ML20084M511

Monthly Operating Repts for Mar 1983

ML20084M511
Person / Time
Site:	Sequoyah
Issue date:	04/14/1983
From:	Dupree D, Eddings M, Mason C TENNESSEE VALLEY AUTHORITY
To:
References
NUDOCS 8306020197
Download: ML20084M511 (27)

Text

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, TENNESSEE VALLEY AUTHORITY DIVISION OF NUCLEAR POWER SEQUOYAH NUCLEAR PLANT 1

MONTHLY OPERATING REPORT MARCH 1, 1983 - MARCH 31, 1983 UNIT 1

! DOCKET NUMBER 50-327 I

LICENSE NUMBER DPR-77 1

UNIT 2 DOCKET NUMBER 50-328 l

LICENSE NUMBER DPR-79 l

Submitted By: .

, Power Plant Superintendent 8306020197 830434 gDRADOCK 05000327 PDR

o TABLE OF CONTENTS Operations Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Significant Operational Events . ..................... 1-5 PORV's and Safety Valves Summa ry . . . . . . . . . . . . . . . . . . . . . 5 Licensee Events and Special Reports ................... 5-7 Offsite Dose Calculation Manual Changes ................. 7 Operating Data Unit 1 ............................... 8-10 Unit 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-13 Plant Maintenance Summary . . . . . . . . . . . . . . . . . . . . . . . 14-17 Documentation for ODCM Changes . . . . . . . . . . . . . . . . . . . . . 18-24 4

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Oparations Summary March, 1983 The following summary describes the significant operational activities for the month of March. In support of this summary, a chronological log of significant events is included in this report.

Unit 1 Unit I was critical for 631.9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />, produced 713,580 MWH (gross),

resulting in an average hourly gross load of 1,133,746 kW during the month.

There are 231.25 full power days estimated remaining until the end of cycle 2 fuel. With a capacity factor of 85 percent, the target EOC exposure would be reached December 29, 1983. The capacity factor for the month was 82.5 percent.

i There was one reactor scram, no manual shutdowns, and two power reductions during March.

Unit 2 Unit 2 was critical for 744.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />, produced 840,220 MWH (gross),

resulting in an average hourly gross load of 1,129,328 kW during the month.

There are 107.17 full power days estimated remaining until the end of cycle 1 fuel. With a capacity factor of 85 percent the target E0C exposure would be reached August 5, 1983. The capacity factor for the month was 97.1 percent.

There were no reactor scrams, no manual shutdowns, and three power l reductions daring March.

Significant Operational Events Unit 1 Date Time Event 03/01/83 0001 Reactor in mode 1 at 100% power pro-ducing 1170 MWe.

l 03/11/83 1535 Performed SI-78, Power Range Neutron l Flux Channel Calibation by Heat Balance Comparison (Daily). Esca-l lated reactor power from 98.5% to l 100% actual.

2200 Reactor at 100% power producing 1190 MWe.

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Significent Optretienal Evznts Unit 1 (Continued)

Date Time Event 03/14/83 0218 Began a load reduction to make a con-tainment entry to close the ice con-denser doors that blew open when purge was started.

0525 Reactor at 50% power producing 580 MWe and holding.

0645 Began reducing power to 30%.

0850 Reactor at 30% power producing 350 MWe.

1045 Began power ascension.

03/15/83 1615 Reactor at 100% power producing 1195 MWe.

03/16/83 1116 Ice condenser doors blew open, reducing power to enter lower con-tainment.

1328 Reactor was at 68% power and decreasing when a procedure error in SMI-0993 caused a reactor trip.

2010 Began cooling down to repair a bad source range detector.

03/17/83 0540 Reactor entered mode 4.

1125 Reactor entered mode 5.

03/18/83 1538 Reactor entered mode 4.

1939 Reactor entered mode 3.

03/19/83 0450 Began depressurizing the reactor coolant system to replace the ruptured UHI diaphram.

03/20/83 2101 Began filling the UHI system.

03/21/83 0535 Reactor take critical.

0804 Unit tied on line.

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Significant Operational Evants Unit 1 (Continued)

Date Time Event 03/21/83 1038 Reactor in mode 1 at 30% power and i holding 'for secondary chemistry to come into specification.

03/22/83' 0029 Began power ascension.

