ML19339B630
| ML19339B630 | |
| Person / Time | |
|---|---|
| Site: | 07106698 |
| Issue date: | 10/02/1980 |
| From: | Clay Johnson NAC INTERNATIONAL INC. (FORMERLY NUCLEAR ASSURANCE |
| To: | Macdonald C NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| Shared Package | |
| ML19339B620 | List: |
| References | |
| 17575, CRJ-80-158-ETS, NUDOCS 8011070350 | |
| Download: ML19339B630 (2) | |
Text
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Os NuTeor Assurance Corporetton 24'Executwo Park West Attanta. Georga 30329 1404) 325-4200 7eiex: 549567. 542703 75 r*cn:on :nve Grana Junc: ton cacracc 9'5C:
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< 01) 47Ce44 Tetex' 57275 October 2,1980 CRJ/80/158/ETS Mr. C. E. MacDonald Chief, Transportation Certification Branch Division of Fuel Cycle and Material Safety U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Mr. MacDonald:
As we discussed this morning, we ran a few cases to check the sensitiv-ity of the chi-square test as we applied it to the NAC-10 cask.
The attached graphs show the results of these tests..
We artificially changed three data points in each of three samples used in applying the chi-square test to the cavity dimensions of the D cask.
The graphs are plots of what happens to the chi-square value as a function of artificially changed diametral differences.
For example, in the first case, we changed three dimensions in the cavity zone between 4.5 and 36.5 inches.
The changes were made at locations 18.5, 24.5 and 30.5 inches, where the original changes from the 1970 to the average of the 1980 values were
.004,
.006 and +.005 inches, respectively.
The original chi-square value for this zone of the cask was 59.65 with boundaries at 36.7 to 60.4.
When we changed the three points by 15, 30 and 45 mils, the chi-square value as well as the chi-square boundaries changed and, as noted on the graph, we exceed the chi-square boundary when we artificially changed the values by 30 mils.
Based on these comparisons, we conclude that the chi-square test is cacable of detecting cavity configuration changes that would be representa-tive of buckling while at the same time the chi-square test is not so sensitive that it lill give us an excessive number of false indications of cavity configuration changes.
We will be happy to discuss this further with you, t
Sincerely, NUCLEAR ASSURANCE CORPORATION
/
f /Y.& 4<N CharleT'k,. Johnson Vice President Engineering & Transportation Services CRJ:cnr 801107036&
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.05 DlAMETRAL CllANCE (lNCHES) 4.5 to 36.5 inches 78.5 to 108.5 inches 114.5 to 144.5 inches Diameter Changes at:
Diameter Changes at:
Diameter Changes at:
18.5 24.5 30.5 90.5 96.5 102.5 120.5 126.5 132.5 Original
.004
.006
+.005 Original
.011
.003
.001 Original
.016
.003
.004 Case 1
.019
.021
.010 Case 1
.026
.018
.026 Case 1
.031
. 0 111
.019 Case 2
.034
.036
.025 Case 2
.041
.033
.041 Case 2
.046
.033
.034 Case 3
.049
.051
.040 Case 3
.056
.048
.056 Case 3
.061
.048
.049