ML102000567
| ML102000567 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 07/19/2010 |
| From: | Richard Guzman Division of Operating Reactor Licensing |
| To: | Furio P Calvert Cliffs |
| Guzman R, NRR/DORL, 415-1030 | |
| References | |
| TAC ME3348, TAC ME3349 | |
| Download: ML102000567 (3) | |
Text
From:
Guzman, Richard Sent:
Monday, July 19, 2010 2:14 PM To:
Furio, Patricia S Cc:
Pickett, Douglas
Subject:
Follow-up RAIs re: License Amendment Request - Pressurizer Safety Valve Technical Specification Revision Hi Pat, Im backing up Doug this week. You recently provided an RAI supplemental response related to CCNPPs LAR dated January 29, 2010. The tech staff has follow-up questions to that supplemental response as shown below. As necessary, we can have a conference call to go over any items which may require further clarification to better ensure you satisfy the tech staffs questions/concerns. Please let me know when you can support a call for this week.
- Thanks, Rich Guzman 301-415-1030 Follow-up RAI questions re: License Amendment Request - Pressurizer Safety Valve Technical Specification Revision A. RAI 1 Response
- 1. The response indicated that evaluations were made for the loss of normal feedwater flow (LNFW) and feedwater line break (FLB) events initiated from Mode 3 conditions.
Discuss the methods for the evaluations and confirm that the methods used are NRC-approved methods or computer codes.
- 2. The initial RCS pressure of 700 psia was assumed for the evaluation of the LNFW and FLB events.
Address for the initial reactor coolant system (RCS) pressure of 700 psia assumed in the LNFW and FLB evaluation the compliance with Criterion 2 of 10 CFR 50.36(d)(2)(ii) that requires Technical Specification limiting conditions for operation (LCO) for a process variable that is an initial condition of a design basis or transient analysis that either assumes the failure of or presents a challenge to the integrity of a fission product barrier. It should be noted that the initial RCS pressure of 700 psia used in the evaluation is considered a process variable referred in Criterion 2.
- 3. The RAI response stated that for the LNFW and FLB evaluation, the transients were slow such that operator had enough time to implement emergency operating procedure (EOP) actions for consequences mitigation and prevent the RCS pressure from reaching the pressurizer safety valve (PSV) opening setpoint.
Discuss the results of the LNFW and FLB evaluation to show the times (mission times) that PSV setpoint would open for cases without operator actions, and discuss the EOP actions credited in the evaluation and demonstrate that the operators would reduce, in
accordance with the EOP actions, the RCS pressure below PSV setpoint before the calculated mission times reached.
B. RAI 3 Response
- 1. The response indicated that the rate of change of power-high trip was used to terminate the control element assembly (CEA) withdrawal event initiated from Mode 3, and that the event for Mode 3 was bounded by the event initiated from Mode 2, which relied on the variable high power trip for event termination.
Discuss the allowable value for the rate of change of power-high trip and demonstrate that the trip on the signal from the rate of change of power-high trip for the Mode 3 event occurred sooner than that for the Mode 2 event, resulting in a lower RCS pressure during the Mode 3 event.
- 2. Follow-up RAI A.2 above is applicable to the evaluation of the CEA ejection event discussed in the RAI 2 response, as well as the CEA withdrawal and excess load events discussed in the RAI 3 response. The above follow-up RAI A.3 is also applicable to the excess load event.
E-mail Properties Mail Envelope Properties (92E0E77F3622DA40B501E8D45083D5D9508499C9DF)
Subject:
Follow-up RAIs re: License Amendment Request - Pressurizer Safety Valve Technical Specification Revision Sent Date: 7/19/2010 2:14:26 PM Received Date: 7/19/2010 2:14:00 PM From: Guzman, Richard Created By: Richard.Guzman@nrc.gov Recipients:
Patricia.Furio@cengllc.com (Furio, Patricia S)
Tracking Status: None Douglas.Pickett@nrc.gov (Pickett, Douglas)
Tracking Status: None Post Office:
HQCLSTR01.nrc.gov Files Size Date & Time MESSAGE 18567 7/19/2010 Options Expiration Date:
Priority: olImportanceNormal ReplyRequested: False Return Notification: False Sensitivity: olNormal Recipients received: