ML20217N266
| ML20217N266 | |
| Person / Time | |
|---|---|
| Site: | 07106553 |
| Issue date: | 10/06/1999 |
| From: | Reynolds R External (Affiliation Not Assigned) |
| To: | Boyle R, Osgood N, Wangler M ENERGY, DEPT. OF, NRC, TRANSPORTATION, DEPT. OF |
| Shared Package | |
| ML20217N272 | List: |
| References | |
| NUDOCS 9910280162 | |
| Download: ML20217N266 (6) | |
Text
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r a BECHTEL JACOBS<kA DOE Contract No. DE-AC05-980R22700 Job No. 23900 e m = c m ac,
October 6,1999 Ms. Nancy L. Osgood.
U. S. Nuclear Regulatory Commission Mail Stop 0-6F18 Washington, DC 20555-0001 Mr. Richard Boyle U. S. Department of Transportation OliMT-DHM-23 400 7th Street Sw Washington, DC 20590 Mr. Mike E. Wangler
' ES-33.2 G-il7 U. S. Departinent of Energy Germantown, MD 20545
Subject:
Request for Changes to ANSI N14.1 Regarding Assay Limits on 10-Ton 48X Cylinders
Dear Colleagues:
A request has been received from Mr. Howard Pulley, of the United States Enrichment Corporation (USEC) for revision of ANSI N14.1 to change the allowable "U assay limit for the 48X UF6 cylinder 2
from 4.5 wt percent to 5.0 wt percent. This would be a significant change for the standard. Although ANSI Standards are consensus based and do not necessarily need unanimous approval for changes, a fundamental change such as this needs full agreement by the regulatory bodies that will be involved with the resulting implementation of the change.
I am requesting that the appropriate individuals in your office review the request and enclosures to determine if this change could be supported. USEC has agreed to provide any additional information required and to meet with the committee, if necessary, to explain the bases for this prop
,d change to the standard. If this preliminary review by your office finds the change to have enough merit to continue f
evaluation, the proposed change will be presented to the entire committee for review and consid ration.
USEC has requested full approval and implementation of this change by September 2000.
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.no 9910280162 990006 PDR ADOCK 07106553 C
PDR 761 Veterans Avenue Kevil Kentucky *42053
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Ms. Osgood, Mr. Boyle, Mr. Wangler i
Page 2 October 6,1999 Since the approval process involves several months after N14.1 approval, the proposed change would need to be presented to the committee at large early in calendar year 2000 in order to support the requested timing. Please respond with a schedule your office could support to complete a preliminary review to determine if the proposed change has merit enough to submit to the committee at large. Please submit the schedule you could support by October 18,1999.
If you have any questions please call me at 270-441-5137.
m *re y w.
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andy 1. Reymolds ANSI N14.1 Chairman RIR:lf LTR-PAD /ETS-LF-99-0040
Enclosure:
L etter, lioward Pulley, USEC, September 27,1999, with enclosures c: w/o encl:
J. W. Arendt, ANSI N14 Chairman P. Crawford, ANSI N14 Secretary M. Darrough, USEC-liq J. C. Massey II. Pulley, USEC-PAD R. E. Scott D. J. Warriner, USEC-PAD File-EMEF-DMC-PAD-RC i
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v r CSEC A Global Energy C.umpany September 27,1999 Mr. Randy Reynolds ANSI N14.1 Subcommittee Chairman Bechtel Jacobs Company LLC 761 Veterans Avenue Kevil, Kentucky 42053
Dear Mr. Reynolds:
Request for Changes to ANSI N14.1 Recardinn Assay Limits on 10-Ton 48X Cylinders The United States Enrichment Corporation (USEC) requests that the ANSI N14.1 Committee revise or supplement the assay limits in ANSI N14.1 for 10-ton 48X cylinders.
These cylinders are typically utilized by the Paducah Gaseous Diffusion Plant (PGDP) for shipping enriched UF (up to 2.75 wt percent) to the Portsmouth Gaseous Diffusion Plant
(
6 235 (PORTS). USEC is undertaking a project to increase the U enrichment at PGDP from the current NRC-authorized assay limit of 2.75 wt percent to 5.5 wt percent. The current plans are to continue shipping PGDP product, at higher assay, to PORTS, for the filling of customer orders. This change is needed to enhance USEC's flexibility and reliability in meeting customer demands.
To support this change, it will be necessary to ship UF product from PGDP to 6
235 PORTS in 10-ton 48X cylinders at assays up to 5.0 wt percent U. Emptied 48X cylinders would be returned to PGDP to be refilled. The cylinders will continue to be shipped between the USEC sites in the Paducah Tiger Overpack. The controls to be in place at the PGDP site will ensure high UF purity (equal to or greater than 99.5 wt percent), with an average 235U 6
enrichment of 5.0 wt percent or less.
