ML20039C702
| ML20039C702 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 12/21/1981 |
| From: | Parker W DUKE POWER CO. |
| To: | Adensam E, Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8112300059 | |
| Download: ML20039C702 (8) | |
Text
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DUKE Powsu Coxiwxy l'owen licitnixo
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.Mr. Harold R. Denton, Director 4
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Office of Nuclear Reactor Regulation j
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U. S. Nuclear. Regulatory Commission
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x Attention:
Ms. E. G. Adensam, Chief-4
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j Licensing Branch No. 4 qG $
Re: McGuire Nuclear Station-
. Docket Nos. 50-369, 50-370
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Upgraded Meteorological System i
Dear Mr. Denton:
i Pursuant'to McGuire Operating License Condition 2.C.(11)n(2), attached is a functional description of the upgraded meteorological system to be implemented at McGuire Nuclear Station. Five copies of this description are included in 4
this submittal.
t The subject license condition requires that the upgraded system be operational by October 1, 1982. Therefore, it would be appreciated if the NRC Staff review of this matter could be expedited and any comments provided to Duke Power Company j
1 in a timely manner since design and procurement activities are in progress.
Please advise if there are any questions regarding this matter.
F.
Ve [ truly yours, 0p/
L. -
e William O. Parker, Jr.
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GAC/j fw Attachment cc:
Mr. P. R. Bemis
~Mr. James P. O'Reilly, Director Senior Resident.__ Inspector U. S. Nuclear. Regulatory Commission McGuire Nuclear Station Region II
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j 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 fDO s
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f 8112300059 8112211' 1
PDR ADOCK 05000369 F
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--._ n McGuire Meteorological System INTRODUCTION in response to guidance provided by NUREG-0654, Revision I and supporting docu-ments, Regulatory Guide 1.23, Proposed Revision 1, Regulatory Guide 1.111, Revision 1, and Regulatory Guide 1.109, Duke has reviewed the existing meteoro-logical system at McGuire Nuclear Station and, based on that review, has devel-oped a plan for upgrading the meteorology system.
This functional description of the upgraded meteorological system is intended to provide compliance with the January 1, 1982 submittal date.
The present meteorological measuremer.t program at McGuire Nuclear Station was originally designed to best describe the meteorological conditions on-site by taking into account source characteristics, terrain features and modeling needs.
Due to revisions to guidelines, Duke has developed changes to upgrade assesstent capabilities and reliability of the meteorological programs at McGuire Nuclear Station.
Basically, these changes will:
1)
Establish a capability to assess ne: r real time 15 minutes averaged / validated data with a 12-hour recall and associated dose estimates within 15 minutes I
of request that account for variability in travel path of effluent material.
2)
Improve reliability and accuracies through upgraded instrumentation and upgrading of meraorological data, other dose related measurements, and dose estimates as needed.
[fftUENT DISPERSION MODEL The Class A Model which will be used in the transport and diffusion of released effluents is a puf f-advection model which incorporates a horizontal wind field that can vary in time and space.
It is assumed in the puff-type model that the spread within a puff along the direction of flow is equal. to the spread in the lateral di rect ion (i.e., horizontal Guass ian Symmetry).
In the model, concen-tration averages are provioed by total integrated concentrations which are cal-culated by summing concentrations of individual elements for the grid points over which the puffs pass.
Features to be incorporated into the model include the use of predicted and edited primary or backup data, where appropriate, ter-rain effects, building wake ef fects, ground or clevated release mode, and special features used to describe site-specific meteorology.
Appropriate per-sistence and worst case meteorology will be used for initial releases until a meteorologist is notified to provide predictive data. -
JNSTRUMENTATION
. Table I shows the type and number of parameters to be measured at McGuire Nuclear Station af ter upgrading of the system.
The meteorological conditions present at McGuire Nuclear Station warrant the use of the basic described mete-orological variables.
These include wind speed and wind direction measured at high and low levels, delta temperature for stability classification, ambient air and dew point temperature, and precipitation.
_ DATA HANDLING The dose calculation system consists of a primary digital recording / storage system and a secondary analog chart recording system.
