ML041040806
| ML041040806 | |
| Person / Time | |
|---|---|
| Site: | Mcguire |
| Issue date: | 03/16/2004 |
| From: | Duke Energy Corp |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| MCC-1227.00-00-0101 | |
| Download: ML041040806 (15) | |
Text
ATTACHMENT 3 Limit on NS Leak Rate in the Annulus
MAR 18 2004 12:24 FR DUKE ENERGY 704 382 7852 TO 8B754013 P.02 Form 101.1 (R6.98J CERTIFICATION OF ENGINEERING CALCULATION Station And Unit Number McGuire Nuclear Station Unit 2 Title Of Calculation Limit on NS Leak Rate in the Annulus (PIP M04-0294)
Calculation Number MCC-1227.00-00-0101 Total Original Pages
}
Through 7
Total Supporting Documentation Attachments I
Total Microfiche Attachments 0
Total Volumes 1
Type I CalculationlAnalysis Yes 0 Noo Type I Review Frequency Microfiche Attachment List O Yes i No See Form 101.4 These engineering Calculations cover QA Condition I Items. In accordance with established procedures, the quality has been assured and I certify that the above Calculation has been Originated, Checked, or Approved as noted below; Originated By Date k az'4 Checked By Date Verification Method:
ethod I Method 2 0 Method 3 El Other 0 Approved By Date -S1 Ito I2 40 Issued To Document Management Date Received By Document Management Date Complete The Spaces Below For Documentation Of Multiple Originators Or Checkers Pages Through Originated By Date Checked By Date Verification Method:
Method 1 0 Method 2 0 Method 3 0 Other 0 Pages Through Originated By Date Checked By Date Verification Method:
Method 1 a Method 2 El Method 3 a Other 0 Pages Through Originated By Date Checked By Date Verification Method:
Method 1 0 Method 2 0 Method 3 0 Other 0
MRR 16S 2004 12:24 FR DUKE ENERGY 704 382 7852 TO 88754013 P..03 NUCLEAR ENGINEERING DIVISION ENGINEERING CALCULATION REVIEW CHECKLIST Description of Analysis This calculation provides an upper limit to the leak rate from leaks recently discovered on Containmcnt Spray (NS) System piping in the annulus surrounding the containment in Unit 2 of McGuire Nuclear Station. A reduction in the limit of the effectiveness of the Potassium Iodine (KI) program in connection with the NS piping in the McGuire Unit 2 annulus also is reported.
This work is performed in support of the operability evaluation for Process Investigation Process (PIP)
M04-1294.
Determination of QA Condition I Applicability YES NO C1 E]
0 Does this analysis justify a change in a Technical Specification/COLR limit or verify the acceptability of a current Technical Specification/COLR limit?
[]
Does this analysis justify a design or a change in the performance or design of safety-
. related structures, systems, or components?
FM Does this analysis modify orJustify the licensing basis safety analysis?
E Is this analysis intended to provide the basis for, or input to, other safety-related analyses?
If the answer to any of the above questions is yes, then this analysis is safety-related and must be classified as a QA Condition I item. As such it must satisfy the requirements of NE-103 and EDMI-101.
Form NE-103.1 Revision 9
PTPR 1E 2004 12: 24 FR DUKE ENERGY 704 382 7852 TO 838754013 P. 04 NUCLEAR ENGINEERING DIVISION ENGINEERING CALCULATION REVIEW CHECKLIST NOT TO BE COMPLETED BY REVIEWER YES APPLICABLE A description of the analysis has been entered on Form NE-103. i.
f
'The QA Condition of the calculation has been determined on Form NE-I 03.1 and entered on Form EDM-I0 1.1.
E:r 2Design methods and procedures have been referenced.
v 2Design criteria have been identified.
iCl Input data and assumptions are valid and properly documented.
[]
iAll computer programs are properly identified, documented, and executed consistently with their derivation.
I
[l.
All computer programs have been certified in accordance with NSD800 as appropriate.
i: zCalculation and analytical methodologies are consistent with approved mncthodologies and numerical results have been verified.
(3 El All hand calculations have been verified.
a]
Conclusions and results are consistent with the calculations.
The required Reactivity Management section (per NSD-304) has been included and the reviewer agrees with its contents and conclusions.
El UFSAR markups have been documented.
