ML092510215
| ML092510215 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 09/03/2009 |
| From: | Stepantschenk P Engine Systems |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| EVENT 45326 | |
| Download: ML092510215 (11) | |
Text
0910312009 U.S. Nuclear Regulatory Commission OperationsCenter Event Report ea-elI General Information or Other (PAR) Event# 45326 Rep Org: ENGINE SYSTEMS, INC Notification Date / Time: 09/03/2009 16:12 (EDT)
Supplier: ENGINE SYSTEMS, INC Event Date / Time: 08/17/2009 (EDT)
Last Modification: 09/03/2009 Region: 1 Docket #:
City: ROCKY MOUNT Agreement State: Yes County: License #:
State: NC NRC Notified by: PAUL STEPANTSCHENK Notifications: DANIEL RICH R2DO HQ Ops Officer: ERIC SIMPSON PART 21 GROUP Emergency Class: NON EMERGENCY 10 CFR Section:
21.21 UNSPECIFIED PARAGRAPH PART 21 - FAULTY EMERGENCY DIESEL GENERATOR START-UP SOLENOID VALVE The following is excerpted from a fax received from the reporting organization:
Engine Systems Inc. (ESI) began a 10CFR21 deviation evaluation on 08/17/09 after Brunswick Nuclear Plant (BNP) notified ESI of a failure of one of their air start solenoid valves. The valve failure reportedly occurred on 08/02/09 as indicated by a slow start of the safety-related emergency diesel generator during a surveillance run.
This caused the diesel generator to be declared inoperable. Subsequently, ESI opened up an internal work order to receive back the failed valve (S/N 1230588) as well as two more valves believed to be suspect (S/Ns 1230583 and 1230586). Soon after, another internal work order was opened up to receive and evaluate 10 additional air start solenoid valves from BNP inventory. ESI completed the evaluation on 8/31/09 and determined the issue to be reportable in accordance with 10 CFR 21, "Reporting of Defects and Non-compliance."
The solenoid actuated valve in question opens when energized and closes when de-energized. The valve is installed in-line with the starting air piping via 2" NPT connections in the valve body and is utilized for two applications on the Nordberg diesel engine. Upon receipt of a diesel generator start signal, the valve is energized and directs the starting air supply to either the starting air header of the diesel engine or turbocharger jet assist piping. Failure of the valve in these applications could result in a failure of the diesel engine to start and therefore prevent the diesel generator from performing its safety-related function. A total quantity of four valves are used per engine; one installed in the left bank starting air piping, one in the right bank starting air piping, and two in parallel supplying the turbocharger jet assist.
ESI's investigation determined that in failed valves, the upper DC sleeve had dislodges from the solenoid housing and slides down the bonnet, contacting the lower DC sleeve. This action disrupts the magnetic field to the extent that the valve will not function properly.
09/03/2009 U.S. NuclearRegulatory Commission OperationsCenter Event Report Page 2 General Information or Other (PAR) Event # 45326 ESI has supplied a total quantity of 33 the affected solenoid valves and all were supplied to BNP. There are only two utilities that use Nordberg diesel engines for safety-related power supply and BNP is the only nuclear site ESI is aware of that uses the affected valve.
09-03--09;03:44PM; ;2S2-446-3830 # 2/ 10 ENGINE SYSTEMS, INC.
175 Freight Road, Rocky Mount, NC 27804 Telephone: 252t977-2720 (E1 Fax: 2521446-1134 Report No. 10CFR21-0096 Rev. 0: 09/02/09 10CFR21 REPORTING OF DEFECTS AND NON-COMPLIANCE COMPONENT: Air Start Solenoid Valve Nordberg P/N 1698 760
- Magnatrol P/N 42A57AHT SYSTEM: Emergency Diesel Generator - air starting system CONCLUSION: Reportable in accordance with 1 OCFR21 Prepared By: Date: 9/ 3 /0?
