ML14178A231
| ML14178A231 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 06/01/1992 |
| From: | Garner L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML14178A229 | List: |
| References | |
| 50-261-92-11, NUDOCS 9206230109 | |
| Download: ML14178A231 (13) | |
See also: IR 05000261/1992011
Text
6V REGO
UNITED STATES
o
NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, N.W.
ATLANTA, GEORGIA 30323
Report No.:
50-261/92-11
Licensee: Carolina Power and Light Company
P. 0. Box 1551
Raleigh, NC 27602
Docket No.:
50-261
License No.: DPR-23
Facility Name: H. B. Robinson
Inspection Conducted: April 11, 1992 - May 10, 1992
Lead Inspector:
-
0./
-z
L. W. Garner, Sr. Residt
spector
Date Signed
Accompanying Personnel:
C. R. Ogle, Resident Inspector
Approved by: /
C7
A. 0. Christensen, Section Chief
Da e Signed
Division of Reactor Projects
SUMMARY
Scope:
This routine, announced inspection was conducted in the areas of
operational safety verification, response to events, surveillance
observation, maintenance observation, and modifications.
Results:
A violation was identified for failure to inhibit the north cable
vault fire suppression system prior to performing hot work in the
area. The actuation of the fire suppression system resulted in a
declaration of an Alert due to a toxic gas release within the
protected area. The event resulted from an established work
practice involving signing a section of the hot work permit which
indicated that the fire system had been inhibited before actually
doing so (paragraph 3).
A violation was identified for failure to follow instructions, in
that, service water system valves were removed before they were
scheduled. This resulted in the operating portion of the service
water system being in a configuration which had not been
seismically evaluated (paragraph 5).
9206230109 920601
PDR ADOCK 05000261
Q
2
A violation was identified for failure to correctly translate a
Residual Heat Removal system design basis into modification
instructions (paragraph 6).
An unresolved item was identified involving strainers being
installed in the component cooling water (CCW) pumps' suction
piping (paragraph 5).
An inspector followup item was identified involving proposed
control circuit modifications to allow both channels of the
emergency bus undervoltage load shed logic to trip the C CCW pump
(paragraph 4).
The emergency response to the unusual event and alert
declarations of April 13 and 15, respectively, were good
(paragraph 3).
The licensee demonstrated sensitivity to shutdown risk by
securing all work in and around areas associated with the safety
buses' normal offsite power source when both emergency diesel
generators became inoperable (paragraph 3).
Actions to preclude inadvertent removal of core components during
the upper internals package removal were well planned and
implemented (paragraph 3).
REPORT DETAILS
Persons Contacted
- R. Barnett, Manager, Outages and Modifications
C. Baucom, Senior Specialist, Regulatory Compliance
J. Benjamin, Shift Outage Manager, Outages and Modifications
- R. Beverage, Manager, Quality Assurance
W. Biggs, Manager, Nuclear Engineering Department Site Unit
- S. Billings, Technical Aide, Regulatory Compliance
- R. Chambers, Plant General Manager, Robinson Nuclear Project
T. Cleary, Manager -
Balance of Plant Systems and Reactor
Engineering, Technical Support
- D. Crook, Senior Specialist, Regulatory Compliance
- J. Curley, Manager -
Robinson Engineering Support, Nuclear
Engineering Department
- C. Dietz, Vice President, Robinson Nuclear Project
- D. Dixon, Manager, Control and Administration
- J. Dobbs, Manager, Nuclear Assessment Department Site Unit
- W. Flanagan, Manager, Operations
- W. Gainey, Manager, Plant Support
B. Harward, Manager - Mechanical Systems, Technical Support
P. Jenny, Manager, Emergency Preparedness
D. Knight, Shift Supervisor, Operations
- R. Labelle, Project Engineer, Nuclear Assessment Department
Site Unit
A. McCauley, Manager -
Electrical Systems, Technical Support
R. Moore, Shift Supervisor, Operations
- P. Musser, Manager -
Engineering Assessment, Nuclear
Assessment Department Site Unit
D. Nelson, Shift Outage Manager, Outages and Modifications
A. Padgett, Manager, Environmental and Radiation Control
- M. Page, Manager, Technical Support
D. Seagle, Shift Supervisor, Operations
- E. Shoemaker, Project Engineer, Operations
- R. Smith, Manager, Maintenance
- D. Stadler, Onsite Licensing Engineer, Nuclear Licensing
G. Walters, Operating Event Followup Coordinator, Regulatory
Compliance
D. Winters, Shift Supervisor, Operations
Other licensee employees contacted included technicians,
operators, engineers, mechanics, security force members, and
office personnel.
