ML20210P160

Rev 1 to ATD-0410, Allowable Leakrate Calculation for Steam Generator Interim Plugging Criteria

ML20210P160
Person / Time
Site:	Byron, Braidwood
Issue date:	08/21/1997
From:	Lahti G, Perchiazzi W COMMONWEALTH EDISON CO.
To:
Shared Package
ML20210P150	List: ML20210P147 ML20210P160
References
ATD-0410, ATD-0410-R01, ATD-410, ATD-410-R1, NUDOCS 9708260456
Download: ML20210P160 (23)

Text

- . _ . - - _ - _

l'. , Exhibit C COMMONWEALTH EDISON COMPANY NEP 12 02

/> - .

CalculatlOn Title Page Revision 4 Page 1 ef 2 CALCULATION NO : ATD 0410 PAGE NO : 1 X SAFETY RELATED 0 REGULATORY RELATED 0 NON SAFETY RELATED CALCULATION TITLE: ALLOWABLE LEAKRATE CALCULATION FOR STEAM GENERATOR INTERIM PLUGGING CRITERIA STATION / UNIT BYRON 1 SYSTEM ABBREVIATION: RC. MS EQUIPMENT NO (IF APPL ): 1RC01BA!B/C/D PROJECT NO. (IF APPL ) N/A REV :1 STATUS. APPROVED QA SERIAL NO. OR CHRON NO. DATE 8/21/97 PREPARED BY. M. MARCHIONDA/ [/~ [d1H _b *mb lAl#'O DATE.

J. SMITH / k% M DATE: 3[2/,/i'7 REVISION

SUMMARY

THIS CALCULATION DETERMINES THE MAXIMUM SITE ALLOWABLE LEAKRATE FOR STEAM GENERATOR TUBE LEAKAGE USING 24% PLUGGING CRITERIA DESIGN PARAMETERS ELECTRONIC CALCULATION DATA FILES REVISED.

(Name ext / size /date/ hour /: min /venfication method / remarks)

None DO ANY ASSUMPTIONS IN THIS CALCULATION REQUIRE LATER VERIFICATION?

O YES X NO i a W '7'[ /, O /

REVIEWED BY: G hl 8///

v V ' ///'

/ f ~

DATE: 2/ M /ff7 REVIEW METHOD- Detailed Review COMMENTS (C, NC OR Cl): CJ APPROVEDBY.W PERCHIAZZI/ [d[8% / [ #,, DATE: fdi/f/

9708260456 970021 PDR ADOCK 05000454 P PDR

I, * '., Exhibit C i**,* NEP.12 02 Revision 4 Page 2 ef 2 COMMONWEALTH EDISON COMPANY CALCULATION REVISION PAGE CALCULATION NO. ATD-0410 PAGE NO.: 2 REV.1 STATUS Approved QA SERIAL NO. OR CHRON NO. DATE: 8/21/97 PREPARED BY DATE:

REVISION

SUMMARY

ELECTRONIC CALCULATION DATA FILES REVISED (Name ext /sizeldate/ hour: min /venfication method / remarks)

DO ANY ASSUMPTIONS IN THIS CALCULATION REQUIRE LATER VERIFICATION O YES O NO REVIEWED BY: DATE:

REVIEW METHOD: CCMMENTS (C, NC or Cl):

APPROVED BY: DATE:

, - . ., Exhibit D NEP-12 02 Revision 4

.- COMMONWEALTH EDISON COMPANY CALCULATION TABLE OF CONTENTS -

PROJECT NO, CALCULATION NO. ATD-0410 REV. NO. 1 PAGE NO. 3 DESCRIPTION : SG Allowable Leakrate Caciutation PAGE NO. SUB-PAGE NO.

TITLE PAGE 1 REVISION

SUMMARY

TABLE OF CONTENTS 3

< PURPOSE / OBJECTIVE 4 METHODOLOGY AND ACCEPTANCE CRITERIA 4

ASSUMPTIONS 5 I

0 DESIGN INPUT 6

REFERENCES CALCULATIONS 8

SUMMARY

AND CONCLUSIONS 23 t

.. Exhibit E N E P.12-02 Revision 4 COMMONWEALTH EDISON COMPANY l CALCULATION NO. : ATD-0410 PROJECT NO. PAGE NO,4 l PURPOSE AND OBJECTIVE:

The purpose of this calculation is 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 accident initiated lodine spiko. The release of iodine and the resulting thyroid dose at the Exclusion Area Boundary and Low Population Zone were considered in the leak rate determination. Whole body dose due to noble gas immersion is less limiting thari thyroid dose as documented in UFSAR Table 15.011.

Given the large margin to the 25 rem whole body dose limit, whole body dose was not re-evaluated.

