ML14181A978
| ML14181A978 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 02/02/1998 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML14181A977 | List: |
| References | |
| 50-261-97-14, NUDOCS 9802090232 | |
| Download: ML14181A978 (15) | |
See also: IR 05000261/1997014
Text
U.S. NUCLEAR REGULATORY COMMISSION
REGION II
Docket Nos:
50-261
License Nos:
Report No:
50-261/97-14
Licensee:
Carolina Power & Light (CP&L)
Facility:
H. B. Robinson Unit 2
Location:
3581 West Entrance Road
Hartsville, SC 29550
Dates:
November 23 - January 3, 1998
Inspectors:
B. Desai, Senior Resident Inspector
J. Zeiler, Resident Inspector
Approved by:
M. Shymlock, Chief, Projects Branch 4
Division of Reactor Projects
9802090232 980202
ADOCK 05000261
G
EXECUTIVE SUMMARY
H. B. Robinson Power Plant, Unit 2
NRC Inspection Report 50-261/97-14
This integrated inspection included aspects of licensee operations,
maintenance, engineering, and plant support. The report covers a six-week
period of resident inspection.
Operations
The conduct of operations was professional and safety-conscious
(Section 01.1).
The inspector identified that the licensee had erroneously included the
wrong heatup and cooldown limit curves during the implementation of
improved TS. The licensee determined that these errors were caused by
inattention to detail. The potential safety implications were minimal
due to plant.procedures specifically prescribing the correct heatup and
cooldown limits (Section 01.2).
The inspector concluded that the licensee appropriately performed an
investigation of a problem related to secondary side oscillations
experienced earlier in the report period. Actions taken by the licensee
have contributed to the reduction of oscillations in recent weeks
(Section 01.3).
The licensee promptly and adequately implemented and planned corrective
actions to return the "A"
Emergency Diesel Generator to operable status
following inadvertent wetting of equipment due to inappropriate valve
lineup on the service water system (Section 02.1).
The onsite review functions of the Plant Nuclear Safety Committee (PNSC)
were conducted in accordance with Technical Specification (TS). The
PNSC meetings were well coordinated and meeting topics were thoroughly
discussed and evaluated. Nuclear Assurance Section (NAS) continued to
provide strong oversight of licensee activities (Section 07.1).
Maintenance
In general, routine maintenance activities were performed satisfactorily
(Section M1.1).
The inspector concluded that a weakness in the post maintenance testing
and planning existed, which necessitated a reentry in a TS action
statement. However, the licensee identified several problems with post
maintenance and surveillance testing that could place the unit in
TS 3.0.3. They stopped these test until the conditions could be
evaluated. An IFI was identified, pending licensee evaluation involving
Residual Heat Removal (RHR) Emergency Core Cooling System (ECCS)
flowpath operability with valve FCV-605 open (Section M1.2).
2
Engineering
The inspector concluded that overall, engineering support was effective
in maintaining safe operations of the plant (Section E1.1).
Plant Support
The inspectors concluded that radiation control and security practices
were proper (Section R1.1 and S1.1).
Report Details
Summary of Plant Status
The unit operated at rated power for the entire report period.
I. Operations
01
Conduct of Operations
01.1 General Comments (71707)
The inspectors conducted frequent control room tours to verify proper
staffing, operator attentiveness and communications, and adherence to
approved procedures. The inspectors attended daily operation turnovers,
management reviews, and plan-of-the-day meetings to maintain awareness
of overall plant operations. Operator logs were reviewed to verify
operational safety and compliance with Technical Specification (TS).
Instrumentation, computer indications, and safety system lineups were
periodically reviewed from the Control Room to assess operability.
Frequent plant tours were conducted to observe equipment status and
housekeeping. Condition Reports (CRs) were routinely reviewed to assure
that potential safety concerns and equipment problems were reported and
resolved.
In general, the conduct of operations was professional and safety
conscious; specific events and noteworthy observations are detailed in
the sections below.
