ML20211J419
| ML20211J419 | |
| Person / Time | |
|---|---|
| Site: | 05200003 |
| Issue date: | 10/03/1997 |
| From: | Huffman W NRC (Affiliation Not Assigned) |
| To: | Liparulo N WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| References | |
| NUDOCS 9710080116 | |
| Download: ML20211J419 (4) | |
Text
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s October 3, 1997 Mr. Nicholas J. Liparulo, Manager Nuclear Safety and Regulatory Analysis Nuclear and Advanced Technology Division i
l Westinghouse Electric Corporation P.O. Box 355 l
I Pittsburgh, PA 15230
SUBJECT:
REQUESTS FOR ADDITIONAL INFORMATION (RAls) RELATED TO AP600 TECHNI-CAL SPECIFICATIONS (TS) ON MAIN STEAM ISOLATION VALVES
Dear Mr. Liparulo:
Westinghouse provided a revision to the Main Steam Isolation Valve TS (LCO 3.7.2) in revision 16 of the AP600 standard safety analysis report. The background for the TS changes is provided in Westinghouse letter NSD-NRC 5249 dated August 29, 1997.
The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information in the Westinghouse letter together with the associated changes to TS 3.7.2 and has some additional questions.
The RAls are enclosed with this letter.
If you have any questions regarding this matter, you may contact me at (301) 415-1141.
Sincerely, original signed by:
William C. Iluffman, Project Manager Standardization Project Directorate Division of Reactor Program Management Office of Nuclear Reactor Regulation Docket No. 52-003-
Enclosure:
As stated cc w/enclo: See next page DISTRIBUTION _:
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s Mr. Nicholas J. Liparulo Docket No.52-003 Westinghouse Electric Corporation AP600 cc: _Mr. B. A. McIntyre Mr. Russ Bell Advanced Plant Safety & Licensing Senior Project Manager, Programs Westinghouse Electric Corporation Nuclear Energy Institute Energy Systems Business Unit 1776 I Street, NW P.O. Box 355 Suite 300 Pittsburgh, PA 15230 Washington, DC 20006-3706 Mr. Cindy L. Haag Ms. Lynn Connor Advanced Plant Safety & Licensing Doc-Search Associates Westinghouse Electric Corporation Post Office Box 34 Energy Systems Business Unit Cabin John, MD 20818 Box 355 Pittsburgh, PA 15230 Dr. Craig D. Sawyer, Manager Advanced Reactor Programs Mr. Sterling Franks GE Nuclear Energy U.S.-Department of Energy 175 Curtner Avenue, MC-754 NE-50 San Jose, CA 95125 19901 Germantown Road Idaho Falls, ID 83415 Germantown, MD 20874 Mr. Robert H. Buchholz Mr. Frank A. Ross GE Nuclear Energy U.S. Department of Energy, NE-42 175 Curtner Avenue, MC-781 Office of LWR Safety and Technology San Jose, CA 95125 19901 Germantown Road Germantown, MD 20874 Barton Z. Cowan Esq.
Eckert Seamans therin & Mellott Mr. Charles Thompson, Nuclear Engineer 600 Grant Street 42nd Floor AP600 Certification Pittsburgh, PA 15219 NE-50 19901 Germantown Road Mr. Ed Rodwell, Manager Germantown MD 20874 PWR Design Certification Electric Power Research Institute 3412 Hillview Avenue Palo Alto, CA 94303
i l
RAls RELATED TO AP600 TECHNICAL SPECIFICATION ON l
MAIN STEAM ISOLATION VALVES (LCO 3.7.2) AND WESTINGHOUSE LETTER NSD-NRC-97-5249 DATED AUGUST 29. 1997 440.731 In LC0 3.7.2, the A.1 Action Completion time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for restoration of an inoperable MSIV or backup valves is not accept-able. The MSIV restoration completion time is inconsistent with the STS completion time of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
It may be acceptable to have the completion times of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> and 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, respectively, for restoration of an inoperable MSIV and backup valves, provided that sufficient justification can be provided.
Please correct this inconsistency.
440.732 SSAR Table 15.0-4b shows the steam line isolation valve closure delay time assumed in safety analysis to be 5 seconds. Technical specification surveillance requirements SR 3.7.2.1 and SR 3.7.2.2, specify the closure times of 5 seconds for the MSIVs and 10 seconds for the backup valves. The following inconsistencies related to the valve closures times have been noted:
a.
The Background on SR 3.7.2.2 states that "because the MSIV closure time is assumed for steam flow isolation in the
~
accident and containment analyses, the alternate downstream valves must meet the MSIV closure time." Based on this statement, the backup valves should have closure times of 5 seconds.
b.
A closure time of 10 seconds is indicated for the main steam to auxiliary steam header valve and the moisture separator reheat supply steam control valve listed in SSAR 10.3.2-4.
This does not appear to be consistent with the accident analyses closure time of 5 seconds, c.
SSAR Table 15.0-4b states that the "Steamline isolation valve closure" delay time is 5 seconds.
It is not clear if this applies to the MSIVs only or if the backup valves were also assumed to close within 5 seconds.
If different clo-sure time is used in the safety analyses for the backup valves, it should be included in Table 15.0-4b.
Westinghouse is requested to correct these inconsistencies.
440.733 AP600 SSAR Chapter 15 does not specifically identify which " main steam branch isolation valves" are credited in the safety analyses.
SSAR Table 15.0-8 cites the MSIV backup valves, but does not identify what valves these are. Table 15.0-8 should be revised to identify the specific main steam branch isolation valves credited in the accident analysis.
Enclosure
. \\.
. 440.734 SSAR Table 6.2.3-1, Containment Hechanical Penetration and Isolation Valves, identified the following main steam valves as the contain-l ment isolation valves:
PORV block valves (SGS-PL-V027A,B), safety j
relief valves (SGS-PL-V030, 031, 032A,B), MSIV bypass valves (SGS-PL-0240A,B), steamline condensate drain isolation valves (SGS-PL-V036A,B), in addition to the MSIVs (SGS-PL-V040A,B.
Because these main steam valves are containment isolation valves, they are required to be operable during MODES 1 through 4 operation per TS LCO 3.6.3, and are subject to surveillance requirements.
SR 3.6.3.4 and SR 3.6.3.5, respectively, require verification of the isolation times of these CIVs within the closure time limits specified in SSAR Section 6.2.3.
However, the PORY block valves and the condensate drain valve isolation times in SSAR Table 6.2.3-1 are shown as
" industry standard". What ai7 the rec. aired closure times for these valves, and are the closure tihm ec.isistent with the safety analy-sis assumption? These closure times should be in the SSAR.
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