IR 05000341/1986028
| ML20215C788 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 10/02/1986 |
| From: | Falevits Z, Muffett J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20215C749 | List: |
| References | |
| 50-341-86-28, NUDOCS 8610100440 | |
| Download: ML20215C788 (11) | |
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U.S. NUCLEAR REGULATORY COMMISSION
REGION III
-Report No. 50-341/86028(DRS)
Docket-No. 50-341 License No. NPF-43 Licensee: Detroit Edison Company 2000 Second Avenue Detroit, MI 48224 Facility Name:
Fermi 2 Nuclear Power Plant Inspection At:
Fermi 2 Site, Monroe, MI Inspection Conducted: August 7-22 and September 10, 1986 lo!2 Pl>
' Inspectors-Z. Falevits Date Approved By.
.'W.
Iluffett, Chief
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Plant Systems Section Date Inspection Summary Inspection on August 7-22 and September 10,1986 (Report No. 50-341/86028(DRS))
Areas Inspected: Special unannounced safety inspection conducted to followup on the fire event in an' electrical breaker and review the design of affected electrical components, licensee action on previous inspection findings, and design review of MOV control circuits (30703B, 92701B, 93702, and 92705B).
Results: Of the areas inspected, two violations were identified:
(1) Failure to adequately execute an inspection _ program - Paragraph 3.a; and (2) failure-to follow procedures - Paragraphs 3.b and 3.c.
861010o440 861002 gDR ADOCK 05000341 PDR
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DETAILS 1.
Persons Contacted R. S. Lenart, Plant Manager
- W. Miller, Supervisor Operational Assurance G. M. Trahey, Director Nuclear Quality Assurance (QA)
L. B. Collins, System Engineer F. Sandgeroth, Licensing Engineer J. P. Zoma, Principal Lead Engineer G. R. Overbeck, Superintendent Operations J. D. Leman, Superintendent Maintenance W. M. Tucker, Assistant Superintendent Operations R. W. McLeod, Acting Assistant Director Nuclear Training R. N. Haupt, Acting Lead I&C Engineer
- J. E. Conen, Licensing Engineer
'G. J. Carter, Plant Engineer J. S. Wiegand, Plant Engineer Failure Analysis Associated (FAA)
L. Swanger, Managing Engineer D. Mercaldi, Manager Engineer J. Vetter, Engineer L. Bisbee, Senior Engineer U. S. NRC
- W. Rogers, Senior Resident Inspector
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- M. Parker, Resident Inspector R. W. DeFayette, Regional Project Manager
- Denotes those in attendance of the exit meeting of September 10, 1986.
2.
Action on Previous Inspection Findings a.
(Closed) Open Item (341/85028-04):
This item concerned errors and discrepancies identified by the inspector during a review of the licensee's as-built program.
Field connections were found to be discrepant with the requirements of the design drawings.
-Discrepancies identified by the licensee were erroneously categorized by the licensee as unknown when they should have been classified as items needing corrective action and resolution.
A cable jacket inside a junction box was found to be cut and the cable was not labeled properly.
Subsequently, the licensee has issued the following documents to address the identified deficiencies:
(1) PN-21 No. 281303 dated June 5, 1985, and field completed June 12, 1985.
(2) PN-21 No. 281153 dated May 29, 1985 and field completed June 12, 1985.
(3) PN-21 No. 285159 dated August 8, 1985 and field completed August 26, 1985.
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-The inspector reviewed the licensee's corrective actions taken to resolve the identified deficiencies.
Corrective action was found to
.be adequate to close this item.
b.
(Closed) Open Item (341/85039-01):
During a previous inspection the inspector noted extensive chattering of LPCI loop selection logic relays E11-K35A/B and E11-K36A/B which are-located in the. relay room.
These relays are utilized to monitor.the differential
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pressure in the riser of the System Reactor Recirculation and are
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energized when Recirculation loop "A" riser differential pressure is greater than that of loop "B" by 0.627 psid (Reference Technical
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Specification table 3.3.3-2).
Subsequently the licensee contacted
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General Electric Company engineers who issued FDDR-1144, dated i
July 10,1985 to~ modify the LPCI circuitry.
The licensee issued EDP-4181, Revision 0 and A, and ECR-4181-1 to modify the circuitry by placing a contact in series with-the coil of the B31-K201 series relays
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from the B21-K202/K209 series relays (low water level /high drywell pressure). This action removes the voltage potential which caused the-relays to chatter while maintaining the design intent of the l
LPCI logic strings.
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The inspector reviewed EDP-4181 Revision 0 and A, and conducted a visual field inspection.
