ML12319A474
| ML12319A474 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 11/13/2012 |
| From: | John Stanley Constellation Energy Group, Constellation Energy Group, Calvert Cliffs, EDF Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML12319A474 (8) | |
Text
Calvert Cliffs Nuclear Power Plant 1650 Calvert Cliffs Parkway Lusby, Maryland 20657 CENG.
a joint venture of Constellatio°n eOF CALVERT CLIFFS NUCLEAR POWER PLANT November 13, 2012 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION: Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit No. 1; Docket No. 50-317 Submittal of Long Term Coupon Surveillance Results
REFERENCE:
(a) Letter from Mr. D. V. Pickett (NRC) to Mr. J. A. Spina (CCNPP), dated August 27, 2008, Amendment re: Long Term Coupon Surveillance Program As described in Reference (a), attached are the surveillance results from the long term coupon surveillance program for the Unit 1 spent fuel pool storage racks. The attachment contains the most recent surveillance results and the historical surveillance results. The surveillance results meet the acceptance criteria as described in the attachment.
Should you have questions regarding this matter, please contact Mr. Douglas E. Lauver at (410) 495-5219.
JJS/PSF/bjd
Attachment:
(1) Surveillance Results for Long Term Coupon Surveillance Program cc: N. S. Morgan, NRC Resident Inspector, NRC W. M. Dean, NRC S. Gray, DNR
ATTACHMENT (1)
SURVEILLANCE RESULTS FOR LONG TERM COUPON SURVEILLANCE PROGRAM Calvert Cliffs Nuclear Power Plant, LLC November 13, 2012
ATTACHMENT (1)
SURVEILLANCE RESULTS FOR LONG TERM COUPON SURVEILLANCE PROGRAM
SUMMARY
As requested, below are the results of the surveillances of the carborundum coupons contained in the Unit 1 spent fuel pool storage racks. The surveillances have been performed in accordance with the carborundum coupon surveillance program. The latest surveillance was performed as approved by the Nuclear Regulatory Commission in Reference 1. For each coupon removed, the following measurements were performed: visual examination, dimensional measurement, weight, and areal density (2009 only).
Results are within acceptance criteria as shown below.
Figure 1 shows the historical and projected coupon weight loss over the projected life of the spent fuel pool storage racks. The data points on Figure 1 represent the average weight loss of the Accelerated Surveillance Assembly (ASA) coupons removed in a given year. Long Term Surveillance Assembly (LTSA) coupon data is not included on Figure 1 because these coupons have a lower gamma dose than the ASA coupons.
The most recent data obtained continues to show that the weight loss is trending as expected. Our experience is that weight loss is the best predictor of degradation of the borated sheets contained in the spent fuel pool storage racks.
Figure 1 - Historical and Projected Coupon Weight Loss 40 35 .......... .%Change-ASA.
Linear (% Change -
30 ASA) . ....
M-25F r-20 .. . -- --. .
=15 10 .----- -. . .....-....-
0 o00 to Go 0
M~
to M
0 to o UI 0Q
- 0 W) 0 0 Q 0 N N M~ c le l M) 0M 0M 0) 0 0 0 0 0 0 0 0 0 0 N S c DAt N o N N N (-
Service Date (+/m 6 mo)
I
ATTACHMENT (1)
SURVEILLANCE RESULTS FOR LONG TERM COUPON SURVEILLANCE PROGRAM Table 1 provides the weight information for each coupon removed for examination. Our experience with these coupons shows that the primary loss of material in the samples is due to erosion at the inspection holes and to handling losses.
