ML103140214

Lr - Regional Inspection Spreadsheet

ML103140214
Person / Time
Site:	Diablo Canyon
Issue date:	11/01/2010
From:	- No Known Affiliation
To:	Division of License Renewal
References
Download: ML103140214 (7)

Text

DiabloCanyonNPEm Resource From: Tan, Miranda [M1TF@pge.com]

Sent: Monday, November 01, 2010 12:07 PM To: Pick, Greg Cc: Grebel, Terence

Subject:

RE: Regional Inspection Spreadsheet Attachments: deg jw pp U1.pdf; RESPONSE TO NRC QUESTIONS ON DEG JW PUMPS.doc

Greg, Attached are information relating to Closed Cycle Cooling Water question. These are on IMS as well under # 199. We are still working on getting a copy of EPRI TR-107390 to you.

Best, Miranda Tan 805 781 9415 From: Pick, Greg [1]

Sent: Wednesday, October 27, 2010 9:07 AM To: Tan, Miranda Cc: DiabloCanyonNPEm Resource

Subject:

RE: Regional Inspection Spreadsheet See the attached questions from review of Closed Cooling Water, Open Cycle Cooling Water & FO Chemistry From: Tan, Miranda [2]

Sent: Wednesday, October 27, 2010 8:14 AM To: Pick, Greg Cc: Grebel, Terence

Subject:

Regional Inspection Spreadsheet

Greg, Attached is the regional inspection spreadsheet.

Best, Miranda Tan 805 781 9415

<<NRC Regional Inspection QA Spreadsheet 102610.xls>>

1

Hearing Identifier: DiabloCanyon_LicenseRenewal_NonPublic Email Number: 2160 Mail Envelope Properties (D065043718A59C4B99DDA1862BB067DE01BA2429)

Subject:

RE: Regional Inspection Spreadsheet Sent Date: 11/1/2010 12:07:22 PM Received Date: 11/1/2010 12:07:31 PM From: Tan, Miranda Created By: M1TF@pge.com Recipients:

"Grebel, Terence" <TLG1@pge.com>

Tracking Status: None "Pick, Greg" <Greg.Pick@nrc.gov>

Tracking Status: None Post Office: exchange12.Utility.pge.com Files Size Date & Time MESSAGE 881 11/1/2010 12:07:31 PM deg jw pp U1.pdf 323424 RESPONSE TO NRC QUESTIONS ON DEG JW PUMPS.doc 30272 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

RESPONSE TO NRC QUESTIONS ON DEG JW PUMPS

-Larry Price 10/29/10 The Tell Tale leakage from the JW or oil seal - what causes leakage of this sort or leakage and what does it mean (i.e., what is wearing out)?

The "tell-tale" is a drain ported into the annulus which is the atmospheric side of both the mechanical seal and the lip seal. The mechanical seal is the pressure boundary for the Jacket Water Pump and seals the chromated jacket water within the pump pressure boundary. The lip seal forms a seal around the gear driven pump shaft at the atmosphere end of the bearing housing. The pump bearings are lubricated by the engine crankcase oil. Any leakage from the mechanical seal and / or the lip seal is allowed to drain out of the annulus between these two seals for the following reasons:

1. Prevents jacket water from getting into the crankcase in the event of mechanical seal leakage.

2. Prevents lube oil from getting into the jacket water system in the event of a lip seal failure.

3. Allows detection of jacket water leakage through the mechanical seal and or oil leakage through the lip seal.

What does tell-tale leakage mean (what is wearing out)?

Jacket water leakage from the tell-tale means that jacket water is leaking across the dynamic seal faces (between the rotating and stationary seal faces), between the shaft sleeve and mechanical seal bellows, or through the gasket that seals the Seal Plate to the Bearing Frame. Minor drips are normal for a mechanical seal as leakage across the seal face is required for lubrication and cooling. Leakage of oil out of the tell tale indicates oil is leaking past the lip seal. Minor seepage across a lip seal is normal and typically wouldn't result in any visible drips.

In conclusion the tell-tale will normally show signs of minor seepage. Significant leakage reveals there is a problem in the mechanical seal area of the pump and/or the oil seal. Oil seal leakage across the lip seal is never a catastrophic failure. The oil fed to this area is by splash lubrication rather than a pressurized source.

Can I get a vendor drawing or vendor manual drawing of the jacket water cooling pump? Specifically, I am interested in the location of the tell tale drain?

The Jacket Water Pump parts exploded view is attached to the email. The first page has been marked up with explanatory notes. The tell-tale drain is a port in the bearing frame which connects to the annulus between the mechanical seal and the oil lip seal.

For pump 1-1 shaft sleeve corrosion noted - what caused the corrosion? Is this expected?

Years ago the Maintenance Engineer noted a correlation between jacket water seepage out of the tell-tale and finding corrosion on the shaft sleeve under the mechanical seal bellows. Also it was noted that this leakage typically occurred following maintenance where the JW System was drained below the JW Pump. It was determined that draining down the system to support maintenance allowed oxygen access to the shaft sleeve area. The crevices between the mechanical seal bellows and the carbon steel shaft sleeve support corrosion in the presence of oxygen. This was confirmed by the fact that this condition did not occur when the JW level was kept above the mechanical seal elevation. Once the shaft sleeves were converted to stainless steel, this problem did not recur even when the JW system was drained below the seal elevation.

What is the average life of the JW pumps if we remove the pump 2-1 July 1992 mechanical seal problem from the data? I assume this failure resulted from the maintenance error that we discussed?

13 years Can I get a vendor drawing or vendor manual drawing of the jacket water cooling pump? Specifically, I am interested in the location of the tell tale drain?

Vendor manual parts drawing attached.

Copy of EPRI TR-107390, Technical Basis of Treatment Chemicals Used for Corrosion Control Copy to be provided by others.