ML20198L818
| ML20198L818 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 12/10/1997 |
| From: | Christiana D COMMONWEALTH EDISON CO. |
| To: | |
| Shared Package | |
| ML20198L802 | List: |
| References | |
| 95-011, 95-011-R05, 95-11, 95-11-R5, NEP-12-02, NEP-12-2, NUDOCS 9801160129 | |
| Download: ML20198L818 (11) | |
Text
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Braidwood Calculation No.95-011
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Control Room Thyroid Dose from a Main Steam Line Break Revisioit 5 12/10/97 1
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L 9801160129 900114 PDR ADOCK 05000456-Y PDR K:sgrp\\mfs\\ iodine 2. doc -.
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Exhibit C NEP 12-02 Revision 5 CALCULATION TITLE PAGE Page No.1 Calculation No:
05-011 Project No.:
N/A Ed Description Code: _R02 j
Discipline Code:
M Braidwood STATION UNIT (S) 1&2 System Code:
vc MS TITLE:
Control Room Thyroid Dese from a Main Steam Line Break Event X.
Safety Related Augmented Quality Non Safety Related REFERENCE NUMBERS Type Number Type Number COMPONENT EPN:
DOCUMENT NUMBERS:
EPN Compt Type Doe Tspe/Sub Tur Document Number
- 1. Calc / Eng DRW 97-0798-M Rev/4 2.
- 3. UFSAR Tables 15.6-9, 6.4 1 and figurc 7.2-1 (Sht. 8)
- 4. TID USAEC Tf D-14844 5 Calc / Eng _
BR-VC-02, Rev/2 6 Correspondent Westinghouse letter CAE 97-171 REMARKS:
RE\\1 SING APPRO\\TD ORGANIMTION PRIjT/ SIGN,,
DATE REY. NO.
f 5
Braidwood SEC Dan Christiana
[f, ((~
/ b i o
- ) 7
=
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Exhibit C NEP-12-02 Revision 5 i
CALCULATION TITLE PAGE Page No.1.1 Calculation No:
95-011 Ed Project No.:
N/A Description Code: _R02 Discipline Code:
M Braidwood STATION UNIT (S) 1&2 System Code:
VC.Ms TITLE:
Control Room Thyroid Dose from a Main Steam Line Break Event 4
X Safety Rdated Augmented Quality Non-Safety Related REFERENCE NUMBERS Type Number Typ6 Number COMPONENT EPN:
DOCUMENT NUMBERS:
EPN Compt Type Doc Tvoc/Sub Tvoe Document Number
- 1. Calc / Eng BRW-97-0798-M Rev/3 2.
- 3. UFSAR Tables 15.6-9,6.4-1 and figure 7.2-1 (Sht. 8)
6 Correspondent Westinghouse letter CAE 97171 REMARKS:
REVISING APPROVED ORGAN N ION REY. NO.
PRINT / SIGN DATE 0
Braidwood SEC Bruce Acas (see original for signature) 3/01/95 1
Braidwood SEC Bruce Acas (jee origuial for r,ignature) 3/17/95 2
Braidwood SEC Bruce Acas (see original for signature) 4/13/97 3
Braidwood SEC Jeff Bergner (see original for signature) 8/29/97 4
Braideod SEC Dan Christiana (see original for signature) 9/30/97
DEC 10 '97 10:42 FR C0 RED SEC DRWD 815 458 3595 TO 16306637188 P.02/02 Exhibit C NEP-12-02 Revhion 5 COMMONWEALTH EDISON COMPANY CALCULATION REVISION PAGE CALCULATION NO.95-011 PROJECT NO. N/A PAGE NO.: j REVISION SUMMARIES REV: 5 REVISION
SUMMARY
- This calculation is being redsed to include the following :
'Ilds calculation is being revised to reflect changes in calculation BRW 97 0798-M, Rev. 4: De RCS DE 131 activity limit is reduced to 0.05 Ci/g, and the projected END-of Cicle 7 leak rate during a MSLB is 122.3 gput (at room temperature and pressure). Also changes are : on page 5 rename post accident iodine spike to accident initrated iodine spike and clarify the rGlease is from o to 2 hrs; on page 6 clanfy the release is from 0 to 8 hrs and the worst case combination is changed to (b+c) froin (a+c).
