ML032541049

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Transmittal of Entire EAL Basis Document (Table of Contents Rev) (Copy 91)
ML032541049
Person / Time
Site: Duane Arnold NextEra Energy icon.png
Issue date: 08/29/2003
From:
Nuclear Management Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML032541049 (30)
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Text

- .:

Committed to NucMear Exce e DAEC EMERGENCY PLANNING DEPARTMENT PROCEDURE TRANSMITTAL ACKNOWLEDGEMENT MEMO (TAM-67)

To: NRC-NRR Document Control Desk US NRC Washington DC 20555 Re: Entire EAL Basis Document (Table of Contents Rev) (Copy 91)

PSM

Title:

n/a Distribution Date: 08 /29 /2003 Effective Date of Change: 08/29/2003 Retum by: 09112 2003 Please perform the following to your assigned manual. If you have any questions regarding this TAM please contact Don A. Johnson at 319-851-7872.

--- REMOVE INSERT EAL Table of Contents Revision Rev. 13 Rev. 14 EAL EBD-A (PWR: 21931) Rev. 5 Rev. 6 PERFORMED BY:

Print Name Sign Name Date Please return to: K Dunlap PSClEmergency Planning 3313 DAEC Rd.

Palo, IA 52324 To be completed by DAEC EP personnel only.

Date TAM retumed:

EPTools updated: _ #oy3'

NMCi Committed to NuclearExcellen9 Duane Arnold Energy Center Operated by Nuclear Management Company, LLC Friday, August 29, 2003 NRC-NRR Document Control Desk US NRC Washington, DC 20555 To: NRC-NRR Document Control Desk From: DAEC Emergency Planning Department Re: Description of changes to the following documents EAL EBD-A Abnornal Rad Levels/Radiological Effluent Category Change the EAL Bases Document, EBD-A to be consistent with the EAL Table, EAL-01 to allow usage of the table without continually refering to the EAL Bases Document. This change will enhance the timeliness of the EAL Declarations.

Add equipment IDs where ever they are missing to enhance TIMELY & ACCURATE EAL declarations.

Raise the Unusal Event entry setpolnt to 2 times the ODAM limit (CAP028632) for Offgas Stack and LLRPSF Kamans as shown In Bases Document table.

Please contact Paul Sullivan, Manager of Emergency Preparedness at DAEC, (319)851-7191, if you require further information.

nnfA nor R'nari _ Pain in1a d9flAQ7A

ALBASESDOC1J T =Rev. fil 14 INDEX Page 1 of I PROCEDURE TITLE REV # REV. DATE Introduction 1 210112000 Definitions 2 8/5/2003 Organization of Basis Information 3 8/5/2003 EBD-A Abnormal Rad Levels/Radiological Effluent 6 8/29/03 Category I EBD-F EBD-F Fission Product Barrier Degradation Category 3 1120200 3 1/020 EBD-H Hazards and Other Conditions Affecting 5 8/5/2003 EBD-H Plant Safety Category 5 8520 EBD-S System Malfunction Category 4 9/3012002 EBD-E ISFSI Abnormal Events Category 0 8/5/2003

F i I., II f " I EAL BASES DOCUMENT m , , ,,

EBD-A I : . . 1 I1 Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 1 of 27 Usage Level Reference Use Effective Date: I-a~v3 l

TECHNICAL REVIEW

~- ~ .~ 1j ' 2- '- :a. -' ': -. '

Prepared by:

OF,{

Date: -/2 .'/

Reviewed by: Date: ~'/?7 /o3 N. Inde nde t Reviewer Reviewed by: Date: zk3

(/ Operations Reviewer I am responsible for the technical content of this procedure and for obtaining the necessary approval from the State and County Emergency Management officials prior to implementation.

Documentation of State and County Emergency Management approval Isvia NEP-2003-0033.

Approved by. Date: 9-/'&/e 4aiiage, Emergency Planning

t AL BASES DOCUMENT EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 2 of 27 Table of Contents:

AU - Any Unplanned Release of Gaseous or Liquid Radioactivity to the Environment That Exceeds Two Times the Offsite Dose Assessment Manual (ODAM) and is Expected to Continue For 60 Minutes or Longer.A-3 AU2 - Unexpected Increase in Plant Radiation . A-8 AA - Any Unplanned Release of Gaseous or Liquid Radioactivity to the Environment that Exceeds 200 Times the Offsite Dose Assessment Manual (ODAM) and is Expected to Continue for 15 Minutes or Longer...,.-.'..A l................

1 AA2 - Major Damage to Irradiated Fuel or Loss of Water Level that Has or Will Result in the Uncovering of Irradiated Fuel Outside the Reactor Vessel .. ... A-16 AA3 - Release of Radioactive Material or lnt'feases in Radiation Levels Within the Facility That Impedes Operation of Systems Required to Maintain. Safe Operations or to Establish orto Maintain Cold Shutdown ..... - A-19 ASI - Site Boundary Dose Resulting from an Actual or Imminent Release of Gaseous Radioactivity Exceeds 100 mrem TEDE or 500 mrem CDE Thyroid for the Actual or Projected Duration of the Release ..................A-21 AG1 - Site Boundary Dose Resulting from an Actual or Imminent Release of Gaseous Radioactivity that Exceeds 1,000 mrem TEDE or 5,000 mrem CDE Thyroid for the Actual or Projected Duration of the Release .... A-24

EAL BASES DOCIUMENT-:: EIBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 3 of 27 AU1 Any Unplanned Release of Gaseous or Liquid Radioactivity to the Environment That Exceeds Two Times the Offsite Dose Assessment Manual (ODAM) Limit and is Epected to Continue For 60 Minutes or Longer EVENT TYPE: Offsite Rad Conditions OPERATING MODE APPLICABILITY: All EAL THRESHOLD VALUE: (1 or 2 or 3 or4), r-

1. Valid Reactor Building ventilation rad monitor (Kaman 3/4, 5/6 7/8) or Turbine Building ventilation rad monitor (Kaman 1/2) reading above 1 E-3 pCi/cc and is expected to continue for 60ominutes orlrger.:L.i. .s - -

OR - .. .M' tr!2 ' , I .

Valid Offgas Stack-rad monitor (Khiiian10)/l'Oreadink above 2.0 E-i pCi/cc and is expected to continue for 60 minutes?!oje.  !\.i i -it- D:

Valid LLRPSF rad monitor (Kaman -12)-ridiig abovet 1.0E-E-3 p i/cc and is expected to continue for 60 minutes or longer. . ......

