ML20092H128

Evaluation of Sequoyah Nuclear Plant Offsite Dose Calculation Manual,Rev 28

ML20092H128
Person / Time
Site:	Sequoyah
Issue date:	08/31/1995
From:	Akers D, Menke L IDAHO NATIONAL ENGINEERING & ENVIRONMENTAL LABORATORY
To:	NRC (Affiliation Not Assigned)
Shared Package
ML20092H099	List: ML20092H128
References
CON-FIN-E-2084 INEL-95-0375, INEL-95-375, NUDOCS 9509200271
Download: ML20092H128 (26)

Text

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INEL 95/0375 f,

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l August 1995 l

Idaho j

l National Engineering Evaluation of Sequoyah Nuclear Plant i Laboratoy Offsite Dose Calculation Manual, Revision 28 i

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j Docket No. 50-327, Facility License No. DPR-77 l

Docket No. 50-328, Facility License No. DPR-79

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. L. H. Menke l D. W. Akers i

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WLocWieed idaho Technologies Company l

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PDR ADOCK 05000327 l P PDR

INEL 95/0375 Evaluation Of Sequoyah Nuclear Plant Offsite Dose Calculation Manual, Revision 28 NRC DOCKET NO. 50-327 NRC LICENSE NO. DPR-77

! NRC DOCKET NO. 50-328 NRC LICENSE NO. DPR-79 I

L. H. Menke D. W. Akers l

Published August 1995 t

4 idaho National Engineering Laboratory i Locheed Martin Idaho Technologies

', Idaho Falls, Idaho 83415 t

i Prepared for the Division of Radiation Safety and Safeguards Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission i Washington, D. C. 20555 Under DOE Contract No. DEA-ACO7-761D01570 FIN No. E2084 l

INEL 95/0375 ABSTRACT The Offsite Dose Calculation Manual (ODCM) for the Sequoyah Nuclear Plant (SQN) OCDM con-tains (1) current methodology and parameters used to calculate offsite doses, dose rates, effluent monitor-ing alarm setpoints, (2) the radioactive effluent / radiological environmental monitoring controls and surveillance requirements, and their bases, and (3) the radiological environmental monitoring program.

'Ihe NRC transmitted the most recent complete SQN ODCM, Revision 28 effective December 1,1992, to the Idaho National Engineering Laboratory for review by EG&G Idaho, Inc. The ODCM was reviewed by EG&G, and the results are presented in this report.

The SQN ODCM ' generally uses documented and approved methods that are consistent with the methodology and guidance of NUREG-0133 and Regulatory Guide 1.109. The ODCM contains at least a verbal description of all the required methodology. Four primary comments on monitoring methodology, calculational methods for liquid effluent releases, and total dose calculation methods were identified and should be addressed promptly. Due to several omissions and errors found in the ODCM, it is recom-mended that the ODCM be revised to address and correct the most significant deficiencies identified in the review.

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INEL 95/0375 FOREWORD

'This report is submitted as partial fulfillment of the " Review of Radiological Issues" project being conducted by the Idaho National Engineering Laboratory for the U. S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation. The U. S. Nuclear Regulatory Commission funded this work un-der FIN E2084.

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warrant, expressed or implied, or assumes any legal liability or responsibility for any third party's use, or the results of such use, or of any information, apparatus, product or process disclosed in this report, or represents that its use by such third party would not infringe privately owned rights.

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INEL 95/0375 1 1

. 1 CONTENTS ABSTRACT................................................................................................................ii j FOREWORD....................................,....................................................................iii i FIGURES..............................................................................................................iv TABLES...........................................................................................................................iv AC R ON YM S/S YM B OLS . . .. . . . .. . . .. . . . . . .. .. .. .. . . ... . . . . . .. . . ... . .. . . ..... .. . .. . . .. . ... . .. . . .. .. . . ... . . . .. . . ... . .. . . v

1. I NT R O D U CTI O N . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I 1.1 Purpose Of R e vie w .. . . .. .... .. . . .. . . . . .. .. .. . . . . . . . .. . . . . .. . . .. .. . . .. ... . . . . .. .. . . . . . . .. . . . . . . . . . . . . . . . . . . I 1.2 Plan t S pecific B ackground . .. ....:... .. .. .. .. .. . . .. ....... .... ..... .. .. .. . ... .. .. .. ..'..... . .. .. .. .... . .... 3

2. R EV I EW C RITE RI A . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . 4

3. R ADIOACTIVE EFFLUENT RELEASE ROUTES ............ ...... ... . ... ... ... .................. 5 l 3.1 Liquid Effluent Release Routes ..... ........... ....................... .... . ..... .... .... ............ 5

4. E V A L U ATI O N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1 Liquid Effluent Monitor Setpoints . ... ... . ... ...... .................... ..... ............13  :

4.2 Gaseous Effluent Monitor Setpoints .... .... . . ..... . .............. ............. .. .. . ......... 14 l 4.3 Concentrations In Liquid Effluents .............. ........ .... .............. ..................... ....... 15 '

l 4.4 Dose Rates Duc To Gaseous Effluents ......................... . .......................... ............ 16 4.4.1 Dose Rates Due To Noble Gases ........................... ................................. 16 4.4.2 Radionuclides Other Than Noble Gases ... ........ .. ......... ........................ 16 4.5 Dose Due To Liq uid Effluents ... .. .. . . . .. .. .. .. .. .... ............ .. . . ... .... . .. .. .. . .... .. ...... ..... .. 16 4.6 Dose Due To G aseous EfH uents .. .. .. .... .. .... .. .. .. .. .. .. .. .... .. . .... .. .... .. ..... .. .. .. .. ...... .... 17 4.7 D ose Projections .. . . . . . . .. .. .. .. . . . . . . . . . . . . .. . . . . . . . .. . . . . . . . . . .. .. . . . . . . . . . . . . . .. . .. . . . . . . .. . . .. .. . . . . .. .. .. .. .' 19 4.7.1 Liquid Effluent Dose Projections............. .... ..... ............. .......... .......... 19 4.7.2 Gaseous Ef0uent Dose Projections ....... ........ .... . ..... .... ... ................ . 19 4.8 Diagrams Of EfDuent Release Routes ..................................... .............. ............... 19 .

l 4.9 To tal D o se . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.10 Environmental Monitoring Program .. .... .. .. ...................... . ..... .................... . 20 l 4.1 I Interlaboratory Comparison Program .... ......... .. ............. .................. .. ....... .. 20

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SUMMARY

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6. C O N C L U S I O N S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .l 7 . R EFE R EN C E S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . .;

FIGURES

1. Liq uid e ffluen t release routes at S QN. ....... ............... ....... ............ .......... ... . .. ... ............... 6

2. Liq u id rad was te s ys tem at S Q N. . . .. . . . . . . . . . . . . .. . . . . . . . . . . .. .. . . . . . . . . .. . . . . . .. . . . . . . . . . .. .. . . .. . . . . . . . . . . . . . . . . . . . 7

3. Steam Generator Blowdown Units 1 & 2 and the Condensate Demineralizer System at SQN...........................................................................................................................8 1

4. Gaseous effluent release routes at SQN (based on Figure 7,1 of the SQN ODCM R e vis i o n 2 8 . ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5. Gaseous radwaste and off-gas treatment system at SQN. ......................... ......... ............... I 1 TABLES

1. S um m ary o f SQN ODC M, Revision 28. ............. ...................... ........... ............ ... . . .. .. . 2

