Text

Part 21 Report - Electromatic Relief Valve (EMRV) Cutout Switch, Dresden, Units 2 and 3
	ML15280A387
Person / Time
Site:	Dresden
Issue date:	10/07/2015
From:	Thompson A; Exelon Corp
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	Download: ML15280A387 (4)
	v • d • e

10/07/2015 10/07/2015 U.S. Nuclear Regulatory Commission Operations Center Event Report P~

Panel Part 21 (PAR) Event# 51458 Rep Org: DRESDEN Notification Date!I Time: 10/06/2015 22:06 (EDT)

Supplier: GENERAL ELECTRIC HITACHI Event Date!/ Time: 10/05/2015 12:00 (CDT)

Last Modification: 10/06/20 15 Region: 3 Docket #:

City: MORRIS Agreement State: Yes County: License #:

State: IL NRC Notified by: AARON THOMPSON Notifications: ANN MARIE STONE R3DO HQ Ops Officer: JEFF HERRERA PART 21/50.55 REACTORS EMAIL Emergency Class: NON EMERGENCY 10 CFR Section:

21.21(d)(3)(i) DEFECTS AND NONCOMPLIANCE PART 21 REPORT - ELECTROMATIC RELIEF VALVE (EMRV) CUTOUT SWITCH "Following the return of the actuator that failed bench testing to GEH, on 6/12/15 at 1804 [CDT], General Electric Hitachi (GEH) notified Dresden Station of a potential parts quality Potential Failure of the EMRV Cutout Switch. It has been determined the notification is applicable to DNPS [Dresden Nuclear Power Station], Units 2 and 3.

"The GEH investigation concluded that the EMRV actuator assemblies failed to change state because of the failure of the cutout switch to fully close and provide the appropriate current path. Multiple contributing factors were discovered which could have led to the presence of the gaps in the cutout switch. The most significant of these factors is a change in lever arm positioning causing increased forces in the tension spring which prevent proper closure of the cutout switch. Design changes to reduce wear caused by vibration on the actuators changed lever arm position and also allowed for additional dimensional tolerance which tended to increase force in the tension spring.

"Identification of Facility and Component: DNPS / EMRV Actuator, GEH Part Number 352B2632G001 "Safety Significance (e.g., substantial hazard that is or could be created): Identified condition is a Potential Substantial Safety Hazard since it could cause affected EMRVs to fail to operate as designed, which could result in a loss of safety function. Potential to affect the Minimum Critical Power Ratio (MCPR), Reactor Coolant System (RCS), Automatic Depressurization System (ADS), and Low Set Relief Function "Plants with similar GEH cutout switches: Quad Cities Nuclear Power Station."

Part 21

Reference:

EN #51386

10/07/2015 U.S. Nuclear Regulatory Commission OperationsCenter Event Report Page 2 The licensee notified the NRC Resident Inspector.

NRC FORM 361 U.S. NUCLEAR REGULATORY COMMISSION (12-2000) OPERATIONS CENTER REACTOR PLANT EVENT NOTIFICATION WORKSHEET EN # 51458 NRC Operation Telephone Number: PRIMARY - 301-816-5100 or 800-532-3469", BACKUPS - [j1t] 301-951-0550 or 800-449-3694*

[2r*] 301-415-0550 and [3 rd 301-415-0553 *'Licensees who maintain their own ETS are provided these telephone numbers.

NOTIFICATION TIME FACILITY OR ORGANIZATION UNIT NAME OF CALLER CALL BACK #

2206 EDT Dresden 2/3 Aaron Thompson (815)942-0402 EVENT TIME & ZONE EVENT DATE POWER/MODE BEFORE POWER/MODE AFTER 97% ModelI - Unit 2 97% ModelI - Unit 2 1200 CDT 10/05/2015 100% Model1 - Unit 3 100% ModelI - Unit 3 EVENT CLASSIFICATIONS 1-Hr. Non-Emerglency I0CFR50.72(b)(1) EJ (v)(A) Safe S/D Capability AINA

-] GENERAL EMERGENCY GEN/AAEC [] TS Deviation ADEV El (v)(B) RHR Capability AINB

-] SITE AREA EMERGENCY SIT/AAEC 4-Hr. Non-emerglency I0CFR50.72(b)(2) L] j(v)(C) Control of Rad Release AINC

-1 ALERT ALE/AAEC [1 (i) TS Required S/D ASHU El (v)(D) Accident Mitigation AIND

-I UNUSUAL EVENT UNU/AAEC 17) (iv)IA) ECCS Dischargle to RCS ACCS [] (xii) Offsite Medical AMED

-I 50.72 NON-EMERGENCY (see next columns) [] (iv)(B) RPS Actuation (scram) ARPS El (xiii) Lost Comm/Asmt/Resp ACOM

-1 PHYSICAL SECURITY (73.71) DODD l[j (xi) Offsite Notification APRE 60-DAY Optionall0CFRE0.73(a)(1)

"J MATERIAL/EXPOSURE B??? 8-Hr. Non-emergency 10CFR50.72(b)(3) []l Invalid Specified System Actuation AINV

-I FITNESS FOR DUTY HFIT EIJ (ii)(A) Degraded Condition ADEG Other Unspecified Requirement (Identify)

SOTHER UNSPECIFIED REQMT. (see last column) 17) (ii)(B) Unanalyzed Condition AUNA [] 101CFR21.21 (d) 3)(i) Defect NONR

7) INFORMATION ONLY NNF [] (iv)IA) Specified System Actuation ASEF 0] NONR DESCRIPTION Include: Systems affected, actuations and their initiating signals, causes, effect of event on plant, actions taken or planned, etc. (continue on back)

PART 21 REPORT - ELECTROMATIC RELIEF VALVE CUTOUT SWITCH "This is a non-emergency notification from Dresden Nuclear Power Station (DNPS) required Under 10 CFR Part 21 concerning the design of Electromatic Relief Valve (EMRV) actuators Cutout Switches.

