ML061870222

Calvert Cliffs, Units 1 & 2 Update of Response to Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Basis Accidents at Pressurized Water Reactors

ML061870222
Person / Time
Site:	Calvert Cliffs
Issue date:	06/30/2006
From:	Spina J A Constellation Energy Group, Constellation Generation Group
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GL-04-002, TAC MC4672, TAC MC4673
Download: ML061870222 (3)

Text

James A. Spina Calvert Cliffs Nuclear Power Plant, Inc.Vice President 1650 Calvert Cliffs Parkway Lusby, Maryland 20657 410.495.4455 410.495.3500 Fax 0 Constellation Energy-Generation Group June 30, 2006 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:

Document Control Desk

SUBJECT:

Calvert Cliffs Nuclear Power Plant Unit Nos. 1 & 2; Docket Nos. 50-317 & 50-318 Update of Response to Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors (TAC Nos. MC4672 and MC4673)In Reference (a) the Nuclear Regulatory Commission requested that pressurized water reactors evaluate the Emergency Core Cooling System and Containment Spray System recirculation functions and, if appropriate, take additional actions to ensure system function.

In References (b) through (f), Calvert Cliffs provided information concerning our plans for resolving the vulnerabilities identified in the Generic Letter and requested an extension to the Generic Letter resolution schedule.

We noted in References (b)through (e) that we planned to install a dual-train self-cleaning strainer device in both Unit Nos. 1 and 2.Recently, as part of the project review process, Constellation Energy performed a comprehensive assessment to determine the most favorable project success path considering available active and passive strainer technologies.

The results of that assessment indicate that implementing a passive strainer is more likely to result in timely resolution of the vulnerabilities associated with this generic issue. Therefore, we have suspended project activities related to the active strainer including the necessary license amendment request, and are in the process of procuring a replacement passive strainer technology.

We will review our previous correspondence (submitted in References b through f) and provide updated information related to the passive strainer technology by October 1, 2006. We believe that this change in technology does not impact our approved extension for Unit I to February 24, 2008 and will address this as part of our October 1, 2006 update.f ILe J Document Control Desk June 30, 2006 Page 2 Should you have questions regarding this matter, please contact Mr. L. S. Larragoite at (410) 495-4922.STATE OF MARYLAND: TO WIT: COUNTY OF CALVERT I, James A. Spina, being duly sworn, state that I am Vice President

-Calvert Cliffs Nuclear Power Plant, Inc. (CCNPP), and that I am duly authorized to execute and file this response on behalf of CCNPP. To the best of my knowledge and belief, the statements contained in this document are true and correct. To the extent that these statements are not based on my personal knowledge, they are based upon information provided by other CCNPP employees and/or consultants.

Such information has been reviewed in accordance with company practice and I believe it to be reliable.110ýSubscribe and sworn before me, a Notary blic in and for the State of Maryland and County of , y, .0o this JO dayof 2006.WITNESS my Hand and Notarial Seal: My Commission Expires: Notary Public,//Date 'JAS/PSF/bjd

-,.Document Control Desk June 30, 2006 Page 3

REFERENCES:

(a) NRC Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors," dated September 13, 2004 (b) Letter from G. Vanderheyden (CCNPP) to Document Control Desk (NRC), dated March 3, 2005, Response to NRC Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors" (c) Letter from G. Vanderheyden (CCNPP) to Document Control Desk (NRC), dated July 15, 2005, Response to NRC Request for Additional Information Re: NRC Generic Letter 2004-02,"Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors" (d) Letter from G. Vanderheyden (CCNPP) to Document Control Desk (NRC), dated August 30, 2005, Response to NRC Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors" (e) Letter from J.E. Pollock (CCNPP) to Document Control Desk (NRC), dated November 29, 2005, Supplemental Response to NRC Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors" (f) Letter from J.A. Spina (CCNPP) to Document Control Desk (NRC), dated February 3, 2006, Supplemental Information Related to Response to NRC Generic Letter 2004-02 cc: P. D. Milano, NRC Resident Inspector, NRC S. J. Collins, NRC R. I. McLean, DNR