METHODOLOGY AND ACCEPTANCE CRITERIA:

The Main Steam Line Break (MSLB) accident is considered the most limiting off site dose accident because the event causes a sustained large pressure difference across the steam generator tubes providing a motive force for steam release. The Technical Specification limit for steam generator (SG) tubs leakage is 150 gpd (0.1 gpm) for each SG. The dose attributed to a 1 gpm leak rate from the reactor coclant system was calculated. This value was then used to determine the ahwable 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 Jean established in the secondary coolant prior to the accident, and

2. The release of ths primary coolant iodine 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 lodine concentrations, which is consistent with the Technical Specification definition of dose equivalent iodino. The TID values are based on ICRP *'., . ' Permissible Dose for Intemal Radiation,1959.*

The off-site dose assessment uses ICRP 30, "Limite for intakes of Rdonuclides by 'Notkers, 1979* dose conversion factors. ICRP 30 is also the basis for Federal Guidance Report No.11,

" Limiting Values of Radionuclide intake and Air Concentration and Dose Conversion Factors for Inhalation, Submersion, and Ingestion,' dated 1988. This report provides the dose conversion factors for the Station's Off-site Dose Calculation Manual for inhalation dose at the site boundary due to airbome effluents.

The dose Acceptance Cnteria 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 iodine spike, the calculated doses should not exceed 'he guideline volues 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.

l REVISION NO.: 1 l

l

,,, .. Exhibit E

. NEP 12 02 Revision 4 COMMONWEALTH EDISON COMPANY l CALCULATION NO. : ATD 0410 PROJECT NO. PAGE NO. 5 l ASSUMPTIONS

1) The effect of boron 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 ft' (Reference 1)

2. The full power RCS temperature and pressure are 586.2 *F and 2250 psia. (Ref 1 and 2)

3. The RCS specific volume at full power is 0.02258 ft'/lbm. (Ref. 3) d

4. The lodine decay constant for 1131 is 9.96E 7 sec (Ref. 4)

5. The Purification System temperature and pressure are 110 ft' and 370 psia (Ref 5).

6. The Purification System specific volume is 0.01615 ft'/lbm. (Ref. 3)

7. Breathing rate is '3.47E 4 m'/sec. (Ref. 6)

8. Atmospheric Dilution Factors, X/Q, are taken from UFSAR Table 15.0-13. (Ref.7)

v. 9. RCS lodine concentrations are based on UFSAR Table 11.12 without the 1% teled fuel contribution. (Ref. 8)

10. The in tial steam release from the defective and intact steam generators are taken from UFSAR Table 15.13. (Ref. 9)

11. The secondary side faulted steam generator has a partition fraction of 1.0 and the intact steam generators have partition fraction of 0.1. (Reference 15)

12. The half life for I 131 is 8.04 days,1132 is 2.30 hrs, i 133 is 20.8 hrs. I 134 is 52.6 min, and I 135 is 6.61 hrs. (Ref.21)

13. The initial primary coolant activity dose equivalent iodine concentration is 60 Cilg (Ref.

12)

14. The initial secondary coolant activity is 0.1 Cilg. (Ref.12)

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.12)

16. No fuel failure attributable to the accident is assumed. (Ref.12) 17, lodine partition coefficients for all SGs are 1.0 for primary-to secondary leakage. (Ref.

15)

18. Normalletdown purification flow is 75 gpm. (Ref 11) l REVISION NO.: 1 l

2. . Exhibit E

- N E P-13-03 Revision 4 COMMONWEALTH EDISON COMPANY l CALCULATION NO, : ATD 0410 PROJECT NO, PAGE NO. 6 l

19. Letdown temperature is 115'F and 2250 psia. (Ref 11)

20. Specific volume of letdown is 0.01608 ft'/lbm. (Ref 3) 21, Decon Factor, DF, for mixed bed demineralizer is 10. (Ref 13)

22. The iodine release rate spike factor is 500. (Ref 12)

REFERENCES:

1) B/B UFSAR Table 11.1 1, devision 0

2) B/B UFSAR Table 5.1 1, Revision 0

3) ASME Steam Table, Fifth Edition

4) The Health Physics and Radiological Health Handbook, Revised Edition, Revised

5) Byron Operating Procedures BOP CV 17. Rev 7 and BOP CV 9, Rev.2.

6) B/B UFSAR Table 15A 1, Revision 0

7) B/B UFSAR Table 15.0-13, Revision 0

8) B/B UFSAR Table 11.12, Revision 0

9) B/B UFSAR Table 15.13, Revision 6

10) Introductorf Nuclear Physics by Kenneth S. Krane,1988

11) B/B UFSAR Table 9.3-2, Revision 0

12) Standard Review Plan (NUREG 0800),15.1.5 Appendix A

13) B/B UFSAR page 9.3-43 Revision 0

14) Techi,! cal Specifications 3.4.8 (Amendment 77),3.7.1.4 (Original), 3.4.6.2 (Amendment 67)

15) WCAP 14046, "Braidwood 1 Technical Support for Cycle 5 Steam Generator Intenm Plugging Criteria,' dated May,1994.