Table I - Results of Weight Measurements Average Init Difference Difference Acceptance Coupon Coupon We t (gm(%) Criteria Date (gm) 1985 1 - lU 11.106 9.294 -1.812 -19.50 +/-26%
1 - IL 10.855 9.079 -1.776 -19.57 +/- 26%
1 -2U 10.850 9.211 -1.639 -17.79 +/-26%
1 -2L 11.003 9.229 -1.774 -19.22 +/-26%
1987 2 - 1U 8.969 9.201 0.232 2.52 +/- 26%
2 - IL 8.94 9.098 0.158 1.74 +/-26%
2 -2U 8.728 8.98 0.252 2.81 +/-26%
2-2L 8.769 8.941 0.172 1.92 +/-26%
1987 LTSA 25 - IU 8.72 8.895 0.175 1.97 +/- 26%
25 -IL 8.884 9.013 0.129 1.43 +/-26%
25 - 2U 8.823 8.996 0.173 1.92 +/-26%
25 - 2L 8.83 8.953 0.123 1.37 +/-26%
1989 7 - 1U 8.515 8.802 0.287 3.26 +/- 26%
7- IL 8.753 8.968 0.215 2.40 +/- 26%
7-2U 8.893 9.31 0.417 4.48 +/- 26%
7 - 2L 9.098 9.222 0.124 1.34 +/-26%
1991 8-lU 7.415 9.08 1.665 18.34 +/-26%
8 - 1L 8.607 8.952 0.345 3.85 +/- 26%
8-2U 8.4 8.856 0.456 5.15 +/-26%
8 - 2L 8.664 8.908 0.244 2.74 +/- 26%
1991 LTSA 26 - 1U 8.799 9.09 0.291 3.20 +/- 26%
26- 1L 8.482 8.933 0.451 5.05 +/-26%
26-2U 8.597 8.817 0.22 2.50 +/-26%
26 - 2L 8.706 8.885 0.179 2.01 +/-26%
1993 9- lU 8.487 9.017 0.53 5.88 +/-26%
9- IL 8.842 9.09 0.248 2.73 +/--26%
9 - 2U 8.979 9.31 0.331 3.56 +/-26%
9 - 2L 8.487 8.929 0.442 4.95 +/- 26%
1995 10 - IU 9.299 8.99 -0.309 -3.44 +/-26%
10- IL 9.471 8.882 -0.589 -6.63 +/- 26%
10 -2U 9.486 9.155 -0.331 -3.62 +/-26%
10 - 2L 9.163 9.068 -0.095 -1.05 +/-26%
1995 LTSA 31 - lU 9.496 9.014 -0.482 -5.35 +/-26%
31 - IL 9.248 8.636 -0.612 -7.09 +/- 26%
31 -2U 9.317 8.836 -0.481 -5.44 +/-26%
31 -2L 9.643 8.891 -0.752 -8.46 +/-26%
1997 15 - lU 8.753 9.308 0.555 5.96 +/-26%
15 - IL 8.494 8.833 0.339 3.84 +/- 26%
15 - 2U 8.297 8.733 0.436 4.99 +/-26%
15 - 2L 8.284 9.004 0.72 8.00 +/- 26% -
2
ATTACHMENT (1)
SURVEILLANCE RESULTS FOR LONG TERM COUPON SURVEILLANCE PROGRAM Scheduled Average Initial Difference Difference Acceptance Coupon Coupon Weight (gm) Weight (gm) (%) Criteria Date (gm) 2000 LTSA 32 - 1U 8.844 9.309 0.465 5.00 +/- 26%
32 - IL 9.084 9.355 0.271 2.90 +/- 26%
32 - 2U 8.118 8.568 0.45 5.25 +/-26%
32 - 2L 8.521 8.806 0.285 3.24 +/-26%
2005 16 - 1U 7.8864 9.046 1,1596 12.82 +/-26%
16- IL 8.2735 8.93 0.6565 7.35 +/- 26%
16 - 2U 7.9944 8.975 0.9806 10.93 +/-26%
16 - 2L 8.3797 9.01 0.6303 7.00 +/-26%
2009 17 - lU 7.901 9.221 1.320 14.3 +/-26%
17 - IL 8.330 9.077 0.747 8.2 +/- 26%
17 - 2U 7.735 8.961 1.226 13.2 +/- 26%
1772L 8.089 9.300 1.211 13.0 +/-26%
Table 2 provides the detailed results for the length and width dimensional measurements for each coupon removed for inspection. Many of the small changes in dimension that are observed are due to curvature of the thin coupons during the drying process.