]
g Current revision of generic REDSAR was used.
l Revisions to generic REDSAR reference values, resulting from this calculation, have been documented and communicated appropriately.
Yes No TO BE COMPLETED BY APPROVER U
M, Is cross disciplnaryrevie (C equired?
Sl) 4-Signature f >F Original Reviewed by:
Rev. __Reviewed by:
Y:
CDRby:
Date: g/14ds CDR by:
Date:
Rev. _ Reviewed by:
Rev. _ Reviewed by:
CDR by:
Date:
Date:
CDR by; Form NO103.2 Revision 9
MAR 16 2004 12:24 FR DUKE ENERGY I
704 382 7852 TO 138754013 P..05 RADIOLOGICAL ENGINEERING SECTIoN CALCULATION IMPACT ASSESSMENT SUPPLEMENT FORM CALCULATION.IMPACT ASSESSMENT (CIA) INITIATION Station / Unit PIP No. (if applical McGuire Units,I & 2 Calculation No. MCC-1227.00-00-0101 Rev.
By woZZll Date"4 Checked By' a
Date is initiated or revised.
Page i State the authority by which the calculation i LI Modification Identification #:
X PIP Corrective Action (Cf. note.)
PIP #: M04-1294 CA#:
This work supports the operability evaluation for this PIP.
El UFSAR Change Section #:
Change Package #:
El Station Request Individual:
Division/Group:
Date:
Q Other State the principal recipient and/or downstream documents that are specifically supported by the calculation.
._(Attach Additional Sheets As Required)
Form REN.101.1 Revision O
KRAR IB 2004 12:24 FR DUKE EtNERGY 704 382 7852 TO 88754013 P. 06 RADIOLOGICAL ENGINEERING SE(I'ION CALCULATION IMPACT ASSESSMENT FORM CALCULATION IMPACT ASSESSMENT (CIA)
Station / Unix McGuire NuclearStation Calculation No. MCC-12J.00-00.-0101 Rev.
0 Pagc jj PIP No. (if applicable) fA By
- Date Checked By Date Qkf SAROS reviewed to identify calculations?
NO X
YES Identify in the blocks below, the groups consulted for an Impact Assessment of this calculation originationlrevision.
Indiv. Contacted/Date Q
CEN
[Power, I & C, Electronics, Civil, Nuclear XNGO
[QA Tech. Serices (IS),
Severc Accidcnt Analysis, Elect. Sys. & Equip., Design
& Reactor Supp., Civil Structural, Core Mech. &
TIH Analysis, Mecb. Sys. &
Equip., Nuclear Design, Safety Analysis, and Matls/Metallurgy/Piping]
Jndiv. Contacted/Date F.J. Verbos (March 16, 2004)
(J MSE
[Primary, Secondary, Balance of Plant, Mech./Rotating Equipment)
E MOD
[Mechanical Engr., Electrical Engr., Civil Engr.]
Q Training E] Local IT E3 Regulatory Compliance E
Chemistry E
Radiation Protection 0 Other Q
Other 0
Q Opcrations - OPS Support Maintenance - Tech. Support Work Control - Program. Supp.
U No Group required to be consulted Listed below are the identified documents (ex. TECHNICAL SPECIFICATION SECTIONS, UFSAR SECTIONS, DESIGN BASIS DOCUMENTS, STATION PROCEDURES, DRAWINGS, OTHER CALCULATIONS, ETC.) that may require revision as a result of the calculation origination or revision, the document owner/group and the change required (including any necessary PIP # and Corrective Actions).
DOCUMENT GROUP POTENTIAL CHANGE REOUIRED MCC-1227.00-00-0095 NGO REN No change Is required. However, the conclusion of this calculation with respect to the upper limit of the effectiveness of the Potassium Iodide program currently in place at McGuire is superceded.
(Attach Additional Sheets As Required)
Fortn REN-101.2 Revision 0
M1AR 1'8 2004 12:25 FR DUKE ENERGY 704 382 7852 TO 887540 13 P. 07 MCC-1227.OO-00-0 101 March 16, 2004 MVC1l Page I
- 1) STATEMENT OF PURPOSE Leaks have been discovered in the piping of the Containment Spray System of McGuire Nuclear Station Unit 2. The leaks are located in the annulus (the concentric space between the primary containment and reactor building). The purpose of this calculation is to determine the maximum allowable leak rate for the NS System leaks in the annulus.
This work is completed to support an operability evaluation for PIP M04-1294.