OR .,. - v Valid GSW rad monitor (RIS4767) readiig above JEB CPS and is expected to continue for 60 minutes or longer. .- .1-,;-

OR Valid RHRSW & ESW rad monitor (RM19.7),radfig above 8E+2 CPS and is expected to continue for 60 minutes or longer.

OR Valid RHRSW & ESW Rupture Disc rad monitor (RM4268) reading above 1E+3 CPS and is expected to continue for 60 minutes or longer.

OR

2. Confirmed sample analyses for gaseous or liquid releases indicates concentrations or release rates in excess of 2 times ODAM limit and is expected to continue for 60 minutes or longer.

OR

3. Valid perimeter radiation monitor reading of greater than 0.10 mr/hr above normal background and is expected to continue for 60 minutes or longer.

OR AU1

EAL BASES DOCUMENT EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 4 of 27

3. Valid dose assessment indicating dose rates beyond the site boundary above 0.1 mr/ir TEDE and is expected to continue for 60 minutes or longer.

DAEC EAL INFORMIATION:

Valid means that the reading is ifiom instrumentation determined to be operable in accordance with the Technical Specifications or has been verified by other independent methods such as indications displayed on the control panels, reports from plant personnel, or radiological survey results.

UNPLANNED, as used -in this context, includes any release for which a radioactivity discharge permit was not prepared, or a release that exceeds the conditions (e.g.,

minimum dilution flow, maxim-um discharge flow, alarm setpoints, etc.) on the applicable permit. The EC/OSM should iiot waituntil 60 minutes has elapsed, but should declare the event as soon as it is determined that the release duration has or will likely exceed 60 minutes. Also, if an ongoing release is tetected and the starting time for that release is I) unknown, the EC/OSM should,-iu-the absence of data to the contrary, assume that the release has exceeded 60 minutes.

The approach taken for calculation or'gaseous radioactive effluent EAL setpoints includes use of the ODAM Table 3-2 source term computed by 9BWR-LE for the DAEC Base Case. The release is assumedto be from a'single release pont Multiple release points would be difficult to present as explicit E't teshold values 'and in any case, are addressed by off-site dose assessment is the t59MIDAS',which preferred method for determining this condition. The calculation meiods forsoint deteminaton are from ODAM Section 3.4 and are based on Regulatory Guide 1.109'metodology. 9-e' table bqlow lists the results of the gaseous effluent EAL calculations. Tlie Kaman extended range capability is used because the General Electric Offgas Stack monitor has a limited range.

AUI

-EALBASES DOCMENT EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 5of 27 GASEOUS EFFLUENT EALS -

Offgas Stack Kaman 9/10 -' Bldg (Kaman 1/2) and Reactor Bldg (Kaman 3/4, 5/6, 7/8)

Maximum flow (CFM) 10,000 , 72,000 Release Limits Concentration Release Rate Concentration Release Rate (PCi/cC) (9lCi/se (ACi/cc) (uisc Tech Spec liE-l 5.2E+5.  ;.6.2E-4-i - 2.IE+4 Unusual Event (2 xTS) 2.0E-1 I .OE+6 .E'3I - 4.2E+4 Alert (60 x TS) . 6.OE+0 3.OE+7

- ,37E-2 - . 1.3E+6 LLRPSF Kaman 12 Maximum flow (CFM) 99,000 Release Limits Concentration - Release Rate (PCi/cc)  ; I a- " (pli/sec)

Tech Spec X5.9E-4 I ' 2.8E+4 Unusual Event (2 x 1.OE-3 -, ' 5.6E+4 TS/ODM-)r l:  ;  ;- p 3_t 't~f  :

  • Alert (200 x TS) 1.OE-' ' 5.6E+6

- 4, The off-gas stack is treated as an elevated release and the turbine building and reactor building vents are treated as mixed-mode releases. The ground level setpoints are taken from the default setpoint calculitions from the quarterly sureiiace tests performed by DAEC Chemistry technicians. Reactor Building,' urbine, ildng,LLRPSF (Low Level Radwaste Processing and Storage Facility) and Offgas Stacklnoble Gas Monitor alarm setpoints are calculated based on achieving the Tech Speb/6DAM instantaneous release limit, assuming annual average meteorology as defined id the 6DAM. The Tech, Spec/ODAM Limit currently corresponds to a reactor bilding or'turbine building ventilation alarm setpoint of 6.2 E-04 pCi/cc. The motor larm setpoint can be periodically adjusted but typically does not vay by much. The DAEC EAL therefore addresses valid radiation levels'exceeding 2 times the alarm setpoint for greater than 60 minutes. Rounded off this corresponds to 1 E-3 pCi/cc. The corresponding offgas stack monitor value is l.lE-1 pCi/cc, rounded off to 1E-1 pCi/cc. TheTech Spec Limit currently for the LLRPSF building ventilation alarm setpoint is 5.9 E-04 pCi/cc. The DAEC EAL therefore addresses valid radiation levels exceeding 2 times the alarm setpoint for greater than 60 minutes. This corresponds to 1 E-3 pCi/cc.

Technical specification setpoints for radioactive liquid radiation monitors are 10 times the 10 CFR 20 Appendix B, Table 2, WaterEffluent Concentration (WEC) limits. It is the policy of DAEC to process all liquid radwaste so that no release ofradioactive liquid to the environment is allowed. The radwaste effluent line which could be used as a batch release mechanism has a trip function that prevents exceeding the DAEC release limit, however, an AUI

EAL BASES DOCUMENT EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 6 of 27 EAL has been provided. The other pathways to the environment (RHRSW - to cooling tower, RHRSW - to discharge canal) have radiation monitors with readouts going to the Control Room. These systems could become contaminated if heat exchanger leaks develop; however, historically this has not occurred in the service water systems at DAEC. These monitors are displayed on panels IC02 and 1Cl 0.

Reactor water is the likely source'of contamination through the service water systems as opposed to floor drain, detergent drain,-and chemical waste discharge. The floor drain and detergent drains go to Radwaste Processing and would be batch released to the Radwaste effluent discharge line (if such a release were to occur). The chemical discharge sump is normally a radioactivity clean system and is tested by Chemistry to ensure no contamination prior to discharging to the canial.

The setpoints for the three service water radiation effluent monitors vary because of differences in detectorefficenciesiand backgrord. Setpoints based on the same reactor water sample are listed below to show the differences. The rounded off readings will be used for the EALs for ease of reading the monitor sMles.

