IR 05000155/1993020
| ML20059M347 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 11/10/1993 |
| From: | Darrin Butler, Gardner R, Winter R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20059M336 | List: |
| References | |
| 50-155-93-20, NUDOCS 9311190043 | |
| Download: ML20059M347 (6) | |
Text
_
_
- _.
i
.
.
I
U. S. NUCLEAR REGULATORY COMMISSION
.
-
REGION III
Report.No. 50-155/93020(DRS)
Docket No. 50-155 License No. DPR-6 l
Licensee: Consumers Power Company
'
1945 West Parnell Road
,1 Jackson, MI 49201
- 1 Facility Name
- Big Rock Point Nuclear Plant
,
"
j Inspection At: Big Rock Point Site, Charlevoix, MI
- f. -
Inspection Conducted: October 25 through 29, 1993
-
It /lo /93 Inspectors:.
,
D. Butler Date G. W plok3 R. Winter Date
~
.
Approved By:
.b-II!10!d
'
R. N. Gardner, Chief Date t
Plant Systems Section
'
Inspection Summary Inspection on October 25-29. 1993 (Recort No. 50-155/93020(DRS))
'
Areas Insoected: Announced followup inspection of previously identified EDSFI findings in accordance with Temporary Instruction (TI) 2515/111.
Results:
The inspection determined that the licensee made good progress in resolving EDSFI issues. EDSFI followup item closure packages were thorough and complete. Nine previously identified findings were closed (Section 2.0).
One inspection followup item was identified regarding the lack of EDG suction heater design information and understanding how the heater test circuit
'
functioned (Section 3.0).
!
.
.
A
.
,
l
=l
'
.
9311190043 931110 PDR ADOCK 05000155 G
PDR ll
.
-
--
--
.
'
DETAILS i
1.0 Principal Persons Contacted Consumers Power Company
'
- P. Donnelly, Plant Manager
- J. Boss, Engineering Manager
- J. Tilton, Senior Engineer
- S. Beachum, Special Projects Supervisor,
- G. Withrow, Safety and Licensing Director
,
- H. Bourassa, Senior Licensing Engineer
- E.-Evans,.Engin'eering Supervisor
-
-m
'
'
?.
- D. Turner, Maintenance Ma6ager-
.
.
+
~"
- D. Hughes, Executive Engineer""-
- t
-
,
U. S. Nuclear Reculatory Commission (NRC)
{
- C. Brown, Resident Inspector
{
-
- R. Gardner, Chief, Plant Systems Section
- Denotes those present during the exit meeting on October 29, 1993.
'
2.0 Licensee Action on Previously Identified Insoection Findinos
.
a.
(Closed) Open Item (155/92019-01): A calculation did not exist to demonstrate that the 46kV line (second offsite power source) could
,
maintain adequate voltage levels during a design basis accident (DBA)
'
with the 2.4kV voltage regulator out of service.
The licensee performed calculation No. EA-ELEC-VOLT-012, Revision 0,
" Big Rock-Minimum Station Power Bus Voltage Levels when Fed from 46kV System and 2400V Voltage Regulator wt of Service " The inspectors verified that the calculation adequately modeled the 46kV system with the 2.4kV voltage regulator in bypass. The calculation concluded that the 46kV line would provide adequate voltage during this condition.
This item is considered closed.
b.
(Closed) Violation (155/92019-03): The diesel fire pump fuel oil was not sampled in accordance with the frequency specified in Technical
,
Specification (TS) 4.7.11.1.1.C.
The Chemistry Department changed their method of scheduling quarterly surveillances. The Chemical Laboratory Status Sheet now-identifies the actual sampling date rather than listing the month the sample was last taken. This was acceptable to the inspectors.
,
This item is considered closed.
'
c.
(Closed) Open Ites (155/92019-04):, The low level alarm for the EDG fuel e
oil tank was set well below the Technical Specification (TS) required
'
level of fuel; however, the licensee relied on daily rounds to
- i
-
,
- * " *
- S
~
.
- * _
,
- cqp
administratively control fuel oil level above TS. The licensee stated that the low level alarm was set at 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> of fuel and was considered a gross failure alarm. Contracts were established with local fuel oil distributors to obtain fuel onsite within several hours.
The licensee measures EDG fuel oil level using a gauge and/or a dipstick and records the information on the Fuel Oil Report sheet.
Fuel ordering criteria was added to the Fuel Oil Report that will ensure a minimum 8 day supply is maintained. The EDG fuel oil level is administratively maintained in excess of the TS requirement (> 3 day supply). This -item is considered closed.
d.