1.1) BACKGROUND The redundant Class I E Containment Spray (NS) System is an ESF System provided for protection of fission product barriers at each McGuire Nuclear Station nuclear unit following a design basis accident (DBA). It is designed to remove thermal energy from containment so that the containment pressure is not exceeded following any DBA. It is also provided to remove fission products from the containment atmosphere following any DBA. For each of these design functions, the limiting DBA is the design basis (DB)
LOCA. (Ref. 8.01)
With the redundant Class IE Emergency Core Cooling System (ECCS), the NS System operates either in the Injection Phase (aligned to the Refueling Water Storage Tank -
FWST - for its source of water) or in the Recirculation Phase (aligned to the containment sump for its source of water). ESF systems operating in Recirculation may be pumping water contaminated with radioactive fission products. As such, leaks from ESF Systems are a matter of concern. ESF leaks are postulated both in the Auxiliary Building and through system connections back to the FWST. No other leaks from ESF systems in general or from the NS System in particular are postulated in design basis analyses. (Ref.
8.02-8.04)
The reactor containment of each nuclear unit is enclosed in a secondary containment or annulus. The outer boundary of the annulus is the Reactor Building. A redundant Class IE Annulus Ventilation (VE) System is provided for the cleanup of the air in the annulus.
The design function of the annulus and VE System is to hold within the annulus and remove fission products which otherwise may escape to the environment following a DBA. The DBA for the annulus and VE System is the DB LOCA. The only source of fission products in the annulus considered in design basis analyses is entrainment with post LOCA containment leakage. (Ref. 8.02-8.05)
Recently, leaks have been discovered in the pipe segments of both redundant NS trains routed through the annulus of McGuire Nuclear Station Unit 2. From the above, it is noted that these leaks are not covered in the existing design basis analyses. Problem Investigation Process PIP M04-1294 has been written and an evaluation to determine whether the annulus of McGuire Unit 2 is operable has begun. This calculation is written to support this operability evaluation. Specifically, a limit to the leak rate will be derived so that radiation doses following a DB LOCA (Ref. 4.01-4.03) will not be exceeded..
MAR 18 2004 12:25 FR DUKE ENERGY 704 382 7852 TO 88754013 P. 08 MCC-1227.00-00-0101 March 16, 2004 MVCIII Page 2 O OA CONDITION Leaks in NS System piping have been discovered in the annulus of McGuire Unit 2. This calculation provides the limits to the total leak rate to ensure that post LOCA radiation doses remain within the acceptance criteria in the license basis of McGuire Nuclear Station. These acceptance criteria keep to a minimum the risk of a DB LOCA to the public and to control room operators.
This calculation also supports an operability evaluation for PIP M04-1294.
For these reasons, this calculation is classified QA Condition 1.
-3)DESIGN METHOD Radiological consequences of the design basis LOCA with unfiltered inleakage to the control room beyond that assumed in current design basis analysis have been analyzed (Ref. 8.04). The calculated radiological consequences include offsite radiation doses and radiation doses to the control room. The limiting ofFsite radiation dose is found to be the thyroid radiation dose to the Exclusion Area Boundary (EAB). The limiting rate of NS leakage in the annulus will be derived by an approximation of what leak rate would increase the EAB thyroid radiation dose to its acceptance criterion (300 Rem). The EAB thyroid dose will be reviewed and adjusted as necessary. The margin between it and the acceptance criteria will be identified. This is deemed to be acceptable (Assumption 7.01).
Finally, the rate of NS leakage into the annulus will be approximated by comparison to the increase in ESF leakage in the Auxiliary Building associated with EAB thyroid radiation dose just within the acceptance criterion of 300 Rem. The details are reported in Section 9.
The above referenced calculation supports a program for the administration of Potassium Iodide (KI) in the wake of control room tracer gas tests conducted for McGuire (Ref.
8.07). In particular, the limit of effectiveness for the KI program was found to be 610 cfrn. This limit of effectiveness will be reduced to ensure that the EAB thyroid radiation dose is limiting of all radiological consequences of the DB LOCA. (Assumption 7.02)
- 4) APPLICABLE CODES AND STANDARDS 4.01)
Code of Federal Regulations Volume 10, Part 100, Section 100.11 4.02) Ibid. Part 50, Appendix A, General Design Criterion 19.