Monitor TS Limit Reading UE Level Alert Level GSW 1,555 CPS 1.5E+3 CPS 3E+3 CPS 3E+5 CPS RRSW & ESW to cooling 413 CPS 4E+2 CPS 8E+2 CPS 8E+4 CPS RHRSW&ESWto 507CPS 5E+2 CPS lE+3 CPS IE+5 CPS Discharge Canal II There are no significant deviations from the generic EALs. However, DAEC does not have a telemetered radiation monitoring system. As an alternative, use of field instruments was considered. It is not practical to establish an EAL based on field survey readings of 0.1 mr/hr for greater than 60 minutes because field instruments in use for emergency response do not have a threshold of detection to meet such criteria.

Hourly Whole Body Dose Corresponding to 2 x ODAM Limit for Gaseous Release ODAM limit = 500 mrem/year Whole Body Dose (10CFR20, Appendix B limit = 50 mrem/year Whole Body Dose) 2 x ODAM limit = [2 x 500 mrem/year]/8760 hours/year = 0.114 mrem Whole Body, in onel hour Rounded offto 0.1 mrem/hr AU1

-.EALBASES DOC IENt -. -  : EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT7 CATEGORY PAGE 7 of 27 Dose assessment using MIDAS is based on the EPA-400 methodology, eg., use of Total Effective Dose Equivalent (TEDE). This is somewhat different from whole body dose from gaseous effluents determined by ODAM methodology which forms the basisffor the radiation monitor readings calculated in accordance with the generic methodology. The gaseous effluent radiation monitors can' only detect noblegases.. The contribution of iodine's to TEDE could therefore only be determined either by- (1) utilizing MIDAS, or (2) gaseous effluent sampling. DAEC EAL 4 is written in terms of TEDE and the gaseous .

effluent radiation monitor readings are determined based qn ODM..

REFERENCES:

1. Offsite Dose Assessment Manual Section 6.0, 6.1.2 and i7.1.21ases
2. Emergency Plan Implementing Procedure (EPIP) 3.3, Dose 'Assessment and Protective Action
3. Radiation Protection Calclation No. E95001C.,- yAions Leyels Based on Effluent Radiation Monitors, January 24, 1050 '  : J.
4. UFSAR Section 11.5, Process and Effluent Radiation onitoring and Sampling Systems
5. NEIMethodologyfor Development ofEnergenc Action-iiLels NUMARCJNESP-007 Revision 4, May 1999 AU1

I EAL BASES DOCUMENT EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 8 of 27 AU2 Unexpected Increase in Plant Radiation EVENT TYPE: Onsite Rad Conditions OPERATING MODE APPLICABILITY: All EAL THRESHOLD VALUE: (1 or 2)

1. Uncontrolled loss of reactor cavity or fuel pool water level with all spent fuel assemblies remaining covered by water as indicated by ANY of the following:
  • Report to the control room.
  • Valid fuel pool level indication (LI-3413) below 36 feet and lowering.
  • Valid WR GEMAC Flobdup indication (LI4541) coming on scale.

OR J,

2. Unexpected ARM reading offscale high or above 1000 times normal* readings.
  • Normal levels can be considered as the highest reading in the past twenty-four hours excluding the current peak value.

DAEC EAL INFORMATION:

There are no significant deviations'from the generic EAls. DAEC'does not have a spent fuel transfer canal.

Uncontrolledmeans that the condition is not the result of planned actions by the plant staff in accordance with procedures. Valid means that the reading is from instrumentation determined to be operable in accordance with the Technical Specifications or has been verified by other independent methods such as indications displayed on the control panels, reports from plant personnel, or radiological survey results.

There are three methods to determine water level decreases of concern. The first method is by report to the control room. The other methods include use of the Floodup level indicator and the spent fuel pool level indicator. These are further described below.

During preparation for reactor cavity flood up prior to entry into refuel mode, reactor vessel level instrument LI4541 (WR GEMAC, FLOODUP) on control room panel 1C04 is placed AU2

i.

.EAL BASES DOCUMENT EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL-EFFLUENT CATEGORY PAGE 9 of 27 in service by I&C personnel connecting a compensating air signal after the reference leg is disconnected from the reactor head. Normal refuel water level is above the top of the span of this flood up level indicator. A valid indication (e.gt, not due to loss of compensating air signal or other instrument channel failure) of reactor cavity level coming on span for this instrument is used at DAEC as an indicator ofuncontrolled reactor cavity level decrease.

DAEC Technical Specifications require a minimum of 36 feet of waterinthe spent fuel pool. During refueling, the gates between the reactor cavity and the refueling cavity are removed and the spent fuel pool level indicator 1 3413 is used to monitor refueling water level. Procedures require that a normal refueling water leyb1e maintained at 37 feet 5 inches. A low level alarm'actuates when spent fuel pooliever iops below 37 feet 1 inch.

Symptoms of inventory loss at DAEC include visual observ4a tign.of.decreasing water levels in reactor cavity or spent fuel storage pool, Reactor Building A fuel storage pool radiation monitor or refueling area radiation monitor alrps,, observation of a decreasing trend on the spent fuel pool water level indicator, and actuation of the spent fuel pool low water level alarm. To eliminate minor level pe uibatioqps.T*concern, DAEC uses LI 3413 indicated water level below 36 feet and 1o'wering.

Increased radiation levels can be detected by the local refueling floor area radiation monitors, the refueling floor Continuous Air Monitor (CAM) alarm, refueling areas radiation monitors, fuel pool ventilation exhaust monitors; atid by Standby Gas Treatment (SGBT) System automatic start Applicable area radiation monitors include those that are displayed on Panel 1C02 and alarmed on Panel I C04B.. The DAEC EAL has also been written to reflect the case where an ARM may go oficaleighprirto reaching 1,000 times the normal reading.