01.2 Technical Specification Reviews
a. Inspection Scope (71707)
The inspector reviewed licensee compliance with TS, including periodic
surveillance requirements, Limiting Conditions for Operations, and
Bases.
b. Observations and Findings
During a review of TS, the inspector noted discrepancies in the Reactor
Coolant System (RCS) Heatup and Cooldown limit curves (Figures 3.4.3-1
and 3.4.3-2 of TS 3.4, Reactor Coolant System). The heatup curve
(Figure 3.4.3-1) contained the same curve as the cooldown curve in
(Figure 3.4.3-2). The inspector notified the licensee of the
discrepancy. The licensee initiated a condition report to determine the
cause and corrective action. The licensee determined that the heatup
and cooldown curves associated with the original improved TS submittal
to the NRC were correct. However, during a later submittal of the same
curves to the NRC, the licensee mistakenly included the heatup curve for
the cooldown curve. The NRC subsequently issued the improved TS with
the curves submitted by the licensee. Then, during the licensee copying
of the NRC issued improved TS for distribution, an addition error was
2
made when the cooldown curve was copied for the heatup curve. Thus, the
controlled TS copies that were distributed were incorrect.
The licensee immediately initiated actions to correct the problem. This
included, change out of the page associated with the heatup curve to
incorporate the correct curve. The cooldown curve was technically
correct however, it was not the one submitted for approval by the NRC.
The licensee discussed theissue with Nuclear Reactor Regulation (NRR).
Current NRR plans to reissue the cooldown curve as an administrative
change. Additionally, the licensee issued a night order to make the
operating staff aware of the condition.
The inspector reviewed plant operating procedures that control
evolutions involving RCS heatup and cooldown. General Procedure
(GP)-002, Cold Shutdown to Hot Subcritical at No Load Tavg and GP-007,
Plant Cooldown from Hot Shutdown to Cold Shutdown, refer to the TS
heatup and cooldown limit curves in the precautions section. However,
the implementing section of the procedure specifically prescribed the
numeric valve limits. The inspector determined that while the
precautions were in error by virtue of reference to the wrong curves in
TS, the body of the procedure prescribed the correct heatup and cooldown
valves. Thus, adherence to procedures GP-002 and GP-007 would not have
led to exceeding cooldown or heatup limits. Additionally, since the
implementation of the improved TS. the plant has not had to perform any
evolution requiring RCS heatup or cooldown.
Conclusions
The inspector identified that the licensee had erroneously included the
wrong heatup and cooldown limit curves during the implementation of
improved TS. The licensee determined that these errors were most likely
caused by inattention to detail.
The potential safety implications were
minimal due to plant procedures specifically prescribing the correct
heatup and cooldown limits.
01.3 Secondary Plant Oscillations
a. Inspection Scope (71707)
The inspector monitored licensee response to secondary plant
oscillations that occurred during the report period.
b. Observations and Findings
The unit periodically experienced oscillations on the secondary side,
including unexpected changes in the heater drain tank level. These
oscillations also affected the feedwater system, resulting in the
receipt of low feedwater pressure alarms and swings in the feedwater
flow control valves, and oscillations in steam generator levels. Though
3
these oscillations were minor in nature, the licensee initiated an
investigation of the potential cause(s) of the oscillations.
During this investigation, the licensee determined that the oscillations
were most likely initiated due to a problem with Level Control Valve
(LCV) 1-530 A. This valve regulates flow through the heater drain tank
pumps to maintain the correct heater drain tank levels. The licensee
was postulating a problem internal to the valve, or with the control
system associated with the valve. As part of the investigiation, the
licensee opened (approximately five turns) the bypass valve to LCV
1530 A. This has reduced the occurrence of oscillations. The licensee
plans to troubleshoot the valve internals as well as control circuitry
during the upcoming refueling outage.
c. Conclusions
The inspector concluded that the licensee appropriately performed an
investigation into the problem related to secondary side oscillations
experienced earlier in the report period. Actions taken by the licensee
have contributed to the reduction of oscillations in recent weeks.