No chattering was noted by the LPCI logic
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relays E11-K35A/B and E11-K36A/B.
The licensee's actions in this area
are adequate to close this' item.
3.
Design Review of Eelectrical Systems Associated With the MCC Fire Event i
a.
On August 6, 1986, a fire at 260VDC MCC 2PB-1, Cubicle 4C, damaged
the electrical components and cabling associated with the power and controls to HPCI pump minimum flow bypass valve E4150F012. This valve is a normally closed four-(4) inch globe valve serving as
the shutoff valve for the HPCI pump minimum flow line to the suppression pool. This valve normally opens for the combination of
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high pressure and low flow in the HPCI~ pump discharge line.
Except for testing, this valve is not in use during normal plant operation.
Under accident conditions, this bypass valve will open whenever HPCI t
pressure exceeds 125 psig with flow less than 600 gpm.
This valve
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closes when the flow reaches 1,200 gpm.
During the fire at the MCC an electric overload and a fire alarm were received at the control
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room.
l (1) The licensee has hired an investigative team from Failure
Analysis Associated (FAA) to examine the cubicle that caught on fire and analyze each electrical component that failed or was
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burned during the event, and determine the root cause of the fire.
The inspector interviewed the FAA engineers and observed a portion of their investigation which was still in process.
I The inspector examined the burned cubicle and observed that most of the damage was near the contactors where auxiliary
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contact-assemblies completely melted.
Internal wiring-L
. insulation melted and the intensity of the fire appeared to have caused severe-damage to the internal components and to
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some external cables.
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-The inspector reviewed the design documents associated with valve E4150F012 to ascertain whether a design problem might have contributed:to the cause of the fire.
The following
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documents were reviewed:
Schematic Diagram'- 6I721-2221-7 Revision N dated
March 26, 1986.
-Front Elevation - 260V DC MCC 2PB-1 (DIV II) Drawing
SSD721-2530-14 Revision AA.
Logic diagram - Motor Operated Stop and Throttle
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Valves non-fail close Mode 6 Drawing 41721-2070-12, Revision A.
~ Interconnection Diagram - 260V DC MCC 2PB-1 (DIV II)
Drawing 6SD721-2522-12A, Revision C.
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D.C. MCC' internal diagram-reversing full voltage
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starter Drawing SSD721-2531-7, Revision D.
EDP-1424, Revision B, dated.0ctober 21, 1985.
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Procedure for walkdown of Motor Operated Valve Wiring
Verification dated August 16, 1986.
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DER for E4150F012 dated August 12, 1986 entitled
incorrect jumper installation - mov compartment.
- PN-21 No. 652161, dated October 11, 1985.
- Maintenance Instructions No. MI-E0043, Revision 1,
'(Motor Operated Valve Electrical Testing).
t-Deviation Event Report-No.86-041 dated August 6, 1986.
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Control Room Log, dated August 6, 1986.
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Sequence of Events Recorder log, dated August 6,1986.
- PN-21 No. 986436, dated November 29, 1985 (component level testing).
HPCI Mechanical Overspeed trip test-sequence of
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events SQE No. E4100-85-003.
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During the design review the inspector noted that prior to the fire the valve was cycled approximately 20 times in four hours.
The inspector verified that the control and power fuses were sized properly.
During the inspection it was verified that the control and power cables were not undersized and that the thermal overloads were of proper size.
The inspector determined that the reversing starter was sized properly and exercised within the hilowable duty cycle, that the design drawings agreed with each other and with the components installed in the field, and that modifications available for review which were done to the valve circuitry were properly designed and implemented.
(2) While reviewing PN-21 No. 652161 which implemented the requirements of EDP-1424, Revision B, to replace unqualified 250V DC limitorque motor operators utilizing electric motor brakes with those utilizing mechanical brakes which are environmentally qualified, the inspector noted that the Interim Alteration Checklist (IACL) denoted a jumper between termination points 10 and 34 on the valve limit switch wiring (Jumper No. 10).
In addition the Internal / External Jumper Log' enclosed in this PN21 indicated that a jumper existed between termination points 10 and 34.
The inspector reviewed the design schematic diagram Drawing 6I721-2221-7, Revision N, which did not show a jumper between point 10 in the opening circuit of the valve and point 34 which is part of the closing circuit of the valve. The inspector and the licensee performed a visual inspection of these circuits.
During this inspection, the inspector noted that Jumper No. 10 existed in the field between point 10 and 34.
The jumper between points 10 and 36 as required by the schematic diagram was omitted. The existing jumper between points 10 and 34 tied the closing and opening valve coils which created a condition in which a race existed between the two coils while trying to actuate the opening coil.
