ML110210121
| ML110210121 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 01/19/2011 |
| From: | Todd R - No Known Affiliation |
| To: | Office of Nuclear Reactor Regulation, NRC/RGN-II |
| References | |
| 46554 | |
| Download: ML110210121 (6) | |
Text
0111912011 U.S. Nuclear Regulatory Comnmission Operations Center Event Report Page I Power Reactor Event#
46554 Site: OCONEE Notification Date /Time: 01/19/2011 17:44 (EST)
Unit:
3 Region: 2 State: SC Event Date/ Time: 01/06/2011 17:02 (EST)
Reactor Type: [1] B&W-L-LP,[2] B&W-L-LP,[3] B&W-L-LP Last Modification: 01/19/2011 Containment Type: DRY AMB DRY AMB DRY AMB NRC Notified by: RANDY TODD Notifications: MARVIN SYKES R2DO HQ Ops Officer: JOE O'HARA PART 21 GRP EMAIL Emergency Class: NON EMERGENCY 10 CFR Section:
21.21 UNSPECIFIED PARAGRAPH Unit Scram Code RX Critlnit Power initial RX Mode Curr Power Current RX Mode 3
N Yes 100 Power Operation 100 Power Operation FOREIGN MATERIAL FOUND IN SPARE HEAT EXCHANGER "Part 21 reportable defect foreign material (FM) was discovered in a spare heat exchanger (HX) when visually inspected on 10/19/10 as part of contingency planning for potential installation of the HX during the 3EOC.25 refueling outage.
Visual inspections with a video probe (fiberscope) were being performed on the inlet/outlet channels and the tubes of a spare HX to verify that no FM was present. However, when performing these inspections, a problem was encountered in that maintenance was unable to disassemble and remove the bonnet from the lower (inlet)
.pressure seal connector on the HX.
"Subsequently, on 10/19/10 a fiberscope inspection was performed of the "back side" of the pressure seal bonnet by inserting a fiberscope thru the inlet nozzle access. A foreign object that appeared as a u-shaped piece of thin wire was seen just behind the pressure seal bonnet, laying in the bottom of the body. Due to the inability to disassemble the pressure seal connector, the affected HX was not installed, "The FM was retrieved from the spare HX on December 27,2010 and its size and material type confirmed. The "U-shaped" material is type 304 stainless steel and appears to be a metal shaving. It is about 1-1/2" in length if the "u" was stretched out, 3/32" wide and less than 1/64" thick.
"The HX was intended for use as a Reactor Coolant System Letdown Cooler. It was ordered in 2006 and was supplied by Energy Steel Supply Company (ESSC), Catalog 10 350952, SIN N32389-1, Purchase Order No. DP 19279.
"Initial Safety Significance: This event has no actual significance since the issue was discovered prior to installation
01/19/2011 U.S. Nuclear Regulatory Commission Operations Center Event Report Page Power Reactor Event#
46554 of the component and the component was not installed. However, Part 21 requires evaluation based on the assumption that the component was installed in the as-found condition. On 1/6/2011, Oconee Engineering concluded that, in some low probability scenarios, this FM could constitute a Substantial safety hazard. Per the postulated scenarios, the FM would be flushed out of the cooler when placed in service. A low potential exists that the FM could be trapped in a downstream valve and damage the seat, resulting in leakage. The cooler outlet valve and the next valve in series are containment isolation valves. If the FM caused leakage in one of those valves and the other was affected by a postulated single failure, any resultant leakage would constitute containment leakage.
Also, in some event scenarios, unacceptable leakage.past the cooler outlet valve seat could render the Oconee Standby Shutdown Facility (SSF) Reactor Coolant Make-up System inoperable. Therefore, Oconee concludes this issue meets the Part 21 definition as a reportable defect.
"Corrective Action(s): The affected spare cooler was not installed. Subsequently, the FM was removed. A second spare cooler was inspected, no similar FM was found, and the second cooler was installed."
