ML20079N230
| ML20079N230 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 12/31/1987 |
| From: | Dan Orr NORTHERN STATES POWER CO. |
| To: | |
| References | |
| RTR-NUREG-1437 AR, NUDOCS 9111110121 | |
| Download: ML20079N230 (14) | |
Text
,.
MONTICELLO NUCLEAR GEN l'LANT i
ATTACitMENT 2 e
f MONTICELLO NUCLEAR GENERATING PLANT T"VIRONMENTAL MONITORING PROGRAM
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1987 ANNUAL REPORT I-WATER MONITORING SUMl'ARY (Physical Parameters) f Prepared by:
D. J. Orr Environmental and Regulatory Activities Department Northern States Power Company 1
9111110121 871231 PDR NUREQ 1437 C POR
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1987 MONTICELLO WATER MONITORING
SUMMARY
(PHYSICAL PARAMETER)
The Monticello Nuclear Generating Plant (MNGP) had seven outages during 1987 (Table 1).
These outages accumulated to approximately 72 days of non-production time.
MNGP's on-line performance for 1987 was 80 percent.
Corresponding on-line operation for MNGP from 1979 through 1986 is 98, 79, 72, 65, 96, 9,
92 and 79 percent respectively.
MNGP was down from February 4,
1984 until January 19, 1985 for major re-piping and refueling.
Data are collected and tabulated hourly by the MNGP computer, which monitored plant intake (cfs), river flow (cfs), ambient water temperature (degrees F),
and discharge canal temperature (degrees F).
These data were transformed into weekly averages and are listed in Table 2 and displayed on Figures 1 and 2.
The MNGP computer that monitors these parameters was down periodically during the refueling outage from October into December so some data for that period was estimated.
Average weakly river discharge (flow) in 1987 was 4,215 cfs.
The 40-year monthly average from U.S. Army Corps of Engineers data was 4,400 cfs while the average monthly flow at Monticello from 1973 to 1987 was 6,408 cfs (Table 3).
Figure i
3 compares graphically 1987 flow data with the 15-year monthly mean flows.
Average monthly flows in 1987 were lower than the mean values every month except January, in contrast to 1986 when monthly flows were above the mean values every month except March.
Two major flow peaks occurred, one in March and one in June (Figure 1).
On 28 March 1987 river flow reached 9,099 cfs.
The flow dropped below 3,000 cfs by early May then began increasing and peaked on 27 May at 11,832 cfs.
Lack of snow cover in the winter of 1986-1987 yielded minimal spring run-off resulting in reduced flow rates which persisted into the summer due below average 3
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precipitation in the late spring.
The minimum river dis-charge of 1,706 cfs occurred on 18 July 1987.
I 1
The average withdrawal rate while the plant was operating was 489 cfs in 1987.
Ambient and discharge water temperatures are plotted in Figure 2.
Ambient water temperature rose above 33 degrees F for the season on 11 March and dropped below that level for the season on 12 December.
Maximum ambient water temperature occurred on July 31 at 84.4 degrees F (compared to 78.5 P on July 20, 1986).
Winter discharge temperatures during plant operation averaged approximately 67 degrees F, which is a a T of 35 degrees F.
Maxinum discharge temperature of 94.6 degrees F occurred in July; the 6 T at this time was 10.2 degrees F.
Discharge temperatures throughout the period of cooling tower operation averaged 85.6 degrees F,
with a mean A T of 11.1 degrees F over ambient river water temperatures.
To define the area affected by MNGP's thermal plume, temperature surveys were conducted on a six-kilometer reach of the Mississippi River downstream from the plant.
These surveys wete conducted in March, May, and August of 1987 and January of 1988.
The winter survey was conducted in January 1988 because the plant was not in operation from October through mid-December.
The warmest water during each of these surveys was on the Wright County side of the river.
Figure 4 g
illustrates this effect for the month of January.
R At MNGP's outfall structure, the highest A T was recorded in
- January, which was 26 degrees F above ambient river water temperature.
Deviations from ambient water temperature at the outfall structure in March, May, and August were 23 degrees F, 22 degrees F, and 9 degrees F, lespectively.
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Table 1.
1987 Monticello off-Line Time i
Date Off Date On January 9 January 12 January 21 February 18 February 21 February 24 June 28 June 29 October 22 December 1B l
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Table 2.