4.03) USNRC, Standard Review Plan for the Review of Safety Analysis Reports of Nuclear Power Plants, NREG-0800 (Rev 2). Section 6.4.11. The NRC Staff did not use the Standard Review Plan (SRP) in their review of the original FSAR for McGuire Nuclear Station. Therefore, the SRP is not in the McGuire license basis.
However, in design basis analysis of radiological consequences of DBA's, post accident radiation doses routinely are compared to the design basis analysis. For
MAR 18 Z004 1ae:de FE DUKL ENtLRY e04 JU?- ebbL' 10 k8e b40 1J P. 09 MCC-1227.00-00-0101 March 16, 2004 WVCII Page 3 this reason, certain sections of the SRP in general and SRP 6.4.1I in particular are listed in the applicable codes and standards.
- 5) DESIGN CRITERIA 5.01) Radiation Doses to the whole body at the Exclusion Area Boundary (EAB) over the first two hours following a DBA shall not exceed 25 Rem. Thyroid radiation doses at the EAB over the first two hours following a DBA shall not exceed 300 Rem. Radiation doses to the thyroid gland at the boundary of the Low Population Zone (denoted as the LPZ) over the first 30 days following a DBA shall not exceed 300 Rem.
Thyroid radiation doses at the LPZ over the first 30 days following a DBA shall not exceed 300 Rem. (Ref. 4.01) 5.02) Radiation doses to the control room operators following any DBA shall not exceed 5 Rem to the whole body or the equivalent to any organ. Specifically, radiation doses to the control room operators shall remain within 5 Rem to the whole body, 30 Rem to the skin, and 30 Rem to the thyroid gland. (Ref. 4.02, 4.03) 6 APPLICABLE SAR DOCUMENTS 6.01) G.R. Peterson to U.S. Nuclear Regulatory Commission, "McGuire Nuclear Station Units 1 and 2 Docket Nos. 50-369 and 50-370 Re: Response to USNRC Generic Letter 03-01 'Validation of Control Room Habitability,"' February 9, 2004.
) ASSUMPTIONS 7.01) It is acceptable to approach (come infinitesimally close to) any acceptance criterion or guideline value in the design and license bases of McGuire Nuclear Station.
7.02)
Only the BAB radiation dose will be considered in deriving the limit of acceptable NS leak rate in the annulus of Unit 2. Of all offsite radiation doses, the EAB thyroid radiation dose has the smallest relative margin to its acceptance criterion.
A program for post accident administration of KI currently is in place at McGuire Nuclear Station (Ref. 8.07). The limit of effectiveness of the KI program is found to be control room inleakage rate of 610 cfm (including post accident use of the control room doors for I0 cfm). Reducing this effectiveness limit will ensure that the EAB thyroid radiation dose remains limiting.
The actual details of the recommended reduction in KI effectiveness limit are reported in Section 9.
MAR 18 2004 12:26 FR DUKE ENERGY 704 382 7852 TO 88754013 P. 10 MCC-1227.00-00-0101 March 16, 2004 MVCIH Page 4
- 8) REFERENCES 8.01)
Design Basis Specification MCS-1563.MS-00-0001 (Rev 15) NS System.
8.02)
J.M. Glenn, Dose Consequences Impact of Mark-BW Fuel Reload for Accidents Analyzed in Chapter 15 of MNS FSARI MCC-1227.00-00-0048 (Rev 4), October 10, 1994.
8.03) M.V. Costello, Radiological Consequences of a Design Basis LOCA at McGuire Nuclear Station (MNS UFSAR 15.6.5.3), MCC-1227.00-00-0094. To date, this calculation has been prepared with checking in progress.
8.04)
MYV. Costello, Calculation of Post LOCA Radiation Doses for Operability Evaluation of MNS Control Room Unfiltered Inleakate, MCC-1227.00-00-0095 (Rev 0).
8.05) Design Basis Specification MCS-1564.VE-00-0001 (Rev 11), VE System.
8.06) Problem Investigation Process (PIP) M04-1294, 8.07) PIP M03-5254. This PIP reports the results of the tracer gas tests for rate of unfiltered inleakage rate to the control room. It was determined to put into place a program for administering KI to control room operators as needed following a DBA. This PIP reports the threshold for administration of KI (20 cfin) and the current limit of effectiveness of the KI program (610 cfin). Both limits include post accident use of the control room doors (IO cfm).
