View source for BSEP-91-0191, Part 21 Rept Re Discrepancy Noted Between Torque Indicated by motor-actuator Characterization Sys & Output Torque Measured by Limitorque Actuator Test Stand.Initially Reported on 910426.Vendor Contacted Re Software Problem

{{Adams
| number = ML20073K886
| issue date = 04/29/1991
| title = Part 21 Rept Re Discrepancy Noted Between Torque Indicated by motor-actuator Characterization Sys & Output Torque Measured by Limitorque Actuator Test Stand.Initially Reported on 910426.Vendor Contacted Re Software Problem
| author name = Spencer J
| author affiliation = CAROLINA POWER &amp; LIGHT CO.
| addressee name = Murley T
| addressee affiliation = NRC OFFICE OF NUCLEAR REACTOR REGULATION (NRR)
| docket = 05000324, 05000325
| license number = 
| contact person = 
| case reference number = REF-PT21-91
| document report number = BSEP-91-0191, BSEP-91-191, NUDOCS 9105130109
| document type = DEFICIENCY REPORTS (PER 10CFR50.55E &amp; PART 21), TEXT-SAFETY REPORT
| page count = 5
}}

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CF&L                                                    -
Carolina Power & Light Company-4 Brunswick Nuclear Project l                                                                                           P.-O. Box 10429                                                   .
i                                                                                 Southport, NC 28461-0429                                                              i
?                                                                                            April 29, 1991 l
i i                        FILE:           B09-13520                                                                                            10CFR21 l                       SERIAL:. BSEP/91-0191 i
i                       Mr. Thomas E. Murley, Director                                                                           ,
!                       Office of Nuclear Reactor Regulation 1 White Flint North 11555 Rockville Pike j                       Rockville, Maryland 20852 i                                                       BRUNSWICK STEAM ELECTRIC PLANT UNITS 1 AND 2 i                                                                               DOCKET NO. 50-325 AND 50-324
;                                                                              LICENSE NO. DPR-71 AND DPR-62 I                                                 NOTIFICATION OF A 10CFR21 REPORTABLE OCCURRENCE

==Dear Mr. Murley:==

l i                       This confirms the telephone conversation at 1505 hours on April 26, i                       1991 between Mr. Robert Pettis (of your staff) and Mr. Michael Foss l                        (of my staff) which satisfied the requirements of 10CFR21 reporting l                       criteria. It-reported an apparent deviation in the software used to
;                       test Limitorque SMB-00 actuators, that was supplied by Limitorque.
,                       Corporation for use with its Motor Actuator Characterization (MAC) l                       Systems.                                                                               --
t l
l i
l                                                                                                  Very truly yours, y,
i t
hd.9We$k.                                                '
;                                                                                                  J. W. Spencer, General Manager l-                                                                                                 Brunswick Nuclear Project l                       GMT/gmt
'                       Enclosure
#                       cc:     Mr. S . . D.                                Ebneter i                               Mr. N.'B. Le
!                              Mr. R..L. Prevatte                                                                                                                       )
+
l:                                                                                                                                                                 1 l -:                  i105130109 91041.9 PDR j                            ADOCK 05000324                                                                                                                             l
* PDR                                                                            .
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==SUMMARY==
review of motor operated                                         '
Power & Light's  (CP&
Letter      L) a 10-CFR-21 reportable 89-10, During Carolina valve testing per Generic         discrepancy                   between data obtained (MAC) Systems A
identified.
iscue was our two Motor Actuator Characterization              and the BSEP Limitorque utilizing           Limitorque Corporation,i n of the accuracy ofThis                        the actuators.
supplied by theActuator on Test  Stand Limitorque  led          to SMB-00       an    investigat there    in   o evident an performed          actuators      showed testing                                                   by the MAC System and the investigation on SMB-00                                               Actuator Test Stand.
difference between the torque indicated output torque measured at the BSEP Limitorqueftware              diameter.       Due to error thisresulting The    variation is explained as a possible so xpected to disagree by from the differences in assumed worm-gear                                       f test data dif ference in diameter, the two systems are eThis is supporte about 14%.                                                                     1991. In the (several test   runs) gathered1991 between January 5, during    to January Valvethe program, MAC  20, a difference performed                                              to the conservatism applied    and the context of the overall Motor      pressure,      operatorof  required thrust,14%inshould  most have
;           when calculating differential A potential error of 14% will not,ility, However                                           Engin February 15, 1991 i
l           required torque range.
(EER)cases, 91-0056produce completed               a onUnit concern 1 andfor17valve on Unit operab          2) l
'           Evaluation Report                                                 and revealed one valve I            evaluated each safety-related                                   valve (10 onthat had be had been adjusted on January l            with an operability concern.                                            torque setting as j            Drain Line Inboard Isolation valve,                                                  8 foot-l            14,  1990 using the MAC System,                      maximum DP and it of  may have afoot-po 1020 psid.
i low as 20.9 evaluated   for a    realistic                       t Isolation System (PCIS) l pounds                                                                   i   d to isolate on                   a l
Therefore, valve this Group 1As     Primarya result Containmenmay  of this evaluation,was                        nothung clo break in the MSL Drain Line. (2-3405)                             isolation valve (2-B21-Feb. 19, 1991 a Caution Tag                                           i B21-F016 F019) valve closed, unless the outboardis                       LER 2-89-005 on closed l                                                           reported by                                      notor software problem was                            as used for SMB-3    tification l
A similar      Corporation's MAC System l
l Limitorque   This was reported by Limitorque               3        10-CFR-21 noActuators on O actuators.
'              on MAC Software Errors for SMB/SB/SBD-1989.
I i
l N
4 i
4 i

