ML20245E130
| ML20245E130 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 01/05/1988 |
| From: | Shelton D TOLEDO EDISON CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 1611, TAC-65070, NUDOCS 8901110115 | |
| Download: ML20245E130 (2) | |
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TOLEDO EDISON A Centerar Energy Cynpany DONAU] C. 8HELTON Vce pressiett-Nucear Docket Number 50-346
' License Number NPF-3 Serial Number 1611 January 5,19($
United States Nuclear Regulatory Commission Document Control Desk Washington, D. C.
20555
Subject:
Clarification of License Amendment Request Regarding Turbine Stop-Valve Closure Time (TAC Number 65070)
Gentlemen:
The following provides clarification of the License Amendment Request submitted on March 23, 1987 (Serial Number 1354). This clarification involves Technical Specification. Table 3.3-13, Item 4.
The original request for change to this item's response time provided for a reduction in the cited response time from < 6 seconds to < 1 second.
Per discussion with Mr. A. V. DeAgazio of your staff on November 4, 1988, and as included in Technical Specification Amendment Number 125 (Log Number 2778 dated December 7, 1988), a double asterisk note has been added to this table for clarification as follows:
4.
Turbine Stop Valves **
<1
- The response time is to be the time elapsed from the main steam line low pressure trip condition until the TSV is fully closed.
This clarification vill aid in interpretation of the Technical Specification by personnel in that the response time of the Turbine Stop Valves (TSVs) is only taken credit for in a Main Steam Line Break accident as stated in the Safety Evaluation and included in the proposed Bases Sections B3/4.3.1 and B3/4.3.2 supporting the License Amendment Request. Per the Safety Evaluation, closure of the TSVs is required to prevent blowdown of both steam. generators (affected and unaffected), given the failure of the Main Steam Isolation Valves (MSIV).to close (i.e., the affected steam generator's MSIV does not provide effective isolation under reverse flow conditions in the steam line and.the~ unaffected steam generator's MSIV is assumed to fail to close per the h kDOC 7
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g THE TOLEOO EDISON COMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO, OHIO 43652 7
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D'ockat Nu ber 50-346 c
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Serial Number 1611 Page 2 single failure criteria). The closure of the TSVs within the specified response time vill prevent the pressure in both steam generators from dropping below the Steam and Feedvater Rupture Control System low pressure trip setpoint and will ensure that the Auxiliary Feedvater flow to the good steam generator is not affected.
No further action on this item is required.
If you have any questions concerning the above, please contact Mr. R. V._ Schrauder, Nuclear Licensing Manager, at (419) 249-2366.
Very truly yours, RMC/dlm cc P. M. Byron, DB-1 NRC Resident Inspector A. B. Davis, Regional-Administrator, NRC Region III T. B. Vambach, DB-1 NRC Senior Project Manager State of Ohio
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