ML24184A113
| ML24184A113 | |
| Person / Time | |
|---|---|
| Site: | University of Missouri-Columbia (R-103) |
| Issue date: | 07/02/2024 |
| From: | Sanford M Univ of Missouri - Columbia |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| 24-02 | |
| Download: ML24184A113 (1) | |
Text
{{#Wiki_filter:E!J University of Missouri July 2, 2024 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
REFERENCE:
Docket No. 50-186 University of Missouri-Columbia Research Reactor Renewed Facility Operating License No. R-103 MU Research Reactor Division of Research, Innovation & Impact 1513 Research Park Drive Columbia, MO 65211 PHONE 573-882-4211 WEB murr.missouri.edu
SUBJECT:
Written communication as required by University of Missouri Research Reactor Technical Specification 6.6.c(3) regarding a deviation from Technical Specification 3.10.d The attached document provides the University of Missouri-Columbia Research Reactor (MURR) Licensee Event Report (LER) for a deviation from Technical Specification 3.1 0.d that was discovered and reported to the NRC by telephone on June 18, 2024, as an Abnonnal Occurrence as defined in Technical Specification 1.1 b., "operation in violation of Limiting Conditions for Operations established in Section 3.0." This document is the written report required as a fo11ow-up to that communication. If you have any questions regarding this report, please contact Ron Astrino, the facility Reactor Manager, at (573) 882-5118. Matt Sanford Reactor Facility Director Enclosure cc: Mr. Mun Choi, President, University of Missouri Reactor Advisory Committee Reactor Safety Subcommittee Ms. Jessica Lovett, U.S. Nuclear Regulatory Commission Mr. Edward Helvenston, U.S. Nuclear Regulatory Commission Mr. Andrew Waugh, U.S. Nuclear Regulatory Commission
Enclosure U.S. Nuclear Regulatory Commission July 2, 2024 Licensee Event Report No. 24 July 2, 2024 University of Missouri Research Reactor Introduction MURR operates a train of three hot cells (HC-01 lA, B, and C) used to process radioiodine from tellurium targets into a radiochemical ultimately used as a raw material in 1-131 based radiophannaceuticals. MURR's technical specifications contain limits and conditions for the operation of these cells and their local exhaust ventilation. The iodine-131 exhaust system feeds into the main facility exhaust system and has continuous effluent monitoring for iodine. Each hot cell is equipped with two trains of filters (Bank A and Bank B), each train consisting of one in cell filter (not eligible to count toward TS 3.1 0.d compliance) and nine external filters (six charcoal and three HEPA). One train is normally maintained in service (see attached schematic) while the other is on stand-by off service. Each in-service charcoal bank is expected to have greater than 99% efficiency for 1-131 removal from the exhaust stream. This expected efficiency for each charcoal filter is designed to meet Technical Specification 3.10.d, which states "At least three (3) charcoal filter banks having an efficiency of 99% or greater shall be operable when processing iodine-131 in the iodine-13 1 processing hot cells." Description of Event While investigating the issues related to LER 24-01, a noncompliance with Technical Specification 3.1 0.d was discovered. This discovery was communicated to the NRC by telephone as required by Technical Specification 6.6.c(l) on June 18, 2024. This document provides the written follow-up report required by Technical Specification 6.6.c(3). During the investigation, it was detennined that during the period from July 2022 to April 2024, three (3) individual filters each operating at greater than 99% efficiency were not in service. Filter banks 2 and 3 for each hot cell were operating with charcoal filters having >99% efficiency. Filter banks 4, 5, and 6 were operating with charcoal filters having >98% efficiency, meaning they were not eligible for consideration regarding TS 3.10.d. Bank 3-3, had a charcoal filter installed having chemical efficiency "~J, 1lJJlt1>P.tractor-measured mechanical efficiency of 99.99%. However, MURR engineering ,'~aluati.on i~fo.e d a small bypass flow through the off-service filter train, rendering filter 3-3 ineligible V, ~--,. .,..... *~...,~or c~jallC@ ~a TS 3.10.d.