NOTE: On Annunciator Panel 1C04B, the indicators listed below are expected alarms during pre-planned transfers of highly radioactive material through the affected area. If an HP Technician is present, sending an Operator is not required. Radiation levels other than those expected should be promptly investigated. The indicators are high radiation alarms from the Hot Laboratory or Administrative Building the new fuel storage area, and the radwaste building.,

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EAL BASES DOCUMENT EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 10 of 27

REFERENCES:

1. Alarm Response Procedure CARP) C04B, Reactor Water Cleanup and Isolation
2. Technical Specification 3.7.8, Spent Fuel Pool Water Level
3. Emergency Plan Implementing Procedure (EPIP) 3.1, Inplant Radiological Monitoring, Attachment 1, ARM Locations
4. Emergency Operating Procedures (EOP) Basis Document, Breakpoints for RCIL & L
5. Surveillance Test Procedure (STP) 3.0.0.0-01 PA, Daily and Shift Instrument Checks
6. Integrated Plant Operating Instruction (IPOI) 8, Outage and Refueling Operations
7. Core Alterations, RFP403, Procedure for Moving Core Components Between Reactor Core and Spent Fuel Pool, Within the Reactor Core, or Within the Spent Fuel Pool
8. NEI Met hodoJogyfor Develop-nent qfEmergency Action LeveIs NUALRC/NESP-007 Revision 4, May 1999 AU2

EALBASSES OCUMENT: EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 11 of 27 AA1 Any Unplanned Release of Gaseous or Liquid Radioactivity to the Environment that Exceeds 200X the Offsite Dose Assessment Manual (ODAM) Limit and is Expected to Continue for 15 Minutes or Longer -

EVENT TYPE: Offsite Rad Conditions -

OPERATING MODE APPLICABILITY: All -

EAL THRESHOLD VALUE: (1 or 2 or 3 or 4)

1. Valid Reactor Building ventilation rad monitor (Kaman 3/4, 5/6, 7/8 ) or Turbine Building ventilation rad monitor (Kaman 1/2) reading above 3 E-2 tiCi/cc and is expected to continue for 15 minutes or longer.

OR Valid Offgas Stack rad monitor (Kaman 9/10) reading above 6 E+0 pCi/cc and is expected to continue for 15 minutes or longer.

OR Valid LLRPSF rad monitor (Kaman 12) reading above I E-1 pCi/cc and is expected to continue for 15 minutes or longer. - I OR Valid GSW rad monitor (RIS-4767) reading above 3E+5 CPS and expected to continue for 15 minutes or longer. I OR-Valid RHRSW & ESW rad monitor (RM-1997) reading above 8E+4 CPS and expected to continue for 15 minutes or longer. I OR Valid RHRSW & ESW Rupture Disc rad monitor (RM-4268) reading above E+5 CPS and expected to continue for 15 minutes or longer.

OR

2. Confirmed sample analyses for gaseous or liquid releases indicates concentrations or release rates with a release duration expected to continue for 15 minutes or longer in excess of 200 times ODAM limit OR AA1

EAL BASES DOCUMENT' EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 12 of 27

3. Valid site boundary radiation reading of greater than 10 mr/hr above normal background and is expected to continue for 15 minutes or longer.

OR

4. Valid dose assessment indicating dose rates beyond the site boundary above 10 mr/br TEDE and is expected to continue for 15 minutes or longer.

DAEC EAL INFORMATION:

Valid means that the reading is from instrumentation determined to be operable in accordance with the Technical Specifications or has been verified by other independent methods such as indications displayed on the control panels, reports from plant personnel, or radiological survey results. In a case where data from Kaman readings is being used to determine whether an EAL threshold value has been exceeded, Valid means that flow through the associated Kaman Monitor ha been verified and does exist as indicated in gCi/sec on SPRAD. -

UNPLANNED, as used in this context, includes any release for which a radioactivity discharge permit was not prepared, or a release that exceeds the conditions (e.g.,

minimum dilution flow, maximum'discharge'floQW, alarm setpoints, etc.) on the applicable permit. The EC/OSM'shq'uld not wait until 15 miutes has elapsed, but should declare the event as soon as it is determined that the release duration has or will likely exceed 15 minutes. Also, if an ongoing reIeas& is detected and the startingtime for that release is unknown, the EC/OSM should, in the absence of data to the contrary, assume that the release has exceeded 15 minutes.

.~~

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AA1

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EAL-BASES DOCUMENT . EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT. CATEGORY PAGE 13 of 27 Gaseous Effluent EALs

. Offas KauanStack9/10 ' 'Turbine Bldg (Kaman 1/2) and Offgas Stc aa /0Reactor Bldg (Kanman 3/4, 56,78)

Maximum flow (CFM) 10,000 _ 72,000; Release Limits Concentration Release Rate Concentration Release Rate

-'_(__Ci/cc) (Silsec) i_ (OCi/cc) ' (jiCi/sec)

Tech Spec l.lE-1 5.2E+5' 6.2E4' 2.E+4 Unusual Event (2 x TS) 2.OE-1 1 OE+6 1.2E-3 4.2E+4 Alert (60 x TS) 6.0E+0 3.E+7 . '37E-2 1.3E+6.

LLRPSF Kaman 12 Maximum flow (CFM) 99,000  : .i p.

Release Limits Concentration J RdelaRg1

_______________(P.ci/cc)(.ticY Tech Spec 5.9E-4 2,8E+4,",

Unusual Event (2 xTS) 1.OE-3 _ _ _ __ _ _ _ _ _ _ _

Alert(200xTS) - 1.OE-1 56E+  :

The off-gas stack is treated as an elevated release and the turbine building and reactor .

building vents are treated as mixed-mode releases. The&od levelsetpoints are taken from the default setpoint calculations firm-thequrtery siviiance tests perodmed by DAEC Chemistry technicians. Reactor Building, Turbine .. idig LLRPSF (Low Level

'Radwiste Processing and Storage Facili) and Offgas Stac 4oble Gas Monitor alann setpoints are calculated based on achieving the Tech Spc 'iisataus release limit assuming annual average meteorology as defined in the ODKM. The Tech Spec Limit cMently corresponds to a'reactor building or turbine bilding ventilation alam setpoint of 6.2 E-4 pCi/cc. The monitor alarm setpoint can be periodically adjusted but typically does not vary by much. For the Offgas Stack, Reactor Building and Turbine building KAMAN monitor readings, DAEC chose to multiply the technical specification concentration by a factor of 60 (instead of 200) in order to allow for a logical step progression in monitor setpoints from the AUl through AAl to ASI. The DAEC EAL therefore addresses valid radiation levels exceeding 60 times the alarm setpoint for greater han 15 minutes. Rounded down, this corresponds to 3 E-2 pCi/cc. The corresponding offgas stack monitor value is 6.6 pCi/cc, rounded down to 6 E+O pCi/cc. The Tech Spec/ODAM Limit currently for the LLRPSF building ventilation alarm setpoint is 5.9 E-04 pCi/cc. The DAEC EAL therefore addresses valid radiation levels exceeding 200 times the alarm setpoint for greater than 15 minutes. This corresponds to I E-l pCi/cc.

