ML20249B628

Safety Evaluation Accepting 980303 Request to Review & Approve Proposed Change to Plant,Units 1 & 2 TS Re Relocation of Meteorological Tower

ML20249B628
Person / Time
Site:	McGuire, Mcguire
Issue date:	06/12/1998
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20249B625	List: ML20249B624 ML20249B628
References
NUDOCS 9806230390
Download: ML20249B628 (2)

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E AFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGUC.ATION RELATED TO FACILITY OPERATING LICENSE NOS. NPF.9 AND NPF-17 DUKE POWER COMPANY MCGUIRE NUCLEAR STATION 3 UNITS 1 AND 2 DOCKET NOS,50 369 AND 50 270 Introduction By letter dat6d March 3,1998, the licensee requested the staff to revicw and approve a proposed change to the McGuire Nuclear Station, Units 1 and 2, Technical Specifications concerning relocation of the meteorological tower. The location at which the meteorological tower is currently sited is planned to be used as a plant construction site.

Evaluation The licensee plans to remove the current meteorological tower from its location West of

' the reactor plant compier, and construct a new tower at a location generally North of the plant complex on a strip of land between Lake Norman and the plant discharge canal.

To obtain meteorological information required for a valid estimate of atmospheric diffusion in the vicinity of a nuclear power plant site, the meteorological instruments should be sited to adequately represent overall site area conditions and minimize possible influences from local features. The licenses has considered several locations prior to selection of the proposed location. One location is in an open area, but does not d provide adequate space for placement of guy lines needed to secure the tower and is not in a secured area. A second location is in an area where topography slopes down into a river valley and could be subject to localized air flows.

The proposed tower location is generally North of the plant complex on a strip of land between Lake Norman and the plant discharge canal. The licensee has stated that this location meets the guidelines of Section C.2," Siting of Meteorologicalinstruments," of

. Regulatory Guide 1.23,"Onsite Meteorological Programs." The new tower will be sited at approximately the same elevation as finished plant grade and in an area where plant structures will have little or no influence on the meteorological measurements. As a result of removing trees along the shore of Lake Norman, the tower will be sited in an ,

open area that is at least 10 obstruction heights away from natural or man-made obstruction.s. This relatively flat area has an exposure to Lake Norman whose presence dominates the ambient meteorology in the McGuire site vicinity. At the new location the tower will also be further away from possible influences of plant buildings and the Cowans Ford Dam. While the tower will be near the plant discharage canal, the licensee has determined that the canal should not affect the meteorological measurements. The proposed location is also subject to routine security checks.

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The licensee has n N .

ormed a q.:antitative assessment of the potential effects of possible micro scQe conditions on the meteorological measurements, but has committed in a Mggia,1998 letter from H. B. Barron to collect concurrent meteorological data for a short period of time. This time is estimated to be between 1 and 15,1998, when the new tower becomes operational and prior to removal of the current tower to facilitate the planned construction work. While it would be desirable to collect concurrent data for a longer period of time, the licensee has stated that this is the longest period possible given the instrument acquisition, tower N8g, placement and construction schedules. The planned period of cl measurements will allow a limited co,mp ison , flecting dium s By a letter dated April 24,1 8, the licensee has committed to compare and correlate historical data with quarte y and annual data periods collected from the new tower, 41 review the need for revis}n design bas:a calculations, the FSAR and ODCM and make '

updates as appropriate. a minimum, the licensee will review one year of data for p!

representativeness of a h hourly data record collected from the new tower and g' compare the data from the new tower with historical data with respect to time of day and season. The licensoe will provide a report to the NRC describing the review performed y-and identify and discuss the probable cause and significance of any apparent anomolles d or differences between measurements taken on the two towers. Should it appear that data collected at the new tower location are not temporally or spacially representative of i the overall site meteott.iogy, the licensee will institute remedial measures.

Conclusion The licensee has made commitments to compare and correlate data collected at the current and new tower locations and, if appropriate, to make changes to design basis calculations, the FSAR and ODCM. These commitments are being relied uppn to assure that the new tower location can consistently provide data that are adequately representative of overall site area conditions and update the McGuire dose calculations, if needed. Based upon these considerations the staff has concluded that the proposed changes to the McGuire Technical Specifications to move the location of the meteorological tower are acceptable.

Principal Contributor: Leta Brown Date: June 12,1998 I 0

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