02
Operational Status of Facilities and Equipment
0.2.1 Water Intrusion into Emergency Diesel Generator "A"
Electrical
Components
a. Inspection Scope (71707)
The inspector reviewed the circumstances involving the "A"
EDG being
declared inoperable following the intrusion of leaking water from the
service water system into the generator control panel,.current
transformer cabinet, and air compressor control circuitry. The water
drained from the ventilation ducts located in the EDG room ceiling
following an operator's failure to conduct a proper valve lineup. The
inspector discussed the incident with operations, maintenance, and
engineering personnel, and reviewed procedures related to the
configuration control of cooling water systems isolated for cold weather
protection.
b. Observations and Findings
On December 28, 1997, the Inside Auxiliary Operator (IAO) was assigned
to support chemistry personnel in aligning service water cooling flow to
the "C"
Auxiliary Boiler Sample Cooler. Service water to the sample
cooler, as well as other non-essential service water cooling loads, such.
as the Evaporative Air Coolers (EACs), had previously been isolated and
the piping drained/vented to prevent freezing in accordance with
Operating Procedure (OP)-925, Cold Weather Operation. During the
alignment of cooling water to the sample cooler, the IAO opened valves
admitting service water to the EACs. The IAO failed to realize that the
4
EAC vent/drain valves located in the EDG Ventilation Fan rooms, directly
above the EDG rooms, were still open per OP-925. This allowed service
water to flow out of the open vent valves, onto the floor of the fan
rooms, and into the EDG ventilation duct which opened into the ceiling
of the EDG rooms. Water entering the EDG room got on several EDG
electrical components including the generator control panel, current
transformer cabinet, and air -compressor. The control room was alerted
to the problem after receiving several alarms, including,-a fire
protection panel FDAP B-1 trouble, vital battery charger trouble, and
air compressor trouble/trip. Upon investigation, the operators
discovered the source of the water and isolated the valves. The "A"
was declared out-of-service at 8:59 a.m., requiring entry into a seven
day action statement per TS 3.8.1.B. Recovery actions were developed to
inspect, repair, and return the EDG to an operable status.
The inspector reviewed the extent of the impact from the water intrusion
and the licensee's recovery activities. The licensee inspected all
areas that were wetted. Moisture was found on the generator buss bars
and current transformers. These areas were dried with portable heaters
and the current transformers meggered to verify proper performance. The
air compressor was allowed to.dry and visually verified to operate
properly following re-energization. The EDG ventilation ductwork was
also dried and inspected for any damage. Inspection of the "B"
EDG room
revealed that no water had reached this area. Following all inspections
and repairs, the EDG was operated to verify operability, and was
returned to service at 2:45 a.m. on December 29, 1998. The inspector
determined that the licensee had adequately inspected and taken actions
to restore the equipment to a reliable condition.
The inspector reviewed CR 97-2508 which documented the licensee's
investigation of the incident. The CR identified several deficiencies
in the actions taken by the IAO during the alignment of service water to
the sample cooler. While the IAO had been authorized at the pre-shift
briefing that morning to align sample cooling water to the boiler, he
had not consulted with his supervisor when he determined that there was
no actual procedure specifically designed to accomplish this task. The
IAO also had not reviewed OP-925 to understand how service water had
been isolated to the EACs for cold weather protection. As a result. he
did not realize that there were open vents/drains in the EAC lineup that
needed to be closed prior to aligning service water to the sample
cooler. The licensee determined that this incident could have been
prevented had proper procedure usage and self-checking been performed.
The licensee's corrective actions for this incident included the
following: 1) guidance was sent to each shift to review existing
procedure usage guidelines, reinforcing the expectations that approved
procedures be utilized where appropriate, 2) a modification was
initiated to provide an alternate source of cooling water to the
auxiliary heating system, and, 3) formal operator training was to be
developed and implemented to address weaknesses in the operator
5
understanding of system configurations associated with the cold weather
protection lineup, EAC cooling water lineup, and alternate cooling to
the auxiliary heating system. The licensee also planned to revise OP 925 to provide greater controls, e.g., caution/clearance tagging, of
systems temporarily aligned for cold weather protection in order to
heighten operator awareness of the configurations.
As a result of this and several other recent operator errors, operations
management identified a negative trend in operator human performance
errors. The licensee plans to conduct stand-down meetings with each
operations shift. At these stand-down meetings, the Shift
Superintendent of Operations plans to discuss the declining trend in
human performance, the specific human performance errors identified
recently, and emphasize.the need to ensure clear communication and
understanding of task assignment details, proper self-checking
techniques, and the use of three way communications, etc.
c. Conclusions
The inspector concluded that the licensee had promptly implemented
adequate recovery actions to return EDG "A"
to an operable status
following the intrusion of service water into EDG electrical components.