H. Christensen, Section Chief, Division of Reactor Projects,
was onsite April 14, 15, and 16, 1992, to meet with the
resident inspectors and plant management. Mr. Christensen
along with the inspectors observed the emergency prepared
ness response to the April 15 Alert (see paragraph 3).
- Attended exit interview on May 13, 1992.
2
Acronyms and initialisms used throughout this report are
listed in the last paragraph.
2. Plant Status
RO 14 continued during the report period with fuel reload
scheduled for the third week of May. The core was fully off
loaded on April 22, 1992, to allow work on the CCW and RHR
systems, as well as to minimize shutdown risk. An NOUE
occurred when both EDGs became inoperable on April 13 and an
Alert was declared on April 15, when carbon dioxide gas was
released in a vital area (see paragraph 3).
At the end of
the report period, preparations were in progress to support
fuel reload.
3.
Operational Safety Verification (71707)
The inspectors evaluated licensee activities to confirm that
the facility was being operated safely and in conformance
with regulatory requirements. These activities were
confirmed by direct observation, facility tours, interviews
and discussions with licensee personnel and management,
verification of safety system status, and review of facility
records.
To verify equipment operability and compliance with TS, the
inspectors reviewed shift logs, Operations' records, data
sheets, instrument traces, and records of equipment
malfunctions. Through work observations and discussions
with Operations staff members, the inspectors verified the
staff was knowledgeable of plant conditions, adhered to
procedures and applicable administrative controls, and were
aware of inoperable equipment status.
Shift changes were
observed, verifying that system status continuity was
maintained and that proper control room staffing existed.
Plant tours and perimeter walkdowns were conducted to verify
equipment operability, assess the general condition of plant
equipment, and to verify that radiological controls, fire
protection controls, physical protection controls, and
equipment tagging procedures were properly implemented.
Upper Internals Package Removal
On April 20, 1992, the inspectors witnessed the upper
internals package removal. Lighting and visibility in the
refuel cavity was good. In addition to personnel visually
observing the removal, a camera was utilized to look under
the upper internals package as soon as it was lifted above
the vessel flange. The inspectors concluded that the
actions to preclude inadvertent removal of core components
had been well planned and implemented.
3
NOUE Declaration Due To EDG Inoperability
On April 13, at approximately 10:00 a. m., the B EDG was
secured during routine surveillance testing because the
fitting downstream of the engine driven fuel oil pump showed
increased fuel oil leakage. At the time the B EDG was
considered to be available for service (TS do not require
any EDGs to be operable during cold shutdown).
The A EDG
was not available for service since it was partially
disassembled for PM work activities. Plant management,
after considering shutdown risk, decided to remove the B EDG
from service to repair the fitting. The inspectors verified
that appropriate considerations and actions were taken to
ensure that the remaining power sources, normal offsite
power and the dedicated shutdown DG were and would continue
to be available. These actions included securing all work
activities in the switchyard and around critical electrical
distribution components. At 1:43 p.m. when the B EDG was
placed under clearance, the plant entered a NOUE declaration
in accordance with its emergency plan (i.e., loss of both
EDGs).
The inspectors witnessed replacement of the fitting
and the subsequent successful fuel oil line leak test.
After verifying that the B EDG would start and run without
additional difficulties, the B EDG was considered to be
available for service. The routine testing was completed
later the same day. The inspectors verified by direct
observations, record reviews, and personnel interviews that
the emergency preparedness plan (including notifications)
had been implemented as required.
