ML20198L828

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Rev 4 to Calculation BRW-97-0798-M, Allowable Leak Rate Calculation for SG Interim Plugging Criteria
ML20198L828
Person / Time
Site: Braidwood  Constellation icon.png
Issue date: 12/10/1997
From: Launi C
COMMONWEALTH EDISON CO.
To:
Shared Package
ML20198L802 List:
References
BRW-97-0798-M, BRW-97-0798-M-R04, BRW-97-798-M, BRW-97-798-M-R4, NUDOCS 9801160132
Download: ML20198L828 (27)
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Braidwood Calculation No. BRW-97-0798-M Allowable Leak Rate Calculation for Steam Generator Interim Plugging Criteria Revision 4 12/10/97 1:

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9001160132 980114 PDR ADOCK 05000456 P pm

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4 PREPARATION, REVIEW AND APPROVAL OF CALCULATIONS CALCULATION TITL.E PAGE Calculation No: BRW-97-0798-M DESCRIPTION CODE: ROI DISCIPLINE CODE: M BRAIDWOOD STATION UNITS 1&2 SYSTEM CODE: RC.MS DLE: Allowable Leak Rate Calculation for Steam Generator Interim Plunninn Criteria

__X_ Safety Related Austmented Quality Non-Safety Related REFERENCE NUMBERS Type Number Type Number COMPONENT EPN: DOCUMENT NUMBERS:

EPN- Compt Type Doc Type / Subtype Document Number I

REMARKS:

REV. REVISING APPROVED DATE ORGANIZATION PRINT / SIGN 0 S&L C. M. ' auni/(See original for signature) 8/29/97 i S&L C. M. Launi/(See original for signature) 9/3/97 2 S&L C. M. Launi/(See origmal for signature) 9/22/97 3 S&L C. M. Launi/(See original for signature) 9/30/97 4 54L l'NfL N M. /Janl (2h/A 7 p

4

.m.

COMMONWEALTH EDISON COMPANY CALCULATION REVISION PAGE .,

CALCULATION NO. BRW-97-0798-M PAGE NO.: 2 REVISION SUMMARIES

~

REV: 0 REVISION SUMhiARY:

Originalissue, pages 1-23 .

Electronic Calculation Data Files:

(Program Name, Vmiert File name e-usuesdatehourt: nun)

None Prepared by: W. J. Johnson /(See cricinal for signature) 8/29/97 Print / Sign Date Reviewed by: R G Chow /(See oricinal for signature) 8/29/97 Print /Sinn Date Type of Review

[ X ] Detailed [ ] Alternate [ ] Test DO ANY ASSUMITIlONS IN THIS CAlfUIAllON REQUIRE LATERVERIHCA110N [ ] YES [X]NO Tracked by:

REV:1 t REVISION

SUMMARY

Corrected typographical error on page 24.

Electronic Calculation Data Files:

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None Prepared by: W. J. Johnson /(See original for signature) 9/3/97 Print / Sign Date Reviewed by: R. G. Chow /(See original for siunature) 9/3/97 Print /Siun Date Type of Review

[ X] Detailed [ ] Alternate [ ] Test DO ANY ASSUMI'IlONS IN THIS CAlfULA110N REQUIRE LATERVERIFICATION [ ] YES -[ X] NO Tracked by:

v e

4th

COMMONWEALTII EDISON COMPANY CALCULATION REVISION PAGE CALCULATION NO. BRW-97-0798-M PAGE NO.: 2.1 REVISION SUMMARIES REV: 2 REVISION

SUMMARY

Corrected secondary side activities based on new information from Westinghouse. Also corrected typographical errors on page 12 and 23.

Electronic Calculation Data Files:

(Mgram Name. Version, Fde name exvsus/datshour/: mm)

None Prepared by: W. J. Johnson /(See oriuinal for signature) 9/22/97 Print / Sign Date Reviewed by: R. G. Chow /(See oriuinal for siunature) 9/22/97 Print / Sign Date Type of Review

[ X 1 Detailed [ ] Alternate [ ] Test DO ANY ASSUMPIlONS IN DilS CAILUATION REQUIREIA7BlVERIFICADON [ ] YES [X]NO Tracked by:

REV: 3 REVISION

SUMMARY

Added secondary side releases to LPZ 0-2 hr dose. Clarified references, design inputs, and text.

This revision completely supersedes all previous revisions.

Electronic Calculation Data Files:

(Program Name, version, f ue name extiue/datshour/: mm)

None Prepared by: W. J. Johnson /(See original for signature) 9/30/97 Print / Sign Date Reviewed by: R. G. Chow /(See original for signature) 9/30/97 Print /Sinn Date Type of Review

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. . . . . . . . . - . . - ~ . _w

COMMONWEALTH EDISON COMPA TY CALCULATION REVISION PAGE ,

CALCULATION NO. BRW-97-0798-M PAL E NO.: 2.2 REVISION SUMMARIES

~

t REV: 4 REVISION

SUMMARY

Revised dose resulting from new end-of-cycle 7 leak rate. Pages affected: 2.2,3,6,23,24.

Electronic Calculation Data Files:

(Program Name. Version. File name ext stadate.tourt: mm)

None Prepared by: W. J. Johnson / ,/////

~ ~

) %/> 0/4 7 ,

Print /Si[n/ " Date The rmewer's signaties ind cates comphance with GES 320.10 and the venfication of the followmg nummum items: correctness of math for hand calculatsons, appropnateness ofinput data, appropnateness of, ass ipuons. and appropnateness of the calculation method.

Reviewed by: R. G Chow / /C /2 ' 7 prindSign Date Type of Review

[ X ] Detailed [] Alternate [ ] Test DO ANY ASSUMPDONS IN THIS CAlfULATION REQUIRE LATER VDUFICA110N [ ] YES [X] NO Tracked by:

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REVISION

SUMMARY

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Prepared by:

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4 mm

9 1

COMMONWEALTH EDISON COMPANY CALCULATION TABLE OF CONTENTS

-CALCULATION NO. BRW-97-0798-M REV.NO.4 PAGE NO. 3 SECTION PAGE NO. SUB-PAGE NO.

