ML20078P060

Auxiliary Bldg Ventilation Sys Interim Operation Plan

ML20078P060
Person / Time
Site:	Byron
Issue date:	10/27/1983
From:	COMMONWEALTH EDISON CO.
To:
Shared Package
ML20078P057	List: ML20078P054 ML20078P060 ML20078P064 ML20078P069
References
7510N, PROC-831027, NUDOCS 8311030183
Download: ML20078P060 (18)

Text

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ATTACHMENT A i

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Auxiliary Building Ventilation System Interim Operation Plan i

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October 27, 1983 7510N

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8311000183 831'027 PDR ADOCM 05000454 A PDR 4

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I.- Auxiliary Building Ventilation System The Auxiliary Building HVAC System at Byron-is a. common system for

, Unit 1 and Unit'2.which; serves various plant areas of the Auxiliary

. Building including. engineered safety features-cubicles-and the Fuel Handling Building. A complete description of this system can be found  :

1-in Secton 9.4.5.1 of the Byron /Braidwood FSAR. Current preoperational testing requirements for the system are given in Table 14.2-35 of the FSAR. These requirements call for the entire system to be complete 4

and' preoperationally tested : prior _to LUnit.1 Fuel Load.

The.two units at Byron willLnot be' completed simultaneously. Because I

, the Auxiliary Building Ventilation System is common to both units, operation ~'of the entire system is not-required to support Unit 1 '

operation. There is no need for this system to serve the Unit 2 portions of1the Auxiliary' Building while Unit 2 is under f construction. ..This system has been recently reviewed from an lL 1

operating standpoint and those portions required for Unit 1 operation have been identified. These portions of the system will become

j. operable. and will be tested at various stages of Unit 1 startup.

Details of the startup plan.for the system follow:

, A. For Unit 1 Fuel Load, components requiredEto cope with-accidental

' criticality will be maintained within design temperatures, i  : Therefore,.the following portions of the Auxiliary Building Ventilation System'will be operational prior to Unit 1-Fuel-Load:

1. Unit 1-Residual Heat Removal Pumps A&B Cubicle Coolers

- 2 .- Safety Injection Pumps lA and 18 Cubicle Coolers

3. Centrifugal Charging Pumps lA, 18, and 1C Cubicle Coolers 7

4. Essential' Service Water Pumps lA and 18 Cubicle Coolers

! 5. ' Unit 1 Auxiliary Feedwater Diesel-Driven Pump Cubicle Cooler

6. ' Unit 1 Containment Spray. Pump 1A and 1B Cubicle Coolers i B. Prior to Unit I criticality, the potential for release of l- radionuclides.is very insignificant.. Fission products will not be produced at. levels that will endanger public safety.

Therefore,^the entire Auxiliary Building Ventilation System is

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not required to be operational. However, during this period the iollowing will be completed:

1. - Unit 1:and Common'Ductwork will be installed

-2. Supply and Exhaust Fans,will be available to be run

.3., All Remaining Unitfl Cubicle Coolers will be operational

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C. Beyond initial criticality and for up to an equivalent of ten full power days of operation, not exceeding 25% of full power, the amounts of radiation released during normal operation, during a core unloading event or during a loss-of-coolant accident are within the radiological release limits. As a result, operation of Unit 1 during this period without the Auxiliary Building Ventilation System fully operational will not pose any significant hazard to public health and safety. A detailed justification for this is provided in Attachment 1. Therefore, the following will be completed prior to ten full power days of operation at 25% power or less:

1. Unit 2 Exhaust Ductwork will be blanked off and Unit I will be isolated from Unit 2.

2. The air flow through all main supply ductwork, Unit 1 and common accessible areas and nonaccessible areas exhaust ductwork and the Fuel Handling building exhaust ductwork will be balanced.

3. Accessible areas, nonaccessible areas and Fuel Handling Building exhaust filter plenums will be filter tested as follows:

3.1 Prior to the balance of airflow through the ductwork the following tests will be performed:

3.1.1 Visual Inspection 3.1.2 Housing Leak Test 3.1.3 Mounting Frame Pressure Leak Test 3.1.4 Airflow Capacity and Distribution Test I~

3.l.5 Air-Aerosol Mixing Uniformity Test i

For items 3.1.4 anu 3.1.5 artificial resistance in lieu of actual filters will be used to achieve required pressure drops.

