ML020570184

Meeting with Duke Energy Corp., Catawba Nuclear Station, Units 1 and 2 Result of Control Room In-Leakage Testing, Implementation and Alternate Source

ML020570184
Person / Time
Site:	Catawba
Issue date:	02/21/2002
From:	Chandu Patel NRC/NRR/DLPM/LPD2
To:	NRC/NRR/DLPM/LPD2
References
TAC MB3758, TAC MB3759
Download: ML020570184 (30)

Text

NRC FORM 658 U.S. NUCLEAR REGULATORY COMMISSION (9-1999, TRANSMITTAL OF MEETING HANDOUT MATERIALS FOR IMMEDIATE PLACEMENT IN THE PUBLIC DOMAIN This form is to be filled out (typed or hand-printed)by the person who announced the meeting (i.e., the person who issued the meeting notice). The completed form, and the attached copy of meeting handout materials,will be sent to the Document ControlDesk on the same day of the meeting; under no circumstances will this be done later than the working day after the meeting.

Do not include proprietarymaterials.

DATE OF MEETING The attached document(s), which was/were handed out in this meeting, is/are to be placed 2.12110 2- in the public domain as soon as possible. The minutes of the meeting will be issued in the near future. Following are administrative details regarding this meeting:

Docket Number(s) - J , D- L4\4 Plant/Facility Name Cu. (. \ -a. U,'r_, - li,o L TAC Number(s) (ifavailable) rý "v7t-il y ,M(S "t,"7 :ý-5 Reference Meeting Notice - .

Purpose of Meeting (copy from meeting notice) T- QkA, C_4,S b 44. YAis ' a.n4'PI "

NAME OF PERSON WHO ISSUED MEETING NOTICE TITLE OFFICE N 2.

DIVISION BRANCH Distribution of this form and attachments:

Docket File/Central File PUBLIC NRC ORM65819-999 P~NTEOON ECYLEDPAPR ma frm ws dsiged sin Inorm NRC FORM 658 (9-1999) PRINTED ON RECYCLED PAPER This form was designed using InForms

Control Room Ventilation Testing 02/21/02 1:00 PM to 3:30 PM Washington, DC

_________________________________________________________I Meeting requested by: Duke Energy Type of meeting: Working level Attendees: NRC: Chandu Patel Duke: Margaret Chernoff, Steve Schultz, Jim Kammer, Robert Banker Agenda topics 1:00-1:10 PM Meeting Overview Jim Kammer 1:10-1:15 PM Introductions Jim Kammer 1:15-1:20 PM Introductions NRC 1:20-1:35 PM Control Room Envelope and Control Jim Kammer 1:35-1:50 PM Control Room Ventilation System Jim Kammer 1:50-2:15 PM Control Room Unfiltered Inleakage Jim Kammer 2:15-2:25 PM Break 2:25-2:45 PM Component Testing Jim Kammer 2:45-3:05 PM Tracer Gas Testing Jim Kammer 3:05-3:25 PM General Discussion 3:25-3:30 PM Closing Comments Jim Kammer 3:30 PM Adjourn

Catawba LARS (Current)

Fuel Handling Accident Analysis - Under Review Annulus Ventilation - Expected 9/2002 submittal Auxiliary Building Ventilation - Expected 9/2002 submittal UFSAR Dose Analysis - reconstitution effort underway - Expected 9/2002 submittal Discuss Catawba Control Room Unfiltered Inleakage Test Results validated.

Dose Analysis Reconstitution Assumptions for Unfiltered Inleakage have been ductwork integrity.

Current HVAC Ductwork Maintenance Programs are adequate with respect to maintaining Recommended ANSI N-510 type test frequency approximately 20 years.

Unnecessary to perform periodic tracer gas test.

1:20-1:35 PM Control Room Envelope and ('ontrol JIM

[lalltiwiil Discussion:

boundary doors typically open 594 Auxiliary Building - Single elevation, very simple physical boundary, one room inside Adjacent Areas Service Building - OAC Room, Security Computer Room, Hallways, Office Area (VJ, balanced) 594 Electrical Penetration Rooms (VC, balanced)

Auxiliary Building - general areas (VA, slight vacuum)

Cable Spreading Rooms - (VC, balanced)

VC/YC Equipment Rooms - (VC, balanced)

Outside - very short section of wall, no penetrations, roof (NA, ambient)

Major VC System Components located outside of Control Room pressure Non-Control Room Ductwork traverses Control Room in overhead, pressurized and negative Instrument Air Control Room Testing (Current)

Technical Specification Filter and Flow Testing Technical Specification Pressure verified to adjacent areas Pressure trended to identify need for corrective maintenance Periodic system inspections

B-TRAIN A-TRAIN VC/YC VC/YC EOUIPMENT EOUIPMENT ROOM ROOM AUX BUILDING CORRIDOR mz z0 m a aj1 ;.