TlTLE PAGE 1 REVISION

SUMMARY

2 2.1,2.2 l TABLE OF CONTENTS 3 PURPOSE / OBJECTIVE 4 METHODOLOGY AND ACCEPTANCE CRITERIA 4 ASSUMPTIONS 5 DESIGN INPUT 5 REFERENCES 6 CALCULATIONS 7

SUMMARY

AND CONCLUSIONS 24 ATTACHMENTS N/A I

l

l COMMONWEALTH EDISON COMPANY l CALCULATION NO. BRW-97-0798-M PROJECT NO. PAGE NO. 4 l PURPOSE AND OBJECTIVE:

The purpose of this calculation k to generate the maximum allowable primary to secondary steam generator tube leak rate during a postulated main steam line break using 24% plugging criteria design data. The evaluation was performed for both a pre-accident and eccident initiated lodine spike. The release of iodine and the resulting thyroid dose at the Exclusion Area Boundary and Low Population Zone were considered in the leak rate dotermination.' Whole body dose due to noble gas immersion is less limiting tilan thyroid dose as documented in UFSAR Table 15.0-11. Given the large margin to the 25 rem whole body dose limit, whole body dose was not re-evaluated.

T. Is calculation also determines the resulting thyroid Cose at the Exclusion Area Boundary and Low Population Zone for the actual predicted end-of-cycle 7 steam generator tube leakage during a postulated Main Steam Line Break METHODOLOGY AND ACCEPTANCE CRITERIA:

The Main Steam Line Break (MSLB) accident is evaluated because the event causes a sustained large pressure difference across the steam generator tubes providing a motive force for reactor coolant system (RCS) release.

The dose attributed to a 1 gpm leak rate from the reactor coolant system was calculated. This value was then used to determine the allowable leak rate without exceeding the Standard Review Plan dose criteria.

The activity released to the environment due to a MSLB is analyzed in two distinct releases-

1. The release of the iodine activity that has been established in the secondary coolant prior to the accident, and
2. The release of the primary coolant lodine activity due to tube leakage.

The methodology used for calculating the Radiological Consequences of a MSLB with primary to secondary leakage is consistent with the Standard Review Plan (NUREG 0800),15.1.5 Appendix A.

TID-14844 dose conversion factors were used to determine dose equivalent iodine co'1centrations for the RCS, which is the Technical Specification definition of dose equivalent todine. The TID values are based on ICRP 2,

" Permissible Dose for Intemal Radiation,1959.*

The off site dose assessment uses ICRP 30,

  • Limits for intakes of Radiont.clides by Workers,1979* dose conversion factors. ICRP 30 is also the basis for Federal GuW.nce Report No.11," Limiting Values of Radionuclide intake and Air Concentration and Dose Conversion Factors for Inhalation, Submersion, and ingestion," dated 1988.

The dose Acceptance Criteria are based on the guidance of Standard Review Plan (NUREG-0800) Section 15.1.5, Appendix A. For a MSLB with a postulated pre-accident lodine spike, the calculated doses should not exceed the guideline values of 10CFR Part 100 Section 11. The numerical values used for these doses are 25 rem to the whole body and 300 rem to the thyroid from lodine exposure for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> following the accident. For a MSLB with an accident initiated lodine spike, the calculated doses should not exceed a small fraction of the 10 CFR 100 guideline values, i.e. 2.5 rem and 30 rem respectively for the whole body and thyroid doses.

I REVISION NO.: 4 l 1

~6 COMMONWEALTH EDISON COMPANY r l CALCULATION NO. BRW-97-0798-M PROJECT NO. PAGE NO. 5 l ASSUMPTIONS: -

.1) The effect of b0ron on the RCS density is assumed to be negligible since the boron mass is less than 1%

of the total RCS mass at the beginning of core life.

DESIGN INPUTS:

1. The total volume of the RCS is.12,062 ft3 . (Ref.1)
2. The full power RCS temperature and pressure are 586.2 *F and 2250 psia. (Ref.1 and 2) 3 3.' The RCS specific volume at full power is 0.02258 ft /lbm. (Ref. 3)
4. (Deleted)
5. Letdown Purification System temperature and pressure are 130 *F and 2300 psig. (Ref.1).
6. Letdown Purification System specific volume is 0.01613 ft'llbm. (Ref. 3)
7. Breathing rates are taken from UFSAR Table 15A 1. (Ref. 6)
8. Atmospheric Dilution Factors, X/Q, are the fifth percentile values taken from UFSAR Table 15.0-14.

(Ref. 7)

9. RCS lodine concentrations are based on UFSAR Table 11.1-2. (Ref. 8)
10. The initial steam release frum the defective and intact steam generators are taken from UFSAR Table 15.1-3 (Ref. 9)
11. The secondary side faulted steam generator has a partition coefficient of 1.0 and the intact steam generators have partition coefficient of 0.1. (Reference 15)
12. The half life for 1-131 is 8.04 days,1132 is 2.30 hrs.1133 is 20.8 hrs,1 134 is 52.6 min, and 1-135 is 6.61 hrs (4 = 0.693/ half life).-(Ref. 21)
13. The initial primary coolant activity for the pre-accident spike is 60 Cl/g DE l-131 and 1 C1/g for the accident initiated spike. (Ref.12 and 14)
14. The initial secondary coolant activity is 0.1 Cl/g DE l 131. (Ref.12 and 14)
15. The duration of the spike is 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. (Ref. 24)
16. No fuel failure attributable to the accident since Dh8 design basis is met. (Ref.12 and 25)
17. lodine partition coefficients for all SGs are 1.0 for pr' mary-to-secondary leakage. (Ref.15)
18. Normal letdown purification flow is 75 gpm. (Ref 1)
19. (Deleted) l REVISION NO.: 4 j u.

.i y

COMMONWEALTH EDISON COMPANY PAGE NO. 6 l

@ALCULATION NO. BRW-97-0798-M PROJECT NO.

20. (Deleted)
21. Demineralizer Decon Factor, DF for lodine is 10. (Ref 1)
22. The lodine release rate spike factor is 500. (Ref 12)
23. Allowable primary to secondary leak rate is 150 gallons per day (0.1 gpm) per steam generator. (Ref.14)
24. Dose conversion f actors are based on ICRP 30 values using 'he significant digits from Federal Guidance Report No.11. (Ref.17 and 20; 9 25. Projected eno-of-cycle 7 leak rate is 122 gpm based on room temperaturt'and pressure. (Ref. 5)

REFERENCES:

1) B/B UFSAR Table 11.1-1, Revision 0, as amended in Reference .22
2) B/B UFSAR Table 5.1-1, Revision 0
3) ASME Steam Table, Fifth Edition
4) (Deleted)
5) BRW DIT 97-278, inputs into Offsite Dose Culcula'.

