ML20058B089
| ML20058B089 | |
| Person / Time | |
|---|---|
| Site: | Crystal River |
| Issue date: | 10/17/1990 |
| From: | Crelenjak R, Holmesray P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20058B085 | List: |
| References | |
| 50-302-90-32, NUDOCS 9010290390 | |
| Download: ML20058B089 (6) | |
See also: IR 05000302/1990032
Text
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NUCLE An Rt GULATOnY COMMISslON
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1011AARIETT A STREET,N.W.
AT LANT A, G E ORGI A 30323
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Report No:
50-302/90-32
Licensee:
Florida Power Corporation
3201 34th Street, South
St. Petersburg, FL 33733
Docket No: 50-30'2
License No: DPR-72
facility Name:
Crystal River 3
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InspectionConducte). September 18 - October 5, 1990
1nspector:
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/d//7 N O
P. lMlmes~~ ay, Wnior ResiKnt Inspector
D6te Sfgned
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/0//788
Approved by:
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R.7Crlenjak, ~5ettion ChheT
Ddte Ylgned
Division of Reactor Projects
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SUMMARY
Scope:
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This special unannounced reactive inspection was conducted by the tsenior-
resident inspector to review the events resulting in a breach of ~ reactor
building (RB) containment and the events surrounding the lack of leak integrity-
of an encapsulation assembly providing a seccndary boundary to a portion of the
decay heat (DH) system.
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Results:
With the plant in MODE 1, valve DH-43, the first valve outside the RB in the
suction line from the RB sump for the "B" train of DH, was improperly operated
resulting'about 7:00 p.m. the same day.in a breach of_RB containment from about 4:
1990, to
This breach of containment is in
vi61ation of Technical Specification (TS) 3.6.1.1 which requires containment
integrity in MODES 1, 2, 3, and 4.
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The guard assemblyfencapsulating a portion of the DH piping and the first_ valve
immediately outside the RB containment wall was found by the licensee not to be
leak tight as required by Chapter 5 of the Final Safety Analysis Report (FSAR).'
-This lack of' integrity of the encapsulation is a violation of 10 CFR 50,
Appendix B, Criterion III which requires that design measures shall provide for
verifying or checking the adequacy of design.
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9010290390 993o37
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REPORT DETAILS
1.
Persons Contacted
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Licensee Employees
- J. Albr.rdi, Manager Nuclear Site Support
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- W. Bandhaver, Nuclear Operations Superintendent
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- G. Boldt, V4,ce President Nuclear Production
- J. Co'.oy, Nuclear Principal Mechanical Engineer
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- P. V,cKee, Director, Nuclear Plant Operations
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- S. Robinson, Nuclear Chemistry and Radiation Protection Superintendent
- V. Roppel, Manager, Nuclear Plant Maintenance
- W. Rossfeld, Manager, Nuclear Compliance
- F. Sullivan, Manager, Nuclear Plant Systems Engineering
- M. Williams, Nuclear Regulatory Specialist
- K. Wilson, Manager, Nuclear Licensing
Other licensee employees contacted included operations, engineering
maintenance and corporate personnel,
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- Attended exit intery, w
Acronyms and initialisms used throughout this report are listed in the
last paragraph.
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2.
ContainmentBreachFollowup(93702)
On September 18, 1990, with the reactor op(erating at full power, theES) train out of
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licensee took the "B" Emergency Safeguards
perform planned maintenance on DHV-40 which had a seat leak (See
Attachment 1 for a diagram of a portion of the DH system).
Prior to the
repair,.DHV-43, a containment isolation valve, was cycled to allow water
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in the pipe below DHV-40 to drain back into the RB sump.
DHV-43 was being
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operated from the MCC prior to placing a clearance tag on the breaker for
DHV-43.
This process was accomplished at approximately 4:30 a.m. and the
breaker to DHV-43 was opened when the position indicating light indicated
the valve was closed.
A drain valve and- a vent valve located in the
auxiliary building were open to allow the remainder of the piping to drain
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to the auxiliary building sump.
At about 6:45 p.m., BSV-58, a one inch demineralized water valve to the DH
pump, was remcVed by maintenance personnel to perform maintenance. When
the valve was removed air flow was observed by maintenance personnel
emanating from the piping.
The air flow was immediately stopped with
plastic and tape.
Air flow was also found emanating from the DH vent
valve which had been opened earlier.
The SS00 then ordered DHV-43 to be
manually closed and the air flow ceased at 7:00 o.m.
It was concluded
that DHV-43 had been partially open permitting air to flow from the RB
sump to ' the auxiliary building.
The operator who closed the valve
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reported that, approximately four or five turns of the handwheel were
required to fully shut the valve.
The operator could not be positive as
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to the number of turns to close the valve because some turns were made
without the handwheel being engaged on the valve stem.
DHV-43 was
declared inoperable by the licensee at about 6:45 p.m. on September 18,
1990, and TS 3.6.3.1.b action statement was entered which states,
"b.
Isolate each affected penetration within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> by use of at least one
deactivated automatic valve secured in the isolation position or, d. Be in
at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within
the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />."