I This change would require modifying ANSI N14.1, to reflect an assay limit of up to 235 235 5.0 wt percent U, instead of the current limit of 4.5 wt percent U, for 10-ton 48X cylinders. A detailed summary of the requested changes to ANSI N14.1, and related supporting justification, is provided in Attachment A. Nuclear Criticality Safety Analyses have been performed that support the increased enrichment limit for 10-ton UF cylinders. A 6
copy of these analyses is also enclosed. The analyses show that 10-ton cylinders filled with UF enriched to a "U cnrichment of 5.0 wt percent or less, are significantly suberitical both 2
6 individually and in large arrays, for the conditions specified in 10CFR71., on which package approval is based.
The changes should apply to cylinders currently in use which were fabricated to the 1990 or 1995 version of ANSI N14.1 and to cylinders designed, procured, and fabricated to other sersions of ANSI N14.1.
P(), liox 1410 Paduc ah. KY 42001
~lilephonc 50.' 441-5803 l'ax 50M41-5Hol laip:Hv.n uscuoni Offkes in thermore. CA l'aduc ah, KY Portstnouih. Oi l Wadungton. I X.
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9 L.
y Should you have any questions'or desire a meeting to discuss the proposed change.
USEC would.be glad to arrange and sponsor such a meeting. Please contact Doyle Warriner (270-441-6050), our representative on the ANSI N14.1 committee, with any questions or to -
make arrangements for a meeting. Approval by the committee is requested by September, 2000. The ANSI committee's technical approval and corresponding revision to ANSI N14.1
. would be helpful in obtaining NRC approval of the corresponding changes to USEC's certificate and would assure continued compliance with DOT regulations which require adherence to ANSI N14.1.
Sincerelv 1 Pul y, 'ene 1 anager ducah Gaseous Di ion Plant lip:RLE Attachment Enclosures (2) cc:
'w/o Enclosures K. Ahern M. Buckner M. Darrough, HQ' T. Davis J. Fletcher T. Fletcher T. Hines L. Jackson C. Jones J. Lewis P. Miner, PORTS S. Penrod V. Risner j
M. Robles, llQ I
M. Rogers B. Tilden S. Toelle,1lQ D. Warriner File: 99-890-066
l KITACHMENT A PROPOSED CilANGES TO ANSI N14.1 AND RELATED JUSTIFICATION PROPOSED CHANGES TO ANSI N 14.1:
1)
Section 2 - References. It is suggested that USEC 651, Revision 7 be removed from the list of references. It has recently been revised and is considered a descriptive document rather than a reference standard.
2)
Section 5.5 - lable 1. Change the Maximum Enrichment (wt% 2"U) from 4.5 to 5.
3)
Section 8.1.2 - Make a separate line item for Cylinder Model No. 48X and change the Maximum Enrichment (wt% 2"U) from 4.5 to 5.
4)
Appendix C, Table C1 - Make a separate line item for Cylinder Model No. 48X and change the Maximum Enrichment (wt% 2"U) from 4.5 to 5. (Note: these appendices are identified as not being part of ANSI N14.1, but are included for information only.)
5)
Appendix C - cylinder activity - With the increase in assay, the cylinder activity will also increase proportionately. We will calculate the activity in accordance with the guidance in Appendix C and provide this value to the ANSI N14.1 subcommittee in a separate transmittal.
THE CRITICALITY REOUIREMENTS OF 10CFR71.55 " GENERAL REOUIREMENTS FOR FISSILE MATERIAL PACKAGES." /".E STil L MET WITH THE INCREASED ASSAY Li'dIT ON THE 10-TON 48X CYLINDER MODEL 10 CFR 71.55(e), requires that subcriticality be demonstrated considering moderatior by water to the most reactive credible extent and close full reflection of the containment system by water on all sides or such greater reflection of the containment systems as may additionally be provided by the surrounding material of the packaging. Enclosure 1, an excerpt from the
" Safety Analysis Report on the Paducah Tiger Protective Overpack for 10-Ton Cylinders of Uranium Hext.iluoride," KY-665, Revision 1, describes the nuclear criticality safety analyses performed for the Paducah Tiger shipping package. it demonstrates compliance with the performance requirements specified in 10CFR71.55. It is also the basis for the current NRC Certificate of Compliance No. 6553, issued to the Paducah Gaseous Diffusion P! ant (PGDP) for the Paducah Tiger package. The increase in assay does not affect any physical parameters for the package or any test results.
The summary of ORNilTM-11947 (Enclosure 2), section 4.2.6, which is referenced by, concluded that "..the ten-ton UF. Cylinder with 5 wt% 2"U enrichment meets the 10CFR71 criteria for a Fissile Class I package with a Transpon Index (TI) of zero for criticality purposes..." In the past, PGDP had no need to ship material at 5 wt% 2"U assay in the ten-ton cylinders. Thus, the limit of 4.5 wt% 2"U was acceptable. Increasing the l
flexibility of Gaseous Diffusion Plant ' operations, and the assay level of uranium shipped between plants makes it desirable to ship material at 5 wt% 2"U. The information referenced in Enclosure 2 (OIU41/TM-11947) provides a basis for increasing the assay limit to 5 wt%
2"U without additional studies.
F
-o ENCLOSURE 1 Execrpts from Safety Analysis Report on the Paducah Tiger Overpack for 10-Ton Cylinders of Uranium IIcxafluoride l
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