16) ICRP Publicatica 2. Report of Committee 11 on Permissible Dose for Internal Radiation, 1959

17) ICRP Publication 30, Limits for intakes of Radionuclides by Workers,1979

18) Adams and Atwood Report,"The lodine Spike Release Rate During a Steam Generator Tube Rupture,' October 16,1990 .

[_ REVISION NO : 1 l

, .. Exhibit E

. NEP-12 03 Revision 4 COMMONWEALTH EDISON COMPANY l CALCULATION NO, : ATD-0410 PROJECT NO, PAGE NO. 7 l

19) Westinghouse Letter CAE 97171, dated July 21,1997, pertaining to the Reador 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) Radioactive Decay Data Tables: A Handbook of Decay Data For Application to Radiation Dosimetry and Rad'ntogical Assessments,1981 VARIABLE AND CONSTANT DEFINITIONS:

M RCS mass [lbm]

M.r. Steam Generator steam release mass [lb)

V RCS volume [ft']

v RCS specific volume [ft*/lbm]

L, RCS leak rate constant [sec"]

6 Fuel Release constant [Cl/sec]

Ao isotope Decay Constant [sec"]

Ao Letdown Purification Removal Constant [sec")

h Total lodine Removal Rate (sec"]

t Time [sec]

A, RCS iodine activity [Ci]

C, lodine Concentration [Cl/g or Ci/g]

C, initial lodine Concentration [Cl/g or Ci/g]

F. Letdown Purification Flow [g/sec)

Qi Activity Released of nuclide,I[Ci]

R. Activity Released of nuclide,I[Ci]

D Thyroid Inhalation Dose [ rem]

3 B Breathing Rate [m /sec)

X/O Atmospheric Dilution Factor [sec/m']

DEFINE UNITS:

Ci = 1 Curie Ci = 1E-6 Cl 1 lbm = 454 g i ft' = 7.48 gal 1 min = 60 sec

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 ride activity is conservatively taken as the Technical Specification limit of 0.1 pCilg (Reference 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 (Reference 9) which is the entire initial SG water mass. The faulted SG is assumed to l REVISION NO.: 1 l

. Exhibit E

• NEP-12 02 Revision 4 i COMMONWEALTH EDISON COMPANY  ;

l CALCULATION NO. : ATD 0410 PROJECT NO. PAGE NO. 8 l 1

steam dry in 10-15 minutes so all of the iodine is available for release. The combined 0 2 hr steam release for the three intact steam generators is 406,716 lbs (Reference 9). The combined 2 8 hr steam release for the three intact SGs is 939.604 lbs (Reference 9). The three intact SGs a partition factor of 0.1 is used (Design input 11),

a. The iodine concentrations are obtained from UFSAR Table 15.0-9 and are converted to Cl/lb. since the steam release is defined in Ibs.

C =C o r454 =1E-6 Equation 1.a TABLE 1.a

. Nuclide . lodine Concentration, C.,. lodine Concentration, C ,

(UFSAR Table 15.0 9);  : (Equation .1 a)

[pCile]' - [CMb] >

l131 0.066 3.00E 5 l132 0.024 1.09E 5 l133 0.106 4.81E 5 1134 0.016 7.26E-6 l-135 0.058 2.63E 5 l REVISION NO.: 1 l

1 I". . Exhibit E NEP-la-02 Revision 4 COMMONWEALTH EDISON COMPANY l CALCULATION NO. : ATD-0410 PROJECT NO. PAGE NO. 9 I

b. The iodine concentration for each nuclide, Ci 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) to obtain the total amount of curies available to be .wleased, Ai, for 0-2 hours. The activity available for release in the intact SGs is then multiplied by the partition factor. 0.1, to determine the amount of activity actually released.

A'*""d (Ci] = C, x M'*","d (Ib] r 1.0 Equation 1.b.1 Ib ,

A7'*"(Cl) = C, x M'"l,*n* (Ib] x 0.1 Equation i b.2 Ib, TABLE 1.b _

Nuclide ActMty Released from Activity Released from Faulted 89 A". Intact 80s (0 2 hrs), AP,

^ (Equation 1.b.1) [CQ  ; (Equation 1.b.2) [CG l131 2.88E0 1.22E0 1132 1.05E0 4.43E 1 1133 4.62E0 1.96E0 1134 6.97E 1 2.95E 1

~

I.135 2.52E0 1.07E0

c. The activity releaseo, A, determined above, is multiplied by the ICRP 30 Dose Conversion Factor, DCF i , (Reference 16) for each iodine isotope and then summed separately for the faulted SG and intact SGs.

