ML20084A933
| ML20084A933 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 04/13/1984 |
| From: | Jackie Cook CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 28088, 84-01-#2, 84-1-#2, OL, OM, NUDOCS 8404260022 | |
| Download: ML20084A933 (10) | |
Text
-_
D/n B Consumers Power
. tames W Cook Oh b0f Vice President - Projects, Engineering and Construction General offices: 1945 West Parnalt Road, Jackson, MI 49201 e (517) 788-0453 April 13, 1984 84-01 #2 Mr J G Keppler, Regional Administrator US Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137 MIDLAND ENERGY CENTER PROJECT DOCKET NOS 50-329 AND 50-330 EXCESSIVE VOLTAGE DROP -
AUXILIARY FEEDWATER VALVE ACTUATORS FILE:
0.4.9.88 SERIAL:
28088
Reference:
J W Cook letter to J G Keppler, Same Subject, Serial 28001, dated February 3, 1984 This letter is an interim report of a 10CFR50.55(e) condition involving
~
excessive voltage drop in power cables supplying auxiliary feedwater system DC valve actuators. The attachment to this letter describes the concern and summarizes the investigation and corrective action taking place.
It has been determined that this condition, if it had remained uncorrected, would have affected the safety of operations at the Midland Plant.
Another report, either interim or final.will be sent on or before August 17, 1984 JWC/AHB/1r
~
Attachments:
(1) MCAR-80, Interim Report 2, dated March 26, 1984 CC: Document Control Desk, NRC Washington, DC RJCook, NRC Resident Inspector Midland Nuclear Plant DSHood, USNRC Office of NRR gpjB N INPO Records Center OC0484-0004A-MP01 8404260022 840413
}
gDRADOCK05000 ggj
,(
2 Serial 28088 84-01 #2 l
OM/0L SERVICE LIST Mr Frank J Kelley Atomic Safety & Licensing Attorney General of the Appeal Board State of Michigan U S Nuclear Regulatory Commission Ms Carole Steinberg Washington, DC 20555 Assistant Attorney General Environmental Protection Division Mr C R Stephens (3) 720 Law Building Chief, Docketing & Services Lansing, MI 48913 U S Nuclear Regulatory Commission Office of the Secretary Washington, DC 20555 Mr Myron M Cherry, Esq Suite 3700 Ms Mary Sinclair Three First National Plaza 5711 Summerset Street Chicago, IL 60602 Midland, MI 48640 Mr Wendell H Marshall Mr William D Paton, Esq RFD 10 Counsel for the NRC Staff Midland, MI 48640 U S Nuclear Regulatory Commission Washington, DC 20555 Mr Charles Bechhoefer, Esq Atomic Safety & Licensing Atomic Safety & Licensing
, Board Panel Board Panel U S Nuclear Regulatory-Commission U S Nuclear Regulatory Commission East-West Towers, Room E-413 Washington, DC 20555 Bethesda, MD 20014 Ms Barbara Stamaris
-Dr Frederick P Cowan 5795 North River Road 6152 N Verde Trail Rt 3.
Apt B-125 Freeland, MI 48623 Boca Raton, FL 33433 Dr Jerry Harbour Mr Fred C Williams Atomic-Safety & Licensing Isham.. Lincoln & Beale Board Panel 1120 Connecticut Ave, NW, Suite 840 U S Nuclear Regulatory Commission Washington, DC 20036 East-West Towers, Room E-454 Bethesda, MD 20014~
Mr James E Brunner, Esq Consumers Power Company Mr.M I Miller, Esq 212 West Michigan Avenue Isham, Lincoln & Beale Jackson, MI 49201 Three First-National' Plaza 52nd-Floor Chicago, IL 60602' n
OC0484-0004A-MP01-b
_n -
1.-
3 Serial 28088 84-01 #2 Mr D F Judd Babcock & Wilcox PO Box 1260 Mr John Demeester, Esq Lynchburg, VA 24505 Dow Chemical Building Michigan Division l
.Mr Steve Gadler, Esq Midland MI 48640 2120 Carter Avenue St Paul, MN 55108 Ms Lynne Bernabei 4
Government Accountability Project Mr_P Robert Brown 1901 Q Street, NW
-. Clark, Klein & Beaumont Washington, DC 20009 1600 First Federal Bldg Woodward Ave Detroit, MI 48226 3/14/84
^
.'OC0484-0004A-MP01
=
=. -
Attach:nent 1 Serial 28088
")
8h-01 #2 I 4 6 3 2 i Bechtel Associates Professional Corporation g
-4 146370 a
SUBJECT:
MCAR 80, Rev 1 (issued January 24, 1984) g Auxiliary Feedwater DC Reversing Valve Actuator as Excessive Power Cable Voltage Drop
]
M INTERTM REPORT 2 g
DATE:
March 26, 1984 4
PROJRCT:
Consumers Power Company Midland Plant Units 1 and 2 7_
Bechtel Job 7220 d
3 Introduction 3
Ee This report provides the interim status and course of corrective 1
action required pursuant to MCAR 80.
