ML20211K288
| ML20211K288 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 11/03/1986 |
| From: | Kemper J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML20211K039 | List: |
| References | |
| IEB-85-003, IEB-85-3, NUDOCS 8611170118 | |
| Download: ML20211K288 (11) | |
Text
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PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET P.O. BOX 8699 PHILADELPHI A. PA.19101 JOHN S. MEMPER V IC E-PR E SID E N T ENosmas sessee Amo nasa ARCH November 3, 1986 1
Dr. Thomas E. Murley Docket Nos. 50-277 Regional Administrator, Region I 50-278 U.S. Nuclear Regulatory Commission 631 Park Ave.
King of Prussia, PA 19046
SUBJECT:
Peach Bottom Atomic Power Station, Units 2 & 3 I.E.Bulletin 85-03, " Motor-Operated Valve Common Mode Failure During Plant Transients Due to Improper Switch Settings"
REFERENCE:
Letter J. M. Taylor, NRC to J. M. Fulton (BWROG), Chairman BWR Owners Group, June 8, 1986
Dear Dr. Murley:
This submittal provides Philadelphia Electric Company's (PECo) revised response to I.E.Bulletin 85-03.
The referenced letter granted an extension for this submittal until October 1, 1986 to participating member utilities of the Boiling Water Reactor Owners Group (BWROG) Ad d
l Hoc Committee for I.E.Bulletin 85-03.
PECo was a full funding active participant in the BWROG effort.
In summary, this submittal contains the required design basis differential pressure information, scope of j
testing, and the schedule for completion of the remainder of the program for Peach Bottom Atomic Power Station as required by item (e) of Bulletin 85-03.
PEco's program is based on the findings of the BWROG study chartered to develop a generic position for items required i
for inclusion in this submittal. The requirements of the Bulletin are restated below along with PECo's responses.
i Requirements of Item (a) i
)
Item (a) of I.E.Bulletin 85-03 stated: " Review and document the design basis for the operation of each valve."(the motor-operated valves in the High Pressure Coolant Injection (HPCI) and the Reactor Core Isolation Coolant (RCIC) systems). "This documentation should l
include the maximum differential pressure expected during both opening i
and closing the valve for normal and abnormal events..."
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. Response to Item (a):
PECo used the BWROG developed methodology to calculate the maximum operating differential pressures of those subject valves which have an active safety function.
For HPCI/RCIC motor operated valves with no active safety function, a conservative methodology was used to calculate the maximum operating differential pressure. The attached table provides the pertinent valve information related to valve safety function and maximum design basis differential pressure. The calculated differential pressure was less than the originally specified design differential pressure for all but valves M0-23-57 & 58 and M0-13-39 &
41.
These valves serve as torus suction isolation valves to the HPCI and RCIC pumps, respectively. For these valves, the higher differential pressure is effective in the opening direction only.
All valves and associated motor operators subject to the concerns of IEB 85-03 are being reassessed relative to the newly generated operating requirements. This reassessment has demonstrated that adequate operating margin is available for all subject valves. Over 80% of the motor operators have been evaluated to date. All of these have been shown to have adequate design capability including MO-23-57 &
58 and M0-13-39 & 41.
The valve specifications will be revised to reflect the actual design capability of these motor-operated valves.
Requirements of Item (b)
Item (b) of I.E.Bulletin 85-03 states: "Using the results from Item (a), establish the correct switch settings. This shall include a program to review and revise, as necessary, the methods for selecting and setting all switches (i.e. torque, torque bypass, position limit, overload) for each valve operation (opening and closing)."
Response to Item (b):
PECo identified the need for correct switch setting and overload protection during the startup and early operation of Peach Bottom. At that time, programs were established to determine the correct settings and selections. The results of these programs have been incorporated into station maintenance procedure M-9.1.
The results of these l
earlier programs are summarized below:
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. i Limit Switches The closed limit switch (open torque switch bypass) is set so the valve is off the seat before the bypass is removed. This assures the full capability of the operator is available to unseat the valve. The applicable section of Maintenance Procedure M-9.1 states: "it (the 3
closed limit switch) shall operate after the valve comes off the seat."
In addition, redundant circuity currently exists which bypasses the open torque switch over the full opening stroke.