The root cause of the incident was attributed to weak procedural usage,
understanding of the cold weather protection, and service water
alignment to out-of-service equipment. The licensee promptly and
adequately implemented and planned corrective actions to return the A
EDG to operable status following inadvertent wetting of equipment due to
inappropriate valve lineup on the service water system.
07
Quality Assurance In Operations
07.1 Plant Nuclear Safety Committee and Nuclear Assessment Section Oversight
a. Inspection Scope (40500)
The inspector evaluated certain activities of the Plant Nuclear Safety
Committee (PNSC) and Nuclear Assessment Section (NAS) to determine
whether the onsite review functions were conducted in accordance with TS
and other regulatory requirements.
b. Observations and Findings
The inspector periodically attended PNSC meetings during the report
period. The presentations were thorough and the presenters readily
responded to all questions. The committee members asked probing
questions and were well prepared. The committee members displayed a
good understanding of the issues and their potential risks. Further,
the inspector reviewed NAS audits and concluded that they were
appropriately focused to identify and enhance safety.
6
c. Conclusions
The inspector concluded that the onsite review functions of the PNSC
were conducted in accordance with TS. The PNSC meetings attended by the
inspector were well coordinated a.nd meetings topics were thoroughly
discussed and evaluated. NAS continued to provide strong oversight of
licensee activities.
08
Miscellaneous Operations Issues (71707)
08.1
(Closed) Licensee Event Report (LER) 50-261/97-10. Emergency Diesel
Generator(EDG) Inoperability Due to Mispositioned Output Breaker Control
Switch:
This LER was issued by the licensee on September 15, 1997.
following the identification of a mispositioned B EDG output breaker
control switch. In this condition, the breaker was not available to
supply power to the associated emergency bus. While the exact time of
mispositioning was not determined, the B EDG was thus determined to be
inoperable at least for a period of approximately four days. The NRC
issued a Severity Level III violation on December 12, 1997 (EA 97-490)
as a result of this issue. Items EEI 50-261/97-10-02 and 50-261/97-10
03 associated with this issue remain open, pending NRC review of
licensee corrective actions as a result of the violation. Based on
this, the LER is closed.
08.2 (Closed) LER 50-261/97-11, Reactor Trip Due to Condensate Pump "B"
Shaft
Failure:
This LER was submitted by the licensee on December 16, 1997
following a reactor trip from 100 percent power on November 16. 1997.
The circumstances related to the reactor trip were discussed in NRC
inspection report 50-261/97-11, dated November 7, 1997. The inspector
reviewed completed and planned corrective actions related to the reactor
trip. Based on satisfactory assessment of licensee actions, this LER is
closed.
II. Maintenance
M1
Conduct of Maintenance
M1.1 General Comments
a. Inspection Scope (61726 and 62707)
The inspector reviewed/observed all or portions of the following
maintenance related-work requests/job orders (WRs/JOs) and/or
surveillances and reviewed the associated documentation:
OST 910 Dedicated Diesel Generator Monthly
Engineering Surveillance Test (EST)-146, End-of-Life Moderator
Temperature Coefficient Measurement,
7
Maintenance Surveillance Test (MST)-014, Steam Generator Pressure
Protection Channel Testing.
WR/JO 97-ACPD1, Replacement of Hagan Modules in Steam Generator
Pressure Protection Circuitry,
WR/JO AAOU-002, Limitorque Grease Inspection of Containment Fan
Cooler Service Water Valve V6-33E.
b. Observations and Findings
The inspector observed that these activities were performed by personnel
who were experienced and knowledgeable of their assigned tasks.
Procedures were present at the work location and being followed.
Procedures provided sufficient detail and guidance for the intended
activities. Activities were properly authorized and coordinated with
operations prior to starting. Test and maintenance equipment in use was
properly calibrated, procedure prerequisites were met, and system
restoration was completed. Since the performance of surveillance EST
146 was considered to be an infrequent activity, a detailed pre-job
briefing, which included management oversight and coordination, was
provided. Good three-way communication was observed between maintenance
personnel during the performance of MST-014. Maintenance personnel
performing safeguards system Hagan module replacement activities
associated with WR/JO 97-ACPD1 were very experienced and knowledgeable
of the system and were deliberate in their actions. Operations
management provided guidance on the proper implementation of Improved
Technical Specifications during Hagan module replacements via a detailed
Night Order.
c. Conclusions
The inspector concluded that routine and preventative maintenance
activities observed, as well as surveillances, were performed
satisfactorily.