]
Description of Concern 7
]5 The voltage drop in the power cables for the auxiliary feedwater 3
system de reversing valve actuator motors is greater than the value 1
considered when the cables were sized. The voltage drop has now been calculated [ Calculation QPE-18(Q), approved December 21, 1983), and
-=
the results' indicate that voltage at the associated motor-cperated j
valves is below the allowable limits for proper operation.
[
N Probable Cause Additional valtage drop resulting from the total circuit length j
between starting devices and actuator motor was not considered in the l
design of these specific items.
3 Summary of Investigation and Historical Background
~
^
The investigation into the adequacy of de reversing valve actuator y
circuits was initiated as a result of TPO Problem Alert 82-02, a
Revision 0 (DC Power Circuit Starters and Sizes of Cables for Motors y
and Valve Actuator Motors). The problem alert identified a voltage 9
deficiency in these types of circuits at the Susquehanna Steam i
Electric Station, Units 1 and 2.
During the investigation, 10 de 5
reversing valve actuators in the auxiliary feedwater system have been 5
identified that will have voltage below the allowable limits for Z
proper operation (see Attachment 1).
Nonconformance Report (NCR)
D-00007 has been written on the Midland project as a result of this investigation to identify concerns and track the corrective action.
9 4
Ex s
5199c k
1 1
.\\
Bechtel Associates Professional Corporation I46321 MCAR 80 146370 Interim Neport 2 Page 2 All Class 1E 120 V ac electrohydraulic actuators have been reviewed
[ reference Calculation QPE-14(Q)], and the voltage drop has been calculated to be unacceptable for proper operation of 29 valves.
Nonconformance Report D-00008 has been initiated to document this l
nonconformance and track corrective action.
Analysis of Safety Implications the power cable voltage drop concerns associated with this MCAR have been determined to impact the safety of operations at the Midland plant.
Corrective Action The following corrective' actions have been or will be initiated.
- 1..A design calculation [QpE-18(Q)] has been issued to provide the requirements for sizing power cables for de reversing l
motor-operated valves (NOVs). All future Bechtel designs including rework will use these requirements for cable sizing.
I All design personnel in the Bechtel electrical group have been l
instructed regarding this requirement.
2.
A detailed review of Class 1E power and control circuits at the various plant voltage levels is being performed to confirm circuit adaquacy with regard to voltage drop. The scope of the review is provided in Attachment 2.
A schedule for.this review will be included in the next report.
As a result of this review, additional NCRs will be initiated as necessary to identify and track any nonconformances found, and appropriate corrective action will'be implemented to preclude recurrence.
All Class 1E de valve actuators have been reviewed [ reference Calculation QpE-18(Q)]. There are no' additional de valve actuators other than the 10 identified in the NCAR (see ).
3.
To correct the voltage condition for the de valve actuators, the power cables will be replaced with larger cables, and one of the starters will be relocated closer to the motor. This will reduce the voltage drop within acceptable limits as defined in Calculation _QPE-18(Q)..The new cable information has been issued for construction via Drawing 7220-E-158(Q), Rev 18, dated-March 7, 1984; Drawing Change Notice 3 to Drawing 7220-E-153(Q),
dated March 8, 1984; and Drawing Change Notice 10 to Drawing 7220-E-33(Q), dated March 21,11984'.
5199c
~ _
Bechtel Associates Professional Corporation 146321
= cia so i46370 Interim Report 2 Page 3 4.
Actions to be taken to correct the conditions on NCR D-00008 will be identified in a subsequent report.
Reportability This deficiency was reported to the NRC by Consumers Power Company as potentially reportable on January 6, 1984.
Submitted by:
M7 E.B. Poser \\
g g
p Project Engineering Manager M
Appr[ovedby:R.L. Castleberryf T
Electrical Chief Engineer I
/
Approved by:
i L'4-E.H. Smith Engineering Manager concurrence by:
farm.A.Dietrich/
Project Quality Assurance Engineer Attachments: 1.
List of DC Valve Actuators 2.
MCAR 80 Resolution Plan 5199c
Attcchment 1 to MCAR 80 Interin Raport 2 "8'
'^""^ " "8 l4632i Cable Number Local Control Cable Number Dist. Panel to Station Number Local Station To Valve Number Local Station (Starter)
Actuator Motor lh03177A IBD2114A INM03177A IBFWO81 R S, T, U IM03177B 1BD2115A INM03177B IBFWO82 R, S, T, U 2M03277A 2BD2114A 2NM03277A 2BFWO81 R, S. T, U 2M03277B 2BD2115A 2NM03277B 2DFWO82 R, S T U IM03865A 1AD1114A INM03865A 1AFWO82 AG H 1hJ3865B 1BD2116A INM03865B 1BFWO83 AG, H 2M03965A 2AD1114A 2NM03965A 2APWO82 AG, H 2M03965B 2BD2116A 2NM03965B 2BFWO83 AG, H IM03831 (ING05)
IBD2117A IC266 IBFWO88 AC, AF 2M03931 (2NG05) 2BD2117A 2C266 2BFWO88 AC, AF NOTES:
1.