0620 Reactor at _52% power and hold to investigate the vibrations of the

1. 11 bearing (turbine).

i 0700 Began power ascension.

1058 Reactor.at 90% power and holding for calorimetric measurements.

j 1149 Began power ascension.

t 1530 Reactor at 100% power producing 1140 MWe. IC2 water out of service for i tube leak testing.

i-03/23/83 1215 102 water returned to service.

Reactor at 100% power producing 1190 MWe.

03/25/83 0503 1A2 water box out'of service for_ tube leak testing. Unit load dropped to-1143 MWe.

03/26/83 0950 1A2 water box returned to service.

Unit load 1190 MWe.

03/30/83 1345 Began reducing load to take IA'1 water box out of service for tube leak testing.

1355 Reactor at-94% power producing 1090 MWe. IB condenser vacuum pump tripped. Began returning 1A1 water-box to service.

1500 Reactor at 100% power producing'1190 MWe.

03/31/83 2359 Reactor in mode 1 at 100% power pro-ducing 1190 MWe.

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Significant Oparatiens1 Evrnts Unit 2

-(Continued)

-Date Time Event 03/01/83 0001 - Reactor in mode 1 at 98%. power pro-ducing 1174 MWe.

03/07/83 0408 All three #3 heater drain tank pumps tripped off when the Lo-Lo level-switch shorted out. Initiated a manual turbine roll back.

0409 Reactor at 75% power producing 900 MWe.

0630 Lo-Lo level switch repair com-pleted but still holding 73%

reactor power due to steam generator chemistry out of specifications.

0821 Began load reduction due to secondary chemistry.

1120 Reactor at 60% power producing 720 MWe and holding for secondary chemistry.

2355 Began power ascension.

03/08/83 0315 Reactor at 83% power producing-1020 MWe and holding to adjust the limit switch on LCV-6-105B.

0347 Began power ascension.

0558 Reactor at 98% power producing 1171 MWe.

03/12/83 1150 Began a load reduction to add oil to reactor coolant pump 2.

1420 Reactor at 32% power producing 358 MWe.

1900 Began power ascension.

03/13/83 0500 Reactor at 98% power producing 1172 MWe.

03/17/83 0745 Began a load reduction for maintenance-on loop PT-1-30.

Significant Oparstienni Ev:nts

• Unit 2 (Continued)

Date Time ' Event 03/17/83 1000 Reactor at 90% power producing 1095 MWe.

1340 Began power ascension.

1800 Reactor at 98% power producing 1170 MWe.

03/30/83 2015 Began reducing power for the incore/

excore calibration.

2200 Reactor at 75% power producing 918 MWe.

03/31/83 2359 Reactor in mode 1 at 75% power pro-ducing 918 MWe. Incore/excore cali-bration in progress.

PORV's and Safety Valves Summary Unit 1 The steam generator #1 PORV failed open during the reactor trip on March-16, 1983 and had to be closed by manual switch.

Unit 2 No PORV's or safety valves were challenged during the month.

Licensee Events and Special Reports The following Licensee Event Reports (LER's) were sent during March 1983, to the Assistant Director of Nuclear Power (Operations) for reporting to the Nuclear Regulatory Commission.

Unit 1 LER SUBJECT' SQRO-50-327/83022 Two of four UHI level switches were inoperable.

SQRO-50-327/83025 The shield building exhaust flow rate monitor 1-FT-30-242 was declared inoperable due to the loss of flow indication. The sense lines became blocked from dirt in the system.

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Liernsmo Ev:nts snd Sptcial R parts (Continued)

Unit 1 LER SUBJECT SQR0-50-327/83026 During the performance of SI-7.1, ERCW valve 1-FCV-67-66 failed to open due to a dirty contact.

SQRO-50-327/83029 Ice condenser lower inlet door _ zone D limit switches failed due to being out of adjustment.

SQR0-50-327/83031 RPI for control rod D-14 of shutdown bank A was declared inoperable due to a false indication.

The RPI female connectors on the reactor vessel head had their pen sleeves recessed into the connector.

SQR0-50-327/83035 One feedwater flow channel was declared inoperable due to failing low. A permanent comparison fitting on 1-FT-3-48A blew off causing the channel to indicate low.