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eil 31 was performed weekly during the period prior to April 18, 2024. During the ': "S l peO~e&,:@u .:was not in compliance with Technical Specification 3.10.d, there were three ~-;~:ftddiH~m ctls~(~ilters in the exhaust stream from the iodine processing hot,cells (banks 4, 5, and 6), ~,,/<dlch ~th c~~t filters having efficiencies greater than 98%. If these banks had >99% efficient 'c!Ka~114\)-,~~ 'as required by Technical Specifications and expected per the Supplemental LER 2017-03 dated May 16, 2017, the configuration would have been compliant. While the cumulative iodine removal efficiency of banks 4, 5, and 6 each at >98% in series was equivalent to a single charcoal filter having an efficiency for iodine removal of 99.9992%, the configuration did not meet the TS statement requiring a third single filter with >99% efficiency. Several detectors were monitoring the Iodine processing suite containing hot cells HC-1 lA, B and C during the period from July 2022 through May 2024, including the Off-Gas (Stack) Radiation Monitor per Technical Specification 3.10.c. Additional in-service monitors included a Duct Monitor and the Almo-6 monitors. No in-service exhaust system monitors indicated abnormal rises in iodine levels during this period. Pagelof3
Enclosure U.S. Nuclear Regu latory Commission July 2, 2024 Root Cause The root cause of the non-compliance with Technical Specification 3.1 0.d was inadequate adherence to procedure RCP-PSO-035, "Material and Document Control Program for Carbon Adsorbers used in association with Radioiodine (l-131) Production." This procedure was written to ensure the charcoal filters in use for the iodine-131 exhaust system met the requirements of MURR Technical Specifications 3.1 0.d and the commitments made in Supplemental LER 17-03 to have charcoal filters with iodine removal efficiency of at least 99.1 % in banks 2, 3, 3-3, 4, 5, and 6. The non-compliance regarding Technical Specification 3.10.d also revealed a weakness in the implementation surveillance required by Technical Specification 4.1 0.e. The responsibility for adhering to this procedure had been transferred internally to Facility Operations Staff in 2022 and then to Work Control Staff in June 2023. These transfers of responsibility were not conducted with effective turnover regarding the Technical Specification 3.1 0.d requirements or understanding of the commitment to procure and install charcoal filters having efficiency of at least 99.1 % that was made in the Supplemental LER 17-03 letter to NRC dated May 16, 2017. Corrective Actions The non-compliant condition was corrected June 21, 2024, by installing 99.45% efficient charcoal filters in banks 3-3A, 3-3B, 4A, 5A and 6A. Charcoal filters with efficiency of 99.42% were installed in banks 2 and 3 January 29, 2024. CAP-24-0192 was entered into the MURR Corrective Action Program May 14, 2024, to capture the details of the failure to meet the procedural requirements of RCP-PSO-035, specifically with the need to meet Technical Specification 3.1 0.d and the commitments made in Supplemental LER 2017-03 dated May 16, 2017, that all charcoal bank adsorbers would have iodine removal efficiency of at least 99.1 %. Procedure RCP-PSO-035 was updated June 17, 2024, and the persons with responsibilities in the procedure were instructed of the need for attention to detail regarding the material control of the charcoal adsorbers for the 1-131 exhaust system. Compliance Procedure CP-38, "Verify 1-131 Processing Hot Cell Charcoal Filter Efficiency and Service Life," was updated June 24, 2024 to improve the direction given for meeting the intent of Technical Specification 4.1 0.e is met. Because of the bypass issues discovered with Bank 3-3 isolation dampers, this charcoal bank will not be considered eligible to meet Technical Specification 3.10.d at this time, but MURR staff will continue to have Bank 3-3 charcoal filter replaced on its nonnal schedule. Safety Analysis While the configuration of the filter trains during the reference period did not meet the requirement of TS 3.1 0.d, evaluation of the charcoal filters that were in service in banks 4, 5, and 6 showed that these filters considered in series, had an equivalent iodine removal efficiency of greater than 99% efficiency. There is therefore no reason to expect a risk of release beyond that contemplated in the Technical Specifications for the iodine ventilation system. Supporting this reasoning, the exhaust system radiation monitors that were in service during the period of non-compliance did not indicate abnormal rises in iodine levels in the exhaust system. The non-Page 2 of 3
Enclosure U.S. Nuclear Regulatory Commission July 2, 2024 compliance during the pe1iod July 2022 to April 2024 therefore did not result in an elevated risk to the health and safety of the MURR staff or the public. If there are any questions regarding this LER, please contact me at (573) 882-5118. I declare under penalty of perjury that the foregoing is true and correct. Sincerely, 1t~)_. 1 Ronald M Astrino Reactor Manager ENDORSEMENT: Reviewed and Approved, }!( atj ~ft-{ Matt Sanford Reactor Facility Director Page 3 of 3
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-87 DUCT L_ _J Fll TERS V-59 V-57 '. V-68 V-54 V-55 V-61 HC..11 EF-2 V-53 299T & 299U OUTLET FILTERS r--{>~~ I I l ~ e ____,__,_,--,j (4) FFU'S ~ i V-82 22 22-2462 ADD GB-35 TO RM 1990 DGN 21 21-1438 ADD EXHAUST LINE FROM HC-11 PNEUMATIC CABINET DGN Changed labels on HC-11 A Bank in-cell filters from HEPA to H/C lo 20 denote they are now a HEPA / Charcoal combination. And removed DGN the dashed llne rectangles around all Bank 1 In-cell filters on HC-11A, HC-11 B & HC-11 C REV. NO. DESCRIPTION DR. BY 1131/2023 6/3/2021 11/23/2020 DATE i RAO WASTE BARREL Rm 299U ~NOTE1 DHC-4B f' INLET ~ ,.,, ~T X DHC-3B FILTERS
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~ Es i ~ V-85 ~ GB-33 V-79 ~ Rm 299V V-65 -J-- ~ " a:: ;, \.1 V-84 O !i- 0 i <C 5 w ~ a:: ~ u LEGEND: NORMALLY CLOSED ~ z r-<( NORMALLY OPEN N 0 HEPA FILTER ~ I r- ~ CHARCOAL FILTER ~ w HEPNCHARCOAL FILTER ~ 0 I CONSTANTVOLUME (cvi__ 0 u coNTRoL vALVE rY1 <( Cf) CENTRIFUGAL FAN Cf' r-r-PRESSURE TRANSMITTER -8' Cf) Cf) BACK DRAFT DAMPER l/ I <( :::J MAGNEHELIC GAUGE 8 1 w <( METASYS PRESSURE I co I 1 ), FILTER BANKS IN PARALLEL CONFIGURATION NORMALLY HAVE ONE SET OF FILTERS ISOLATED. TRANSMITTER METASYSFLOW STATION ~ ~ w ~i:~~~~~;~L;~~ "BANK'
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