M1.2 Planning of Post Maintenance Testing
a. Inspection Scope (62707)
The inspector reviewed circumstances surrounding a corrective
maintenance activity on air operated valves HCV-758 and FCV-605. on the
Residual Heat Removal(RHR) System.
b. Observations and Finding
The licensee conducted planned maintenance on RHR valves FCV-605 and
HCV-758. These valves are required by TS 3.5.2.B to be maintained
closed with the motive air isolated.
The maintenance conducted on these valves involved motive air regulator
filter replacement. Following filter replacement. the air regulator
8
setpoint check was not initially performed as part of post maintenance
testing (PMT). due to poor communication between shifts as well as poor
planning. This required reentry in TS 3.5.2.B to accomplish that PMT
requirement.
Further, it was not initially recognized that another PMT requirement
involving valve stroking would potentially place the unit in TS 3.0.3.
Therefore, the PMT involving valve stroking was not performed pending
resolution of issue involving TS 3.0.3 entry. A CR was initiated by the
licensee to evaluate the circumstances leading to this situation as well
as resolve the TS 3.0.3 applicability. Since the above valves are not
allowed to be opened in Modes 1, 2. and 3, the PMT involving valve
stroking was postponed until the next available opportunity (upcoming
refueling outage).
During the CR evaluation, the licensee also recognized that Operations
Surveillance Test (OST) Procedures OST-251-1, RHR Pump "A" and
Components Test, and OST-251-2, RHR Pump "B"
and Components Test
requires the opening of valve FCV-605 to accomplish RHR pump discharge
check valve testing under circumstances where a sufficient differential
pressure across tested check valves cannot be obtained under normal
circumstances. However, the OSTs did not recognize that opening valve
FCV-605 potentially places the unit in T.S 3.0.3. The licensee plans to
evaluate the OSTs prior to their next required performance. Pending
licensee completion of the review associated with this issue, it will be
classified as Inspector Followup Item (IFI) 97-14-01. Opening of RHR
Valves FCV-605 or HCV-758 During Testing.
The inspector discussed the issue with the licensee and verified that
appropriate controls were in place to preclude inadvertent opening of
valves HCV-758 and FCV-605, pending resolution of the issue.
c. Conclusion
The inspector concluded that a weakness in the post maintenance testing
and planning existed, which necessitated a reentry in a TS action
statement. However, the licensee identified several problems with post
maintenance and surveillance testing that could place the Unit in
TS 3.0.3. They stopped these test until the conditions could be
evaluated. An IFI was identified, pending licensee evaluation involving
.RHR ECCS flowpath operability with valve FCV-605 open.
9
M8
Miscellaneous Maintenance Issues (92902)
M8.1 (CLOSED) Unresolved Item (URI) 50-261/96-06-03, Review Licensee
Assessment of Need to Supplement Licensee Event Report (LER) 50-261/95
001-00: LER 50-261/95-001-00 involved the licensee's identification that
ASME Section XI Inservice Testing of Safety Injection (SI) valves,
potentially rendered the SI system inoperable as a result of the test
configuration. The LER indicated that an evaluation had been initiated
to determine conclusively whether the SI system had been inoperable in
the testing configuration. The licensee completed their evaluation in
April 1995, at which time it was confirmed that the system had been
inoperable. During a previous inspection, the inspector reviewed the
LER, subsequent licensee evaluation and corrective actions. Non-Cited
Violation 50-261/97-06-02 was issued for inadequate test procedures
which allowed the adverse test configuration.
During review of the LER, licensee evaluation results, and corrective
actions in the previous inspection, the inspector noted that the
licensee had failed to provide a supplement to the LER describing the
results of the April 1995 evaluation and corrective actions. The
inspector believed that the LER had not provided complete information
regarding the cause of the condition or corrective action. As a result
of the inspector's comments, the licensee initiated CR 97-01045 to
evaluate whether a supplement was warranted.