Umit, Rev. 2 .o Support Unit 1 Reduced RCS DE l-131 Activi

6) B/B UFSAR Table 15A 1, Revision 0
7) B/B UFSAR Table 15.0-14, Revision 0
8) B/B UFSAR Table 11.12, Revision 0
9) B/B UFSAR Table 15.13, Revision 6
10) Introductory Nuclear Physics by Kenneth S. Krane,1988
11) (Deleted)
12) Standard Review Plan (NUREG 800),15.1.5 Appendix A .
13) (Deleted)
14) Technical Specifications 3.4.8 (Amendment 69),3.7.1.4 (Original), 3.4.6 2 (Amendment 57)
15) WCAP 14048, *B aidwood 1 Technical Support for Cycle 5 Steam Generator Interim Plugging Criteria,"

dated May,1994.

l REVISION NO.: 4- l l e.

e I

i COMMONWEALTH EDISON COMPANY l CALCULATION NO. BRW-97-0798 M PROJECT NO. PAGE NO. 7 l

16) ICRP Publication 2, Report of Committee 11 on Permissible Dose for intemal Radiation,1959
17) ICRP Publication 30, Limits for intakes of Radionucildes by Workers,1979
18) J. P. Adams and C. L. Atwood,"The lodine Spike Release Rate During a Steam Generator Tube Rupture,' Nuclear Technoloov. Vol. 94, pp 361371 June,1991 and EGG NERD-8648 Technical Report
  • Probability of the lodine Spike Release during an SGTR,* September,1989
19) Westinghouse Letter CAE 97-171, dated July 21,1997, pertaining to the Reactor Coolant Water Density Used in Determining Byron and Braidwood Altemate Tube Plugging Limit.
20) Federal Guidance Report No.11," Limiting Values of Radionuclide intake and Air Concentration and '

Dose Conversion Factors For Inhalation, Submersion, and Ingestion,1988

21) NUREG/CR 1413, "A Radionuclide Decay Data Base -Index and Summary Table," 1980
22) ' Primary Coolant source Terms," Westinghouse letter CAE-97-185, CCE 97-225, dated September 19, 1997
23) TID-14844, " Calculation of Distance Factors for Power and Test Reactor Sites," March 23,1962
24) B/B UFSAR Section 15.1.5.3, Revision 6
25) B/B UFSAR Section 15.1.5.1, Revision 4 VARIABLE AND CONSTANT DEFINITIONS:

M RCS mass [g]

M., Steam Generator steam release mass [lb]

V RCS volume [ft']

v RCS specific volume [ft'/lbm]

) RCS leak rate constant [sec"]

k,. Fuel Release constant [Ci/sec]

4 isotope Decay Constant [sec"]

d 4.o Letdown Purification Removal Constant [see ]

d 4 Totallodine Removal Rate [sec ]

t Time [sec]

A, RCS iodine activity [Ci]

C, todine Concentration [Cl/g or Cl/g]

C. Initial lodine Concentration [Cl/g or Cl/g]

F. Letdown Purtfication Flow [g/sec] -

R. Activity Released of nuclide,I[Cl]

D Thyroid Inhalation Dose [ rem]

B Breathing Rate [m*/sec]

X/Q Atmospheric Dilution Factor [sec/m ]

W, DCF-Weighted Activity [ rem]

DE l 131 Dose Equivalent 1131 I REVISION NO.: 4 l l l

O I e COMMONWEALTH EDISON COMPANY l CALCULATION NO. BRW 97-0798-M PROJECT NO. PAGE NO. 8 l DETINE UNITS:

Cl = 1 Curie Ci= 1E 6 Cl 1 lbm = 454 g 1 ft' = 7.48 gal 1 min = 60 see 1 Sv/Bq = 3.7E12 rem /Cl /

1. - CALCULATION OF DOSE DUE TO STEADY STATE ACTIVITY IN SECONDARY SIDE The first dose component to be calculated will be the dose from the secondary side. The secondary side _

activity is conservatively taken as the Technical Specification limit of 0.1 Cl/g (Design input 14). This value is the same for both the pre-accident and accident initiated events. The steam release for the faulted steam generator (SG) is 96,000 lbs (Design input 10) wnich is the entire initial SG water mass.

The faulted SG is assumed to steam dry in 10-15 minutes so all of the lodine is available for release.

The combined 0-2 hr steam release for the th" m.Mct steam generators is 406,716 lbs (Design input 10). The combined 2-8 hr:, team release for y u 'ntact SGs is 939,604 lbs (Design input 10). For the three intact SGs a partition coefficient on - sed (Design input 11),

a, The iodine concentrations are obtained from UCSAR Table 15.0-9 as updated in Reference 22 and are converted to Cl/lb. since the steam release is defined in Ibs.

C = C, x 454 x 1E - 6 Equation 1.n

. lb , ,g, ,1b. , Cl.

TABLE 1.a Nuclide - lodine Concentration, C . .. lodine Concentration, Cu (UFSAR Table 15.0 9,'Ref 22): i(Equation.1.a)-

"[ Cl/0] -[Cl/lb]:

1131 0.0645 2.93E 5 l132 0.0723 3.28E 5 l133 0.1032 4.69E-5 l134 0.0155 7.042-6 l-135 0.0567 2.57E-5 l REVISION NO.: 4 l

)

_.L.-._--_u____-.-- ___ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ,

1 COMMONWEALTH EDISON COMPANY l CALCULATION NO. BRW 97-0798 M PROJECT NO. PAGE NO. 9 l

h. The iodine concentration for each nuclide, C, from Table 1.a. is multiplied by the mass of steam released (96,000 lbs for the faulted SG and 406,716 lbs for the three intact SGs) and then multiplied by the partition coefficient (1.0 for the faulted SG and 0.1 for the intact SGs) to obtain the curies released, R., for 0-2 hours.

R'"[Ci)= C, x M7(Ib]x1.0 Equation 1.b.1

_ lb .

RF(Ci)= C, x M7(Ib]x 0.1 Equation 1.b.2

_ lb _

TABLE 1.b

= Nuclide Activity Released from .