SQRO-50-327/83036 Auxiliary building gas treatment system B train failed to meet the 99% methly iodine removal efficiency acceptance criteria.

SQR0-50-327/83037 Steam flow channel 1-FT-1-10B declared inoperable due to failing high due to air in the sense line.

SQRO-50-327/83038 Nonconformance report SQNNEB8212 was reissued to indicate the D/G's would become inoperable when the outside temperature is greater than 88*F.

SQR0-50-327/83039 The turbine building sump liquid effluent line radiation monitor was declared inoperable due to a leak in the pump.

SQRO-50-327/83040 Containment internal pressure exceeded 0.3 psid referenced to the annulus.

SQRO-50-327/83041 UHI level switches 1-LS-87-21, -23, and -24 found out of tolerance during SI-196.

SQR0-50-327/83042 The ice condenser inlet doors blew open during damper alignment for an incore instrument room purge.

SQRO-50-327/83043 Four 125v battery channels were declared inoperable because the weekly surveillance was not performed within its required fre-quency.

Licinaco Ev:nts and Spacial R ports (Continued)

Unit 2 LER SUBJECT SQRO-50-328/83017 Containment pressure relative to the annulus SQR0-50-328/83027 was greater than 0.3 psid.

SQRO-50-328/83033 SQRO-50-328/83023 UHI level switches 2-LS-87-21, -23, and -24 were found out of tolerance during SI-196.

SQR0-50-328/83024 Feedwater flow chanel 2-FT-3-103B failed low due to a bad zener diode.

SQR0-50-328/83028 While performing SI-151, the hydrogen recombiner kilowatt meter pegged high because the active filter failed.

SQR0-50-328/83030 Containment sump level channel 2-LT-63-177  ;

failed to meet channel check requirements due to air bubbles in the oil filled sense line.

SQR0-50-328/83032 All ice condenser doors opened when SI-28 was being performed on the containment air return fan.

SQRO-50-328/83034 The subcooling margin monitor was declared inoperable due to the loss of the plant com-puter.

j Special Reports There were no special reports transmitted during the month of March.

Offsite Dose Calculation Manual Changes Changes in the Sequoyah Nuclear Plant ODCM are described in this section in accordance with Sequoyah Technical Specification 6.14.2.

t These changes were officially approved by RARC on February 22, 1983. See Appendix A at the end of this report for the approved ODCM changes.

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OPERATING DATA FIPCRT ,

6 DCO IT te. 50-2:7 '

l DATE ffRIL 5,1?93

CCP!LETED SY h.0.EDDIf05 TELEFHONE (615)S70-6543 CFERATING STATlfi

1. UNIT hAME: EECtWa NUCLEAR FLfhT, LHIT 1 NOTES:

2. REF0;T PERICO: WFCH 1,1983 Mff:CH 21,1993 ,

1 3. LICENGED T6st FO.ERWT): 2411.0 ,

4. resLATE FATIhG 6:;053 NE): 1220.6  ;

j 5. CE h SN ELECTRIC /c FATING (hET MWE): 1143.0 j i 6. M4IPfJM DEfiNDABLE CiPiCITY MROSS NE): 1163.0

7. Airt*. CEFENDAPLE CF/CITi (NET Mia: 112?.0

8. IF chaff.-ES DCCL9 IN C// ACITY FAT!NOS(ITE*3 !?fiERS 3 THR W54 7)SIfn LA5i EtPORT. GIVE FIA50Ni'

9. FGE; LEtEL TO WICH FESTRICTED,IF (M(hEi tSO: . ,

j ___._____ . _ _ _ _ _ _

i 10. FEAiONS F0o FI51MCTIONS,lF AW: l f

I THIE ENTH YR.-TO-DATE CLT.ATI\E

11. W.id53 THEc?ti ENERGY COERATED U2) 2422535.99 6?66826.07 19021426.51

17. R ]SS ELECTE! Cit ENE M I (8 . ( NH) 840220.00 2272 6 0.00 H55250.09

10. NET ELECTRICfL ENEM ENERf,1ED UMH) 910143.00 22si270.00 6215530.60

19. UNIT EEEVICE FACTOR 100.00 97.50 81.!2 20 U5!T fNa!LABILIT! FfCTOR 100.00 97.50 81.12

21. UNI) CflACITY FACTORtLSING MDC tit) 96.57 93.95 75.51

22. Lh!T Cif ACITY QCTOR(USING DER fET) 94.29 92.?2 74.20

23. UNIT F0ctED CUTf6E RATE 0.00 2.20 12.17 21 HGCCU6 SCF Rin PVER hrXI 6 MONTHS (TVFE, EATF.

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Refuelingfmodification outage to begin(WD RFATION on approximate Oc ETEH)ly kugust Of983 for approximate 1~y-~90'Tays.