SNUBBER TESTING AREA OPERATOR AID COMPUTER ROOM OUTSIDE SECURITY COMPUTER ROOM CNS CONTROL ROOM LAYOUT

FLOOR BENEATH CNS CONTROL ROOM (CABLE ROOMS ELEV. 574)

1:35-1:50 PM Control Room Ventilation system Discussion:

Basic Components with non-essential makeup PEF - Pre-filter/Moisture removal, HEPA, Heater. C-irbon Bed. HEPA. loop seals PEFT Fan - 6,000 cfm nominal, essential power, Vaneaxial Fan (no shaft seals) seals), loop seals - condensation makeup CR-AHU - 26,000 cfm nominal, essential power, internal fan (no shaft Envelope CRA-AHU - 75.000 cfm nominal, essential power. not in Control Room Ductwork is welded seam design with bolted flange connections Normal Operation Continuously pressurized Continuously filtered One complete VC Train inservice Maintenance Alignment Design Basis Accident Operation Outside Air Intakes - Recent Chlorine Amendment Maintenance Testing Requirements performed Control Room Pressure verified any time maintenance alignment is Smoke Test VC Components any time VC Pressure Boundary is opened.

Potential Unfiltered Inleakage Sources Catawba Nuclear Station Control Room Ventilation System 1CRA-D-7 COOLINd COIL I FILTER C) 0 J, 6 P*

cc ?z C) 0 CC Unit 1Air Outside Intake 2CR-D-3 1CRA-D-81 AFmC 1CR-AFMD-4 1 VC-5B 2TX 1*VC-6A ICRA-D-1

"A" Train & "B" Train Inleakage Test Boundary Catawba Nuclear Station Control Room Ventilation System 1CRA-O-7 2CRA-D-7

/ /Tw

< COOLING COIL FOILTER C) FILTER Pl D coo0 IN(t

, COIL FILTER C)le UK E

cc Cc) 0_____

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cc0 Unit 1 Air Outside Unit 2 Intake Outside Air Intake HEPA

'7Z I 2CR-0-3 1CR-D-3 GARBOt 1CRA-D-8 2CRA-D-8 1CR-AFMD-3L-AFMDj AF-M 2CR-AFMD-3 HEPAA i AFMD AFMD Xl *HEATEF 1 CR-AFMD-4 2CR-AFMD-4 PREFIL R 1VC- *5 VC-7B 2VC-5B Test Area VC-6A 2VC-6A L.J !Blank 1CRA-D-1

Control Room Area Inleakage Test Boundary Catawba Nuclear Station Control Room Ventilation System ICRA-D-7 2CRA-D-7 CRA -CRA

, ]*'**

• 1CR-D-4 COOLING 2CR-D-4 4-N\N, ' 1 i COOLIN COIL~~

< COIL FILTER L-FILTER

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<D _COOL__. "COIL-Cob-LIN~ VT

< ___COIL cr FILTER Y FILTER1 Control Room

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Unit 2 CCRAI r ~R-A) Unit 1Air Outside Outside Air TI Intake Intake 1VC-8A 2VC-71 HEPA

ýHERA 2CR-D-3 1CR-D-3 CARBON ICRA-D-8 I -~

2CRA-D-8 1CR-AFMD-3F AFMO HEP AFMDO 2CR-AFMD-3 HERA AFMD Test Area

-z HEATE-R 1CR-AFM4-4 CR-AFMD-4 HEATER I --I Z:ý.A PRE-FILTT R 2VC-8 I Blank 1VC-7BR PRE--FILT'ER 1VC-5R>+

X_,~ 2\/C-513 <.*

S... ...

• 1VC-6A V-B 2VC-6A 2CRA-D-1 j 1CRA-0-1

Control Room Unfiltered Inleakaoe Jim Kammer 1:50-2:15 PM Discussion:

Control Room Unfiltered Inleakage Dose Analysis Reconstitution Value 100 cfm 10 cfm Door Opening (SRP) Assumed value 30 cfm Instrument Air Calculated value based on calculated air consumption plus mar-in 60 cfm VC System Leakage Measured Value =40 scfm No leakagle assumed through doors, walls, etc due to control room pressure 30 scfm Calculation/walkdown has determined Instrument Air Leakage in Control Room Calculated Consumption ý 15 scfm Aging Margin 2X due to flow path.

Measurement not considered to be necessary based on low dose impact of this inleakge path Air Compressor - Washout Air Dryers Long tubing runs Tight clearances in final devices located in control room Catawba Testing 4/11/01 Pressure mapping of "A" Train 7/25/01 Pressure mapping of "B" Train 8/06/01 "A" Train Component Testing (ANSI N-5 10) 8/13/01 "B" Train Component Testing (ANSI N-510) 8/28/01 Integrated Tracer Gas Test 9/3/01 Investigation onto "B" Train Intake Low Flow 9/9/01 "A" Train flow balance to address AFMD error 9/12/01 "B" Train flow balance to address AFMD error 12/3/01 "CRA" Duct Component Testing, "B" Train pressure mapping 1/10/02 "A" Train flow balance, "A" Train pressure mapping

Conclusions:

Person responsible: Deadline:

Action items:

2:25-2:45 PM Component Testing Jim Kammer Discussion:

Test Method ANSI N-510 Re-balance recirculation line flows for single recirculation line Isolate Test Boundary Install blanks in ductwork Draw constant negative (CRA duct will be positive) pressure on ductwork Identify leaks and repair Measure flow Remove Blanks Unisolate Test Boundary Re-balance recirculation line to "As-Found" Three test sections "A" Train 13.0 + 0.4 scfin @ 7.0 inwc =16 scfm @ 10.0 inwc "B" Train 15.5 +_0.4 scfm @ 7.0 inw,,c =19 scfin @ 10.0 inwc CRA Ductwork 19.5 + 0.4 scfmn Ca2.5 inwc = 19.5 scfn Oa 2.5 inwvc Total Duct Inleakage 40 scfm (maximum11 of "A'" or "B'"Train + CRA)

Test Findings "A" Train Minor leakage fouTnd/repaired on discharge ofePF fan. Would not have resulted in unfiltered inleakapi.

"B" Train l~eakage found/repaired at PFt" Discharge damper. Attributed to inadequate damper repair in 1980's.

(Not Unfil ntenakae. Proior to establishment of current VAin Duct maintenance program)

"CRA" Leakage found and repaired at electrical heater box (design deficiency), damper shafts. (Unfiltered inleakage)

Conclusions:

Test adequate to quiantify Unfiltered inleakage Perform Component 'rest at 20 year intervals based on:

Test was conducted "As-Found" (ie no precondition ingg).

Current Maintenance Program validated as adequate to maintain duct integrity.

Conservatively 50%-/ margiin to Dose Reconstitution Unfiltered Inleak-age Assumptions.

Action items: Person responsible: Deadline:

2:45-3:05 PM Tracer Gas Testing Jim Kammer Discussion:

Test Vendor NuCOn Recommended test method: Continuous Injection Estimated test accuracy (Best Case) + 90 cfm.

Actual test error + 280 scfm Envelope Leak Flow Outside Air Est CRA Recirculation Unfiltered Leakage "A" Normal 2946 +/- 100 scfm 2803 scfrn 505 scfmn -360 scfm "A" Maintenance 32 19 _+93 scfrn 2709 scfm 480 scfm 30 scfm "B" Normal 2647 +/-+92 scfmn 2494 scfm 3S63 scfm -230 scfm "B" Maintenance 3020 +/-_ 110 scfm 2536 scfm 588 scfm -100 scfm "A" + "B" (ESF No Failures) 5168 + 180 scfm 3826 scfrn 1390 scfmn -48 scfm Engineering Issues with Tracer Gas Test PFT to CRA Flow Path complicates test conduct and requires numerous flow rates to be measured.

Several flows could not be measured accurately due to either injection point location or inadequate mixing.

Limited Control Room Access to ensure best possible results Poor Test Accuracy

Conclusions:

Action items: Person responsible:

3:25-3:30 PM (,IlosinC Cornments Discussion:

Dose Analysis Reconstitution Assumptions for Unfiltered Inleakage have been validated.

ductwork integrity.

Current ItIVAC Duct\mork Maintenance Programs a, , adequate with respect to maintaining Recommended ANSI N-5 10 type test frequency approximately 20 years.

Unnecessary to perform periodic tracer gas test.

CATAWBA NUCLEAR STATION FHA AND WEIR GATE DROP ACCIDENT REG GUIDE 1.183 APPENDIX B ANALYSIS PRESENTATION TO NRC FEBRUARY 21, 2002 DETAIED DISCUSSION MATERIAL RECOMMENDED BY STAFF ON FEBRUARY 19, 2002 METEOROLOGICAL DATA AND ANALYSIS DOSE ANALYSIS DISPERSION FACTOR ANALYSIS Dr. Stephen P. Schultz Marsha Kinley Mark Costello III Manager, Radiological Engineering Duke Power Company Charlotte,NC spschultz@duke-energy.com PDuke oPower,

General Features of the AST FHA Analyses DOSE ANALYSIS DISPERSION FACTOR ANALYSIS

• Regulatory Guide 1.183 approach with detailed information provideld in the LAR additional detail to follow today M FHA analysis represents first of the CNS AST submittals based on substantial analysis effort

• Dose analysis methodology by Duke Power

.X/Q analysis by Duke Power Environmental

• FHA calculation origination by DE&S

• Isotopic evaluations by NISYS & Duke Power 9LOCADOSE dose analysis software (Bechtel)

"* Full Systems evaluation and failure analysis

"* Traditional assumptions for assembly failures in FHA and weir gate drop event

• Results of analyses within Regulatory guidelines for offslte and control room dose m Analysis submittal addition will address pool DF of 200 Duke