2. Liquid efnuent Gow rates and storage capacity at SQN. ... . ............... ........... ...... ... .... .. 9

3. G aseo us e ffl ue n t flo w rates . . .. .. . . .. . . .. .. . . . . . .. . . .. .. . . . . . . . . .. . . . . .. .. . . . .. .. .. . . . . . . . . .. . . . . . . . . . .. . . .. .. .. . . . . . 12

4. Liquid release point dilution flow and fraction of dilution flow, A . ...... .. .. ........... .. . .. 14

5. A ge g ro u p de scri p tio n. . . . . .. . . . . .. .. . . . . . . . . . . . . . . . . . .. . . . . . . . . . . .. . . . . . . . .. . . . . . . .. . .. . . . . . . . . . . . .. . . . . . . . . . . . . 17 IV

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ACRONYMS / SYMBOLS D Symbol used for radiation induced doses D Symbol used for radiation dose rates CFR Code of Federal Regulations CSR Control and Surveillance Requirements FR Federal Regulation INEL Idaho National Engineering Laboratory NRC Nuclear Regulatory Commission ODCM Offsite Dose Calculation Manual RETS Radiological Effluent Technical Specifications

( SQN Sequoyah Nuclear Plant TRM Tennessee River Mile

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INEL 95/0375 Evaluation Of Sequoyah Nuclear Plant (SQN) Offsite Dose Calculation Manual, Revision 28

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1. INTRODUCTION 1.1 Purpose Of Review This document reports the review and evaluation of the most recent version of the Offsite Dose Calculation Manual (ODCM) submitted by the Tennessee Valley Authority, the Licensee for the Sequoyah Nuclear Plant (SQN). Revision 28 of the ODCM, effective December 1,1992, was transmitted to EG&G Idaho for review. The ODCM is a supplementary document used to implement the Radiological Effluent Technical Specifications (RETS) for compliance with 10 CFR 50, Appendix I.3 This review of this document was performed to assess conformance of the ODCM to the SQN technical specification and NRC guidelines. The ODCM is divided into two major parts.

The first part of the ODCM contains the control and surveillance requirements (CSRs) required by the

, SQN Technical Specifications, including:

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1. Radioactive Effinent Controls required by Section 6.8.5.f of the SQN Technical Specification.

2. Radiological Environmental Monitoring Controls required by in Section 6.8.5.g of the SQN Technical Specifications.

3. Description of the information that should be included in the Annual Radiological Environmental and Semiannual Radioactive Efiluent Release Reports required by SQN Technical Specification 6.9.1.6 and 6.9.1.8.

4. Administrative Controls for the ODCM requirements.

The second part of the ODCM contains the methodologies used to:

1. Calculate offsite doses resulting from radioactive gaseous and liquid effluents.

2. Calculate gaseous and liquid effluent monitor Alarmffrip setpoints.

3. Conduct the Environmental Radiological monitoring Program.

The SQN ODCM will be maintained for use as a reference guide on accepted methodologies and cal-culations. Changes in the calculation methods or parameters are incorporated into the ODCM to assure that the ODCM represents the current methodology in all applicable areas. Any licensee initiated ODCM change will be implemented in accordance with SQN technical Specification 6.1.4 and ODCM Administrative Control 5.3. A summary of SQN ODCM, Revision 28 is listed in Table 1.

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INEL 95/0375 T(ale 1. Summary of SQN ODCM, Revision 28.

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Procedural Tech. Spec.

Implementadonin Detailsin Programmatic ODCM Section ODCM Control Section Brief Description of Contents J

1.0, 2.0 None None Purpose and scope of the ODCM 1.1.1 Section 6.2 6.8.5.f.1 Liquid effluent monitoring instrumentation and surveillance 1.1.1 Section 6.2 6.8.5.f.1 Liquid setpoint determination 1.2.1.1 Section 6.1 6.8.5.f.2. Liquid effluent concentration f l None None 6.8.5.f.3 l' 2.2.1.1.1 None None Liquid sampling and analysis l.2.1.2 Section 6.3 6.8.5.f.4, Liquid effluent dose commitment j 6.8.5.f.4 -)

2.2.1.3 Section 6.5 6.8.5 f.6 Liquid radwaste treatment and dose projection l.1.2 Section 7.1 6.8.5.f.1 Gaseous effluent monitoring

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instrumentation and surveillance

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-None Section 7.1 6.8.5.f.1 Gaseous setpoint determination 1 1.2.2.1 Section 7.2.3 6.8.5.f.7 Gaseous effluent air dose rate (noble gases) 1 1.2.2.1 Section 7.2.4 6.8.5.f.7 Gaseous organ dose rate (iodines, tritium, )

and particulates) 2.2.2.1.2 None 6.8.5.f.9 Gaseous sampling and analysis i 1.2.2.2 Section 7.6 6.8.5.f.4 Gaseous air dose commitment l J 1.2.2.3 Section 7.6.3 6.8.5.f.4 - Gaseous organ dose commitment i 1.2.2.4 Section 7.5 6.8.5.f.8 Gaseous radwaste treatment and dose projections 1.2.3 Section 6.3,7.3, 6.8.5.f.10 Uranium fuel cycle (total) dose 7.4 1.3.1 Section 9.0 6.8.5.g.1 Radiological environmental monitoring, sampling, and analysis None Section 7.8 None X/Q and D/Q methodology and data I 1.3.2 Section 5.1 6.8.5.g.2 Land use census l.3.3 Section 5.1 6.8.5.g.3 Interlaboratory Comparison Program 4

6.9.1.8 Section 5.2 6.15.1.1 Major changes to liquid and gaseous radwaste treatment systems j None Section 5.1 6.9.1.6 Annual Radiological Environmental j Operating Report None Section 5.2 6.9.1.8 Semiannual Radioactive Effluent Release Report None Section 5.3 6.14 Changes to the ODCM 1

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INEL 95/0375 1.2 Plant Specific Background The plant site, consisting of approximately $25 acres, is located in Southeastern Tennesec on the

West shore of Chickamauga Lake, approximately 9.5 miles Northeast of Chattanooga.

The population density of the area surrounding the site is relatively low with only three cities within 30 miles of the plant having populations exceeding 10,000 people. The minimum exclusion and low population distances are 1,824 ft and 3 mile, respectively.

SQN consists of two Westinghouse pressurized water reactors rated at i148 MW(e) SQN Unit 1 started .,ommercial operation July 1,1981 and SQN Unit 2 started commercial operation June 1,1982.

A complete site description with identifications of bodies of water, rivers, agriculture, population, and recreational activities that are within the vicinity of SQN, has not been included in the ODCM. For review purposes, this information was obtained from the Final Safety Analysis Report. A description of geographical features that would affect gaseous effluent distributions and the corresponding shielding factors should be included in the ODCM.

A brief site description should be included in the ODCM even if one is available in other SQN doc-uments. This site description should include, as a minimum, the nearest population locations that may be affected by effluent releases, rivers and bodies of water that may receive liquid effluents, agriculture ac-tivities, and recreational activities.

