ML20246L160
| ML20246L160 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 08/28/1989 |
| From: | William Cahill, Walker R TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TXX-89600, NUDOCS 8909060265 | |
| Download: ML20246L160 (9) | |
Text
.
j '; <
[
M
. Log -# TXX-89600
" " " " _ ~ " "
File # 10010 C
C 910.3 filELECTRIC.
August 28, 1989 Enecutin Yur 14rsdest U
Y U..S. Nuclear Regulatory Commission Attn: Document Control Desk l.,
Washington, D. C.
20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET N05. 50-445-AND 50-446.
P
' ADVANCE FSAR' SUBMITTAL MAIN STEAM SAFETY VALVES i
Gentlemen:
This letter provides an advance copy of changes to be included in a future FSAR amendment. This change revises'the Main Steam Safety Valve blowdown from 5% to less' than or equal to 12% of the set pressure for the safety valve.
In order to facilitate NRC Staff review of this change, the attachment is organized as follows:'
1.
Draft revised FSAR pages, with change portions indicated by a bar-in the margin, as they are to appear in a future amendment.
2.
A detailed description / justification.for the change.
3.
A copy of a related SER section.
4.
A page containing the title of a " bullet" which consolidates and categorizes similar individual changes by subject and related SER section.
Y
- 5.
t I
i.
6909'060265 890E39
~ @ North Olive Street LB 81 Dallas, Texas 75201 PDR-ADOCK 05000445 A
FDC ~
T!
19600 Aug t 28, 1989 Page, of 2 5.
The bold / overstrike version of the revised FSAR pages referenced by the detailed description / justification for the changes identified above. The bold / overstrike version facilitates review of the revision by highlighting ~each' addition of new text in bold type font and overstriking with a slash (/) the portion of the text that is deleted.
Sincerely, Y
n4f-
)
William J. Cahill, Jr.
By:
c%04 bN Roger'4. Walker Manager, Nuclear Licensing MCP/ deb Attachment c - fir. R. D. Martin, Region IV Resident Inspectors, CPSES (3) l l
I I
I
is ~,
p
/
Attachment to TXX-89600-August 28. 1989 l-Advance FSAR Submittal Concerning j'
Main Steam Safety Valves-l' Ites 1 Draft Revised FSAR Pages 2
Item 2 tieta11ed Description / Justification for 3
l Changes Item 3 Related SER Secticn 4 and 5 Item 4 Bullet Title 6
Item 5 Bold /0verstrike Version of Revised FSAR 7
Pages y
l
.3 Page 1 of 7 1
I
_______)
ttachment'to TXX 89600 Aug:st~28, 1989-CPSES/F3AR r '.
P693 2 of'7 TABLE 10.3-2
[
^
Quantity per' unit
.20 l
Quantity per line 5
Safety class ASME B&PV Code,Section III, Class 2, seismic Category I Design pressure, psia 1250 l
Design temperature OF 600 Accumulation 31 of set pressure Blowdown 1125 of set pressure DRAFT Valve Settings and Rated Flow Set Rated Flow Pressure For Each Valve
~
(esia)
(1b/hr) 1200 893,160 1210 C00,607 1220,
908,055 1230 915,502 1250 930,397 Connections Inlet Dual Outlet Type Flanged Flanged Size, (n.
6 8 by 8 ANSI rating, Ib 1500 300 i
Attachner.t to TXX-89600 DETAILED DESCRIPTION Arg::st 28,1989
- Page 3 cf 7 FSAR Page (as amended)
Group Description Table 10.3-2 2
Revises the design basis for the main steam safety valve blowdown values from SE to less than or equal to 121 of set pressure.
Revision:
The main steam safety valve blowdown values are being revised from SE to less than or equal to 12% of set pressure. Westinghouse and CPE analyses show no edverse effects on LOCA or non-LOCA FSAR accident analyses and negligible radiological impact on control room operators or individuals at the site boundary for an increase in the blowdown value to 15%. The valve specifications permit blowdown of 12%. ASME Section III 1989 edition and onward changed the blowdown re-quirements to a pressure not lower than that specified in the valve design specifications.- The current FSAR value of SE is unnecessarily conservative.
FSAR Change Request Number: 89-415.1 Related SER Section: 10.3.1 SER/SSER Impact: No l
l l
l I
i 1
1
(
1
Attachment to TXX-89600
'- i August 28, 1989
' pige 4 of 7
~
10.3.1 Main Steam Supply System (Up to and Including the Main Steas
-Isolation Valves A cain steam line frem each of the four steam generators ccnveys the ste the high pressure turbine.
Each main stee.m line contains an MSIY u the pressur sf the main,e equalizing header that connects the main steam lines. pstream of steam lines from the steam generators out through containment up to the first moment restraint beyond the M5IVs are Quality Grouc 3 an Category I.
They are 1ccated in flood-and tornado protacted structures (se Sections 3.4.1 and 3.5.2 of this report), thereby satisfying the requirement of GDC 2 and Regulatory Guides 1.25 and 1.29.
and seismic Cate"ory I.The MSIVs, the integral bypass valves, an l
toASMESectionIIICodeClass1.)(The applicant has optionally upgraced this eq The MSIV actuators are Quality Group S.
The MSIVs and bypass valves are designed to close in 5 seconds u a main steam isolation valve closure sienal.
valves are designed to stop flow from eIther directiert.The isolation valves an Failure of one H5IV blowdown of more than ene steam generator.to close coincide If a steam line breaks u an MSIY and an MSIV on an unaffected steam generator fails to close,pstre seismic Category I turbine stop valves and turbine bypass valves w the non-thus preventing blowdown of the unaffected steam generator.
