ML20217N561
| ML20217N561 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 04/24/1998 |
| From: | Barron H DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9805050373 | |
| Download: ML20217N561 (6) | |
Text
h Duke Power Company A l>nuk Ewy Ccum gg",Nulear Sta.:on
, r., n,,
12700 Hagers Ferry Rd.
Huntersville, NC 28078-9340 H. B. Barron Mce President, McGuin (704) 875-4800 OFFICE l
Nwlear Ger.tration Department (704) 8754809ux April 24,1998 U.S. Nuplear Regulatory Commission Attentio'n: Document Control Desk Washington, D.C. 20555
Subject:
McGuire Nuclear Station, Units 1 and 2 i
Docket Nos. 50-369 and 50-370 -
Response to Questions Regarding Proposed Technical Specification (TS) Amendment TS 5.5 - Meteorological Tower Location By letter dated March 3,1998, McGuire Nuclear Station submitted the subject proposed Technical Specification Amendment. During a telephone conference earlier this month, the NRC staff requested additional information regarding this proposed Technical Specification Amendment. Attached is the response to these questions.
This response contains regulatory commitments.1) Design Basis Calculations and UFSAR will be reviewed for any needed changes once the data are collected from the new meteorological tower location and correlated with the data from the old meteorological tower location. 2)
Annual dose reports and Offsite Dose Calculation Manual will be revised as necessary if the data trends from the new meteorological tower location change.
Please contact P.T. Vu at (704) 875-4302 regarding this response.
Very truly yours, H.B. Barron
{
Attachment
\\
Y 9805050373 900424 PDR ADOCK 05000369 P
US NRC
- April 24,1998 Page 2 xc:(w/ attachment)
L.A.- Reyes Administrator, Region II
)
U.S. Nuclear Regulatory Commission 101 Marietta St., NW, Suite 2900
! Atlanta,'GA.- 30323 F. Rinaldi Senior Project Manager Office of U.S. Nuclear Reactor Regulation One White Flint North,' Mail Stop 14E21-Washington, D.C. 20555 S.M. Shaeffer NRC Senior Resident Inspector McGuire Nuclear Station R.M. Fry, Director -
Division of Radiation Protection; State of North Carolina
- 3825 Barrett Drive Raleigh, N.C. 27609-7221 i
bxc: (w. attachment)
- ELL (EC050)
~ NSRB (EC05N)
N. Osburn(MG0lWC)
B. Nesbitt (MG01MO).
- M. Kinley (MG03C4)
B. Gragg (MG05EE)
L.B. Jones (EC050)
C.D. Ingram (EC07F)
P.T. Vu (MG01RC) l 1
h
.i
US NRC Attachment April 24,1998 Page 1 of 3 QUESTIONS AND RESPONSE REGARDING RELOCATION OF THE MCGUIRE METEOROLOGICAL TOWER l
1.
Have meteorological data from the current and new tower locations been collected and correlated? If so, describe the periods and parameters compared and results of the correlation. If not, describe plans to assure that data collected at the new location can and will be correlated with the historical meteorological data upon which the plant was designed and has been operated.
Meteorological data has not previously been collected from the proposed new tower location; however, the data that will be collected from the new tower locatinn. upon NRC's approval of
~ this proposed Technical Specification Amendment, will be used ' e amparing with the data from the old tower location. Although annual meteorological data.. nnally varies from year to year, five-year climatologies or longer term historical data derived from the proposed site should not differ from the historical data taken from the existing meteorological tower. Design Basis Calculations and UFSAR will be reviewed for any needed changes once the new data are collected and correlated.
The sector specific relative air concentrations (X/Q) and deposition (D/Q) values used in dose calculations for the Offsite Dose Calculation Manual (ODCM) are based on meteorological data from the existing tower for a ground level release. In addition, effluent dose reports are also submitted to the NRC annually, based on annualjoint frequency distributions of stability class, 10m wind direction, and 10m wind speed. If meteorological data trends for 10m wind speed, 10m wind direction, and stability class change with the new tower, then this will be identified in preparing the annual dose reports, and the ODCM will be revised.
Design Basis calculations use a worst case dose for potential accident scenarios and typical dose from routine operations. To determine X/Q's, onsite meteorological data may be input to X/Q models as a joint frequency distribution, or conservative assumptions are used from the appropriate Regulatory Guides, independent of onsite meteorology (e.g. RG 1.4 for Loss of Coolant Accident). In many cases, the calculations do not use a direction-specific X/Q to determine dose; instead, the worst case X/Q is applied to determine a worst case dose.
US NffC Attachment April 24,1998 Page 2 of 3 2.
In Attachment III of a March 3,1998 letter from Duke Power Company regarding the proposed Technical Specification (TS) Amendment TS 5.5 on meteorological tower location, it is stated that the ANSI /ANS-2.5-1984 distance requirement of 10 times an obstruction height will be met. The examples given seem to be relative to the height of measurement (i.e.,10m and 60m) versus the height of the potential obstruction. Please confirm that this means any obstructions are at least 10 times their height from the proposed meteorological tower, as opposed to being at least 10 times away from the tower with respect to the height of measurement.
Yes. All structures are at a dinace of at least 10 times their height from the proposed new tower location. Trees were cut around the proposed site to meet the 10x rule. Distance to and heights of the plant structures and visitor's center (closest building) were verified by surveyors to meet the 10x rule.
Apnmrimate Distances Stmeture's Height McGuire Site Structure Above New Tower's 10x Distance Actual Distance Base Reauirement Closest Reactor Buildine 134 feet 1340 feet 1350 feet Energy Explorium 25 feet 250 feet 783 feet Visitor Center
1 US NRC Attachment
- April 24,1998 Page 3 of 3 3.
The new tower would be located near the discharge canal. Aside from the distance recommendation of 10 times an obstruction height referenced above, what other considerations were included in the selection of the proposed tower location versus another location?
Two other sites were evaluated prior to selection of the proposed site. One site was on the South-West side of Lake Norman near the Cowans Ford Dam. This location had an open exposure, but did not provide a large enough area to erect the tower with necessary guy lines for the structure. This location was also in an unsecured area. A second location was considered on the South side of the plant property near the Garage and Switchyard. However, the topography in this area slopes down into the river valley and would not provide an open exposure for siting the -
tower.
The proposed site was selected as most suitable for the following reasons. Security is enhanced by locating the tower close to the plant. This site is the closest of the three sites considered, and is' subject to routine security patrols. The site has an open exposure to Lake Norman and a straight line of sight to McGuire's Unit Vents. Although trees along the lake shore had to be cleared. the land is relatively flat, with no hills affecting the micro-scale flow around the site.
The main effect from the discharge canal on the site would be local fogging along the canal on cool mornings. But since dew point temperature or relative humidity will not be measured, this is not a concern. Fogging from the discharge canal will not affect the measurements being taken (wind speed, wind direction, temperature, delta-T, precipitation). Ambient meteorology in the vicinity of McGuire is dominated by the presence of Lake Norman; this is also the case for the proposed MET tower site, located between the plant and the Lake. Any heat dissipation from the discharge canal will not affect the 10m and 60m temperature measurements.
.