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INEL 95/0375

2. REVIEW CRITERIA Review criteria for the ODCM were provided by the NRC in two documents

1. NUREG-1302 Offsite Dose Calculation Manual Guidance: Standard Radiological Effluent Controls for Pressurized Reactors.2,

2. NUREG-0133. Preparation of Radiological Effluent Technical Specifications for Nuclear Power Plants.3 .

The following NRC guidelines were also used in the ODCM review:

1. Regulatory Guide 1.109, Revision 1. Calculation of Annual Doses to Man from Routine Releases of Reactor Effluents for the Purpose of Evaluaang Compliance with 10 CFR 50, Appendix I.4

2. Branch Technical Position, General Contents of the Offsite Dose Calculation Manual (ODCM).5 As specified in NUREG-1302, the ODCM is to be developed by the licensee to document the methodology and approaches used to calculate offsite doses and maintain the operability of the radioac-tive effluent systems. As a minimum, the ODCM should provide equations and methodology for the fol-lowing:

Alarm and trip setpoints on effluent instrumentation

• Liquid effluent concentrations in unrestricted areas

+ Gaseous effluent dose rates at or beyond the site boundary

+ Liquid and gaseous effluent dose contributions

• Liquid and gaseous effluent dose projections

. The NRC regulations require that the ODCM be a stand alone document.

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INEL 95/0375

3. RADIOACTIVE EFFLUENT RELEASE ROUTES Liquid and gaseous effluent release routes from SQN are discussed in this section, along with the monitoring methodology currently being used. The description in Revision 28 of the ODCM dated September 25,1992, was reviewed. Comments on the clarity of the description of the monitoring methodology and the adequacy of the monitored release routes are included in this section.

3.1 Liquid Effluent Release Routes There are five liquid effluent release sources at SQN. Rey are the liquid radwaste system, the con-densate demineralizer system, the turbine building sump, the steam generator blowdown for Units 1 and 2, and essential raw cooling water effluent header. A simplified diagram of the five sources is shown in Figure 1. Figure 2 provides additforial details on the Liquid Radwaste System while Figure 3 provides additional details on the condensate demineralizer system and the steam generator blowdown. ..-~ -,

Radioactive liquid effluents from all liquid effluent sources except the turbine building pump are discharged into the cooling tower blowdo.wn line. From the blowdpyvgline this is dscharged to the diffuser pond for ultimate discharge to the Tennessee river. The turbine building pumps are discharged directly to the diffusion pond. The cooling tower blowdown provides dilution for liquid effluents at a minimum flow rate of 15,000 gpm. De circulating water intake and outlet are both in the Tennessee River. SQN CSR 1.1.1 requires radioactivity monitors with alarm setpoints on the following effluent - .

lines:

• Liquid Radwaste Effluent Line.

• Steam Generator Blowdown Effluent Line.

• Condensate Demineralizer Regenerant.

= Essential Raw Water Cooling Water Effluent Header.

• Turbine Building Sump Effluent Line. l i

it is important to note that a complete listing of monitors are samplers is not included in Table 1.1-1. l 0-RM-90-211, which monitors the inlet to the diffuser pond,is not listed in Table 1.1-1 or ODCM Figure  ;

i 6.1 and there is no required operability requirement. This monitor should monitor the cooling tower blowdown discharge. Further, there is no evidence of a monitor on the diffuser pond outlet, which would i monitor possible concentration factors in the diffuser pond. Also, it is recommended that the flow rates l for each liquid discharge point be included in a figure or tablular form. Table 2 lists the flow rates and storage capacity of tanks for five effluent liquid pathways. In ODCM Figure 6.1, a reference is made to ,

ODCM Figure 2.2; it should refer to ODCM Figure 6.2  !

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4 INEL 95/0375 Condensate Turbine Demineralizer Building l System Sump

mm Steam Generator i ~ Blowdown p , .y,, . ,

Unit 1 l Yard Low Volume Pond Waste Treatment Steam Generator Blowdown Unit 2

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Liquid Radwaste Diffuser System Pond l

J l JL r---____q l l l I l Routine Path D Pathway j l l g during L low river U l l 7 110w I I I y -

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Cooling Tower Blowdown l'

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I (Minimum 15,000 gpm for dilution) l pCS Rive /r L A 4 W

! Raw Cooling I

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Water Flow l

L _ _____J Figure 1. Liquid effluent release routes at SQN. (Based on Figure 6.1 of the SQN ODCM Revision 28.)

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lNEL 95/0375 Condensate Reactor m Tritiated Dram.

Building Drains Collector Tank

--> Demineralizer Waste Evaporator h

Auxiliary Vendor

- Floor Drain '

Radwaste Buildm, g " '

Collector Tank System Drams h

20 gpm Chemical Drain Tank -> Monitor Tank <

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, 600 gal + (22,000) gal 4[ 125 gpm V

~ Waste Distillate Tanks (8,500) gal Laundry and Hot + Cask Decon Shower Tanks x 2 _, Collector Tank 4 (15,0(X)) gal 125 gpm 50 gpm 600 gal each 20gpm I

Routine Release Path y Cooling Tower Blowdown Figure 2. Liquid radwaste system at SQN. (Based on Figure 6.2 of the SQN ODCM Revision 28.)

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l S/G S/G T/C S/G l S/G S/G S/G S/G

1. l # # #4 l

_#_1 _#2_ _ 3_ _#4_

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l l I I 80 gpm per S/G l 80 gpm per S/G l l lf lf l If lf S/G Draindown SGBD  ! S/G Draindown SGBD  !

! Flash Tank H/X  ! Flash Tank. H/X g _

g I I I I I I V I y l l l Cooling Tower Blowdown l Cooling Tower Blowdown l l__ l_

Steam Generator Blowdown Unit 1 Steam Generator Blowdown Unit 2 F

High Crud l 180 gpm l l Tank 1 (20,000 gal) l c l

! o j U l l High Crud Tank 2 l 180 gpm f!

l (20,000 gal) l 1 o g

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• g"d l Neutralization 180 gpm o l

Tuk Tw l l (19,000 gal) on w  !

Non-Reclaimable l 180gpm l I

l Waste Tank (l1,000 gal) l l

_ ______J Condensate Demineralizer System KEY:

S/G Steam Generator H/X Heat Exchangers SGBD Steam Generator Blowdown '

Figure 3. Steam Generator Blowdown Units 1 & 2 and the Condensate Demineralizer System at SQN.

(Based on Figure 6.1 of the SQN ODCM Revision 28.) i 8

INEL 95/0375 Table 2. Liquid effluent flow rates and storage capacity at SQN.

Storage Release Point Flow Rate (gpm) Capacityrrank (gal)

Liquid Radwaste System Chemical drain tank 20 600 Laundry and hot shower tanks (2) 20 600 Monitor tank -

125 22,000 Cask decon collector tank 125 15,000 Waste distillate tanks 50 8,500 360 47,300 Condensate demineralizer system Illgh crud tank (2) 180 20,000 Neutralization tank 180 19,000 Non-reclaimable waste tank 180 11,000 720 70,000 Turbine building sump 1,500 30,000 Steam generator blowdown (2) N/A N/A Essential raw water cooling header N/A N/A 3.2 Gaseous Effluent Release Routes ,

4 Bere are six vents at SQN that are monitored for airborne effluents as required by CSR 1.1.2. They I are:

Condenser vacuum exhaust for each unit (2).

• Service building exhaust.

• Auxiliary building exhaust.

• Shield building exhaust for each unit (2).

A simplified diagram of the six exhaust points is shown in Figure 4. Figure 5 shows the gaseous radwaste treatment system, which is also monitored as noted in CSR 1.1.2.

Regulatory Guide 1.109, Revision 1, Section c.2 specifies that for elevated gaseous releases, the height of the release points should be specified in making estimates of average effluent concentrations downwind from the release points. Vent sizes, exit velocities, and/or flow rates should be specified in the ODCM along with height of surrounding buildings. If gaseous release is at ground level , Regulatory Guide 1.1116 specified that building wake conection terms be used. Shape factors and building cross sections should be specified. in the ODCM.

