05000382/LER-2011-001, Regarding Waste Gas System Oxygen Exceeded Technical Specification Allowed Duration
| ML11109A116 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 04/16/2011 |
| From: | Steelman W Entergy Nuclear South |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| W3F1-2011-0028 LER 11-001-00 | |
| Download: ML11109A116 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 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)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 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 |
| 3822011001R00 - NRC Website | |
text
Entergy Nuclear South Entergy Operations, Inc.
17265 River Road Killona, LA 70057-3093 Tel 504 739 6685
'"ýEntergy Fax 504 739 6698 wsteelm@entergy.com William J. Steelman Licensing Manager Waterford 3 W3F1-2011-0028 April 16, 2011 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001
Subject:
Licensee Event Report 2011-001-00 Waterford Steam Electric Station, Unit 3 (Waterford 3)
Docket No. 50-382 License No. NPF-38
Dear Sir or Madam:
Entergy is hereby submitting Licensee Event Report (LER) 2011-001-00 for Waterford Steam Electric Station Unit 3. This report provides the details associated with a failure to meet Technical Specification requirements to reduce oxygen concentration in the Waste Gas Holdup System to within limits within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.
This report contains no new commitments. Please contact William Steelman, Manager, Licensing at (504) 739-6685 if you have questions regarding this information.
Sincerely, WJS/MEM Attachment: Licensee Event Report 2011-001-00
W3F1-2011-0028 Page 2 cc:
Mr. Elmo E. Collins, Jr.
Regional Administrator U. S. Nuclear Regulatory Commission Region IV 612 E. Lamar Blvd., Suite 400 Arlington, TX 76011-4125 NRC Senior Resident Inspector Waterford Steam Electric Station Unit 3 P.O. Box 822 Killona, LA 70066-0751 U. S. Nuclear Regulatory Commission Attn: Mr. N. Kalyanam Mail Stop O-07D1 Washington, DC 20555-0001 R.K. West, lerevents@inpo.org - INPO Records Center
Attachment to W3F1-2011-0028 Licensee Event Report 2011-001-00
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013 (10-2010)
, the NRC may sfor each block) not conduct or sponsor, and a person is not required to respond to, the digits/characters finformation collection.
PAGE Waterford 3 Steam Electric Station 05000 382 1OF 4
- 4. TITLE Waste Gas System Oxygen Exceeded Technical Specification Allowed Duration
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED FACILITY NAME DOCKET NUMBER MNHDAY YEAR YEA ISEQUENTIAL REV MONTH DAY YEAR N/ACLTNAEDKTUMR MONTH DAY'YEAR EAR NUMBER NO.
FACILITY NAME DOCKET NUMBER 02 16 2011 2011 1 I 0
04 16 2011 N/A 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 1 20.2201(b)
[] 20.2203(a)(3)(i)
E] 50.73(a)(2)(i)(C)
El 50.73(a)(2)(vii)
El 20.2201(d)
El 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A) fl 20.2203(a)(1)
El 20.2203(a)(4)
I] 50.73(a)(2)(ii)(B) 50,73(a)(2)(viii)(B)
_]
20.2203(a)(2)(i)
[
50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL El 20.2203(a)(2)(ii)
[= 50.36(c)(1)(ii)(A)
El 50.73(a)(2)(iv)(A)
El 50,73(a)(2)(x) 0% 20.2203(a)(2)(iii)
[
50.36(c)(2)
[]
50.73(a)(2)(v)(A) j]
73.71(a)(4) 100%
20.2203(a)(2)(iv)
[
50.46(a)(3)(ii)
[
50.73(a)(2)(v)(B)
[
73.71(a)(5) fl 20.2203(a)(2)(v)
[
50.73(a)(2)(i)(A)
[
50.73(a)(2)(v)(C)
E] OTHER El 20.2203(a)(2)(vi)
[
50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specify in Abstract below or in Actions taken to restore compliance per TS 3/4.11.2.5 Action 'a' included adding nitrogen directly to GDT C by bypassing the in-line nitrogen system regulators, aligning nitrogen to the Gas Surge Tank, and placing CDT C in service to receive the nitrogen.