.- Activity Released from -

Faulted SG, R[*". . Intact SGs (0-2 hrs), R/",

(Equation 1.b.1) [Ci]- (Equation 1.b.2) [Cf]

t131 2.81E0 1.19E0 1132 3.15E0 1.33E0 1-1L 4.50E0 1.91E0 1-134 6.76E 1 2.86E-1 1-135 2.47E0 1.05E0

c. The activity released, R. determined above, is muttlplied by the ICRP 30 Dose Conversion Factor, DCF,. (Design inpal 24) for each lodine isotope and then summed separately for the faulted SG and intact SGs. The DCF-weighted activity released is:

W["(rem]= R["[Ci)x DCF, Equation 1.c.1

. Ci .

W"(rem) i = R,"(Ci]x DCF, Equation 1.c.2

. Ci .

I REVISION NO.: 4 l

_ _ _ _ _ _ - - _ _ . _ _ , _ , _ , . _ . - _ _ _ _ _ _ _ - _ _ -_ _ _ _ . _ , _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ 1 ______.__

I COMMONWEALTH EDISON COMPANY l CALCULATION NO. BRW-97-0798 M PROJECT NO. PAGE NO.10 l TABLE 1.c Nuclide ICRP-30 Dose . Weighted Activity; Weighted Activityc Conversion Factor, - from Faulted SG,- from Intact SGs,-:

DCFi, (Design input W'"", W'"", (9-2 hrs) :.

24) [ rem /Ci] (Equation 1.c.1) [ rem] (Equation 1.c 2)Irem]:

1131 1.08E6 3.03E6 1.29E6 l-132 6.4423 2.03E4 8.57E3 1-133 1.80E5 8.10E5 3.44E5 l134 1.07E3 7.23E2 3.06E2 I-135 3.13E4 7.73E4 3.29E4 TotalI(RixDCFi) 3.94E6 1.68E6 The 0-2 hour weighted activity released from the faulted and the three intact SGs is 5.62E6 rem (3.94d6 + 1.68E6 rem). This total weighted activity can also be defined as I,(R,xDCF).

The DE l-131 activity released from the faulted and intact seam generators is the total weighted activity from Table 1.c divided by the 1131 dose conversion factor. Numerically this is 5.20 Cl DE l-131 (5.62E6 rem /1.08E8 rem /Cl)

d. The off-site thyroid inhalation dose at the exclusion area boundary, Das, is calculated in accordance with UFSAR equation 15A-2. The LPZ doses for both the pre-accident and accident initiated lodine spike cases include the activity released from the secondary side and are calculated in steps 2.f and 3.f, respectively. The breathing rate is based on the 0 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> time period.

Exclusion Area Boundary Dose (0-2 hours) for Secondary Side Release e m Das(rem]= 5-- xBx (R, x DCE) Equation 1.d.1

( Q s uo x3.47E-4 *-

. x 5.62E6(rem]

= 7.7E-4 L $m . ,sec

= 1.50(rem]

l REVISION NO.: 4 l

COMMONWEALTH EDISON COMPANY ,-

, l CALCULATION NO. BRW 97-0798 M PROJECT NO. PAGE NO.11 l

2. CALCULATION OF DOSE DUE TO PRIMARY-TO-FCONDARY LEAKAGE DURING PRE-ACCIDENT INITIATED SPIKE in accordance with Reference 12, the pre-accident case occurs when the reactor is operating at the maximum value permitted by the Technical Specifications prior to the postulated MSLB. The radioactive isotopes are assumed to be evcnly distributed throughout the RCS. The lodine activity changes over time due to radioactive decay and the rate at which activity leaves the RCS due to primary-to-secondary tube leakage.
a. The RCS mass inventory, M, will be calculated given the hot full power volume and specific volume.

8 RCS Volume: V=12062 ft (Design input 1)

RCS specific volume v=0.02258 ft'/lbm (Design input 3) 9 (g) = x 454 Equation 2.a ft 3 .lbm, v

12062 ft 3 0

, x 454 3

ft -lbm-0.02258 g .

= 2.42E8 (g)

b. The RCS activity neuds to be calculated for 60 Cl/g DE l-131. UFSAR Table 11.1-2 is used to obtain RCS activity, which is based on 1% fuel clad defects per UFSAR Table 11.1-1. The total initial RCS activity is calculated by multiplying the initial concentration by the RCS mass. The initial DE l-131 activity is then determined by multiplying each isotope's activity by its dose conversion factor, summing the values for each nuclide and dividing the sum by the 1-131 dose conversion factor to normalize the activity to 1-131. This DE l-131 activity is the contribution due to 1% fuel clad defects. To determine the activity at 1 pCl/g DE l-131, the fraction of each isotopes contribution to the DE l-131 is calculated and then multiplied by the RCS mass to obtain the corrected total activity in the RCS at 1 Cl/g DE l-131. To obtain the total activity at 60 pCl/g

' DE l-131, each isotope activity is multiplied by 60.

' [ REVISION NO.: 4 l 4

I I

l l

COMMONWEALTH EDISON COMPANY-l cal.CULATION NO. BRW 97-0798-M PROJECT NO. PAGE NO.12 l A,[Ci]= C,, xM(g) Equation 2.b.1

.B.

Wi [ rem]= A [Ci]x DCF, '7

. Ci .

Equation 2.b.2

[W' (rem]

i I' *

= = 939.2 [Ci]

Dell 31[Ci]= -

DCFmi

_ @Ci 1.48Ef['*?

Ci .

Ci A,(Ci Nuclide Concentration at 1 DE I-131 =

g DE Il31[Ci) Equation 2.b.3 1 Ci RCS Activity at 1 x Equation 2.b.4 g (Ci]= Equation 2.b.3 x _g, M(g]x1_lE6 pCi _

RCS Activity at 60 Equation 2.b.5 8 (Ci]= Equation 2.b.4(Ci]x 60 TABLE 2.b Nuclide .RCS RCS ICRP-2 '. Weighted; . Nuclide RCS Total RCS Total.

