ML072850905
| ML072850905 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 10/12/2007 |
| From: | O'Grady B Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| IR-07-001 | |
| Download: ML072850905 (4) | |
Text
October 12, 2007 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Stop: OWFN, P1-35 Washington, D.C. 20555-0001
Dear Sir:
In the Matter of ) Docket Nos. 50-296 Tennessee Valley Authority )
BROWNS FERRY NUCLEAR PLANT (BFN) - UNIT 3 SPECIAL REPORT 296/2007-001 FOR INOPERABLE POST ACCIDENT MONITORING (PAM)
INSTRUMENTATION TVA is providing this PAM report as required by Condition G of Technical Specifications (TS) Limiting Condition for Operation (LCO) 3.3.3.1, Post Accident Monitoring Instrumentation, and LCO in TS 5.6.6, PAM Report. This report informs NRC that the Unit 3 High Range Primary Containment Monitor Recorder (3-RR-90-273) was inoperable for more than 30 days.
BACKGROUND:
The Recorders for the Primary Containment Area High range Radiation Monitors (RMs) 3-RM-90-272A and 3-RM-90-273A are located in the Unit 3 Control Room on Panels 3-9-54 and 3-9-55, respectively. The primary purpose of these monitors is to provide high range radiation monitoring capabilities which are used to indicate the area radiation conditions in the primary containment during accident conditions. Their HI-HI alarms (160 R/hr) alarm in the control room for use by operators in determining the need to invoke site emergency plans (EP). These monitor HI-HI alarm points are below EP classification limits to ensure the safety of the public.
U. S. Nuclear Regulatory Commission Page 2 October 12, 2007 DESCRIPTION OF EVENT:
On August 29, 2007, the recorder for the 3-RM-90-273A monitor was declared inoperable due to allow the implementation of Design Change Notice (DCN) 66228, stage 13. This DCN replaced an obsolete Yokogawa strip chart recorder with a new Westronics paperless recorder for the subject radiation monitor. Upon completion of the installation of the new Westronics recorder, post modification testing (PMT) was conducted.
During the PMT, the radiation monitors analog output module for Primary Containment Radiation to the recorder 3-RR-90-273A was unable to be calibrated into proper tolerance on the 10E+7 R/Hr scale. This placed the monitor in a degraded state but still able to perform its design function (i.e., alerting Operations personnel of a HI-HI alarm condition). In BFNs warehouse inventory, there was one analog output module; however, this module did not have the appropriate qualification documentation. After much searching, a new analog output module was obtained and was shipped to BFN from Peach Bottom Nuclear Plant through a third-party vendor.
Due to the delay to locate a qualified analog output module, the 30-day LCO time limit was exceeded on September 28, 2007.
PREPLANNED ALTERNATE METHOD OF MONITORING:
Primary Containment Radiation Monitor 3-RM-90-272A is the redundant monitor which also monitors Primary Containment area radiation (high range). It was utilized as an alternate method of monitoring until 3-RM-90-273A could be returned to operable status. This monitor (3-RM-90-272A) provides accurate indication of radiological conditions in the drywell up to 10E+7 Rem/hour.
PLANS AND SCHEDULE FOR RESTORING THE INSTRUMENT CHANNEL:
The newly procured analog output module was installed and PMT was performed. On October 10, 2007, the recorder was declared operable and the LCO exited.
U. S. Nuclear Regulatory Commission Page 3 October 12, 2007 There are no regulatory commitments contained in this letter.
If you have any questions, please telephone James Emens at (256) 729-7658.
Sincerely, Original signed by:
Brian OGrady cc:Regional Administrator U.S. Nuclear Regulatory Commission Sam Nunn Atlanta Federal Center 61 Forsyth Street S.W., Suite 23T85 Atlanta, Georgia 30303-8931 Mr. Stephen C. OConnor, Interim Branch Chief U.S. Nuclear Regulatory Commission Sam Nunn Atlanta Federal Center 61 Forsyth Street S.W., Suite 23T85 Atlanta, Georgia 30303-8931 NRC Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611-6970 Ms. Eva A. Brown, Project Manager U.S. Nuclear Regulatory Commission (MS 08G9)
One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739
U. S. Nuclear Regulatory Commission Page 4 October 12, 2007 JEE:JEW:BAB cc: Gordon Arent, Unit 2, EQB Bldg-WBN W. R. Campbell, LP 6A-C R. H. Bryan, Jr., LP 4J-C D. C. Matherly, Jr., BFT 2A-BFN J. C. Fornicola, LP 6A-C R. G. Jones, POB 2C-BFN G. V. Little, NAB 1D-BFN R. F. Marks, Jr., PAB 1C-BFN B. A. Wetzel, BR 4X-C B. J. OGrady, PAB 1E-BFN E. J. Vigluicci, ET 11A-K NSRB Support, LP 5M-C EDMS WT CA-K, s:lic/submit/subs/Special Report 10.2007.doc