Technical specification setpoints for radioactive liquid radiation monitors are 10 times the 10 CFR 20 Appendix B, Table 2, Water Effluent Concentration (WEC) limits. It is the policy of DAEC to process all liquid radwaste so that no release of radioactive liquid to the AA1

EAL BASES DOCUMENT' EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 14 of 27 environment is allowed. The radwaste effluent line which could be used as a batch release mechanism has a trip function that prevents exceeding the DAEC release limit, and therefore no EAL limits are provided. The other pathways to the environment (RHRSW - to cooling tower, RHRSW - to discharge canal) have radiation monitors with readouts going to the Control Room. 'These systems could become contaminated if heat exchanger leaks develop; however, historically this has not occurred in the service water systems at DAEC.

These monitors are displayed on paneis. 1C02 and ClO.

Reactor water is the likely source of contamination through the service water systems as opposed to floor drain, detergent drain, and chemical waste discharge. The floor drain and detergent drains go to Radwaste Processing and would be batch released to the Radwaste effluent discharge line (if such a release were to occur). Thechemical discharge sump is normally a radioactivity clean system and is tested by Chemistry to ensure no contamination prior to discharging to the canal. ,

The setpoints for the three service water radiation effluent monitors vary because of differences in detector efficiencies and background. Setpoints based on the same reactor water sample are listed below to show the differences. The rounded off readings will be used for the EALs for ease of reading the monitor scales.

Monitor TS/ODAM Limit Reading UE Level Alert Level GSW 1,555 CPS 1.5E+3 CPS 3E+3 CPS 3E+5 CPS RHRSW & ESW to cooling 413 CPS 4E+2 CPS 8E+2 CPS 8E+4 CPS to w r_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

RHRSW & ESW to 507CPS 5E+2 CPS 1E+3 CPS 1E+5 CPS Discharge Canal DAEC does not have a telemetered radiation monitoring system. As an alternative, DAEC uses valid field survey readings outside the site boundary greater than 10 mr/hr or greater than 50 mr/hr CDE Thyroid.

Hourly Whole Body Dose Corresponding to 200 x ODAM Limit for Gaseous Release ODAM limit = 500 mrem/year Whole Body Dose (10CFR20, Appendix B limit = 50 mrem/year Whole Body Dose) 200 x ODAIVI limit = [200 x 500 mrem/year]/8760 hours/year = 11.4 rmrem Whole Body in one hour Rounded off to 10 mrem/hr i!

AA1

.EAL BASES D C MENT, EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 15 of 27 Dose assessment using MIDAS is based on the EPA-400 methodology, eg., use of Total Effective Dose Equivalent (TEDE). This is somewhat different from whole body dose from gaseous effluents' determined by ODAM methodology which forms the basis for the radiation monitor readings calculated in AUI in accordance 1vit1ithe generic methodology.

The gaseous effluent radiation monitors Can only detect noble gases.' The contribution of iodine's to TEDE could therefore only be detennined either by- (1) utilizing NMIAS, or (2) gaseous effluent sampling. DAEC EAL 4 is written in teni of TEDE and the gaseous effluent radiation monitor readings are determined based on'Ot)AM.'

REFERENCES:

1. Offsite Dose Assessment Manual Section 6.0, 6.1.2 Aiid 7.,2 Base
2. Emergency Plan hmplemnenting~ Procedure (PIP) 3. "kgAhessen ~nd Protective Action'. '.

3.Radiation Protection Calculation No. 95-001-C, Eegn~~in eesBsdo Effluent Radiation Monitors, January.24, 1995

4. UPSAR Sectionl11.5, Process ahdEffl tejiadiatdI M-66no 'nganidSampling
5. EPA 2 O i a ua fP oetv AA '-- toh (!M' d .A zd ProtectiveActions fr, 1~~~ NuclearIncidents i r
6. NATlMethodology for Development ofEmergency Action Levels NUAMRC/NESP-007 Revision 4, May 1999 AA1

EAL BASES DOCUMENT EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 16 of 27 AA2 Major Damage to Irradiated Fuel or Loss of Water Level that Has or Will Result in the Uncovering of Irradiated Fuel Outside the Reactor Vessel EVENT TYPE: Onsite Rad Conditions OPERATING MODE APPLICABILITY: All EAL THRESHOLD VALUE: ( or 2 or 3 or 4)

1. Report of either qftlte following-
  • Valid Refueling Floor North End (RM-9163), Refueling Floor South End (RM-9164), or New Fuel Storage Area (RM-9153) ARM Reading above 10 mr/hr
  • Valid Spent Fuei Storage Area ARM (RM-91 78) Reading above 100 mr/hr OR
2. Report of Visual observation of irradiated fuel uncovered.

OR J)

3. Valid waterlevel readingbelow 450" as indicated on LI-4541 (floodup) forthe Reactor Refueling Cavity that will result in Irradiated Fuel uncovering.

OR '

4. Valid Fuel Pool water level indication (LI-3413) below 16 feet that will result in Irradiated Fuel uncovering.,

DAEC EAL INFORMATION:

Valid means that the reading is from instun entation determined to be operable in accordance with the Technical Specifications or has been verified by other independent methods such as indications displayed on the control panels, reports from plant personnel, or radiological survey results. Valid alarms are solely due to damage to irradiated fuel or loss of water level that has or will result in the uncovering of irradiated fuel.

There are no significant deviations from the generic EALs Icreased radiation levels can be detected by the local radiation monitors, in-plant radiological surveys, new fuel and spent fuel storage area radiation monitor alarms displayed on panel 1C04B, fuel pool ventilation exhaust monitors, and by Standby Gas Treatment (SBGT) System automatic start Applicable area radiation monitors include RM-9163, RM-9164, RM-9153, and RM-9178. l These monitors are located in the north end of the refuel floortffhe south end of he rbfuel floor, the new fuel vault area, and near the spent fuel pool, respectively. IJ AA2

-EAL BASES DOCUMENT  : - EBD-A

^ 5~-

-a -;'--: -- - -I 0 i . (::s;=>-:::. - ;f* Rev.6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 17 of 27 Per ARP lC04B, the applicable area radiation monitor alarms actuate when radiation levels increase above 100 mr/hr in the spent fuel pool area or above 10 mr/hr in the other three areas of concern. If a valid actuation of these alarms were to occur, the refueling floor would be immediately evacuated. Thus, a report of a fuel handling accident with either valid actuation of the fuel area alarms on panel lCO4B or with measured radiation levels in the spent fuel pool or north fuel area are used to address the generic concern consistent with DAEC design and procedures.