Alert Declaration Due To Carbon Dioxide Release Inside Vital
Area
On April 15, 1992, at 12:23 p.m., fire detection system zone
9 actuated releasing carbon dioxide fire suppressant into
the north cable vault area. Personnel evacuated the area
and fire brigade members were on the scene within one to two
minutes. The alarm and actuation were determined to be
spurious (i.e., there was no evidence of a fire).
At
approximately 12:30 p.m., fire brigade members in SCBA
initiated oxygen concentration measurements. At 12:42 p.m.,
the control room was informed that oxygen concentrations as
low as 12 percent had been found. After evaluation of the
EALs, an Alert declaration was issued at 12:53 p.m., based
upon a toxic gas release inside a vital area. The approved
emergency procedures classified gases which can create an
oxygen deficient atmosphere (such as carbon dioxide) as
toxic gases. Actions were taken to ventilate the affected
area to the plant stack. At 1:28 p.m., oxygen measurements
in the north cable spread area indicated normal air
concentrations. At 1:56 p.m., a final oxygen concentration
survey was completed in adjacent and lower elevations of
4
containment and the auxiliary building. This survey also
confirmed oxygen concentrations were normal and there were
no pockets of carbon dioxide trapped in low areas. Since
turnover to the TSC was in progress at the time, it was
decided to complete this process and allow the TSC to review
the plant conditions and actions taken. The TSC was fully
staffed and turnover from the control room was completed at
2:06 p.m. Based upon a review of the plant conditions, the
SEC in the TSC declared the Alert condition terminated and
the event over at 2:11 p.m. The inspectors verified by
direct observation, record reviews, and personnel interviews
that the emergency preparedness plan had been properly
implemented during this event.
ACR 92-103 was issued to review the spurious actuation cause
and develop corrective actions. The inspectors interviewed
personnel involved in the event and reviewed applicable
records and the draft ACR conclusions. The ACR indicated,
and the inspectors confirmed, that the event had occurred
due to a long standing work practice (over 11 years) of
authorizing hot work permits prior to defeating the fire
detection or suppression systems. In this specific
instance, the fire technician had signed and dated the hot
work permit no.92-247, FP-005 attachment 7.1 section III
item 3, before inhibiting the fire suppression system for
zone 9. Item 3 states "Hot Work Permit approved, system(s)
inhibited (if applicable), ready for shift foreman's
approval."
The fire technician had identified on the hot
work permit that the fire suppression system for zone 9
would need to be inhibited. The person receiving the permit
was unaware that he was to contact the fire technician prior
to beginning work so that the fire technician would inhibit
the zone 9 fire suppression system. Thus, when grinding
activities for M-1074, Electrical Penetration Replacement
Project -
Phase II, began at 12:41 p.m., the system had not
been inhibited. This work practice had apparently existed
as a method to expedite work activities by already having
the authorized hot work permit at the location when the fire
detection or suppression system was inhibited. The
circumstances surrounding this event was of concern because
of the long duration involved and that individuals in
Operations outside the fire protection group should have
been aware of the practice. The failure to inhibit the zone
9 fire suppression system was identified as a VIO: Failure
To Implement FP-005 Resulted In Alert Declaration,
92-11-01.
One violation was identified. Except as noted above, this
program area was adequately implemented.
5
4.
Monthly Surveillance Observation (61726)
The inspectors observed certain safety-related surveillance
activities on systems and components to ascertain that these
activities were conducted in accordance with license
requirements. For the surveillance test procedures listed
below, the inspectors determined that precautions and LCOs
were adhered to, the required administrative approvals and
tagouts were obtained prior to test initiation, testing was
accomplished by qualified personnel in accordance with an
approved test procedure, test instrumentation was properly
calibrated, the tests were completed at the required
frequency, and that the tests conformed to TS requirements.
Upon test completion, the inspectors verified the recorded
test data was complete, accurate, and met TS requirements,
test discrepancies were properly documented and rectified,
and that the systems were properly returned to service.