25. !F EHjiD M AT END OF FEPORT PERIOD. ESTIMATED DATE OF STreTLP:

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?.0TE THAT THE tee )R.-10-Ef4TE AND Cttttf4TIVE VfMS HAVE EEEN LFDATED.

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UNIT SHUTDOWNS AND POWER REDUCTIONS DOCKET NO. 50-328 UNIT NAME seouoyah Two DATE April 3, 1983 COMPLETED BY David Dupree REPORT MONTH March,1983 TELEPHONE (613) s/u-ba43 W

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, @g  % c p tj Licensee y Cause & Corrective No. Date t$

8, 8 '8 t 2 Event $% 8% Action to y 2S 2 5y* Report # g'g oi Prevent Recurrence 5" Ed$ N* 8" e "

7 83/03/07 F 0 A 5 Manual runback to 73%. All #3 H.D.T. pumps tripped. Lo-Lo level switch shorted.

8 83/03/12 F 0 B 5 Reduced load to 32%. Add oil to #2 R.C.P.

9 83/03/30 F 0 B 5 Incore/excore calibration. Reactor at 75%.

1 2 3 4 F: Forced Reason: Method:

S: Scheduled Exhibit G-Instructions A-Equipment Failure (Explain) 1-Manual for Preparation of Data-B-Maintenance or Test 2-Manual Scram. Entry Sheets for Licensee C-Refueling 3-Automatic Scram. Event Report (LER) File (NUREG-D-Regulatory Restriction 4-Cont. of Existing 0161) i E-Operator Training & License Examination Outage F-Administrative 5-Reduction G-Operational Error (Explain) 9-Other 5 (9/77) H-Other (Explain) Exhibit I-Same Source i

Picnt Maintenanca Summary The following significant maintenance items were completed during the month of March 1983:

Mechanical Maintenance

1. Changed out the 1A vacuum pump.

2. Installed ductwork to the #3 heater drain tank' motors.

3. Disassembled the boric acid transfer pump to replace the casing.

4. Changed out reactor coolant filter.

5. Installed a rupture disk in boric acid evaporator "A".

6. Changed out the UHI rupture disk.

7. Replaced drain papers in Unit 1 ice condenser bays #3 and #4.

8. Excavating- the hypochlorite line to the new ERCW station for trouble-shooting.

Electrical Maintenance

1. Continued installation of the Dimension 2000 phone system.

2. Continued systematic walk down and inspection of the E-field wiring and made necessary repairs.

3. Continued repairs on paging system to fulfill INPO commitment.

4. Replaced the motor on Unit 2 steam generator blow down pump.

5. Inspected Unit 1 pressurizer heater control banks.

6. Disassembled the RCP spare motor.

7. Functionally checked undervoltage coil operation on the Unit I and Unit 2 reactor trip bypass breakers A and B.

8. Performed functional check of the Unit 2 system 6 level switches.

9. Inspected 0-FCV-67-67 control circuit.

10. Added oil to Unit 1 RCP motors.

11. Checked the CRDM and RPI connector on Unit I reactor head, disassembled and checked connectors on P4 and D14 RPI's.

12 .' Checked RTD's on Unit 1 RCP motors.

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AVERAGE DAILY UNIT POWER LEVEL DOCKET NO. 50-328 UNIT Two DATE March, 1983 COMPLETED BY David Dupree TELEPHONE (615) 870-6543 MONTH March, 1983 DAY AVERAGE DAILY POWER LEVEL DAY AVERAGE DAILY POWER LEVEL (NWe-Net) (HWe-Net) 1 1123 17 1096 2 1122 18 1120 3 1122 19 1122 4 860 20 1122 5 1123 21 1123 l

6 1124 22 1123 7 801 23 1122 8 1072 24 1121 9 1120 25 1119-10 1121 26 1120 11 1121 27 1122 12 875 28 1124-13 1106 29 1122 14 1121 30 1092 15 1122 31 869 16 3i97 INSTRUCTIONS On this format, list the average daily unit power level in MWe-Net for each day in the reporting month. Compute to the nearest whole megawatt.