The open limit switch is set such that the valve does not strike the backseat. Maintenance Procedure M-9.1 states: "The open limit switch shall be set so that the valve does not coast into the Bonnet (backseated position)."
I Torque Switch l
Torque switch settings were re-evaluated in conjunction with the valve and operator manufacturers in the early operational phase of the plant. These settings were developed using the originally specified differential pressures. The results of this earlier evaluation are referenced by Maintenance Procedure M-9.1.
Overloads PECo recognized the need for special consideration of the overload sizing method due to the intermittent duty of the motor.
In 1975, PEco, in cooperation with Limitorque, established a special procedure to size MOV overloads. The overloads have been re-sized in E
accordance with that procedure.
In addition, PECo has in place at PBAPS a unique MOV control scheme which provides overload protection during normal manual operation and bypasses the overload during l
automatic (ECCS) operation. An overload trip can be overridden during l
manual operation. An overload trip at any time is annunciated in the l
control room.
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As part of its PBAPS 1.E.Bulletin 85-03 program, PECo is re-evaluating the minimum required torque switch settings. With the l
cooperation of the valve and operator vendors, this study will use the newly developed differential pressures.
In addition, a complete I
reassessment of the capabilities of each valve and operator is being performed to identify the operational margin.
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The need for further delineation of correct limit switch settings and overload sizes is also being reviewed. Overall completion of item (b) is scheduled for February 1987.
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Requirements of Item (c)
Item (c) of I.E.Bulletin 85-03 states: " Individual valve settings shall be changed, ar appropriate, to those established in item (b) above. Whether the valve setting is changed or not, the valve will be demonstrated to be opertble by testing the valve at the maximum differential pressure determined in Item (a) with the exception that testing motor-operated salves under conditions simulating a break in the line c'ontaining the valve is not required.
Otherwise, justification should be provided for any cases where testing with the maximum differential pressure cannot practicably be l
performed. This justification should include the alternative to maximum differential pressure testing which will be used to verify the ii correct settings."
Response to Item (c):
The final method operability testing at PBAPS is under evaluation. Differential pressure testing, signature tracing, and a combination of the two are being evaluated.
Revision of system in-service test procedures to demonstrate valve operability at maximum differential pressure is being considered.
Signature tracing is also being considered to assure the torque switch is set such that sufficient thrust is available to assure closure of the valve at the maximum differential pressure.
In addition, PEco is considering performing signature tracing on valves as they operate under pressure to demonstrate the margin available.
The need for operability testing of valves at their maximum differential pressure or by an acceptable alternate method is considered applicable to only those valves identified as having an active safety function. Although only HPCI/RCIC motor operated valves with active safety functions are subject to testing, all HPCI/RCIC motor-operated valves will be subject to the same torque switch setting, limit switch e
setting, and overload sizing procedures, as well as inservice testing pursuant to 10CFR 50.55a(g).
A decision on the type of testing to be perfcrmed is scheduled for December 31, 1986. No specific date can be given for test completion until the test method is finalized; however, it is expected that the testing will be completed for each unit during their next refuel outage.
Requirements of Item (d)
Item (d) of I.E.Bulletin 85-03 states: " Prepare or revise procedures to ensure that correct switch settings are determined and maintained through out the life of the plant."
5-t Response to Item (d):
i I
Any necessary revisions to Maintenance Procedure M.9.1 are scheduled to be completed by the Peach Bottom staff with Engineering 4
assistance by the end of the Peach Bottom Unit 2 refuel outage (April 1987).
Philadelphia Electric Company foresees the overall completion of
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the program to comply with the NRC November 15, 1987 timetable.
llowever, because of outage scheduling, equipment availability and the extensive modifications planned for the next Unit 3 refuel outage, some of the testing of Unit 3 valves may not be complete.
If this occurs, a program completion report will be submitted to the NRC by November 15, 1987 and a supplemental report detailing the Unit 3 findings will be submitted upon completion of valve testing.
It is expected that some of the testing may require HPCI and RCIC to be operable; if so, the valve testing will be completed upon Unit 3's return to power.
Sincerely.
