This expressicr was ccaneted into a reaction rate of cladding material reacted in units of in/ sec and the terrperature units changed to degrees Rankine for use in HUXY (Xfi-CC-33). inis conversion was accomplished by taking the time derivative of the above equation with the following:

3 (1) a clad density of 8 gm/cm for the stainless cladding, and (2) the r

weight ratio of stainless steel oxygen reacted as 2.62 (Appendix D, 55-942). performing the indicated operations and adjusting units yicids:

_.)

i h

l

\\

O I2 de (2.62)2 2.4 x 10

- 84,300 (1.8) 2 N 2e (2540)(8)

T (1.987) 19945

- 76366 a

T where. T is the temperature at the metal-oxide interface (*R) e 15 the oxide thickness (inches) t is time (seconds)

The above expression is Equation 81b of Xti-CC-33 and was used in the La Crosse analysis to determine the metal-udter reaction durin9 the LOCA.

{

e r

ll hl.

l<e qutSTION S: Qacify the input valua for tha oxide thickneca at the initiation of

)

a postulated LOCA on the insida and outaida cladding sta'facco. Justify tha use of theca input valuca.

l RESP 0tiSE: The initial oxide thickness on the inside and outside surfaces.of the cladding was input as zero in performing the heatup calculations for la Crosse. This has the effect of maxit.:+ %) both the amount of cladding reacted as'well as any heat of reaction produced by the metal-Water reaction and is therefore the most conservative value to use in the analysis.

f I

s s

s

- - ~ ~.. - - -.. - _ _ _. _ _. _ _ _ _.

_