.(9/77)

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Elcetrical Mainten:nce (Continued) l l

13. Inspected B CSST.6.9 kV bus connections to start board.

14. Repaired filter network on Unit 2 hydrogen recombiner.

Instrument Maintenance

1. Performed a special test on Unit 1 solid state protection system input circuit due to a possible undetectable failure that could have existed.

This caused a reactor trip when some unused logic associated with the reactor coolant pump breakcrs was actuated when a ground path was com-pleted through the test equipment being used. Unit 2 was not tested.

2. Unit 1 NIS source range channel N-31 failed high. This required Mode 5 and replacement of the detector. The channel was recalibrated and returned i to service within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. I l

3. Recalibrated linit I and 2 UHI level switches using the new procedure. Found three out of four switches out of cal on Unit I and four out of four on Unit 2 ouc of cal. One engineer from Westinghouse and two from McGuire Nuclear Plant observed the calibration on Unit 2. Westinghouse has submitted a new evaluation to relax the tolerance on the setpoints. An evaluation is being done as to the possibility of replacing the switches with a different type.

4. Discussed reactor trip breaker response times with NRC and committed to test both units at the next available outage. This was in response to an inci-dent at Salem Nuclear Plant.

5. Removed status monitoring system internals for installation of the tech support center computer.

6. Changed out the Unit I gross failed fuel detector, recalibrated the instru-ment and returned to service.

I Field Services Group

1. ECNs 2780/5200--Post-Accident Sampling Facility (Units 1 and 2)

The instal'1ation of coduit and junction boxes is continuing on elevation 706 and elevation 714 in-the auxiliary building. Core drilling in the auxiliary building along the A-5 line wall is in progress and prefabrica-tion of HVAC ductwork is continuing. Fabrication and installation of supports is in progress. Tubing tie-on for solenoid valves was compleed for Unit 1. Installation of tubing from the solenoid valves to the panels in PASF Room is in progress. Panels were set into the PASF Room of Unit 2.

Demineralized water and component cooling water. piping are being installed for the Unit 2 PASF.

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. Field S2rviccs Graup (Continued)

2. ECN 5429--Containment Hydrogen Mitigation System (Unit 2)

Cable pulling and termination of igniters in the done of Unit 2 as well as post modification testing of the igniter circuits were completed.

Fabrication of seismic supports is continuing with approximately 10%

complete.-

3. -ECN 5009--ERCW Piping Changeout (Units 1 and 2)

Pre-fabrication of stainless steel piping for penetration room coolers'2A2 and 2B2 on elevation 690 was completed this month. Fabrication of piping 3 for penetration room coolers 2A1 and 2B1 on elevation 669 is in progress with work about 5% complete.

4. ECN 5417--Diesel Generator Air Start System Dryers This ECN is complete with the exception of an FCR to add mufflers to the air dryers. Mufflers have been ordered and scheduled for delivery in May 1983.

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5. ECN 5451--Diesel Generator Engine Lube Oil System All work has been completed with the exception of the functional testing

, of the pumps and pressure switches. This should be complete without the next reporting period.

6. ECN 5106--Reactor Vessel Level Indication System (Units 1 and 2)

Conduit and hanger installation in the auxiliary building is continuing.

Conduit and hanger installation is'in progress in the annulus of Unit 1.

Conduit and hangers are being installed on elevation 685, 701, and 732 of the control building. Cable pulling will begin in the near future.

7. ECN 5580--Plant Emergency Evacuation System Sirens

! All work has been completed on this ECN. -

i 8. ECN 2456--Seismically (!ualify H,, Lines In Auxiliary Building To i

Maintain Pressure Boundary During An SEE IJ No. 338 (Units 1 and 2)

I.

i This ECN entails replacing existing deadload-type pipe supports. To i date, 17 supports are complete (including painting) out of a total of approximately 60.