Electronic Calculation Data Files: None (Program Name, Venon, file same twmWdskAour/: mm)
Prepared by:
Dan K. Lee 12/08/97 Print / Sign Date y,/
Reviewed by:
Gerald P. Lahti 12/10/97 s
a Print / Sign Date Type of Review I x 1 Detalk-
[ 1 Alternate
{ } Test DO ANY ASSUMPTIONS IN TIIIS CALCULATION REQUIRE LATER VERIFICATION [ ] YES [X ] NO Tracked by-REV:
REVISION
SUMMARY
Electronic Calculation Data Files:
(Pmenra Nune, Vamon, File nanw ewsiwdaantanh ann) t Prepared by:
Print / Sign Date Reviemxi by:
Prmt/ Sign Date Type of Review I 1 Detailed
[ ] Alternate i 1 Test DO ANY ASSUMPTIONS INTHIS CALCULATION REQUIRE LA'fER VERIFICATION [ ] YES [ ] NO Tracked by:
--__--,-----a u a v
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Exhibit D NEP-12-02 Resision 5 l
COMMONWEALTII EDISON COMPANY CALCULATION REVISION PAGE CALCULATION NO.95-011 PROJECT NO. N/A PAGE NO.: 2.1 REVISION SUMMARIES l
REV:3 REVISION
SUMMARY
- This calculation is being rnised to include the following :
- 1) Update the Calculation Title
- 2) Recalculate the control room thyroid dose using the activity release data from calculatim BRW 97-0798-M, Rev. 0
- 3) include a calculation to determine the Unit I control dose based on the Unit I Cycle 7 projected end of cycle pnmary to secondary leakage and core actmty This revision supersedes all previous rnisions of this calculation Electronic Calculation Data Files: None (Program Name, Vernon, File name en sue date hourc mm)
Prepared by:
Dan K Les 8/29/97 PrWegn Date Reviewed by: Add P. Lahti
_8/29/97 Print /Sien Date Type of Review l
l x l Detailed i 1 Alternate l 1 Test DO ANY ASSUMPTIONS IN THIS CALCULATION REQUIRE LATER VERIFICATION [ ] YES [ X ] NO Tracked by.
REV: 4 l
l REVISION
SUMMARY
- This calculation is being resised to reflect changes in calculation BRW-97 0798-M, Rev. 3 and to l
make the control room dose comparison based on eight hour releases Electronic Calculation Data Files: None (F egram Name, Version. File narne en sue datchourt nun) i l
Prepared by:
Dan K. Lee 9/30/97 Piint/ Sign Date Reviewed by:
Gerald P Lahti 9/30/97 Print / Sign Date Type of Reviav l x 1 Detailed
[ 1 Alternate l 1 Test DO ANY ASSUMPTIONS IN THIS CALCULATION REQUIRE LATER VERIFICATION [ ] YES [ x] NO Tracked by:
I Exhibit D NEP-12-02 Revision 5 COMMONWEALTH EDISON COMPANY CALCULATION TABLE OF CONTENTS PROJECT NO. N/A CALCULATION NO 95-011 REV.NO.5 PAGE NO. 3 SECTION PAGE NO.
SUB PAGE NO.
TITLE PAGE I
1.1 I
2 2.1 REVISION
SUMMARY
TABLE OF CONTENTS 3
PURPOSE /0BJECTIVE 4
METHODOLOGY AND ACCEPTANCE CRITERIA ASSUMPTIONS 4
4 DESIGN INPUT 4
REFERENCES CALCULATIONS 5-8
SUMMARY
AND CONCLUSIONS ATTACHMENTS N/A F"
t 9
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Exhibit E
' NEP-12-02 Revision 5 COMMONWEALTH EDISON COMPANY
. l CALCULATION NO. : 95-011 PROJECT NO. N/A PAGE NO. 4
_j PURPOSE / OBJECTIVE:
The purpose of this calculation is to assess the post acc. dent radiological dose to control room occupants following a main steam line break (MSLB) accompanied by primary-to-secondary coolant leakage.
METHODOLOGY AND ACCEPTANCE CRITERIA:
The approach is to demonstrate that the consequences of the MSLB accident will be less than the design basis loss of coolant accident (LOCA) assessment and are, therefore, bounded by the assessment -
- included in the Updated Final Safety Analysis Report (UFSAR).
ASSUMPTIONS:
The control room ventilation is assumed to be in operation following the MSLB. The basis for this assumption is discussed in CALCULATIONS section.