Table 2 - Results of Dimensional Measurements Scheduled Average Initial Difference Average Initial Difference Acceptance Coupon Coupon Length Length (in) Width Width (in) Criteria Date (in) (in) (in) (in) (in) 1985 1 - lU 4.016 4.019 0.003 2.014 2.018 0.004 +/-0.5 1 - IL 4.016 4.023 0.007 1.997 1.999 0.002 +/- 0.5 1 -22U 4.007 4.016 0.009 1.996 2.003 0.007 +/-0.5 1 -2L 3.999 4.005 0.006 2.012 2.016 0.004 +/-0.5 1987 2- lU 4.003 4.01 0.007 1.997 2.006 0.009 +/-0.5 2- IL 4.003 4.009 0,006 1.983 1.985 0.002 +/-0.5 2-2U 4.003 3.993 -0.009 1.885 1.993 0.108 +/-0.5 2-2L 3.991 4.004 0.013 2.001 2.010 0.009 +1-0.5 1987 25 - 1U 3.989 3.994 0.005 1.987 1.992 0.004 +1- 0.5 LTSA 25 - IL 3.994 4.002 0.008 2.020 2.022 0.002 +/- 0.5 25-2U 4.009 4.014 0.005 1.981 1.984 0.003 +/-0.5 25 -2L 4.007 4,011 0.004 2.014 2.018 0,004 +1- 0,5 1989 7 - 1U 3.998 3.997 -0.001 1.989 1.993 0.004 +/- 0.5 7- IL 3.980 3.987 0.007 2.001 2.013 0.012 +/- 0.5 7-2U 4.026 4.033 0.007 1.977 2.013 0.036 +/-0.5 7-2L 4.002 4.012 0.010 1.982 1.999 0.017 +/-0.5 1991 8 - 1U 4.020 4.036 0.015 2.015 2.020 0.005 +/- 0.5 8-1L 3.977 3.983 0.006 1.977 2.011 0.034 +/-0.5 8 - 2U 3.993 4.012 0.019 2.004 2.006 0.002 +1- 0.5 8 - 2L 3.975 4.004 0.029 2.007 1.985 -0.022 +1- 0.5 3
ATTACHMENT (1)
SURVEILLANCE RESULTS FOR LONG TERM COUPON SURVEILLANCE PROGRAM Scheduled Average Initial Difference Average Initial Difference Acceptance Coupon Coupon Length Length (in) Width Width (in)_Criteria Date (in) (in) (in)__in__(in) (in) (in) 1991 26- lU 3.967 3.979 0.013 2.031 2.041 0.010 +1-0.5 LTSA _ 1_
26- IL 3.993 4.002 0.009 1.988 1.998 0.010 +1-0.5 26-2U 3.991 4.003 0.012 2.011 2.013 0.002 +/-0.5 26- 2L 4.031 4.035 0.004 1.999 2.005 0.006 +/-0.5 1993 9-lU 4.002 4.000 -0.003 2.010 1.997 0.013 +/-0.5 9-iL 4.018 4.013 -0.004 2.029 2.030 -0.001 +/-0.5 9-2U 4.000 4.011 0.011 2.023 2.003 0.021 +1-0.5 9-2L 3.976 3.990 0.014 1.997 1.982 0.016 +/-0.5 1995 10- 1U 4.032 4.041 0.009 1.981 1.988 0.007 +/- 0.5 10- IL 4.043 4.059 0.017 1.992 2.002 0.010 +1-0.5 10- 2U 3.997 4.009 0.012 1.971 1.991 0.020 +/-0.5 10- 2L 3.969 3.989 0.021 1.968 1.980 0.013 +1-0.5 1995 31 - 1U 3.986 4.001 0.015 2.022 2.029 0.007 +/- 0.5 LTSA 31 - IL 3.957 3.968 0.011 1.987 1.993 0.006 +1-0.5 31 -2U 3.985 4.003 0.017 2.012 2.019 0.007 +/-0.5 31 - 2L 4.000 4.007 0.007 1.998 2.005 0.007 +1- 0.5 1997 15 - 1U 4.009 4.019 0.009 2.001 2.008 0.007 +1- 0.5 15 - IL 3.997 4.005 0.009 2.000 2.006 0.006 +/- 0.5 15-2U 3.980 3.981 0.001 1.959 1.994 0.036 +/-0.5 15 - 2L 3.993 4.004 0.011 1.961 1.999 0.038 +/-0.5 2000 32- lU 3.993 4.006 0.013 1.983 1.996 0.013 +1-0.5 LTSA 32- IL 3.998 4.004 0.006 2.013 2.024 0.011 +/- 0.5 32-2U 4.026 4.035 0.010 1.981 2.000 0.018 +/-0.5 32-2L 4.020 4.027 0.007 1.978 1.999 0.021 +/-0.5 2005 16- lU 4.010 4.023 0.013 1.999 2.014 0.015 +/-0.5 16- IL 3.983 3.992 0.010 1.940 1.979 0.039 +1-0.5 16- 2U 3.968 3.987 0.019 1.974 1.999 0.025 +/-0.5 16-2L 3.992 4.002 0.009 1.981 2.012 0.031 +/-0.5 2009 17 - lU 3.990 3.991 0.001 1.997 2.014 0.017 +1-0.5 17 - IL 3.727 3.994 0.267 1.900 2.010 0.110 +/-0.5 17 - 2U 3.857 4.013 0.156 1.950 1.987 0.037 +/- 0.5 17 - 2L 3.978 4.000 0.022 1.990 1.969 -0.021 +1- 0.5 Areal density measurements were performed on the coupon removed from the spent fuel pool storage racks in 2009. The areal density measurement was performed at Pennsylvania State University in 2010.
Results of this measurement are shown on Table 3. The measurement was taken on a single thickness of carborundum sheet. The spent fuel pool storage racks are constructed with double thickness carborundum sheets. The areal density value has been adjusted for this double thickness.
.4
ATTACHMENT (1)
SURVEILLANCE RESULTS FOR LONG TERM COUPON SURVEILLANCE PROGRAM Table 3 - Results of Areal Density Measurements Scheduled Areal Density Value Acceptance Criteria Coupon Coupon (gm/Cm 2) (gm/cm 2)
Date _ gm'cm__
2009 17- lU 0.028 > 0.0177 17 - IL 0.028 > 0.0177 17 - 2U 0.028 > 0.0177 17 - 2L 0.028 > 0.0177 Table 4 contains the visual inspection results. The grading scale used for Table 4 is given at the end of the table.
Table 4 - Results of Visual Inspection Scheduled Visual Scheduled Visual Coupon Coupon Inspection Coupon Coupon Inspection Date Date 1985 1-lU 3 1995 10- lU 3 1-i1L 3 10-IL I 1 -2U 3 10 - 2U 3 1 -2L 3 10 - 2L I 1987 2- lU 3 1995 LTSA 31 - 1U 3 2-IL 3 31 - IL I 2-2U 3 31 -2U 3 2-2L 3 31 -2L 1 1987 LTSA 25- lU 3 1997 15_- 1U 3 25- IL 3 15_- IL 3 25 - 2U 3 15 - 2U 3 25 -2L 3 15 - 2L 3 1989 7- 1U 5 2005 16- 1U 3 7-IL 4 16- IL 3 7-2U 5 16 - 2U 3 7-2L 4 16 - 2L 3 1991 8- lU 5 2009 17- 1U 3 8- IL 3 17- IL 3 8-2U 5 17 -2U 3 8 - 2L 3 17 - 2L 3 1991 LTSA 26- lU 3 26- IL 3 26-2U 2 26-2L 3 1993 9- 1U 5 9-IL 3 9-2U 5 9-2L 3 5
ATTACHMENT (1)
SURVEILLANCE RESULTS FOR LONG TERM COUPON SURVEILLANCE PROGRAM Visual Inspection Criteria Category Description I B4C grains intact and surface texture uniform on both sides; no visible discoloration as compared to archive samples.
2 B4C grains intact and surface texture uniform on both sides; visible discoloration as compared to archive samples.
3 Minor loss of B 4C grains at surface, either side, but no appreciable missing material 4 B 4C grains intact and surface texture uniform on both sides, however, cracks, blisters or separation of fiberglass backing and binder 5 B 4C grains at surface, either side, noticeably loose and falling off leaving significant craters.
6 Conditions more severe than above.
References
- 1. Letter from Mr. D. V. Pickett (NRC) to Mr. J. A. Spina (CCNPP), dated August 27, 2008, Amendment re: Long Term Coupon Surveillance Program 6