        .                                                                                                       i d
INITIAL CONDITIONS On April 24, 1991, when this item was determined to be 10CFR21 reportable, Unit 1 and 2 were in Cold Shutdown for Diesel Generator repairs.
EVENT DESCRIPTION 1991  a discrepancy       between data obtained In     early  January, utilizing the Motor Actuator Characterization (MAC) d                           i of the accuracy of the testing performed on Limitorque SMB-00 actuators.
EVENT INVESTIGATION j               The investigation into MAC System accuracy performed between January 5 and January 20 of 1991       SMB-00 noted  that theagainst actuator       output torque design indicated in operating i
a
:                                            as indicated by the MAC System, was higher differential pressure, than that indicated by testing on the BSEP Limitorque Actuator Test j
Stand.
The investigation into the variation revealed that the worm-gear ef fective radius is approximately 0.16            feet versus in radius          0.1827 used would feet used by the MAC System. The difference       This is supported by the 4
cause the data to disagree by about 14%.
limited amount of test data (several       testSystem The MAC    runs) gathered     during the may also measure          the MAC System Accuracy Testing.        result  input in     torque at losses mechanical       the drive in        sleeve rathe the This  could the actuator.
actuator totaling about 5 foot-pounds not being accounted for in the MAC System software .
91-0056 completed February The    Engineering Evaluation Report (EER)1991 determined there are 15,                      safety related valves thatMAC    hadSystems their torque   (see valves and 17 Unit 2       using     the  Limitorque switch settings Itset  evaluated each valve and has shown them to be 4
attachment 1).                             (Main Steam Line Drain Inboard         is operable except for the 2-B21-F016This is a PCIS Group 1 Isolation valve             that Isolation   Valve).above 500 psig except to support maintenance, normally closed
'                  draining or equalizing activities on the Main Steam Isolation Valves. It has a specified torque switch setting range of 27.9             foot-  to 35 foot-pounds.
The   as-left  torque   switch setting   was  29.6 pounds, as indicated by the MAC System, but           Thethis EERcould  be anaactual evaluated torque   setting as low  as  20.9   foot-pounds.                           foot-realistic torque required to close the actuator to be 21.8 pounds, which is above the 20.9 foot-pounds that may be available.
Therefore, the valve may not close against 1000 psid asHowever,   requiredthe     to isolate asetting break in  theclose will   MaintheSteam    Line valve     Drain aline.
against      DP of up to 966 presentAccordingly, until the torque switch setting can be adjusted psid.
within the allowable range, a Caution Tag (2-3405) has been hung to insure the 2-B21-F016 will not be opened above a conservative value of 850 psig unless the outboard isolation 2-B21-F019 is closed. The i

