ML032740127

Response to RAI on the Technical Specification Change to Remove the Charging Pumps from the Technical Specifications

ML032740127
Person / Time
Site:	Calvert Cliffs
Issue date:	09/25/2003
From:	Vanderheyden G Constellation Energy Group
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TAC MB6989, TAC MB6990
Download: ML032740127 (3)

Text

George Vanderheyden 1650 Calvert Cliffs Parkway Vice President Lusby, Maryland 20657 Calvert Cliffs Nuclear Power Plant 410 495-4455 Constellation Generation Group, LLC 410 495-3500 Fax Constellation Energy Group September 25, 2003 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 Response to Request for Additional Information, Technical Specification Change to Remove the Charging Pumps from the Technical Specifications (TAC Nos.

MB6989 and MB6990)

This letter provides the information requested in Reference (a), and supports and/or clarifies the information provided in Reference (b). This information does not affect the No Significant Hazards Consideration Determination or the Environmental Impact Review of Reference (b).

Requested Information:

The licenseeproposed to remove the chargingpumps from the Technical Specifications (TSs) because they have demonstrated that the chargingpumps are not requiredfor the small-break-loss-of-coolant accident. The chargingpumps are the only components capable of injecting boron and coolant into the reactorvessel above the 80-percentpower level or 1700psi In order to remove the chargingpumps from the TSs, we request that you demonstrate that the plant can mitigate the consequences of accidentsandtransientssuch as anticipatedtransientwithout scram (A TWS) and steam generatortube rupture (SGTR), which require boron and coolant injection at power levels above 80 percent or pressure greater than 1700 psi without reliance on the chargingpumps. If the chargingpumps are required to mitigate the consequences of design-basis accidents and transients such as ATWS and a SGTR, then they satisfy the requirementsof Criterion3 of 10 CFR 50.36for inclusion in the TSs.

CCNPP Response:

The charging pumps are not required to mitigate the consequences of any design basis accident or transient. Specific information related to the two events discussed is provided.

The charging pumps are not required to mitigate the consequences of a SGTR at Calvert Cliffs. Only the high-pressure safety injection pumps are credited in the safety analysis to maintain inventory and satisfy boration requirements during a SGTR. Charging pumps are not required to mitigate the consequences of this event. The Calvert Cliffs Emergency Operating Procedures for SGTR currently instruct the operators to start all available charging pumps in order to maintain pressurizer level. The Calvert Cliffs Technical A1o

Document Control Desk September 25, 2003 Page 2 Requirements Manual requires two boration paths (including a charging pump) to be operable in Mode 1.

This requirement will not be deleted as part of the proposed Technical Specification change.

The SGTR accident analysis does assume that all three charging pumps are available at the start of the transient. This assumption delays the reactor trip on low pressurizer pressure and maximizes the calculated radiological consequences. Without charging pumps, the reactor trip would occur sooner and Reactor Coolant System pressure would decrease more rapidly, reducing the primary-to-secondary leakage. Therefore, maintaining the assumption that charging pumps are available serves to maximize the event consequences. This assumption would remain in the accident analysis after the Technical Specification is changed as long as it maximizes the event consequences.

The charging pumps are not required to mitigate the consequences of an ATWS at Calvert Cliffs. As noted in Reference (c), Calvert Cliffs has installed a Diverse Scram System (DSS). The Nuclear Regulatory Commission concluded in Reference (d) that the DSS met the requirements of 10 CFR 50.62.

Reference (e) stated that the installation of the DSS, diverse turbine trip and diverse auxiliary feedwater actuation system maintain the probability and consequences of an ATWS as low, and eliminate the need to consider an ATWS as a design basis event.

Therefore, because charging pumps are not required to mitigate the consequences of a design basis accident, such as a SGTR, and an ATWS is not assumed to occur, the charging pumps do not satisfy Criterion 3 of 10 CFR 50.36 and do not need to be maintained in the Technical Specifications.

I declare under penalty of perjury that the foregoing is true and correct. Executed on September 25, 2003.

Should you have questions regarding this matter, we will be pleased to scuss them with you.

Ve urs, GV/DJMlbjd

REFERENCES:

(a) Letter from G. S. Vissing (NRC) to G. Vanderheyden (CCNPP), dated August 8, 2003, Calvert Cliffs Nuclear Power Plant, Unit Nos. I and 2, Request for Additional Information, Technical Specification Change to Remove the Charging Pumps from the Technical Specifications (TAC Nos. MB6989 and MB6990)

(b) Letter from P. E. Katz (CCNPP) to Document Control Desk (NRC), dated December 13, 2002, License Amendment Request: Removal of the Charging Pumps from the Emergency Core Cooling System Technical Specification (c) Letter from A. W. Dromerick (NRC) to C. H. Cruse (BGE), dated October 2, 1997, Issuance of Amendments from Calvert Cliffs Nuclear Power Plant Unit 1 (TAC No. M95181) and Unit No. 2 (TAC No. M95182)

(d) Letter from S. A. McNeil (NRC) to J. A. Tiernan (BGE), dated November 2, 1988, Safety Evaluation Concerning Conformance to the ATWS Rule (TAC Nos. 59079 and 59080)

Document Control Desk September 25, 2003 Page 3 (e) Letter from C. H. Cruse (CCNPP) to Document Control Desk (NRC), dated July 31, 1997, Response to Request for Additional Information Regarding the Technical Specification Change to the Moderator Temperature Coefficient (TAC Nos. M95181 and M95182) cc: J. Petro, Esquire H. J. Miller, NRC J. E. Silberg, Esquire Resident Inspector, NRC Director, Project Directorate I-1, NRC R. I. McLean, DNR G. S. Vissing, NRC S