05000296/LER-2003-001, Brown Ferry, Unit 3, Regarding Mode Change Not Allowed by Technical Specifications During Vessel Reassembly
| ML032471002 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 08/26/2003 |
| From: | Bhatnagar A Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 03-001-00 | |
| Download: ML032471002 (8) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 2962003001R00 - NRC Website | |
text
August 26, 2003 U.S. Nuclear Regulatory Commission 10 CFR 50.73 ATTN: Document Control Desk Mail Stop OWFN, P1-35 Washington, D. C. 20555-0001
Dear Sir:
TENNESSEE VALLEY AUTHORITY - BROWNS FERRY NUCLEAR PLANT (BFN) -
UNIT 3 - DOCKET 50-296 - FACILITY OPERATING LICENSE DPR LICENSEE EVENT REPORT (LER) 50-296/2003-001-00 The enclosed report provides details concerning an event during which the reactor mode change requirements of Technical Specifications (TS) Limiting Condition for Operation 3.0.4 were not met. TVA is reporting this event as a condition prohibited by TS in accordance with 10 CFR 50.73(a)(2)(i)(B). There are no commitments contained in this letter.
Sincerely, Original signed by:
Ashok S. Bhatnagar Enclosure
U.S. Nuclear Regulatory Commission Page 2 August 26, 2003 TEA:DTL:BCM:BAB Enclosure cc (Enclosure):
M. J. Burzynski, BR 4X-C J. E. Maddox, LP 6A-C J. Scott Martin, PMB 1A-BFN F. C. Mashburn, BR 4X-C D. C. Olcsvary, LP 6A-C C. L. Root, PAB 1G-BFN J. R. Rupert, LP 6A-C K. W. Singer, LP 6A-C M. D. Skaggs, POB 2C-BFN E. J. Vigluicci, ET 11A-K LEREvents@inpo.org NSRB Support, LP 5M-C EDMS-K S:lic/submit/lers/296-2003-01 RPV Head Bolt Tens.doc
Abstract
On June 30, 2003, Unit 3 was in the latter stages of recovering from a scheduled mid-cycle outage during which the reactor vessel had been disassembled to allow fuel bundle testing. The Reactor Mode Switch had been previously placed in Refuel (Mode 5) to support testing of control rods. Vessel reassembly activities were in progress and the last reactor vessel head closure bolt was tensioned at 0220 hours0.00255 days <br />0.0611 hours <br />3.637566e-4 weeks <br />8.371e-5 months <br />.
With the Reactor Mode Switch in Refuel and all vessel head bolts tensioned, Technical Specifications (TS) Table 1.1-1, Modes, defines the reactor mode as Startup (Mode 2). So, the final tensioning of the head bolts resulted in an unintended reactor mode change from 5 (Refueling) to 2 (Startup). TS Limiting Condition For Operation (LCO) 3.0.4 prohibits ascending mode changes unless all TS equipment required for the mode is Operable. Due to the outage status of the plant, several TS systems required for Mode 2 were not in fully operable status, which resulted in not meeting the requirements of LCO 3.0.4. An oncoming dayshift operator noted that the Reactor Mode Switch was not in the proper position and placed the switch in Shutdown at 0726, which restored compliance with TS.
The root cause of this event was the plant procedure for vessel assembly did not have a notification step to verify mode switch position when the vessel head was tensioned. The procedure has been revised.
This event is being reported as a condition prohibited by TS in accordance with 10 CFR 50.73(a) (2) (i) (B). There was no safety significance associated with the event.
(If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)