During preparation for reactor cavity flood uprprior to entry into ref el mode, reactor vessel level instrument LI-4541 (WR GEMAC, FLOODUP) on control room panel 1C04 is placed in service by I&C personnel connecting a compensating air gigniafter the reference leg is disconnected from the reactor head. Normal refuel water Oyel'is above the top of the span of this flood up level indicator.A valid on-scaledicaiag;,tt due to loss of compensating air signalor other instrunent channel failutfi this instrument can be used to determine uncontrolled loss of water level in the reactor cavity.

During refueling, the gates between the reactoricavity and the jefueling cavity are removed and the spent fuel pool level indicator LI 3413 is used to monitor refueling water level. This

-measures the common water level in the reactor cavity and the fuel pool. The bottomof the fuel transfer slot between the spent fuel pool and the reactor cvity is 16 feet above the -

bottom of the spent fuel pool. The top of the active fuel in the'spent fuel'storage racks is slightly less than 13 feet 9 inches above the bottom of the spent fuel pool. Therefore, postulated failures which drain the reactor cavity through the reactor vessel cannot uncover fuel in the spent fuel storage racks. However, alid:iddid6at idfspent fuel pool level less than 16 feet would indicate that spent fuel in the storage racks may potentially become uncovered.

RFP403 requires that upon a loss of water level situation, that the refueling crew on the l refueling floor shall discharge any fuel assembly on the fuel grapple as follows:

  • If a fuel assembly iscurrentlybeing withdrmwn fom a slot in the core or spent fuel pool, immediately reinsert it into that slot.
  • If a fuel assembly is being transferred and is still over or near the core, insert it into the closest available slot in'the core.
  • If a fuel assembly is, being transferred and is overornearthe spent fuel pool, insertit into the closest available slot in the spent aiilracks., ,

Following these actions, the refueling floors be evacuated of all personnel -The DAEC EAL is written to address the generic concern tlat a spent fuel assembly was not fully covered bywate, This can either be by visual observation of an uncovered spent fuel AA2

EAL BASES DOCUMENT EBD-A

f ~ ~ EB Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 18 of 27 assembly or by trending fuel pool level in the control room if a spent fuel assembly could not be placed in a safe storage location specified by RFP 403 as described above.

REFERENCES:

1. Alarm Response Procedure (ARP) C04B, Reactor Water Cleanup and Isolation
2. Technical Specification 3.7.8, Spent Fuel Pool Water Level
3. Emergency Operating Procedures (EOP) Basis Document, Breakpoints for RC/L & L
4. Emergency Plan Implementing Procedure (EPIP) 3.1, Inplant Radiological Monitoring, Attachment 1,ARM Locations
5. Surveillance Test Procedure (STP) 3.0.0.0-01, Daily and Shift Instrument Checks
6. Integrated Plant Operating Instruction(1POI) 8, Outage and Refueling Operations
7. Core Alterations, RFP403, Procedure for Moving Core Components Between Reactor Core and Spent Fuel Pool, Within the Reactor Core, or Within the Spent Fuel Pool
8. Bechtel Drawing C-492, Reactor Building - Reactor Well, Spent Fuel & Dryer-Separator Pool General Arrangement, Rev. 6
9. Bechtel Drawing C-493, Reactor Building- Spent Fuel Liner Plan Elevations and Details, Sheet 1, Rev. 6
10. Holtec International Drawing No. 1045, Rack Construction - Spent Fuel Storage Racks, Rev. 3
11. NEI MethodologyforDevelopment ofEmergency Action Levels NUMARC/NESP-007 Revision 4, May 1999 AA2
EAL BASES DOCUMENT. EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT-ATEGORY PAGE 19 of 27 AA3 Release of Radioactive Material or Increases in Radiation Levels Within the Facility That Impedes Operation of Systems Required to Maintain Safe Operations or to Establish or to Maintain Cold Shutdown EVENT TYPE: Onsite Rad Conditions OPERATING MODE APPLICABILITY: All'
  • ! . Q* ig*  ::

EAL THRESHOLD VALUE: (1or 2) ' -

1. ValidControl RoomAreaRadiation Monitor(RM-9.162)'rading above 15'mr/r.l OR'~~~~~~~'I
2. Valid North CRD Module Area Radiation Monitor (RML4 68) reading above 500 mr/hr, affecting the Remote'ShutdownPanel,,'lC38&' .' '

DAEC EAL INFORMATION. 1 i' Valid means that the reading is from instrumentation deterhiied to be operable in accordance with the Technical Specifications or has been verified by other independent methods such as indications displayed on the control panels, reports from plant personnel, or radiological survey results.

There are no significant deviations fiom the generic EALs. Per the UFSAR, the control room is the only area that is required to be continuously occupied to achieve and maintain safe shutdown following design basis accidents. The capability exists for plant shutdown from outside the main control room in the event that the control room becomes uninhabitable using remote shutdown panel 1C388. The RB 757 CRD North ARM-9168 is in the vicinity of the Remote Shutdown Panel and is used to monitor radiation levels to determine habitability for that area.

Expected increases in monitor readings due to controlled evolutions (such as liffing the steam dryer during refueling) do not result in emergency declaration. Nor should momentary increases due to events such as resin transfers or controlled movement of radioactive sources result in emergency declaration. In-plant radiation level increases that would result in emergency declaration, are also unWlanned, e.g., outside the limits established by an existing radioactive discharge permit AA3

EAL BASES DOCUMENT - EB-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 20 of 27

REFERENCES:

1. Alarm Response Procedure (ARP) C04B, Reactor Water Cleanup and Isolation
2. Abnormal Operating Procedure (AOP) 913, Fire
3. Abnormal Operating Procedure (AOP) 914, Security
4. Abnormal Operating Procedure (AOP) 915, Shutdown Outside Control Room
5. Surveillance Test Procedure (STP) 3.0.0.0-01, Daily and Shift Instrument Checks
6. Integrated Plant Operating Instruction (IPOI) 8, Outage and Refueling Operations
7. Emergency Plan Implementing Procedure (EPIP) 3.1, Inplant Radiological Monitoring
8. UFSAR Section 6.4, Habitability Systems
9. Bechtel Calculation DA-4, Project Number 265-002, Control Room Habitability, 9/3/80
10. NEI Methodologyfor Development ofEmergency Action Levels NUMARC/NESP-007 Revision 4, May 1999 AA3

EAL BAES DOCUMENT EBD-A Rev.6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 21 of 27 ASI Site Boundary Dose Resulting from an Actual or Imminent Release of Gaseous Radioactivity Exceeds 100 mrem TEDE or 500 mrem CDE Thyroid for the Actual or Projected Duration of the Release EVENT TYPE: Offsite Rad Conditions -

OPERATING MODE APPLICABILiTY All EAL TIIRESHOLD VALUE: (1 or 2 or 3)

1. Valid Reactor Building ventilation rad monitor (Kaman'314, 5/6, 7/8) orTurbine Building ventilation rad monitor (Kaman 1/2) reading above 6 E-2 4iCi/cc and is expected to continue for 15 minutes or longer. (Dose assessment not available.)

