ML20031C003
| ML20031C003 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 10/01/1981 |
| From: | Bradley E PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Tedesco R Office of Nuclear Reactor Regulation |
| References | |
| P-55-14, NUDOCS 8110060420 | |
| Download: ML20031C003 (10) | |
Text
PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET P.O. BOX 8699 PHILADELPHIA. PA.19101 ED ARD G BA ER.JR' (2152841-4000 eg
,g g,
AND GENERAL COUNSEL EUGENE J. BRADLEY As6OCI ATE GENERAL COUNSEL DON ALD BLANKEN October 1, 1981 RUDCLPH A. CHILLEMI E. C. KIR K H ALL.
T. H. M AMER CORNELL Assis A T GEN R AL COUNSEL EDWARD J CULLEN. JR.
JOHN F. KENNEDY. JR.
ea ASSISTANT COUNSEL f
f L
4_2 O C T 5 E.s g "r. 3 Mr. Robs t L. Tedesco Assistant Director of Licensing ws. n,ctAE arcutArcar /
Division of Licensing
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W '8 m 1 jQ United States Nuclear Regulatory Commission N L'
'Q Washington, DC 20$$$
Re: Limerick Generating Station, Units 1 & 2 Docket Nos.
50-352 and 50-353
Dear Mr. Tedesco:
Your letter of April 20, 1981, requested additional infomation relative to the potential effects of blasting at the Pottstown Traprock Quarry on curing concrete for Class I structures at the Limerick Generating Station. The infomation which you requested is provided in Attachment 1 enclosed herewith.
Very truly yours t
Euge J.
dley RLF/dmj Attachment O
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J 8110060420 811001 oDR ADOCK 05000352 A
A:tcchm3nt No. 1 LIMERIPM GENERATING STATION DOCKET NUMBERS 50-352 AND S0-353 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION ( RAI) REGARDING CORRELATION OF QUARRY BT.ASTING AND CURING CONCRETE RAI "Please nrovide a correlation of quarry blasts with Class I concrete that was in the process of curing out to seven days after pouring.
Identify the structures and locations in the plant of any concrete that was curing during quarry blasting and the distance to the blast.
Include an estimate of the peak velocity at the location of the pour associated with the subject blasts together with a sample of the methodology used to calculate the attenuation through soil."
RESPONSE
The procedure used to develop the peak velocity estimates is out-lined below.
First, all available Pottstown Traprock Quarry blast information was obtained from the time of the first Class I structure concrete pours in mid-1974 until the latest available information to the end of the June, 1981.
A total of 77 quarry blasts were l
found to have occurred during that time interval.
The dates and l
maximum charge sizes per delay for each of these 77 blasts are listed in Table 1.
The information source for this data is the blasting contractor records on file at the Pottstown Traprock Quarry offices.
Next, records of all concrete pours at Class I structures occurring P-55/14 l l
4 RESPONSE (Continued) on or up to seven days before any of the blast dates were collected.
The Class I structures involved in this collected information are the Reactor enclosure, Control structure and the Spray Pond pump structure.
The Reactor enclosure and Control structure are es-sentially at the same location on the site, consequently for the purpose of this report, the two structures are considered as one and identified as Reactor enclosure / Control structure.
There were almost three hundred concrete pours at these Class I structure sites within seven days of a quarry blast.
All but 15 of these pours were at the Reactor enclosure / Control structure, the remaining 15 being at the Spray Pond pump enclosure.
Finally, all quarry blast velocity monitoring data available was collected.
This data set consists of 44 records from 30 separate blasts occuring between June 24, 1968 and December 19, 1980.
The dates, maximum charge sizes per delay, recording distances, and peak velocity component values are listed in Table 2.
The infor-mation source for this data is the blast monitcring contractor records on file either at the Pottstown Traprock Quarry or the Philadelphia Electric Company offices.
Because no Class I structure concrete pours occurred before mid-1974, monitored blasts before this date in Table 2 are not shown in Table 1.
Because not all quarry blasts have been monitored after mid-1974, some blasts in Table 1 do not appear in Table 2.
From the oistance and maximum charge per delay data in Table 2 scaled distances were calculated.
