ML20210L596
| ML20210L596 | |
| Person / Time | |
|---|---|
| Site: | 07103052 |
| Issue date: | 08/03/1999 |
| From: | Brach E NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Boyle R TRANSPORTATION, DEPT. OF |
| References | |
| NUDOCS 9908090176 | |
| Download: ML20210L596 (6) | |
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g *, UNITED STATES g j NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. enana annt
\ . . . . . ,o# August 3, 1999 Mr. Richard W. Boyle Radioactive Materials Branch U.S. Department of Transportation 400 Seventh Street, S.W.
Washington, D.C. 20590
SUBJECT:
MODEL NO. TN-MTR PACKAGE
Dear Mr. Boyle:
This is in response to your letter dated June 18,1999, requesting our assistance in evaluating the Model No. TN-MTR package with a MTR-68 basket, authorized by the French Certificate of Approval No. F/357/B(U)F-85 Aa, dated April 8,1999.
We have performed an acceptance review of the application and have determined that the application is incomplete and that there are some technical 1,ssues that require analysis and resolution. Specifically, the following deficiencies in the safety analysis report were identified:
- 1) The MTR-68 fuel basket design uses different alloy of aluminum as a structural member than was analyzed in the scale model tests. The scale model tests must be consistent with the full scale package design that is described in the application.
- 2) The criticality analysis does not include a benchmarking analysis and does not consider calculation bias. ,
- 3) The aluminum fuel cladding and aluminum structural members reach temperatures that exceed their maximum service temperatures under normal conditions of transport.
- 4) The package design does not include an adequate safety factor for neutron poison in the MTR-68 basket components.
- 5) The package design includes borated aluminum alloy as a structural member which is / .
not allowed by the ASME Boller and Pressure Vessel Code.
th A more detailed discussion of the application package omissions and inconsistencies is !
provided in the enclosure to this letter. Due to the findings we identified during our acceptance ,
review, we are suspending our technical review of the application. We suggest that you ask the applicant to revise the application to address the findings described in this letter. Please also note that a complete technical review could potentially identify additional technical issues that I would require resolution. ,
1 MCIU(; ENTER CDP 9900090176 990003 PDR ADOC K 071 ****
- C PDR
.. .Mr Richard W. Boyla -
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,_ If you have any questions, please contact Mr. David Tiktinsky at (301)-415-8523 or Mr. Ross Chappell at (301)-415-8510.
Sincerely, j original /s/ by E. William Brach, Director Spent Fuel Project Office Office of Nuclear Material Safety and Safeguards
Enclosure:
As Stated I cc: w/ encl, T. Mustin, DOE
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l DISTRIBUTION:
NRC File Center . 71-3052 SFPO r/f NMSS r/f Public JDunn-Lee, IP ANorris (Closes RIA 00002060S, L22935) i File Name/ Location (c:\wpdocs\71-3052.rej.wpd) Secy initials /date OFC: SFPO E SFPO~ E SFPO E SFPO SFPO SFfO NAME: *DTiktinsky *EZiegler *CRChappell *SShankman *MWHodges hbrach DATE: 7/ /99 7/ /99 7/ /99 7/ /99 7/ /99 [///99 OFFICIAL RECORD COPY l *see previous concurrence
. Mr Richard W. Boyle .
If you have any questions, please contact Mr. David Tiktinsky at (301)-415-8523 or Mr. Ross Chappell at (301)-415-8510.
Sincerely, E. William Brach, Director Spent Fuel Project Office Office of Nuclear Material Safety and Safeguards
Enclosure:
As Stated cc: w/ encl, T. Mustin, DOE o
hf1 t DISTRIBUTION:
NRC File Center 71-3052 SFPO r/f NMSS r/f Public ANorris (Closes RfA 00002060S, L22935)
File Name/ Location (c:\wpdocs\71-3052.re).wpd) Secy initials /date OFC: SFPO E SFPO E SFPO E SFPO SFP,0j SFPO NAME: *DTiktinsky *EZiegler *CRChappell *SShankrnan M Eodges I EWBrach DATE: 7/ /99 7/ /99 7/ /99 7/ /99 7/h9 7 / /99 OFFICIAL RECORD COPY
- see previous concurrence t
, 1 Mr. Richard W. Boyle adioactiva Mat: rials Brcnch
.S. Department of Tr nsportation Seventh Street, S.W.
, shington, D.C. 20590
.SU CT: MODEL NO. TN-MTR PACKAGE '
/
Dear M Boyle:
- This is in sponse to your letter dated June 18,1999, requesting our assistance in evaluating the Model . TN-MTR package with a MTR-68 basket, authorized by thefrench Certificate of
. Approval No. F/357/B(U)F-85 Aa, dated April 8,1999.
We have perforged an acceptance review of the application and t) ave determined that there are substantial incontistencies and omissions in the safety _analysisjeport. Specific inconsistencies and omissions are scribed in the enclosure to thisfletter. I general, the following were identified: /
- 1) The MTR el basket design uses a n ' ndard material as a structural member needed for critica s nt with the physical tests that are described in the a%y control. This is riot pplication.