(Closed) Deviation (155/92019-05): The original emergency diesel generator (EDG) room ventilation calculation used an incorrect **>" * *
-
j conversion factor. As a result, the instalJed exhaust fan was one-half
,
thesizenecessar)toprovideadequateventilation.
The inspectors reviewed calculation No. EA-RFI-CG-34-01, Revision 0, " Emergency Diesel Generator (EDG) Room Re-evaluation for Exhaust Fan Sizing." The calculation determined the EDG room air flow requirement was 2909 CFM. The licensee replaced the original fan with one that had a 3710 CFM air flow capacity. This item is considered closed.
e.
(Closed) Unresolved Item (155/92019-06A): A calculation did not exist to demoristrate that the cooling water pump had sufficient net positive suction head (NPSH). The licensee performed calculation EA-EDSFI-C0C-8-02 during the EDSFI inspection. The calculation concluded that under certain lake level and suction water temperature combinations, the NPSH may not be met. The EDSFI team did'not identify any past lake level and water temperature combinations which would have affected EDG operability.
The licensee issued Operations Memo No. 07-92, " Big Rock Point Plant - Emergency Diesel Generator Operability.".The memo instructed the operators to administratively declare the EDG inoperable if the lake level drops below 578 feet elevation.
Temperature was not pbrceived as a concern since lake temperature typically does not exceed 75 F versus 100'F used in the calculation.
In addition, the licensee recently modified the EDG cooling water suction screen and installed a new suction line check valve which further increased the available NPSH. This item is considered closed.
f.
(Closed) Unresolved Item (155/92019-068): The EDG cooling water suction pressure testing criteria (s 21 INHG) was set too high.
.
Following suction line improvements, the licensee performed calculation No. EA-SC-92-026-02, Revision 0, "EDG Cooling Water e
Pump Net Positive Suction Head Requirements," and incorporated the s
new acceptance criteria (s 14 INHG) in surveillance procedure No.
T7-28, Revision 20, " Emergency Diesel Generator Auto Test Start."
-
!
,
.
b
&
I
.
..,,.
,
,
.
a j
i,
!
The inspectors verified the calculation adequately modeled the EDG i
cooling water suction pressure. The calculated pressure was J
13.85 INHG and is reasonably close to the measured suction
pressure of 13 INHG. This item is considered closed.
g.
(Closed) Unresolved Item (155/92019-06C): EDG suction screen cleaning was being postponed even after suction pres:;ures indicated potential
,
'
screen plugging.
The licensee added a caution note to surveillance procedure No.
T7-28 Revision 20. The note stated, in part, that "a suction j
pressure Iqual to 13.5 INHG, may be an indication that the suction
strainer was beginning to plug. 'Haintenance action to clean the strainer must be given a HIGH priority to assure the EDG will
";
.
'
operate properly." The inspectors discussed screen cleaning
-
i
,
prioritization with engineering, operations and maintenance, and
!
concluded the departments were sensitive to this issue.
In 4;
addition, the licensee has replaced the old suction screen (designed with slits) with a right cylinder stamped metal screen having 1/4" diameter holes. The new screen should not be as prone to plugging as the old screen. This item is considered closed.
h.
(Closed) Open Item (155/92019-07): Wiring discrepancies existed between the electrical design drawings and the as-built configuration of the EDG
!
control panels. Design drawings did not show redundant jumpers found during the EDSFI walkdowns.
l The licensee removed these jumpers from the affected EDG control
'
panel circuits and tested the circuits to verify proper operation.
The EDG control panels now reflect the as-built configuration of the plant. This item is considered closed.
i.
(Closed) Open Item (155/92019-08): Analyses identified a number of overfilled conduits that had the potential to be thennally overloaded.
,
-
The licensee identified several cable trays and conduits that
l exceeded the National Electric Code (NEC) recommended percent fill. The NEC recommended fill is based on the assumption that all cables in the tray are fully loaded. Since the majority of
.
these cables were not loaded td full amperage capacity, the cables would not require derating. The licensee has developed a cable fill engineering specification which should prevent overfill concerns in the future. This item is considered closed.
,
!
j.
(Closed) Open Item (155/92019-09): Design information was not available to determine if installed fuses were properly selected and sized.
~~
The licensee developed an Electrical Scheme Fuse Index. The-
"
!
majority of fuses have been walked down and the remaining ones will be verified during future walkdowns. During NRC walkdowns, the inspectors verified fuses listed in the Index and identified
several fuses that were not listed. The licensee indicated they
.