• Results will continue to be acceptable O'Power,

METEOROLOGICAL QUESTIONS the calculation Some questions were asked by the NRC Staff meteorologist (2/19/02) concerning air of atmospheric dispersion factors for transport of radioactivity to the control room outside intakes. These questions and responses are as follows:

of high

1. Providejustification that, overall, the meteorological data used in the assessment are was applied.

quality and suitablefor use in the assessment of atmospheric dispersion to which it the measurement program meet the For example, during the periods of data collection did factors such guidelines of Regulatory Guide 1.23, "Onsite MeteorologicalPrograms," including and as maintaininggood siting, instruments within specifications, and adequate data recovery quality assurance checks?

with The Catawba Nuclear Station meteorological system is maintained to comply Regulatory Guide 1.23. The meteorological equipment in use is of high quality, has been maintained within operating specifications to ensure accurate data collection and the tower the sensor instruments are free of obstructions. Annual meteorological data recoveries for period 1994 through 1998 were approximately 96.8%, 95.7%, 95.4%, 96.5%, and 95.1%

respectively. Weekly meteorological system checks are performed to ensure all data are channels are operating within tolerance. Semi-annual meteorological system calibrations performed during which all tower-mounted sensors are replaced with newly certified sensors.

The precipitation gauge is the only sensor not located on the tower and is calibrated in place, and without replacement. All collected meteorological data are reviewed, validated, edited by archived. Prior to the archival process, the meteorological data is reviewed and approved the Certified Consulting Meteorologist in-house.

a. During the periods of data collection, was the tower areafree from obstructions (e.g. trees, the structures) and micro-scale influences to ensure that the data were representative of overall site area?

tower The meteorological tower area has been maintained free of obstructions. The original (40m) in use through 6/10/96 was replaced with a new tower (60m), which began operation on 6/11/96 at 1900 hours0.022 days <br />0.528 hours <br />0.00314 weeks <br />7.2295e-4 months <br />. These towers are located on a hill south of the station, which offers the best siting available.

and

b. If deviations occurred, describe such deviationsfrom Regulatory Guide 1.23 guidance why the data are still deemed to be adequate.

not During the meteorological data quality assurance process, if meteorological data did satisfy Regulatory Guide 1.23, then the meteorological data would be deleted. Missing data were values (e.g. 999s) would be inserted in the historical/archive database. No data values maintained that did not satisfy regulatory criteria.

systems

c. What quality assurance checks were performed on the meteorologicalmeasurement prior to and during the periods of collection to assure that the data are of high quality?

were Weekly meteorological system checks were performed to ensure all data channels operating within tolerance. Semi-annual meteorological system calibrations were performed The during which all tower-mounted sensors were replaced with newly certified sensors.

page 1 2/19/02

precipitation gauge is the only sensor not located on the tower and was calibrated in place, edited and without replacement. All collected meteorological data were reviewed, validated, approved archived. Prior to the archival process, the meteorological data was reviewed and by the Certified Consulting Meteorologist in-house.

guideline

d. Were calibrations properly peforined and instruments found to be within specificationsfor the use of the data?

Weekly checks and semi-annuals calibrations assured that instruments were operating within tolerance. Any out-of-tolerance conditions would prompt data deletion.

on the data

e. What additional checks and at what frequency were the checks performed to assure following collection and prior to input into the atmosphericdispersion calculations data of questionable quality, and identifying any problems in a timely manner, flagging assuring that data were correctlyformattedfor the calculations?

collected Routine quality assurance checks were performed on the meteorological system and archive data as described above. Meteorological data were retrieved from the quality assured of the hourly data files and provided for use in the air dispersion calculations. The format to and missing data values were considered in the calculation, when the data was converted the required format for input into ARCON96.

(i.e. delta Hourly stability classes were calculated based on the vertical temperature gradient T) measurements, and the data was converted and formatted utilizing an in-house SAS program and MS EXCEL. Input to ARCON96 treated missing data as blanks. Per NRC Staff request (2/19/02), the data will be provided in Arcon96 format with missinf data fields filled in with 9's to verify conservative results were obtained (Computer CD).

2. During the 1994 through 1998 time period, there appear to be some intermittent and very measurements of very unstable lapse rates (A and B stability classes) during the night stable lapse stable lapse rated (F and G stability classes) during the day. Typically, neutral or such rates occur at night and neutral or unstable conditions during the day. Did Duke observe occurrences during their review of the data? If so, to what is this attributed?

Response

30 Duke will re-examine the data to identify these occurrences (approximately occurrences) and determine their validity.

to

3. When using ARCON96 are distances the shortest distancefrom postulated release location the intake location?

(crow's Response: All distances entered into the ARCON96 input files were the shortest intake flight) horizontal distances. Elevation differences between the release points and the locations were entered as appropriate.

2/19/02 page 2

Additional Meteorological and Calculation Information

1. All sources are treated as "ground-level" releases in this calculation.

Table I Sources Source 1 Equipment Hatch (EQ) 2 Fuel Building (FUEL) 3a Unit Vent- with VA flow rate (UV) 3b Unit Vent - with VF flow rate during fuel handling accident (UVF)

Table 2 Source Characteristics and Arcon96 Inputs Source Type: EQ FUEL UV UVF Vertical Point X X W.