Monticello Water Honitoring Summary (Physical Firameters)
Mean Weekly Values Plant Ambient Dicharge Discharge Intake River Canal Week Starting (cfs)
(cfs)
Temp ( F)
Temp (OT)
December 29 5,988 554.3 32.1 69.6 January 4
5,559 446.3 32.2 61.6 11 5,260 494.0 32.2 44.5 18 4,772 557.7 32.2 45.6 25 4,592 562.7 32.2 70.0 February 1
4,468 529.7 32.3 69.6 8
4,457 550.6 32.3 71.1 15 4,467 458.0 32.4 53.7 1
22 4,354 494.1 32.6 62.8 March 1
4,398 515.5 34.6 73.8 f
8 5,394 480.4 34.1 73.3 15 4,859 464.8 36.3 74.8 22 7,334 50F.0 40.0 74.4 29 7,874 534.3 37.8 66.1 April 5
6,093 549.7 48.0 78.5 12 5,408 554.6 54.6 84.8 19 4,577 553.0 59.3 87.2 26 3,916 563.6 59.8 88.8 May 3
3,274 558.7 61.8 90.6 10 2,763 565.0 66.1 89.7 17 3,740 575.8 63.4 84.4 24 10,456 618.4 63.5 89.0 31 9,867 633.3 69.4 82.0 Jun:
7 5,786 623.1 71.4 82.5 14 3,148 622.4 75.4 87.1 21 2,973 571.0 76.0 84.8 28 2,612 590.7 74.2 82.8 July 5
2,020 626.4 77.8 86.8 12 1,955 602.8 76.0 85.9 h
19 2,670 627.3 80.1 91.0 P
26 4,561 640.4 82.2 92.8 August 2
4,441 637.0 79.1 88.1 9
3,361 631.7 75.5 86.8 16 3,153 623.3 75.1 84.0 23 2,932 613.4 69.1 80.5 30 2,517 605.6 67.6 85.8 R
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t Table 2.
(Continued) 1 Plant Ambient Dicharge Discharge Intake River Canal Week Starting (cts)
(cfa)
Temp (OT)
Temp (OT)
September 6
2,443 604.7 69.1 83.6 13 2,329 593.6 64.6 88.9 20 3,313 597.8 61.8 85.4 27 3,584 594.4 60.1 83.2 October 4
3,187 584.3 50.6 73.4 11 3,335 381.4 47.0 69.6 18 3,293 448.3 44.4 55.6 25 3,609 94.0 41.3 43.2 November 1
3,531 0.0 42.6 8
3,624 29.3 41.5 15 3,655 13.3 33.5 36.8 l
22 3,597 18.5 33.8 36.4 29 3,757 22.7 32.5 35.1 December 6
3,512 51.6 32.7 35.7 13 3,548 332.0 32.1 35.6 20 2,845 547.0 32.0 70.5 Average 4,215 489.4 52.3 73.6
- Computer link to probe down.
7
s Table 3.
Misalesippi River et Monticetto, Minnesota Monthly Average Elver Discharge (cfs).
1971 1974 1975 1976 197' 1978 1979 1980 1981 1952 1983 1984 1985 1986 1957
!L Janvery 3755 3787 6908 3459 1295 5800 4830 455T 2788 8120 5120 5536 2000 5808 5135 4993 February 3644 3875 6297 3763 1754 4800 5469 4856 2808 6200 48T0 6610 6873 5414 4436 4778 werch 11132 3796 5620 7796 3341 T500 6352 4653 3023 6030 9970 6813 9164 6211 5783 6478 AprII 6361 11513 18122 11700 3350 10500 17161 9138 55TC 19560 8090 9601 9454 22400 5396 11196 May 4678 16387 26355 3815 2202 7000 17500 3611 5716 17960 5150 9307 14938 23550 5182 1103T l
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June 4038 12370 9323 1903 2475 6500 9028 3698 6572 8870 8380 15270 11791 10451 4990 7711 DD July 2189 3918 12137 1852 2323 5500 9313 2008 5130 5560 8590 5T06 10208 8504 2684 STO8 August 4340 3458 3654 1203 1275 6000 4818 2036 5045 3160 4510 2579
'528 8035 3476 4094 September 2771 1615 3325 1952 3420 6500 3919 4105 3592 3630 3770 2310 8994 15442 2759 4480 october 12289 1719 3133 1151 5617 4700 296T 3522 8399, 10720 4920 9146 9498 12128 3375 6219 movember 7418 4171 3625 1331 6783 3996 6974 2755 6602 7420 5760 7418 6361 7179 3657 5497 December 4723 2572 3340 1286 6046 3376 4228 3080 5000 6590 5790 8628 6415 6141 3332 4703
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Average 5778 5765 8395 3359 3323 6014 TT1T 4085 5038 8650 5760 7410 9127 10939 4184 6408 Estimated due to Ice Jem and errenress river discherge date Estimated due to computer down time.
FIGURE 1.
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1987 MNGP PHYSICAL PARAMETERS RIVER FLOW AND FIANT INTAKE 11
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JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC WEEK I
RIVER FLOW
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PLANT INTAKE i
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FIGURE 2.
1987 MNGP PHYSICAL PARAMETERS AkBIENT AND DISCHARGE WATER TEMPERATURE 100-
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FIGURE :3.
MONTHLY AVERAGE RIVER FLOW AT MNGP 26 24'-
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