Engineering Manager Reviewed By: Date: 2 j/AViy Quality Assurance Manager Quality Performance With Pride
09-03-09;03:44PM; ;252-446-3830 # 3/ 10 Report No. 10CFR21-0096 Record of Revisions Page: 1 of 1 REV DATE PAGE DESCRIPTION 0 09/02/09 Initial issue.
09-03-09;03:44PM; 0~-3-0;0:44M;;252-446-3630 # 4/ 10 Report No. 10CFR21-0096 Revision: 0 Date: 09/02/09 Page: 1 of 7 COMPONENT:
Diesel engine air start solenoid valve, Nordberg P/N 1698 760 (Magnatrol P/N 42A57AHT)
DISCUSSION:
Engine Systems Inc. (ESI) began a 10CFR21 deviation evaluation on 08/17/09 after Brunswick Nuclear Plant (BNP) notified ESI of a failure of one of their air start solenoid valves. The valve failure reportedly occurred on 08/02/09 as indicated by a slow start of the safety-related emergency diesel generator during a surveillance run. This caused DG2 to be declared inoperable. Subsequently, ESI opened up an internal work order to receive back the failed valve (S/N 1230588) as well as two more valves believed to be suspect (S/Ns 1230583 and 1230586).
Soon after, another internal work order was opened up to receive and evaluate 10 additional air start solenoid valves from BNP inventory. ESI completed an evaluation on 8/31/09 that determined the issue to be reportable in accordance with 10CFR-part 21, "Reporting of Defects and Non-compliance".
Magnatrol P/N 42A57AHT is a solenoid actuated valve which opens when energized and closes when de-energized. The valve is installed in-line with the starting air piping via 2" NPT connections in the valve body and is utilized for two applications on the Nordberg diesel engine. Upon receipt of a diesel generator start signal, the valve is energized and directs the starting air supply to either the starting air header of the diesel engine or turbocharger jet assist piping. Failure of the valve in these applications could result in a failure of the diesel engine to start and therefore prevent the diesel generator from performing its safety-related function. A total quantity of four valves are used per engine; one installed in the left bank starting air piping, one in the right bank starting air piping, and two in parallel supplying the turbocharger jet assist.
Internally, the valve uses a solenoid coil to produce the required magnetic field to lift a plunger which in turn lifts a pilot valve and piston assembly. The action of these components opens the valve and allows air flow from the inlet to the outlet of the valve. Without the magnetic field produced by the coil, the valve would not actuate properly. Figures 1, 2, and 3 on the following page illustrate the overall appearance of the S/N 1230588 valve assembly and show the internals of the solenoid housing.
Installed within the solenoid housing is the encapsulated solenoid coil (which is retained by a 3-wave spring washer) as well as an upper DC sleeve and lower DC sleeve. These items all surround a stationary bonnet which encases the plunger. The upper and lower DC sleeves direct the magnetic field to the proper location within the valve to move the plunger/piston assembly. Without the sleeves, the magnetic field would be altered and the valve would not open.
09--03--09;03:44PM; ;252-446-3830 # 5/ 10 Report No. 10CFR21-0096 Revision: 0 Date: 09/02/09 Page: 2 of 7 I Figure 2: Dislodged Sleeve I I Figure 1: Overall Valve Assembly 1 Figure 3: Correct Sleeve Location ESI's investigation determined that in the failed valve, the upper DC sleeve had dislodged from the solenoid housing and slid down the bonnet, contacting the lower DC sleeve. This action disrupted.
the magnetic field to the extent that the valve would not function properly. Figure 2 depicts the upper DC sleeve missing from the housing and located inside the coil, resting against the lower DC sleeve. This figure also illustrates the condition of failed valve S/N 1230588 when the solenoid housing was first removed. Figure 3 shows a disassembled valve in which the upper DC sleeve is installed in its proper location (note that a slight interference between the wave washer I.D. and sleeve O.D. keeps the washer in the housing).
