05000244/LER-2018-001, R.E. Gina Nuclear Power Plant Regarding Leakage in Reactor Coolant System Pressure Boundary Through an Existing Weld in Original Installation Equipment Due to Orifice Wear/Erosion Resulting in Progressively Increasing System

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R.E. Gina Nuclear Power Plant Regarding Leakage in Reactor Coolant System Pressure Boundary Through an Existing Weld in Original Installation Equipment Due to Orifice Wear/Erosion Resulting in Progressively Increasing System .
ML18086A032
Person / Time
Site: Ginna Constellation icon.png
Issue date: 03/23/2018
From: Swift P
Exelon Generation Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
LER 2018-001-00
Download: ML18086A032 (6)
v • d • e


LER-2018-001, R.E. Gina Nuclear Power Plant Regarding Leakage in Reactor Coolant System Pressure Boundary Through an Existing Weld in Original Installation Equipment Due to Orifice Wear/Erosion Resulting in Progressively Increasing System .
Event date:
Report date:
Reporting criterion: 10 CFR 50.73(a)(2)(ix)(A)
10 CFR 50.73(a)(2)(iv)(A), System Actuation
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)
2442018001R00 - NRC Website
v • d • e

text

Exelon Generation March 23, 2018 U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTENTION: Document Control Desk

SUBJECT:

RE. Ginna Nuclear Power Plant Renewed Facility Operating License No. DPR-18 Docket No. 50-244 Paul Swift Plant Manager R.E. Ginna Nuclear Power Plant 1503 Lake Rd.

Ontario, NY 14519 315-791-5205 Office www.exeloncorp.com paul.swift@exeloncorp.com LER 2018-001, Leakage in Reactor Coolant System Pressure Boundary through an existing weld in original installation equipment due to orifice wear/erosion resulting in progressively increasing system vibrations.

The attached Licensee Event Report (LER) 2018-001 is submitted under the provisions of NUREG-1022, Event Reporting Guidelines. There are no new commitments contained in this submittal. This submittal is for revision O of the LER.

Should you have any questions regarding this submittal, please contact Kyle Garnish at 315-791-5321.

Sincerely,

~~lM~

Paul Swift, Ginna Plant Manager PS/ces

Attachment:

LER 2018-001 cc:

NRC Regional Administrator, Region I NRC Project Manager, Ginna NRC Resident Inspector, Ginna

Attachment LER 2018-001

NRCFORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 03/31/2020 (02-2018)

Estima1ed, the NRC may not conduct or sponsor, and a person is not required to respond to, the infonnation collection.

3.Page R. E. Ginna Nuclear Power Plant 05000244 1

OF 4

4. Title Leakage in Reactor Coolant System Pressure Boundary through an existing weld in original installation equipment due to orifice wear/erosion resulting in progressively increasing system vibrations.
5. Event Date
6. LER Number
7. Report Date
8. Other Facilities Involved I

Sequential I Rev Facility Name Docket Number Month Day Year Year Number No.

Month Day Year 05000 Facility Name Docket Number 01 23 2018 2018 -

001 00 03 23 2018 05000

9. Operating Mode
11. This Report is Submitted Pursuant to the Requirements of 10 CFR §: (Check all that apply)

D 20.2201(b)

D 20.2203(a)(3)(i)

~ 50. 73(a)(2)(ii)(A)

D 50. 73(a)(2)(viii)(A)

D 20.2201(d)

D 20.2203(a)(3)(ii)

D 50. 73(a)(2)(ii)(B)

D 50. 73(a)(2)(viii)(B) 1 D

D 20.2203(a)(1)

D 20.2203(a)(4)

D 50. 73(a)(2)(iii) 50.73(a)(2)(ix)(A)

D 20.2203(a)(2)(i)

D 50.36(c)(1 )(i)(A)

D 50.73(a)(2)(iv)(A)

D 50. 73(a)(2)(x)

10. Power Level D 20.2203(a)(2)(ii)

D 50.36(c)(1 )(ii)(A)

D 50. 73(a)(2)(v)(A)