The meteorological vari-ables will be sampled at 60 second intervals for the digital system except for variables used to calculate signa theta, these will be sampled every 5 seconds.
Prior to meteorological data use or storage, the data will go through a series of edit checks which include range comparisons and data inter-comparisons to determine validity of data and whether backup data should be used.
Upon validation, the data will be placed on 12-hour recall for emergency efflu-ent dispersion modeling and dose calculation.
Validated data will also be stored on a magnetic medium as 1-hour average for future use and to meet the 90%
Joint annual data recovery requirements.
i l
DOSE ASSESSMENT METHODOLOGY The dose assessment methodology for McGuire consists of two separate calcula-tions. The first calculation is based on the amount of radioactivity that has been or is actually being released through the unit vent; the second calculation is based on a potential release using actual source term and design basis assumptions for containment Icakage.
To determine the dose from an actual release through the unit vent, both the concentration of isotopes in the unit vent and the unit vent flow rate must be known.
Unit vent grab sample analyses are used to determine the isotopic con-centrations of the release. When this information is not available, unit vent radiation monitors and their energy dependent sensitivities are used.
The flow rate is obtained from the unit vent flow rate monitor.
The combination of flow rate and isotopic concentrations is used to determine the actual release rate through the unit vent.
If substantial radioactivity is present in the containment, another calculation is performed. The calculation. provides the dose potential for a release based en the radioacitivity present in the containment.
A containment atmosphere sam-ple is used to determine the isotopic concentrations.
If this information is unavailabic, the containment building area radiation monitor is used to deter-mine the severity of the accident by comparison with design basis source terms.,..n
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The containment design leak rate is used unless factors, such as containment pressure, Indicate that another value is more realistic. The isotopic concen-trations combined with a containment leak rate provide a potential release rate of activity.
The dose model calculates both cumulative and projected doses.
Downwind concen-trations are determined by applying the relative atmospheric dispersion factor calculated by the meteorological model.
Proj ecte concentrations arc determined in one-hour increments up to a period of four hours. A forty year thyroid dose commitment and a whole body dose from exposure to a semi-infinite cloud are deter-mincd. The dose conversion factors are derived from Regulatory Guide 1.109 This dose assessment methodology provides the capability to calculate the dose from actual or potential releases following an accident.
Near real time radia-tion monitor readings and meteorological data are combined automatically to pro-vide timely, realistic dose calculations. However, the flexibility to manually input sample data is also provided. This model meets the guidance to NUREG-0654 Revision 1, Appendix 2 to provide the capability "to assess and monitor acutal or potential off-site consequences of a radiological emergency condition".
UPGRADED PHYSICAL SYSTEM DESCRIPTION The conceptual layout for the meteorological system is presented in Figure 1.
The sensors for the meteorological system are moented on existing towers. The signals will enter each Unit Operator Aid Computer (OAC) and the analog system.
The meteorological data will be stored on the OAC and can be transferred routinely or during an emergency situation to the Distributed Data Processor (DDP) via a manual transfer of a diskette from a OAC disk drive to a remote disk drive.
The Class A Model calculations will be made on the DDP system.
Routine meteorological data will be stored through the Distributed Data Processor System.
In the event of an emergency, it will have the capability to recall 12-hour meteorological data, radiation monitor data,. perform Class A Model calculations, and provide the inputs and calculated outputs to all appropriate site emergency response areas.
DETAILED DESCRIPTION OF SUBSYSTEMS Sensors to Operator Aid Computer The parameters to be measured by the meteorological system are listed in Tabic 1.
These meteorological sensors will meet the accuracies suggested in Regulatory Guide 1.23, Proposed Revision 1.
Signals from the meteorological system to the OAC (digital system) and analog charts will be cabled to the I.' ant.
Housing for signal conditioners and related instrumentation will be housed near the high level tower.
Uninterruptible power supplies will be provided to assure continuous operation of the meteorological system.
Sen-sors, conditioning equipment and instrumentation will have lightning protec-tion and will be heated where necessary to minimize effects of adverse envi-ronmental condi tions.
