ML020240065
| ML020240065 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 01/17/2002 |
| From: | Katz P Constellation Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML020240065 (18) | |
Text
Peter E. Katz 1650 Calvert Cliffs Parkway Plant General Manager Lusby, Maryland 20657 410 495-4101 Nuclear Constellation Calvert Cliffs Nuclear Power Plant A Member of the Constellation Energy Group January 17, 2002 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION: Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos. 1 & 2; Docket Nos. 50-317 & 50-318 National Pollution Discharge Elimination System Permit No. MD0002399, Special Conditions P, Submittal of Copper Study In accordance with Section 3.2 of Appendix B, Environmental Protection Plan (Non-Radiological)
Technical Specifications, Attachment (1), the Calvert Cliffs Nuclear Power Plant National Pollution Discharge Elimination System Copper Study, as approved by the Maryland Department of the Environment, is provided.
Should you have questions regarding this matter, we will be pleased to discuss them with you.
Very truly yours, PEK/MJY/bjd
Attachment:
As stated cc: (Without Attachment)
R. S. Fleishman, Esquire H. J. Miller, NRC J. E. Silberg, Esquire Resident Inspector, NRC Director, Project Directorate I-1, NRC R. I. McLean, DNR D. M. Skay, NRC
/00
ATTACHMENT (1)
CALVERT CLIFFS NUCLEAR POWER PLANT NATIONAL POLLUTION DISCHARGE ELIMINATION SYSTEM COPPER STUDY Calvert Cliffs Nuclear Power Plant, Inc.
January 17,2002
Peter E. Katz 1650 Calvert Cliffs Parkway Plant General Manager Lusby, Maryland 20657 410 495-4101 Constellation S
Nuclear Calvert Cliffs Nuclear Power Plant A Member of the ConstellationEnergy Group December 20, 2001 Maryland Department of the Environment Water Management Administration 2500 Broening Highway Baltim-ore, Maryland 21224 RE: Calvert Cliffs Nuclear Power Plant NPDES Discharge Permit 99-DP-0187 (MD0002399)
Dear Sir:
In accordance with the requirements of the Maryland Department of the Environment NPDES Permit 99 DP-0 187, Special Conditions P, and the copper study plan approved by MDE in June 2000, I have enclosed the results of the copper study to determine compliance with state water quality standards at the Calvert Cliffs Nuclear Power Plant. If you have any questions regarding this information, please contact Brenda Nuse at (410) 495-4913.
SSincer lly, Peter E. Katz Plant General Manager Enclosures PEK:BDN cc: B.D. Nuse T.G. Ringger USNRC
Copper Study Calvert Cliffs Nuclear Power Plant Constellation Energy Group Preparedby:
Brenda D. Nuse Constellation Nuclear Calvert Cliffs Nuclear Power Plant 1650 Calvert Cliffs Parkway Lusby MD 20657 December 2001
Table of Contents Page In tro d u c tion ...................................................................................................................................... 3 O u tfa ll 0 0 1 ......................................................................................................................................... 4 O u tfa ll 0 02 .......................................................................................................................................... 6 C o n c lu s io n ...................... ................................................................................................................ 7 Attachm ent 1- Q uality Control Data ................................................................................. 8 - Comparison of Non-digested with Digested Analysis Results ...... 9 Attachm ent 3 - Unit 1 Discharge Total Copper ............................................................ 10 Attachm ent 4 - Unit 2 Discharge Total Copper ................................................................ 12 Attachm ent 5 - Intake Total Copper ..................................................................................... 14 2
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Introduction:==
The current discharge permit for the Calvert Cliffs Nuclear Power Plant, 99-DP-01 87 (MD0002399), became effective December 31, 1999. This permit contains a requirement to develop and implement a study plan for determining compliance with the state water quality standard for dissolved copper. The state water quality standard (COMAR 26.08.02.03-2) is less than 6.1 ppb copper for discharge to the Chesapeake Bay (estuarine water).
The study plan was developed and submitted to the Maryland Department of the Environment (MDE) in March 2000. The plan addresses Outfall 001 (circulating water discharge) and Outfall 002 (sumps and storm water discharge) separately. The plan for 001 involved a three-phase approach. The initial focus of the copper study looked at copper sampling and analysis methods and also looked at background levels in the Chesapeake Bay. If statistical analysis had indicated the water quality standards were not met at the end of the initial phase, then the chemical or biological translators would have been addressed in Phase II. If compliance with the water quality standards was not demonstrated after Phase II, then mixing zones would have been evaluated in Phase Ill.