Of*""d(rem) = A[*""d(Ci]x DCF, Equation 1.c.1

, Cl I*

Df'*"(rem] = Af'*d(Ci]x DCF, Equation 1.c.2 Ci ,

l REVISION NO.: 1 l l

.. l Exhibit E  !

N EP-12-02 Revision 4 COMMONWEALTH EDISON COMPANY l CALCULATION NO. : ATD-0410 PROJECT NO. PAGE NO.10 l TABLE 1.c

-. Nuclide - ICRP-30 Dose Does from Faulted Does from Intact SGs, conversion Factor, .

80, D". ._ . _ , . ._ D",(0-2 hrs) .

OCFi,(Reference 17). . (Equat60n 1.c.1) (rom] (Equation 1.c,2) (rem]

[ rem /CG l131 1.08E6 3.11 E6 1.32E6 l132 6.44E3 6.76E3 2.85E3 1133 1.80E5 8.32E5 3.53E5 l134 1.07E3 7.46E2 3.16E2 l135 3.13E4 7.89E4 3.35E4

' Total (IOM)L 4.03E6 1.71 E6 The 0-2 hour exclusion area boundary total dose released from the faulted and the three intact SGs is 5.74E6 rera (4.03E6 + 1.71E6 rem). This total dose can also be defined as LD,xDCF,.

The total DE l 131 activity released is the total dose from Table 1.c divided by the 1131 dose conversion factor. Numerically this is 1.58 CI(1.71E6 rem /1.08E6 rem /ci)

d. The off site thyroid inhalation dose at the exclusion area boundary, Das, and at the low population zone, O tp:, are calculated in accordance with UFS AR equation

15. A.4, Exclusion Area Boundary Dose (0-2 hours)

<p Du3(rem) =

x B V D, x DCF, Equation 1.d.1 s 0 sus

= 5.7E - 4 x 3.47E - 4 x 5.74E6[ rem]

.m sec ,

= 1.14 (rem)

J l REVISION NO.: 1 l

Exhibit E

?,- N E P-13-02 Revision 4 COMMONWEALTH EDISON COMPANY l CALCULAT!ON NO. : ATD 0410 PROJECT NO. PAGE NO.11 l

2. CALCULATION OF DOSE DUE TO PRIMARY-TO SECONDARY LEAKAGE DURING PRE ACCIDENT INITIATED SPlKE 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 evenly 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.

3 RCS Volume: V=12062 ft (design input 1) 3 RCS specific volume v=0.02258 ft /lbm (design input 3) 4g]= x 454I 9 Equation 2.a ft 3 [lbm,

~

ib55 12062 ft 3 3

• 454IE 0.022L8 ft [lbm'

,1bm,

= 2.42E8 (g)

b. The RCS activity needs to be calculated for 60 Cl/g. UFSAR Table 11.12 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 isotopes activity by its dose conversion factor, summing the values for each nuclide arid 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 Ci/g, 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 Ci/g. To obtain the total activity at 60 Cilg, each isotope activity is multiplied by 60.

l

I REVISION NO.

1 l i

• + Exhibit E NEP 12-02 Revision 4

, COMMONWEALTH EDISON COMPANY I CALCULATION NO. : ATD 0410 PROJECT NO. PAGE NO.12 l A,{Cl} = C, b. = M{g) Equation 2 b.1 0

' Equation 2b2 D,[ rem] = A,(Ci}x DCF, l

DE t131[Cl] = . .= ' ". = 937.8 (Cij DCFnu 1.48E6 Isotope Fraction at 1 b =

^

Equation 2b.3 RCS Activityat 1 (Cl) = Equation 2h3 x dg} = 1 1 Equation 2h4 RCS Activityat 60 b = Equation 2h4(Ci}x 60 Equation 2b 5 9

TABLE 2.b Nuclide - -RC8 RCS. - ICRP-2 Total lootope; RCS--__ . RC8 Concent. - : ActMty, Dose _ . Dose, Di Fraction ActMty at Activity at C. .- As Conversion . (Eq, . at ~ 1 pCilg . 60 pCilg (UFSAR ,(Eq. Factor DCF 2.b.2). 1 pCilg (Eq. 2.b.4) (Eq. 2.b.5)

-. Table L L2.b.1) [ rem /Ci] . - [ rom] - (Eq.

