05000305/FIN-2007006-14
Finding | |
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| Title | Emergency Diesel Generator Rooms Cooling Fans Testing Deficiencies |
| Description | The inspectors identified an unresolved item regarding the ability of the EDG Room Cooling Fan to maintain the room below its design temperature. Description: While reviewing the EDG room cooling calculations, the inspectors noted the design flow rate for the EDG Room Cooling fans was 60,000 CFM and the calculated required flow rate for these fans was 60,303 CFM in order to maintain the room at its design temperature of 120oF. The inspectors had several concerns
The inspectors determined that during a preoperational test, the licensee measured the flow velocity of the EDG Room Cooling fan and multiplied the velocity by the cross sectional area of the duct to determine the fan flow rate. During the pre-operational test, it was determined that the cross section area of the fan's duct was 18.6 square feet, and based on this value, the flow rate was calculated to be 60,200 CFM using anemometer readings and 59,300 CFM using velometer readings. However, the inspectors reviewed the manufacturer's certified performance test and noted that the cross sectional area of the fan's circular duct (54 inch diameter) was 15.9 not 18.6 square feet. In addition, the35 Attachment licensee calculated the cross sectional area of the duct by multiplying three linear dimensions (in feet) to arrive at a square feet answer During the inspection, the licensee confirmed that the actual cross sectional area of the circular duct was 15.9 square feet. Using the correct cross sectional area and the originally measured flow velocities, the licensee recalculated the flow rate using the anemometer readings, was 51,468 CFM and using the velometer readings, was 50,689 CFM. These values were significantly lower than the original assumed design flow rates The licensee did not account for a very large instrument uncertainty associated with the readings. The velometer readings which were later averaged, varied from 2900 to 3600 feet per minute, a difference of 24 percent (with respect to the smaller value). The anemometer readings which were later averaged, varied from 3050 to 3456 feet per minute, a difference of 13 percent (with respect to the smaller value). The original calculation used an EDG heat load assuming 2600 kW rating instead of the heat load assuming 2864.kW rating. Following discovery, the licensee initiated a CAP and reperformed the calculation using 54,000 CFM (10 percent lower than the design flow rate of 60,000 CFM) as well as using the a new heat load based on the correct diesel kW rating. The licensee planned to perform EDG Room volumetric flow testing (Work Orders 07-2512 and 07-2513) to confirm the calculational results. This issue is considered unresolved pending review of test results. (URI 05000305/2007006-14 (DRS)). |
| Site: | Kewaunee  |
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| Report | IR 05000305/2007006 Section 1R21 |
| Date counted | Jun 30, 2007 (2007Q2) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.21 |
| Inspectors (proximate) | G Skinner M Yeminy R Langstaff S Burgess Z Falevits A Dahbur A Stone C Brown F Trapd Mcneilr Ruiz J Jandovitz J Cassidy C Brown C Moore M Kunowski P Higgins S Burton K Barclay R Russell |
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Finding - Kewaunee - IR 05000305/2007006 | |||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Kewaunee) @ 2007Q2
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