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INEL 95/0375 4

Plant Vents A h JL h i

CVE Unit 1 S B U nit 1 SB AB CVE Unit 2 SB Unit 2

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I CVE Condenser Vacuum Exhaust Vent SB Service Building Vent d

AB Auxiliary Building Vent SB Shield Building Vent l Figure 4. Gaseous effluent release routes at SQN (based on Figure 7.1 of the SQN ODCM Revision 28.)

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INEL 95/0375 i-CVCS VCT Unit 1 -

j CVCS VCT Unit 2 CVCS HT lumme A 4 L RCDT Unit 1 Waste Gas

> > Compressor Package x 2 RCDT Unit 2 -

Plant Vent 6 w mmmm i CVCS EVAPS I m n 4

CVCS HT ' Y (3rN (y 3 6y 3

< J J J Waste Gas Waste Gas e Ta k Decay Tank 7 Decay Tanks (providing (being filled) cover gas) (isolated)

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r 3 ( h ( 3 l  % J < J < J l KEY:

CVCS Chemical and Volume Control System VCT Volume Control Tank RCDT Reactor Coolant Drain Tank EVAPS Evaporators l HT Holdup Tank i

Figure 5. Gaseous radwaste and off-gas treatment system at SQN. (Based on Figure 7.3 of the SQN ODCM Revision 28.)

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INEL 95/0375 l As noted, there are six monitored exhausts at SQN; however, the ODCM suggests that there are un-monitored release points. This should be clarified and a description of the unmonitored release points should be made if they exists along with their flowrates. Each release path should be identified with ac-tual flowrates and simplified diagrams. In addition to simplified diagrams showing the gaseous effluent release points, it is recommended that the flow rates for each gaseous discharge point be included in a figure or tabular form. Table 3 lists the flow rates for the six moni:ared gaseous effluent points.

Table 3. Gaseous effluent flow rates, i

Release Point Flow Rate (cfm)

(2) Condenser vacuum exhaust 45 Service building vent 14,950 General building exhaust 228,000 (2) Shield building vent >28,000 I

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INEL 95/0375

4. EVALUATION The SQN ODCM is a supporting document for the SQN Technical Specifications. The ODCM should be a stand-alone document and it should include a detailed presentation of the calculational models used, including a complete tabulation of all values assigned to each parameter used in the calculations.

Two changes to the ODCM which would facilitate referencing and discussion would be the use of stan-dard notation for mathematical symbols, and use of a consistent equation numbering system.

4.1 Liquid Effluent Monitor Setpoints CSR 1.1.1 requires that the radioactive liquid effluent monitoring instrumentation channels shall be OPERABLE with their alarm / trip setpoints set to ensure that the limits of CSR 1.2.1.1 are not exceeded.

The alarm / trip setpoints of these channels shall be determined in accordance with the methodology and parameters in ODCM Section 6.2.

The methodologies listed in ODCM Section 6, Liquid Releases, to calculate setpoints are generally ,

correct. Ilowever,it should be noted that the flowrates on page 64 for the tanks in the condensate dem-  !

ineralizer system are different than those specified in Figure 6.1. This discrepancy should be addressed.

Specific comments are stated below: ,

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• In Section 6.2.1, the discharge monitor setpoints for monitor 0-RE-90-211 are discussed; how- I ever, this monitor is not included in Table 1.1-1. Also, no monitoring appears to be performed at J. the outlet of the diffuser pond. Justification should be provided for not providing appropriate monitoring, control, and surveillance requirements for the outlet of the diffuser pond.

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• The last paragraph of ODCM Section 6.2.2," Release Point Monitor Setpoints," states that con-1 tinuous release monitors are set in the same fashion as the batch release monitors. It is not clear that this technique, when calculated over a one-week period provides conservative monitor set-points for continuous releases because the sum of the fractions method used in Section 6.2.3 does not identify these release path'vays and no specific dilution flow is allocated to these pathways.

These equations should be clar.ified.

+ In ODCM Section 6.1.2,"MPC-Sum of the Ratios," the term MPC, maximum permissible con-centration is not defined. The term MPC should be defined when used even though it may be common terminology.

• In ODCM Section 6.2.3, " Batch Release Point Monitor Setpoint," Equation 6.4 lists a safety fac-tor, Sr, for the monitor. The ODCM does not contam any numerical values for the safety factor.

The safety factor presumably is a conservative factor that is less than one. If the safety factor is greater than one, then the potential exist for larger effluent releases. The ODCM should include the definition and numerical examples of the safety factor. The NRC requires that the ODCM contain sample calculations. The ODCM should include sample setpoint calculations.

In ODCM Section 6.2.3, " Batch Release Point Monitor Setpoint," an administrative factor, X", is discussed. This administrative factor , which may be the safety factor, Sr, is designed to account for expected variations in monitor response. It is not obvious what this administrative factor is.

The logic of using the administrative factor would be better stated as follows:

S=XxSe where S = actual setpoint 13

d INEL 95/0375 ,

i Sg = expected monitor response setpoint X = administrative factor ,

l he ODCM states that the administrative will be defined in approved plant instructions. The l administrative factor should be defined in the ODCM with example values for completeness.  ;

• In Equation 6.4 of ODCM Section 6.2.3," Batch Release Point Monitor Setpoint," the fraction of dilution How allocated to a release point, A,is defined. It is recommended that the fraction of di-lution flow allocated to a release point, A, be tabulated. An example is listed in Table 4. Also, releases from the liquid radwaste , and/or condensate dendneralizer system should be addressed.

Table 4. Liquid release point dilution flow and fraction of dilution flow, A..

Release Point Minimum Flow Dilution Factora Rate (gpm)

Radwaste 9,000 0.6

! Condensate Demineralizer 3,000 0.2 ,

Steam Generator Blowdown (Unit 1) 1,500 0.1 l Steam Generator Blowdown (Unit 2) 1,500 0.1 a Based on a total flow rate of 15,000 gpm.

It is also recommended that the dilution fraction be subscripted, i.e., A,. Where w is the release point.

To be within NRC guidelines, the methodology to determine setpoints for the liquid effluent monitors should include the method used to prevent simultaneous releases from more than one batch release tank.

This section would be better illustrated if a table of liquid effluent setpoint locations, setpoint identifica-tion and setpoint limits in numerical or symbolic form is included. He SQN ODCM does not indicate if the liquid alarm and the automatic control trip are separate devices. If they are, the alarm / trip setpoint in the ODCM should list the separate trip setpoints. He alarm setpoints should be lower than the automatic control setpoints. Separate calculations for both should be included in the ODCM.

4.2 Gaseous Effluent Monitor Setpoints In accordance with CSR 1.1.2, the radioactive gaseous effluent monitoring instrumentation channels shown in ODCM Table 1.1-2 shall be OPERABLE with their alarm / trip setpoints set to ensure that the limits of ODCM Control 1.2.2.1 are not exceeded. De alarm / trip setpoints of these channels shall be de-termined in accordance with the methodology and parameters in ODCM Section 7.1.

The methodologies listed in ODCM Section 7 are generally correct; however, there are some items that require further clarification. As noted previously, it is not clear from page 102 that all potential gaseous release points are monitored. Bis should be clarified, or the lack of monitors should be justified.

Other changes or subjects for which clarification is required are discussed below.