4 open torque switches of these valves are bypassed by jumpers and so are not at issue.
CORREC1IVE ACTIQld EER 91-0056 evaluated the operability of all SMB-00 Actuators whose(completed torque switches are presently set using the MAC System. -
2/15/91) and established corrective action items to:
: 1) .
Re-adjust the torque switches of Unit11/31/92.                                          1 Mos's to comply with the allowable torque ranges by 2).      Re-adjust the torque switches of Unit 12/31/91.                                         2 MOV's to comply with the allowable torque ranges by for      the     MAC  System reportability 3).      Evaluate 10CFR21             (Performed by this letter) potential error.
4).      Review the MAC System to determine if potential prob by 12/31/91.
Take actions to assure that 2-B21-F016                                                      will not be opened 2-B21-F019 is closed.
5).                  850    psig,     unless              the above (Completed on 2/19/91)
Additionally, thebetwo                             BSEP MAC Systems will corrected, or further evaluated and not be the      MAC System          can compensated for (Technical Support Memo 91-204).
Limitorque Corporation has been contacted about the potential software problem.
i
!          EVENT ASSESSMENT If tne closing torque switches of SMB-00 actuators were set below the design values using the MAC System, the valves would not                                                                fully Failure close under design basis dif ferential pressure conditions.o in conjunction with a single failure of the redundant isolation                                                        If this 1
valve,-could result in a breach of primary containment.
containment isolation valve failed to completely close due to a low torque setting, it is possible that the actual valve                                                             disk This    travel condition may stop below the 4% open limit switch setting. indicating closed on the Con would result in the             valve Reactor Turbine Gauge Board (RTGB) even though it would not be fully seated.
Consequently, the fact that the valve did not fully seat may not be detected by Operations.
insure the 2-B21-F016 remains
!            With compensatory action taken toshut under conditions where the a adequate, operability of all adjusted valves has been evaluated to f               exist.

   .',,   ,f .
3 ATTACHMENT 1 C
Safety-Related SMB-00 Motor Operatei Valves Set Up Using The MA-System DE9CRIPTION COMPONENT Unit 1           Unit 2 l
Core Spray Pump A Suppression P. ol 1-E21-FOO1A     2-E21-F001A Suction Valve Core Spray Pump B Suppression Pool 1-E21-F001B     2-E21-F001B
!                                               Suction Valve       Coolant Injection l                              2-E41-F004       High      Pressure       Storage    Tank l
1-E41-F004                       -(HPCI)     Condensate
;                                                Suction Valve HPCI~ Suppression Pool Suction Valve-l 1-E41-F041       2-E41-F041       HPCI Suppression _ Pool Suction Valve 4
1-E41-F042      2-E41-F042       Reactor Coolant Isolation Cooling NA               2-E51-F007                    Steam    Supply    Inboard
,                                                 (RCIC)
!                                                -Isolation Valve j                                                RCIC Steam Supply Outboard Isolation
                                                              ~
NA              2-E51-F008 j                                                Valve RCIC Condensate Storage Tank Suction NA              2-E51-F010 Valve-RCIC Pump Discharge Valve 1-E51-F012       2-E51-F012       RCIC Injection. Valve NA               2-E51-F013       RCIC Suppression Pool Suction Valve 1-E51-F029      2-E51-F029        RCIC Suppression Pool Suction Valve l
1-E51-F031      2-E51-F031        RCIC-Turbine Steam Supply: Valve? to j                                2-E51-F045 Residual- Heat Removal .(RHR) 1-E51-F045 1-E11-F049      NA
                                                 'Radwaste_ Inboard-Isolation Valve 2-B21-F016       MSL Drain Inboard Isolation Valve NA 2-B21-F019       MSL Drain Outboard Isolation. Valve NA                                Reactor Water Cleanup (RWCU) Inlet' 2-G31-F001 NA                                Inboard' Isolation Valve-2-G31-F004       RWCU Inlet Outboard Isolation Valve NA}}