S.f_r(
l ACC/mb/09308601 Copy to:
T. P. Johnson, Resident Site Inspector USNRC, Document Control Desk 4
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IEB 85-03. MOTOR. OPERATED VALVE PEACH BOTTOM APS DESIGN BASIS
SUMMARY
PHILADELPHI A ELECTRIC CO.
P&ID NORMAL BWROG SAFETY MAXIMUM SUBJECT DESCRIPTION POSITION REPORT DESIGN BASIS TO TEST VALVE NO.
SIZE /T PE I D. N O.
CLASS (I) op (OPEN/CLOSE)@ @ MAX 6P ($
(M-350 RCIC (Sys.13)
M o-2(5F 21 INTEC. TION VALVE CLOSE D 1
SAF(0/C)
(f 19 I /119 7) Psid Yes (o G ATE Mo-2.(31-27 MiniNt.n Ftov/ BYPASS CLostD 2.
sAF(o/c)
(12.95 /12.9 e)es;A Yes-VALV E 2.* GLoG6 Mo-2(3)-l8 CoNoe9 SATE StoRActE.
OPEN 3
$AF(C)
(-~ !3 I P5 d.
Ob i
TANH 8dCTiod VALVE' (o" Cx ATE 4*
$ AF (0/d)
(93 [ 34)ps 1 YES MO-2(5)- 41 Toaus SocTioiv closed MO If5)-39 ISOLATION VALVES fo" G AT E
^
M o-2.(5)-30 CST Test CLoSE D 5
NSAF
[2.7/1300)ps;d.
No RETORN VALVE 4* GLOBE 8
NSAF (IRt /Il9I)es;a No o
'M0- 2(31-20 IN1ecTioN VALVE OPEN TEST VALVE fo"6 ATE SHEET l oF 5
IEB 85-03 MOTOR OPERATED VALVE PEACH BOTTOM APS DESIGN BASIS
SUMMARY
PHILADELPHI A ELECTRIC CO.
p D
NORMAL BW ROG SAFETY MAXIMUM SUBJECT DESCRIPTION POSITION REPORT DESIGN BASIS TO TEST VALVE No SIZE /T PE I D. N O.
CLASS (D AP (OPEN/CLOSE)@) @ MAX 6P Gl (M-360T RclC Mo-2(3)- 132 TORBiWE ACCESSORY C LOS Q 9
SAF(0/C,)
(130 8 / 54)esid Yes
, C_ool:NG (JATCR VALVE 2 Gloer (M-359)
MO-2(31-13 l STEnn ApMissioN Closed I
SAF(0/c) b116 / Ill 6) ps;J YES VALVE 4" globe No-2(3)- 15 STE AM LlHE LJBOARD OPE N H.-
SAF(C)
(111(o /t Ilro)pf,a NO 150LATION V ALV E 3" G ATE M O-2(3)- l(o 5 TEAM LttJ E 00TBoARD OPE N g
ggy('C)
(lllb[litlo)ps,a.
No ISOLATioW VALVE 3 " G ATE Mo-4(5)l44 VAcoum BREAKER OPE td W
SAF(cd
(- / 4-l) Psid DS LINE ~IsotATioN VALVE.
3a gg 7g F
.5NEET 2. OPS
lEB 85-03.
MOTOR OPERATED VALVE PEACH BOTTOM APS DESlGN BASIS
SUMMARY
PHILADELPHI A ELE CTRIC CO.
P&ID NORMAL BW ROG SAFET Y MAXIMUM SUBJECT DESCRIPTION POSITION REPORT DESIGN BASIS TO TEST VALVE NO SIZE /T. PE ID.NO.
CLASS (1).
op (opEN/cLoSE)@) @ MAX 6P (3)
M-3(o S H P CI (Sys.2.3)
Mo-2.@-19 INTECT(oN VALVE C LOSED
[
SAF(0/C)
(112$ / ll4.3)psid YES 14 " G AT E Mo-2(31-25 MiNinum Fi_ow Clos ED Q
$Ar(o/c')
(l345 /134-0esid YES B'(PASS VALVE y Gtogt Mo-2(0- 17 CONDENSATE SToKA6E OPE W 3
ggy.(c}
(-/2_9)psid YES TANK SucTtoN VALVE.