'
,
'Y I
-
.;
- ---
-_
--
..
.
-.
. - - -
.
.
- -
_ ___
s would add these omissions to the Index. The licensee has
proceduralized fuse control guidelines to replace with a like-for-
'
like fuse. Parameters considered in the like-for-like replacement include the same type, physical size, voltage and current rating.
If the correct fuse is unavailable, the engineering department will determine a suitable replacement for continued plant operation and document the irregular substitution. This item is-considered closed.
!
k.
(Closed) Violation (155/92019-10): Facility Change (FC) No. 670,
" Modify EDG Circuit with Time Delay Overcurrent Relays," did not,,
-
identify any' post; modification test (PMT) requirements for relays "T"
-
and "CR5" to verify relay actuation.
-. w-p r
.
T During the EDSFI,;the411censef retested the modification and I
verified relay Nos. "T" (trouble relay) and "CR5" (auxiliary relay) operated satisfactorily. The licensee strengthened PMT requirements in administrative procedure Nos. 3.1.1.1, " Facility
.
Changes" and 3.1.1.2, " Equipment Specification Changes." The procedures now require functional test results be fully documented and include provisions to ensure all portions of the modification have been tested.
In addition, a Post Modification Test Matrix was developed. The matrix identifies standard electrical and mechanical components and the type of PMT that should be performed. The inspectors reviewed the PMT requirements for Specification Change (SC) No.93-002, "EDG Ventilation Fan
-
Replacement," and concluded the SC was adequately tested. This item is considered closed.
3.0 Enoineerino and'T chnical Suonort ~
~
The EDSFI closure packages were thorough and complete..The inspectors noted that items identified as weaknesses in the EDSFI report had been addressed and recent calculations were of good quality. Two modification packages were reviewed and walked down. The packages were adequately implemented.
During plant walkdowns, the inspectors questioned how the EDG cooling water suction heater operated and how heater operability was verified. The electric heating element is described in Final Safety Hazard Report (FSHR), Section 9.5.7, as being used when freezing weather was a possibility and periodically checked for circuit reliability. The heater circuit is turned on during the performance of procedure No. 0-VAS-1, Revision 10 " Cold / Warm Weather Checklists. " Operation's personnel check circuit continuity once per shift by depressing a push button and verifying the test light comes on. The inspectors further questioned the licensee on how the test circuit was wired.
The licensee could not produce any circuit drawings and were unsure how the test circuit operated. The system description described the circuit as a 250 watt, 240 volt heating element. The 10L lighting panel appeared to supply power to the heater through breaker Nos.14 and 16.
!
To verify the test lamp response, the licensee individually opened each
~
breaker and pressed the push button. However, the test lamp would light when
_..
4
.
hf
,b
.
S'
..
>
~ ~
'b
.SMi
,
~
-.,.....
_
_
.
.
either breaker was opened. The breakers were not ganged together; therefore, the potential existed for a valid test indication to occur without the heater operating at 100% efficiency.
Even though the licensee considered the suction heater to be nonsafety (not required to function during or following a DBA), the heater is important for.
EDG availability during severe winter weather. The inspectors considered the lack of heater circuit design information an engineering weakness. This is
considered an inspection followup item (155/93020-Ol(DRS)).
l The licensee infomed the inspectors that they were. implementing a systems engineer program. The inspectors reviewed administrative, procedure No.
3.1.12, Revision 0, " System Engineering Group Organization and
'
_.,
Responsibility." General requirements, included ownership of thersystem'and
. 6 y~ ;
achieving high performance standards. 'A _ team concept was also being
'
established for safety and important nonsafety systems. Each week, a " roving" engineer is stationed in the plant to act as a liaison between maintenance / operations and engineering. The inspectors viewed this program as a positive step in identifying such items as the EDG suction heater design deficiency and ensuring that operations is receiving information that properly indicates equipment status.
4.0 Inspection Followup Items Inspection followup items are matters which have been discussed with the licensee, which will be reviewed further by the team, and which involve some action on the part of NRC or licensee or both. One followup item disclosed during the inspection is discussed in Section 3.0.
5.0 Exit Interview The inspectors conducted an exit meeting on October 29, 1993, at the Big Rock Point Plant to discuss the major areas reviewed during the inspection and the inspection findings. NRC personnel and licensee representatives who attended this meeting are documented in Section 1.0 of this report. The licensee did not identify any documents or processes as proprietary.
.
'
-
j
.
.
'
~~