Scaled distance is defined as the P-55/14.. -
RESPONSE (Continued) distance (in feet) divided by the square root of the maximum charge i
(in lbs) per delay.
A log-log plot of peak component velocity as a function of scaled distance for each of the 44 records of Table 2 is shown in Figure 1.
Also shown in this figure is the least squares best fit regression of the log velocity / log scaled distance data.
The equation of the best fit curve is log V (in/sec) = 1.75 - 1.55 log X (ft/lbs/ delay)
The equation was determined using a computer program developed by SAS Institute, Inc., Cary, NC 27511.
This program has received wide usage and acceptance.
Blasts 62 through 71 in Table 1 have all been monitored at the Reactor enclosure / Control structure and blasts 63 through 71 have been monitored at the Spray Pond pump enclosure as well.
Where measurable peak velocities at these locations exist they appear in Table 2, record numbers 28, 30, 33, 34, 36, 39 and 42 for the Spray Pond plump enclosure, and 25, 27, 32, 35, 38, 41 and 44 for the Reactor enclosurc/ Control structure.
These peak velocities have been used in velocity scaled distance regression.
Therefore, the derived equation is directly applicable at these locations.
Using this equation and the maximum charge per delay sizes of Table 1, estimates of peak velocities at Class I structures may be made once distances are known.
For preliminary calculation purposes, the minimum distances between the Pottstown Traprock Quarry and.
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RESPONSE (Continued)
Class I structures were determined.
These are about 1850 feet and 3300 feet for the Spray Pond pump and the Reactor enclosure /
Control Structure, respectively.
This is indicated in figure 2.
I For these distance, utilizing the charges for each blast and the best fit regression curve, estimated peak velocities were calcu-lated far each blast at each Class I structure.
These calculated values ranged from 0.009 to 0.057 in/sec.
The 10 blasts which produced the calculated maximum peak velocities at the Spray Pond Pump structure or the Reactor enclosure / Control structure are listed o:: Table 3.
Reinforced concrete columns will support the spray network piping in the spray pond.
The nearest approach of these columns to the blast point is approximately 1325 feet.
Calculations indicate that a blast with a charge of about 500 lbs/ delay will produce a maximum peak velocity of 0.1 ips at the closest column.
For this reason, if a quarry blast with a charge greater than 500 lbs/ delay is scheduled for the same day as a concrete pour of a column, the pour will be re-scheduled.
We consider these recorded velocities to be within acceptable limits and conclude that quarry blasting does not have a detrimental effect on the curing of concrete.
P-55/14 --
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TABLE 1 POTTSTOWN TRAPROCK QUARRY BLASTS 11 JULY 74 - 30 June 81 Numbe_r Date_
_ l_bs/_delal)
(
max Number Da_te
( I b/d el ay)__ _ma_ x 1
11 Jul 74 488 40 28 Jun 77 479 2
6 Aug 74 627 41 29 Jul 77 329 3
4 Sep 74 682 42 14 Sep 77 356 4
2 Oct 74 602 43 19 Sep 77 409 5
9 Oct 74 708 44 13 Apr 78 524 6
24 Oct 74 543 45 26 May 78 454 7
1 Nov 74 582 46 20 Jun 78 900 8
2 Dec 74 593 47 20 Jun 78 507 9