Further examination of the work package PN21 No. 652161, applicable procedures, inspection checklists, and testing requirements revealed that the jumper was installed in an -incorrect location.
The reviewer who performed the second check of the installed jumper used the Interim Alteration Checklist (IACL) rather than the design drawings to verify correct installation.
The individual transferred the information from the IACL (which was erroneous) to the Internal / External jumper log as a jumper from point 10 to point 34, and signed it as completed and verified, without actually using the design drawings.
The inspector noted that the PN-21 work package required verification of correct wiring as delineated on the design drawings; however, the instructions in the work package and in the applicable procedures were found to be very vague allowing for various interpretations and applications.
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s-No_ specific guidance was found as to how~and when procedure steps
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.are to be implemented. The wiring, checking and testing-functions'of the valve were open to individual. interpretation
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concerning the_ intent of the work request and applicable-
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procedures.
The inspector could not find a requirement for Q.C.
p verification of wiring configuration using the " yellow line"
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technique.'
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QJality Assurance requirements of EDP-1424, Item 7, Page 3
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states that,. !' Inspection and startup of electrical system shall be performed in accordance with station procedures and verifica-tion of all cable termination against the schematic diagram for
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the respective Limitorque motor operators." - This was not accom-plished with regard to Valve E4150F012 in that the inspector i
identified miswiring of internal jumpers.
In addition, during l
the' investigation for the root cause of this problem the
licensee noted that several days prior to the NRC's inspectors
finding,' a_ licensee's electrician identified another problem with
the external wiring of the same valve in that the "Brady" tags (wiring identification tags) on the Blue Conductor No. 4 and on the Green Black Conductor No. 9 were interchanged.
The Blue Conductor was terminated to point 36 instead of 7 as required
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by the drawing and the Green-Black Conductor was terminated to point 7 instead of 36 as required by the drawing, this changed
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the configuration of the control logic for.the opening cycle of the valve.
The electrician apparently reconnected the external connections to conform to the schematic diagram but engineering change documentation was not generated to record this change.
Because engineering change documentation was'not developed there
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was no engineering, QA or QC followup and review of these
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activities.
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(3) The following are several examples of specific. directions in l
which the instructions to verify internal wiring of the valve in question were not executed properly, either due to lack of specific _ instructions or due to inadequate inspections.
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(a) Attachment A, of PN-21 No. 652161 Item B.1 states, " Verify
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internal wiring of new M.0. Conforms with schematic 61-2221-7, Revision M., Contact MTC for resolution of any discrepancies with engineering."
(b) Attachment A of PN-21 No. 652161, Item A.1 states, "All
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determs/reterms to be in accordance with Interim I
Alteration Checklist (12.000.80)."
i (c) Maintenance Inspection Checklist (MIC) No. 85-4493, Page 1 requires a QA witness point and states, " Verify all motor
reterms per the IACL...."
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(d) Motor Operated Valve Electrical Testing Inspection and Test sheet, Procedure MI-E0043 Step 7.6 states, " Verify all electrical wiring is conect" (note that this step was signed as verified for the valve in question).
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(e) Motor Operated Valve Electrical Testing Inspection and Test-sheet, procedure MI-E0043 Step 7.14 states, " Verify torque switch bypass limit, if applicable, ensure proper valve operation" (This step was also signed as verified).
(f)
D.C. Motor Data, Procedure MI-E0048 Step 7.3 states, " Post Maintenance Inspection, Testing and Restoration complete."
This step-was signed as verified.
(g) Maintenance Inspection Checklist (MIC) No.-855235 required Q.A. witness point and states, "Q.C. to verify reterm of any disconnected wiring per IACL." This step was signed as verified.
The inspector discussed the above with licensee personnel assigned to the task force team investigating this issue and stated his concerns. It appears to the inspector that instructions given to verify the internal wiring are vague and not specific as to what documents should be used and generated. The present procedures do not contain requirements for QC verification of wiring configuration (Q.C. yellow-lining).
Procedure steps are not always in logical order and the intent of the. steps is not always clear.
The inspector also discussed additional training of personnel to perform these check and tests in a uniform standardized way.
(4) Subsequent to the findings of the miswiring of Valve E4150F012, the licensee formed a special task force to review and determine the root cause of the problem and establish a corrective action program.
The licensee performed an additional walkdown to determine if any deviations exist in wiring in the motor-operated valves modified or. refurbished as part of outage 85-01.
A total of 13 valves were inspected six in the RHR system (Ell),
two in the LPCS System (E21), and five in the HPCI system (E41).