3.2 Af ter the balance of airflow through the ductwork the following tests, will be performed. However, prior to these tests it will be verified that the airflow rates through each plenum are close to the airflow rates established in the previous tests.

3.2.1 In-Place Leak Test, HEPA Filters 3.2.2 In-Place Leak Test, Adsorbers.

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4. A special test to verify proper functioning will be performed on the Unit 1 and common portions of the system.

D._ Section 6.5.1.3 (Item h) of the Byron /Braidwood FSAR states that the Fuel Handling Building Exhaust System is_ designed to maintain the Fuel Handling Building at a negative pressure of 1/4 inch water gauge with respect to atmosphere. During the normal operation of Unit 1 prior to Unit 2 completion it will be impossible for this system to perform this function. The Fuel Handling Building is located between the Unit 1 and Unit 2 containment buildino and the equipment hatches from each containment open directly into it. During Unit 2 construction the Unit 2 hatch will remain open.

A negative pressure is required in the Fuel Handling Building to prevent airborne radioactive releases. Without spent fuel in the building such releases are impossible. Only as a result of a Unit 1 core unloading event will there be spent fuel in the Fuel Handling Building prior to Unit 2 completion. Only under these circumstances will the Fuel Handling Building be maintained at a negative pressure with respect to the atmosphere.

In summary, Byron Unit 1 can be operated for an equivalent of ten full power days at 25% power or less with the Auxiliary Building Ventilation System inoperable and not exceed radiological release limits.

Therefore, the Unit 1 and common portions of the system will not be fully operational, filter tested or funtionally tested until Unit 1 has been operated for an equivalent of ten full power. days at 25% power or less.

A negative pressure _will not be maintained in the Fuel Handling Building unless there is a Unit 1 core unloading. event. After Unit 2 completion the entire Auxiliary Building' Ventilation System including Unit 2 portions will be integrally balanced and then preoperationally tested as required.

'7510N-

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'.:l. . *. *^ k!TAOVAYENT A

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Radiological Impact of Byron's Auxiliary Building Ventilation System

. 1. Introduction 1

The. radiological impact'of the site boundary is dependent upon equipment le'akage and the' operation of the auxiliary building r exhaust' filtration system during normal and abnormal operation.

, 2. Maximum Offsite Doses During Normal Operation s ..

. A. VA System Filtration Equipment-Operational i

FSAR Table 11.3.9 (attached) give the maximum expected offsite doses to individuals due to gaseous effluent i pathways during normal full power operation of both units.

This table is based on the VA system removing 99% of the particulates, excluding halogens (iodine). No credit is

~taken for radioisotopic decay-in-transit to the locations given-in this table.

, The majoi contributors are given in Table 11.3-6. The i . major contributors include the waste gas exhaust, .the volume reduction system exhaust and the auxiliary building i ventilation exhaust. . The VA system is expected to account

! for less than 10% of the normal particulate _ release ~ (see

, Table 11.3-6). Since the waste gas and volume reduction exhausts'are operated ~ periodically, they can-be controlled to limit the offsite releases.

, -The radiological impact of liquid releases is given in L. environmental' report (ER) Table 5.2-7. -Summarizing this

! Table, we. have the following maximum dose rates: 0.84 [

mrem /yr whole body, 2.5 mrem /yr.to the thyroid, and 0.54

-mrem /yr to the.GI-Tract. The maximum radiological impact of. gaseous releases from FSAR-Table 11.3-9 are summarized as follows: 0.~36-mrem /yr whole' body (child), 0.77 mrem /yr

[ to the thyroid (infant), 0.31 mrem /yr to the liver (child) ,

and 0.28 mrem /yr to the GI-Tract (child).

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B. VA System Filtration Equipment Operating with Variable Flow fChanges in the air flow through the VA system.will not affect the maximum expected offsite dose rates. The..a.irborne curie' production due to normal statfon operation will not change; therefore, the annual gaseous releases of radio--

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- active 1sotopes will be independent of the VA exhaust rate.

The only conditions that can significantly affect the offsite. doses is when the VA System Filtration Equipment ~

are bypassed.