09-03-09;03:44PM; ;252-446-3830 # 6/ 10 Report No. 10CFR21-0096 Revision: 0 Date: 09/02/09 Page: 3 of7 Im ! i q I Upper DC sleeve contacting I tower DC sleeve I Upper DC sleeve is still retained in solenoid housing, only lower DC U! sleeve on bonnet F
Figure 4: Actual Condition with Figure 5: Expected Condition Housing Removed with Housing Removed I
I Figure 4 shows the condition of valve S/N 1230588 when the solenoid housing and coil were first removed. As shown above, the upper DC sleeve is not in the solenoid housing but has slid down the bonnet and contacted the lower DC sleeve. Figure 5 illustrates how the valve should have looked with the solenoid housing and coil removed.
Aside from the valve that failed at the customer's site, the two other valves S/Ns 1230583 and 1230586 were inspected. Though the upper DC sleeve remained installed in the solenoid housing, the sleeve of S/N 1230586 displayed a slight amount of wiggle when actuated by hand. Based on correspondence with the manufacturer, this may not ultimately result in failure but is unacceptable none the less. The sleeve of S/N 1230583 did not have any wiggle. ESI also inspected a previous seismic specimen valve, S/N 1238281, for the same condition. The seismic specimen valve was also able to be wiggled by hand and was actually able to be removed from the housing by hand by working the sleeve back and forth.
During that time, BNP also returned 10 more solenoid valves on ESI IWO 8001479. All of the valves were tested and functioned properly; however ESI's disassembly inspection revealed that of the 10, qty six had sleeves that were loose. The serial numbers of the returned valves are listed in Table 1 on the following page.
09-03--09;03:44PM; ;252-446-3830 # 7/ 10 Report No. 10CFR21-0096 Revision: 0 Date: 09/02/09 Page: 4 of 7 AFFECTED USERS:
ESI has supplied a total of qty. 33 of these Nordberg P/N 1698 760 (Magnatrol P/N 42A57AHT) solenoid valves and all of the valves were supplied to Brunswick Nuclear Plant. There are only two utilities that use Nordberg diesel engines for safety-related power supply and BNP is the only nuclear site ESI is aware of that uses the Magnatrol valve (Duke-McGuire does not). ESI supplied the valves on two separate jobs (corresponding to two BNP purchase orders). The list of solenoid valve serial numbers supplied is provided in Table 1 below:
ESI S.O. ES! C-of-C Date oty Customer Customer Valve SINs ESI P.O.
P.O.
1225127 1225140 10/19/07 6 1225133 81163 1225137 1225139 1225132 00333377 12305831 3003544 1230584 1230585 03/20/08 8 1230586' 82625 1230587 1230588' 1230589 1230590 1238271 Progress Energy - 1238272 Brunswick Nuclear Plant 12382732 1238274 12382752 1238276 12382772 1238278 12382792 3004173 05/05/08 19 00358798 1238280 84601 1238282 12382832 12382842 1238285 1238286 12382872 12382882 12382892 12382902 Table 1: Listing of Nuclear Safety Related Air Start Solenoid Valves Shipped with Suspect DC Sleeves Installed Notes:
1: These three valves were returnedto ES! on IWO 8001478.
2: These 10 valves were returnedto ESI on IWO 8001479.
09--03-09;03:44PM; ;262-446-3830 # 8/ 10 Report No. 10CFR21-0096 Revision: 0 Date: 09/02/09 Page: 5 of 7 CORRECTIVE ACTION:
- 1. The 13 solenoid valves returned by BNP will be reworked at ESI by replacing the solenoid housing on each of the valves with a new, dedicated housing.
- 2. ESI has added verification of proper DC sleeve assembly to the critical characteristic inspection activity for future air start solenoid valve shipments.
- 3. The remaining solenoid valves at BNP should be inspected and reworked as necessary with dedicated, replacement solenoid housings. The recommended inspection and rework procedure is listed below.
