ML22070B112
| ML22070B112 | |
| Person / Time | |
|---|---|
| Site: | 07109362 |
| Issue date: | 03/11/2022 |
| From: | Murray S Global Nuclear Fuel |
| To: | Document Control Desk, Office of Nuclear Material Safety and Safeguards |
| References | |
| M220039 | |
| Download: ML22070B112 (5) | |
Text
GNii= Global Nuclear Fuel Global Nuclear Fuel Scott P. Murray Manager, Facility Licensing 3901 Castle Hayne Road P.O. Box 780 Wilmington, NC 28402 M220039 USA T(910) 819-5950 March 11 , 2022 scott.murray@ge.com Director, Division of Fuel Management Office of Nuclear Material Safety and Safeguards U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Attn: Document Control Desk
Subject:
10 CFR 71.95- 60 Day Report - DN30 Condition of Approval not Observed
References:
- 1) DOT Certificate USA/9362/AF-96, Revision 1, 9/24/2021
Dear Sir or Madam:
Pursuant to 10 CFR 71.95(a)(3), Global Nuclear Fuel - Americas, LLC (GNF-A) submits this report for discovery of a uranium hexafluoride (UF6) transportation package that did not conform with the conditions of approval in the NRC Certificate of Compliance (CoC) (Reference 2) .
.In December 2021, GNF-A shipp*ed a Model 308 cylinder with a solid residual heel of enriched UF6 in a DN30 transportation package. Co"ndition 7(a) of the DN30 NRC Certificate of Compliance requires in part that the protective structural packaging (PSP) be prepared for shipment in accordance with operating procedures of Chapter 1.7 of the application. It was subsequently reported by the consignee that upon receipt, one of the overpack locking mechanisms was not properly secured on PSP serial number UREJ870217.
This nonconformance is associated with a package design feature. An evaluation has determined that this deficiency was of low safety significance and there was no reduction in effectiveness of the DN30 package. All other requirements of the CoC were met.
The attachment to this letter provides the required details of this report.
I am the individual knowledgeable about this event and can provide additional information as needed. If you have any questions regarding this matter, please contact me at (910) 819-5950.
Sincerely, s&:~:~l(/~
Facility Licensing r
- US NRC March 11 , 2022 M220039 Page2
Attachment:
10 CFR 71.95- Type A Transportation Package Report (USA/9362/AF-96) cc: NRC Region II Administrator, Atlanta, GA J. Rivera Ortiz USNRC, RII J. Rowley, USNRC, NMSS Daher Nuclear Technologies GmbH (DN30 Certificate Holder)
SPM 22-013
US NRC March 11 , 2022 M220039 Page 3 Attachment 10 CFR 71.95-Type A Transportation Package Report (USA/9362/AF-96)
(1) Brief abstract describing the maior occurrences
,. - l71.95lc}(1)
The DN30 package is used to transport unirradiated commercial grade uranium, in the form of UF6, with a U-235 mass percentage not to exceed 5 weight percent - as defined in NRG Certificate of Compliance (CoC) USA/9362/AF-96, Revision 3 contents (b)(1).
NRG CoC USA/9362/AF-96, Revision 3 (and previous revisions), specifies in condition 7(a) that:
7 (a) The package shall be prepared for shipment and operated in accordance with the Operating Procedures of Chapter 1.7 of the application.
DAHER handling instruction 0023-HA-2015-001, Rev 5 "Use and Handling of the DN30 Package", Step L.15 includes instructions regarding securing the six corresponding outer lid closure devices.
(2) Narrative description of the event - l71.95lc}(2) it) Status of components or systems that.were inoperable at the start of the event and that contributed to the event; The affected DN30 protective structural packaging (PSP) was properly prepared by GNF-A in accordance with applicable procedures and regulations before being shipped. There were no inoperable components or systems.
ii) Dates and approximate times of occurrences; On December 3, 2021, GNF-A made a shipmenmt of four DN30 PSPs to" URENCO Netherlands (UNL) each with an empty 308 cylinder containing a solid residual heel of enriched UF6. Subsequently, UNL discovered that one of the six pins in the mortise-and-tenon locking mechanism on DN30 PSP serial number UREJ870217 was not fully inserted as required. As confirmed by UNL, all six mortise-and-tenon pins had the locking bolts properly torqued, but one pin was not fully engaged in the joint.
