ML20134F245
| ML20134F245 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 10/30/1996 |
| From: | Cruse C BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-96-06, GL-96-6, NUDOCS 9611050091 | |
| Download: ML20134F245 (5) | |
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1 CliAns.Es II. Cnest Baltimore Gas and Electric Company Vice President Calven Cliffs Nuclear Power Plant Nuclear Energy 1650 Calvert Cliffs Parkway Lusby, Maryland 20657 410 495-4455 October 30,1996 i
U. S. Nuclear Regulatory Commission i
Washington, DC 20555 ATTENTION:
Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 30-Day Response to Generic Letter 96-06,
" Assurance Of Equipment Operability and Containment Integrity During Design-Basis Accident Conditions"
REFERENCE:
(a)
Letter from Mr. B. K. Grimes (NRC) to Mr. C. H. Cruse (BGE), dated September 30, 1996, NRC Generic Letter 96-06:
" Assurance Of Equipment Operability and Containment Integrity During Design-Basis Accident Conditions" The purpose of this letter is to forward our 30-day response to Reference (a). The generic letter was issued to request a written summary of our evaluation to:
(1) determine if containment air cooler cooling water systems are susceptible to either wa:erhammer or two-phase flow conditions during postulated accident conditions; and, (2) determine if piping systems that penetrate the containment are susceptible to thermal expansion of fluid so that overpressurization of piping could occur.
Attachment (1) contains our detailed response to the information requested.
We regret that we were not offered the opportunity to comment on this generic letter prior to its release.
The public and industry are generally better served when they have been allowed to comment on proposed generic letters. We encourage the Nuclear Regulatory Commission to continue allowing public comment on future proposed generic letters and bulletins.
9611050091 961030 PDR ADOCK 05000317 P
PDR OD0051
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Document Control Desk l
October 30,1996 Page 2 Should you have questions regarding this matter, we will be pleased to discuss them with you.
4 Very truly yours, l
l' l
STATE OF MARYLAND
- TO WIT:
COUNTY OF CALVERT I hereby certify that on the.b0ll) day of
, 19 h, befor me, the subscriber, a Notary Public of the State of Maryland in and for LN u
. peisonally appeared Charles H. Cruse, being duly sworn, and states that he is Vice President p the Baltin. ore Gas and Electric Company, a corporation of the State of Maryland; that he provides tne foregoing.esponse for the purposes therein set forth; that the statements made are true and correct to the best of his knowledge, information, and belief; and that he was authorized to provide the response on behalf of said Corporation.
WITNESS my Hand and Notarial Seal:
M Notary Public My Commission Expires:
b Date CHC/JMO/ dim
Attachment:
(1)
Baltimore Gas & Electric Company's 30-Day Response to GL 96-06:
" Assurance Of Equipment Operability and Containment Integrity During Design-Basis Accident Conditions" cc:
D. A. Brune, Esquire H. J. Miller, NRC J. E. Silberg, Esquire Resident Inspector, NRC Director, Project Directorate 1-1, NRC R. I. McLean, DNR A. W. Dromerick, NRC J. H. Walter, PSC
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ATFACHMENT (1)
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j BALTIMORE GAS AND ELECTRIC COMPANY'S 30-DAY RESPONSE
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l TO GL 96-06:
" ASSURANCE OF EQUIPMENT OPERABILITY AND CONTAINMENT INTEGRITY i
DURING DESIGN-BASIS ACCIDENT CONDITIONS" l
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Calvert Cliffs Nuclear Power Plant Units 1 & 2 October 30,1996
ATTACHMENT (1)
BALTIMORE GAS AND ELECTRIC COMPANY'S 30-DAY RESPONSE TO GL 96-06: " ASSURANCE OF EQUIPMENT OPERABILITY AND CONTAINMENT INTEGRITY DURING DESIGN-BASIS ACCIDENT CONDITIONS" a
REOUIREn RESPONSE Within 30 days of the date of this generic letter, addressees are required to submit a written response indicating:
1) whether or not the requested actions will be completed:
Response
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The requested actions are (1) determine if containment air cooler (CAC) cooling water systems are susceptible to either waterhammer or two-phase flow conditions during postulated accident conditions and, (2) determine if piping systems that penetrate the containment are susceptible to thermal expansion of fluid so that overpressurization of piping could occur. Note that for Calvert Cliffs, Units I and 2, the containment spray system is an alternate, redundant containment cooling system to the CAC system.
For waterhammer, we will first evaluate whether the potential to create voiding in a CAC exists.
If voids are found to form during postulated accident conditions, then the potential for a waterhammer to form and its resulting magnitude will be evaluated to determine its impact on the system. Corrective actions will be taken if the scenario (i.e., loss-of-coolant accident / loss of offsite power [ concurrent] or main steam line break) is found to be credible. We are investigating the potential of addressing this issue through other industry efforts.
For two-phase flow, we have already evaluated the potential to create two phase flow conditions at the outlet of the CACs and associated downstream restrictions as part of the service water system design basis. However, the transient period, during which service water control valves are repositioned at the start of the design basis accident, will be reviewed. If required, a detailed analysis of this transient will be incorporated into the system design basis. Corrective actions t
will be taken if necessary.
For overpressurization, we will determine if liquid filled, safety-related piping systems that penetrate the containment are susceptible to the scenario described in the generic letter. Please note that providing piping systems with thermal relief protection from overpressure events was an initial design consideration. Evaluatmg the adequacy of thermal relief protection will require a review of the system drawings and plant operating procedures to determine if specific piping segments, in containment, can be isolated. The piping segments identified will be reviewed to determine if appropriate relief protection is provided. Corrective actions will be taken if necessary and may include procedure changes or system modifications.
2) whether or not the requested information will be submitted; and.
Respamic The requested summary information will be submitted.
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ATTACHMENT f1)
HALTIMORE GAS AND ELECTRIC COMPANY'S j
30-DAY RESPONSE TO GL 96-06: " ASSURANCE OF EQUIPMENT OPERABILITY AND CONTAINMENT INTEGRITY DURING DESIGN-BASIS ACCIDENT CONDITIONS" 3) whether or not the requested information will be submitted within the requested time period.
Respone Currently, we plan to develop an evaluation sufficient to determine the basis for continued operability of affected systems and components. By January 28, 1997, we will provide a summary status of our evaluations, an assessment of their impact on operability, and a schedule for implementing the results of the evaluation.
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