The plan for Outfall 002 involved re-routing the discharge piping to combine the Outfall 002 flow with the Outfall 001 flow.
MDE approved the plan in June 2000.
3
Outfall 001 Sampling and Analysis - Phase 1:
Calvert Cliffs Nuclear Power Plant Chemistry Technicians collected all samples and performed all analyses.
Samples were collected weekly from the intake structure and both the Unit 1 and Unit 2 discharge conduits of Outfall 001. Samples were collected from July 27, 2000 through April 23, 2001. No samples were obtained from the Unit 2 discharge conduit after March 15, 2001, as the unit was not operating and there was no flow through the conduit. A comprehensive blank was run with each set of samples.
Samples were collected in polypropylene sample containers that were soaked with 0.5%
nitric acid for a minimum of twenty-four hours and rinsed with deionized water prior to use. Powder free gloves were worn to collect samples. All samples were collected using metal free sampling equipment. Samples were collected in triplicate from each sample point and immediately preserved with high purity nitric acid to a pH of less than 2.
All samples were analyzed for total copper in accordance with EPA Method 220.2 on a Perkin Elmer 11 OOB atomic absorption unit with a HGA-700 graphite furnace and AS-70 autosampler. Calvert Cliffs analyzed for total copper, as the permit specifies total copper analysis for Outfall 002. Total copper includes the soluble copper portion, thus is a more conservative value than the soluble copper analysis. The filtering process adds additional risk of contamination of the samples.
Each graphite furnace run included a five standard calibration curve from 2 - 20 ppb (0.002 - 0.020 mg/I) total copper using NIST traceable standards. Control standards were run after every ten samples and an influent sample was spiked to 6 ppb total copper and analyzed with each run (Att.1).
An NPDES inspection in December 2000 identified the copper samples were not digested prior to analysis as required by 40-CFR-136 - Guidelines establishingtest procedures for the analysis of pollutants. To determine the impact of digestion on the analysis of the intake and outfall samples, samples were analyzed both digested and without digestion.
Each sample was split, one aliquot was analyzed without digestion; the other aliquot was digested in accordance with "Methods for Chemical Analysis of Water and Wastes, 1979 and 1983, Section 4.1.3" prior to analysis. Data was collected for eight weeks (3/7/01' to 4/23/01). The results were recorded and the data sets compared by performing a two tailed Student's t Test at 95 % confidence level. The result of the two-tailed Student's t Test indicated the variance between the copper results from the sample aliquots with and without digestion was insignificant. (Att.2) 4
Outfall 001 Results:
All of the total copper results from the Unit 1 discharge conduit were less than 6.1 ppb (Att. 3). None of the analytical results for Unit 2 discharge conduit exceeded 6.1 ppb total copper (Aft. 4). No indication of re-entrainment is evident in the intake copper data (Att.5). Calculations using Calvert Cliffs radiological effluent data indicate the level of re entrainment is less than 15%.
5
Outfall 002 After the Outfall 001 copper study was completed, a modification to the plant piping was made. This modification combined the Outfall 002 discharge with the Outfall 001 discharge. This piping modification was completed on May 14, 2001.
The flow from the Outfall 001 is dependent on the number of circulating water pumps operating. Normally, there are twelve circulating water pumps operating at 200,000 gpm each. Even with only one circulating water pump operating (required even if both plants are not operating), the dilution ratio of the Outfall 002:Outfall 001 discharge would be 1:1327.
The impact on the copper concentration of the Outfall 001 discharge by re-routing the 002 flow into the 001 discharge is estimated by (CIV) -. V2= C2 using flow and concentration data obtained from samples taken from July 1997 to December 1999.