On 2/18/11, at 10:47 p.m., GDT C was confirmed to be <2 percent oxygen concentration with >4 percent hydrogen concentration and TS 3/4.11.2.5 Action 'a' was exited.
CAUSAL FACTORS An apparent cause evaluation determined that the equalization among the GDTs was most likely due to seat leakage past GDT A nitrogen inlet valve NG-230A and inadvertent opening of GDT C nitrogen inlet valve NG-230C. Opening this valve created an equalizing flow path with GDTs A and C. Regarding detection of the event from 2/6/11 through 2/14/11, the Waste Gas Analyzer Panel was not aligned to GDT C because the normal practice is to only monitor the in-service CDT.
GDT C was not in service during this time period.
The initiating cause of the event is attributed to seat leakage on NG-230A and seat leakage/opening on NG-230C. This seat leakage is a result of corrosion product deposition on valve seats from high velocity flow through ball valves. The high velocity gases transport corrosion particles to~the valve seats resulting in seat damage, both from initial impact at high velocity and subsequent operation of the valve with corrosion particles embedded in the seats. The corrosion particles are the result of moisture in the gaseous waste management system that causes corrosion of carbon steel components such as piping, valves, and tanks.
Exceeding the 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> allowed outage time for TS 3/4.11.2.5 Action 'a' was contributed to by various issues. First, maintaining nitrogen gas directly to the GDT C using bypass features of the nitrogen system was pressure constricted to ensure the nitrogen system relief valve did not lift. Second, there were delays in aligning nitrogen gas directly to the GDT C using bypass features of the nitrogen system and in placing GDT C into service to add nitrogen via the CST. Third, GDT C inlet isolation valve GWM-206C [WEI was unable to be opened, which delayed adding nitrogen to GDT C via the CST.
CORRECTIVE ACTIONS
Completed actions include:
GDT C inlet valve GWM-206C has been rebuilt. A human performance evaluation was completed and determined that ineffective communication contributed to the delay. Applicable department personnel discussed interdepartmental communications and the need to ask for clarity when instruction provided is determined to be lacking or conditions have changed Planned actions include:
GDTs A and C nitrogen inlet valves are scheduled to be reworked. Corrective actions have been assigned to investigate the need for additional changes to address equipment issues contributing to this event.
SAFETY SIGNIFICANCE
There were no safety consequences as a result of this event. TS 3/4.11.2.5, Radioactive Effluents, Explosive Gas Mixture is provided to ensure that the concentration of potentially explosive gas mixtures contained in the Waste Gas Holdup system is maintained below the flammability limits of hydrogen and oxygen. Hydrogen gas is flammable at a concentration of 4 percent to 75 percent in air. During this event, concentrations of 4.9 percent oxygen and 19.7 percent hydrogen were present in GDT C based upon monitoring performed on 2/14/11. It is suspected that an out of specification mixture of oxygen and hydrogen may have been present when GDT C and GDT A pressures were equalized on 2/6/11, but its value is unknown. GDT C was returned to 2 percent oxygen concentration with greater than 4 percent hydrogen at 10:47 p.m. on 2/18/11. During this event GDT C contained a gas mixture that was potentially hazardous both from an industrial safety and radiological safety perspective. If there had been a catastrophic release of all of the GDT's contents to the environment, the total off site dose would have been -5.7E-1 curies. This is significantly less than the TS 3/4.11.2.6 LCO limit of 8.5E+4 curies for a single GDT.
SIMILAR EVENTS
There have been no previous similar licensee events reported in the last three years.
ADDITIONAL INFORMATION
Energy industry identification system (EIIS) codes are identified in the text within brackets [ I.