- ODCM Section 7.1.1.1, " Containment Purge Efiluent Monitors," states that the monitor setpoint is set at a percentage of an SQN Technical Specification limit. The percentage used and its basis should be stated.

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. in ODCM Section 7.1.1.2," Waste Gas Decay Tank Effluent Monitor," the monitor setpoint for the release is set equal to X times the expected monitor response. The administrative factor,X,is designed to account for expected variations in the monitor response. This section states that the administrative factor, X, is defined in approved plant instruction. 'Ihe administrative factor also j needs to be defined in the ODCM. The values used for the administrative factor and its justifica- l tion need to be included in the ODCM.

+ In ODCM section 7.1.1.2, " Waste Gas Decay Tank Eftluent Monitor," Equation 7.2 identifies a dose rate allocation factor A and a safety factor Sj:. To properly evaluate the methodology, these factors should be listed and sample calculations presented. j

- ODCM Section 7.1.2, " Discharge Point Monitor Setpoints," describes in words the mathematical determination of setpoints. This can be clearly illustrated in the following manner:

If(XSg < Sp) & (So < Smax) then S = So If (XSg > Sp)II(So > Smax) then S = XSg The following notation is used to describe this logic.

Symbol Description Sm,, Calculated maximum setpoint S Actual setpoint determined in logic diagram Sp Normal default setpoint Sg Expected monitor response X Administrative factor

& Logical AND l Logical OR SQN ODCM does not indicate if the gaseous alarm and the automatic control trip are separate de-vices. If they are, the alarm / trip setpoint in the ODCM should list the alarm and trip setpoints separately.

4.3 Concentrations in Liquid Effluents ,

1 in accordance with SQN Technical Specincation 6.8.5.f.2 and 3 and CSR 2.2.1.2, the concentration of l radioactive material released to UNRESTRICTED AREAS shall be limited to the concentrations speci- )

fled in 10 CFR Part 20, Appendix B Table II, Column 2 for radionuclides other than dissolved or en-trained noble gases. For dissolved or entrained noble gases, the concentration shall be limited to 2 x 10" mircocuries/mi total activity.

There is no ODCM section which describes the calculation of concentrations ofliquid elfluents that may be released into water ways. This calculation should include as a minimum, what bodies of water re-ceive liquid effluents, the range of the total dilution flow and the maximum dilution flow rate for the Cooling Tower Blowdown. ODCM Section 6.3," Cumulative Liquid Effluent Dose Calculations," covers some of the required liquid concentration calculations. This section defines a near field average dilution factor, D. The calculation of D uses a mixing factor defined as the percentage of the river flow that is available for dilution of the release. The method used to develop this factor, D, should be presented. In addition, the general methods used to calculate liquid effluent doses should be better defined, and exam-pies and/or references to other relevant sections used to calculate dose should be included in the ODCM.

In ODCM Section 6.2," Instrument Setpoints," no maximum dilution flow rate for the cooling tower blowdown is defined. Based upon NUREG-0133 cooling tower blowdown times an applicable factor is limited to 1000 cfs. The range of the total dilution flow, TDF, should be identified. It is recommended 15 1

l l

INEL 95/0375 that the following statement be made;"The very large dilution factors afforded by the circulating coolant  ;

will not be used to allow high concentrations of liquid radioactive waste to be discharged from the plant."

4.4 Dose Rates Due To Gaseous Effluents In accordance with SQN Technical Specification 6.8.5.f.7, the dose rate due to radioactive materials released in gaseous effluents to areas at or beyond the SITE BOUNDARY shall be limited to the follow-ing:

a For noble gases: b s 500 mrem /yr to the total body and b $ 3,000 mrem /yr to the skin.

+ For 3'i, 333 1, 3H, and for all radionuclides in particulate form with half-lives greater than 8 days:

b s 1,500 mrem /yr to any organ.

1 Example calculations of the expected dose rates that a member of the public at or beyond the site I boundary may receive should be shown in Section 7.2 with all factors defined. i 4.4.1 Dose Rates Due To Noble Gases Pursuant to SQN Technical Specification 6.8.5.f.7, Control 1.2.2.1 requires that dose rates due to ra-dioactive noble gases released in gaseous effluents be limited to less than or equal to 500 mrem /yr to the whole body and to less than or equal to 300() mrem /yr to the skin. ODCM Section 7.2, " Gaseous Efiluents - Dose Rates," contains methodology to determine that dose rates at or beyond the site boundary due to releases of radioactive noble gases in gaseous effluents are within the limits of ODCM Section 1/2.2.2, " Gaseous Effluents."

The licensee's methmlology to determine dose rates due to radioactive noble gases is within NRC guidelines. However, in order to clarify how the equations ;ue used, the licensee should include example calculations of the expected dose rates due to noble gases that a member of the public at or beyond the site boundary may receive.

4.4.2 Radionuclides Other Than Noble Gases Pursuant to SQN Technical Specification 6.8.5.f.7 and CSR 1.2.2.1 requires that dose rates due to ra-dioactive other than noble gases released in gaseous effluents be limited to less than or equal to 1,500 mrem /yr to any organ for all radionuclides in particulate form with half-lives greater than 8 days. ODCM Section 7.2, " Gaseous Effluents - Dose Rates," contains methodology to determine that dose rates at or 3

beyond the site boundary due to release-s of I, 8331 , 3H, and all radionuclides in particulate form with half-lives greater than 8 days in gaseous effluents are within the limits of ODCM Section 1/2.2.2

" Gaseous Efiluents."

The licensee's methodology to determine dose rates due to radioactive other than noble gases is within NRC guidelines. However, the licensee should include example calculations.

4.5 Dose Due To Liquid Effluents In accordance with SQN Technical Specification 6.8.5.f.4 and 5, and CSR 1.2.1.2, the dose or dose commitment to a member of the oublic from radioactive materials in liquid eftluents released to unt.c:

stricted areas shall be limited from each reactor unit to:

During any calendar quaner During any calendar yea; D $ 1.5 mrem to the total body D s 3 mrem to the total hmiy 16

l' l lNEL 95/0375 l'

! D $ 5 mrem to any organ D 510 mrem to any organ ODCM Sections 6.6 and 6.7 contain the methodology used to determine the cumulative dose contribu-tions from liquid efiluents for the current calendar quarter and current calendar year.

ODCM Section 6.3, " Cumulative Liquid Effluent Dose Calculations," lists the age groups and organs i

that are used in dose and dose rate calculations. De age groups should specify the age ranges or whether the dose commitment age is used. The equations in Regulatory Guide 1.109 use the dose commitment 1

age. His is described on page 1 Section 1 of Regulatory Guide 1.109. It is recommended that this data be summarized in tabular form as shown in Table 5.

Table 5. Age group description.

Fraction of population 3

Dose commitment a, POP,in each age Age group a Years of age (yr) age (yr) group Infant 0-1 Newborn = 0 0.015

Child 1 11 4 0.16.8 Teen 11-17 14 0.153 Adult 17 4 17 0.665 3

a NUREG/CR-1004, Table 3.39 i

t The ODCM description of dose factor equations should start with the defining equation and with all terms defined. Een a description of the special cases for water ingestion, aquatic food ingestion, and shoreline recreation should be included. His would make the description more clear. ]

The equations in Section 6.7, " Liquid Dose Factor Equations," should be labeled. I 4.6 Dose Due To Gaseous Effluents In accordance with SQN Technical Specification 6.8.5.f.8 and CSR 1.2.1.2, the air dose due to noble gases released in gaseous efiluents from each reactor unit to area at or beyond the site boundary shall be limited top the following:

During any calendar quarter During any calendar year D $ 5 mrem for gamma radiation D 510 mrem for gamma radiation D s 10 mrem for beta radiation D $ 20 mrem for beta radiation It is recommended that the data related to the variables in ODCM Section 7.6.4, Population Doses, be summarized in tabular form. This would improve the appearance of the document. l i

ne following paragraphs pertain to the gaseous dose pathway factors R((X/Q] or R((D/Q).

