05000296/LER-2006-003, Regarding Manual Scram in Response to Main Turbine Electro-Hydraulic Control (EHC) System Fluid Leak
| ML062900040 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 10/16/2006 |
| From: | O'Grady B Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 06-003-00 | |
| Download: ML062900040 (8) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 2962006003R00 - NRC Website | |
text
October 16, 2006 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) 50-296/2006-003-00 The enclosed report provides details of a manual reactor scram which occurred on Unit 3. The scram was initiated in response to a fluid leak in the main turbine electro-hydraulic control (EHC) system. All plant systems responded in accordance with the plant design.
In accordance with 10 CFR 50.73(a)(2)(iv)(A), TVA is reporting this event as a manual actuation of the reactor protection system and of containment isolation valves in more than one system. There are no commitments contained in this letter.
Sincerely, Original signed by:
Brian OGrady cc: See page 2
U.S. Nuclear Regulatory Commission Page 2 October 16, 2006 Enclosure cc (Enclosure):
Ms. Margaret Chernoff, Project Manager U.S. Nuclear Regulatory Commission (MS 08G9)
One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 Mr. Malcolm T. Widmann, Branch Chief U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-8931 NRC Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611-6970
U.S. Nuclear Regulatory Commission Page 3 October 16, 2006 WDC:DTL:PSH:BAB Enclosure cc (Enclosure):
B. M. Aukland, POB 2C-BFN M. Bajestani, NAB 1A-BFN A. S. Bhatnagar, LP 6A-C R. H. Bryan, BR 4X-C R. G. Jones, POB 2C-BFN G. V. Little, NAB 1D-BFN R. A. DeLong, SAB 1E-BFN K. W. Singer, LP 6A-C P. D. Swafford, LP 6A-C E. J. Vigluicci, WT 6A-K NSRB Support, LP 5M-C INPO:LEREvents@inpo.org EDMS WT CA - K s:lic/submit/subs/u3 ler 296/2006-03.doc
NRC FORM 366 (6-2004)
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (6-2004)
LICENSEE EVENT REPORT (LER)
(See reverse for required number of digits/characters for each block)
APPROVED BY OMB NO. 3150-0104 EXPIRES 06/30/2007
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 1. FACILITY NAME Browns Ferry Unit 3
- 2. DOCKET NUMBER 05000296
- 3. PAGE 1 OF 5
- 4. TITLE Manual Scram in Response to Main Turbine Electro-Hydraulic Control (EHC) System Fluid Leak
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL NUMBER REV NO.
MONTH DAY YEAR FACILITY NAME none DOCKET NUMBER N/A 08 29 2006 2006-003-00 10 16 2006 FACILITY NAME none DOCKET NUMBER N/A
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §:(Check all that apply)
- 9. OPERATING MODE 1
20.2201(b) 20.2203(a)(3)(i) 50.73(a)(2)(i)(C) 50.73(a)(2)(vii) 20.2201(d) 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 20.2203(a)(1) 20.2203(a)(4) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 20.2203(a)(2)(i) 50.36(c)(1)(i)(A) 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A) 20.2203(a)(2)(ii) 50.36(c)(1)(ii)(A)
X 50.73(a)(2)(iv)(A) 50.73(a)(2)(x) 20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(v)(A) 73.71(a)(4) 20.2203(a)(2)(iv) 50.46(a)(3)(ii) 50.73(a)(2)(v)(B) 73.71(a)(5) 20.2203(a)(2)(v) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(C)
OTHER
- 10. POWER LEVEL 100 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B) 50.73(a)(2)(v)(D) specify in Abstract below or in (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)
VI. CORRECTIVE ACTIONS
A.
Immediate Corrective Actions
The reactor was manually scrammed and the main turbine tripped. Valve realignment associated with the turbine trip isolated the leak location from the rest of the EHC system.
EHC system fluid inventory was restored.
B.
Corrective Actions to Prevent Recurrence(1)
Relative bolt length/hole depths were checked on other similar Unit 3 locations Create/revise maintenance procedure(s) to address verification of clearance between bolt length and hole depth to ensure adequate O-ring compression when a valve is replaced.
VII. ADDITIONAL INFORMATION
A.
Failed or Degraded Components mounting bolt supplied by General Electric B.
Previous LERs on Similar Events 260/1999 Manual Reactor Scram due to an EHC leak The 1999 event on Unit 2 was caused by the failure of a stainless steel tubing welded connection, and the corrective actions associated with this event are not relevant to the mounting bolt length issue of the August 29, 2006 event being reported here.
C.
Additional Information
Browns Ferry corrective action document PER 109756 D.
Safety System Functional Failure (SSFF) Consideration:
This event does not involve a safety system functional failure which would be reported in accordance with NEI 99-02. The manual scram was initiated in response to a malfunction of non-safety related equipment. All safety-related equipment performed in accordance with plant design in response to the event.
E.
Loss of Normal Heat Removal Consideration:
Reactor make-up was continued by the condensate and feed water systems, and decay heat was removed via steaming to the main condenser. There was no loss of normal heat removal condition associated with this scram event.
VIII. COMMITMENTS
None (1) TVA does not consider these corrective actions regulatory commitments. The completion of these actions will be tracked in TVAs Corrective Action Program.