Following the return of the actuator that failed bench testing to GEH, on 6/12/15 at 18:04, General Electric Hitachi (GEH) notified Dresden Station of a potential parts quality Potential Failure of the EMRV Cutout Switch. It has been determined the notification is applicable to DNPS, Units 2 and 3.

The GEH investigation concluded that the EMRV actuator assemblies failed to change state because of the failure of the cutout switch to fully close and provide the appropriate current path. Multiple contributing factors were discovered which could have led to the presence of the gaps in the cutout switch. The most significant of these factors is a change in lever arm positioning causing increased forces in the tension spring which prevent proper closure of the cutout switch. Design changes to reduce wear caused by vibration on the actuators changed lever arm position and also allowed for additional dimensional tolerance which tended to increase force in the tension spring.

Identification of Facility and Component: DNPS / EMRV Actuator, GEH Part Number 352B2632G001 Identification of Component Manufacturer and/or Supplier: GE-Hitachi Nuclear Energy.

Nature of Defect: Cutout switch fails to close.

Safety Significance (e.g., substantial hazard that is or could be created): Identified condition is a Potential Substantial Safety Hazard since it could cause affected EMRVs to fail to operate as designed, which could result in a loss of safety function. Potential to affect the Minimum Critical Power Ratio (MCPR), Reactor Coolant System (RCS), Automatic Depressurization System (ADS), and Low Set Relief Function NOTIFICATIONS YES NO WILL BE ANYTHIING UNUSUAL OR L._.i YES (Explain above) I x NO NRC Resident x _______NOT UNDERSTOOD?

State~s) ___ X _____DID ALL SYSTEMS Lx YES I I. NO (Explain above)

Local ___ X _____FUNCTION AS REQUIRED?

IADDITIONAL Other Gov Agencies Media/Press Release

___ X x

MODE OF OPERATION UNTIL CORRECTED: Mode I FSTIMATFD

{Mv/D/)NATE IYs WN INFO ON BACK NRC FORM 361 (12-2000) PAGE 1 OF 2

NRC FORM 361 (12-2000) REACTOR PLANT EVENT NOTIFICATION WORKSHEET (CONTINUED)

ADDITIONAL INFORMATIONS DAI*If'.I f*lt"ZI/Al_ Dri: IrArra.:* PUEP~'*lf r*D ri 11.1i ADDI IIADE Ir ITrIZD I * ;f;,. rlTallvhaIeh~i,. a; l~lk...I.k~ p~u ir ;n aun lerrtr Release Rate (Cilsec) % T. S. Limit HOO Guide Total Activity (Ci) %T. S. Limit HOO Guide Noble Gas 0.1 Cilsec 1000 Ci Iodine ' "10 ijCilsec 0.01 Ci Particulate 1 pCi/sec mCi 1_____

Liquid (excluding tritium 10 giCi/min 0.1 Ci

& dissolved noble gas)

Liquid (tritium) 0.2 Cilmin __________5 Ci Total Activity,______

o lP~.o.o ansa, cnen ,r ,je~olains e~mneflsoBowdown Other ALARM SETPOINTS

%T. S. LIMIT if a licable*

RCS OR SG TUBE LEAKS: CHECK OR FILL INAPPLICABLE ITEMS: (specific details/explanations should be covered in the event description)

LOCATION OF LEAK (e.g., SG #. valve, pipe, etc.)

LEAK RATE UNITS: gpm/gpd T. S. LIMITS SUDDEN OR LONG TERM DEVELOPMENT LEAK START DATE TIME COOLANT ACTIVITY & UNITS PRIMARY /SECONDARY LIST OF SAFETY RELATED EQUIPMENT NOT OPERATIONAL EVENT DESCRIPTION (continued from front)

Date of Discovery of Initial Condition (taken from the IR): 06/12/15 Date of Discovery of the Substantial Safety Hazard (date of approval of the technical evaluation): 10105/15 Recommended Actions: Perform inspection at the next available opportunity to verify that proper over travel exists on the cutout switch and that the associated EMRV actuates properly.

"Number and Locations of All Defective Components: 1 - EMRV Unit 5 (SN 15433-5) was in Inventory.

"Any Advice Related to the Defect: Perform inspection at the next available opportunity to verify that positive over travel exists on the EMRV cutout switch.

"Contacts (Name, Title, Location, Phone Number, etc): Daniel Sipple, Sr Staff I&C Design Engineer, Dresden Nuclear Power Station, daniel .sippletexeloncorp.com, (815) 416-3631 "

The licensee notified the NRC Resident Inspector.

Plants with similar GEH cutout switches: Quad Cities Nuclear Power Station.

NRC FORM 361 (12-2000)PAE2O2 PAGE 2 OF 2