ML24151A352
| ML24151A352 | |
| Person / Time | |
|---|---|
| Site: | 07109218, 07109279 |
| Issue date: | 05/30/2024 |
| From: | Sellmer T Salado Isolation Mining Contractors (SIMCO) LLC |
| To: | Office of Nuclear Material Safety and Safeguards, Document Control Desk |
| References | |
| TS:24:03014 | |
| Download: ML24151A352 (1) | |
Text
TS:24:03014 May 30, 2024 ATTN: Document Control Desk Director, Division of Fuel Management Office of Nuclear Material Safety and Safeguards U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
Subject:
REPORT PURSUANT TO 10 CFR 71.95
Dear Ms. Helton:
Salado Isolation Mining Contractors (SIMCO) LLC, on behalf of the U.S. Department of Energy Carlsbad Field Office (DOE/CBFO), submits this letter to report a condition pursuant to 10 CFR 71.95 regarding the use of the Type B packaging model numbers TRUPACT-II and HalfPACT. These packagings operate under the U.S. Nuclear Regulatory Commission (NRC)
Certificate of Compliance (CofC) Numbers 9218 and 9279. During the shipment of contact-handled (CH) transuranic (TRU) waste to the Waste Isolation Pilot Plant (WIPP) from Lawrence Livermore National Laboratory (LLNL), the conditions in Section 7 of CofCs Nos. 9218 and 9279 were not followed in their entirety.
Following is a description of the events, reported in accordance with 10 CFR 71.95 (c):
(1) A brief abstract describing the major occurrences during the event, including all component or system failures that contributed to the event and significant corrective action taken or planned to prevent recurrence.
Three CH-TRU waste shipments made between September 29, 2022, at 11:40 and September 16, 2023, at 7:42 (MST) from LLNL to WIPP included 29 55-gallon drum payload containers that were assigned to incorrect CH-TRUCON codes and payload shipping categories. More specifically, the packaging configurations described by the assigned CH-TRUCON codes and shipping categories did not reflect the actual presence of 5-quart filtered plastic buckets used to package waste in each of the payload containers.
There were no major occurrences during the events and no component or system failures that contributed to the events. However, due to the use of incorrect CH-TRUCON codes and shipping categories, the conditions in Section 7 of CofC Nos. 9218 and 9279 were not followed in their entirety and resulted in these shipments traveling to WIPP in a non-compliant condition.
The data for the 29 containers were evaluated upon discovery of the CH-TRUCON code and shipping category assignment errors and were determined to not represent a safety violation.
When evaluated using the shipping categories associated with the correct packaging
Document Control Desk CP:24:03014 configurations, the associated flammable gas generation limits are met for each payload container ensuring that 5% hydrogen concentration was not exceeded in any innermost waste confinement layer.
The following corrective/preventive actions were implemented to preclude recurrence:
x A review was performed to identify all potential containers that had waste packaged in these 5-quart filtered plastic buckets.
x Certification for shipment of containers in the associated waste streams was temporarily suspended until an extent of condition was completed.
x Correct CH-TRUCON codes and shipping categories were developed to account for the presence of the 5-quart filtered plastic buckets.
CH-TRUCON code and shipping category assignments will be reassessed and corrected in the WDS compliance software for container certification following determination and documentation of the correct packaging configuration.
(2) A clear, specific, narrative description of the event that occurred so that knowledgeable readers conversant with the requirements of part 71, but not familiar with the design of the packaging, can understand the complete event. The narrative description must include the following specific information as appropriate for the particular event.
The NRC issued CoC Nos. 9218 and 9279 Condition 7 states: Each payload container must be assigned to a shipping category in accordance with CH-TRAMPAC, Rev. 6." Section 5.1.1 of the CH-TRAMPAC requires that each container be assigned to a payload shipping category in an approved content code, based on the waste material type, total resistance to gas release, and the shipping duration. The total resistance to gas release is determined by totaling the individual resistance factors for the packaging configuration confinement layers, the payload container (including a rigid liner, as applicable), and the load type associated with the shipping period. CH-TRU Payload Appendix 3.8 specifies that For any other type of confinement layer (other than the types of plastic bags or metal or other rigid containers described) used at the sites, a minimum hydrogen release rate (mol/s) shall be determined, by testing or analysis, consistent with Appendices 6.7 and 6.13.
In this case, 29 containers shipped from LLNL to WIPP were assigned to an incorrect content code (CH-TRUCON code) and payload shipping category that did not account for the hydrogen release rate of the filtered plastic bucket, resulting in an evaluation against incorrect flammable gas generation limits.
Independent evaluations using the flammable gas generation limits associated with the correct packaging configuration for each of the 29 containers were performed by WIPP M&O Payload Engineers and showed that limits are met and the hydrogen concentration in the innermost confinement layer did not exceed 5% during transport.
All other conditions required for the operation and shipment of the packages in accordance with the CofC were adhered to.
Document Control Desk CP:24:03014 (2)(i) Status of components or systems that were inoperable at the start of the event and that contributed to the event; This criterion is not applicable to the events because there were no components or systems that were inoperable at the start of the events.
(2)(ii) Dates and approximate times of occurrences; The three shipments were made between September 29, 2022, at 11:40, and September 16, 2023, at 7:42 (MST).