IM03177A-2M03965B [E-158(Q)].re steam generator auxiliary feedwater isolation valves.
2.
IM03831-2M03931 [E-153(Q)] are auxiliary feedwater turbine 1/2005 stop valves.
5199c
~
p to MCAR 00 Interim Report 2
=
I46370 eage 1 of 3 l4632i
[
MCAa 80 ass 0 tut 10s etin I
[
Scope A detailed review of Class IE power and control circuits at the various plant 4
voltage levels will be performed using the following guidelines. This review is being performed to confirm the circuit adequacy with regard to voltage drop.
4 Medium Voltate_
r Cables at this voltage level are sized in accordance with the short circuit ampacities required. The criteria is well defined and documented in Bechtel 1
Calculation QPE-4(Q). A maximum voltage drop of 0.5% is allowed. A sample verification is to be made to confirm the adequacy of the cables using scheduled lengths.
=
Low-Voltage Power 1.
480 V Load Center Feeders The requirement for sizing these cables is in Bechtel Design Guide g
E-2.11.2.1, which allows a voltage drop of 1.5%.
A sample verification is a
to be made to confirm the adequacy with regard to voltage deep using scheduled lengths.
k 2.
460 V Motor Control Center Feeders i
The requirement for sizing these cables is in Calculation QPE-8(Q), which allows a voltage drop of 2.5%.
The motor-operated valves procured under F
Specification 7220-C-9 are capable of operating at 80% voltage.
Therefore, due to the additional margin available, no further verification I
is required. However, motors and power feeds to panels need to be checked i
to confirm the adequacy with regard to voltage drop using scheduled E
lengths.
j r
3.
Distribution Panel Feeders (120 V ac and 125 V de) h The panel feeds were originally designed based on the ampacity provided in y
calculation QPE-8(Q) and the voltage drop was determined by design engineering judr, ment.
?
Perform a detailed review to determine adequacy of cables with regard to I
=
voltage drop.
F 4.
125 V de Motor-Operated Valves
=
i A new calculation [ Calculation QPE-18(Q)] has been issued to establish the requirement using a 2.5% voltage drop.
r_
E L:
i 5199c b
N
I46370
- to MCAR 80 Intsela Raport 2 lggg Page 2 of 3 5.
120 V ac Electrohydraulic Valve Actuators Due to the permissive conts. cts used to operate these actuators, the need.
fer a special calculation was realized and as a result Calculation QPE-14(Q) ir being generated. The acceptability of existing configuration or rework if required will be identified upon finalization of this calculation.
Low-Voltare Control i
1.
120 V ac from Motor Control Transformers The requirement for sizing and limitations of use are contained in l
Calculation QPE-17(Q). Verification of all issued circuits was made when i
this calculation was finalized. Any new circuits issued since are checked j
for the total length as specified in Calculation QPE-17(Q).
j Note: Because revised data were obtained from the vendor in late 1983, l
this calculation is being revised. The net result is not espected to change the calculated data significantly. However, a review will be done upon finalization of the revised calculation.
2.
125 Y dc Control Guidelines and procedures will be established for review of such circuits and verification will be performed.
Exclusions The voltage drop requirements are well defined and appropriately implemented-at voltage levels of 460, 480, and 4,160 V.
Therefore, only verification of
-Channel 2A loads will be'made for these voltage levels.. If any discrepancies
{
are found, verification will be expanded to other channel loads as well.
I l
In addition, the following circuits will be excluded from the review and i:'
verification for the reasons stated.
i 1.--Motor-operated valves (NOVs) at the 460 V level are procured under Specification 7220-G-9.
This specification requires that these MOVs be capable of operating at 80% voltage at their terminals (i.e., allowance is i
made for 20% voltage drop). Bechtel calculation QPE-8(Q) provides
'j guidelines for sizing cables for a 2.5% voltage drop. Becaose an adequate margin is available between the requirement and the operating voltage limits of the NOVs..no review and/or verification is necessary. All MOVs shall have adequate voltage to operate within their stated limits.
'l 5199c
.~..
Attech2snt 2 to MCAR 80 I46370 Interim asport 2 Page 3 of 3 f 4 6 3 2 f
"*ro*p.All resistive loads will only provide less output (e.g., space
- d' ** '" ' *** ' "*** " * ** "*"'*"** ' " ' ***
d heaters or indicating lights) and will not render these components inoperative.
l 3.
The majority of the instrument circuits at Midland are low-current signals (i.e., 0-1 mA or 4-20 nA).
These circuits are not subject to voltage drop
(
concerns. In addition, the instruments in these circuits must be calibrated at the time of testing.
The majority of the current transformer circuits are used for indication and/or relaying purposes. All current transformer circuits are required to have a minimitm cable size of 10 AWG.
Therefore, these circuits need not be reviewed for voltage drop.
5199c
- _ _ _ _ - _ - _ _ _ _ _ _ _