ML14181A610
| ML14181A610 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 10/04/1994 |
| From: | Moore R, Shymlock M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML14181A607 | List: |
| References | |
| 50-261-94-24, NUDOCS 9410120091 | |
| Download: ML14181A610 (10) | |
See also: IR 05000261/1994024
Text
- plf REG&4
UNITED STATES
o
NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, N.W., SUITE 2900
ATLANTA, GEORGIA 30323-0199
.
Report No.: 50-261/94-24
Licensee:
Carolina Power and Light Company
P.O. Box 1551
Raleigh, NC, 27602
Docket No.:
50-261
License No.:
Facility Name: H. B. Robinson
Inspection Conducted:
September 12-16, 1994
Inspector:
_4
. Moore
Da e Si
Approved by:
_
_
_
_
_
_
_
_____
M. B. Shymfock, Chief
Date Signed
Plant Systems Section
Engineering Branch
Division of Reactor Safety
SUMMARY
Scope:
This routine, announced inspection was conducted to review the licensee's
status on the implementation of the Station Blackout (SBO) Rule and corrective
actions for previous inspection findings in the electrical area.
Results:
In the areas inspected two violations were identified. Violation 50-261/94
24-01 identified inadequate testing to demonstrate the one hour capability of
the Station Blackout (SBO) alternate AC power source (paragraph 2.8).
Non-cited violation 50-261/94-24-02 identified inadequate environmental
qualification documentation of LOCA-submerged safety related instrument cables
(paragraph 3.1).
The licensee's actions to comply with the SBO Rule were essentially complete,
with the exception noted above. The licensee's engineering organization
demonstrated a strong knowledge of electrical design issues in the areas
reviewed.
Enclosure
9410120091 941004
PDR ADOCK 05000261
Q
1.
Persons Contacted
Licensee Employees
- B. Barnett, Maintenance Support Manager
- J. Boska, Electrical, Instrumentation and Control Engineering Manager
- G. Castleberry, Electrical Design Manager
G. Chapel, Mechanical Design Engineer
- B. Clark, Maintenance Manager
D. Dyksterhouse, Civil Engineer
- D. Gudger, Regulatory Programs
- M. Herrel, Acting Plant General Manager
- R. Krich, Regulatory Affairs Manager
J. Lewis, Electrical Design Engineer
- F. Modlin, Electrical Design Engineer
R. Moore, Shift Operations Manager
- D. Neal, Licensed Operator Requalification Training Manager
- J. Pennington, Plant Operator
G. Walters, Support Training Manager
Other licensee employees contacted during this inspection included
engineers, technicians, and administrative personnel.
NRC Employees
- C. Ogle, Resident Inspector
- W. Orders, Senior Resident Inspector
- Attended exit interview
Acronyms and abbreviations are listed in paragraph 5 of this report.
2.0
Electrical Maintenance (62705) Station Blackout (SBO) Status
The inspector reviewed the status of Robinson activities to comply with
the SBO rule of 10 CFR 50.63, Loss of All Alternating Current Power.
The initial NRC Safety Evaluation (SE) was transmitted to the licensee
on February 4, 1991.
An NRC Supplemental Safety Evaluation (SSE),
transmitted to the licensee on September 16, 1991, addressed the
licensee's February 11, 1991 response to the SE. The licensee's
response to the SSE, dated October 21, 1991, stated that CP&L would
complete all items necessary to meet 10 CFR 50.63 requirements no later
than February 11, 1993. This inspection reviewed the status of the
10 CFR 50.63 requirements and specific Robinson requirements included in
2.1
Coping Strategy
The SBO coping strategy at Robinson included an eight hour coping
duration to maintain the plant at hot shutdown conditions using the
turbine driven auxiliary feed water pump and the steam generator power
operated relief valves. The unit would operate AC-independent for one
2
hour on the batteries. Power for the remaining seven hours of the
coping duration would be provided by the alternate AC (AAC) source which
was the Appendix R diesel generator. Starting of the AAC source and
alignment of the SBO loads was required to be accomplished within one
hour of determination of the SBO condition due to the limited battery
capacity. The following SBO loads were required to maintain the plant
at hot shutdown:
1.
Charging Pump A
2.
Service Water Pump D
3.
Component Cooling Water Pump A
4.
Motor Control Center (MCC)-5, which included Battery
Charger A
5.
Dedicated Shutdown Auxiliary Panel
2.2
AAC Source
The AAC source at Robinson was the Appendix R diesel generator which was
referred to as the dedicated shutdown diesel generator (DSDG). This was
classified in the SE as a minimally capable AAC power source design.
This design is not capable of powering all or any normal train of
safety-related shutdown equipment; but is capable of powering specific
equipment adequate for attaining safe shutdown during an SB0 in
conjunction with extensive operator actions both inside and outside of
the control room. The inspector noted that extensive manual operator
action was required outside the control room to start the AAC diesel
generator and align the necessary SBO equipment loads.
The DSDG was a General Motors Model EMD 20-645E4B, 20 cylinder diesel
engine coupled to a Beloit Type TBGZJ 2600 kW, 4160 VAC generator The
2600 kW capacity exceeded the SBO load requirement of approximately 1968
kW stated in Robinson NUS Report Number 8S19-P-100, AAC Power Criteria,
revision 4. The DSDG was independent of offsite and onsite emergency
power sources. The inspector concluded that the DSDG source met the
10 CFR 50.63 requirements for capacity and independence.
2.3
Modifications
There were two modifications related to SBO equipment. Modification
M-1129, Civil Compliance with SB0 Rule, upgraded SBO equipment and
structures to withstand wind forces based on criteria from the Uniform
Building Code. The upgrades were required on conduit supports,
electrical duct supports, the DSDG battery storage cabinet, and the 4.16
kV switchgear enclosure. Modification M-1081, Nitrogen Supply Backup to
Instrument Air, installed permanent one inch piping to connect the
nitrogen source to the PORVs. The inspector reviewed the modification
package and verified the field installation of these modifications and
concluded that the SBO related modifications had been completed.
2.4
Procedures
The inspector reviewed the licensee's operating procedures which
required revision to comply with the SBO rule. The following procedures
were revised to address operator actions during an SBO event:
- End Path Procedure EPP-1, Loss of All AC Power, revision 11
- EPP-22, Energizing Plant Equipment Using the DSDG, revision 7
- Abnormal Operating Procedure, AOP-017, Loss of Instrument Air,
revision 12
- Operating Procedure OP-402, Auxiliary Feedwater System,
revision 36
- PEP-355, Station Blackout Containment Isolation, revision 7
The procedures were appropriately revised to address SBO operator
actions.
Additionally, the inspector accompanied a non-licensed operator on a
walk-through of two SBO evolutions to verify the location and
accessibility of equipment and determine the operator's familiarity with
the evolutions. The evolutions were for PORV control with the nitrogen
backup supply for instrument air using AOP-017, and cross-connection of
the service water system to supply auxiliary feedwater using procedure
OP-402. The inspector concluded that the equipment was accessible and
that necessary tools and ladders were appropriately located to support
these evolutions. The operator was familiar with the procedures and the
evolutions.
2.5
Training
The inspector reviewed operator training documentation to determine if
SBO training had been accomplished. The following training plans and
simululator exercise guides were reviewed:
Procedures, EPP-1, EPP-21, EPP-22, dated December 13, 1993
EPP-23, Recovery From Loss of All AC, Restoration of Cooling Water
to Reactor Coolant Pumps, dated February 22, 1994
- RO/SRO Lesson Plant MDTA-LP-3, Mitigating Core Damage Loss of All
AC Power, dated July 27, 1988
dated June 10, 1994
4
dated April 11, 1994
date April 25, 1994
Additionally, the inspector reviewed the training rosters for 1993 and
1994, to determine if the operating shift crews had received the SBO
training. The inspector concluded that the SBO rule issues had been
incorporated into the operator training program and the operating shift
crews had been trained.
2.6
EDG Reliability Program
The licensee's Emergency Diesel Generator (EDG) reliability program was
implemented by Technical Management Manual Procedure, TMM-034, EDG
Reliability Program, revision 0. This procedure incorporated the
required elements specified in Regulatory Guide (RG) 1.155, Station
Blackout, dated August, 1988. The Robinson SBO EDG reliability of 0.95
and the appropriate failure trigger values were included in this
procedure. The current EDG reliability values exceeded the minimum 0.95
target value. The inspector concluded that the licensee had implemented
an EDG reliability program consistent with the RG 1.155 requirements.
2.7
Quality Assurance (QA) Program
The licensee's Plant Program Procedure PLP-018, QA Program for Non
Safety Related Systems and Equipment Used to Meet SBO Rule, revision 1,
implemented the QA program for the SBO equipment. The inspector
verified that the program elements specified in RG 1.155, Appendix A,
were incorporated into the licensee's QA program for SB0 equipment.
2.8
Testing
2.8.1 Test Requirement
The inspector reviewed the licensee's documentation to determine if
adequate testing had been accomplished to demonstrate the capability of
the AAC source. A primary element of the Robinson SBO coping strategy
was that the AAC source would be started and the required SBO equipment
aligned within one hour. The applicable regulation, 10 CFR 50.63,
requires that this capability, the time required for AAC source startup
and alignment to SB0 equipment, be demonstrated by a test. RG 1.155,
Appendix A, requires that a test program be implemented to ensure that
testing is performed to demonstrate conformance with system design and
readiness requirements, and that these tests be performed in accordance
with written test procedures. As discussed in the following paragraphs,
the licensee's test activity did not adequately demonstrate this primary
element of the Robinson SB0 coping strategy nor was the referenced test
activity performed in accordance with written test procedures.