Horizontal or Capped Point I-CR2 2oCRI HorizontalArea Source x

Xý Vertical Area Source i

Release Height 6.32 m 0m 20 m 38m 38 m Flow Rate (m3/s) 0 0 2.83 15.64 Sigma-Y 0m 3.2m Om 0m lm Sigma-Z 0m 3.3m i Gm Om Im Bldg Cross-sectional Area 2 1592 m2 1592 m 1592 m 2 1592 m2 0 0 0 0

Source/Stack Radius* (in) 0 mi/s 0 m/s 0 m/s 0 m/s 43I Vertical Vel.*

1-CRI DistanceWD 46 marc 80m I 43530m I 43 530mn 900 arc 830 128 m 109 m 109 m 1-CR2 DistanceWD 125 m 1420 1630 1630 1650 128 m 109 m 109 m 2-CRI DistanceWD 125 m 200 170 400 200 80 m 43 m 43 m 2-CR2 DistanceWD 46 marc 970 1290 1290 900 arc Values of zero are assumed for the vertical velocity and stack radius parameters, in order to treat the release as a ground-level release in ARCON96.

Figure 1from the calculation is being provided in hardcopy, showing the plot plan of Catawba Nuclear Station.

page 3 2/19/02

In this calculation, all distances are the straight-line horizontal distances from source to receptor, except for releases from the equipment hatch to receptor intakes on the same unit, in which case the flows the flow must go around the containment building to reach the closest air intake. For directions.

around containment, wind directions are also different from the straight down-wind All distances and directions are rounded to whole numbers. For hor'zontal and vertical area sources, the distance to the closest edge of the source is input as the horizontal as the distance. Note that the distance to the equipment hatch deviates from this practice, horizontal distance is measured from the equipment hatch centerline. ARCON96 uses the it treats as a virtual distance to calculate an effective distance to the area source, which point source farther upwind.

north All wind directions are measured from True North. The difference between station and True North is noted on Figure 1 as 1 degree 11 minutes and 5 seconds west of station north at CNS.

Table 3 Summary of ARCON96 Default Settings for CNS Parameters Default Values Used Surface Roughness Length 0.2 m Wind Direction Window (degrees) 90 degrees Minimum Wind Speed (m/s) 0.5 m/s Averaging Sector Width Constant 4.3 Initial Diffusion Coefficients *

• Source-specific. See above table.

• Hours in Averages 1, 2, 4, 8, 10, 24, 96, 168,360, 720 Minimum Number of Hours 1, 2, 4, 8, 9, 22, 87, 152, 324, 648

/1 n ' page 4 L/ I

• Z

2. (X/Q)s for the non-standard averaging periods were obtained from the ARCON96 output.

This is done by interpolating between the results for the bounding time periods (e.g. (0-a) and (0 b)) to obtain the desired averaging period (e.g. "a to b hours"), as in the equation below.

(X/Q) for period [a to b] = b(X/Q)b - a(X/Q)a ] / (b-a) where a, b hours bounding the desired averaging period (X/Q)a, (X/Q)b 95th percentile (X/Q)s for the time periods "0-a" & "0-b" (X/Q) for period [a to b] interpolated, average (X/Q) for the period [a-b hours].

Thus, the following equations are used to determine the (X/Q)s from the ARCON96 output for the desired time intervals.

Table 3 (X/Q) Determination from ARCON96 for Desired Averaging Intervals CNS Time after Accident X/Q Determination 0-2 hours max of 1-hour or (0-2 hour) modeled X!Q 0 - 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> (0-8 hour) modeled X/Q 8 - 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> [ 10(X/Q)O 8(X/Q)0-8] / 2 10 - 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> [24(X/Q)0-2 4 - 10(X/Q)o-10 ] / 14 1 - 4 days 95th percentile (1 - 4 days) modeled X/Q 4 - 30 days 95th percentile (4-30 days) modeled X/Q

3. During the multi-year meteorological period used as input to the ARCON96 model i(1994 1999), the height of the upper measurement level at Catawba Nuclear Station increased from approximately 40m to 60 in. A taller tower became operational at CNS on June 11, 1996 at hour 1900. This increased the separation distance for the delta-T measurements used for stability class classification from 30m to 50 m (e.g. 60m - 10m = 50m). Therefore, in processing the meteorological data, the changes in the delta-T ranges for the stability classes were considered.

for For the "Upper Measurement Height" parameter in ARCON96, a value of 60m was entered not affect the the multi-year run. Since all releases were specified to be "ground-level" this does results, as the model uses the lower level winds (e.g. 10m level). Even if the release type is later changed, this will still be a conservative compromise between the tower heights, as the model would then assume lower wind speeds at greater heights within the surface boundary layer, and thus interpolate lower wind speeds for modeling at the release height.