For Normal operation, with average copper concentration and full cooling water flow:
Where:
CI - average copper concentration of the 002 outfall (0.170 mg/I)
V1 - flow of the 002 outfall (0.217 MGD)
V 2 - flow of the 001 outfall (3456 MGD)
C2 - increase in copper concentration of the 001 outfall (mg/i) 0.170 mg/I x 0.217 MGD 002 flow - 3456 MGD 001 flow = 1.0E 5 mg/I copper For worst case conditions, with highest copper concentration and one circulating water pump:
Where:
C1 - maximum copper concentration of the 002 outfall (2.881 mg/I)
V1 - flow of the 002 outfall (0.217 MGD)
V 2 - minimum flow of the 001 outfall (288 MGD) 02 - increase in the copper concentration of the 001 outfall (mg/I) 2.881 mg/I x 0.217 MGD 002 flow ÷ 288 MGD 001 flow = 2.2E"3 mg/I copper Thus the modification combining the Outfall 002 and the Outfall 001 will not cause the Outfall 001 copper concentrations to exceed the water quality standard for copper.
6
Conclusion The samples collected from July 27, 2000 through April 23, 2001 indicate the discharge from Calvert Cliffs Nuclear Power Plant does meet the Water Quality Criteria for copper.
As the water quality standards were met at the end of the initial phase, Phase II and Phase III of the copper study were not required.
The addition of the Outfall 002 discharge flow to the Outfall 001 discharge will not cause the Outfall 001 copper concentration to exceed the water quality standard for copper.
7
- Quality Control Data S
Attachment 2 - Comparison of Non-digested with Digested Analysis Results Sample Date Not digested Digested All values < 2 are reported and calculated as = 2.
Intake 3/7/2001 2.5 2.5 3/7/2001 2.7 2.5 Statistics - Samples not digested prior to analysis Intake 2.6 # of observations 54 Intake 3/7/2001 2.7 2.6 AVG 2.21 Intake 3/12/2001 2 2.8 2.6 STD DEV 0.34 Intake 3/12/2001 Intake 3/12/2001 2.4 2.7 2 2 "T" test at 95% confidence level to identify outliers:
Intake 3/20/2001 2 2 Xhigh 3.2 Intake 3/20/2001 2 2 XIow 2 Intake 3/20/2001 2 2 Thigh 2.936 Intake 3/28/2001 2 2 Tlow 0.640 Intake 3/28/2001 2 2 critical T 3.158 Value corresponds to # of obs.
Intake 3/28/2001 2 2 Xhigh OUTLIER? TRUE True = NO outliers exist.
Intake 4/4/2001 4/4/2001 2 2 Xlow OUTLIER? TRUE False = outliers exist Intake Intake 4/4/2001 2 2 2.2 Two-tailed Student's t test at 95% confidence level:.
Intake 4/10/2001 2.1 2 %RSD 15.15 Intake 4/10/2001 2.3 2 Std. Dev.X 0.0457 Intake 4/10/2001 2 X std.exist chart 2.20 Intake 4/17/2001 2 2 2 "t" statisti 0.848 Intake 4/17/2001 2 2 "t" variate 2.01 Value corresponds to # of obs. - 1 Intake 4/17/2001 2 2 Bias TRUE True = bias does NOT exist.
Intake 4/23/2001 2 False = bias does exist Intake 4/23/2001 2 Intake 4/23/2001 2 2 Unit 1 3/7/2001 2.4 2.5 Unit 1 3/7/2001 2.6 2.2 Unit 1 3/7/2001 2.6 2.2 Unit 1 3/12/2001 2.7 2.2 3/12/2001 2.9 3 Statistics - Samples digested prior to analysis Unit 1 2.6 # of observations 53 Unit 1 3/12/2001 2 2 AVG 2.20 Unit 1 3/20/2001 2.6 2 2 STD DEV 0.30 Unit 1 3/20/2001 Unit 1 3/20/2001 2 2.2 2 2 "T" test at 95% confidence level to identify outliers:
Unit 1 3/28/2001 2 Xhigh 3.0 Unit 1 3/28/2001 2 2 Xlow 2 Unit 1 3/28/2001 2 2 Thigh 2.668 Unit 1 4/4/2001 2 2 TIow 0.651 Unit 1 4/4/2001 2 2 critical T 3.143 Value corresponds to # of obs.
Unit 1 4/4/2001 2 2 2 Xhigh OUTLIER? TRUE True = NO outliers exist.