This process sarveo as an acceptable backup for this accident.
Seismic Categor valves (P02Vs) y I, Quality Group B safety valves and power-operated relief are provided for each steam generator.
ately outside the containment structure, upstream of the MSIVs.They are located The F03Vs (
per steam generator) are air operated and fail in the closed position uoon lo of air supply.
By Amendment 22 and a letter dated June 22, 1981, the applican with the as.*cciated piping and valvesverified that the PORVs are are designed to seismic Category I and Quality Group C requirements.
Thereliefvalvecontrolcircuitryandthevalve operator meet safety grade criteria (Class 1E).
of the PORVs to bring the plant to cold shutdown from the control room possible using only safety grade mechanical and electrical system in the eve of loss of offsite power or instrument air;.
The equipment required to ensure main steam isolation is protected ag effects of high-energy pipe breaks (see Section 3.6.1 of this report).
equipment is in tornado-missile protected structures, and it is located so th This it is not affected by internally generated missiles (see Section 3.5.1.1 of this report).
Guide 1.117 and Branch Technical Position ASB 3-1.Thus, this 3
of this equipment is discussed in Section 3.11 of this report. Environmental q Based on its review, the staff concludes that the main steam suppl design, up t.o and including the MSIVs, is in conformance with (1) y system 1
with respect to protection against seismic events, floods, tornadoes, mi
{
GDC 2 and 4 and pipe break effects; (2) GDC 34 with respect to heat removal capability; relating to the system's seismic and goality group clas 10-4 0
0
Attach;cnt~te TXX-89600
, August E8, 1989 Page 5 of 7 against tornado' missiles and high-and moderate-energy pipe breaks, and the l f~N.
MSIV closure time.
Therefore,.the system is acceptable, d
10.3.2 Main Steam' Supply System.(Downstream of the Main Steam Isolation Valves
)
l This section of the report evaluates the nonsafety-related portion of the main I
steam system, downstream of the MSIVs up to the turbine stop valves.
T."e porti of the main st um system is evaluated only as it may affect the saf3ty-related portien of the systaia in the event of a main staam line break, as ciscussed in Issue No. 1 in NUREG-0138.
The scope of the review of the main steam sucoly system (between the MSIVs and up to and including the turbine stop valves) included system descriptive information in Section 10.3 of the FSAR, flow enart and diagrams.
The main steam system for each unit is designed to deliver steam from the four steam generators to the high pressure turbine.
The main steam and turbine stat systems provide steam to their respective moisture-separator / reheaters, main and auxiliary feedwater pump turbines, turbine gland sealing system, feecwater h, eaters, and turbine bypass system.
The applicant has providad a listing of nonsafety-grade valves in lines branch-off the main steam lines downstream of the MSIVs.
If a main steam line breaks inside containment at the same time an MSIV on one of the other main steam liri fails, the plant can still be safely shut down.
The blowdown of the second steam generator through those branch lines containing normally open valves wii' not preclude safe shutdown because the plant will still have the required two
' team generators available to shut down the plant.
gq The design criteria and bases and design of the main steam supply system meet the cceeptance criteria in Section II of SRP 10.3.
Therefore, based on its review, the staff concludes that the main steam supply system between the main sfeam isolatdori valves and up to and including the turbine stop valves can perform its designed functions, and is, therefore, acceptable.
10.3.3 Steam and Feedwater Systems Materials General Design Criterion 1 requires, in part, that systems important to safet be designed to quality standards commensurate with the importance to safety c the functions to be performed. The materials utilized in the steam and feedw systems are reviewei for co.npl act with GDC 1.'
The nochanical properties of materials selected for Class 2 and 3 components of the steam and feedwater systems satisfy Appendix I of Section III of tne ASME Boiler and Pressure Vessel Code, and Parts A, B, or C of Section II of the Code.
The fracture toughness properties of ferritic materials satisfy the recuiremer.
of the Code.
The fracture toughness tests and mechanical properties reouirec by the Code provide reasonable assurance that ferritic materials will have adequate safety margins against the possibility of nonductile behavior or raci!
propagating fracture.
10-5
n IDR
~Attechment.to.TXX-89600 F/
LAugust 28, 1989 f ' 7 ' ' ' Pcga 6 cf 7 s
SECTION 10 - STEAM AND POWER-CONVERSION SYSTEM 10.3 Main Steam Sunnly Systeo l'
10.3.1 Main Steam Suno1r Syrten (un to and includino the Main i-l' Steam Isolation.Valvet)
.SPLB 16.
The FSAR has revised the Mein Steam Safety valve (77) blowdown from 51 to 12% of the set pressure for the safety valve.
l
1
' Attachment to TXX-89600
[ 7c <.
CPSES/FSAR
,, Arg:st 28. 1989 Peg 2 7 of 7 TABLE 10.3-2 MAIN STEAM SAFETY VALVES Quentity per unit
.20 Quar.tity.per,1ine 5
l Safety class ASME B&PV Code,Section III.
Class 2 seismic Category I l
Design pressure, psia 1250 Design temperature, OF 600-Accumulation 35 of set pressure Blowdown 1125 5% of set pressure 65 Valve Settings and Rated Flow Set Rated Flce Pressure For Each Valve tosia)
(1 b / h r")
1200 893,160 1210 900,607 1220 908.055 1230 915,502 1250 930,397 Connections Inlet Dual Outlet Type Flanged Flenged Size, in.
6 8 by 8 ANSI rating, Ib 1500 300
_ - _ _ _ _ _ _