ML19343C159
| ML19343C159 | |
| Person / Time | |
|---|---|
| Site: | 07106346 |
| Issue date: | 01/29/1981 |
| From: | Mcdonald C NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Mowry W GENERAL ATOMICS (FORMERLY GA TECHNOLOGIES, INC./GENER |
| References | |
| NUDOCS 8102180788 | |
| Download: ML19343C159 (2) | |
Text
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UNITED STATES g
NUCLEAR REGULATORY COMMISSION a
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WASHINGTON. D. C. 20655
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JAN 2 91981 7'g.o FCTC: RHO
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71-6346 I[f FE9 0 21981> $
c General Atomic Company
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ATTN: Mr. William R. Mowry P. O. Box 81608 S&n Diego, CA 92138 V->
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"'I W Gentlemen:
This refers to your application dated October 9,1980, requesting an amendment to the Model No. FSV-1 packaging.
In connection with our review, we need the information identified in the enclosure to this letter.
Please advise us within thirty (30) days from the date of this letter when this information will be provided. The additional infomation requested by this letter should be subritted in the fom of revised pages.
If you have any questions regarding this matter, we would be pleased to meet with you and your staff.
Sincerely, M
Charles E. MacDonald, Chief Transportation Certification Branch Division of Fuel Cycle and Material Safety
Enclosure:
As stated O
8102180
y
. General Atomic Comoany
_Model FSV-1, HLW Revision m 2 91981 71-6346 Enc 1 to ltr dtd:
STRUCTURAL
,4 Reference is made to Section 5-0 df GADR-55, Addendum 1. P.evision 1.
It was noted that the H0NDO analysis for the 30 foot bottom drop case, the element at-the vicinity of the junction of the container lid and the container displayed very large tensile stress (i.e., element 468, axial tensile stress = 50,990 psi).
Based on the stress output of the HONDO run of those elements at the vicinity of the container lid closure bolts, compute the resulting stress and the pre-load of the closure bolts and discuss the ability of the containment seal to maintain leak tightness under this condition.
'2 2
CONTAINMENT The ap211 cation concludes that permissible leakage rates of less than 1 x 10-7 atm-cm1/sec for dry air at 250C is indicated using ANSI N14.5 methods. The Parker Co.'s guidance for elastomer material is given as justification for using a test of i x 10-4atm-cm3/sec sensitivity for initial and periodic tests.
The assembly verification test is proposed at a sensitivity of 1 x 10-3atm-cm3/sec.
The same test is proposed for each sencitivity with a longer wait time for the more sensitive test.
The Parker 0-ring guidance states jhat no liquid will pemeate an elastomer seal having air leakage of 1 x 10 atm-cm3/sec or less. However, the basis for the ANSI N14.5 leaktightness definition is NASA CR 106139 whichstates that moisture (water) in the air blocks leakage at about 1 x 10-'atm-cm3/sec when equal or greater sensitivities are indicated by ANSI N14.5.
It is also noted that the intent of allov.ng a-less sensitive test for assembly verification is to avoid more exotic cedures on a routine basis.
It is
_.em will actually perfom within the assumed in this approar+ ' " - ' "
normal -l u
.e,ange at each assembly. The assembly leak test is used to verity. oper assembly with some restriction to the maximum possible release. The proposal to use the same precedure with different hold or obser-vation times seems to violate the intent of this requirement.
The permanently closed parts of the containment system (i.e., welded plugs, etc.) should be leak tested prior to first use and periodically.
Based on the above discussion, please provide the following: the containment structure should be initially anc periopically jannually) leak tested using a test at least as sensitive as 1 x 10- atm-cm /sec unless a less sensitive test can be justified.
(This does not preclude the need for an assembly verification test prior to each shipment.)
.