Signal cables will be shielded to minimize electrical Interference.
. i
Operator Aid Computer (OAC) to Distributed Data Procersor (DDP)
The process computer OAC system which is utilized for data collection con-sists of GE/Honeywell 4000 series equipment.
Inputs from the sensors (Figure 1) will be wired to the OAC and will be scanned according to guid-ance provided by Regulatory Guide 1.23, Proposed Revision 1.
Prede f ined metecrological inputs will be averaged for 15 minutes and the average will be stored for later use.
The OAC has bulk storage capability for 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> worth of 15 minGte averages.
Data retrieval from the OAC will be initiated at the Performance Typer in the computer room.
Each unit OAC is a backup for the other, capable of supplying the same required meteorological readings.
The data will either
be printed in a tabular format or stored on a floppy disk (diskette) which is designed for data exchange applications.
Upon output completion, the data will be removed from the OAC and additional data can be taken.
By means of a separate floppy disk reader attached to a data communications terminal in proximity to the OAC, the data will be transmitted to an off-line computer facility either on-site, or remote to the station.
Each set of data readings will be stored in an on-line data base for recall on demand.
The data will be subjected to validation procedures through both software and manual methods.
Immediately upon completion of the validation procc-dures, the data will be available to designated agencies through dial-in terminal facilities.
The data will further be available for both periodic archiving and for immediate processing by the puff-advection model.
Output from this model may also be made available to designated agencies in a read only mode.
The primary off-line data processing facility will be the station distribut-ed data processor (DDP).
First line backup to the station facility (See Figure 2) will be a similar DDP facility in the General Office in Charlotte, North Carolina. Additional backup facilities are evailable at each of the other nuclear stations.
The capability will also be provided to process this data in the Charlotte Corporate Computer Center.
~
QUALITY ASSURANCE in response to point 7, quality Assurance of Regulatory Guide 1.23, Proposed Revision 1, new equipment will be purchased from suppliers who have provided high quality, reliable equipment in the past.
Documentation concerning fabrica-tion and assembly of the components will be considered on a case-by-case basis as is normal for non-10CFR50 Appendix B items.
Tower modifications, cabling and computer hardware will be designed, procured and installed as a non-safety related system.
Surveillance during construction will be provided the same as for any other non-safety system.
Maintenance, calibration and repair procedures, and logs will be weallable at the s ite for inspect ion.
The procedures and logs will be designate 3 as site controlled documents.
Inventories of meteorological system spare parts, sensors anc components will be incorporated into existing company prc:cdurer.
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TABLE 1 McGuire Nuclear Station Meteorological Parameters of the Upgraded System Prima ry Existing 41 meter and High level wind speed and direction System 10 meter towers Low level wind speed and direction Delta temperature (stability)
Dry bulb temperature Precipitation Dew point O
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Figure 1.
McGuire Nuclear Station Generalized Met System Sensor to Computer Link 4
Sensors and Analog Chart Instrumentation System (located in Control Room) 1r 3r Computer Room Unit I g-Rad Unit 2 4-Rad 0AC Data OAC Data 1r 1r Floppy Disk Floppy Disk Drive Drive Diskette Remote Diskette
> Disk 4
Reader I
i ir I
DDP System ip Validated data, computer simulations I
(Class A Model)
Read Only Model for NRC TSC, EOF, CR and Other Duke and Other Designated Display Areas Agencies w
Permanent Storage 4
FIGURE 2
- NUCLEAR STATION OFFLINE COMPUTER SUPPORT T
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\\9600 BPS F
Charlotte General Office DDP 9600 BPS
-p 9600 BPS
[McGuire Catawba -
OAC OAC Oconee i
DDP Data Data DDP l
4 OAC '
0 Datag o
Notes j
1)_rdenotes dedicated cc:,munications 2)$ denotes 4800 BPS dial-up communications capability
- 3) Dedicated 9600 BPS communications to Corporate Computer Center from each station DDP schedule for 1982.
- 4) 9600 BPS network of DDP's scheduled for cross-connection (ie., as opposed to current " star" network) in 1983.
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