DHV-43, although not an automatic valve, was
manually shut about 7:00 p.m. September 18, 1990, and had been deactivated
at about 4:30 a.m. on September 18, 1990.
The valve was declared operational and the TS action statement was exited
on September 20, 1990, af ter the valve position indicating light limit
switch was adjusted.
The limit switch activates the valve position
indicator lights on the main control board and at the MCC.
The licensee
speculates that the valve travel was interrupted (prior to the valve being
fully closed) when the operator opened the valve breaker upon illumination
of the closed valve position light.
Apparently, this closed position
light illuminated prior to the valve travel being stopped by the torque
switch (fullyclosed).
Subsequent to the event, the licensee was able to estimate the amount
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DHV-43 was open by calculating-the orifice size based. on. the recorded
level decrease from the RB sump during the period + hat the RB sump was
draining to the auxiliary building.
Based on this information, the
licensee determined that DHV-43 was about two handwheel turns open (850
turns is full open).
The licensee's calculations show that two handwheel
turns open would allow a flow of 119 SCFM of air and 81.8 gpm of water at
design pressure of 53.9 psig.
These calculations show that containment
leakage requirements specified in TS 3.6.1.2 would have been exceeded.
DHV-43 is a 14 inch, motor operated, gate valve which is normally shut
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during operation but has a post accident position of open to provide a
suction from the RB sump to the B train DH pump in recirculating phase of
the accident.
This event was reported to the NRC duty officer on September 20, 1990,
-af ter the licensee's calculations showed that a breach i ' containment had
occurred.
With the reactor operating in MODE 1, the established flow path from the
RB sump to the auxiliary building through DHV-43 and the DH system vent -
and drain valves is a breach of RB containment and a violation of TS 3.6.1.1.
This condition existed for about fourteen and one half hours.
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Violation - (50-302/90-32-01):
Breach of containment in violation of TS 3.6.1.1.
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3.
Decay Heat System Guard Pipe followup (93702)
On September 24, 1990, with the reactor at full power, the " area owner"
was making a walkdown of the "B" decay heat pit.
He noticed that the
guard encapsulation for DHV-43 wn not leak tight in that two small
diameter pipe nipples did not contain plugs.
The area owner, an
operations assistant shif t supervisor, wrote a memorandum to engineering
requesting information as to whether the nipples should be open or
plugged.
On September 25, 1990, the system engineer accompanied by a
senior reactor operator examined the guard enclosure for both DH trains
and found the plugs missing on both DH train encapsulations.
The system
engineer referred operations to the FSAR chapter 5 which states:
"The Decay Heat System Reactor Building Sump penetrations contain
only one motor operated isolation valve 4cated outside containment.
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These valves are required to open post-LOCA for switchover to
recirculation mode emergency core cooling."
" Penetrations 345 and 346 have only one containment isolation valve
each. The second barrier, which is required in order to meet the CR3
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catainment isolation design basis, is provided by an encapsulation
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aroend sach recirculation line from the containment to beyond the
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'irst 1 solation valve.
This encapsulation is leak-tight at contain-
ment design pressure and is not directly connected to the containment
sump or atmosphere.
A single passive or active failure in these
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lines or encap:ulations will not provide a path for leakage to the
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environment."
The drawing for the eeapsulation (FPC Drawing Number P0-301-621) details
the two socket weld adapters but does not show any attachment or closure
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devices.
Therefore, the encapsulations are in accordaace with the
drawings.
There is no test data, readily available, to indicate that the
encapsulation is capable of withstanding containment design pressure. The
licensee has pluggad the openings but has not tested the encapsulation.
10 CFR 50, Appendix B, Criterion III states:
"The design control measures
shall provide for verifying or checking the adequacy of design, such as by
the performnce of design reviews, by the use of alternate or simplified
calculation methods, or by the performance of a suitable testing program."
The condition existing in the plant, with the encapsulations for both
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trains of the' DH system in accordance with the drawings but not in
accordance with the design basis, indicates that the design control
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measures required by 10 CFR 50, Appendix B, Criterion til were not
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effective and represent a violation of this Criterion.
Violation (50-302/90-32-02):
Failure to provide adequate design control
measures as required by 10 CFR 50, Appendix B, Criterion 111.
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4.
ExitInterview(30703)
The inspector met with licensee representatives (denoted in paragraph 1)
at the conclusion of the inspection on October 9,1990.
During this
meeting, the inspector summarize; the scope and findings of the inspection
as they are detailed in this repu t.
The licensee representatives acknowledged the inspector's comments and did
not identify as proprietary any of the materials provided to or reviewed
by the inspectors during this inspection.
5.
Acronyms and Abbreviations
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BSV - Building Spray Valve
CFR - Code of Federal Regulations
DH
- Decay Heat System
DHV - Decay Heat Valve
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- Emergency Safeguards
FPC - Florida Power Corporation
FSAR - Final Safety Analysis
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GPM - Gallons per Minute
LOCA - Loss of Coolant Accident
MCC - Motor Control Center
- Reactor Building
SCFM - Standard Cubic feet per Minute
SSOD - Shift Supervisor on Duty
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TS
- Technical Specifications
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