2.8.2 Test Documentation
The licensee's documentation related to the test activity to demonstrate
the one hour capability of the AAC source was a memorandum from
D.B. Blakeney to File, dated February 1, 1993. This memorandum
described the performance of a simulator SBO event scenario in
conjunction with an in-plant walk-through of emergency procedure EPP-22
for energizing and loading of the AAC source. The simulator was manned
with a qualified operations shift crew and the procedure walk-through
was performed by a licensed operator. As described in the memorandum,
the DSDG was not started and the SBO equipment loads were not physically
aligned to the dedicated shutdown (DS) bus.
There was no written test
procedure. The emergency procedures were used for guidance in this
activity.
The memorandum stated that the process was discontinued to correct
procedure problems and the timed walk-through was restarted and
completed. Process milestones and their completion times were listed in
the memorandum and the total time was 49 minutes and 12 seconds.
Additional test documentation included surveillance test procedures,
OST-910, Biweekly Test of the DSDG, dated November 26, 1992, and
OST-911, Dedicated Shutdown Control Panel Test, dated November 27,1993.
The time required from start of the DSDG to closing of the DSDG output
breaker onto the DS bus was demonstrated by OST-910 test document to be
nine minutes. This did not support the 4 minute and 40 second time
period, for energizing the DS bus via the DSDG, stated in the
memorandum. The DSDG loading to 1970 kW during this test demonstrated
the capacity to supply the 1968 kW SBO load referenced in Robinson NUS
Report No. 8S19-P-100 although the SBO loads were not loaded. The DSDG
was loaded in parallel with the grid.
The OST-911 procedure, and modification documents M-445F and M-1004,
demonstrated that each of the SBO equipment loads have been connected to
the DS bus at some time in the past. These documents, however, did not
provide a demonstration that all the SBO loads were loaded onto the DS
bus simultaneously or indicate the time required for manual operator
actions to load any one load or group of loads. Therefore there was no
information to confirm the times stated in the memorandum for manual
operator actions.
2.8.3 Testing Conclusion
Based on the available documentation, the inspector concluded that the
licensee did not meet the requirements of 10 CFR 50.63 related to the
testing demonstration of the one hour capability of the AAC source for
startup and alignment of SBO equipment. The testing performed was
inadequate in that it did not establish the actual SBO configuration for
the AAC source and equipment and the test activity was not accomplished
in accordance with written test procedures. This item is identified as
Violation 50-261/94-24-01, Inadequate Testing of SBO Alternate AC Power
Source.
6
'
3.0
Follow-up on Previously Identified Inspection Findings (92701)
3.1
(Closed) Unresolved Item (URI) 50-261/89-26-02, Environmental
Qualification (EQ) of Submerged Cables
This item addressed the adequacy of the licensee's EQ files in
demonstrating the qualification of certain safety related cables to
withstand submergence conditions during a loss-of-coolant-accident
(LOCA).
The licensee became aware of the suspected unqualified
equipment in November, 1988, when it was identified that the containment
LOCA submergence level was potentially higher than the previously
accepted level.
The potentially unqualified equipment condition was
reported to the NRC in Licensee Event Report (LER) 88-22 in November,
1988. Supplement 1 to this LER was submitted in August, 1989.
The item was addressed in NRC Inspection Report 50-261/89-26 and
identified as unresolved pending the licensee providing documentation of
testing to verify the qualification of the cables. Subsequent
documentation provided to the licensee by the cable vendors was
submitted to the NRC in March 1992. This documentation was not adequate
to verify cable qualification as stated in an NRC safety evaluation
which was transmitted to the licensee on February 10, 1994. This URI is
closed based on the determination that the cables' qualification could
not be verified.
The lack of documentation to qualify these safety related cables is
identified as a violation of 10 CFR 50.49, EQ of Electrical Equipment
Important to Safety for Nuclear Power Plants. Section J of 10 CFR 50.49
requires that qualification documentation be maintained for the period
in which the covered item is installed in the plant. Upon the NRC
February 10, 1994, notification, that the available EQ documentation did
not verify the equipment qualification, the licensee initiated an
Engineering Evaluation (EE) to address operability related to this
equipment. EE 94-032, EQ Equipment Subject to Submergence, revision 0,
identified the 27 specific instrument cables subject to this condition
and determined that the safety function of the equipment could be
accomplished by other qualified equipment as an interim operability
determination until corrective actions were completed.
The licensee initiated corrective action to replace or upgrade the
cables to a tested and qualified configuration. A modification was
being developed during this inspection (Mod-M-1165) to replace or
upgrade the cables identified in EE 94-032. The modification
implementation was tentatively scheduled for the next refueling outage
which would be the first opportunity to perform this outage related
modification.
