ML101820579
| ML101820579 | |
| Person / Time | |
|---|---|
| Site: | University of Missouri-Columbia |
| Issue date: | 06/29/2010 |
| From: | Rhonda Butler, Foyto L Univ of Missouri - Columbia |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML101820579 (2) | |
Text
UNIVERSITY of MISSOURI RESEARCH REACTOR CENTER June 29, 2010 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Mail Station P1-37 Washington, DC 20555-0001
REFERENCE:
Docket 50-186 University of Missouri-Columbia Research Reactor Amended Facility License R-103
SUBJECT:
Written communication as specified by 10 CFR 50.4(a) regarding correcting Stack Effluent Information in University of Missouri Research Reactor Operations Annual Report-Calendar Year 2009 The purpose of this letter is to correct a discrepancy in the University of Missouri Research Reactor (MURR) Operations Annual Report for calendar year 2009. On Page VII-2 of the Report, Argon-41 stack effluent was reported at 70.3% of the MURR Technical Specification (TS) limit. The value only applied to the time that the Argon-41 exhaust was determined by the NMC RAK stack monitor. The correct value for all of calendar year 2009 should have been 54.9%.
Two (2) radiation monitors are installed in the MURR facility ventilation system exhaust stack to continuously measure stack effluent releases. While both radiation monitors are typically in service, only one is required to be in operation as per the Technical Specifications (TS 3.4.a). The NMC RAK stack monitor, which is normally MURR's monitor of record for Argon-41 releases, was out-of-service for several extended periods during the year as we installed and tested its eventual replacement-a Model Lab Impex stack monitor. During those out-of-service periods, Health Physics reverted to MURR's original method of monitoring Argon-41 releases to the environment by collecting stack exhaust samples in Maranelli canisters and quantifying the argon by analysis on a sodium iodide detector. This method has historically yielded a lower average concentration. This year's values were typical of previous year's values.
The two methods ultimately require a different set of calculations and are tracked on separate EXCEL spreadsheets. The Argon-41 average concentration and total release were correctly calculated and reported; however, the percent of the TS limit was calculated and reported incorrectly. Only data from the NMC RAK stack monitor was used. We did not take into account the Maranelli air sample/sodium iodide data. Therefore, the 70.3% originally reported is the average concentration of the data collected only by the NMC RAK stack monitor, and not for the entire year using both methods.
74Q;ý)D 1513 Research Park Drive Columbia, MO 652 11 Phone: 573-882-4211 Fax: 573-882-6360 Web: http://web.missouri.edu/-murrwww Fighting Cancer with Tomorrow's Technology
If there are any questions regarding this letter, please contact me at (573) 882-5276 or foytol(Ži-missouri.edu.
ENDORSEMENT:
Sincerel Reviewed and Approved, Leslie P. Foyto Ralph A. Butler, P.E.
Reactor Manager Director LPF/djr xc:
Mr. Alexander Adams, U.S. NRC Mr. Craig Bassett, U.S. NRC