On January 8. 1998. the licensee submitted LER 50-261/95-001-01, which
provided the results of the aforementioned April 1995 evaluation and
subsequent corrective actions. The inspector reviewed the LER and
determined that the licensee had provided adequate details regarding the
resolution of this issue. Based on review of LER 50-261/95-001-01, this
URI is closed.
M8.2 (Closed) LER 50-261/95-001-01, Safety Injection Pump Testing Requires TS 3.0 Entry: As discussed in Section M8.1 of this report, the licensee
supplied this LER supplement to provide additional information regarding
the results of an evaluation to determine conclusively whether the SI
system had been inoperable in certain ASME Section XI Inservice test
configurations, as well as the corrective actions to address the
incident. Based on review of the licensee's evaluation results and.
corrective action, this LER is closed.
III. Engineering
El
Conduct of Engineering
E1.1 General Comments (37551)
The inspector periodically assessed engineering support of activities
affecting plant operations and maintenance. The inspector concluded
10
that overall, engineering support was effective in maintaining safe
operations of the plant.
IV.
Plant Support
R1
Radiological Protection and Chemistry Controls
R1.1 General Comments (71750)
The inspector periodically toured the Radiological Control Area (RCA)
during the inspection period. Radiological control practices were
observed and discussed with radiological control personnel including RCA
entry and exit, survey postings, locked high radiation areas, and
radiological area material conditions. The inspector concluded that
radiation control practices were proper.
Si
Conduct of Security and Safeguards Activities
S1.1 General Comments (71750)
During the period, the inspector toured the protected area and noted
that the perimeter fence was intact and not compromised by erosion nor
disrepair. Isolation zones were maintained on both sides of the barrier
and were free of objects which could shield or conceal an individual.
The inspector periodically observed personnel, packages, and vehicles
entering the protected area and verified that necessary searches,
visitor escorting, and special purpose detectors were used as applicable
prior to entry. Lighting of the perimeter and of the protected area was
acceptable and met illumination requirements.
V. Management Meetings
X1
Exit Meeting Summary
The inspectors presented the inspection results to members of licensee
management at the conclusion of the inspection on January 16, 1998. No
proprietary information was identified.
- ieneePARTIAL
LIST OF PERSONS CONTACTED
Li censee
J. Boska. Manager. Operations
H. Chernoff, Supervisor. Licensing/Regulatory Programs
T. Cleary. Manager, Maintenance
J. Clements. Manager, Site Support Services
J. Keenan, Vice President, Robinson Nuclear Plant
R. Duncan, Manager, Robinson Engineering Support Services
R. Moore, Manager. Outage Management
J. Moyer, Manager, Robinson Plant
R. Warden, Manager, Nuclear Assessment Section
T. Wilkerson, Manager, Regulatory Affairs
D. Young, Director. Site Operations
NRC
B. Desai, Senior Resident Inspector
J. Zeiler, Resident Inspector
12
INSPECTION PROCEDURES USED
IP 37551:
Onsite Engineering
IP 40500:
Effectiveness of Licensee Controls in Identifying. Resolving, and
Preventing Problems
IP 61726:
Surveillance Observations
IP 62707:
Maintenance Observation
IP 71707:
Plant Operations
IP 71750:
Plant Support Activities
IP 92902:
Followup - Maintenance
ITEMS OPENED, CLOSED, AND DISCUSSED
Opened
Type Item Number
Status
Description and Reference
IFI
50-261/97-14-01
Open
Opening of RHR Valves FCV-605 and HCV-758
During Testing (Section M1.2)
Closed
Oype
Item Number
Status
Description and Reference
LER
50-261/97-10
Closed
Emergency Diesel Generator(EDG)
Inoperability Due to Mispositioned Output
Breaker Control Switch (Section 08.1)
LER
50-261/97-11
Closed
Reactor Trip Due to Condensate Pump "B"
Shaft Failure (Section 08.2)
50-261/96-06-03
Closed
Review Licensee Assessment of Need to
Supplement Licensee Event Report (LER) 50
261/95-001-00 (Section M8.1)
LER
50-261/95-001-01 Closed
Safety Injection Pump Testing Requires TS 3.0 Entry (Section M8.2)
Discussed
Type Item Number
Status
Description and Reference
NONE
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