8.08) USNRC, Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors, Regulatory Guide 1.183, Appendix A.
8.09) USNRC, Methods and Assumntions for Evaluating Radiological Consequences of Design Basis Accidents at Light Water Nuclear Power Reactors Regulatory Guide 1.195, Appendix A.
S CALCULATIONS The calculations reported below were actually completed with an EXCEL spreadsheet.
Given the simplicity of the method used to complete the calculations, it is judged that it is enough to report the calculations here and in a printout of the EXCEL spreadsheet (Attachment 1).
The first step is to identify the limiting McGuire DB LOCA scenario. The McGuire DB LOCA with Minimum Safeguards is selected as it leads to the largest thyroid radiation doses at the EAB (as well as the LPZ and in the control room). In addition, one NS train was declared inoperable in connection with the leaks in the annulus. This configuration
IAR b8 2004 12:26 FR DUKE ENERGY 704 382 7852 TO 88754013 P.11 MCC-1227.00-00-0101 March 16, 2004 MVCfIl Page 5 (one NS train inoperable) is bounded in radiological consequences by the DB LOCA with Minimum Safeguards.
The next step it to determine the limiting EAB thyroid radiation doses. From the work performed in support of the control room tracer gas test, the limiting EAB thyroid radiation doses are Tead to be as follows:
For ESP leakage:
85.11 Rem (Ref. 8.04 file mqcruO2).
For containment leakage: 73.93 Rem (Ref. 8.04 file mqcru0l).
Only control room radiation doses were precisely calculated in the above referenced work.
In particular, the radiation doses for post LOCA containment leakage are slightly low.
This is due to the adjustment of VE filter efficiencies to model releases from two points in the upper compartment (unit vent stack and equipment hatch) with their difference control room atmospheric dispersion factors). Offsite radiation doses are calculated with no such adjustments for VE filter efficiencies. But offsite radiation doses were not the prime concern in a calculation completed in support of control room tracer gas testing.
However, offsite and control room radiation doses have been calculated for the design basis LOCA with Alternative Source Terms (AST, Ref. 8.03). For the same scenario (DB LOCA with Minimum Safeguards), EAB radiation doses are compared with and without the VE filter adjustments as follows:
Without VE filter efficiency adjustments: 45.11 Rem (Ref. 8.03 file mlocaO7).
With VE filter efficiency adjustments:
45.06 Rem (Ref. 8.03 file mlocaOl).
The limiting EAB thyroid radiation dose is projected to eliminate the effects of VE filter efficiency adjustments as follows: (73.93) (45.11) /45.06 = 74.01 Rem.
Now the limiting EAB thyroid radiation dose is computed as follows:
Post LOCA ESF System leakage: 85.11 Rem.
Post LOCA containment leakage: 74.01 Rem.
Post LOCA EAB thyroid dose:
159.12 Remn.
Margin to 300 Rem = 300- 159.12 = 140.88 Rem.
Next, a known leak path and associated radiation dose is selected for projection to the 10 CFR 100 criterion for EAB thyroid radiation dose. The NS System is an ESF system.
Leaks from an ESF System either to the FWST -or in the Auxiliary Building are considered and post LOCA radiation doses calculated. These NS leaks are located in the annulus. Post LOCA radiation doses for releases from the annulus are based normally on containment leakage to the annulus. The above three leak paths (ESF leaks to the FWST, ESF leaks in the Auxiliary Building, and containment leakage) are available for comparison to the NS leaks in the annulus. Volatile iodine formed in the FWST and partitioned into the FWST airspace is released through displacement by the assumed ESF leakage and diurnal expansion of the tank. This is seen to be significantly different from
rIAR 18 2C rv l
- sofas go Ace-(J 104 Ie:e' Z
H
- DUKL LNELR Y
eU4 3U8 e8te TO B8754013 P.12 MCC-1227.00-00-0101 March 16, 2004 MVCIII Page 6 the release path of ESF leakage in the annulus which is transported through the VE System and released from the unit vent stack. Therefore, ESF leakage to the FWST is dropped from consideration.
This leaves ESF leakage in the Auxiliary Building and containment leakage.
The calculations of radiation doses of the DB LOCA simulate removal of fission products from containment atmosphere by the NS System. No such cleanup mechanism for containment leakage is available for NS leakage to the annulus.