On January 19, 2022, GNF-A was informed by URENCO of this discovery. There were no other PSPs in the shipment that had this nonconformance.
iii) The cause of each component or system failure or personnel error, if known; There were no known component or system failures. On December 2, 2021, prior to shipment, a GNF-A operator completed a DN30 functional test checklist which included a verification signoff that the closure device pin on this PSP was properly inserted. The apparent cause is assigned as a human performance deficiency.
US NRC March 11 , 2022 M220039 Page 4 iv) The failure mode, mechanism, and effect of each failed component, if known; The two halves of the DN30 PSP are secured by a closure system consisting of six robust mortise-and-tenon like devices. The two parts of each mortise-and-tenon system have four teeth with a hole in the center. When closed, the two halves are connected by a pin inserted into these holes. This pin is secured by a bolt. The system is designed to prevent excessive relative movements of the top and bottom halves during transport.
On Df':J30 PSP UREJ870217, it was subsequently reported by_the consignee that upon
. receipt, one locking pin was not fully inserted, and the handle was not properly secured.
v) A list of systems or secondary functions that wefe also affected for failures of components with multiple functions; No systems or secondary functions were affected by the improperly secured pin on the closure device.
~ vi) The method of discovery of each component orsystem failure or procedural error; The improperly secured pin was discovered and reported by URENCO.
vii) For each human performance-related root cause, a discussion of the cause(s) ancf circumstances; Investigation of the GNF-A inspection and loading procedural requirements for this PSP found that the requirement to check the installation of the locking pins (six in total) was completed and found acceptable as documented by the qualified operator on a DN30 pre-shipment checklist dated December 2, 2021. The suspected apparent cause is that one of six mortise-and-tenon pins was not fully engaged when the GNF-A operator torqued the final locking bolts. One pin was found to be about 20% out of proper insertion position when received at UNL with the locking bolt properly torqued.
Review of the operation procedure found that self-check and peer check is not utilized. Actions were taken to strengthen the operating procedure and log sheet to perform and document a peer check of this task ..
viii) The manufacturer and model number (or other identification) of each component that failed during the event; There were no component failures.
ix) For events occurring during use of a packaging, the quantities and chemical and physical form(s) of the package contents.
The enclosed cylinder had been emptied to the extent practical and contained a solid heel quantity of UF6. The proper shipping name was UN2977, Radioactive Material, Uranium Hexafluoride, Fissile, Class 7 (8) (Enriched to 20% or less). The cylinder was shipped in a USA/9362/AF-96, DN30 protective structural package (P_ SP).
US NRC March 11 , 2022 M220039 Page 5 (3) Assessment of Safety Consequences and Implications of the Event -
cz1.9~Cc)(3)
Discussions with the current DN30 certificate holder (DAHER) indicate the package performance was tested with all six closure devices fully engaged.~No evaluation or testing was performed with less than a full compliment of six fully engaged closure device pins.
Based on the CoC holder's response, GNF-A is unable to quantify whether a single less than fully engaged locking pin is a condition which causes a significant reduction in the package effectiveness. However, GNF's review of the package mechanics concluded that the partially engaged closure device pin has no effect on the closure joint mechanical functionality since the pin was still 80% engaged making the joint functional. A photo provided by URENCO shows the pin to be about 20% out of position. The condition was present on only one of the six closure devices on the package.
The integrity of the package was not compromised. The enclosed cylinder contained only solid heel quantities of UF6, the valve was fully functional, and the cylinder was leak checked prior to being shipped.
There were no issues reported during transport. As a result, GNF-A has determined that this deficiency was of low safety significance and there was no significant reduction*in effectiveness of the D_N30 package.
(4) Corrective actions taken - (71.95(c)(4)
No additional corrective actions. There were no other issues reported with DN30 lid locking mechanism.
(5) Reference to any previous similar events - l71.95(c)(S)
This is the first known instance of an improperly installed DN30 locking pin discovered upon receipt.
(6) Contact - l71.95lc)(6)
Please contact Scott Murray at (910) 819-5950 for any additional information about this report.
(7) Extent of Exposure to Radiation - l71.95lc)(7)
No individuals were exposed to radiation or radioactive material due to this issue. There was no leakage of contents due to the nonconformance.