Specifically, the inspectors witnessed/reviewed portions of
the following test activities:
OST-401
Emergency Diesels (Slow Speed Start)
Safety Injection System Flow Test
Bus Undervoltage And Load Shed Test For
Emergency Bus El
Bus Undervoltage And Load Shed Test For
Emergency Bus E2
SP-1080 was performed to obtain flow, pressure, and
temperature test data to be used for future system
evaluations such as determining the feasibility of balancing
the SI cold leg flows. Preliminary evaluation of the data
confirmed that either the A or B SI pump could deliver, via
any two cold leg injection pathways, a flow rate in excess
of that assumed in the accident analyses. However, the data
contained discrepancies which appeared to limit the data's
usefulness for rigorous analyses. Specifically, the
inspectors observed that when the minimum flow isolation
valves SI-856A and B were closed, the pressure in the three
injection paths increased; however, the flow rates in two
paths increased as expected while the flow rate in the third
path decreased by approximately 5 percent (13 gpm).
This
may have resulted from inaccuracies in the flow measuring
instrumentation. Also, the pressure gauges used to measure
pressure in the three injection headers were in 10 psig
divisions. Thus, the pressure instruments could not provide
the necessary precision to measure the small pressure
6
changes with sufficient accuracy to allow the data to be
used in analyses. Additional testing during the next RO was
being considered.
Emergency Bus UV Trip Channel Functional Testing
On September 27, 1991, the NRC issued TS Amendment no. 136
to authorize operation until RO 14 without the El and E2 UV
trip channels being fully tested as required by TS (see IR
91-20).
The inspectors observed performance of SP-1128 and
1129 which tested the previously untested portions of the UV
trip logic. SP-1128 was satisfactorily completed; however,
three problems were identified during performance of SP
1129.
The first problem involved a wiring discrepancy
between the as built configuration and the actual field
installation. The labels on two wires were switched inside
the electrical panel. This resulted in the test procedure
not working as written; however, the load shed function was
unaffected. Testing was continued after the wires were
labeled in accordance with the CWD. The second problem
involved the 480V Bus 3 Main Breaker (52/15B) not reclosing
after having been cycled once. The test was continued after
the breaker latching mechanism and alarm switch were
repaired. The third problem involved the discovery that the
C CCW pump received a trip signal from only one UV trip
channel. The B CCW pump received a trip signal from both UV
trip channels. The UV CWDs B-190628 sheets 276 and 277
showed contacts from both UV trip channels being in the
C CCW pump circuit, whereas the C CCW pump CWD B-190628
sheet 209 showed that only the channel 1 UV trip channel was
part of the pump control circuit. The C CCW pump breaker
was confirmed to be wired in accordance with the C CCW pump
drawing. SP-1129 was then completed without any further
major difficulties. At the end of the report period, a
temporary modification was being developed to wire the other
trip channel into the C CCW pump trip circuit. The
temporary modification will install wiring in the breaker
side of the cubical prior to restart. When the emergency
bus is de-energized during the next refueling outage for
PMs, a permanent modification will rewire the circuit in a
more conventional manner (i.e., in the back of the breaker
cubical).
Installation of the permanent modification is
identified as an IFI: Review C CCW Pump Trip Circuit
Modification Installation, 92-11-02.
No violations or deviations were identified. Except as
noted above, this program area was adequately implemented.
7
5.
Monthly Maintenance Observation (62703)
The inspectors observed safety-related maintenance
activities on systems and components to ascertain that these
activities were conducted in accordance with TS, approved
procedures, and appropriate industry codes and standards.
The inspectors determined that these activities did not
violate LCOs and that required redundant components were
operable. The inspectors verified that required
administrative, material, testing, radiological, and fire
prevention controls were adhered to. In particular, the
inspectors observed/reviewed the following maintenance
activities:
CM-031
Service Water Booster Pump
Maintenance
Crane Swing Check Valve Inspection
WR/JO 90-ANRZ1
A EDG Exhaust Expansion Joint
Replacement
WR/JO 91-AIGAl
A MDAFW Pump Inspection/PM
WR/JO 91-ANGR1
Unit Auxiliary Transformer Bus Bar
Inspection
WR/JO 92FLJ525
MCC 6 Compartment Inspection/PM
A MDAFW Pump Impeller Inspection
On April 16, 1992, while observing work activities
associated with WR/JO 91-AIGA1, the inspectors examined the
visible part of the A MDAFW pump rotating assembly. There
was no evidence of recirculation damage as observed in 1989
(see IR 89-17).