The inspector. examined a number of valves (E4150F006 and E1150F028A) which were selected for' inspection by the licensee.
The inspection ~of the 13 valves by the licensee did not' reveal any additional miswired valves.
The licensee has developed a proposed corrective action plan to prevent recurrence, this'.
plan is documented in DER-86-051. The proposed corrective action plan requires that the IACL be revised to include both the determ and reterm columns for all installations.
It also contains a requirement that training be given in use of the IACL, that the use of conductor colors be used in lieu of "Brady" tag identification and that the EDP Procedure NE 3.9 be modified to clearly prescribe where Q.C. yellow-line verification (wiring confiruration check) is to be performed.
In regards to testing, the licensee's proposed corrective action plan includes revision of maintenance procedures to prohibit the changing of post maintenance testing requirements without concurrence of the applicable engineering group. The applicable engineering group
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will provide additional guidance as to when and how procedure steps are to be implemented and how the verification is to be accomplished.
The licensee's proposed corrective action included QC verification of the wiring configuration. The Q.C.
inspectors will employ the Lead Design Document during their verification' activities.
Additional long term corrective actions are also under consideration by the licensed.
Based on the findings discussed above, the inspector informed the licensee that failure to effectively execute its program for inspection of activities affecting quality to verify conformance with the documented instructions, procedures, and drawings for accomplishing the activity, is a violation contrary to the requirements of 10 CFR 50, Appendix B, Criterion X (341/86028-01(DRS)).
b.
During the fire event the licensee noted that the control circuit configuration for RCIC Steam Line Inboard Isolation Valve E5150-F007 as depicted on Drawing 61721-2231-3, Revision K, will stop the valve at 95% closed using limit switch LS-16.in the closing circuit rather than the Torque Switch as required by the FSAR for isolation valves.
The licensee has conducted additional design reviews and has identified three additional valves with similar circuit configuration.
The valves were E11-F028A and B, (Suppression Pool Spray Isolation Valves) and E51-F008, (RCIC Outboard Isolation Valve).
These valves were designed to close either on 100% close limit switch signal or on torque switch signal.
These valves are required by the FSAR to close on torque switch
signal only.
The licensee installed temporary jumpers to modify the circuitry of these valves to close on torque switch actuation.
The inspector reviewed the following accuments associated with the temporary modifications:
MI-M049 - Maintenance instructions and designated Pom
Procedure.
- POM 12.000.15 - Testing requirements for work order
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PN-21574164.
MI-E005 Revision 3, Maintenance instructions for MCC's.
- Temporary Modification No. 86-0106 - Pom 12.000.25.
- Maintenance Inspection Checklist No. 86-1532..
PN21 No. 574164.
- New Cable Terminations Procedure No. 38.000.09, Revision 4.
Schematic Diagram 61721-2095-30, Revision K.
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Schematic Diagram 61721-2205-2, Revision 0.
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Schematic-Diagram 61721-2205-03, Revision J.
- Schematic Diagram 6I721-2201-25, Revision H.
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. Schematic Diagram 6I721-2095-29, Revision I.
- The engineering design included in the temporary modification packages appeared to be adequate.
The_ prescribed activities appeared to be comprehensive and thorough; however, during a field visual inspection of. Valve E5150-F007.the. inspector noted
.that the-licensee had recently added a jumper between points 14 and 19. A Temporary Modification Tag No.86-103 was attached to the Jumper.
Deco Temporary Modification Procedure No. 12.000.25, Revision 7, Paragraph 7.2.4.3 states that the person installing the. temporary modification will:
" Tag the temporary modification as close as practical to-the actual modification and include the following information on each tag:
(a) a brief description; (b) the installers name; (c) the date installed."
Contrary to the above requirements, Tag No.86-103' contained (1) the wrong description (480V.MCC72F-4A cubicle 50,~instead
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of 480V.MCC 72F-4A, cubicle 40); (2) name of installer was missing; (3) date of installation was missing.
Based on the findings outlined above the inspector informed the licensee thai. failure to follow procedures is an example of a violation of Technical Specification'Section 6.8.1 (341/86028-02A(DRS)).
c.
During the review of the work packages associated with the licensee's reinspections conducted on the 13 selected motor operated valves as discussed in paragraph 3.a.(4) of this report, it was determine that Engineering Change Requests (ECR) were not written on the 13 valves during the period of November, 1985, when the operators were replaced and valve internals rewired.
Replacement Procedure of EDP-1424, Revision A, Item No. 7, Page 1, states " Verify that the internal limitorque wiring conforms with the latest schematic diagram.