Unit 1 4/10/2001 2 Xlow OUTLIER? TRUE False = outliers exist Unit 1 4/10/2001 2 4/10/2001 2 2 Outliers removed:
Unit 1 4/17/2001 2 2 4/10/01, > 20 Unit 1 Unit 1 4/17/2001 2 2 Unit 1 4/17/2001 2 2.3 Two-tailed Student's t test at 95% confidence level:
2 2 %RSD 13.72 Unit 1 4/23/2001 2 2 Std. Dev.X 0.0414 Unit 1 4/23/2001 2 2 X std.exist chart 2.20 Unit 1 4/23/2001 2.5 2.2 "t" statisti 0.091 Unit 2 3/7/2001 3/7/2001 3.1 2.2 "t" variate 2.008 Value corresponds to # of obs. - I Unit 2 3/7/2001 2.7 2.9 Bias TRUE True = bias does NOT exist.
Unit 2 False = bias does exist Unit 2 3/12/2001 3.2 2.7 Unit 2 3/12/2001 2.6 2.8 Unit 2 3/12/2001 2 2.9 Average: 2.2 2.2 9
Attachment 3 - Unit 1 Discharge Total Copper Date Sample results, ppb All values < 2 are reported and calculated as = 2.
7/27/2000 2 7/27/2000 2 # of obs (average of 3 samples) 38 7/27/2000 2 AVG 2.3 8/3/2000 2 STD DEV 0.61 8/3/2000 2 8/3/2000 2 "T" test at 95% confidence level to identify outliers:
8/9/2000 2 Xhigh 5.2 8/9/2000 2 Xlow 2 8/9/2000 2 Thigh 4.81 8/15/2000 2 Tlow 0.49 8/15/2000 2 critical T 3.003 Value corres. to # of obs.
8/15/2000 2 Xhigh OUTLIER? FALSE True = NO outliers exist.
8/22/2000 2 Xlow OUTLIER? TRUE False = outliers exist 8/22/2000 2 Outliers removed: None, all results < 6.1 ppb 8/22/2000 2 8/28/2000 2 Date Average 8/28/2000 2 7/27/2000 2 8/28/2000 2 8/3/2000 2 9/7/2000 2 8/9/2000 2 9/7/2000 2 8/15/2000 2 9/7/2000 2 8/22/2000 2 9/12/2000 2 8/28/2000 2 9/12/2000 2 9/7/2000 2 9/12/2000 2 9/12/2000 2 9/21/2000 2 9/21/2000 2.3 9/21/2000 3 9/30/2000 5.2 9/21/2000 2 10/13/2000 2 9/30/2000 11.7 10/19/2000 2.6 9/30/2000 2 10/25/2000 2 9/30/2000 2 11/3/2000 2 10/13/2000 2 11/8/2000 2 10/13/2000 2 11/16/2000 2 10/13/2000 2 11/21/2000 2 10/19/2000 2 12/1/2000 2 10/19/2000 3.3 12/6/2000 2 10/19/2000 2.4 12/15/2000 2 10/25/2000 2 12/20/2000 2 10/25/2000 2 12/29/2000 2.8 10/25/2000 2 1/4/2001 2.2 11/3/2000 2 1/10/2001 2.3 11/3/2000 2 1/17/2001 2 11/3/2000 2 1/25/2001 3 11/8/2000 2 1/31/2001 2.6 11/8/2000 2 2/8/2001 3.1 11/8/2000 2 2/15/2001 3.2 11/16/2000 2 2/22/2001 3.1 11/16/2000 2 3/7/2001 2.3 11/16/2000 2 3/12/2001 2.6 11/21/2000 2 3/20/2001 2.1 11/21/2000 2 3/2812001 2 11/21/2000 2 4/4/2001 2 12/1/2000 2 4/10/2001 2 12/1/2000 2 4/17/2001 2.1 12/1/2000 2 4/23/2001 2 12/6/2000 2 12/6/2000 2 12/6/2000 2 10
Attachment 3 - Unit I Discharge Total Copper 12/15/2000 2 12/15/2000 2 12/15/2000 2 12/20/2000 2 12/20/2000 2 12/20/2000 2 12/29/2000 2.6 12/29/2000 3 12/29/2000 2.8 1/4/2001 2 1/4/2001 2.5 1/4/2001 2 1/10/2001 2.4 1/10/2001 2.2 1/10/2001 2.4 1/17/2001 2 1/17/2001 2 1/17/2001 2 1/25/2001 3 1/25/2001 3 1/25/2001 3 1/31/2001 2 1/31/2001 2.8 1/31/2001 2.9 2/8/2001 2.9 2/8/2001 3.3 2/8/2001 3.1 2/15/2001 3.2 2/15/2001 3.1 2/15/2001 3.2 2/22/2001 3.1 2/22/2001 3 2/22/2001 3.1 3/7/2001 2.5 3/7/2001 2.2 3/7/2001 2.2 3/12/2001 2.2 3/12/2001 3 3/12/2001 2.6 3/20/2001 2 3/20/2001 2 3/20/2001 2.2 3/28/2001 2 3/28/2001 2 3/28/2001 2 4/4/2001 2 4/4/2001 2 4/4/2001 2 4/10/2001 2 4/10/2001 2 4/10/2001 2 4/17/2001 2 4/17/2001 2 4/17/2001 2.3 4/23/2001 2 4/23/2001 2 4/23/2001 2 11
Attachment 4 - Unit 2 Discharge Total Copper Date Sample results, ppb All values < 2 are reported and calculated as = 2.