11,1 2)' . [Ci] i (Ref, it)- 2.b.3)

__ [C4/g] -

l131 2.5E-6 605 1.*BE6 8.95E8 0.645 156.1 9.37E3 1132 2.8E 6 678 5.35E4 3.60E7 0.723 175.0 1.05E4 1133 4.0E-6 968 4.00E5 3.87E8 1.032 249.8 1.50E4 1134 6.0E 7 145 2.50E4 3.63E6 0.155 37.5 2.25E3 1135 2.2E-6 532 1.24E5 - 6.60E7 0.567 137.2 8.23E3 ID 1.39E9 I REVISION NO.: 1 l

.. Exhibit E NEP 12 02 Revision 4 COMMONWEALTH EDISON COMPANY

- l CALCULATIOf: NO. : ATD 0410 PROJECT NO. PAGE NO.13 I

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

4 dC(t) = -A C(t)- K,,C(t) di dC(t) , ,)

c. C(t) o 44-4I C(t) = Coe Where : t = 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> = 7200 see A, =

I 9P*

Volume of RCS

' gal' 5 1ft 3

~ 1[ min] '

12b2 fk3 ,7.48[ gal], . 60[sec].

= 1.85E - 7 sec-'

d. Since the isotope concentration is assumed to remain evenly distributed throughout the RCS volume, then the rate at which the isotope concentration leaks from the RCS, R(t), is simply the RCS leakrate times the concentration.

The total activity released dur'ng a given time interval is 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) = A, = C(t)

R(t) = A,

• Co e #4'b '

t t jR(t)dt = f A.Coe 4%'bIdt o o

=

" ' f- ()., + ).,)eN *N I dt

- (Ad +1w)o R = (A, + A )h - e-"%'b ') Equation 2.d l REVISION NO.: 1 l 1

1 1

s "

. Enhibit E NEP.12 02 Revision 4 COMMONWEALTH EDISON COMPANY 4

I CALCULATION NO. : ATD-0410 PROJECT NO. PAGE NO.14 l TABLE 2.d

_RCS Activity at 60 lootope Decay - , ,g Nuclide., ' pCWo. C. .

constene,4 (R*rence 4) (sect gg , ,,,j

- (Table 3.b) tcQ : g 1131 9.37E3 9.97E 7 1.24E1 1132 1.0$E4 8.37E 5 1.0$E1 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 Calculate the thyroid inhalation dose at the Exclusion Area Boundary (EAB) using the equation from UFSAR 15.A.4.

Table 2.e ICRP 30 Dose.

ActMty  : Conversion Factor -  : Eirclusion Area -

Nuclide Released, R4 DCP.,(Reference 17) ~

Boundary, R4 x DCF (Table 2.d)_ (CQ (rem /CQ trom]

l131 _

1.24E1 1.08E6 1.34E7 l132 1.0$E1 ,

6.44E3 6.76E4 l133 1.93E1 1.50E5 3.4766 l134 1.50E0 1.07E3 1.60E3 1135 9.88E0 3.13E4 3.09E5 Total (ERea DCF.)us 1.72E7 l

The total DE l 131 activity released is the total dose from Table 2.e divided by the 1131 dose conversion factor. Numerically this is 15.9 CI(1.72E7 rem /1.08E6 rem /ci).

lixelusion Area Boundary Dose for a 1 aom Leakrate rp Dusl rem]= -

=B= (Ri x DCF,)ca Equation 2 e.1 Aua

• 3 *

= 5.7E - 4 = 3 47E - 4 = 1.72E7{ rem]

= 3.40 (rem}

l REVISION NO.: 1 l

• '*- Eshibit E NEP.12 02 Revision 4 COMMONWEALTH EDISON COMPANY l CALCULATION NO. : ATD-0410 PROJECT NO. PAGE NO.15 l

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

• equation from UFSAR 15.A.4. The activity released during the accident from 2 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> was obtained from UFSAR Table 15.14a. This activity includes tne dose contribution from a 12.6 gpm leak in the faulted SG.

TABLE,2.f.1 _

ICRP80 Does RCS W AM Converelon Factc?, ' 240 Hour Doce, NN DCFu (Noterence #) Ai u DCFe,(rem]

A6]6 [ rom /Cl]-

I131 2.4E3 1.08E6  ! 2.59E9

~

l132 5.1E1 6.44E3 3.28E5 l133 2.3E3 1.80E5 4.14E8 l134 5.1E0 1.07E3 5.46E3 1135 5.0E2 3.13E4 1.57E7 Total (IA x DCF) 3.02E9 The total 2-40 hout dose calculated above in Table 1.f.1 is separated into specific time periods of 2 8 hrs,6 24 hrs,24 40 hrs. This is based on scaling the total 2-40 hour dose by the fraction of steam released during the same time period. The 2 40 hour4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> steam release was obtained from UFSAR Table 15.13.