SW Valve Removal Prior To Scheduled Removal
On April 21, SW valves SW-374 and 376 (the A and B SW pump
discharge check valves, respectively) were removed from the
piping system. These valves had been scheduled to be
removed after the fuel was off loaded from the reactor
vessel due to SW system seismic considerations. Since all
four SW pumps discharge into a common header, the removal of
the valves placed the operating portion of the SW in a
configuration which had not been seismically evaluated. An
engineering evaluation later determined that the piping in
the operating portion of the SW system had remained
seismically qualified. The early removal was in part caused
8
by the A and B SW pumps being under clearance, which allowed
personnel to believe that it would be alright to work these
valves early if they had the opportunity. Prior to their
removal, personnel failed to adequately coordinate the work
activity with the planning and scheduling organization. At
the end of the report period, long term corrective actions
had not been developed. The failure to implement
instructions appropriate to the circumstances (i.e., the
work schedule) was a violation of 10 CFR 50 Appendix B
Criterion V. This item is identified as a VIO: Failure To
Implement Appropriate Instructions During SW-374 and 376
Valve Maintenance, 92-11-03.
MCC 6 Inspection
On April 27, 1992, the inspectors witnessed performance of
PM route E-023 on safety related MCC 6. The route required
inspection of the motor starter contacts, circuit bridging
and meggering, and general inspection and cleaning. The
route also specified that the thermal overload be checked
for wear. Discussion with the I & C technicians performing
the work revealed that this instruction appeared not to be
very meaningful. The only check being performed for wear
was a visual external examination for signs of overheating.
The inspectors discussed this item with the WR/JO planner.
The planner indicated that he was unfamiliar with the intent
of this step. The planner initiated a note to the
maintenance procedure writers to clarify this item when the
route is revised under the rewrite program. The inspectors
observed that the MCC compartment components were in good
condition. Work requests were being issued to replace
pitted contacts when necessary.
B SWBP Discharge Check Valve Inspection
On May 6, 1992, the inspectors witnessed the B SWBP
discharge check valve (SW-560) disassembly in accordance
with PM-302.
During B SWBP operation, this valve had been
identified via the deficiency tag program as emitting an
unusual noise. Valve inspection revealed that the hinge
pin's staking pin had come out. This allowed the hinge pin
to wobble inside the disc arm causing significant wear to
the arm. However, the valve disc seated properly. The worn
components were replaced and the valve returned to service.
The staking pin was missing and could not be located. The A
SWBP discharge check valve is also to be inspected during
this RO.
CCW Pump Suction Strainers
During replacement of the three CCW pump suction isolation
valves, a strainer was found in the each of the pumps'
9
suction piping. P&ID no. 5379-376, sheet 1, revision 25,
contained a note which indicated that the temporary pump
suction strainers had been removed. Based upon this note,
the strainers were removed. A large rubber piece, possibly
part of a butterfly valve disc seal, was found in one of the
strainers. Actions were initiated via ACR 92-127 to locate
the source of the rubber piece and repair the component as
deemed necessary. The cognizant engineer indicated that the
rubber piece could have potentially restricted flow at the
pump impeller inlet. Engineering was evaluating the
desirability of installing new strainers in the CCW system.
The inspectors noted that the removed strainers were more
typical of permanently installed strainers than of the kind
usually used as temporary strainers. Whether or not the
strainers found in the piping were intended to be installed
is considered as an URI: Determine If CCW System Design
Included Pump Suction Strainers, 92-11-04.
One violation was identified. Except as noted above, this
program area was adequately implemented.
6.