• ODCM Section 7.7.1, " Pasture. Grass-cow / goat-milk Ingestion Dose Factors," the equation for the l milk dose factor is not labeled and should be numbered. l

• ODCM Section 7.7.2," Stored Feed-cow / goat-milk Ingestion Dose Factors," the equation for the feed dose facter should be labeled. Also, the reference to this equation is unclear. It should be shown where this equation is referenced in the document.

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+ ODCM Section 7.7.3, " Pasture Grass-beef Ingestion Dose Factors," the equadon for the beef dose factor should be labeled and numbered.

+ ODCM Section 7.7.4, " Stored Feed-beef Ingestion Dose Factors," the equation for the stored beef dose factor should be referenced and numbered.

+ ODCM Section 7.7.5, " Fresh Leafy Vegetable Ingestion Dose Factors," the equation for the fresh vegetable dose factor should be labeled and numbered.

+ ODCM Section 7.7.6, " Stored Vegetable Ingestion Dose Factors " the equation for the stored vegetable dose factor should be labeled and numbered.

+ ODCM Section 7.7.7, " Tritium Pasture Grass-cow / goat milk Dose Factors," the equation for the tritium dose factor should be labeled and numbered. This equation is modified from the equation in NUREG-0133. These modifications should be modified.

- ODCM Section 7.7.8, " Tritium Stored Feed-cow / milk Dose Factors," the equation for the tritium dose factor should be labeled and numbered.

• ODCM Section 7.7.9," Pasture Grass-beef Dose Factors," the equation for the tritium dose factor should be labeled and numbered. This equation appears to be a modification of the equation in NUREG-0133, Section 5.3.1.4. The modification should be justified.

• ODCM Section 7.7.10. " Tritium Stored Feed-beef Dose Factors," the equation for the tritium dose factor should be labeled and numbered.

+ ODCM Section 7.7.11, " Fresh Leafy Vegetables Dose Factors," the equation for the tritium dose factor should be labeled and numbered. This equation appears to be a modification of the equa-tion in NUREG-0133, Section 5.3.1.5. De modificadon should be justified.

+ ODCM Section 7.7.12, " Tritium Stored Vegetables Dose Factors," the equation for the tritium dose factor should be labeled and numbered. This equation appears to be a modification of the equation in NUREG-0133, Section 5.3.1.5. The modification should be justified.

• ODCM Section 7.7.14, " Ground Plane Dose Factors," the equation for the ground dose factor should be labeled and numbered. Also, the equation leaves out the sitielding factor Sr. compared to NUREG-0133, Section 5.3.1.2. This modification should be justified.

ODCM Table 7.5, " Population Within Each Sector Element," does not indicate the time period that the population data was taken. De year that this data was determined should be specified in the table or table capdon.

+

ODCM Figure 7.4, " Plume Depletion Effect For Ground Level Releases," the vertical axis label

" Fraction Remaining in Plume" should read "p Fraction Of Radionuclide Remaining In plume."

v ODCM Figure 7.5, " Vertical Standard Deviation Of Material In A Plume," has the following un-defined labels, A-G. Figures should have all labels described. Define the vertical axis symbol a t. His definition can be included in the figure caption. For example, a is the vertical disper-sion coefficient.

I8

INEL 95/0375 4.7 Dose Projections In accordance with CSR 2.2.1.2 and 2.2.2.4, dose projections will be performed. Riis will be done by maintaining running 31-day totals for the gamma , beta, and muimum organ dose.

4.7.1 Liquid Effluent Dose Projections ODCM Section 6.5, " Dose Projections," indicates that the average of the previous two months doses will be used to project doses for the next 31 days. It is clear that this is a conservative estimate that would prevent the limits in ODCM Control 1.2.1.2 fr6m being exceeded. The dose projection calculations need to be explicit and example calculations need to be presented along with a table of the radwaste dilution factors noted on the equations.

4.7.2 Gaseous Effluent Dose Projections Section 7.5 of the ODCM indicates that 31-day running totals will be used to project doses from the off-gas systems; however, no method is indicated for projected the doses as was done for the liquid dose projections. Blis should be clarified and methods should be presented for projecting the doses from gaseous effluents along with example calculations.

4.8 Diagrams Of Effluent Release Routes

'The ODCM contains five diagrams related to radioactive effluent treatment and release routes.

However, the diagrams are difficult to read, rely on un-keyed abbreviations. This does not meet the NRC recommendation that the ODCM contain " simplified flow diagrams defining the treatment paths and the components of the radioactive liquid and gaseous waste management systems."

To be consistent with NRC guidelines, the licensee should replace the present figures with appropri-ate simplified flow diagrams. Detailed comment of each figure follows.

- ODCM Figure 6.1, Liquid Effluent Release Points, should be simplified. An example of the pos-sible simplification is illustrated in Figure 1 of this report of Sequoyah 1/2 ODCM. If more detail is desired by the licensee, use a separate figure for each major radioactive gaseous release point.

Figures 2 and 3 of the Technical Review of Sequoyah 1/2 ODCM illustrate breaking up ODCM Figure 6.1 into several simpler illustrations.

• ODCM Figure 7.1," Gaseous Effluent Release Points," should be simplified. Add a symbol / term key. An example of the possible simplification is illustrated in Figure 4 of the Technical Review of Sequoyah 1/2 ODCM, If more detail is desired by the licensee, use a separate figure for each major radioactive gaseous release point.

• ODCM Figure 7.2," Auxiliary And Shield Building Vents," should be simplified. Add a sym-bol/ term key, An example of the possible simplification is illustrated in Figure 6 of the Technical Review of Sequoyah 1/2 ODCM. If more detail is desired by the licensee, use a separate figure for each major radioactive gaseous release point.

+ ODCM Figure 7.3," Gaseous Radwaste Treatment System," should be simplified. Add a sym-bol/ term key. An example of the possible simplification is illustrated in Figure 5 of the Technical Review of Sequoyah 1/2 ODCM. If more detailis desired by the licensee, use a separate figure for each major radioactive gaseous release point.

19

. I INEL 95/0375 4.9 Total Dose In accordance with SQN Technical Specification 6.8.5 f.10, the annual (calendar year) dose or dose commitment to any member of the public, due to releases of radioactivity from uranium fuel cycle sources, shall be limited to less than or equal to 25 mrem to the total body or any organ (except the thy-roid, which shall be limited to less than or equal to 75 mrem).

• ODCM Section 8.1, " Annual Maximum Individual Doses-Total Reported Dose " contains a ver-bal description of annual dose methodology. NRC guidelines require that the total dose method-ology include the mathematical formulation of the total dose components, for example see Regulatory Guide 1.109, the final total dose expressions, and examples of the expected total dose under expected plant operation. The mathematical description of the total dose methodology should be included in the ODCM.

- ODCM Section 6.6.4, " Total Maximum Individual Dose," contains a verbal description of the total maximum individual dose from liquid effluents. This verbal description should be aug-mented with an mathematical description of the methodologies. This section could be included in the Total Dose Section.