The inspector reviewed the licensee's identification and corrective
actions for this violation to determine if the NRC Enforcement Policy
criteria of 10 CFR Part 2, Appendix C, Section VII B for non-cited
violations (NCV) had been met. Based on the information discussed above
the inspector concluded that NCV criteria had been met. The violation
7
was identified by the licensee, it was not a violation which could have
been prevented by corrective actions for a finding in the previous two
years, corrective action will be accomplished in a reasonable length of
time, and the violation was not willful.
This item is identified as NCV
50-261/94-24-02, Inadequate EQ Documentation for Submerged Safety
Related Instrument Cables.
3.2
(Closed) URI 50-261/91-03-01, Evaluate LOCA/Submergence Test Results for
Qualification of Patel Conduit Seals
This item identified that the EQ file documentation for Patel Conduit
Seals did not adequately establish equipment qualification. The item
was unresolved pending additional testing of the Patel seals and
inclusion of the test documentation in the EQ files. This item was
reviewed in NRC Inspection Report No. 50-261/93-21 and a vender EQ test
report was provided. Engineering and Advanced Technology (EGS) report
EGS-TR-841215-08, Final Test Report for Qualification/Submergence
Retesting of Patel/EGS Conduit Seals, dated October 14, 1993, was
reviewed. The item remained open pending evaluation of the test by the
licensee and documentation of the test in the EQ files.
During this inspection the inspector verified that the licensee's retest
evaluation was adequate and the EQ File documentation was completed.
EQ Documentation Package (EQDP) 21.0, Patel Seals, revision 5, dated
February 28, 1994 incorporated the test information into the EQ files
and provided the licensee's test evaluation. This item is closed.
3.3
(Closed) IFI 50-261/91-21-03, E1/E2 Equipment Room Ambient Temperature
Conditions Not Evaluated
This item identified that ambient conditions in the safety-related
electrical equipment room had not been analyzed to determine the
potential impact on equipment if the non-safety ventilation was lost to
this space during a design base accident (DBA).
The licensee had
performed an analysis based on industry reference values for equipment
heat loads which produced results that were not consistent with informal
tested conditions. The licensee stated a formal test would be conducted
in 1992, to determine ambient conditions and the equipment would be
evaluated for these conditions.
The inspector reviewed the test document and the equipment evaluation
report. Special Procedure SP-1142, Area Temperature Measurements of the
E1/E2 Room for Determination of Internal Heat Gain, revision 0,
documented the test performance. The equipment evaluations were
documented in the E1/E2 50*C Equipment Evaluation Report, dated
July 20, 1994. The inspector concluded that the E1/E2 equipment room
ambient temperature DBA condition had been adequately evaluated. This
item is closed.
)
8
4.0
Exit Interview
The inspection scope and results were summarized on September 16, 1994,
with those individuals indicated in paragraph 1. The inspector
described the areas inspected and discussed in detail the inspection
findings listed below.
Licensee management provided a dissenting
comment regarding the SBO violation, stating their opinion that their
commitment to demonstrate the AAC power source capability was limited to
demonstration that the AAC power source could be started and connected
to the DS bus in one hour. They considered this commitment to be met by
the testing performed.
The EQ Cable Submergence finding was not identified as a violation at
the exit meeting. This finding was identified as a violation during
regional management review of inspection findings in the week following
the inspection. The licensee was informed of this violation by
telephone on September 26, 1994.
(Open) Violation 50-261/94-24-01, Inadequate Testing of SBO Alternate AC
Power Source
(Open) NCV 50-261/94-24-02, Inadequate EQ Documentation for Submerged
Safety-Related Instrument Cables,
(Closed) URI 50-261/89-26-02, EQ of Submerged Cables
(Closed) URI 50-261/91-03-01, Evaluate LOCA/Submerged Test Results for
Qualification of Patel Conduit Seals
(Closed) IFI 50-261/91-21-03, E1/E2 Equipment Room Ambient Temperature
Conditions Not Evaluated
5.0
Acronyms and Abbreviations
Alternating current
AAC
Alternate AC (source)
Abnormal Operating Procedure
Design Basis Accident
DS
Dedicated Shutdown
DSDG Dedicated Shutdown Diesel Generator
EE
Engineering Evaluation
Emergency Operating Procedure
Emergency Path Procedure
Environmental Qualification
kV
kiloVolts
kW
kiloWatts
LER
Licensee Event Report
LOCA Loss-of-Coolant-Accident
OP
Operating Procedure
OST
Operations Surveillance Test
mPEP
Plant Procedure
9
Power Operated Rel i ef Val ve
Quality Assurance
Regulatory Guide
Reactor Operator
Station blackout
Safety Evaluation
Supplemental Safety Evaluation
Senior Reactor Operator