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Page 2 B. VA System Filtration Eauioment Ooerating with Variable Flow (Cont'd)

Table 11.3-7 gives the maximum expected isotopic concentrations at the site boundary. Converting these concentrations into fractions of the Maximum Permissible Concentration (MCP) , we have 5.77 x 10-4 MPC for two unit normal operation at full power. Bypassing the

• , particulate removal equipment will increase the MPC fraction to 5.85 x 10-4 for single unit full power opera-

, tion. Appendix I allows 1.00 x 10-2 MPC to the whole body from all releases.

The dose affects on the internal organs are much more sensitive to the release of particulates, i.e., the dose to the organs is assumed to be proportional to the particulate releases except for the thyroid. The doses to the thyroid will not change because no credit for iodine removal was used in the model for FSAR Table 11.3-9.

Table A attached gives the maximum annual dose race for the following conditions.

a. Two units full power and VA System filtration equipment in service.

b. One unit full power and VA System filtration equipment in service.

c. One unit full power and VA System filtration equipment bypassed. , , , __

.d.* One unit at 5% power and VA System filtration equipment bypassed.

3. Abnormal Offsite Doses A. VA System filtration Equipment in Service The post-LOCA control room and offsite doses associated with the ~ VA System are due to ESF leakage inside the auxiliary building. The ESF doses are based on the airborne activity from a design basis LOCA.(full power with 1000 days.of uninterupted burnup). The VA System filtration equipment is designed to remove 90% of the iodine and 99% of the' particulates that could be exhausted to the atmosphere.

In Section 15.4.1.2 of the Safety Evaluation Report (SER) states that the staffs dose calculation for a continuous filtered release of 1.0 gpm of ECCS leakage would produce '

77 rem to the thyroid at the EAB. The NRC analysis is based on the 1.0 gph ECCS leakage used in FSAR Table 15.6-16.

In Section 15.4.1.1, the staff calculated the containment exfiltration dose to the EAB as 172 rem to the thyroid.

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A. VA System Filtration Equipment In Service (Cont'd)

Based on the above values and the whole body doses, the staff  !

determined that a design basis LOCA with the VA System filtration {

equipment.in service would result in'" radiological consequences of a postulated LOCA will be within the exposure guidelines set for in l

, .the' 10CFR100.ll." (SER Section 15.4.1.3). -

l ~B.- 1/A System Filtration Equipment By-Passed i If the VA System filtration equipment is bypassed, the station's I operating condition would have to be adjusted to limit the release of iodine to the same potential levels that might be experienced i n i a design basis LOCA.. Changing the iodine removal efficiency f rom 90%-to zero percent will increase .the iodine releases in the 1

i auxiliary building by a.f actor of 10 'at full power operation.

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At a maximum of 25% of full- power operation, the iodine production rate f rom the Aux. Building at the site boundary will be increased by a f actor - of 2:. 5, wh ich is 192 rem.- The iodine production rate f rom the containment at the site boundary will be decreased by a f actor of 4, wh ich i s 43. rem. Since the most significant iodine isotopes have short half lives, their production will be proportional to the power level. Maintaining the power level below 26% of full power will result in the necessary iodine reduction. Limiting the power .

1 level-to 25% of full power will result i n thyroid doses of 235 rem  !

at the site boundary from both the auxiliary building and the

. containment, which is less than the values calculated by the NRC staff for' the design basis LOCA. ,

Operating the Unit #1. reactor at a maximum of 25% of full power for ten full power days will produce 1/100 of the long lived isotopes

[ which i nclude.Kr85 and most of the particulates. Bypassing the VA System's particulate filters will increase the particulates by a  !

factor of 100. Thus, the post-LOCA ESF doses due to particulates  !

will be ' equal ~ to the stations design basis LOCA.

' The noble gases are primarily short lived isotopes, and their production is proportional to the operating power level. By

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keeping the power level to a maximum of 25% of full power, the noble gas-production will be reduced by a factor of 4. As-a result, the whole body doses due to a LOCA operation at 25%: power would be reduced by (almost) a f actor of 4 because about 99%~of the whole body dose is due to noble gases.

The~ above can be applied to the EAB, the LPZ, and the control room, because the do'ses are proportional to the post-LOCA releases. -

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' ' 4. Conclusion .

'! Byron Unit #1 can be safely operated at power levels that do not exceed 25% of full power for ten full power days while the VA filtration. equipment is not i n service. Th e radiological consequences of iodine and noble gases for a LOCA following ten

' full power days operation at 25% of full power can be maintained to

.. a level that i s within' the design basis LOCA described in SER

.. Section 15.4 while the VA System is not fully operational, i.e.,-

the charcoal filtration equipment is bypassed.

