ML20196F269
| ML20196F269 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 11/30/1998 |
| From: | Cruse C BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-96-06, GL-96-6, NUDOCS 9812040233 | |
| Download: ML20196F269 (2) | |
Text
Curntzs 11. CRUSE Baltimore Gas and Electric Company Vice President Calvert Cliffs Nuclear Power Plant Nuclear Energy 1650 Calvert Cliffs Parkway Lusby, Maryland 20657 410 495-4455 November 30,1998 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:
Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit No 2; Docket No 50-318 Withdrawal of License Amendment Request: Modification t) the Service Water IIead Tanks
REFERENCES:
(a)
Letter from Mr. C.11. Cruse (BGE) to NRC Document Control Desk, dated March 6,1997, License Amendment Request: Modification to the Service Water Head Tanks (b)
Letter from Mr. C. II. Cruse (BGE) to NRC Document Control Desk, dated January 28,1997,120-Day Response to Generic Letter 96-06,
" Assurance of Equipment Operability and Containment Integrity During Design-Basis Accident Conditions"
}
(c)
Letter from Mr. C.11. Cruse (BGE) to NRC Document Control Desk, 6
dated February 20, 1998, Revision to Commitments in 120-Day Response to Generic Letter 96-06, " Assurance of Equipment Operability and Containment Integrity During Design-Basis Accident Conditions"
- b. @ A In March 1997, Baltimore Gas and Electric Company submitted a license amendment request related to a modification of the Unit 2 Service Water System head tanks (Reference a). The modification was in response to the water hammer concerns expressed in Generic Letter 96-06, " Assurance of Equipment Operability and Containment Integrity During Design-Basis Accident Conditions". This letter is a withdrawal of that license amendment request.
Our initial calculations indicated that a water hammer in the Service Water System at the containment air coolers would produce a pressure in excess of 1200 psi. A nitrogen system intended to prevent the water hammer by increasing the pressure in the Unit 2 service water head tanks was installed but never placed in operation. The nitrogen system intended for Unit I was never installed. The decision to make the modification in Unit 2 and the later decision not to connect it to the system, or to install it in Unit 1, was ADOCK05000318[
9812040233 981130 PDR 1
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Document Control Desk November 30,19989 Page 2
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communicated to the NRC by Re'.erences(b) and (c). Further analysis established that the initial analysis was too conservative and the current projected water hammer pressure is conservatively estimated to be about 200 psi. At this pressure, a modification to the head tanks is not necessary as the system can be made robust enough to withstand the water hammer and meet full design qualification.
We have been working with the Electric Power Research Institute (EPRI) and the Nuclear Energy Institute (NEI) to perform a more extensive analysis. From the results so far, we believe the actual pressure produced by a water hammer will be considerably lower than 200 psi and no modifications to the system will be necessary. Even if this analysis does not show a further reduced pressure, the modification to the head tanks described in Reference (a) will still not be necessary. If any modifications are required for any reason, they will be evaluated for unreviewed safety questions.
I When the EPRI/NEl project is complete, we will inform the NRC of our plant-specific position as a final response to Generic Letter 96-06.
Should you have questions regarding this matter, we will be pleased to discuss them with you.
Very truly yours, 5f&
p CHC/EMT/ dim cc:
R. S. Fleishman, Esquire H. J. Miller, NRC J. E. Silberg, Esquire Resident Inspector, NRC S. S. Bajwa, NRC R. I. McLean, DNR A. W. Dromerick, NRC J. H. Walter, PSC t
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