Concent., .' Activity, . Dose. LActivity,- ~ Concent L Activity at Activity at:

C. - Ac Conversion jWi iat 1 pCl/g 1 pCl/gl 60 Cilgi

. (UFSAR (Eq. Factor DCFi - (Eq. 2.b.2)' (Eq. 2.b.3) (Eq. 2.b.4) ' (Eq.12.h.5 L Table i- 2.b.1) [ rem /Ci] '. 1[ rem]!.- ',[ Cilg]i ~ '

[Cf] ' E [Cl])j L 11.1-2) [Ci] - (Ref. 23) ,

' [Cilg]

l-131 2.5E4 605 1.48E6 8.95E8 0.645 156.1 9.36E3 1132 2.8E-6 678 5.35E4 3.63E7 0.722 174.8 1.05E4 l-133 - 4.0E 6 968 4.00E5 3.87EB 1.032 249.7 1.50E4 1134 6.0E-7 145 2.50E4 3.63E6 0.155 37.5 225E3 1-135 2.2E-6 532 1.24E5 6.60E7 0.566 137.3 8.23E3

IW i . 1.39E9 l REVISION NO.: 4 l

COMMONWEALTH EDISON CO?APANY-I CALCULATION NO. BRW.97-0798-M PROJECT NO. PAGE NO.13 l

c. The two removal mechanisms for this accident are due to decay and loak rate to the secondary side of 1 gpm. The time dependent activity after two hours with the removal constants can be csiculated using the basic decay equation methodology (Reference 10).

dA(t)

= - A dA(t) - AgA(t) i' l A dA(t)

J #

fl- A -A # pt A A(t) 0 o

-t A+A Ir ,

'd A(t) = Aoe Where - t = 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> = 7200 sec I gpm Ir Volume of RCS 1

E 1 n 3' ' . ,.

1 min j y , _mm._ _ _

tr 3 7.48 , gal , ,60 .sec 12062 R ,

-I

= 1.85E - 7 sec

d. Since the isotope activity is r.Mumed to remain evenly distributed throughout the RCS volume, then the rate at which the isotope activity leaks from the RCS, R(t), is simply the RCS leak rate times the activif y. The total activity released during a given time intervalis the integration of the release rate over that interval,in this case,2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

- R(t) = 4 x A(t)

R(t)= 4 x Ag'(4'AI R(t)dt = 4A,cI4'4Idt 0 0 dt

= (4 A'- 4 + Ah (4 +4)e(4'AI R = ((4^" 44) (1-e(4*AI) Equation 2.d

~

l REVISION NO : 4 l e - . - . -

l

  • l l

COMMONWEALTH EDISON COMPANY

- l CALCULATION NO. BRW-97-0798 M PROJECT NO. PAGE NO.14 I TABLE 2.d Isd p car A%;

RCS Activity at 60 Constant,b. . . Released, RC Nuclide :- Cl/g J(Design input 12); (Equation 2.d):

d

- [sec ]

[CQ <

l131 9.36E3 9.07E-7 1.24E1 1132 1.05E4 8.37E 5 1.05E1 1133 1.50E4 9.25E-6 1.93E1 1134 2.25E3 2.20E-4 1.50E0 1135 8.23E3 2.91E 5 9.88E0

e. C6:culate the 0-2 hour thyroid Inhalation dose at the Exclusion Area Boundary (EAB) in accordance with UFSAR equation 15A 2.

TABLE 2.e Activity 'I -

Weighted Activity:

" - Released, Rix DCF[

Nuclide - - Reletsed, Rs

-D F ( inpu (Table 2.d). [Ci] 24) [ rem /CU I"*l l131 1.24E1 1.08E6 1.34E7 1132 - 1.05E1 6.44E3 6.76E4 l133 1.93E1 1.80E5 3.47E6 l-134 1.50E0 1.07E3 1.60E3 1-135 9.88E0 3.13E4 3.09ES Total I(RixDCFilaAs 1.72E7 The total DE l-131 activity released is the weight"d activity from Table 2.e divided by the 1-131 dose conversion factor. Numerically this is 15.9 u DE l 131 (1.72E7 rem /1.08E6 rem /CI). -The breathing rate is based on 0-8 hour time period.

Exclusion Area Boundary Dose for 0-2 hours for a 1 aom feak rate r >

Dm(rem)= E xBx (R, x DCF,) _ Equation 2.e.1 (Qsm

= 7.7E - 4 x 3.47E -4 x1.72E7(rem) tm , ,sec,

= 4.60(rem) l REVISION NO.: 4 l w

l I

COMMONWEALTH EDISON COMPANY l CALCULATION NO. BRW 97-0798-M PROJECT NO. PAGE NO.15 - l

f. Calculate the thyroid inhalation dose at the Low Population Zone (LPZ) using the equation from UFSAR Section 15A.4. The activity released during the accident from 2-40 hours was obtained from UFSAR Table 15.1-4 (as amended in Ref. 22). This activity includes the dose contribution from a 9.4 gpm pnmary-to-secondary leakage and the secondary side release.

TABLE 2.f.1 1 0 Dose 40 HourWeightedh RCS lodine Activity .

Nuclide Released, R4, (UFSARi ;D F Activity Released,(

g p Table 15.1-4) . [Ci] ~ Rix DCF6 [ rem]:

24)[ rem /Ci]

1131 1.9E3 1.08E6 2.05E9 l-132 3.8E1 6.44E3 - 2.45ES l133 1.8E3 1.80E5 3.24E8 l134 3.7E0 1.07E3 3.96E3 1-135 3.8E2 3.13E4 1.19E7

Total I(R4 x DCFF 2.39E9

. The total 2 40 hour4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> weighted activity calculated above in Table 2.f.1 is separated into specific time periods of 2-8 hrs,8-24 hrs,24-40 hrs. This is t, sed on scaling the total 2-40 hour weighted activity by the fraction of steam released during the same time period. The 2-40 hour steam release was obtained from UFSAR Table 15.13.

i TABLE 2.f.2 Steam Release, Fraction of Total: L-We g ted Act yD eig d A@W Time Period . (UFSAR Table Steam Release Released in Time v for Time period . Re d able

- 15.1-3) [lb] Period [ rem]j l 2 )

2 8 hr 939.604 0.30 2.39E9 7.17E8 8-24 hr 1,234,515 0.39 2.39E9 9.32E8 24-40 hr 980.806 0.31 2.39E9 7.41E8

!. Total Steam - Total Weighted ;

3,154,925 2.39E9 i Release Activity Released i

The atmospheric dilution factors (X/Q) for 0-8 hrs,8-24 hrs, and 24-40 hrs were obtained from l

UFSAR Table 15.0-14. The breathing rates for 0-8 hrs,8-24 hrs and 24 40 hrs were obtained

! from UFSAR Table 15A 1. Calculate the thyroid inhalation dose at the Low Population Zone (LPZ) using the equation from UFSAR Secilon 15A.4.

r S Dm[ rem] =

8- x B x[(R ,<i DCF,) Equation 2.f.1

<Qsm

- l REVISION NO.: 4' l

-em- " - ,,,e m - p ,- , - a _ - m-- , - -..m-- - 3,n,-- s.

k i

COMMONWEALTH EDISON COMPANY l CALCULATION NO. BRW 97-0798 M PROJECT NO. PAGE NO.16 l TABLE 2.f.3 Atmos. .