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9. ECN 5198--Locate and Design A Technical Support Center Conduit and hangers for the new lighting fixtures have been installed and the installation of the HVAC ductwork has been completed. The fire protection sprinkler system has been installed and sufficient work

, has been completed to allow outside contractor to begin the ceiling installation in April.

Field Services Grcup (Continued)

10. ECN 5460--Reroute Auxiliary Feedwater Pump Seal Water Plant (Units 1 and 2)

During this reporting period, the installation of hangers and drain lines for reroute of seal leakage from the auxiliary feedwater pumps continued for Unit I with work being approximately 90% complete.

11. ECN 5726--Reroute Feedwater Flow Sense Lines (Units 1 and 2)

Painting of Unit 2 hangers continued. No other work was performed during this period.

12. ECN 5119--Radiation Monitors For Containment Isolation Waste Disposal System (Unit 1)

Installation of conduit and cable pulling has begun on this ECN. Core drilling for sleeves is in progress.

13. ECN 2773--Instalatien of Radiation Detectors - Unit 2 The instalation of conduit and ha.gers was completed in the Unit 2 spreading room. QA has inspected the work in the auxiliary building, spreading room and the annulus.

14. ECN 2923--RHR Lines Radiation Monitors - Unit 2 The installation of con'duit and hangers in the Unit 2 spreading room to panels M-30 and M-31 was completed. Cable pulling is in progress for the RHR pump room radiation monitors.

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APPENDIX A i

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.I DOCUMENTATION FOR ODCM CHANGES I

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' APPENDIX A v

Change 1 Pages affected: 19 and 20 '!

Description of Change: Factor for estimating dilution ~credit in diffuser o ..

pond is increased from 2.4 x 10 " to 9.9 x 108 Analysis or Evaluation Incorporation of a more recent analysis of flow Justifying Change: experiments at the Sequoyah Nuclear Plant (SQN) diffuser pond.

Evaluation of Accuracy The change will have no impact on dose calculations, of Dose Calculation or but will increase the accuracy of set point deter-Setpoint Determination minations. ,

Change 2 s<

Pages affected: I and 14 '

Description of-Change: References to licensing meterology are deleted from the ODCM. j -

Analysis or' Evaluation 'It was noticed that the meterological datatused for Justifying _ Change: ODCM calculations are'not from.the same time p'eriod as those used in the Final. Safety Analysis Repo'rt.

The ODCM data .are from a 'mo're' recent time period.

It is believed that the ODCM data are more appro-priate, based on review of 1972-1980 data; there-fore, the references to licensing data were deleted and the data. retained.

Evaluation of Accuracy No impact on dose calculations.or set point determina- 1 of Dose Calculation or tions.

Setpoint Determination Change 3

Page affected

2 Description of Change: The assumed midpoint for the highest wind speed category is decreased from 13.00 to 110.95. ,

Analysis or Evaluation Most observations in the upper wind speed category

Justifying Change are actually just over the cutoff of 110.95.

1 Evaluation of Accuracy Any impact should be very sligbr due to theLcompara-of Dose Calculation or tively small number of.bigh _ wind speed observations.

Setpoint Determination However, the new values'willlbe more accurate for dose calculations and set pahit determinations.

Change 4 Pages affected: 2, 14, and 20 Description of Change: Typographical errors corrected. -

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1. - Gaseous Effluents ,

1.1.-Alarm / Trip Setpoints-Specification 3.11.2.1 requires that the dose rate in unrestricted areas due to gaseous effluents from the site shall be limited at all times to the following values:

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1. 500 mrem /y to the total body and 3,000 mrem /y to the skin from noble gases.

i 2. 1,500 mrem /y to any organ from radiciodines and particulates.

Specification 3.3.3.10 requires gaseous ef fluent monitors to have alarm / trip setpoints to ensure that the above dose rates are not exceeded. This section of the 01)CM describes the methodology that will be used to determine these setpoints.

,'x The methodology for determining-alarm / trip setpoints is divided into two major parts. The first consists of backcalculating' from a dose rate to a release rate limit, in Ci/s, for each nuclide and release point. The'second consists of us.ing the release rate limits to determine the. physical settings on the monitors.