TABLE 2.f.2 Steam Release, Fraction of Total Total 2 40 Hr - Fraction of Time Perkd (UFSAR Table = Steam Release Dose (Tatdo - Total 240 Hr 15.13) [lb) for Time Period _ 2 f.1) [ rem 1._ Dese[reml_

2 8 hr 939,604 0.30 3.02E9 9.06E8 _

8 24 hr 1,234,515 0.39 3.02E9 1.18E9 24 40 hr 980.806 0.31 3.02E9 9.36E8 Total Steam- 3,154,925 gg .

The atmospheric dilution factors (X/Q) for 0-8 hrs,8 24 hrs, and 24 40 hrs values were obtained from UFSAR Table 15.013. The breathing rates for 0-8 hrs,6 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 15.A.4.

X' = B = E A = DCF Equation 2.f.1 DLPz[ rem) = -

4 OsLPZ l REVISION NO.: 1 l

Ethibit E

' NEPol2002 Revision 4 COMMONWEALTH EDISON COMPANY .

l CALCULATION NO. : ATD 0410 PROJECT NO. PAGE NO.16 l TABLE 2.f.3 Atmos. Fracthmal LPZ i

. Dis,sersion Breathing Rate,' Dose, Dwa, w/

F Does' Time Factor. X/Q,- B. (UFSAR ' 1I'8 8P" Pettodi - (UFBAR Table -

WDCF'IM Lookaste 1s.o tar Tatdo 14A 1)-

. (m'/s e) 8 W l'*"I . (sque 6en 2.f.1) -  !

leersm'1 . Dom]

. 0 2 hr 1.70E 5 3.47E 4 1.72E7' O.10 ,

2 8 hr 1.70E 5 54754 9.06E8 5.34  !

8 24 2.4E 6 1.75E 4 1.18E9 0.50 24 40 1.1E 6 2.3E 4 9.36E8 0.24

. Total LPZ Does

• From Table 2.e wt 12.8 g p m ' 6.18

._Leakretepun];

3. C ALCULATION OF DOSE DUE TO PRIMARY TO SECONDARY LEAKAGE DURING ACCIDENT INITIATED SPIKE The accident initiated spike modelis the same as the pre accident model except an I additionallodine appearance rate term is added for fuel release rate into the RCS. Iri accordance with the Standard Review Plan. the reactor trip and/or primary system dentematization associated with the MSLB creates an iodine spike in the primary system.

T he spiking model assumes that the lodine release rate from the fuel rods to the primary coolant increases to a value 500 times greater than the Technical Specification limit.

This f actor adds an additional release rate factor for iodine activity,6

a. Calculate the total removal rate of iodine, h, through letdown purification and radioactive decay. Equation 2 of Reference 18 defines this total as:

A, see d

=Ao t see d +A, sec" Equation 3.a 1 0'

F, g , 3 Where : Ao t

sec" = -i 1- Equation 3.a 2 l REVISION NO.: 1 l

o '

• - . Eshibit E NEP.12 02 Revision 4 COMMONWEALTH EDISON COMPANY l CALCULATION NO. : ATD 0410 PROJECT NO. PAGE,NO.17 l The 75 gpm letdown pt.rificat:on flow F,, is converted from gpva to Orams/sec at letdown operating parameters (Design input 2 and 3 above).

~

_g gaf 1M 1m D g' i min '

p' , ,

sec, = 75, min, 7.48 gal ,

,0.01608 fta ,

Ib , ,60 sec,

= 4718 Substituting the values of F,, M and DF int o Equation 3.a.2 gives :

4718 E -..

4o sec" =- d

= 1.75E - 5 see Values of )4 for each isotope are obtained from Reference 4.

TABLE 3.a Letdown Purtt. - Total kMHne Removal Constant, W I Removal Rats,4

1. Cons ko. (E n3.a.2) g,g 4 Equat on 3.a.1 1131 1.75E 5 9.97E 7 1.85E 5 l132 1.75E 5 8.17E 5 1.01E 4 1133 1.75E 5 9.2SE 6 2.67E 5 l134 1.75E 5 2.20E 4 2.38E 4 1135 1.75E 5 2.91E 5 4.66E 5

b. The fuel release rate,)w, is defined as the product of the RCS activity and the total lodine removal rate for each isotope:

).w (Ci/sec) = A (Ci] x )4 (sec"] Equation 3.b l REVISION NO.: 1 l

'. . Exhibit E NEP-12 02 Revision 4 CMMONWEALTH EDISON COMPANY l CALCULATION NO. ; ATD 0410 PROJECT NO. PAGE NO.18 l Each fuel release rate is multiplied by 500 (Design input 5) to obtain the spiktd release tale.