INSPECTION / REWORK PROCEDURE:
The below steps are provided to give the customer guidance on how to inspect valves that are already installed in the starting air piping as well as valves which may be in inventory. Since the procedure does not require disturbing the pressure boundary of the installed system, it is much more advantageous for the customer to perform this inspection on-site with the valve installed rather than remove the valve from the piping system.
- 1. If installed in a piping system, disconnect power to the valve.
- 2. Identify the solenoid housing and associated hardware (qty 4, 3/8-16 capscrews).
Reference Figure 6 below. Remove the capscrews and housing.
u Figure 6: View of Air Start Solenoid Assembly I
09-03--09;03:44PM; ;252-446-3830 # 9/ 10 Report No. 10CFR21-0096 Revision: 0 Date: 09/02/09 Page: 6 of 7
- 3. Once removed, the interior of the solenoid housing should resemble Figure 7 below. Note that the upper DC sleeve and wave washer are still installed in the housing.
DC sleeve and wave SN 3washer installed Figure 7: View Inside of I Solenoid Housing
- 4. There are two inspection criteria that must be satisfied to verify acceptable installation of the upper DC sleeve. These two criteria are:
a) No movement or "wiggle" of the upper DC sleeve is allowed. This inspection is performed by grabbing the housing with both hands and placing both thumbs inside the sleeve and attempting to rock the sleeve back and forth. Then rotate the housing 90* and repeat the inspection. The sleeve shall be staked in firm with no movement allowed in either direction. Any movement is cause for rejection.
b) The upper DC sleeve shall be staked to the solenoid housing in four locations. The presence of staking shall be visually apparent (see Figure 9). The absence of four visual stake marks at the interface of the sleeve and housing is cause for rejection.
Followinq Step 4. perform one of the following actions:
5a. If both of the above referenced criteria are met, re-install the solenoid housing. Verify the wave washer is present. Torque the four 3/8-16 capscrews to 24'ft-lbs.
5b. If the DC sleeve is found loose in the housing or staking is missing, replace with a new, dedicated housing provided by ESI. Note that the wave washer must be reused and the nameplate from the original solenoid housing must be removed and installed on the replacement housing. The nameplate is affixed via two self-tapping screws which must also be reused. Tighten the self-tapping screws hand tight (snug) until fully seated.
Torque the housing's four 3/8-16 capscrews to 24 ft-lbs.
09-03--09;03:44PM; ;252-446-3830 # 10/ 10 Report No. 10CFR21-0096 Revision: 0 Date: 09/02/09 Page: 7 of 7 5c. If the DC sleeve has dislodged and is missing from the housing, remove the coil from the assembly to expose the sleeve (see Figure 8). Remove the upper DC sleeve and re-install the coil. The coil will fit loosely around the bonnet and the wire leads should be fed through the conduit opening. Then replace with a new, dedicated housing provided by ESI. Note that the wave washer must be reused and the nameplate from the original solenoid housing must be removed and installed on the replacement housing. The nameplate is affixed via self-tapping screws which must also be reused. Tighten the self-tapping screws hand tight (snug) until fully seated. Torque the housing's four 3/8-16 capscrews to 24 ft-lbs.
Upper DC sleeve contacting lower DC sleeve Figure 8: View Showing Upper DC Sleeve Contacting Lower DC Sleeve I
Note: If replacingthe solenoid housing, the customer may notice that there has been a process change for the DC sleeve.
Whereas the valves supplied by ESI have a black painted sleeve, in mid-to-late 2008 the manufacturerdeleted the painting process and switched to zinc plating. According the manufacturer,this is the only process change that has taken place as far as records Indicate.
Upper DC sleeve Iszinc plated I on replacement housing.
Figure 9: Replacement Housing With Zinc Plated Sleeve 4
Visual indication of staking (shown in two places)
- 6. Upon completion of these steps, the air start solenoid valve is suitable for continued use on the Nordberg emergency diesel generator set.