1.1.1 Release Rate I.imit Methodology - pci/s Step 1 The-first step involves calculating a dose rate based on the design objective source term mix used in the licensing of the plant. Doses are determined for (1) noble gases and (2) iodines and particulates. 6 Depending on the pathway involved, either air concentrations or

- ground concentrations are calculated.

A. Equations and assumptions for calculating doses from noble gases are as follows:

Assumptions:

1. Doses to be calculated a,re total body and skin.

2. Exposure pathway is submersion within a cloud of noble gases.

3. Noble gas radionuclide mix is based on the design objective source term given in Table 1.1.

4. Basic radionuclide data are given in Table 1.2.

5. All releases are treated as ground level.

6. Meteorological data' arc expressed as a joint-frequency distribution of wind speed, wind direction, and atmospheric ,

stability for the period January 1972 to December 1975 (Table 1.3).

Revision 6 d

1

7. Raw-meteorological data consist of wind speed and direction measurements at 10m and temperature measurements at 9m and 46m.

8. Dose is to be~ evaluated at t he of fsi te exposure point where maximum concentrations are expected to exist.

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9. Pot ential maximum-exposure point s (Table 1.4) considered are the nearest site boundary points in each-sector.

10. A semi-infinite clo'id model is used.

11. No'eredit is taken for shielding by residence.

12. plume depletion and radioactive decay are considered.

13. Building wake ef fects on ef fluent dispersion 'are considered.

14. A sector-average dispersion equation is used.

15. The wind speed classes that are used are as follows:

Number Range (m/s) Midpoint (m/s) 1 <0.3 0.13 I 2 0.3-0.6 0.45 3 0.7-1.5 1.10 4 1.6-2.4 1.99 6

5 2.5-3.3 2.88 6 3.4-5.5 4.'45 7 5.6-8.2 6.91 8 8.3-10.9 9.59 5

, 9 '10.9

> 10.95

16. The stability classes that will be used are the standard A through G classi fications. The stability classes 1-7 will correspond to A=1, B=2, . . ., G=7.

17. Terrain ef fects are not considered.

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18. Environment al transfer dat a is consistent with NUREG/CR-1004.

Equations To calculate the dose for any one of the 16 potential maximum-exposure points, the following equations are used.

4 For determining the air concentration of any radionuclide:

I Revision 6 I

For determining the beta dose to air:

Dp n

='t m x ni

. DFD . i. (1.17) 'l2 i

where:

Dp = beta dose to air for sector n, mrad.

n X .

= air concentration of radionuelide i in sector n, "1

pCi/m 3 p

DFD*. = betaa to air dose fact or for radionuclide i, mrad /yr per pCi/m t, = time period considered, yr The sector having the highest total dose is then used to check compliance with specification 3.11.2.2.

1.2.2 Iodines and Particulates Step 1

~ Doses will be calculated using the methodology described in this step.

I f any limits are exceeded, step 2 will be performed.

Equations and assumptions for calculating doses from releases of iodines and particulates are as follows:

Assumptions

1. Doses are to be calculated for the infant . thyroid from milk ingest ion and for the child bone from vegetable ingestion.

2. Real cow locations are considered for the milk pathway and nearest resident-locations with home-use gardens are considered for the vegetable pathway.

3. The highest annual-average D/Q based on 1972 to 1975 meteorologica1'

data for ground level releases will be used for 1-131 and Sr-90 doses. 3 1

4. No credit is taken for radioactive decay. T

5. Releases of I-131 are considered for the milk pathway.

I Sr-90 releases are considered for the vegetable pathway.

6. The calculations extrapolate doses assuming that only 90 percent 5 of the total dose was contributed.

l 7. The cow is assumed to graze on pasture grass for the whole year.

4 l

Revision 6 L

e The results, from field tests conducted in September 1979, are expressed ini terms of relative concent ration r:

r'= 9.9x10~5 '(F + fg & f3 & f 3

E6)

Equations 2.3 then becomes ,

2-9.9x10 5 (F + f t_

+f 2

+f 3 + E4) II (R1 -1) + f2 (R2 -1) + f3

~

(R 3 ~I)

• I (R4 4 -1) i F (2.3a) 2.2 Instrument setpoints 2.2.1 Setpoint Det erminat ion The setpoint for each liqui.d ef fluent monitor will be established using plant instructions. Concentration, f l ow ra t e , dilution, principal gamma emitter, geometry, and detector efficiency are combined to give an equivalent setpoint in counts per minute (cpm).