- 2) The aluminurn fue adding and al um structural members reach temperatures that exceed their maxin$um t servicegemperatures under normal conditions of transport.
- 3) The criticality analysisdoes ot include \ a benchmarking analysis, and
- 4) The package design d not include an adequate safety factor for neutron poison in the MTR-68 basket com nents
. Due to the inconsistenciesynd omissions e identified during our acceptance review, we can not initiate a technical revhw of the applicalion. Please note that a complete technical review
' could potentially ident' additional technical iissues that would require resolution.
If you have any q stions, please contact t me a\(_301) 415-8523.
Sincerely, E. William Brach, Director Spent Fuel Project Office Office of Nuclear Mater}al Safety and Safeguards \
Enclosure:
As Stated cc: w/ encl, T. Mustin, DOE DISTRIBUTION.
NRC File Center 71-3052' SFPO r/f NMSS r/f SShankman EWBrach WHodges. ANorris (Closes RfA 00002060S, L22935)
. File Name/ Location (c:\wpdocs\71-3052.reJ.wpd) Secy initials /date OFC: SFP,0 E SFPO- E Sp E hO SFPO NAME: M nsky EZieglerk (Rdhappell hhankman EWBrach DATE: 7A)99 7f099 #7/ h' OFFEIAL RECORD COPY 7@9 7/ /99 / /99 L
C-71-3052
- - Encl. to ltr. dated August 3,1999 STRUCTURAL EVALUATION AND MATERIALS
- 1) The scale model tests that were performed on the package design used a different alloy of aluminum (not borated) than is proposed to be used in actual packages. In addition, the scale model tests of the package design were not performed at the elevated temperatures that the full scale package would experience under normal :
conditions of transport with a heat load or under hypothetical accident conditions. l
- The yield strength and ultimate strength of aluminum alloys decrease significantly at elevated temperatures. The applicant should provide an evaluation that j demonstrates that the package has adequate structural integrity at the j temperatures that it is expected to experience. j
- 2) ' The MTR-68 basket used in the package consists of 19 discs held together with tie rods. Nine of the discs are constructed of borated aluminum alloy. The ASME Boiler and Pressure Vessel (BPV) code, Section lil, does not allow the use of borated aluminum alloy as a structural material. The applicant analyzed the system of discs, assuming that the borated aluminum discs only needed to support their own weight during the hypothetical accident conditions (HAC) 30-foot drop and 40-inch puncture tests. The application did not consider that fuel assemblies would also transfer a portion of their weight as a mechanical load to the borated aluminum discs during the HAC tests. The structuralintegrity of the borated aluminum alloy discs is required for criticality control of the package. The applicant should revise the application to include use of materials that meet the BPV code or provide additional information qualifying the materials using a recognized code or standard.
- 3) The applicant calculated that the maximum temperature of the MTR-68 basket as 289*C during normal conditions of transport. This temperature is above the maximum service temperature of any aluminum alloy listed in the BPV code, Section lli (400*F or 204*C). In addition, since borated aluminum alloy is not listed in the BPV, the applicant should reference a code or standard for the performance of the selected aluminum alloy at elevated temperatures. The application should also consider the brittle fracture properties of the material at low and elevated temperatures. The application should be revised to denanstrate that the temperature of materials used in the package design is below their maximum service limits.
- 4) The maximum temperature of the aluminum fuel cladding exceeds 204*C, the maximum service temperature of aluminum alloys, by a conr,iderable amount (353*C). Since the cladding is relied upon for bel oeom. dry (i.e. criticality safety) and containment of radioactive material under normal and accident conditions, the application should show that the maximum temperature of the cladding should not exceed 204*C under normal conditions of transport.
Additional information regarding the structural design and material selection can be found in the following reference documents a) Regulatory Guide 7.g, " Standard Format and Content of Part 71 Applications for Approval of Packaging for Radioactive Materials," b) Regulatory Guide 7.8,
" Load Combinations for the Structural Analysis of Shipping Casks for Radioactive Materials,"
c) NUREG/CR-3854, " Fabrication Criteria for Shipping Containers," and d) NUREG 1617,
- " Standard Review Plan for Transportation Packages for Spent Nuclear Fuel."
p CRITICALITY
- 1) The applicant calculated the k-eff for the bounding fuel type in MTR-68 basket to be 0.948. However, the applicant did not include a benchmarking analysis in the application and did not add in a bias value into the calculation of k-eff. The applicant needs to provide an application that includes this information.
- 2) The applicant needs to provide an application that limits the credit for the neutron absorbing boron to 75% instead of the 90% credit used in the application.
I Additional information regarding the criticality evaluations can be found in NUREG/CR-5661,
" Recommendations for Preparing the Criticality Safety Evaluation of Transportation Packages" and NUREG 1617, " Standard Review Plan for Transportation Packages for Spent Nuclear Fuel."
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