ML21278A313
| ML21278A313 | |
| Person / Time | |
|---|---|
| Site: | 07109309 |
| Issue date: | 10/05/2021 |
| From: | Murray S Global Nuclear Fuel |
| To: | Document Control Desk, Office of Nuclear Material Safety and Safeguards |
| References | |
| M210118 | |
| Download: ML21278A313 (4) | |
Text
GNi= Global Nuclear Fuel Global Nuclear Fuel Scott P. Murray Manager, Facility Licensing 3901 Castle Hayne Road P.O. Box 780 Wilmington, NC 28402 USA M210118 T (910) 819-5950 scott.murray@ge.com October 5, 2021 Attn: Document Control Desk Director, Division of Fuel Managem*ent Office of Nuclear Material Safety and Safeguards US Nuclear Regulatory Commission Washington, DC 20555-0001
Subject:
10 CFR 71.95 - 60 Day Report - RAJ-II Certificate Condition of Approval Not Observed
Reference:
Dear Sir or Madam:
Global Nuclear Fuel - Americas, L.L.C. (GNF-A) in Wilmington, NC hereby submits this report for a discovery involving use of the RAJ-II package in which a condition of approval in USNRC Certificate of Compliance (CoC) (Reference 1) was not observed. Specifically, a GNF-A owned RAJ-I I package was shipped with a condition that failed to meet the requirements for a packaging component (container bolt torque) as required in the package safety analysis report and internal procedures.
An evaluation has determined that this event was of very low safety significance and there was no release of material while using the RAJ-II package with this condition. All other requirements of the CoC were met. An internal condition report was opened to track and remedy the cause of the event.
I am the individual knowledgeable about this event and can provide additional information as needed. If there are any questions regarding this report, please contact me at (910) 819-5950.
Sincerely, J?~A Scott P. Murray, Manager Facility Licensing Attachment Cc: NRC Region II Administrator, Atlanta, GA M. Ruffin, USNRC, RII J. Rowley, USNRC, NMSS SPM 21-028
US NRC M210118 October 5, 2021 Page2 Attachment 10 CFR 71.95- Type B Transportation Package Report USA/9309/B(U)F-96 (1) Brief abstract describing the maior occurrences - (71.95(c)(1)
The RAJ-II package is a rectangular metal box used to transport a maximum of two unirradiated boiling water reactor (BWR) finished fuel assemblies. It is comprised of one inner container and one outer container, both made of stainless steel. The inner container is composed of a double wall stainless steel structure with an alumina silicate thermal insulator filling the gap between the two walls. Both the inner and outer container have a removable lid to allow loading of the contents that are reinstalled and secured with bolts prior to shipment. Internal procedures require these bolts to be securely tightened to a specified torque.
NRC CoC USA/9309/B(U)F-96, Revision 12 (and previous revisions), specifies in condition 6(a) that:
6 (a) The package shall be prepared for shipment and operated in accordance with the Package Operations of Chapter 7 of the application.
GNF-A internal procedure OP 1050.70.205, Rev 8 "Fuel Bundle Packing - Packing Outer Containers" requires a torque of 20 +/- 5 ft-lbs. for the outer container lid bolts.
GNF-A shipped RAJ-II package serial number RA-1274 containing unirradiated fuel assemblies to a customer reactor site without one of the required 24 outer container lid bolts being securely tightened and torqued. There were no incidents or accident conditions during the use of the affected package and no components or systems of the package failed.
(2) Narrative description of the event - (71.95(c)(2) i) Status of components or systems that were inoperable at the start of the event and that contributed to the event; Except for one outer container lid bolt, the affected RAJ-II packaging 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 August 9, 2021, a domestic customer reactor site notified GNF-A that it discovered one of the 24 outer container lid bolts on RA-127 4 was not securely tightened or torqued as required. There were no other RAJ-I I packages 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 system or component failures.
US NRC M210118 October 5, 2021 Page3 iv) The failure mode, mechanism, and effect of each failed component, if known; There were no known system or component failures.
v) A list of systems or secondary functions that were also affected for failures of components with multiple functions; No systems or secondary functions were affected by the improperly tightened and torqued bolt.
- vi) The method of discovery of each component or system failure or procedural error; The improperly tightened and torqued bolt was discovered and reported by a customer reactor site.
vii) For each human performance-related root cause, a discussion of the cause(s) and circumstances; An investigation of the GNF-A loading procedural requirements determined the issue was likely caused by a human performance related issue. There was no requirement for a second verification associated with torquing bolts.
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 affected RAJ-I I package contained two unirradiated boiling water reactor (BWR) finished fuel assemblies. The radioactive material is in the form of solid ceramic pellets with limited solubility and minimal propensity to suspend in air. The proper shipping name was RQ, UN3328, Radioactive Material, Type B(U) Package, Fissile, Class 7, Solid, Uranium Dioxide (Enriched to 20% or less).
(3) Assessment of Safety Consequences and Implications of the Event -
(71.95(c)(3}
Per the RAJ-II safety analysis report, the primary containment of the uranium dioxide fuel inside the package is the fuel rod cladding. The cladding is verified as leak tight prior to any shipment. The RAJ-I I is constructed of two non-containment structures, the outer container (OC) and the inner container (IC). Both the OC and IC are designed to protect the fuel assemblies and fuel rod cladding to maintain containment during accident conditions. The OC consists of a metal wall with shock absorbing devices and vibration isolation mounts for the IC with a primary function of mechanical protection.
The IC's main function is to provide thermal support but also does provide some mechanical protection.
US NRC M210118 October 5, 2021 Page4 The outer container lid bolts are safety category B per NUREG/CR-6407 meaning another component must also fail to create an unsafe condition. There are a total of 24 outer container lid bolts and only one was found not securely tightened in this case. The bolt was still present and not completely absent. A technical evaluation of the impacts of this condition to general package requirements and accident testing conditions concluded that the effectiveness of the package was not significantly reduced due to the single non-tightened OC lid bolt. This conclusion was based on the following three points:
- The lack of evidence of any failed bolts during package drop tests in conjunction with the fact that this is a Level B safety item (2 or more items must fail).
- The redundant structure of the IC and OC containers, along with the integrity of the remaining structure (bolts, vibro-isolation bars, and shock absorbers).
- The relatively minor reduction in overall allowable f.orce before bolts will yield or break.
A 10 CFR 21 evaluation was also performed to determine if the condition could have created a substantial safety hazard or contribute to exceeding a technical specification safety limit. Since the remaining 23 other outer lid bolts are sufficient to meet the intended_function of the mechanical interface, no substantial saf~ty hazard or technical specification violation exists as a result of the condition. As a result, no additional 10 CFR 21 reporting is required.
(4) Corrective actions taken - l71.95lc){4}
- 1) An internal condition report (CR 37520} was opened to track and remedy the cause of the event.
Complete: August 9, 2021
- 2) Revise the internal GNF-A requirements for packing the RAJ-II for shipment to implement a second operator verification step for proper bolt tightening and torque.
Complete: August 11, 2021
- 3) RAJ-II packages prepared for shipment prior to August 11, 2021 and still onsite were released for shipment by the responsible quality function based on inspections and torque verifications of the outer container lid bolts.
Complete: September 8, 2021 (5) Reference to any previous similar.events - l71.95lc}l5}
- GNF-A 10 CFR 71.95 report dated June 26, 2019 (6) qontact - 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.