T1ble 3.b ~

Total kHHne - Fuel Release Spiked ym Memovat Rete,4 male, A w (Equeuen 3,b)

R0 lease Rate See x A,w (Table s.a) leeci (cueecj gevoec]-

l131 1.85E 5 2.89E 3 1.45 1132 1.0 t E 4 1.77E 2 8.85 1133 2.67E 5 6 67E 3 3.34 1134 2.38E 4 8.92E 3 4.46 1135 4.66E 5 8.39E 3 3 20 __

c- Based on the data from Table 3.a and Table 3 b, it can be concluded that the fuel release rate is much larger than the effects of radioactive decay or leak rate removal, so Ao and A, are not considered in calculating the initial concentration of lodine in the RCS.

= -A C(t)- A.C(t) + A,s C I j dC(t) = j Avsdt c, o C(t) = C, 4 A,st Equation 3.c

d. Since thc isotope concentration, C(t) is assumed to remain evenly distnbuted throughout the RCS volume, then the rate at which the isotope concentration leaks from the RCS, R(t), is the RCS leak rate multiplied by the concentration

, determined by Equation 3.c. The total activity released during the event is calculated by integrating the release rate over the time interval.

R(t) = A.C(t)

= A,(C + Aest) fR(t)dt = f A (C, + A,st).it o o R = A, C,t+b'd' Equr.o13 d 2 ,

s

~

I REVISION NO.: 1 _

I

0 *' '

Eshibit E

, NEP 12 02 Revision 4 COMMONWEALTH EDISON COMPANY l CALCULATION NO. : ATD-0410 PROJECT NO. PAGE NO.19 l TABLE 3.d

,,,, . ay,gga . R.- R e (taw 3.M WM ;

A , Re o.se .

(S W 3.@ R (Table f.tp) [CG I131 156.1 1.45 7.16

~

1132 175.0 8.85 4.27E1 1133 249 8 3 34 1.63E1 1134 37.5 4.46 2.14E1 1135 137.2 3.20 1.55E1

e. Calculate the thyroid inhalation dose at tiie Exclusion Area Boundary and Low Population Zone using the equation from B/B UFSAR 15.A.4.

TABLE 3.e

~

ActMty Relosood, Rs DCF. RexDCF.

. Nudilh ' (Tabis 3.d) [CG [ronWCG ' [ rom]

I131 7.16 1.08E6 7.73E6 l132 4.27E1 6.44E3 2.75ES I133 1.63E1 1.80E5 2.93E6 1134 2.14E1 1.07E3 2.29E4 1135 1.55E1 3.13E4 4.85ES T.R.aDCF 1.14E7 The total DE l.131 activity released is the total dose from Table 3.e divided by the 1131 dose conversion factor. Numerically this is 10.6 CI (1.14E7 rem /1.08E6 rem /ci).

4 Exclusion Area Boundary Dose for a 1 com Leaktate:

<y R,xDCF, Equation 3 e i Ogg(reml= =Bx Acu

= 5.7E - 4 x 3.47E - 4 x 1.14E7(rem}

.m, sec

= 2.25 (rem]

l

[F<EVISION NO.: 1 t

. - . _ _. - ._- _. .-= . -. _ - ~ - - - . - - __ - - . _ _ _ -

Exhibit E NEP.12 02 Revision 4 COMMONWEALTH EDISON COMPANY I CALCULATION NO. : ATD-0410 PROJECT NO. PAGE NO. 20 ]

f. Calculate the thyroid inhalation dose at the Low Population Zone (LPZ) using the equation from UFSAR 15.A.4. The activity released during the accident from 2 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> was obtained from UFSAR Table 15.14a. This activity includes the dose contribution from a 12.8 gpm leak in the faulted SG.

TABLE 3.f.1 BCRP30,Does NOI ' -

Conversion Factor, 240 Hour Bose, '

" I Asx DCF4,(rom] -

b'y , DCFw (Reference 17)

[rwn/Ci]

l131 2.7E3 1.08E6 2.92E9 l132 1.4E3 6.44E3 9.02E6 l133 3.8E3 1.80E5 6.84E8 1134 1.8E2 1.07E3 1.93E5 1135 1.6E3 3.13E4 5.01E7 Total (IA, x DCF,) 3.66E9 The total 2 40 hour4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> dose 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 /> dose by the fraction of steam released during the same time period.

The 2 40 hour4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> steam release was obtained from UFSAR Table 15.13.

