ML082740489

Supplemental Response to Generic Letter 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors

ML082740489
Person / Time
Site:	Calvert Cliffs
Issue date:	09/30/2008
From:	Spina J Calvert Cliffs, Constellation Energy Group, Nuclear Generation Group
To:	Document Control Desk, Office of Nuclear Reactor Regulation
Shared Package
ML082740493	List: ML082740489 ML082740495 ML082740497
References
GL-04-002, TAC MC4672, TAC MC4673
Download: ML082740489 (3)

Text

Jame s A. Spina Vice President 0

/ **>

stella Ion Energy

../

Nuclear G erati n Group U. S. Nuclear Regulatory Commission Washington, DC 20555 Calvert Cliffs Nuclear Power Plant, Inc.

1650 Calvert Cliffs Parkway Lusby, Maryland 20657 410.495.5200 410.495-3500 Fax September 30, 2008 ATTENTION:

REFERENCES:

Document Control Desk Calvert Cliffs Nuclear Power Plant Unit Nos. I & 2; Docket Nos. 50-317 & 50-318 Supplemental Response to Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation during Design Basis Accidents at Pressurized Water Reactors" (a)

Letter from Mr. J.A. Spina (CCNPP) to Document Control Desk (NRC),

dated June 18, 2008, Request for Extension for Completion of Activities Related to Generic Letter 2004-02 (b)

Letter from Mr. D.V. Pickett (NRC) to Mr. J.A. Spina (CCNPP), dated June 30, 2008, Extension for Completion of Activities Related to Generic Letter 2004-02 (TAC Nos. MC4672 and MC4673)

(c)

Letter from Mr. J.A. Spina (CCNPP) to Document Control Desk (NRC),

dated February 29,

2008, Supplemental

Response

to Generic Letter 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation during Design Basis Accidents at Pressurized Water Reactors" In Reference (a), Calvert Cliffs Nuclear Power Plant (CCNPP) submitted a request for an extension to complete our response to the Nuclear Regulatory Commission (NRC) Generic Letter (GL) 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation during Design Basis Accidents at Pressurized Water Reactors." The NRC granted our extension request in Reference (b). In reference (a),

Calvert Cliffs committed to provide a revision to the supplemental response we provided in Reference (c).

This letter provides that revision as Attachments (1) and (2).

As noted in References (a) and (b) (and Attachment 1), additional testing is scheduled to be performed in the Fall of 2008 based on updated debris and chemical loads. Included in those chemical loads will be appropriate surrogates that reflect our requested containment buffer material change from trisodium phosphate to sodium tetraborate. This test series also has the potential to change the results of some of the evaluations provided in Attachment (1).

The current net positive suction head evaluations (in ) are based on testing performed in the Spring of 2008 with chemical surrogates for trisodium phosphate. As noted in Attachment (1), the results of this net positive suction head evaluation continue to show negative margin for the containment spray pumps, and an increased need to throttle flow

Document Control Desk September 30,2008 Page 2 to provide positive margin for the high pressure safety injection pumps.

We continue to refine these evaluations as more data are reviewed and more information comes to light.

After completion of the testing in the Fall of 2008, we will provide a revised supplemental response to the NRC reflecting the results of the testing and any changes in net positive suction head evaluations.

Should you have questions regarding this matter, please contact Mr. Jay S. Gaines at (410) 495-52 19.

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 reliab le.

Subscribed and sworn before me, a Notary Public in and for the State of Maryland and County of t?!J. d/CUj Q

, this~ day of (2rlernW,2008.

Oat;

~~~~~-

1MJ,.. /. 02011 WITNESS my Hand and Notarial Seal:

My Commission Expires:

JAS/PSF/bjd Attachments:

(1)

(2)

Supplemental Response to Generic Letter 2004-02 ECCS and CS System Figures

Document Control Desk September 30, 2008 Page 3 cc:

D. V. Pickett, NRC S. J. Collins, NRC Resident Inspector, NRC S. Gray, DNR