. Weighted -

Dispersion Breathing Rate, Activity LPZ Dose, Dm,;

Time Factor, X/Q, B,(UFSAR ' . Released, : Jw/ 9.4 gpm Leak' Period . (UFSAR Table Table 15A-1) . . IRixDCFi. Rate (Equationd 15.0-14)- [m*/sec] ~ (Table 2.f.2) : 2.f.1) [ rem]

- [sec/m*] - '[rern) 0 2 hr 7.1E 5 3.47E 4 1.67EB* 4.11 2-8 hr 7.1E-5 3.47E-4 7.17E8 17.68 8-24 1.4E-5 1.75E-4 9.23E8 2.28 24-40 7.1 E-6 2.32E-4 7.41E8 1.22

' Total LPZ Dose:

w/ 9.4 gpm Leak 25.27 Rate [ rem]

  • From Tables 2 e and 1 c [(172E7x9 4) + (3 94E6 + 16SE6) = 167E8]
3. CALCULATION OF DOSE DUE TO PRIMARY TO SECONDARY LEAKAGE DURING ACCIDENT INITI ATED LPIKE The accident initiated spike model is the same as the pre-accident modct except an additional iodine appearance rate term is added for fuel release rate lato the RCS. In accordance with the Standard Review Plan, the reactor trip and/or primary system depressurization associated with the MSLB creates an iodine spike in the primary system. The spiking model assumes that the iodine release rate from the fuel rods to the primary coolant increases to a value 500 times greater than the Technical Specification tirait. This factor adds an additional release rate factor for lodine activity, Aw.
a. Calculate the total removal rate of iodine, Ai , through letdown purification and radioactive decay.

Equation 2 of Reference 18 defines this total as:

Ahec")= Aw'pec"j+ A,(sec") Equation 3.a.1 F, , 3 Where : Am sec" = x 1- Equation 3.a.2 l REVISION NO.: 4 l et

_ . _ _ _ . _ _ _ __ _ . _ . _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ .____.__m_,____.________ . _ _ _ _ _ _ _ . _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _

+ /

f COMMONWEALTH EDISON COMPANY l CALCULATION NO. BRW 97-0798-M PROJECT NO. PAGE NO.17 l-The 75 gpm letdown purification flow, F,, is converted from gpm to grams /sec at letdown design parameters (Design inputs 2 and 3).

~

E" I "

p',_g --

sec,

= 75' _minj x

_7.48 gal, x

_0.01613n' ,

x

_ lb _

x

_60 sec,

= 4704 1 sec_

Substituting the values of F,, M and DFinto Equation 3.a.2 gives :

8 4704 --

e 3 43sec= 2.42E8(g.

-8C : xl1 s 10s

= 1.75E - 5 sec~'

TABLE 3.a Letdown Parif. Isotope Decay Total lodine Removal Constant, . Constant,14 Removal Rate, A, Nuclide At o,(Equation 3.a.2)- (Design input 12) Equation 3.a.1

[sec"1 [sec"] [sec"] ~

l131 1.75E 5 9.97E-7 1.85E 5 i132 1.75E-5 8.37E-5 1.01 E-4 1133 1.75E-5 9.25E-6 2.67E-5 1134 1.75E 5 2.20E-4 2.38E-4 1135 1.75E 5 2.91E-5 4.66E 5

b. The equilibrium fuel release rate,6, is defined as the product of the RCS activity at 1 Cl/g DE l-131 (from Table 2.b) and the total lodine removal rate for each isotope:

6 [Cl/sec] = A [Ci] x Ae [sec"] Equation 3.b i

l REVISION NO.: 4 l

- - - - -__-____m . _ , _ _ _ _ _ _ __ _ _ . _ _ _ _ _ _ __ _ _ _ _ _ _ . _ _ _ _ _ _ _ . _ __

COMMONWEALTH EDISON COMPANY l CALCULATION NO. BRW-97-0798-M PROJECT NO. PAGE NO.18 l Each equilibrium fuel release rate is multiplied by 500 (Design input 22) to obtain the spiked release rate.

Table 3.

Totallodine Fuen helease - . . Spiked :

Removal Rate,4 Rate, h Release Rate Nuclide 500 x& ,

(Table d3.a)1 .( Equation 3.b)

[sec ] [Ci/sec] ' [Cl/sec) 1131 1.85E 5 2.89E 3 1.45 l-132 1.01 E-4 1.77E-2 8.85 l133 2.67E 5 6.67E-3 3.34 l-134 2.38 E- , 8.92E 3 4.46 l135 4.66E 5 6.39E 3 3.20

c. Neglecting the loss terms (radiodecay, leakage and letdown), the time dependent RCS activity due to the accident initiated iodine spike may be written as:

dA(t) dt

= 500(

^ . '.

dA(t) = 500(dt 1, 'o A(t)= A, + 500bt Equation 3.c

d. Since the isotope activity, A(t) is assumed to remain evenly distributed throughout tne RCS volume, then the rate at which the isotope activity leaks from the RCS, R(t), is the RCS leak rate constant, L,, multipl6d by the activity determined by Equation 3.c. Tiie total activity released during the event is calculated by integrating the release rate over the time interval.

R(t) = 4 A(t)

= 4(A, + 500(t)

R(t)dt = '4(A, + f00(t)dt 0 0 R=4 A,t + 5004"[)

.2 Equation 3.d

(

l REVISION NO.: 4 l

COMMONWEALTH EDISON COMPANY l CALCULATION NO. BRW 97-0798 M PROJECT NO. PAGE NO.19 l TABLE 3.d AcWW at : S iked Release Mate 0-2 Hour ActW Nuclide - 1 pCi/g, A. Rekased,4

. (Table 3'b) [Cl/sec) . (Equation 3.d) [C0 .