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- G ATE ng2(3)- 5B TOROS focTioN C LOSED b
SAF(ofc)
( 9 3 / 343 psia N
N TI N VALVE S
[ s* G4rg Mo-2(31-5 7 MO-2(M-2J CST TEST RgTogg Clos E D 5
NSAF (2.7 /1350) pd No VALVE lO* G wsG MO-2(M-24 CST TEST I5oLSTIDW CLOSED (o
NshF (17/ \\350hd NO VALv E lO"G6TE SHEET 3er5
JEB 85-03. MOTOR OPERATED VALVE PEACH BOTTOM APS DESIGN BASIS
SUMMARY
PHILADELPHIA ELECTRIC CO.
p&lD NORMAL BW ROG SAFETY MAXIMUM SUBJECT DESCRIPTION POSITION REPORT DESIGN BASIS TO TEST VALyE NO.
SIZE /T. PE ID.NO.
CLASS (I).
AP (OPEN/CLOSE)2) @ MAX 6P G M-3G5 H Pc I 7
NSAF (2'7/1350)p3ca NO Ls AL E 4.'
ATE 8
blSAF (II2.3/ll43) psia No
. M D-2(5)-20 IeJJccrioW VALVE opeg TEST VALVE g,,
1 SdF(c/c)
(litb/lil(o)psid NES Mo -2(51-14 STE^n ADn'SS80rd C' S CO VALV E
\\0" G toSE MO-2(3)- 15 STEAM LWE InBaARD O PE t4 H
SAF(C)
( MI b[Illlo) P5;a No IsoL ATiod VALVE-10 G ATE
'l
- M o-2($-Ib STEAti LI4E OoTMRo OPEr4 g
ggp(c)
((j lb/li t b) p3;c!
NO IsoLATieta VALVE io
- G ATE MD-4(5)244A V/ toot 4 BREAKER OPEd Yll.
SAF(c)
(~ [4b 95id YE$
Lir4E ISotATION VALVE 3" GATE SHEET 4.or 5
o, NOTES FOR MOTOR OPERATED VALVE DESIGN BASIS StkNARY - PBAPS (1) The listed safety classifications delineate the active safety functions, which are considered to be within the plant design basis, of all valves subject to IEB 85-03. These safety classifications were established as part of the BWROG effort to develop a conmon BWR methodology that Individual utilities may utilize in responding to the bulletin. PECo concurs with these classifications as they relate to the requirements of IEB 85-03 with the following exception to account for a non-generic design feature:
The HPCI steam admission valve (M0-23-14) has an active safety function to close for reactor isolation.
The classifications are:
SAF(0), SAF(C), SAF(0/C) - Active safety function identified in open, close and open/close directions, respectively. NSAF - No active safety function identified within the plant design basis.
(2) The listed differential pressures represent the maxinun expected values which the valves would be subjected to during operation simultaneous with events considered within the plant design basis. For those valves that the BWROG considered as having an active safety function, the values were generated by methodologies developed by the BWROG. Maxinun operating differential pressures for all other valves were generated from conservative methodologies developed outside the scope of the BWROG.
In all cases, the maxinun operating differential pressures shall form the basis for establishing the mininun torque switch settings.
(3) Valves subject to maxinun differential pressure testing (or acceptable alternate) are those identified as having an active safety function with the exception of those valves whose sole safety function is for isolation of a 1ine break. Valves falling in this category include the steam line isolation valves. These valves will be tested to the extent practical.
SHEET 5 or 5 TSN/pdO9158607 l
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COHiONWEALTH OF PEthSYLVANIA ss.
COUtRY OF PHIlJOELPHIA J. S. KEMPER, being first duly sworn, deposes and says:
That he is Vice President of the Engineering and Research Department of Philadelphla Electric Company; that he has read the foregoing response to I.E.Bulletin 85-03 and knows the contents thereof; and that the statements and matters set forth therein are true and correct to the best of his knowledge, information and belief.
$[N A
,)6e Pres (den 1f V
Tngineering & Research Subscribed and sworn to f$
before me this 3 day of 4 /4,yp
, 1986
-./Gf Q
Notary Public MELANIE R. CAMPANELLA Notary Public, Phila&lphia. PhJadelphia Ca.
My Commiss:en bpires Tettuary 12,1990 I
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