The physical and technical description location and identification number for each liquid effluent radiation detector is contained in plant documentation.

The respective alarm / trip setpoints at each release point will be set such that the sum of the ratios at each point, as calculated by Equation 2.2, will not be exceeded. The R is directly related to the total concentration calculated by Equadion 2.1. An increase in-the concentration would indicate an increase in the respective R .

A large increase would cause the limitsspecifiedinSection2.lllto be exceeded. The minimum alarm / trip setpoint value is equal to the release concentration, but for ease of operation it may be desired that the setpoint(s) be set above the effluent concentration -(C ) .

That- is, 3 S. = b. x C. (2.4)

J J J or

-S.-

b. = J-J -C.

J where

S. = desired alarm / trip setpoint at release point J.

J b.

~

= scaling factor to prevent alarms / trips due-to J variations in the effluent concentrations at release point- j.

C. = total concentration in the liquid effluent at release J point j speci fied by Equation 2.1, pCi/ml .

Revision 6

The R. used in Equation 2.3a must also be scaled by the corresponding scaleffactor. Equation 2.3 anil the corresponding . alarm / trip setpoints 2 become 9.9x10 5 (F + f y +f-2 +f

- 3 +I4) f1 (b3 _Ry -1) +

f. 2 (b 7 R2 ~I) + f3 (b 3 N 3 -I) + I4 I 4 R4 -1) .1 F (2.5) 3 S

by =1 (2.6)

C 1

S b =

2 C

(2.7) 2 S

b -=3 (2.8) 3 L,3 3

b 4

=4 _

(2.9)

C 4

For example, for 2 release points , minimum dilution flow and no difruser pond dilution this becomes, fy (St x Rt )-1 +f 2 (82xR) 2 -1

<15,000 (2.10)

_k _ _2C 2.2.2 Post-Release Analysis A post-release analysis will be done using actual release data to ensure that the limits specified in Section 2.1.1 were not exceeded.

A composite list of concentrations (C;), by isotope, will be used

, with the actual. liquid radwaste (f) a6d dilution (F) flow rates-(or volumes) during the release. The data will be substituted into L

Equation 2.~3 to demonstrate compliance with the limits in Section

'2.1.1. This data and setpoints will be recorded in auditable records  !

by plant personnel.

l 2.3 Dose s._

2.3.1 RETS Requirements i

t Speci ficat ion 3.11 '. l .2 o f t he Radiological Ef fluent Technical Specification (RETS) requires that the dose or dose commitment to an individual from radioactive materials in 1iquid effluents released to unrestricted areas from each reactor (see Figure 2.2.1-1) shall be limited:

a. During any calendar quarter to 11.5 mrem to the total body and to i

l 15 mrem to any organ, and l

l l Revision 6 u.- f%%g

. ~.

1 0

.h i

TENNESSEE VALLEY AUTHORITY Sequoyah Nuclear Plant P. O. Box 2000 Daisy, Tennessee 37319 APR 141983 Nuclear Regulatory Commission Office of Management Information and Program Control Washington, DC 20555 Gentlemen: -

Enclosed is the March 1983 Monthly Operating Report for Sequoyah Nuclear Plant.

Very truly yours, TENNESSEE VALLEY AUTHORITY

1. C. C. Mason

) Power Plant Superintendent Enclosure cc (Enclosure):

Director, Region II Director, Office of Management Director, Office of Management Information and Program Control Nuclear Regulatory Commission Nuclear Regulatory Commission 101 Marietta Street Washington, DC 20555 (2 copies)

Suite 3100 Atlanta, GA 30303 (1 copy)

Director, Office of Inspection and Enforcement Nuclear Regulatory Commission Washington, DC 20555 (10 copies)

Mr. A. Rubio, Director Mr. Bill Lavallee, NSAC

! Electric Power Research Institute P. O. Box 10412 Palo Alto, CA 94304 (1 copy) l Mr. R. C. Goodspeed MNC 461 Westinghouse Electric Corporation P. O Box 355 Pittsburgh, PA 15230 (1 copy)

//

An Equal Opportunity Employer

/ . - , _ . . . . . - . _ , . . _ , . - . . . __ - . - , _ , .