ML11243A062
| ML11243A062 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 06/28/2010 |
| From: | - No Known Affiliation |
| To: | Office of Information Services |
| References | |
| FOIA/PA-2011-0157 | |
| Download: ML11243A062 (7) | |
Text
Unit 2 System Status:.1i'
>T:*
User Status; 1P.TD
- Notification:
NN 200988413
==
Description:==
U2 Train A EDG Header Pressure Drop Created on: 06/28/2010 Reported By:
Responsible:
Priority:
Required Start: 06/2812010 13:59 End:
Order No:
Code:
Task Exists?
[Y]
Func.Loc.: S2.EDGS.2PI5958B G002 START 20 CYL RT BANK & 16 CYL LF BA Equipment:
Assembly:
Quality Class: II Location: DG Room: N/A Elevation: 030 Column: 0000 Planner Group: Maint I&C WorkCenter: MI Maint.
I&C / Rad Mon Plant: 1000 SONGS
- Services Reliability Classification: NON-CRITICAL ARC Review Status: A Awaiting review Feedback Req'd? H M Rule:
Sig Level:
Breakdown
[]
Malfunction Start:
Breakdown Duration:
H End:
==
Description:==
06/28/2010 13:59:51.(b)(6)
Phone (b)(6)
/ 1. Problem description
/ During the U2 Train A EDG surveillance on 6/28/2010 the isolated air start train header (feed from receiver tank T-335) appeared to have a significance pressure drop after the engine started.
The pressure was initially recorded at 188 psi and after engine started was down to 136 psi.
After the air start system was realigned the pressure increased back to ý195psi and maintained constant.
/
/ 2.
impact or consequence
/ During a normal monthly surveillance of the EDG one train of EDG air start is isolated at two locations.
The first location is at the air tank and the seccnd location is at the air start motors.
This leaves a residual amount of air between these two locations.
When the engine starts 4 solenoid valves open to engage and spin the air start motors and drive the fuel racks to full open until the engine reaches 150 rpm.
The air start sub system that is NOT isolated starts the engine, while the is-!a*led train onl-drives the fuel racks.
/
/ After further review of the system desian with one air tank isolated the Print Date: 06/29/2010 Page 1 of
Notification Continued Notification:
NN 200988413
==
Description:==
U2 Train A ED. HeDaer PLessure Drop Description Continued:
available volume of air start is reduced only to the header (piping) volume.
This is significantly less than the normal aligned available capacity (header volume and two air receivers).
Therefore, when the solenoid valves open on the isolated system the system pressure would reduce much more than on the un-isolated system due to the available system capacity.
/
/ This does not impact the ability of the EDG to perform its safety function because the EDG system is equipped with two redundant air start trains.
Both trains are 100% capable of cold cranking the EDG 5 times on a full charge.
Additionally, after the air receiver was re-aligned the pressure remained at >195psi.
/
/
- 3. Describe what happened
/ See Above
/
/ 4.
Immediate actions taken
/ Notified STA
/
/ 5.
Cause (if known)
/ See Above
/ 6.
Recommended Actions
/ After further review of this condition it does not appear to be a problem, however it would be prudent to monitor other EDGs to see if they experience the same condition during a normal monthly surveillance.
An N-SPT to engineering will address this monitor this condition.
/
Print Date: OG/29.!2010 Page 2 of 7 Print Date: 06/29/2010 Page 2 of "I
Task Summary Notification:
NN 200988413 Func.Loc.: S2.EDGS.2PI5JE5!B GO02 STAFT 20 C'L RT BANK & I6 CYL LF BA Location: DG Room: IT/A Elevation:030 Column: 0000 Sort No.:
0001 Code Group:14-TS-IOD Immediate Operability Determination Short Text: see long text Task Code: NO50 IOD-Canceled / Not Applicable/No DNC WorkCenter:
Responsible:
Sort No.:
0002 Code Group:N-SPT Short Text:
Task Code: ST01 WorkCenter: EMSYA Responsible: (b)(6)
General Support Record SPT CREATED Auxiliary Systems Print Date: 06,129/2010 Page 3 of 7 Print Date: 06,129/2C10 Page 3 of 7
Trending Worksheet Notification:
NN 200988413 Func.Loc.: S2.EDGS.2PIS-5qB (3002 START 20 CYL PT BANK & 15 CYL LF BA Part:
Damage:
Cause:
Activity:
Part:
Damage:
Cause:
Activity:
Part:
Damage:
Cause:
Activity:
Part:
Damage:
Cause:
Activity:
Print Date: 06,/29/2010 Pac:e 4 of 7
Task Details Notification:
NN 200988413 Func.Loc.: :
.ED3. FI935SB GOC2 START
,'CZL RT BANK & 16 CYL LF BA Location:
DG Room: 1,A Elevation:030 Column: 0000 Task D*lp l
-g Sort No.:
000i Code Group: N-TS-IOD Immediate Operability Determination Short Text: see long text Task Code: NO50 IOD-Canceled / Not Applicable/No DNC WorkCenter:
Responsible:
Status:
TSCO Planned Start: 06/28/2010 15:58 Planned End: 06/28/2010 15:58 Complete: 06/28/2010 15:58 Task Long Text:
NOTES:
- 1) Parts 1 through 4 will be completed by the STA.
- 2) Part 5 may be completed by Operations (STA) or Engineering (Responsible Engineer) when the SSC has been restored to a fully qualified status. IOD (Immediate Operability Determination)
This is an Immediate Operability Determination (IOD).
- 1. Deficiency Identified and the Affected Functional Location:
- 2. Identify the Specified Safety Function(s); include mission time (if applicable):
3.
Conclusion:
Determine OPERABLE/INOPERABLE Operable Inoperable Basis (provide discussion):
- 4. Extent of Condition Print Date: 06129/2010 Page -F of 7 Print Date: 0G,'29,'2010 Page 5 of
Task Details Continued Notification:
NN 200988413
==
Description:==
U2 Trrain A EDG Header Pressure Drc*
NOTE: Address the question: "Does the degraded ot nonconforming condition currentl%, exist on the other train/urit-"
a) Has an EOC Task been created to address the extent of condition (YES or NO)?
b)
If no EOC Task has been created, describe "other train/other unit" findings (if performed) or indicate N/A (if not necessary).
- 5.
IOD Closure Information Pressure drop was due to expansion of Air in the isolated header once solenoids opened. Air receivers were verified before and after starts to be able to hold and maintain pressure greater the 186 psig. During local vcrification of air pressures one header pressu.Le was tL 190 psig while the other was at 200 psig indicating no cross system leakage.
No degraded or non-conforming condition exists. !OD cancelled.
(b)(6)
,2
/20
/10o Print Date: 06/29..2101 Page 6 of 7
/
.t Task Details
',( )\\ (,%.
Notification:
NN Func.Loc.: S.EDGS. 2P1939538 Location: DG 200988413 G002.3TART 20 CYL RT BAIIK & IS CYL LF 2A Room: NiA Elevation:030 Column: 0000 TaAk nAtailn-Sort No.:
0002 Code Group: N-SPT G
Short Text:
Task Code: STO0 SPT WorkCenter:
EM SYA 2
Responsible: l(b)(6)
,-Status:
TSRL Planned Start:
Planned End: 08/21/2010 Complete:
eneral Support Record CREATED Auxiliary Systems Task Long Text:
SPT (General Support Record)
Describe the General support request:
Print Date:
0~5./29,'2ClO Po~e 7 of 7 Print Date: 06/29/2010 Page 7 of 7 i