D 73.71 (a)(4)

D 20.2203(a)(2)(iii)

D 50.36(c)(2)

D 50. 73(a)(2)(v)(B)

D 73. 71 (a)(5)

D 20.2203(a)(2)(iv)

D 50.46(a)(3)(ii)

D 50. 73(a)(2)(v)(C)

D 73. 77(a)(1) 100 D 20.2203(a)(2)(v)

D 50.73(a)(2)(i)(A)

D 50.73(a)(2)(v)(D)

D 73. 77(a)(2)(ii)

D 20.2203(a)(2)(vi)

~ 50. 73(a)(2)(i)(B)

D 50. 73(a)(2)(vii)

D 73.77(a)(2)(iii)

D 50.73(a)(2)(i)(C)

D Other (Specify in Abstract below or in

D. OTHER SYSTEMS OR SECONDARY FUNCTIONS AFFECTED

None

E. METHOD OF DISCOVERY

YEAR 2018 SEQUENTIAL NUMBER 001 REV NO.

00 Routine trending of RCS Operational leakage determined that unidentified leakage had increased. The subsequent inspection during containment entry verified the system and that it was RCS pressure boundary leakage.

F. SAFETY SYSTEM RESPONSES:

No safety systems actuated, which was expected response.

Ill. CAUSE OF EVENT:

In the absence of a preserved flaw, a definitive cause for the failure cannot be provided and a most-probable cause was assessed during engineering causal analysis. The most probable cause of the leak is orifice wear/erosion resulting in progressively increasing system vibrations.

IV.ASSESSMENT OF THE SAFETY CONSEQUENCES OF THE EVENT:

Pressure boundary leakage is defined as leakage (except primary to secondary leakage) through a nonisolable fault in an RCS component body, pipe wall, or vessel wall. TS LCO 3.4.13, Action 8.1, requires the plant to be shutdown and taken to Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and Mode 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> if any RCS pressure boundary leakage exists. This action is based on reducing the severity of the leak and preventing the leak itself from causing further deterioration of the pressure boundary. During the event described in this report, the pressure boundary leak was isolated, preventing any further deterioration and securing the actual pressure boundary leakage, within approximately 82 minutes of discovery which is well before the six hour requirement for plant shutdown.

Based on the above considerations, this event is not considered to have had any significant effect on the health and safety of the public.

V. CORRECTIVE ACTIONS

A ACTION TAKEN TO RETURN AFFECTED SYSTEMS TO PRE-EVENT NORMAL STATUS:

Weld joint was removed and re-welded to code standard. The weld repair was successful and a post-repair PT examination identified no indications. PMT included a VT-2 inspection and identified no leakage at normal operating pressure and temperature. Following repair completion, the system was realigned to Normal Letdown and Excess Letdown removed from service.

B. ACTION TAKEN OR PLANNED TO PREVENT RECURRENCE:

Performed Extent of Condition VT-2 Examinations on similar welds in containment.

Replace LCH01 (AOV-200A flow orifice) during 2018 refueling outage.

Evaluate vibration data and determine methodology for monitoring orifice degradation.

Evaluate similar orifices for susceptibility to Cavitation Erosion.

3. LER NUMBER SEQUENTIAL NUMBER 001 Switched to LCH02 (AOV-200B flow orifice) as the preferred orifice for the remainder of the cycle.

VI.ADDITIONAL INFORMATION:

None A FAILED COMPONENTS:

Piping weld in eves system B. PREVIOUS LERs ON SIMILAR EVENTS:

A search of all Ginna LERs submitted to the NRC determined there have been no prior LERs reporting RCS pressure boundary leakage.

C. THE ENERGY INDUSTRY IDENTIFICATION SYSTEM (EIIS) COMPONENT FUNCTION IDENTIFIER AND SYSTEM NAME OF EACH COMPONENT OR SYSTEM REFERRED TO IN THIS LER:

COMPONENT-Pipe Fitting IEEE 803 FUNCTION NUMBER - PSF IEEE 805 SYSTEM IDENTIFICATION - SB REV NO.

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