Should the internal wiring not conform to tif schematicachangepapermustbewrittentomodifytheoperator internal wiring.
Contrary to the above, the licensee had not produced the required change paper (modification documentation) for the operators on the 13 valves.
The wiring-of the 13 valve operators had been modified by adding or removing jumpers to conform to the design drawings.
The IACL which is not regarded as a modification documentation (change paper),.therefore it is not processed through the engineering review cycle.
Normally used to record the addition of jumpers.
The engineering review cycle is used to record and evaluated the addition of jumpers.
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-The inspector informed the licensee that failure to ' follow
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. instructions and procedures is an example of a violation of Technical Specification Section 6.8.1 (341/86028-02B(DRS)).
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-4.
Review of Undersized Cables (DER-0216)
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The : inspector reviewed DER-0216 dated May 23, 1986, which addressed-undersized cables.
As part of the reconciliation of design
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calculations DC 2117 and DC 3188 the licensee found that the Full Load i '
Amperage-(FLA) of Cables 209045-1P, 209055-1P, 209065-2P, 209075-2P and
'212821A-1P exceeded the maximum allowable values of the amperage for the.
o cable sizes for the existing tray fill and the ambient temperatures.
Licensee review of this-issue raised the question of the validity of a
formula used=to determine the size of these cables. This formula (DC 2117)-
has been empirically derived by a DECO engineer:and tested only for a limited number of cables.
The licensee determined that this' formula could not be used in all cases and-therefore decided to revise (DC 2117) to
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remove this formula. The five cables noted above were replaced with-larger
size cables in July 1986, using EDP-5789 to perform the change and tests required.
No additional safety related cables have.been sized using this
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formula. _ Some 80P cables might have been sized using this formula.
These a
l cables are presently being reviewed by the licensee.
Based on the review oof licensee corrective actions this matter is considered resolved.
i 5.
Review of DECO Valve Circuit Design Control The inspector conducted a design review to determine whether licensee design drawings conform to the design requirements as they are delineated on the General Electric (GE) Elementary Diagrams and Functional Control Diagrams.
Review of selected drawings in the RCIC (E51) and the RHR (Ell) systems indicated that DECO has deviated
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from the'(GE) standard operating mode for the control circuits
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associated with motor operator valves.
The inspector reviewed the
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following:
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RCIC (E51) System
G.E. Elementary Diagram 791E421TG, Sheet No. 2,
Revision 20.
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G.E. Elementary Diagram 791E421TG, Sheet No. 7A,
j Revision 20.
l Deco Drawing 61721-2231-3, Revision K.
Drawing (a) above indicates on the typical detail for AC motor l-operated. valve and control circuit that TS-18 and LS5 are permanently bypassed.
Deco drawing (c) does not contain this bypass. Also limit switch configuration on drawing (a) for the valve control utilizes a'different limit switch arrangement than the ones used on
the Deco circuit of the valves for this system. Drawing (b) indicated y.
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points J-43 and J-51 as same point electrically; however, on DECO drawing (c) these two points have been separated (J51 going through LS-16 and TS-17 while J-41 only through TS-17). Similar conditions exist with circuits of other valves and other NSSS systems.
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On August 26, 1986, the licensee arranged a telephone conference between G.E. engineers, Deco engineers and the NRC.
The inspector raised the concern that it appears that control circuits of NSSS valves have been modified by the licensee without the written approval and formal review of the G.E. engineers and that might have been one of the root causes of the recent licensees findings of isolation Valve E51-F007 closing on 95% limit switch signal rather than on 100% torque switch signal and Valves E11-F028A and B and E51-F008 closing on either limit switch or torque switch rather than on torque switch only.
The licensee inoicated that they will request G.E. to assure that reviews have been conducted on all valve circuits that deviate from the G.E. design intent and that changes to the design has being controlled through G.E.-FDI's and FDDR's. This item is considered open pending licensee and G.E. action and NRC review (341/86028-04(DRS)).
5.
Open Items Open items are matters which have been discussed with the licensee, which will be reviewed further by the inspector, and which involve some action on the part of the NRC or licensee or both.
An open item disclosed during the inspection is discussed in Paragraph 4.
6.
Exit Interview The inspectors conducted a telephone conference with the licensee representatives at the conclusion of the inspection on September 10, 1986, and summarized the scope and findings of the inspection.
The licensee acknowledged the statements made by the inspectors.
The inspectors also discussed the likely informational content of the inspection report with regard to documents reviewed by the inspector during the inspection.
The licensee did not identify any such documents as proprietary.
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