The NRC Resident Inspector will be notified.
0 1/ 19 / 11 17: 41 FAX
-4 NRC 0l001 Attachment B NRC Event Notification Worksheet OMP 1-14 Page 1 of 4 NRC Event Notification Worksheet Notification Time Facility or Organization Unit Caller's Name Call Back #
Oconee Nuclear 3
ENS 256-9931 Station R"4/y 7;2 (864) 873-3271 NRC Operations Officer Contacted:
NRC Event Number:
Event Time/Zone I
Event Date Power/Mode Before I
Power/Mode After 17:02.! EST 1/6/2011 100%/Mode 1 100%/Mode 1 I
Event Classifications Li 1]
LI LI General Emergency Site Area Emergency Alert 8-Hour Non-Emergency 10 CFR 50.72 (b) (3)
Li (ii) (A) Degraded Condition Li (ii) (B) Unanalyzed Condition El (xiii) Loss of emergency assessment capability/offsite communications El (iv) (A) System Actuation Li RPS
[L Unusual Event EL 50,72 Non-emergency (see other columns)
Li 72.75 Spent Fuel (ISFSI)
Li 73.71 Physical Security El Transportation El 20 2202 Material/Exposure
[L 26.73 Fitness for Duty 0
Other-21.21(d)(3)(i) Initial Notification 1-Hour Non-emergency 10 CFR 50.72 (b)(1)
Li Deviation from TS per 50.54(x)
I 4-Hour Non-Emergency 10 CFR 50.72 (b)(2)
Fi (i) TS Required Shutdown Li (iv) (A) ECCS Discharge into RCS Li (iv) (B) RPS Actuation (while critical)
EL (xi) News release/notification to other government agencies Li E]
El Li Li EL Containment isolation Li ECCS Li EFW Li Containment spray/coolers Li Emergency AC (Keowee Hydro)
(v) (A) Safe Shutdown Capability (v) (B) Residual Heat Removal Capability (v) (C) Control of radiological material (v) (D) Accident Mitigation (xii) Transport contaminated person to offsite medical facility
() 1 / 19/11 17:42 FAX 11 NRC -I0O2 Attachment B OMP 1-14 NRC Event Notification Worksheet Parre 2 of 4 Event Description (Include systems affected, actuations and their initiating signals, causes, effect of event on plant, actions taken or planned, etc.)
Event Part 21 reportable Defect Foreign material (FM) was discovered in a spare heat exchanger (HX) when visually inspected on 10/19/10 as part of contingency planning for potential installation of the HX during the 3EOC-25 refueling outage.
Visual inspections with a videoprobe (fiberscope) were being performed on the inlet/outet channels and the tubes of a spare HX to verify that no FM was present. However, when performing these inspections, a problem was encountered in that Maintenance was unable to disassemble and remove the bonnet from the lower (inlet) pressure seal connector on the HX.
Subsequently, on 10/19/10 a fiberscope inspection was performed of the "back side" of the pressure seal bonnet by inserting a fiberscope thru the inlet nozzle access. A foreign object that appeared as a u-shaped piece of thin wire was seen just behind the pressure seal bonnet, laying in the bottom of the body.
Due to the inability to disassemble the pressure seal connector, the affected HX was not installed.
The FM was retrieved from the spare HX on December 27, 2010 and its size and material type confirmed.
The "U-shaped" material is type 304 stainless steel and appears to be a metal shaving.
It is about 1-1/2" in length if the "U" was stretched out, 3/32" wide andless than 1164" thick, The HX was intended for use as a Reactor Coolant System Letdown Cooler. It was ordered, in 2006 and was supplied by Energy Steel Supply Company (ESSC), Catalog ID 350952, SIN N32389-1, Purchase Order No. DP 19279.