(2)(iii) The cause of each component or system failure or personnel error, if known; No components or systems failed.
(2)(iv) The failure mode, mechanism, and effect of each failed component, if known; This criterion is not applicable to the events because no components failed.
(2)(v) A list of systems or secondary functions that were also affected for failures of components with multiple functions; This criterion is not applicable to the events because no components failed.
(2)(vi) The method of discovery of each component or system failure or procedural error; No components failed. The incorrect assignment of the CH-TRUCON codes and payload shipping categories for multiple containers was discovered when a Visual Examination Expert (VEE) at LLNL requested clarification from the SIMCO Payload Engineer on the use of a 5-quart filtered plastic bucket as a confinement layer for waste packaging. As required by CH-TRU Payload Appendix 3.8, the SIMCO Payload Engineer performed physical measurements and corresponding analytical hydrogen diffusion calculations to determine a minimum hydrogen release rate (mol/s) for the filtered plastic bucket confinement layer. It was then discovered on April 30, 2024, that this filtered plastic bucket had already been used to package waste in 55-gallon drum payload containers without being identified as a layer of confinement in the associated Non-Destructive Examination (NDE) waste characterization documentation. This-documentation omission resulted in the containers being assigned a CH-TRUCON code that did not describe the presence of the filtered plastic bucket and a payload shipping category that did not include the hydrogen release rate associated with this confinement layer.
(2)(vii) For each human performance-related root cause, a discussion of the cause(s) and circumstances; After a review of all relevant procedures and e-mail correspondences, the human performance-related root cause was determined to be inadequate training of NDE operators, who determined that the filtered plastic bucket was not a confinement layer. This was an incorrect interpretation of the CH-TRU Payload Appendix 3.8 definition of a confinement layer.
Document Control Desk CP:24:03014 (2)(viii) The manufacturer and model number (or other identification) of each component that failed during the event; and Manufacturer and model numbers associated with component failure are not applicable because no components failed.
(2)(ix) For events occurring during use of a packaging, the quantities and chemical and physical form(s) of the package contents.
The 29 containers were shipped in three TRUPACT-II/HalfPACT shipments. Aside from the use of incorrect CH-TRUCON codes and payload shipping categories for 29 of the payload containers, all other conditions required for the operation and shipment of the packages in accordance with the CofC were adhered to. A detailed listing of all quantities for each shipment can be provided upon request.
(3) An assessment of the safety consequences and implications of the event. This assessment must include the availability of other systems or components that could have performed the same function as the components and systems that failed during the event.
There were no systems or components that failed during the events. Independent evaluations performed for the 29 containers accounting for the presence of the filtered plastic bucket as a layer of confinement concluded that none exceeded the corrected flammable gas generation limits ensuring that none exceeded 5% hydrogen concentration in the innermost confinement layer during transport. There were no safety consequences or implications of the events.
(4) A description of any corrective actions planned as a result of the event, including the means employed to repair any defects, and actions taken to reduce the probability of similar events occurring in the future.
In addition to the interim corrective actions identified in (1) above, additional training related to identifying and accounting for layers of confinement will be administered by the SIMCO Central Characterization Program (CCP) to NDE personnel and Site Management Representative (SMRs).
(5) Reference to any previous similar events involving the same packaging that are known to the licensee or certificate holder.
Salado Isolation Mining Contractors letter number TS:23:03019 dated 5/23/2023: Incorrect CH-TRUCON codes assigned to 17 containers.
Salado Isolation Mining Contractors letter number TS:23:03016 dated 4/19/2023: Incorrect CH-TRUCON codes assigned to 48 containers.
Nuclear Waste Partnership letter number CP:15:01116, dated 6/11/2015: Incorrect waste stream identified.
Document Control Desk CP:24:03014 Washington TRU Solutions letter number CP:13:01449, dated 10/8/2013: Incorrect CH-TRUCON code assigned to seven drums.
Washington TRU Solutions letter number CP:12:01464, dated 9/27/2012: Incorrect CH-TRUCON code assigned to a single 55-gallon drum.
Washington TRU Solutions letter number CP:12:01074, dated 1/26/2012: Incorrect content code assigned to 13 drums.
(6) The name and telephone number of a person within the licensee's organization who is knowledgeable about the event and can provide additional information.
T.E. Sellmer, Manager, SIMCO, Packaging and Information Systems, (575) 234-7396 or (575) 302-7583 (7) The extent of exposure of individuals to radiation or to radioactive materials without identification of individuals by name.
There were no exposures to individuals as a result of the event. All pre-shipment surveys satisfied the regulatory dose rate limits.
If you have any questions or require additional information regarding this report, please contact me at (575) 234-7396 or (575) 302-7583.
Sincerely, T. E. Sellmer, Manager Packaging and Information Systems TES:clm cc: L. F. Gelder, SRCC ED K. E. Princen, CBFO ED J. Shenk, EM-4.24 ED K. E. Princen, CBFO ED D. M. Smith, CBFO ED A. J. Walker, CBFO ED B. H. White, USNRC ED TODD SELLMER (Affiliate)
Digitally signed by TODD SELLMER (Affiliate)
Date: 2024.05.30 09:23:51 -06'00'