ML120690258

Email, Request for Additional Information, Round 2, Amendment Request, Revise Technical Specification 3.3.5, Loss of Power (LOP) Diesel Generator (DG) Start Instrumentation, and Fsaru

ML120690258
Person / Time
Site:	Diablo Canyon
Issue date:	03/09/2012
From:	Joseph Sebrosky Plant Licensing Branch IV
To:	Soenen P Pacific Gas & Electric Co
Sebrosky J,NRR/DORL/LPL4 301-415-1132
References
TAC ME7520, TAC ME7521
Download: ML120690258 (1)

Text

From:

Sebrosky, Joseph Sent:

Friday, March 09, 2012 11:00 AM To:

Soenen, Philippe R Cc:

Lent, Susan; Burkhardt, Janet; 'Baldwin, Thomas (DCPP)'; Mazumdar, Subinoy; Stattel, Richard; Rahn, David

Subject:

RE: Request for Additional information for DCPP regarding TS 3.3.5 (ME7520 and ME 7521)

Philippe, By letter dated October 24, 2011, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML113010196), Pacific Gas and Electric Company (PG&E) submitted PG&E Letter DCL-11-072, License Amendment Request 11-06 Revision to Technical Specification 3.3.5, Loss of Power (LOP) Diesel Generator (DG) Start Instrumentation.

PG&E submitted a request for revision to Facility Operating License Nos. DPR-80 and DPR-82, revising Technical Specification (TS) 3.3.5 and final safety analysis report update (FSARU)

Appendix 6.2D and Sections 6.3, 15.3, and 15.4, revise the loss-of-coolant accident (LOCA) control room operator and offsite dose analysis of record described in the FSARU, and provide a new process for revising input values to this analysis.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information provided in your application and determined that the following additional information is required in order to complete its review. This request for additional information (RAI) was discussed with you on March 8, 2012. It was agreed that a response to this RAI would be provided by April 9, 2012.

Should the NRC determine that this RAI is no longer necessary prior to this date, the request will be withdrawn. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-1132 or via e-mail at joseph.sebrosky@nrc.gov. The NRC staff has determined that no security-related or proprietary information is contained herein.

Request for Additional Information

4. It is stated in clause 5.2 of Calculation No. 9000041128, Since the two sided T1A uncertainty is calculated at 95% Cl (CUDO = 1.96 X ), the one sided actuation point 95% probability will equal to (1.645 X ) or in other words: (1.645 / 1.96)

• CUDO.

Provide a technical justification as to why a one-sided probability distribution of channel uncertainty is used in calculating compliance to the NRC staffs position requiring a 95/95 tolerance limit for this application.

5. Clause 4, Inputs, lists reference accuracy for the devices used for 4.16 kV Bus Under-Voltage Relay & Timer setpoint calculations. Provide documentation to demonstrate that the reference accuracies used for all these devices are valid for a minimum of 95/95 confidence level as stated in RG 1.105., i.e. - 2 to 2.

6. Please provide diagrams indicating how the different devices described above are connected including the connection of the potential transformers and the relays, to enable the staff to understand the justifications requested above. Indicate what combination of relays are required to ensure that the required protective action is successfully achieved.