4.10 Environmental Monitoring Program In accordance with SQN Technical Specification 6.8.5.g.1 and CSR 9.0,the radiological environmen-tal monitoring program shall be conducted as specified in ODCM Table 2.3-1. The Radiological Environmental Monitoring Program measures radiation and radioactive material exposure pathways that lead to the highest potential radiation exposure of members of the,public resulting from plant operation.

This monitoring program implementsSection IV.B.2 of Appendix I to 10 CFR Pan 50. The Radiological Environmental Monitoring Program is within NRC guidelines.

It is recommended that Figure 9.1, " Environmental Monitoring Locations Within One Mile Of ne j Plant," indicate that the numbers represent labeled environmental monitoring locations. It is recom- i l

mended that Figure 9.2, " Environmental Monitoring Locations From One To Five Miles From The Plant," indicate that the numbers represent labeled environmental monitoring locations and that the con-centric rings have a distance marker. It is recommended that Figure 9.3," Environmental Monitoring Locations Greater han Five Miles From he Plant," have a key that states that the numbers represent la-beled environmental monitoring locations and that the concentric rings have a distance marker. l It is recommended that Table 9.1, " Environmental Radiological Monitoring Program Sampling l l

Locations," and Table 9.2 "Thermoluminescent Dosimetry Locations," specify the center location from which the radial distance is measured.

4.11 Interlaboratory Comparison Program In accordance with SQN Technical Specification 6.8.5.g.3 and CSR 1.3.2, analysis shall be performed on radioactive materials supplied as part of an Interlaboratory Comparison Program which has been ap- i proved by the Commission.

ODCM Section 9.4, "Interlaboratory Comparison Program," decribes the licensee's Interlaboratory Comparison Program. The Interlaboratory Comparison Program is within NRC guidelines. l l

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INEL 95/0375

5.

SUMMARY

Primary deficiencies and suggestions are summarized below in four categories of decreasing impor-tance. He items in Category A identify the most series deficiencies, including omissions that cause un-certainty about whether the proper methodology is used in the ODCM. Catege'y B contains deficiencies that are less series than Category A, and Category C contains minor deficiencies and editorial recommen-dations. Category D contains suggestions for changes the licensee may wish to make to simplify calcula-tions, update data, or remove excess conservatism from the methodology.

Category A:

The items in this category should be addressed promptly. Some items identify errors or emissions that result in erroneous calculated doses and dose rates. Others identify omissions or inappropriate values that may result in release rate limits being exceeded or reported doses being insufficiently documented.

1. The justi!1 cation for not including the RM-90-211 monitor for the inlet to the diffuser in the oper-ability requirements should be discussed along with the reason for not monitoring the outlet of the diffuser pond where some radionuclide concentration mat occur. RM-90-21I should be in the table and at the diffuser pond outlet.

2. The ODCM is outside the NRC guidelines, because it does not include a section on the calcula-tion of concentrations in liquid effluents. This section should include as a minimum, what bodies of water receive liquid effluents, the range of the total dilution flow and the maximum dilution flow rate for the Cooling Tower Blowdown. Methods that are referenced in NRC Regulatory Guide 1.109, Revision 1 or other sources should be included in the ODCM.

l 3. The possibility of simultaneously having batch and continuous releases of radioactive liquid I

effluent is not discussed. If simultaneous batch releases are possible, the appropriate equations and calculations should be included in the ODCM.

4. ODCM Section 8.1, " Annual Maximum Individual Doses-Total Reponed Dose," contains a ver-bal description of annual dose methodology. The total dose methodology should include the l mathematical formulation of the total dose components, for example see Regulatory Guide 1.109,

the final total dose expressions, and examples of the expected total dose under expected plant op-I eradon.

Category B:

l The items below concern information that should be added to make the ODCM complete, prevent erroneous interpretation of the methodology, or correct methodology that is erroneous.

1. It is recommended that each major section (for example, liquid and gaseous setpoints, gaseous l dose rates, liquid and gaseous doses, and dose projections) include an example calculation. Rese examples should illustrate plant specific values.

2. There is no site or plant description concerning bodies of water, river, agriculture, population, and recreational activities are within the vicinity of SQN. It recommended that a brief description of the nuclear unit along with geog;aphical features that would effect gaseous effluent distributions and the corresponding shielding factors. De site description should include one or more dia-grams.

3. For gaseous releases from stacks, the height of the stack should be specified in the ODCM. Are the stacks greater than 80 meters or at ground level (meaning less than 80 m, see Regulatory 21

o i INEL 95/0375 Guide 1.109). The atmospheric dispersion factors are dependent on the height of the release point. This should be clearly stated in the appropriate section in the ODCM. In addition, the height of surrounding buildings should be listed.

4. The ODCM should specify how liquid release setpoint calculations are affected by the release type.

5. SQN ODCM does not indicate if the alarm and the automatic control trip are separate devices. If they are, the alarm / trip setpoint in the ODCM should list the separate trip setpoints.

6. ODCM Section 7.1.1.1, " Containment Purge Effluent Monitors," states that the monitor setpoint is set at a percentage of a Technical Specification limit. This methodology should be described and tabulated.

7. In ODCM Section 7.1.1.2," Waste Gas Decay Tank Effluent Monitor," the monitor setpoint for the release is set equal to X times the expected monitor response. He administrative factor, X, is designed to account for expected variations in the monitor response. This section states that the administrative factor, X, is defined in approved plant instruction. The administrative factor should be defined in the ODCM along with a justification of the values listed.

8. In ODCM Section 6.2, " Instrument Setpoints," no maximum dilution flow rate for the cooling tower blowdown is defined. The range of the total dilution flow, TDF, should be identified. It is recommended that the following statement be made; "The very large dilution factors afforded by the circulating coolant will not be used to allow high concentrations of liquid radioactive waste to be discharged from the plant."

9. ODCM Section 6.5, " Dose Projections," second paragraph states that if the projected doses ex-ceed monthly limits, the liquid radwaste treatment system will be used to reduce the radioactive materials in liquid wastes prior to their discharge. The dose projection calculation should be ex-plicit. The dilution factor and the maximum rate or dilution and discharge should be clarified.

10. The ODCM should contain flow diagrams that represent plant systems and that define the treat-ment paths and the components of the liquid and gaseous management systems. A description and the location of samples in support of the environmental monitoring program are also needed in the ODCM.

I1. There are six monitored exhausts at SQN; however, the ODCM suggests that there are unmoni-tored release points. This should be clarified and a description of the unmonitored release points should be made if they exists along with their flowrates. Each release path should be identified with actual flowrates and simplilled diagrams. In addition to simplified diagrams showing the gaseous effluent release points, it is recommended that the flow rates for each gaseous discharge point be included in a figure or tabular form.

12. In ODCM Section 6.2.3," Batch Release Point Monitor Setpoint," Equation 6.4 lists a safety fac-tor, Sg, for the monitor. The ODCM does not contain any numerical values for the safety factor.

The safety factor presumably is a conscrvative factor that is less than one. If the safety factor is greater than one, then the potential exist for larger effluent releases. The ODCM should include the definition and numerical examples of the safety factor. The NRC requires that the ODCM contain sample calculations. The ODCM should include sample setpoint calculations.

13. In ODCM Section 6.2.3," Batch Release Point Monitor Setpoint," an administrative factor, X", is discussed. This administrative factor , which may be the safety factor, S7, is designed to account for expected variations in monitor response. It is not obvious what this administrative factor is.