Other input parameters to ARCON96 also provide assumptions about the meteorological conditions. The surface roughness length has a default value of 0.1 m in the model, but this was changed in this calculation to be 0.2m per the draft NRC guidance. The wind direction window width was input as the default, a 90 degree sector within which the plume is assumed to travel directly from source to receptor. The default minimum wind speed of 0.5 m/s was also used.

is Below this speed, winds are treated as calm by ARCON96 and wind direction is ignored; it then assumed by the model that the receptor is directly downwind of the source during calms.

2/19/02 page 5

and processing of Hourly

4. The following information details the initial format (Computer CD).

Meteorological Data performed prior to input into ARCON96 Duke Power Nuclear Stations A.1 Format of Archived Meteorological Data for onsite meteorological tower Hourly meteorological data from the nuclear station's have been performed. The format of is routinely archived after quality assurance reviews denoted by filling the variable's digits with this data is shown in Table A-1. Missing data is 10 m above ground level. Upper nines. Lower level winds are measured at approximately tower (e.g. approximately 40m and level winds are measured at the top of the meteorological from which the wind is blowing and is 60m historically). Wind direction is the direction Delta-T is the difference in temperature measured in degrees clockwise from True North. - lower temperature) and can between the two measurement heights (i.e. upper temperature Theta is the standard Sigma be used to derive an atmospheric stability classification.

that the dewpoint temperature is only deviation of the lower level wind direction. Note period.

measured at Catawba Nuclear Station for this time Nuclear Station Table A-1 Format of Meteorological Data for Catawba Missing Data Variable Example Column N/A Date and Time (YYMMDDhhhh) 9401010100 1 - 10 999.9 006.3 12 - 16 Upper Level Wind Speed (mph) 999 216 18-20 Upper Level Wind Direction (degrees) 999.9 003.3 22 - 26 Lower Level Wind Speed (mph) 999 226 28 - 30 Lower Level Wind Direction (degrees)

+0011.1 +9999.9 32 - 38 Sigma-Theta (degrees)

+00002.97 +09999.99 40 - 48 Delta-T (Celsius) +09999.9

+00001.2 50 - 57 Lower Level Temperature (°C) 59 - 66 Lower Level Dew Point Temperature (°C) +00000.2 +09999.9 0000.05 9999.99 68 74

- Precipitation (inches)

A.2 Input Format of Meteorological Data for ARCON96 be input to the ARCON96 model. The required Multiple years of hourly meteorological data can the day of the year and ranges from 1 to 366.

format is listed in Table A-2 below. Julian day is being zero (i.e. 00-23). Atmospheric The hour is entered using a 24-hour clock with midnight 1 to 7, respectively. Wind speeds are stability classes A-G are input numerically as classes without the decimal point (e.g. 5.3 mph would entered to the nearest tenth of a reporting unit, but units can be used for wind speed; units are be input as 53). Either m/s or mph measurement

(*.rsf).

selected in the run specification file for ARCON96 page 6 2/19/02

Table A-2 Required ARCON96 Meteorological Data In ut Format Column Fortran Format Variable 1 1X Blank 2 --6 A5 Site ID (alphanumeric) 7 -9 3X Blank 10- 12 13 Julian Day (ddd) 13 -14 12 Julian Hour (hh) 15 -16 2X Blank 17 -19 13 Lower Wind Direction 20 -23 14 Lower Wind Speed 24 iX Blank 25 - 26 12 Stability Class 27 -28 2X Blank 29 -31 13 Upper Wind Direction 32 -35 14 Upper Wind Speed A.3 Conversion of Meteorological Data to ARCON96 Input Format Before onsite meteorological data from a Duke Power Nuclear Station can be used as input to ARCON96, it must be processed to determine stability class, add Julian day and time, and remove the decimal point from the wind speeds. Missing data flags (i.e. variables filled with 9's) must also be eliminated and replaced with blanks.

Onsite meteorological data for the years 1994-1999 were used for Catawba Nuclear Station. Note that during this period, the old measurement system located on a 40m tall microwave tower was replaced by a new 60m meteorological tower located nearby. The new tower became operational at CNS on June 11, 1996 at hour 1900. The change in height of the upper level measurement system was factored into the stability class determination, as discussed below (see Table A-3).

Also note that 1996 was a leap year.

For preprocessing, each year of hourly meteorological data was read into an EXCEL spreadsheet in order to add the Julian day and corresponding hour. The data was then saved in text files (i.e.

• .prn) for input into a user-written SAS program, "ARCONMET". The SAS program converted the Delta-T measurements into associated stability classes, per the criteria listed in Table A-3 below, based on a standard classification scheme for a 100m vertical separation. The SAS program also removes the decimal point from the wind speed data by multiplying by 10.

Missing data flags are replaced by decimal points or dots (i.e. "."). A Site ID is also added to each line of hourly data. The text output files from the SAS program were then read into EXCEL to replace the missing data "points" with blanks. The EXCEL file was again saved as a text file (i.e. *.prn) for input into the ARCON96 model.

page 7 2/19/02

Table A-3 CNS Delta-T Ran :es for Determining Stability Clas!