No cleanup of contaminants in the containment sump or ESF System piping prior to release in the Auxiliary Building is assumed. In this sense, the NS leakage in the annulus is more similar to ESF leakage in the Auxiliary Building. The VE and VA Systems are available to remove airborne iodine from the NS leak in the annulus and ESF leaks in the Auxiliary Building, respectively. The VE System operates at times in the Recirculation Mode while the VA System always is in a Once Through alignment.
Therefore, comparing the NS leak in the annulus to ESF leaks in the Auxiliary Building is conservative. This conservatism in the calculation is acceptable.
One additional factor that should be considered in comparing the NS leaks in the annulus to ESE leaks in the Auxiliary Building is that only some of the iodine entrained in the ESF leaks in the Auxiliary Building is assumed to be airborne. The partition fraction for the first 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> is only 10% or 0.1. From conversations with the McGuire Engineering Staff, it is apparent that the NS leak areas are very small. The pressure in the NS piping in the annulus may be significantly above ambient when the NS System is in operation.
Therefore, the leak flow may be atomized. Furthermore, the leaks may be swept into the VE System ductwork. This is assumed for containment leakage pursuant to NRC Staff regulatory positions (Ref. 8.08, 8.09) and will be assumed here for the NS leakage in the annulus. For these reasons, it is assumed that all iodine entrained in the NS leakage to the annulus is swept into the VE System without partitioning.
This is equivalent to setting the iodine partition factor for the NS leakage to the annulus (fr,,,) to 1.
One final item must be taken into account and resolved. It is the thyroid radiation dose in the control room. Currently, the McGuire Control Room Area Ventilation (VC) System is Operable but degraded with the KI program put into place as a condition of operability.
The limit of effectiveness of the KI program was calculated to be a rate of control room unfiltered inleakage of 610 cfm (Ref. 8.04). The new design basis value of control room unfiltered inleakage rate is 210 cfn (Ref. 8.03). The error adjusted rate of control room unfiltered inleakage rate was found to be 177 cfm (Ref. 6.01). All of the above figures account for post accident use of the control room doors (10 cfin). From the above, it is apparent that setting the limit of effectiveness of the KI program to 210 cfrn will ensure that the EAB thyroid radiation dose is bounding.
We'now are ready to estimate the maximum allowable rate of NS leakage in the annulus.
From the above, considerations, the formula for estimating the maximum allowable NS leak rate in the annulus asersO allowed in a calculation of post LOCA radiation doses is as follows:
INSnnn = (ADEASBhymarg I DFARthyFSF) fE3F 'tSF
MAR 18 2004 12:27 FR DUKE ENERGY
,;A -
704 382 7852 TO 88754013 P. 13 MCC-1227.00-00-0101 March 16, 2004 MVCJII Page 7 where ADEAB9hymarg is the margin in EAB thyroid radiation dose to 300 Rem = 1 40.88 Rem, DEAB,jYESF is the EAB thyroid radiation dose = 85.11 Rem, fiESF is the iodine partition fraction for ESF leakage = 0.1, and IESF is the assumed ESF leak rate in the Auxiliary Building = 0.7 GPM.
In the above formula, it is understood that the iodine partition fraction for NS leakage in the annulus (fiend is set to 1.
Setting the numerical values gives 1NZSndn = (140.88 Rem / 85.11 Rem) x 0.1 x 0.7 GPM= 0.116 GPM.
Pursuant to Staff regulatory positions (Ref. 8.08, 8.09), this value is divided by 2 to give the maximum allowable rate of NS leakage in the Auxiliary Building.
,NSV.n.
0.116 GPM / 2 - 0.058 GPI = 3.5 GPH.
jM) CONCLUSIONS It is determined that the radiological consequences of a design basis LOCA remain within the germane acceptance criteria and guideline values for McGuire Nuclear Station with the rate of NS leakage in the annulus set to 0.1 16 GPM (7 GPH). Division by a factor of 2 as cited in NRC guidelines, it is recommended that the rate of NS leakage in the annulus not exceed 0.058 GPM (3.5 GPH).
The limit of effectiveness of the Potassium Iodide is reduced to 210 cfn for the duration of the operability evaluation of PIP M04-1294.
There are no Reactivity Management (NSD-304) issues associated with the problem addressed in this calculation.
1 1) ATTACHMENTS EXCEL Spreadsheet Calculation (printout only).