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TABLE A  %

s Full' Power Offsite Doses for Normal Operation k

Station (mrem / year)

Operation Particulate Whole Thyroid Pathway Filtration Internal Body Dose Dose Organ Dose 3 i two units, liquid No full power 0.84 2.50 0.54 N waste gas No VA System 0.35 0.74 0.30 Yes 0.014 0.03

. 0.012 1.21 .3.27 0.84~

one unit, liquid No full power 0.42 1.25 0.27 waste gas No 0.18 (conservative VA System Yes 0.020 0.37 0.15 VA filtration)* 0.02 0.10 0.62E 1.64 0.52 one unit, liquid No full power 0.42 1.25 0.27 waste gas No 0.18 no VA VA System No 0.37 0.15 filtration

• 0.02 0.02 10.00

, ,_ 0.62 1.64 10.42 one. unit, s liquid No 0.02 0.06 <0.02 5% power waste gas No 0.01 no VA 0.02 <0.01 VA System No <0.01 <0.01 filtration 0.50

<0.04 <0.09 <0.53 t '

Appendix I Requirements 5.00 15.00 15.00

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• The particulate releases in FSAR Table 11.3-9 are dominated by the waste gas system exhaust, approximately 90%. The conservative VA filtration.model assumes that the waste gas exhaust only contributes 60% of the particulates.

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. TABLE 5.2-7

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PATHWAYS DOSES PROM LIQUID'EFFLU'ENTS BODY SKIN THYROID BONE PATHWAY (mrem /yr) (mrem /yr) _( mrem /yr) GI-TRACT" (mrem /yr) (mrem /yr)

Consumption of Fish 2.71 x 10

-1 -

6.83 x 10 -2 2.08 x 10-1 1.15 x'10-2 k S,horeline o -3 Activities 4.70 x 10 5.49 x 10 -3 4.70 x 10 -3 4.70 x 10 -3

, 4.70 x 10 -3 as Swimming and ,

E' ta Boating 1.53 x 10-4 1.98 x 10-4 ~~ l'.53 x 10-4 ,1.53 x 10-4 s.

1.53 x 10-4 L Dri6 king Water b 5.59 x 10

-1 0 -2 o

2.39 x 10 4.23 x 10 5.15 x 10 -1 Appendix I , -

M 10 CPR 50 T Design Objectives 0 1 1 O 3.0 x 10 1.0 x 10 -

1.0 x 10 1 1 1.0 x 10 1.0 x 10 E 1 Note: All activities are assumed to take place in the discharge canal. No credit

' is taken for dilution of effluents in the Kankakee River. Values based on l-unit operation.

a

Gastro-Intestinal Tract. .

b The nearest municipal water intake is 121 miles downstream at Peoria, Illinois, on the Illinois River. Diluting the radwaste discharge flow (46.8 cfs) in the annual avera e Illinois River flow (10,680 cfs) produces a dose reduction factor of 228. The expc. ed thyroid dose,at this location becomes 0.010 mrem /yr. ,

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TABLE 11.3-6 (Cont'd) '

AIRBORNE PARTICULATE RELEASE RATE - CURIES PER YEAR * .

WASTE GAS BUILDING VENTILATION NUCLIDE ' SYSTEM REACTOR AUXILIARY TOTAL .

bei 54 4.5 6.1-06 1.8-04 4.7-03 FE 59 CO 58 1.5-03

^ 1.5-02

'2.1-06 2.1-05

. 6.0-05 1.6-03 k 6.0-04 1.6-02 CO 60 ,

7.0-03 9.5-06 2.7-04 7.3-03 SR 89 3.3-04 4.7-07 1.3-05 3.4-04 l

SR 90 ;. 6.0-05 8.4-08 ,2.4-06 6.2-05 CS134 4.5-03 6.1-06 1.8-04 , 4.7-03 CS137 7.5-03 1.1-05 3.0-04 7.8-03 I I y ,

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• In addition to, these releases, 25 C1/yr of argon-41 are released from the containment and 8 C1/yr of carbon-14 aro'rolcased from the wasto gas processing system. This table was dovoloped taking into f

account both releasca from normal operations and also oporational occurrencos. k XEY: 4.5-03 = 4.5 x 10~3 ,

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E B/B-FSRR TABLE 11.3-6 (Cont ' d) .

