ML19330B999
| ML19330B999 | |
| Person / Time | |
|---|---|
| Site: | 07109116 |
| Issue date: | 02/04/1980 |
| From: | Macdonald C NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Hansen L NUCLEAR PACKAGING, INC. |
| References | |
| NUDOCS 8008070397 | |
| Download: ML19330B999 (2) | |
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NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555
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- FEB 0 4 ISoD W-9u(q Nuclear Packaging, Inc.
ATTN: Mr. L. J. Hansen 815 South 28th Street Tacoma, WA 98409
Dear Mr. Hansen:
This is in regard to your letter of November 1,1979, concerning evaluation of package des.igns under cold temperature conditions.
You are correct in your observation that 10 CFR Part 71 does not require the -40*F condition to be evaluated in conjunction with other tests. Also,10 CFR Part 71 does not specify the ambient temperature conditions that should be co'nsicered when-evaluating the various normal and accident condition tests such as the Free-Drop Tests. We note the IAEA Regulations (Safety Series No. 6) specify in Paragraph 213, that brittle fracture should be considered in the des.ign of the packaging to temperatur,es as low as -40*F (-40*C).
.For some designs, temperature can strongly irifluence the test results and performance of a package.
For example, with cold temperatures:
liquids in the packaoe may be frozen, stresses may be induced by differential thermal contraction, material properties such as the crush strength of impact "
limiters may be changed, and materials of construction may be susceptible to brittle failur'e. Therefore, we believe it is important to evaluate packages under the normal.and accident condition tests at cold ambient temperatures.
Currently,10 CFR Part 71 does not specify a temperature for this purpose.
However, Regulatory Guide 7.8, " Load Combinations for the Structural Analysis j
of Shipping Casks," specifies load conditions that are acceptable to the NRC'
,l staff for evaluating the structural adequacy of shf pping casks.
In that document, an initial temoerature of -20*F is prescribed as the lower limit for which casks must be evaluated in conjunction with the normal and accident condition tests.
Packa;es must also be evaluated for -40*F, but not in conjunction with other normal or accident test conditions.
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Nuclear Packaging, Inc.
-2 FEB 0 41980
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We are currently in the process of revising 10 CFR Part 71. Proposed changes
.... Ti to 10 CFR Part 71 were recently published for pch)ic coment.
In the proposed regulations,.the Normal Conditions of Transport include a separate test at
-40*F. - The other 0.ests included under both Normal Conditions of Transport.and liypo.thetical~ Accident Conditions are required to be considered in conjunction with temperatures as low as -20'F.
Until a final Rule is adopted, we believe a
padages should be evaluated at cold temperatures consistent with the Regulatory Position described in Regulatory Guide 7.8.
We recognize that cold temperature is an important consideration in selecting' materials with suitable toughness. We agree with your suggestion that
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acceptance criteria for evaluating materials is needed. The NRC Office of
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Standards Deselopment is developing a Regulatory Guide on this subject with Y. -
assistance from Oak Ridge National Laboratory. Until that effort is completed,
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the adequacy of materials from the standpoint of brittle failure must continue to be demonstrated to be adequate by the applicant and evaluated by the Branch
.,7 on a case-by-case basis.
I hope triis letter is responsive to your concerns.
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Sincerely,
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Charles E. MacDonald, Chie~f i
Transportation Certification Branch \\
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Division of Fuel Cycle
"""d" and Material Safety
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