7/27/2000 2 7/27/2000 2 # of obs (average of 3 samples 32 7/27/2000 2 AVG 2.3 8/3/2000 2 STD DEV 0.51 8/3/2000 2 8/3/2000 2 "T" test at 95% confidence level to identify outliers:
8/9/2000 2 Xhigh 3.7 8/9/2000 2 Xlow 2 8/9/2000 2 Thigh 2.686 8/15/2000 2 Tlow 0.663 8/15/2000 2 critical T 2.938 Value corres. to # of obs.
8/15/2000 2 Xhigh OUTLIER? TRUE True = NO outliers exist.
8/22/2000 2 Xlow OUTLIER? TRUE False = outliers exist 8/22/2000 2 Outliers removed: None, all results < 6.1 ppb 8/22/2000 2 8/28/2000 2 Date Average 8/28/2000 2 7/27/2000 2 8/28/2000 2 8/3/2000 2 9/7/2000 2 8/9/2000 2 9/7/2000 2 8/15/2000 2 9/7/2000 2 8/22/2000 2 9/12/2000 2 8/28/2000 2 9/12/2000 2 9/7/2000 2 9/12/2000 2 9/12/2000 2 9/21/2000 2.7 9/21/2000 3.5 9/21/2000 3.6 9/30/2000 2.7 9/21/2000 4.2 10/13/2000 2 9/30/2000 2 10/19/2000 3.0 9/30/2000 2 10/25/2000 2 9/30/2000 4.1 11/3/2000 2 10/13/2000 2 11/8/2000 2 10/13/2000 2 11/16/2000 2 10/13/2000 2 11/21/2000 2 10/19/2000 2 12/1/2000 2 10/19/2000 2 12/6/2000 2 10/19/2000 5.1 12/15/2000 2 10/25/2000 2 12/20/2000 2 10/25/2000 2 12/29/2000 2.8 10/25/2000 2 1/4/2001 2.2 11/3/2000 2 1/10/2001 2.4 11/3/2000 2 1/17/2001 2 11/3/2000 2 1/25/2001 2.8 11/8/2000 2 1/31/2001 2.2 11/8/2000 2 2/8/2001 2.8 11/8/2000 2 2/15/2001 3.4 11/16/2000 2 2/22/2001 3.7 11/16/2000 2 3/7/2001 2.4 11/16/2000 2 3/12/2001 2.8 11/21/2000 2 11/21/2000 2 11/21/2000 2 12/1/2000 2 12/1/2000 2 12
Attachment 4 - Unit 2 Discharge Total Copper 12/1/2000 2 12/6/2000 2 12/6/2000 2 12/6/2000 2 12/15/2000 2 12/15/2000 2 12/15/2000 2 12/20/2000 2 12/20/2000 2 12/20/2000 2 12/29/2000 3.1 12/29/2000 2.6 12/29/2000 2.6 1/4/2001 2 1/4/2001 2.4 1/4/2001 2.3 1/10/2001 2.4 1/10/2001 2.4 1/10/2001 2.4 1/17/2001 2 1/17/2001 2 1/17/2001 2 1/25/2001 2.9 1/25/2001 2.7 1/25/2001 2.9 1/31/2001 2 1/3112001 2 1/31/2001 2.5 2/8/2001 2.7 2/8/2001 3 2/8/2001 2.8 2/15/2001 3.2 2/15/2001 3.3 2/15/2001 3.6 2/22/2001 3.4 2/22/2001 4.2 2/22/2001 3.5 3/7/2001 2.2 3/7/2001 2.2 3/7/2001 2.9 3/12/2001 2.7 3/12/2001 2.8 3/12/2001 2.9 13
Attachment 5 - Intake Total Copper Date Sample results, ppb All values < 2 are reported and calculated as = 2.