VOLUME REDUCTION SYSTEM RELEASE RATE (Ci/yr)

Noble Gases:

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Xe 131m 5.1-01 Xe 133m 1.2+00 Xe 133 2.1+01 .

Halogens: *

I 131 2.8-03 -

I 132 3.7-03 I 133 2.1-03 Tritium:

H3 2.6+01 ,

Particulates:

Cr 51 5.3-08 Fe 55 7.0-07 Co 58 6.0-07 ~

Co 60 9.2-08 Ni 63 7.0-07 Y 91 1.5-09 Mo 99 3.5-07 p& Tc 99m 2.1-09 Te 132 1.5-07 Cs 134 1.1-05 '

Cs 136 1.9-07 -

, Cs 137 7.4-07 KEY: 5.1-01 = 5.1x10 -1 g

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b~5 BYRON-FSAR AMENDMENT 34 NOVEMBER 1981 TABLE 11.3-7 COMPARISON OF MAXIMUM OFFSITE AIRBORNE CONCENTRATIONS WITH 10 CFR 20 LIMITS MAXIMUM SITE

' ANNUAL RELEASE BOUNDARY

• 10 CFR 20 FROM ONE UNIT CONCENTRATION CONCENTRATION

..- ISOTOPE (Ci/yr) (uCi/ml) _( uCi/ml)

.H 3 1.0+03 3.5-11 2.0-07 f.8 - 4 C 14 8.0+00 2.8-13 1.0-07 2,0 - G Ar 41 2.5+01 8.8-13 4.0-08 2. 0 -5 Kr 85m 5.0+00 1.8-13 1.0-07 15-6 Kr 85 7.0+02 2.5-11 3.0-07 S'3-5 Kr 87 1.0+00 3.5-14 2.0-08 la3

Kr 88 8.0+00 2.8-13 2.0-08 li 4 - 5 Xe 131m 4.0+01 1.4-12 4.0-07 3. 5 -4 Xe 133m 1.6+01 5.6-13 3.0-07 f. 9 -6 Xe 133 2.0+03 7.0-11 3.0-07 23-9 Xe 135 1.5+01 5.3-13 1.0-07 73-6 Xe 138 1.0+00 3.5-14 . 3.0-08 3'1

m ' I 131 5.4-02 1.9-15 1.0-10 I' 7 ~ 5

~ I 132 3.7-03 1.3-16 3.0-09 4'3 - 9 I 133 7.2-02 2.5-15 4.0-10 C.3 - 6

. Cr 51 5.3-08 1.9-21 8.0-08 I4+

Mn 54 4.7-03 1.7-16 1.0-09 la -7 Fe 55 7.0-07 2.5-20 3.0-08 3.3 -17 Fe 59 1.6-03 5.6-17 2.0-09 LS-8 Co 58 1.6-02 5.6-16 2.0-09 2. S 7 Co 60 7.3-03 2.6-16 3.0-10 B ' 7 Ni 63 7.0-07 2.5-20 2.0-09 h 3 -l' Sr 89 3.4-04 1.2-17 3.0-10 9 - 8 Sr 90 6.2-05 2.2-18 3.0-11 7'3 - 8 Y 91 1.5-09 5.3-23 1.0-09 I' 3 - 'd Mo 99 3'.5-07 1.2-20 7.0-09 I' ' ' ' 1 Tc 99m 2.1-09 7.4-23 5.0-07 I

Te 132 1.5-07 5.3-21 4.0-09 l'3 ' '2 Cs 13.4 4.7-03 1.7-16 -4.0-10 '

"'I ' I Cs 136 1.9-07 6.7-21 6.0-09 .

l'"' ' #t 5.0-10 ' _ "

Cs 137 7.8-03 2.7-16*

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• 0.26 mi E X/Q = 1.11 x 10 sec/m .

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TABLE 11.3-9

• BYRON-EXPECTED INDIVIDUAL DOSES FROM GASEOUS' EFFLUENTS M t\

DOSE RATE (mrem /XP)

TOTAL LOCATION PATHWAY BODY SKIN THYROID BONE LIVER LUNG GI-LLI Nearest Residence Plume 0.023 0.073 (0.3 mi,ESE) '

Ground Deposi ~

• b4 tion .