TABLE 3.f.2

. Steam Release, . Fraction of Total Total 2 40 Hr  : Fraction of -

Time Period (UPSAR Talde ' Steam Release Does (Table L  : Total 240 Hr 15.141,jtg for Time Ferlod 3.f.1) [ rem] Does trem] -

2 S hr 939,604 0.30 3.66E9 1.10E9 8 24 hr 1.234,515 0.39 3.66E9 1.43E9 24 40 hr 980.806 0.31 3.66E9 1.13E9

"" 3,154,925 Release The atmospheric dilution factors (X/Q) for 0-8 hrs,6 24 hrs, and 24 40 hrs values were obtained from UFSAR Table 15.013. 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 15.A.4. i l REVISION NO.: 1 J

Exhibit E

• NEP.I2 02 Revision 4 COMMONWEALTH EDISON COMPANY l CALCULATION NO. : ATD 0410 PROJECT NO. PAGE NO. 21 l

,e Dopz(rem) = L =B=EA=DCF Equation 3.f.1 (Qupz TABLE 3.f.3 A***

• Fractional LPZ Disprsion Breathing Rate, Dose Dm,w/ a Fractional Dose.

IAxDCF, (Table 12.8 gpm Leakrate P (UFS T .

.T SA 1) '

15.0-18 . M*/sec]

I'I'II I"3 - ' IE9"EI'" I'I'II ~

g cf,f' . Mm]

0 2 hr 1.7E 5 3.47E 4 1.14E7* 0.07 2 8 hr 1.7E 5 3.47E 4 1.10E9 8.49 8 24 2.4E-6 1.75E 4 1.43E9 0.60 24 40 1.1E 6 2.3E-4 1.13E9 0.29 Total LPZ Dose

• From Table 3.e w/ a 12.8 7.45 Leakrate [ rom]-

4. CALCULATION OF SITE ALLOWABLE LEAKRATE

a. Results of the Pre Accident Initiated lodine Spike Model The thyroid dose due to the release of activity in the secondary side of all four steam generators is 1.14 rem. The dose due to 1 gpm primary to secondary leakage in 4 steam generators with a concentration of 60 Cl/g is 3.40 rem.

Given that the dose limi :) the Standard Review Plan is 300 rem for the pre-accident model, the maximum allowable leak rate without exceeding 300 rem is:

e ,

*~

Allowable Leak Rate =

rem 3.40 s

gpm ,

= 87.90 gpm Consequently, the total EAB tiose due to a 87.90 gpm leak during a MSLB is 300 rem. The total LPZ dose calculated in Table 2.f 3 is 6.18 rem. Therefore. the EAB dose is more limiting.

l REVISION NO.: 1 l

.,I.. Eshibit E NEP 12 02 '

Revision 4 COMMONWEALTH EDISON COMPANY l CALCULATION NO. : ATO 0410 PROJECT NO. PAGE NO. 22 l Allowing 0.1 Cpm per each of the three intact steam generators leaves 87.60 gpm (87.9 0.3) for the faulted loop Note that the 87.90 gpm allowable leaktate is calculated at RCS operating conditions. Should the allowable leakrate be desired to be expressed at room temperature conditions, the 87.90 gpm must be divided by 1.406 (Ref erence 19) to account for RCS density differences. Therefore, the room temperature allowable leak rate is 62.52 gpm.

b. Results of the Accident initiated lodine Spike Model The thyroid dose due to the release of activity in the secondary side of all four steam generators is 1.14 rem. The dose due to 1 gpm primary to secondary leakage in 4 steem generators with a concentration of 1 pCilg is 2.25 rem. 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:

1 m Allowable Leak Rate =

2.25 *

s gpm ,

= 12.83 gpm Consequently, the total EAB dose due to a 12.83 gpm leak during a MSLB is 30 rem. The total LPZ dose calculated in Table 3.f.3 is 7.45 rem. Therefore, the EAB dose is more limiting.

Allowing 0.1 gpm per each of the three intact steam generators leaves 12.53 gpm (12.83-0.3) for the faulted loop.

Note that the 12.83 gpm allowable leskrate is calculated at RCS operating conditions. Should the allowable leakrate is desired to be expressed at room temperature conditions, the 12.83 gpm must be divided by 1.406 (Reference 19) to account for RCS density differences. Therefore, the room temperature allowable leak rate is 9.13 gpm.

T 1 REVISION NO.: 1 l

• ~ '

Ethihlt E NEP 12-02 Revision 4

. COMMONWEALTH EDISON COMPANY l CALCULATION NO. : ATD.0410 PROJECT NO. PAGE NO. 23 l

SUMMARY

AND CONCLUSIONS 11 is concluded from Sectio 7 4 that the accident initiated spike is more limiting, therefore the maximum site allowable SG leaktate during a postulated MSLB is 11.8 gpm at RCS operating conditions (9.1 gpm at room temperature) with a RCS DE l.131 concentration of 1 Cilg. This value includes the 0.1 gpm contribution from each of the three intact SGs.

. FINAL .

L l REVISION NO.: 1 l