OR Valid Offgas Stack rad monitor (Kaman 9/10) reading above 4 E+1 Ci/cc and is expected to continue for 15 minutes or longer. (Dose assessment not available)

OR

2. Field survey results indicate site boundary dose rates exceeding 100 mrem/hr expected to continue for more than one hour, or analyses of field survey samples indicate CDE Thyroid of 500 mrem for one hour of inhalation.

OR

3. Dose assessment determines integrated accident dose projection outside the site boundary above 100 mrem TEDE or above 500 mnrn CDE Thyroid.

DAEC EAL INFORMATION:

Valid means that the reading is from instrumentation determined to be operable in accordance with the Technical Specifications or has been verified by other independent methods such as indications displayed on the control panels, reports from plant personnel, or radiological survey results. In a case where data from Kaman readings is being used to determine whether an EAL threshold value has been exceeded, Valid means that flow through the associated Kaman Monitor has been verified and does exist as indicated in pCi/sec on SPRAD.

The preferred method for declaration of ASI is by means of Dose Assessment using the MIDAS computer model. However, if Kaman monitor readings are sustained for longer than 15 minutes and the required MIDAS dose assessments cannot be completed within this period, then the declaration can be made using Kaman readings PROVIDED the readings AS1

EAL BASES:DOCUMENT l EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 22 of 27 are not from an isolated flow path. If Kaman readings are not valid, field survey results may be utilized.

DAEC's Meteorological Information and Dose Assessment System (MIDAS) was utilized to determine the Kaman monitor limits. Eight separate combinations of release point, source term, meteorological conditions and equipment status were analyzed. Pathways considered were the offgas stack, the turbine building exhaust vent and a single reactor building exhaust vent. Multiple release points were not considered. In this same vein, it was assumed that only one o the'three reactor building vents is on during the release.

The source terms used have been pre-loaded into MIDAS and are the default mixes associated with a loss of coolant accident (LOCA) and a control rod drop (CRD). The LOCA mix was usedin conjunction with a release via the offgas stack while the CRD mix was used for releases via the turbin& or reactor building vents. The source term for a release via the offgas stack is furtheri impacted by the status'of the standby gas treatment system.

The status of that system was also taen into consideration.

Based on 1995 data (NG-96&098 );the atmospheric stabilitywas classified as Pascal E 33%

of the time. Consequently, both clasificationswere evaluated. Based on the same report, the most common wind speeds'were '

Pascal Class Altitude Speed (mph)

D 156' 8-12 D 33' 8-12 E 156' 8 - 12 E '33' 4- 7 Though the temperature setting has no impact on the MIDAS calculations, a value must be entered in order for the program to run. Consequently, the temperature was arbitrarily set at 50 F.

The rain estimate was set at zero, to eliminate any on site washout of radioactive material.

For the first MIDAS runs a Ci/cc concentration was assumed. The results'of these runs were then normalized to the limits, thus generating a theoretical Kaman limit. Additional MIDAS runs were made with these theoretical limits as input to verify the normalization process. In addition to the total integrated dose, MIDAS calculates a peak whole body DDE rate resulting fiom the plume and a peak thyroid CDE rate resulting from inhalation.

Because the ASI and AG1 KAMAN limits are to be based on a one-hour exposure, establishing concentration limits so these peak values match the NUMARC limits is acceptable.

ASI

EALBASES OCUMENT EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENTCATEGORY, PAGE 23 of 27 Site Area Geneal 1nitiating Condition . Emergency Emergency

__ __ _____ __ __ __ __ ____ _ _ _ . A SI AG Valid Turbine or Reactor Building ventilation rad monitor (KAMAN) reading.for more than 15 0.06 jCi/cc 0.6 Ci/cc minutes above: . _____,..__..,

DAEC does not have a telemetered radiation monitoring system. As an alternative, DAEC uses valid field survey readings outside the siteboundarygtpldeti e.,ifdoses are greater than 100 mr/hr TEDE or greater than 500 mr/hr CDE Thyroid.

Dose assessment using MIDAS is based on the EPA-409,mqth9 gy, e.g. ,use of Total Effective Dose Equivalent (TEDE) and Committed Dose Eivalent (CDE) Thyroid.:

TEDE is somewhat different from whole bo dypsefom gasqous effluents determined by ODAM methodology which forms the basis for~tleadi.tiopjtorreadings calculated in AU1. These factors can introduce differences that We tl slarge as those introduced by using TEDE versus whole body dose. The gaseous effluent radiation monitors can only detect noble gases. The contribution of iodine's t 1 ) ;4E Thyroid could therefore only be determined either by (1) utilizing the squrceerm t ~rein MIDAS, or (2),

gaseous effluent sampling. Therefore, DAEC EAL Thresholdyalue 3 is written in terms of TEDE and CDE Thyroid.

REFERENCES:

1. Offsite Dose Assessment Manual, Section 6.0, 6.1.2 and 7.1.2, Bases
2. Emergency Plan Implementing Procedure (EPIP) 3.3, Dqse Assessment and Protective Action
3. Radiation Protection Calculation No. 95-001-C, EmergencyActions Levels Based on Effluent Radiation Monitors,:January 24, 1995
4. Radiation Engineering Calculation No. 96-007-A, Determination of DAEC Radioactive Release hitiating Conditions for AS! & AG1 Emergency Classifications, July 3, 1996
5. UFSAR Section 11.5, Process and Effluent Radiation Monitoring and Sampling Systems
6. EPA 400-R-92-001, ManualofProtectiveAction Guides and ProtectiveActions for NuclearIncidents
7. NElMethodologyfor Development ofEmergencyAction Levels NUMARC/NESP-007:

Revision 4, May 1999 .

- ~~~~AS1

EAL BASES DOCUMENT EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 24 of 27 AG1 Site Boundary Dose Resulting from an Actual or Imminent Release of Gaseous Radioactivity that Exceeds 1,000 mrem TEDE or 5,000 mrem CDE Thyroid for the Actual or Projected Duration of the Release EVENT TYPE: Offsite Rad Conditions OERATING MODE APPLICABILITY: All EAL THRESHOLD VALUE: 1 or 2 or 3)

1. Valid Reactor Building ventilation rad monitor (Kaman 3/4, 5/6, 7/8) or Turbine Building ventilation rad monitor (Kaman'l/2) reading above 6 E-I ipCi/cc and expected to continue for 15 minutes or longer. (Dose assessment not available)

OR Valid Offgas Stack rad onitor (Kaman 9/19)reading above 4 E+2 PCi/cc and expected to continue for 15 minutesorong.r, (Dose assessment not available)

OR

2. Field survey results indicate site boundary dose rates exceeding 1,000 mremvhr expected to continue for more than one hour, or analyses of field survey samples indicate CDE Thyroid of 5,000 mrem for one hour of inhalation.

OR

3. Dose assessment determines integrated accident dose projection outside the site boundary above 1,000 mrem TEDE or above 5,000 mrem CDE Thyroid.

DAEC EAL INFORMATION:

Valid means that the reading is from instrumentation determined to be operable in accordance with the Technical Specifications or has been verified by other independent methods such as indications displayed on the control panels, reports from plant personnel, or radiological survey results. In a case where data firom Kaman readings is being used to determine whether an EAL threshold value has been exceeded, Valid means that flow through the associated Kaman Monitor has been verified and does exist as indicated in gCi/sec on SPRAD.

AG1

r - -_7=7

JEALBASES DOCUMENT -. EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT-CATEGORY PAGE 25 of 27 The preferred method for declaration of AGI is by means of Dose Assessment using the MIDAS computer model. However, if Kaman monitor readings are sustained for longer than 15 minutes and the required MIDAS dose assessments cannot be completed within this .

period, then the declaration can be made using Kaman readings PROVIDED the readings are not from an isolated flow path. If Kaman readings are not valid, field survey results may be utilized.

DAEC's Meteorological Information and Dose Assessment.Systemn(MIDAS) was utilized to determine the Kaman monitor limits. Eight separate combinations of release point, source term, meteorological conditions and equipment status were analyzed. Pathways-considered were the offgas stack, the turbine building exhaust vent and a single reactor building exhaust vent. Multiple release points were not considered. In this same vein, it was assumed that only one of the three reactor building vents is on during the release.

The source terms used have been pre-loaded into MIDAS and are the default mixes associated with a loss of coolant accident (LOCA) aid,4a ipfl 4 oddrop (CRD). The LOCA mix was used in conjunction with a release via the offgas stack while the CRD mix was used for releases via the turbine or reactor building vents. The source term for a release via the offgas stack is farther impacted by the status ofthe diidby gas treatment system.:

The status of that system was also taken into cideratia'  ; '

Based of 1995 data (NG-96-0987), the atmospheric stability was classified as Pascal E 33%

of the time. Consequently, both classifications were evalated;. Based on the same report, the most common wind speeds were: -

Pascal Class Altitude Speed (mph)

D 156'- 8-12 D 33'.., - 8-12 E 156L - -,v 8-12 E 33' 4-7 Though the temperature setting has no impact on the MIDAS calculations, a value must be entered in order for the program to run. Consequently, the temperature was arbitrarily set at 50F.

The rain estimate was set at zero, to eliminate any oAi site washout ofradioactive material.

For the first MIDAS runs a Ci/cc concentatiop was assumed. The results of these runs were then normalized to the limits, thus generaktng a theoretical Kaman limit Additional MIDAS runs were made with these theoretec1 limits as input to verify the normalization process.

AGI

EAL BASES DOCUMENT EBD-A Rev. 6 ABNORMAL RAD LEVELS/RADIOLOGICAL EFFLUENT CATEGORY PAGE 26 of 27 In addition to the total integrated dose, MIDAS calculates a peak whole body DDE rate resulting from the plume and a peak thyroid CDE rate resulting from inhalation. Because the ASI and AGI Kaman limits are to be based on a one-hour exposure, establishing concentration limits so these peak values match the NUMARC limits is acceptable.

Site Area General Initiating Condition Emergency Emergency ASI AGI Valid Turbine or RB ventilation rad monitor (Kaman) reading for more than 15 minutes above: 0.06 glCi/cc 0.6 giCi/cc Valid Offgas Stack ventilation rad monitor (Kaman) reading for more than 15 minutes above: 40 itCi/cc 400 pCi/cc DAEC does not have a telemetered radiation monitoring system. As an alternative, DAEC uses valid field survey readings outside the site boundary to determine if doses are greater than 1,000 mr/hr TEDE or greater than 5,000 mr/hr CDE to the Thyroid.

Dose assessment using MIDAS is based on the EPA-400 methodology, e.g., use of Total l/

Effective Dose Equivalent (TEDE) and Committed Dose Equivalent (CDE) Thyroid.

TEDE is somewhat different from whole body dose from gaseous effluents determined by ODAM methodology which forms the basis for the radiation monitor readings calculated in AUL. These factors can introduce differences that are at least as large as those introduced by using TEDE versus whole body dose. The gaseous effluent radiation monitors can only detect noble gases. The contribution ofiodine's to TEDE and CDE Thyroid could therefore only be determined either by. (1) utilizing the source term mixture in MIDAS, or (2) gaseous effluent sampling. Therefore, DAEC EAL Threshold Value 4 is written in terms of TEDE and CDE Thyroid.

REFERENCES:

1. Offsite Dose Assessment Manual, Section 6.1.2 and 7.1.2, Bases
2. Emergency Plan Implementing Procedure (EPIP) 3.3, Dose Assessment and Protective Action
3. Radiation Protection Calculation No. 95-001-C, Emergency Actions Levels Based on Effluent Radiation Monitors, January 24, 1995
4. Radiation Engineering Calculation No. 96-007-A, Determination of DAEC Radioactive Release Initiating Conditions for ASI & AGI Emergency Classifications, July 3, 1996
5. UFSAR Section 11.5, Process and Effluent Radiation Monitoring and Sampling Systems AG1

EAL1BASES DOCUMENT EBD-A Rev. 6 ABNORMAL RAD LEVELSIRADIOLOGICAL EFFLUENT CATEGORY PAGE 27 of 27

6. EPA 400-R-92-001, Manual ofProtective Action Guidesand Protective Actionsfor Nuclear Incidents
7. NEI Met hodology for Development ofEmer-gency Action Leiels NUMARCINESP-007 Revision 4, May 1999.

AGI

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