0.057 0.067 Inhalation -

. Adult 0.030 0.048 0.004. 0.030 Teen 0.031 0.032 0.030 -

Child

. 0.053 0.005- 0.031 0.033 0.031 0.027 0.054 0.007 0.028 0.029 infant 0.027 0.016 0.040 -

0.005 0.016 0.017

' 0.016 W

Nearest Gaiden Leafy Vegetables' (0.6 mi SW)

N Adult 0.006 , 0.028 0.002 0.006 0.006 0.006 0-Teen 0.004 0.023 0.002 0.004 0.004' O.004 Child 0.005 0.033 0.004 4 0.005 0.005 0.005 g

. . ' Stored Vegetables x

. Adult 0.083 0.081 0.033 0.084 0.079 Teen 0.081 0.103 0.102 0.057 0.108 0.100 0.101 0.169 s Child -

0.171 0.138 0.167 0.180 0.167 O

Nearest Meat Meat '

Animal Adult O.019 O.023 0.016 0.019 0.019 0.019

. (0.6 mi SSE) Teen 0.013 0.016 0.014 0.013 0.013 0.013 Child 0.017 0.021' O.025 0.017 0.016 4

0.016 Nearest Milk Cow '

iMilk

• gg S .

(1. 5 mi NE) Adult < cu 0.027 0.102 0.025 98 g 0.012 0.027 0.025 Teen 0.037 0.164 0.024 0.040 0.03G 0.035 w :c Child 0.062 0.321 0.059 0.069 0.061 0.060 Infant

• 0.099 0.113 UUN 0.730 0.115 0.099 0.097 .

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15.4.1 Loss-of-Coolant Accident '

The applicant has selected and analyzed a hypothetical design-basis LOCA and Ii has shown that the distances to the exclusion area boundaries and t population zone (LPZ) boundaries are sufficient to provide reasonable assurance that the radiological consequences of such an accident are within guidelines set forth in 10 CFR 100.11(a)(1) and (2). The analysis has included the

. following sources and radioactivity transport paths to the atmosphere:

(1) contribution from cantainment leakage (2) contribution from post-LOCA leakage from ESF systems outside containment The staff's review confirms the applicant's finding based upon the following:

(1) the applicant's provisions for and design of the containment system, and the acceptability Section 6 of this of the auxiliary building exhaust system.as described in report (2) the staff's independent analysis of the radiological consequences of a hypothetical design-basis LOCA as described below.

15.4.1.1 Containment Leakage Contribution The Byron station includes a containment design to minimize the leakage of fission products from a postulated design-basis LOCA.

The containment consists of a post-tensioned concrete primary containment vessel with a carbon steel liner. f. -

with 'an NaOH additive to enhance the removal of iodine in the lowing a LOCA.

LOCA used the conservative assumptions of Positions C.1.a throu Regulatory Guide 1.4, Revision 2, " Assumptions Used for Evaluating the Poten-tial Radiological Water Reactors." Consequences of a Loss of-Coolant Accident for Pressurized The primary containment was assumed to leak at a rate of 0.1hours.

24 percent /per day for the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and 0.05 percent /per day after The fraction of core inventory available for release was assumed to be 25 percer.t for iodine and and 100 percent for noble gases. The analysis took into account radiological decay during holdup in the containment, mixing in the containment, and iodine decontamination by the ESF spray system. A list of assumptions Table 15.2. used in the calculation of the LOCA doses is given in 15.4.1.2 Post-LOCA Leakage from ESF System Outside Containment s .-

As part of the LOCA, the staff has also evaluated thel consequences of leakage cf containment sump water which is circulated by the ECCS af ter that postulated accident.

During the recirculation mode of operation,"the sump water is circulated outside containment to the auxiliary building. If a leak should develop, such as a pump seal failure, a fraction of the iodine in the water could become airborne in the auxiliary building and exit to the atmosphere.