Modifications (37828)
During revision of operating procedures, it was discovered
that the RHR recirculation piping configuration being
installed per M-1087, RHR Pumps Minimum Flow Recirculation,
would not allow the RHR Hx outlet temperature to be heated
to within 25 degrees F of the RCS prior to placing the RHR
system in shutdown cooling. The existing recirculation
line, located downstream of the RHR Hx bypass line, allowed
flow to bypass the RHR Hxs as necessary to allow warm-up of
the RHR system. The new RHR recirculation piping
configuration, involving larger and separate recirculation
flow paths for each RHR pump, was connected upstream of the
RHR Hx bypass line. The new configuration would recirculate
only cooled water back to the RHR pump suction line. Thus,
the new configuration did not provide the ability to warm
the RHR system to the above stated temperature criteria.
The temperature criteria is contained in GP-007, Plant
Cooldown From Hot Shutdown To Cold Shutdown, revision 24,
step 5.2.32.10. M-1087 has been revised to retain the
existing recirculation line as well as installing the new
recirculation flow paths.
The normal development and review processes for M-1087
failed to detect the above described design deficiency. The
problem was detected by Operations personnel during
development of procedure changes required by M-1087.
The
inspectors noted that the procedures could have easily been
revised without detecting this problem; therefore, the
discovery reflected outstanding attention to detail by the
procedure preparer. During M-1087 development, the
10
responsible engineer apparently knew that the RHR system was
to be warmed prior to placing it in shutdown cooling.
However, he failed to understand that in this process the
bypass flow around the RHR Hxs was more significant that the
heat added by the RHR pumps. A contributor to the design
activity breakdown was the lack of documentation for the
functional or operating basis of the RHR recirculation line.
An ACR has been issued to review the design activities
associated with M-1087. However, corrective action to
preclude future similar events has not been developed. The
failure to assure that the design basis for the RHR system
was correctly translated into specifications, drawings,
procedures, and instructions as required by 10 CFR 50
Appendix B Criterion III is identified as a VIO: Failure To
Translate RHR System Design Basis Into M-1087, 92-11-05.
One violation was identified.
Except as noted above, this
program area was adequately implemented.
7.
Exit Interview (71707)
The inspection scope and findings were summarized on May 13,
1992, with those persons indicated in paragraph 1. The
inspectors described the areas inspected and discussed in
detail the inspection findings listed below and in the
summary. Dissenting comments were not received from the
licensee. The licensee did not identify as proprietary any
of the materials provided to or reviewed by the inspectors
during this inspection.
Item Number
Description/Reference Paragraph
92-11-01
VIO -
Failure To Implement FP-005
Resulted In Alert Declaration
(Paragraph 3)
92-11-02
IFI -
Review C CCW Pump Trip
Circuit Modification Installation
(Paragraph 3)
92-11-03
VIO -
Failure To Implement
Appropriate Instructions During
SW-374 and 376 Valve Maintenance
(Paragraph 5)
92-11-04
URI -
Determine If CCW System
Design Included Pump Suction
Strainers (Paragraph 5)
92-11-05
VIO -
Failure To Translate RHR
System Design Basis Into M-1087
(Paragraph 6)
8.
List of Acronyms and Initialisms
a.m.
Ante Meridiem
ACR
Adverse Condition Report
Component Cooling Water
CFR
Code of Federal Regulations
Corrective Maintenance
CWD
Control Wire Diagram
Diesel Generator
Emergency Action Level
F
Fahrenheit
Fire Protection
General Procedure
gpm
gallons per minute
Hx
Heat Exchanger
I & C
Instrument And Control
i.e.
That is
IFI
Inspector Followup Item
IR
Inspection Report
LCO
Limiting Condition for Operation
M
Modification
Motor Control Center
Motor Driven Auxiliary Feedwater
Notice of Unusual Event
NRC
Nuclear Regulatory Commission
OST
Operations Surveillance Test
p.m.
Post Meridiem
Piping and Instrumentation Diagram
Preventive Maintenance
psig
pounds per square inch -
gage
Refueling Outage
Self-contained Breathing Apparatus
SEC
Site Emergency Coordinator
Safety Injection
Special Procedure
SWBP
Service Water Booster Pump
TS
Technical Specification
Unresolved Item
V
Volts
Violation
WR/JO
Work Request/Job Order