(Table 2.b) [C0 l-131 156.1 1.45 7.16 l132 174.8 8.85 4.27E1 8133 249.7 3.34 1.63E1 1134 37.5 4.46 2.14E1 1-135 137.3 3.20 l 1.55E1

e. Calculate the thyroid inhalation dose at the Exclusion Area Boundary and Low Population Zone in accordance with UFSAR equation 15A-2.

TABLE 3.e Nuclide 0-2 Hour Achty Released, DCFi DDC4 Re (Table 3.d) [Ci] [ rem /Cil [ rem]~

l131 7.16 1.08E6 7.73E6 l-132- 4.27E1 6.44E3 2.75E5 l133 1.63E1 1.80E5 2.93E6 l-134 2.14E1 1.07E3 2.29E4 l-135 1.55E1 3.13E4 4.85ES I(RixDCFi) 1.14E7 The total DE l-131 activity released in 0-2 hours is the total weighted activity released, I(R,xDCF,), from Table 3.e divided by the 1131 dose conversion factor. Numerically this is 10.6 Cl DE l-131 released in the first two hours (1.14E7 rem /1.08E6 rem /Cl). The breathing rate is based on the 0-8 hour time period.

Exclusion Area Boundary Dose for a 1 com leak rate:

r i Dm[ rem)= E xBx (Ri xDCE) Equation 3.e.1

< Q n.a 3-

= 7.7E - 4 $ x 3.47E - 4 *- xl.14E7(rem)

-M. _ SCC ,

= 3.05 (rem] ,

l REVISION NO.: 4 l

e COMMONWEALTH EDISON COMPANY

- l CALCULATION NO. BRW 97-0798 M PROJECT NO. PAGE NO. 20 - l

f. Calculate the thyroid inhalation dose at the Low Population Zone (LPZ) using the equation from -

UFSAR Section 15A.4. The activity released during the accident from 2-40 hours was obtained from UFSAR Table 15.14 (as amended in Ref. 22). This activity includes the dose contribution from a 9.4 gpm primary-to-secondary leakage and the secondary side release.

TABLE 3.f.1 RCS lodine Activityi 2 40 Hour Weighted L Nuclide Released, R4, (UFSAR - pu{  ; Activity Released 1 Table 15.1-4)-[Ci]

-D

'( g

Rix DCF,[i rem]i 24)[ rem /Cir '

1131 2.1 E3 1.08E6 2.27E9 l-132 1.0E3 6.44E3 C.44E6 l133 2.9E3 1.80E5 5.22E8 l134 1.4E2 1.07E3 1.50E5 l135 1.2E3 3.13E4 3.76E7 TotalI(Rix DCF.) 2.84E9 The total 2-40 hour weighted activity released calculated above in Table 3.f.1 is separated into specific time periods of 2-8 hrs,8-24 hrs, and 24-40 hrs. This is based on scaling the total 2 40 hour4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> weighted activity released by the fraction of steam released during the same time period.

The 2-40 hour steam release was obtained from UFSAR Table 15.13.

TABLE 3.f.2 o 2 Steam Release,- Fraction of Total . Weighted' Activity g d Time Period (UFSAR Table Steam Release -- "

Released in Time 1 I* #

15.1-3) [lb) for Time Period b ' ' 3, "$ Period [ rem]d <

2-8hr 939,604 0.30 2.84E9 8.52E8 8-24 hr 1,234,515 0.39 2.84E9 1.11E9 24 40 hr 980,806 0.31 2.84E9 8.80E8 Total Steam - Total Weighted ? '

3.154,925 .84E9 Release Activity Released 4 The atmospheric dilution factors (X/Q) for 0-8 hrs,8-24 hrs, and 24 40 hrs were obtained from

. UFSAR Table 15.0-14. The breathing rates for 0-8 hrs,8 24 hrs and 2440 hrs were obtained from UT'SAR Table 15A 1. Calculate the thyroid inhalation dose at the Low Population Zone (LPZ) using the equation from UFSAR Section 15A.4.

- l REVISION NO.: 4 l

O 4

COMMONWEALTH EDISON COMPANY

@^LCULATION NO. BRW.97 0798 M PROJECT NO. PAGE NO. 21 l

< s D,n[ rem]= L x B x { {R, x DCF,) Equation 3.f.1 sQsm TABLE 3.f.3 .,

Wel hted Activity Dis rs on Breathing Rate, LPZ Dose, Dm, w/ -

Time Factor X/Q. B, (UFSAR '

- a 9.4 gpm Leak

@ixDCFi),'  ;

Period - (UFSAR Table Table 15A 1) Rate (Equation (Table 3.f.2) 3,g,q g g,,,)

15.0 14) [m'/sec]

[sec/m*] I*I 0 2 hr 7.1E 5 3.47E 4 1.13E8' 2.78 2 8 hr 7.1E 5 3.47E 4 8.52E8 20.99 8 24 1.4E 5 1.75E-4 1.11E9 2.72 24 40 7.1E 6 2.32E-4 8.80E8 ,

1.45 Total LPZ Dose w/ a 9.4 Leak 27.94 Rate [ rem] ~

  • From Tables 3.e and 1.c [(1.14E7x9.4) + (3.94E0 + 1.68E+6) = 1.13E8)
4. CALCULATION OF SITE ALLOWABLE LEAK RATE
a. Results of the Pre Accident lodine Spike Model The EAB dose for a 9.4 gptr leak rate is 44.74 rem (4.60 X 9.4+1.50). Tho total LPZ dose calculated in Table 2.f.3 is 25.27 rem. Therefore, the EAB dose is more limiting.

The thyroid dose due to the release of activity in the secondary side of all four steam generators is 150 rem (page 10). The dose due to 1 gpm primary to secondary leakage in 4 steam generators with a concentration of 60 Cl/g is 4.60 rem (page14). Given that the dose limi' in the Standard Review Plan is 300 rem for the pre-accident model, the maximum allowable leak rate without exceeding 300 rem is:

f S

'""~ '*

Allowable Leak Rate =

4.60 *

s gpm j

= 64.89 gpm l REVISION NO.: 4 l l

a e

i l

COMMONWEALTH EDISON COMPANY l CALCULATION NO. BRW 97 0798 M PROJECT NO. PAGE NO. 22 l Consequently, the total EAB dose due to a 64.89 gpm leak during a MSLB is 300 rem. Allowing 0.1 gpm room temperature leakage per each of the three intact steam generators leaves 64.47 gpm (64.89-0.3x1.406) for the faultr.td loop.