MAR 16 2004 12:2? FR DUKE LNERUY
?04 382 7852 TO 88754013 P.14 A
B C
D E
F G
H I
CALCULATION OF LIMITING NS LEAK RATE IN THE ANNULUS (DB LOCA RADIATION DOSE' 2 Radiological Engincering Support for Operability Evaluation for PIP M041294, 3 CALCULATION MCC-1227.00-0O-0101 Attachmentil 4
5 Radiation Doses from Operability Evaluation for Control Room Uoniltered Icakage (MCC-1227.00-00-0095) 6 The EAB thyroid radiation dose is limiting. Control room radiation doses are controlled by lowering the 7
stated limit of effectiveness ofKl program from CRU=610cfmitoQRCU=310cfm.
9 EAB thyroid radiation dose for containment leakae ernmj
=uOl)
_73.93L Rem.
10 7_
11 This calculation was performed with VE filter efficiencies increased to account for the release points and 12 control room X/fuQ's being different for upper comyartment leakage to the annulus and upper corraiment 13 byass leakage. Therefore the thyroid radiation dose has to correspond to unadjusted VE filter efficiencies.
14 An aproxiMnation is made by multiplying the EAB thyroid dose for containment Leakage by a ratio of 15 thyroid radiation doses for containmnent leakage with unadjusted VE filter efficiencies and adjusted VE 16 filter efficiencies.
T 17 1
18 From MCC-I 227.00-00-0094 (the MNS AST LOCA calculation), the followving values are taken for EAB 19 thyroid radiation doscs for containment leaka 20
~~~~~~~___
= -1.....
..,l_.
21 EAB thiyroid radiation dose for cont leak and unadjusted VE filt eff -45.1 Renm.
,(rmlocaoi) 22 EAB thyroid radiation dose for cont leak and modified VE filt eff-45.061 Remn.
(mpocaOij 23 J
i.-.-
24 Adusted EAB thyroid radiation dose for containment leakne -
i 74.01* Rem.r B_.__
.j_
25
- i.
'-t....:.
I
___... j 261:**l 27 The next sie_ is to find the allowed increase in radiation dose from accommodating the NS leakage into the 28 annulus. Thiis i
taking
.v
,I______________k__
29 D(EAB7hydose)
EABThydose (target) - EABThydose(ESFlcak) - EABThydose (cont leak) 30 31 EAB thyroid dose for ESF leakage =
I
- 85. II Rem.
(mqcruO2) 32
.L.
33 Target radiation dosebyassumption(I0CFR 100 lirnit)
L Rr 34 d
300.00_
Rem.
35 Delta Total EAB radiation dose (D(DosethyEi A 140;88l Rem.
- 36.
38 _
L....-.--..--._.1 i---
-. s 39 EAB leak rate in the Auxiliary Building =
i l
o.ioS GPM.
40 I.,
41 Additional equivalent containment leak rate to the annulus is found by taking the ratio of the 42 differential EAB thyroid radiation dose to the ESE thyroid radiation dose and applying it to the 43 ESF leak rate times the iodine partition fraction for the first 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> (the time of the EAB 44 radiation doses). The NS leak is assumed to be in the annul.us. All iodine 1
~.
45 entrained in the leakage is assumed to be educted into the YE System which filters it once then 46 either exhausts it or recirculates it. Over the first 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> 10% of the iodine in the ESE leakage in the 47 AMiliar_'Building becomes airborne. This iodine is filtered once by the VA System then released via 48 the Unit Vent Stack.
4 9, ~..............._.._____
50 The iodine partition fraction for 0-2 hr
.ne) is 0.10i O-r o
e j-
.11 I
I
MRKI-1)8 eU4 1e8i I-FH VUKt LNEtXY (04 LJUd e8nef I
U U {n4W1 P.
15 A
B I
C I
D I
E l
_F G
l H f 52 The limitingpost accident leak rate in the VA System is i
53 I
F 54 LeakESF
- fpartiodine) * (D(EABThydose)/DoseThy(ESFlcak))
i 0.116. GPM i
r_.
56 This is the postaccident leak rate. It is divided by 2 to account for leak detection and measurement under 57 conditions for normal unit operation vs potential for higher leak rate under post accident conditions..
8.
_8
___ J
.~
59 Lirniting NS leak rate in the annulus for PIP M04-1294 is I
0.058 GPM.
60 3.48 GPH i
TOTAL PAGE.15 **