For Byron, the ECCS area in the auxiliary building is served by an ESF air filtration system (the auxiliary building exhaust system). Therefore, doses ,

from passive Appendix B). failures were not considered (as specified in SRP Section 15.6.5, t

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. Byron SER 15-12

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the routine amount of leakage from ECCS equipment Using the information in the SRP, the staff evaluated the potential radiological consequences the applicant's value from(7520 this release cc/hr). pathway assuming a routine leakage rate of twic The resultant radiological consequences were to the only 2.7atrems thyroid to the thyroid at the exclusion area boundary and 1.1 rems the LPZ.

consequences from normal ECCS component leakage The at a lea resulting radiological consequences were 77 rems to the thyroid at the excl area boundary and 31 rems to the thyroid at the LPZ.

15.4.1.3 Conclusions

.- Thegiven

.are staff's calculated in Table 15.2. thyroid and whole-body doses from the hypothetical L clusion area and to theThe LPZstaff concludes boundaries ofthat the the distances Byron site, in to the ex-conjunction with the ESFs of the Byron station design, are sufficient to provide reasonable within the exposure guidelines set forth in 10 CFR 100.11.ensura based on the staff review of the applicant's analyses and This onconclusion is an independent analysis within the performed guidelines. by the staff to verify that the total calculated doses are s -

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. b Byron SER

.. 15-14

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Table 15.1 Radiological consequences of design-basis accidents O

Exclusion area low population boundary, rems zone, rems Postulated accident Thyroid Whole body Thyroid Whole bcdy loss of coolant:

Containment leakage 0-2 hr 0-8 hr 172 5. 0 -

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. 8-24 hr 12.1 0.34

~

24-96 hr 3, 9 0,07 96-720 hr 3.1 0.02 2.7 0.01 Total containment leakage 172 5.0 22.0 0.44 ECCS component leakage 2.7 '

0.01 1.1 0.01 Total 175 5. 0 23.0 0.45 Steamline break outside secondary containment Long-term operation case (Case 2) 12 Short-term operation case 0.1 1.0 0.1 O (Case 3)

Control rod ejection 16 0.1 1.0 0.1 Containment leakage pathway 50 , 0. 2 Secondary system release 15 0.1 pathway 39 0. 6 Fuel-handling accident 1.3 0.1 in fuel-handling area 29 0.6 1. 0 ' O.1 Small line break 5.7 0.1 0.2' O.1 Steam generator tube rupture Case 1 (DEI-131 at 60 pCi/gm) 61 Case 2 (DEI-131 at 0.1 2. 6 0.1 1 pCi/gm) 11 0.1 0.6 0.1 x ..

The short-term diffusion estimates (X/Q's) used in the analysis are those presented and discussed in SER Section 2.3.4.

The meteorological models described in regulatory guides references in these analyses are modified by these presented in Regulatory Guide 1.145.

discussion of the meteorological models. See Section 2.3.4 for further O *

. Byron SER 15-11

, , . - - , - , ,, - - r - - , - ---e - -

e-.-

MGE W

. ,rgy ;Syfyy- _f Table 15.2 Assumptions used in the cat'culation of p)

.. loss of-coolant accident doses Parameter and unit of measure Quantity Containment leakage Power level, MWt 3565 Operating time, yr 3

Fraction Iodineof core inventory available for containment leakage, %

Noble gases 25 100

... Initial iodine composition in containment, %

Elemental Organic 91 Particulate 4 5

Containment leak rate, %/ day 0-24 hr ,,

After 24 hr 0.1 0.05 Containment volume, ft3 Sprayed volume , .,

Unsprayed volume 2.35 x 106 4.1 x 105 Containment mixing rate from cooling fan operation, cfm 180,000 Containment spray system Maximum elemental iodine decontamination factor 100 Spray removal coefficients, hr 1 Elemental iodine Particular iodine 10 Organic iodine 0.45 O

Relative concentration values, sec/m 3 0-2 hr at the exclusich area boundary '

6.8E-4 0-8 hr at the LPZ boundary 8-24 hr at the LPZ boundary 2.3E-5 24-96 hr at the LPZ boundary '.

• 1.5E-5 96-720 hr at the LPZ boundary 6.4E-6 1.9E-6 ECCS leakage outside containment Power, FMt . ~

3565 Sump volume, gal 484,000

-Flash fraction * '

'.1 0

Le'ak rate, gph (twice the maximum operational leakage defined in FSAR Table 15.6-15a) -

2.1 Leak duration, hr *

• 720 Delay time, hr 0.50 Filter efficiency for iodine, %

Elemental and particulate .

Organic iodine - 90 50 Byron SER 15-13

.