DESIGN INPUT:
The iodine releases and the maximum acceptable steam generator leak rates are from calculation BRW-97-0798-M, Rev. 4 (Reference 1). The releases from the containment and the resulting control l
room dose are from the UFS AR (References 3 and 7).
REFERENCES:
- 1. Comed Calculatiri BRW-97-0798-M, Rev. 4, " Allowable Leakrate Calculation for Steam Generator Interim Plugging Criteria," December 10,1997.
- 2. USNRC, Standard Review Plan, NUREG-0800, Section 15.6.3, " Radiological Consequences of Steam Generator Tube I ailure (PWR),"Section II, Acceptance Criteria, Rev. 2, July 1981.
- 3. B/B UFSAR, Table 15.6-9 4 USAEC Technicalinformation Document TID-14844, Calculation of Distance Factors for Power and Test Reactor Sites, March 1952.
- 5. Sargent & Lundy Calculation BR-VC+32, Rev. 2, " Radiation Habitability for the Control Room,"
May 9,1988 6.-
B/B UFSAR, Figure 7 2-1 (Sheet 8)
- 7. B/B UFSAR, Table 6.4-1 Westinghouse Letter CAE 97-171, dated July 21,1997, pertaining to the RCS water density used in octermining Byron and Braidwood Alternate Tube Nugging Limit.
l REVISION NO.: 5 l
+M
~-
J
i.
Exhibit E EP-12-02 Revision 5 COMMONWEALTH EDISON COMPANY l CALCULATION NO. : 95-011 PROJECT NO. N/A PAGE NO. 5
!l f,
- 9. Federal Guidance Report i1," Limiting Values of RadionucJes Intake and Air Concentration and Dose Conversion Factors for Inhahtion, Submersion, and Ingestion," 1988.
CALCULATIONS:
Comparison of Releases:
In order to determine control room doses for the MSLB case from doses calculated for the LOCA case, the radionuclide releases in each case must first be identified. Since the thyroid dose is the governing limit, releases of radioactive iodines will be compared.
- MSLB Release Reference I considers three release sources:
l a.
Primary coolant with a pre-accident iodine spike
- b. Primary coolant with a accident initiated iodine spike l
Secondary coolant w th iodine concentrations at c predetermined limit c.
Reference 1, then, evaluates these to obtain a limiting primary to secondary leakrate as follows. For a one gallon per minute primary to secondary leak, and a RCS I-131 activity of 1pCi/gm we have:
~
Dose Equivalent Exclusion Area Source I-131 Release Boundary Dose (from 0 te 2 hrs)
(from 0 to 2 hrs) a 15.9 Ci 4.60 rem b
10.6 Ci 3.05 rem c
5.20 Ci 1.50 rem
. NRC acceptance criteria considers the following combinations of sources and acceptance criteria:
Source Acceptable Dose Basis, Reference 2 at EAB a+c 300 rem 10CFR100 limit b+c 30 rem 10% of10CFR100 limit l REVISION NO.: 5 l
Exhibit G EP 12-02 Resision 5 COMMONWLALTH EDISON COMPANY l CALCULATION NO. : 95-011 PROJECT NO. N/A PAGE NO. 6
!l Using this criteria, Reference I calculates a limiting primary to secondary leak rate of 9.3 gallons per minute (Scenario b+c).
For the period 2-8 hours after the accideat, the weighted activity released (ERi DCFi) due to a 9.3 gallons per minute primary to secondary leak rate can be calculated from the information from Tables 2.f.2 and 3.f.2 in Reference I as indicated below.
Source Weighted Activity Released I-13 4 Dose Conversion Dose Equivident IR; DCFi (rem)
Factor (rem /Ci) 1-131 Released (Reference 1)
(Reference 9)
(Ci) a 7.17E+8 1.08E+6 664 b
8.52E+8 1.08E+6 789 i
Using this leakrate, the iodine releases for the differwt sources, from 0 to 8 hrs, are as follows :
l Source Dose Equivalent I-131 Releas.:
(frcc. O to 8 hrs) a 9.3 x 15.9 Ci + 664 Ci = 812 Ci b
- 3 x 10.6 Ci + 789 Ci = 888 Ci i
c 5.2 Ci Under these conditions, the worst case combination of(a+c) or (b+c) is (b+c), which results in a releae.
l of 893 curies of dose equivalent I-131.