CNS 40m Tower Delta-T (C) CNS 60m Tower Delta-T (C)

Stability Class I A = 1; Extremely Unstable dT< - 0.57 dT < - 0.97 B = 2; Moderately Unstable - 0.57 < dT < - 0.51 - 0.97 < dT < - 0.87

• r C = 3; Slightly Unstable -0.51 < dT<- 0.45 - 0.87 <dT < - 0.76 D = 4; Neutral - 0.45 < dT < - 0.15 - 0.76 < dT < - 0.25 E = 5; Slightly Stable -0.15<dT< 0.45 - 0.25 <dT < 0.76 0.45 < dT< 1.2 0.76 < dT < 2.04 F = 6; Moderately Stable G = 7; Extremely Stable 1.2 < dT 2.04 < dT 2/19/02 page 8

CAIC - IZZ7 (lO) I ev, / PqSe 6~f 2?

4 =-11'05" CALLED NORTH "TRUE NORTH AUXILIARY BLDG FWST FWST EQUIPMENT UNIT 1 UNIT 2 EQUIPMENT SHATCH UNIT 1.

VENT 0

o0C- 0

'EXTERIOR EXTERIOR' DOGHOUSE DOGHOUSE SERVICE BLDG UNIT 2 UNIT 1 TURBINE TURBINE BLDG BLDG SCALE 1" - 100' DUKE POWER CATAWBA NUCLEAR STATION I 11 " * "1 .... .. I .. . . . . .. .. .

PLOT PLAN FOR CONTROL ROOM HABITABILITY ASSESSMENT FIGURE: 1

. FIGURE: 1

DOSE ANALYSIS / DISPERSION FACTOR ANALYSIS QUESTIONS The following information is provided to document and supplement questions and responses relayed in a telecom with the NRC Staff meteorologist (02/19/02) pertaining to the Catawba Nuclear Station Equipment Hatch / Personnel Air Lock (EQH/PAL) License Amendment Request. These questions and responses are as follows:

doses to the

1) Provide docketed references to the X/Q's usedfor calculations of radiation Exclusion Area Boundary (EAB).

The EAB X/Q Response: The EAB X/Q appears in two docketed documents listed below.

listed in both submitted analyses is 4.78E-04 sec/mA3.

to U.S.

In 1996, Duke Power sent the following LAR to the NRC Staff: W.R. McCollum Nuclear Regulatory Commission, "Catawba Nuclear Station, Unit I Docket No. 50-413, allowance Technical Specification Change," January 26, 1996. This LAR requested a one time to operate the Containment Purge Ventilation System for Unit 12 in Mode 3 immediately request following the Steam Generator (S/G) Replacement Outage. In response to a Telecon the technical from the Staff, Duke Power sent one copy of three calculations supporting (Attachment justification in this LAR. One of them, CNC-1227.00-00-0066, lists the EAB X/Q 4 - pg. 3, 12, Attachment 8, pg. 4).

to U.S.

In 1997, Duke Power sent the following LAR to the NRC Staff: W.R. McCollum Nos. 50-413 Nuclear Regulatory Commission, "Catawba Nuclear Station, Units 1 and 2 Docket Tube Rupture and 50-414 Request for Facility Operating License Amendment Steam Generator TS 3.7.1.6) to Evaluation," March 7, 1997. This LAR requested a change to TS 3.7.4 (then approval to require all four S/G Power Operated Relief Valves be operable and also requested a Steam Generator Tube credit local manual operation of one failed closed S/G PORV following and also Rupture (SGTR). The Staff made one official Request for Additional Information to the official RAI, we made several telecom requests for more information. In response of the EAB provided input for the dose analysis of the SGTR in question, including a citation X/Q. This information is found in the letter "W.R. McCollum to U.S. Nuclear Regulatory (TAC Commission, "Catawba Nuclear Station, Units I and 2 Docket Nos. 50-413 and 50-414 Amendment M98107 and M98108) Request for Additional Information Regarding the License for the Steam Generator Tube Rupture Evaluation," April 2, 1997.

related to the The Staff wrote Safety Evaluation Reports in approving these LARs. In the SER sec/m^3. In the 1996 submittal, the NRC Staff described a calculated value for X/Q of 3.8E-04 value for X/Q SER related to the 1997 submittal, the NRC Staff quoted the submittal calculated of 4.78E-04 sec/m^3.

A The current value reported in the CNS UFSAR in Table 15-29 is 4.78E-04 sec/m^3.

values will be historical value of 5.5E-04 sec/m^3 appears elsewhere in the UFSAR. These completed and the dose updated or removed as the Alternative Source Term analyses are analyses are updated.

Page 1 2/20/2002

DOSE ANALYSIS / DISPERSION FACTOR ANALYSIS QUESTIONS

2) Show that you have the limiting control room X/Q for the design basis (DB)fuel handling accident (FHA) and weir gate drop (WGD). This control room X/Q is associatedwith releases from the unit vent stackfor all of the above design basis accidents. Discuss the effects of loss of offsite power and singlefailure in your control room X/Q.