07127/00 2 07/27/00 2 # of obs (average of 3 samples) 38 07/27/00 2 AVG 2.2 08/03/00 2 STD DEV 0.36 08/03/00 2 08/03/00 2 "T" test at 95% confidence level to identify outliers:
08/09/00 2 Xhigh 3.1 08/09/00 2 Xlow 2 08/09/00 2 Thigh 6.218 08/15/00 2 Tlow 0.608 08/15/00 2 critical T 3.014 Value corres. to # of obs.
08/15/00 2 Xhigh OUTLIER? FALSE True = NO outliers exist.
08/22/00 2 Xlow OUTLIER? TRUE False = outliers exist 08/22/00 2 Outliers removed: None, all results < 6.1 ppb 08/22/00 2 08/28/00 2 Date Average 08/28/00 2 07/27/00 2 08/28/00 2 08/03/00 2 09/07/00 2 08/09/00 2 09/07/00 2 08/15/00 2 09/07/00 2 08/22/00 2 09/12/00 2 08/28/00 2 09/12/00 2 09/07/00 2 09/12/00 2 09/12/00 2 09/21/00 2.7 09/21/00 3.1 09/21/00 3.1 09/30/00 2.4 09/21/00 3.4 10/13/00 2 09/30/00 2 10/19/00 2 09/30/00 3.2 10/25/00 2 09/30/00 2 11/03/00 2 10/13/00 2 11/08/00 2 10/13/00 2 11/16/00 2 10/13/00 2 11/21/00 2 10/19/00 2 12/01/00 2 10/19/00 2 12/06/00 2 10/19/00 2 12/15/00 2 10/25/00 2 12/20/00 2 10/25/00 2 12/29/00 2.5 10/25/00 2 01/04/01 2.4 11/03/00 2 01/10/01 2.5 11/03/00 2 01/17/01 2 11/03/00 2 01/25/01 2.9 11/08/00 2 01/31/01 2.4 11/08/00 2 02/07/01 3.0 11/08/00 2 02/15/01 3.0 11/16/00 2 02/22/01 3 11/16/00 2 03/07/01 2.5 11/16/00 2 03/12/01 2.6 11/21/00 2 03/20/01 2 11/21/00 2 03/28/01 2 11/21/00 2 04/04/01 2 12/01/00 2 04/10/01 2 12/01/00 2 04/17/01 2 12/01/002 04/23/01 2 12/06/00 2 12/06/00 2 12/06/00 2 14
Attachment 5 - Intake Total Copper 12/15/00 2 12/15/00 2 12/15/00 2 12/20/00 2 12/20/00 2 12/20/00 2 12/29/00 2.5 12/29/00 2.4 12/29/00 2.5 01/04/01 2 01/04/01 3.2 01/04/01 2 01/10/01 2.5 01/10/01 2.3 01/10/01 2.6 01/17/01 2 01/17/01 2 01/17/01 2 01/25/01 2.4 01/25/01 3 01/25/01 3.2 01/31/01 2 01/31/01 2.8 01/31/01 2.5 02/07/01 2.9 02/07/01 3 02/07/01 3 02/15/01 3 02/15/01 3.2 02/15/01 2.9 02/22/01 3.1 02/22/01 2.9 02/22/01 3 03/07/01 2.4 03/07/01 2.5 03/07/01 2.6 03/12/01 2.6 03/12/01 2.6 03/12/01 2.7 03/20/01 2 03/20/01 2 03/20/01 2 03/28/01 2 03/28/01 2 03/28/01 2 04/04/01 2 04/04/01 2 04/04/01 2 04/10/01 >20 04/10/01 2 04/10/01 2 04/17/01 2 04/17/01 2 04/17/01 2 04/23/01 2 04/23/01 2 04/23/01 2 15