LOCA Release The releases of radioactive iodines in the design LOCA case are given in Reference 3. These may be converted to dose equivalent I-131. In order to compare fairly with the control room dose assessment (because oflong term X/Q and other parameter variations), consider only the first 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of release (where all control room habitability parameters are constant).
l REVISION NO.: 5 l
l i
l Exhibit E I
EP-12-02 Revision 5 COMMONWEALTH EDISON COMPANY l CALCULATION NO. : 95-011 PROJECT NO. N/A PAGE NO. 7 ll Release, Curies Rem per Curie 0-2 hr 2-8 Total Dose Total X hr Conversion DCF Fa:: tor (Ref 4)
I-131 214 545 759 1.48E6 1.12 E9 I-132 257 217 474 5.35E4 2.54E7 I-133 469 1060 1529 4.00E5 6.12E8 I-134 320 62 382 2.50E4 9.56E6 I-l'i5 401 684 1085 1.24E5 1.35E8 Sum 1.90E9 The total dose equivalent 1-131 release is then 1.90E9/1.48E6 or 12F ; uries. Note that these are ICRP-2 dose conversion factors rather than the ICRP-30 dose conversion factors used for the MSLB dose calculation. This is done to be consistent with the LOCA control room dose, which also uses ICRP-2 dose conversion factors.
t: valuation of Control Room Ventilation System Configuration:
The proposeu control room do.;c estimation is valid only if the control room emergency filtration system (VC system) is in operation. The VC system is assumed to be in operation for the LOCA assessment (Reference 5). A review of applicable functional diagrams (Reference 6) shows that, in the event of a low steam line pressure, the VC system is activated. This assures that the proposed dose estimation is valid.
Estimate of Control Room Dose:
Reference 7 gives the control room dose calculated for a LOCA. The total 30 day dose is 16.40 rem thyroid. This calculation is documented in Reference 5. From intermediate results included in Reference 5 (page 16), one can obtain the cumulative dose for the first 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> in tl.c LOCA case is 7.21 rem. 7his would be the rsulting dose from the 1,290 curies of dose equivalent I-131 released in 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> as noted above. A normalized dose for this period can be calculated as:
7.21 rem /1290 Ci = 5.59E-3 rem /Ci Using the above LOCA results, then, one can say that, with all things being equal, the control room dose for the MSLB is proportional to the radiciodine release and would be:
893 Ci x 5.59E-3 rem /Ci = 4.99 rem l REVISION NO.: 5 l
Exhibit B EP-12-02 Revision 5 COMMONWEALTH EDISON COMPANY l CALCULATION NO. : 95-011 PROJECT NO. N/A -
PAGE NO. 8 -
ll Since the ICRP-30 dose conversion factors are smaller than the ICRP-2 dose comersion factors, use of the normalized dose based on ICRP-2 is conservative.
Estimate of Control Dose for Braidwood Unit I Cyc!c 7 :
Per Ref. I (page 23), the Unit 1 Cycle 7 allowable leakage is 132.8 gpm (at room temperature conditions) based on the proposed reduced RCS Dose Equivalent 1-131 limit of 0.05 Ci/gm for Unit 1 Cycle 7. "Ihc 132.8 gpm is obtained by dividing the leakage rate calculated at RCS temperature and pressure conditions by 1.406 (Ref. 8) to account for RCS density differences.
Per Ref.1 (page 23), the predicted Unit 1 Cycle 7 end of cycle leakage is 122.3 gpm (at room temperature conditions). The control room dose due to Unit I cycle 7 projected leak rate of 122.3 gpm can be determined based on the ratio of unit I cycle 7 leakage to the allowable leakage as follow;
= (122.3 gpm /132.8 gpm) x 4.99 rem l
= 4.60 rem l
SUMMARY
AND CONCLUSION:
Based on the Braidwood maximum pnmary to secondary leak rate of 9.34 gpm and the pnmary coolant activity of 1.0 pCi/gm, the O to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> control room dose from a Main Steam Line Break (MSLB) event was determin'd n be 4.99 rem.
Based on the Braidwood Unit ! Cycle 7 predicted end of cycle pnmary to secondary leak rate of 122.3 gpm and the pnmary coolant activity of 0.05 pCi/gm, the 0 to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> control room dose from a MSLB evert w~as determined to be 4.60 rem.
Based on these results, it can be concluded that the 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> post-accident control room dose due to the MSLB accident is less than the 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> 7.21 rem due to the design basis LOCA.
FINAL l REVISION NO.: 5 l
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