Response: Only three release paths are associated with the Fuel Handling Accidents and Weir Gate as follows:

Fuel Handling Accident in Containment: (1) Release from the equipment hatch and/or (2) Release from the unit vent stack.

Fuel Handling Accident in the Fuel Building or Weir Gate Drop: (2) Release from the unit vent stack and/or (3) Release from the fuel building louvers.

the The control room X/Q associated with the unit vent stack exceeds the control room X/Q for equipment hatch by approximately 9% and the X/Q for the fuel building by a factor of 4. Some additional details are as follows:

Fuel Handling Accident in Containment: Credit is not taken for any safety related system except for the Control Room Ventilation System (CRAVS). However, the accident may occur with either the Containment Purge Exhaust System (CPES) on or off, with offsite power available or with loss of offsite power (LOOP). The CPES is non safety related.

For a FHA in containment with offsite power available and the CPES in operation, outflow from the containment will be drawn by the CPES fans into the unit vent stack. Note: no is credit is taken for the CPES filters in the dose analysis supporting this LAR. If the CPES not in operation at the time of the initiating event, the containment outflow will pass through either the personnel air lock doorway into the Auxiliary Building and thus to the environment through the unit vent stack or it will pass through the open equipment hatch directly to the environment.

If offsite power is lost with the initiating event, then the CPES containment isolation valves will fail closed. The sequence proceeds in a manner similar to the FHA in containment with CPES off. That is, the release is through the personnel airlock doorway to the Auxiliary Building and out the unit vent stack or directly to the environment through the equipment hatch doorway.

taken Fuel Handling Accident in the Fuel Building and Weir Gate Drop: Again, credit is not the accident may occur with for any safety related system except for the CRAVS. However, either the Fuel Handling Ventilation Exhaust System (FHVES) on or off, with offsite power available or with LOOP. The FHVES is a safety related system. It may be operated in the bypass mode or in the filtered mode. (Currently, the FHVES is operated in the filtered mode during fuel handling operations in the fuel building or during weir gate movement.)

For a FHA in the fuel building or WGD with FHVES in operation, outflow from the fuel for building will be blown by FHVES fans into the unit vent stack. Note: Credit is not taken 2/20/2002 Page 2

DOSE ANALYSIS / DISPERSION FACTOR ANALYSIS QUESTIONS the FHVES filters in the dose analysis. If the FHVES is not in operation at the time of the initiating event, fuel building outflow will escape to the environment primarily through the louvers and doorway penetrations in the back of the fuel building.

If offsite power is lost with the initiating event, one FHVES train will auto start. Then the release will be passed the fans of that FHVES train and out the unit vent stack.

2/20/2002 Page 3

DOSE ANALYSIS / DISPERSION FACTOR ANALYSIS QUESTIONS

3) Analysis assumptions related to control room intake configuration and availability:

Catawba is equipped with two CRAVS outside air intakes. The Class lE motor operated isolation valves in these intakes are open for normal plant operations. With the recent removal of the interfaces with the CRAVS chlorine detectors, there are no credible design basis failure modes which would cause any of these valves to fail close. However, one CRAVS intake could be closed for maintenance activity. The only restriction on the activity is that the valve be capable of being opened within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. As a result, only one intake was assumed to be available during the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> releases following either a FHA or WGD in calculating the TEDE's reported in the LAR.

In the Duke Power Company review of DG-1 111, we anticipated that Section 2.3.2 would contain Staff guidance regarding the treatment of unavailability for dual intakes. Currently, there is no Staff position or discussion pertaining either to failure modes which could cause unwanted closure of an intake or maintenance activity which could leave an intake closed at the initiation of a design basis event. Duke Power Company will include this among its comments on DG-1 111, which will be sent either as part of industry comments or separately.

4) Consideration of the Reactor Building as a potential release source:

How has the Reactor Building, being a distance of only 2 meters from the outside air intakes, been consideredas a potential release sourcefor the FHA in containment?

The Catawba Nuclear Station containment design and operation, which includes dual containment barriers with an annulus ventilation system, was examined in the containment FHA with the following conclusions. The only potential releases from the containment to the environment are through the following release points:

1) Annulus - Annulus Ventilation System - unit vent stack. This is not a release pathway for the FHA as the Annulus Ventilation System is not in operation for this accident.

2) Bypass leakage through containment penetrations into the Auxiliary Building. This pathway releases to the environment through the unit vent stack.

3) Bypass leakage into the Steam Generator Doghouses and into the yard near the outside air intakes.

4) Bypass leakage through the intake vents of the Containment Purge Exhaust System (CPES).

If the CPES is in operation, there is no outflow, only inflow. If the CPES is not in operation or if a LOOP occurs, the containment isolation valves for these penetrations are closed.

The out leakage through paths (2), (3), and (4) is credible only for LOCA and Rod Ejection when the containment may be pressurized. In particular, outflow through these paths are not credible for the FHA in containment. They are not relevant for the FHA in the fuel building or the WGD.

2/20/2002 Page 4