22

INEL 95/0375 q The ODCM states that the administrative will be defined in approved plant instructions. The administrative factor should be defined in the ODCM with example values for completeness.

14. In Equation 6.4 of ODCM Section 6.2.3," Batch Release Point Monitor Setpoint," the fraction of dilution flow allocated to a release point, A,is defined. It is recommended that the fraction of di-lution flow allocated to a release point, A, be tabulated.

15. In ODCM section 7.1.1.2," Waste Gas Decay Tank Effluent Monitor," Equation 7.2 identifies a dose rate allocation factor A and a safety factor S. To properly evaluate the methodology, these factors should be listed and sample calculations presented.

16. ODCM Section 7.1.2, " Discharge Point Monitor Setpoints," describes in words the mathematical determination of setpoints.

17. The calculation of D uses a mixing factor defined as the percentage of the river flow that is avail-able for dilution of the release. The method used to develop this factor, D, should be presented.

In addition, the general methods used to calculate liquid effluent doses should be better defined, and examples and/or references to other relevant sections used to calculate dose should be in-cluded in the ODCM.

18. Example calculations on ." expected dose rates that a member of the public at or beyond the site boundary may receive should be shown in Section 7.2 with all factors defined.

19. ODCM Section 6.3," Cumulative Liquid Effluent Dose Calculations," lists the age groups and organs that are used in dose and dose rate calculations. The age groups should specify the age ranges or whether the dose commitment age is used. The equations in Regulatory Guide 1.109 use the dose commitment age. This is described on page 1 Section 1 of Regulatory Guide 1.109.

It is recommended that this data be summarized in tabular form as shown in Table 5.

20. The ODCM description of dose factor equations should start with the defining equation and with all terms defined. Then a description of the special cases for water ingestion, aquatic food inges-tion, and shoreline recreation should be included. This would make the description more clear.

21. Section 7.5 of the ODCM indicates that 31-day running totals will be used to project doses from i the off-gas systems; however, no method is indicated for projected the doses as was done for the liquid dose projections. This should be clarified and methods should be presented for projecting the doses from gaseous effluents along with example calculations.

Category C:

The items in this category indicate omissions and editorial deficiencies that are not likely to cause significant problems:

To improve readability, a consistent numbering system should be used for the equations.

Category D:

The following items concern methodology and parameters that the licensee may wish to change be-cause the change may simplify calculations, remove unnecessary conservatism in the calculations, or make use of recent data:

ODCM Section 7.1.2, Discharge Point Monitor Setpoints, describes in words the mathematical de-termination of setpoints. This can be clearly illustrated in a symbolic manner.

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INEL 95/0375

6. CONCLUSIONS Re licensee's ODCM, Revision 28 December 1992 generally uses documented and approved meth- l ods that are consistent with the methodology and guidance of NUREG-0133 and Regulatory Guide 1.109. 4 The ODCM contains at least a verbal description of all the required methodology. However, the SQN l ODCM should have a complete mathematical description of the methodologies, and example calculations )

for each calculational method should be in the ODCM. l 1

Due to several omissions and errors, it is recommended that the ODCM be revised to address and I

• I correct the most significant deficiencies identified in the review.

Primary areas in which additional clarification is needed are:

1. Justification for not including the RM 90-211 monitor for the inlet to the diffuser pond in the op-etability requirements should be discussed along with the reason for not monitoring the outlet of the diffuser pond where some radionuclide concentration may occur.

2. To be within NRC guidelines, the ODCM should include a section on the calculation of concen-trations in liquid effluent. His calculation should include, as a minimum, the bodies of water that receive liquid effluent, the range of the total dilution flow, and the maximum dilution flow rate for the cooling tower blowdown. Methods that are referenced in NRC Regulatory Guide 1.109 Revision 1, or other sources should be included in the ODCM.

3. The possibility of simultaneous batch releases of radioactive liquid effluent is not discussed. This should be clarified. if simultaneous batch releases are possible, the appropriate equations and J calculations should be included in the ODCM. l

4. ODCM Section 8.1, Annual Maximum Individual Doses-Total Reported Dose, contains a verbal description of annual dose methodology. The total dose methodology should include the mathe-matical formulation of the total dose components; for example, see Regulatory Guide 1.109, the final total dose expressions, and examples of the expected total dose under expected plant opera-tion.

t l

l l

)

i 24

INEL 95/0375

7. REFERENCES

1. Title 10, Code of Federal Regulations. Part 50, " Domestic Licensing of Production and Utilization Facilities"

2. NUREG-1302, "Offsite Dose Calculation Manual Guidance: Standard Radiological Effluent Controls for Pressurized Water Reactors ", Generic Letter 89-01, Supplement No.1, April 1991.

3. Standard Radiological Effluent Technical Specifications For Pressurized Water Reactors, NUREG.

0133, Revision 3,1988.

4. Regulatory Guide 1.109, Calculation Of Annual Doses To Man From Routine Releases Of Reactor Effluents For The Purpose Of E' valuating Compliance With 10 CFR Part 50, Appendix 1.

5. " General Contents of the Offsite Dose Calculation Manual", Revision 1, Branch Technical Position, Radiological Assessment Branch, NRC, February 8,1979.

6. Regulatory Guide 1.111," Methods For Estimating Atmospheric Transport And Dispersion Of Gaseous Effluents In Routine Releases From Light-Water-Coolder Reactors," Revision 1 July 1997.

l 1

4 25

o Mr. Oliver D. Kingsley, Jr.

SEQUOYAH NUCLEAR PLANT Tennessee Valley Authority cc:

Mr. O. J. Zeringue, Sr. Vice President TVA Representative .

Nuclear Operations 1

Tennessee Valley Authority l Tennessee Valley Authority 11921 Rockville Pike 3B Lookout Place Suite 402 1101 Market Street Rockville, MD 20852

, Chattanooga, TN 37402-2801 Regional Administrator i Dr. Mark 0. Medford, Vice President U.S. Nuclear Regulatory Commission Engineering & Technical Services Region II 4

Tennessee Valley Authority 101 Marietta Street, NW., Suite 2900 3B Lookout Place Atlanta, GA 30323 1101 Market Street

Chattanooga, TN 37402-2801 Mr. William E. Holland

Senior Resident Inspector

Mr. D. E. Nunn, Vice President Sequoyah Nuclear Plant New Plant Completion U.S. Nuclear Regulatory Commission

, Te.nnessee Valley Authority 2600 Igou Ferry Road

3B Lookout Place Soddy Daisy, TN 37379 l , 1101 Market Street i Chattanooga, TN 37402-2801 Mr. Michael H. Mobley, Director '

4 Division of Radiological Health

, Site Vice President 3rd Floor, L and C Annex -

Sequoyah Nuclear Plant 401 Church Street

! Tennessee Valley Authority Nashville, TN 37243-1532 4

P.O. Box 2000 Soddy Daisy, TN 37379 ' County Judge

' Hamilton County Courthouse  !

General Counsel Chattanooga, TN 37402-2801 Tennessee Valley Authority ET 11H 400 West Summit Hill Drive j Knoxville, TN 37902 Mr. P. P. Carier, Manager

Corporate Licensing Tennessee Valley Authority i

4G Blue Ridge i 1101 Market Street Chattanooga, TN 37402-2801 Mr. Ralph H. Shell Site Licensing Manager -

Sequoyah Nuclear Plant Tennessee Valley Authority P 0. Box 2000 Soddy Daisy, TN 37379 i

.