Initial Safety Significance:
This event has no actual significance since the issue was discovered prior to installation of the component and the component was not installed. However, Part 21 requires evaluation based on the assumption that the component was installed in the as-found condition. On 1/612011, Oconee Engineerng concluded that, in some low probability scenarios, this FM could constitute a substantial safety hazard. Per the postulated scenarios, the FM would be flushed out of the cooler when placed in service. A low potential exists that the FM could be trapped in a downstream valve and damage the seat, resulting in leakage-The cooler outlet valve and the next valve in series are containment isolation valves. If the FM caused leakage in one of those valves and.the otherwas affected bya postulated single failure, any resultant leakage would constitute containment leakage. Also, in some event scenarios, unacceptable leakage past the cooler outlet valve seat could render the Oconee Standby ShutdownFacility (SSF) Reactor Coolant Make-up System inoperable. Therefore, Oconee concludes this issue meets the Part 21 definition as a reportable defect.
Corrective Action(s):
The affected spare cooler was not installed. Subsequently, the FM was removed, A second spare cooler was inspected, no similar FM was found, and the second cooler was installed.
Anything unusual or not understood?
0-Yes (Explain above)
J No Did all systems function as required?
E Yes LI No (Explain above)
Mode of operations until corrected:-
JEstimated restart date:
Does event result in a radiological release, RCS leak, or steamblI Yes (complete pageI bNo generator tube leak?
7 4)
Does the event result in any of the units EI Yes (complete Oconee Plant Status Z
No experiencing a transient?
I sheet)
01/19/11 17:42 FAX 1-i NRC
[a]003 Attachment B NRC Event Notification Workshect OMP 1-14 Page 3 of 4 Notifications NRC Resident tY/NXIl 'bt Plant Manager:
Notified By:
Time:
Notified By:
Time:
State(s):
Y'*qwill be Operations Superintend'ent:
Y/N,61b*'
Notified By:
Time:
Notified By:
Time:
Local:
Yo~ill be Other Government Agencies:
ylwill be Notified By:
Time:
jNotified By:
-ime:
Media/Press Release:
Y(5WIl be lOther:ilb Notified By:
Time iNotified By Time ratConos ifi Manatn er/Emergenc Coordinator Approval:
Date/Time:.
S N Re Notification Compl&e"*by Caller, NRC Communi'cator,-
Date/Tme:
ol.i19/11 17:42 FAX 4 NRC Z004 Attachment B NRC Event Notification Worksheet OMP 1-14 Page 4 of 4 Additional Information for Radiological Releases Radiolooical Release (check as aDDlicable with siecific details in event description including" release path)
/
E L qiuid Release
-[]Gaseous Release 10 Unplanned Release Planned Release Monitored El Unmonitored F] Off-Site Release I I TS Exceeded El Personnel El-Rad Mon Alarms Ei Off-Site Protected Actions Li Terminated Exposed or Recommended Contaminated C n Areas Evacuated -
L OnggkfI Release
% TS Limit HOO Guide Total Activi S Limit HOO Guide Rate (Ci/sec)
Noble gas:
0.1 Csec 1000 Ci Iodine:
uCi/secO/
0.01 Ci Particulate:
I RFTI01 Ci Liquid (excluding tritium and 1
0.1 Ci dissolved noble gases):
Liquid (tritium):
\\,/ O.'2 Citmin 5 Ci Total Activity:
,jig___
Plant Stack iondenser/Air Main Steam SG Blowdown Other
_Ejector Line Rad Monitor Readings:
_/_
Alarm Setpoints:
% TS Limit (if applicable):
Additional lnformn'on for Reactor Coolant Leaks and Steam Generator Tube Leaks Location of the leak (e.g. r Iave, pipe, etc.)
Leak Rate:
/
Units (gpm/gpd):
TS Limit-.
Sudden or Long Term
/
Development Leak Start Date:
Time:
Coolant Activity & Units:
Primary -
Secondary -
List of Sa Related Equipment Not Operational: