ML14035A550

RGN-I/PB 1 Response to Email from T. Gurdziel PNO-1-14-001, Calvert Cliffs

ML14035A550
Person / Time
Site:	Calvert Cliffs
Issue date:	01/30/2014
From:	Andrew Rosebrook Reactor Projects Branch 1
To:	Tom Gurdziel - No Known Affiliation
Rosebrook A
References
PNO-I-14-001
Download: ML14035A550 (1)

Text

From: Rosebrook, Andrew Sent: Thursday, January 30, 2014 3:31 PM To: Tom Gurdziel Cc: Jill Lyon; Bridget Frymire

Subject:

RE: PNO-1-14-001, Calvert Cliffs Tom Thank you for your question. Following the February 2010 dual unit scram, the NRC launched a Special Inspection. The Special Inspection Report was a standalone inspection report. The Inspection Report 50 317 & 318/2010006 (ADAMS Number ML101650723) Issued on June 14, 2010 which included a Preliminary White Finding and Four Green Findings associated with the Event.

One of the Green Findings (NCV 50-317&318/2010006-01) was a Non Cited Violation of 10 CFR 50 Appendix B Criterion XVI for Failure to Throughly Evaluate and Correct Degraded Conditions Associated with Auxiliary Building Roof Leakage. This was the weather related impact which initiated the February 2010 dual unit shutdown. Roof leakage from the auxiliary building allowed water intrusion into the 13.5 kV switchgear which caused a Current Transformer in the Switchgear to fault resulting in the loss of Reactor Cooling Pumps. While the 2010 and 2014 dual unit shutdown were caused by weather related impacts on different structures, the fact that both events involved snow and water entering 13.5 kV switchgear and resulting in a fault, additional inspection was determined to be warranted to determine if corrective actions and Extent of Condition reviews from 2010 should have precluded the 2014 event.

The failure of the 2B Emergency Diesel Generator to start in 2010 was the subject of the White Finding and was one of the primary reasons a Special Inspection was launched in 2010. The Final Significance Determination and Notice of Violation, EA-10-080 was issued on August 10, 2010 (ML102150484). A follow up Supplemental Inspection was completed in March 2011 and documented in Inspection Report 50-318/2011008 Issued on April 29, 2011 (ML111190104).

Typically, when an issue is documented in a Special Inspection Report it is not also discussed in the associated Integrated Inspection Report is order to avoid confusion.

The Circulating Water Pumps, Main Feed Pumps and Reactor Coolant pumps are 13.5 KV motors. The busses these motors are powered from are normally supplied from offsite power.

While these loads could be supplied from the main generator while at power, offsite power is required during plant startup, shutdown, and plant outage conditions. Understand when this plant was designed and built the utility owned both the plant and the power distribution system, thus economically where the busses were powered from made no difference as the utility did not bill itself. Additionally, that decision is outside the NRCs purview as it is a purely economic/business decision on the part of the licensee.

Feel free to contact me if you would like to discuss this further.

Thanks Andy Rosebrook Senior Project Engineer USNRC/RI/DRP/Branch 1

610-337-5199 From: Tom Gurdziel [1]

Sent: Monday, January 27, 2014 10:11 PM To: CHAIRMAN Resource Cc: Rosebrook, Andrew; Jill Lyon; Bridget Frymire

Subject:

PNO-1-14-001, Calvert Cliffs Good morning, At the bottom of this PNO is a statement that this is a repetitive, weather related failure, and a February 2010 event is cited.

For that event, I found EN#45709 and it did not say anything about weather. I did not see any update of it (looking ahead a few days only.)

Next I looked at Integrated Inspection Report 2010002 for these plants. I found the forced outage NRC inspection efforts in section 1R20.2a.

Section 1R20.2b, for Findings, states: No findings of significance were identified.

Where are weather effects on structures identified as a factor for the February 2010 event?

Why wasnt the failure to start of DG 2B explained in the Integrated Inspection Report? It wasnt even in the Inspection Scope.

And, given that the use of the words in house service transformer in Event Number 45709 is misleading, why would you do that? Why wouldnt circulating water pump motors be carried from the Units generated power? (Specifically, dont they have to pay taxes on the electric power (from off-site) that they use, so that the use of on-site-generated power would cost them less?)

Thank you, Tom Gurdziel