ML20215A270
| ML20215A270 | |
| Person / Time | |
|---|---|
| Site: | 07109792 |
| Issue date: | 06/03/1987 |
| From: | Macdonald C NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Engel W ENERGY, DEPT. OF |
| References | |
| NUDOCS 8706160590 | |
| Download: ML20215A270 (2) | |
Text
, blurn'ho OCS .3 ff-ST Eeron bwir SGTB: RHO 71-9792 M 3M Department of Energy ATTN: Mr. W. P. Engel Division of Naval Reactors Washington, DC 20585 Gentlemen:
This refers to your letter dated March 27, 1987, which was a partial response to our letter dated December 29, 1986, concerning the Model No. DIG Core Basket-Thermal Shield Model 1 package.
In connection with our review, we need the information identified in the enclosure to this letter.
j Please advise us within 30 days from the date of this letter when this information will be provided. Additional information requested by this letter should be submitted in the form of revised pages. If you have any questions regarding this matter, we would be pleased to meet with you and your staff.
, Sincerely, Original Signed by CHARLES X. MACDOMUD Charles E. MacDonald, Chief Transportation Branch Division of Safeguards and Transportation, NMSS
Enclosure:
As stated Distribution: w/ encl Docket File 'NRC'POR3
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- SGT NAME:RH0degaarden:HWLee :EPEaston :C rotta:WH(5ke :CRChappell:CEM bnald DATE:06/0/87 :06/03/87:06/ /87 :06/c3/87 :06/o1/87:06/3 /87 :06/1/87 0FFICIAL RECORD CDP.Y 8706160590 870603 7 PDR ADOCK 071 py2 C
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- f ucuq'o 'g UNITED STATES 8" o NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555
$9. . . . . ,o Department of Energy '
Division of Naval Reactors Model No. DIG Core Basket-Thermal Shield Model 1 Package Docket No. 71-9792
. Encl to ltr dtd: JUN 3W
- 1. The application does not show that meeting the 2, 5 and 10 g tie-down requirements in 10 CFR 9 71.45(b) is adequate justification for not meet-ing the free-drop test specified in 10 CFR 96 71.51(a)(1) and 71.71(c)(7)
. as a nomal condition of transport. The application should be revised to
! show that the package meets the 1-foot drop test in the orientation that the cask is normally transported.
- 2. We do not agree that ultimate stress is an appropriate design limit for the closure head bolts. Also, we can not conclude based on the infoma-tion in the SAR (Appendix 2.10) that the closure bolts can absorb the kinetic energy of the closure plates and contents without failing under 30-foot drop test conditions. The application should be revised to show that the stress intensity in the closure bolts (considering the combined tensile, bending and shear stresses) does not exceed static yield under nomal or accident test conditions.
In order to meet the criteria for preventing brittle fracture of the 3.
cask, the application should show:
- a. Cask is made from material meeting the fracture arrest criterion specified in NRC Draft Regulator Greater Than Four Inches (0.1;"m)y or Guide Entitled " Fracture Toughness ,
- b. Perform rigorous stress analyses of the 30-foot drop and puncture tests and thoroughly inspect the cask to determine the critical tensile stresses and the maximum size of cracks or flaws. Based on the principles of fracture mechanics, show that brittle failure of the cask is precluded for the given flaw size and tensile stresses.
Other factors which should be considered in the evaluation are (1) the lowest service temperature, (2) stress concentrations, (3) residual stresses, and (4) the fracture properties of the cask steel and weldments; or
- c. By means of an appropriate operation control, assure that the lowest service temperature to which the cask will be subjected in transport J is sufficiently high to preclude brittle fracture. Adequate detail i and justification of the operation control should be provided. l l
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