Note that the 64.89 gpm allowable leak rate is calculated at RCS operating conditions. Should the allowable leak rate be desired to be expressed at room temperature conditions, the 64.89 gpm must be divided by 1.406 (Reference 19) to account for RCS density differences.

Therefore, the room temperature allowable leak rate is 46.15 gpm.

b. Results of the Accident initiated lodine Spike Model The EAB dose for a 9.4 gpm leak rate is 30.17 rem (3.05 x 9.4+1.5). The total LPZ dose calculated in Table 3.f.3 is 27.94 rem. Therefore, the EAB dose is more limiting.

The thyroid dose due to the release of activity in the secondary side of all four steam generators is 1.50 rem (page 10). The dose due to i gpm primary to secondary leakage in 4 steam generators with a concentration of 1 Cl/g is 3.05 rem (page 19). Given that the dose limit in the Standard Review Plan is 30 rem for the accident initiated spike model, the maximum allowable leak rate without exceeding 30 rem is:

r >

Allowable Leak Rate =

3.05 '**

( 8Pm ,

= 9.34 gpm Const.quently, the total EAB dose duo to a 9.34 gpm leak during a MSLB is 30 rem. Allowing 0.1 gpm room temperature leakage per each of the three intact steam generators leaves 8.92 gpna (9.34-0.3x1.406) for the faulted loop.

Note that the 9.34 gpm allowable leak rate is calculated at RCS operating conditions. Should the allowable leak rate be desired to be expre:; sed at room temperature conditions, the 9.34 gpm must be divided by 1.406 (Reference 19) to accourt for RCS density differences. Therefore, the room temperature allowable leak rate is 6.64 gpm.

l REVISION NO.: 4 _]

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

P COMMONWEALTH EDISON COMPANY

- l CALCULATION NO. BRW 97-0798-M PROJEC1 NO. PAGE NO. 23 l -

5. CALCULATION OF END-OF CYCLE 7 PREDICTED DOSES In accordance with the requirements for Braidwood Unit i voltage based reosir criteria (IPC) for outer '

diameter stress corrosion cracking at tube support plates, the potential tube leakage during a MSLB event with containment bypass must be predicted at the end of the next operating period. This predicted l leak rate must be compared to hKl shown to be less than the maximum site allowable leak rate determined in Section 4 above.-

Braidwood Station is currently preparing a request for Technical Specification change to lower the RCS i Dose Equivalent lodine -131 limit to 0.05 C1/g. As documented in Section 3, the site allowable leak l rate of 6.64 gpm at room temperature conditions is based on an RCS DE 1131 limit of 1 Cl/g. The site allowable leak rate can be increased proportional to a reduction in RCS DE 1131. Therefore by reducing <

the RCS DE 1131 limit to 0.05 Cl/g, the tillowable leak rate at room temperature conditions is increased l to 132.8 gpm (5.64 gpm/0.05). I The predicted end of cycle 7 leak rate is 122 gpm based on room temperature conditions (Design input 25). To this is added operational leakage from three steam generators (0.1 gpm per steam generator) for a total leek rate of 122.3 gpm at room temperature conditions. This is bounded by the requested 132.8 gpm site aKowable leak rate limit at room temperature conditions.

This section of the calculation determines the EAB and LPZ thyroid dose for the prwiued end-of-cycle leak rate of 122.3 gpm to validate that the current operating conditions are bounded by existing calculations. The EAB and LPZ dose is bounded by Section 3 of this document, which showed that the l accident initiated spike is the limiting accident,

a. The most restrictive EAB thyroid dose limit is 30 ram pei section 4.b (page 22). This dose limit corresponds to an allowable leak rate of 6.64 gpm at an RCS DE l 131 concentration of 1 Cl/g.

The calculated EAB dose remains the same when allowable leakage is increased to 132.8 gpm because RCS DE l 131 is decreased by a proportional amount. The EAB dose, Xm, due to current cycle projected leakage of 122.3 gpm is calculated by performing a ratio of .alculated values to projected values.

122.3 gpm Xw 132.8 gpm 30 rem X, = 122.3 gpm-30 rem -

132.8 gpm Xm = 27.63 rem at a 0.05 p Ci/g RCS DE 1131 concentration Therefore, the end of cycle 7 predicted EAB dose is within the 30 rem dose limit under end-of-cycle 7 operating conditions, i

l REVISION NO.: 4- l 5

l f

COMMONWEALTH EDISON COMPANY l CALCULATION NO. BRW 97-0798 M PROJECT NO. PAGE NO. 24 l

b. The LPZ calculated thyroid dose is 27.94 rem per Section 3.f (page 21). This dose limit corresponds to an allowable leak rate of 6.64 gpm at an RCS DE l 131 concentration of 1 pCL/g, which agaln remains the same under the proposed allowable leak rate of 132.6 gpm because RCS DE l 131 is reduced to 0.05 pC1/g DE l 131. The LPZ dose for projected end-of-cycle conditions, Xm, is calculated by perfc' ming a ratio of calculated values to projected values.

122.3 gpm , Xnt 132.8 gpm 27.94 rem X ' EE* 27.94 rem m = 132.8 gpm Xtn = 25.73 rem at a 0.05 Ci/g RCS DE I-131 concentration The ., fore, the end of cycle 7 predicted LPZ dose is within the 30 rem dose limit under end-of-cycle 7 operating conditions.

SUMMARY

AND CONCLUSIONS It is concluded from Section 4 that the accident initiated spike is more limiting, therefore the maximum site allowable SG leak rate during a postulated MSLB is 9.3 gpm a'. RCS operating conditions (6.6 gpm at room temperature) with a RCS DE l 131 concentration of 1 pCl/g. This value includes the 0.1 gpm contribution from each of the three intact SGs.

Section 5 determined that the Unit i end of cycle 7 predicted MSLB tube leakage results in off site thyroid doses that are less than a small fraction (10%) of 10CFR100 limits. The ra=ultino EAB and LPZ doses, with a 0.05 pCilg RCS DE l 131 limit, are 27.63 rem and 25.73 rem, respectively, which are less than the 30 rem limit for the limiting accident initiated spike case.

FINAL -

6 I

- REVISION NO.: 4 l

_ _ ___ .. . . .

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