7 Feb 75 516 48 1 Aug 78 709 10 1 Apr 75 501 49 3 Aug 78 477 11 11 Apr 75 224 50 7 Sep 78 427 12 18 Apr 75 494 51 17 Oct 78 403 13 2 Jun 75 568 52 17 Nov 78 430 14 9 Jul 75 571 53 29 Dec 78 350 15 19 Aug 75 603 54 11 Apr 78 406 16 10 Sep 75 602 55 7 May 79 408 17 6 Oct 75 553 56 5 Jun 79 400
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18 27 Oct 75 541 57 27 Jun 79 400 19 17 Nov 75 642 58 23 Jul 79 450 20 21 Nov 75 140 59 29 Aug 19 455 21 18 Dec 75 642 60 28 Sep 79 455 22 31 Dec 75 643 61 30 Oct 79 343 23 9 Jan 76 542 62 4 Feb 80 410 24 16 Jan 76 353 63 3 Apr 80 435 25 8 Apr 76 668 64 8 May 80 325 26 23 Apr 76 594 65 29 May 80 336 27 27 Apr 76 359 66 24 Jun 80 392 28 14 May 76 557 67 21 Jul 80 373 29 4 Jun 76 542 68 14 Aug 80 359 30 18 Jun 76 590 69 2 Sep 80 357 31 21 Jul 76 612 70 21 Oct 80 405 32 19 Aug 76 593 71 19 Dec 80 288 33 10 Sep 76 572 72 10 Mar 81 216 34 10 Nov 76 541 73 11 Apr 81 357 35 15 Mar 77 531 74 20 Apr 81 320 36 6 Apr 77 583 75 3 Jun 81 309 37 13 May 77 492 76 11 Jun 81 200 38 24 May 77 333 77 30 Jun 81 280 39 17 Jun 77 683
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TABLE 2
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MONITORED PEAK VELOCITIES Number Date (lbs/ delay) max Distance (ft)
Peak vel. (in/sec) 1 24 Jun 68 614 600 1.00 2
24 Jun 70 629 250 1.90 3
24 Jun 70 629 2800
.03 4
8 Oct 71 876 720
.28 5
3 Nov 71 1026 580 1.05 6
12 Jan 72 552 400 2.60 7
27 Jan 72 942 600
.92 8
18 Apr 72 353 550
.49 9
28 Jul 72 453 600 1.58 10 27 Jun 73 390 150
.62 11 20 Jul 73 362 250
.99 12 24 Aug 73 847 300 1.36 13 14 Mar 74 569 600
.85 14 22 Apr 74 601 400
.23 15 26 Jun 74 592 400
.27 16 4 Sep 74 682 500
.67 17 1 Nov 74 406 300
.62 18 8 Apr 76 669 527
.32 19 11 Apr 79 406 300
.61 20 7 May 79 409 600
.34 21 5 Jun 79 400 600
.49
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22 23 Jul 79 450 600
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23 4 Feb 80 410 1850
.09 24 4 Feb 80 410 2820
.03 25 4 Feb 80 410 3900
.02 26 3 Apr 80 435 2930
.02 27 3 Apr 80 435 3940
.01 28 8 May 80 325 2410
.03 29 8 May 80 325 2850
.04 30 29 May 80 336 2430
.02 31 29 May 80 336 2870
.03 32 29 May 80 336 3880
.02 33 24 May 80 372 2445
.02 34 21 Jul 80 373 2445
.012 35 21 Jul 80 373 3895
.01 36 14 Aug 80 359 2465
.02 37 14 Aug 80 359 2930
.02 38 14 Aug 80 359 3915
.02 39 21 Oct 80 405 2490
.02 40 21 Oct 80 405 2955
.03 41 21 Oct 80 405 3940
.02 42 19 Dec 80 288 2505
.02 43 19 09c 80 288 2970
.02 44 19 Dec 80 288 3955
.015
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f TABLE 3 CALCULATED MAXIMUM PEAK VELOCITIES AT CLAGS I STRUCTURES max Distance (ft)
Peak vel. (in/sec)
Date ilbs/ delay) 23 Jul 79 450 1850 0.057 11 Apr 79 406 1850 0.052 21 Oct 80 405 1850 0.052 27 Jun 79 400 1850 0.052 29 Dec 78 350 1850 0.047 8 May 80 325 1850 0.044 19 Dec 80 288 1850 0.040 20 Jun 78 900 3300 0.040 1 Aug 78 709 3300 0.033 9 Oct 74 708 3300 0.033
(
NOTE:
Placement of concrete at the Spray Pond pump enclosure began on December 20, 1978.
Therefore, for those blasts made prior to that date, the estimated peak velocity at the Reactor enclosure / Control structure is shown while for blasts that occurred after December 20, 1978 the estimated peak velocity at the Spray Pond pump enclosure is indicated.
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FIGURE 1
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CLASSI STRUCTUF<E POUR SITES N 6000 REACTOR BUILDING FIGURE 2
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