ML20024F368
| ML20024F368 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 07/06/1983 |
| From: | Bemis P, Garner W, Myers D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20024F355 | List: |
| References | |
| 50-324-83-17, 50-325-83-17, NUDOCS 8309090318 | |
| Download: ML20024F368 (6) | |
See also: IR 05000324/1983017
Text
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION
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REGION 11
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101 MARIETTA ST N.W SUITE 3100
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ATLANTA. GEORGIA 30303
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Report Nos.: 50-325/83-17 and 50-324/83-17
Licensee:
Carolina Power and Light Company
411 Fayetteville Street
Raleigh, NC 27602
Docket Nos.:
50-324 and 50-325
License Nos.:
Facility Name: Brunswick 1 and 2
Inspection at Brunswick site near Wilmington, North Carolina
Inspectors:
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D. O. Myers, Senior Resident Inspector
Date ' Signed
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4/30/93
L. W. Garner, Resident Inspector
'Dats Signed
Approved by: 64 k,
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P. Bemis, Section Chief 0
Date Signed
Division of Project and Resident Programs
SUMMARY
Inspection during the period May 9 - June 9,1983
Areas Inspected
This special, unannounced inspection involved 50 inspector hours on site in the
review of the circumstances surrounding the condenser off gas radiation monitor-
ing system inoperability and the off gas stack isolation valve inoperability.
Results
Of the 2 areas inspected, one violation was identified in one area; (Failure to
comply with Technical Specification action statement, paragraph 5.)
8309090318 830829
PDR ADOCK 05000324
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REPORT DETAILS
1.
Persons Contacted
Licensee Employees
A. Bishop, Technical Support Manager
J. Boone, Engineering Supervisor
L. Boyer, Assistant to General Manager
T. Brown, I&C/ Electrical Maintenance Supervisor (Unit 1)
G. Campbell, Mechanical Maintenance Supervisor (Unit 2)
- J. Chase, Manager - Operations
G. Cheatham, E&RC Manager
R. Coburn, Director QA/QC
J. Cook, E&RC Foreman
R. Creech, I&C/ Electrical Maintenance Supervisor (Unit )
- C. Dietz, General Manager
J. Dimmette, Maintenance Manager
W. Dorman, QA Supervisor
- K. Enzor, Director Regulatory Compliance
- J. Harness, Plant Operations Manager
W. Hatcher, Security Specialist
A. Hegler, Manager - Operations
P. Howe, Vice President, Brunswick Nuclear Project
W. Martin, Principle Engineer / Operations
G. Milligan, Principle Engineer /0nsite Nuclear Safety Section
D. Novotny, Regulatory Specialist
- J. O'Sullivan, Prcject Specialist
R. Poulk, Senior Regulatory Specialist
C. Treubel, Mechanical Maintenance Supervisor (Unit 1)
L. Tripp, RC Supervisor
Other licensee employees contacted included technicians, operators and
engineering staff personnel.
- Attended exit interview
2.
Exit Interview
The inspection scope and findings were summarized on June 10, 1983 with
those persons indicated in paragraph I above. Meetings were also held with
senior facility management periodically during the course of this inspection
to discuss the inspection scope and findings.
3.
Licensee Action on Previous Inspection Findings
Not inspected.
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Unresolved Items
Unresolved items were not identified during this inspection.
5.
Condenser Off-Gas Radiation Monitoring System Inoperability
On May 10, 1983, the licensee notified the NRC, via a 10 CFR 50.72 Immediate
Report, that the Unit 2 condenser off gas radiation monitors had been
isolated when they were required by Technical Specification (TS) 2.5.2.d to
have been operable. Unit 2 was at 55% power at the time of this discovery;
Unit I was in cold shutdown and was unaffected by this event. The condenser
off gas radiation monitors were promptly returned to their proper operable
alignment and a licensee investigation was initiated.
The condenser off gas radiation monitoring system is one of two process
radiation monitoring systems designed to initiate automatic actions to limit
the release of radioactive gaseous effluents from the reactor via the main
stack.
The condenser off gas radiation monitors sample tha non-condensible gaseous
discharge of the steam jet air ejectors (SJAE) enroute to the off gas
system's 30 minute hold-up line.
The radiation monitors (DIZ-K601 A & B)
have alarms that alert the operator if the activity of the condenser
non-condensible gaseous discharge reaches a level that, if continued, could
allow the annual discharge rate to be exceeded. Also, the monitors provide
a radiation Hi-Hi alarm which initiates an isolation of the off gas system
(by closing valves A0G-HCV-102 after a fifteen minute time delay) to prevent
exceeding TS short term gaseous release rates.
In the event of a significant fuel failure the main steam line radiation
monitors would provide a redundant action of limiting off site releases by
initiating the closure of the main steam isolation valves. This action
stops the supply of fission products and reduces the transport of these
fission products to the environs through the condenser by securing the steam
supply to the SJAE, causing them to isolate - effectively " bottling-up" the
condenser. The Unit 2 main steamline radiation monitoring system was
operable and capable of providing this isolation function during this event.
Subsequent licensee investigation of this event determined that as the
result of the failure to complete the proper restoration of clearance 2-506,
several valves were mispositioned including off gas radiation monitor
iselation valves OG-V35 and 0G-V36. The improper valve position of OG-V35
and OG-V36 resulted in the inoperability of the monitors.
Clearance 2-506 was established on April 10, 1983, for plant modification
80-2288. This was an extensive clearance for an off gas system modification
and was subsequently pcrtially restored to support restart of the Unit 2
reactor, which was shutdown for an equipment maintenance outage.
It was
this partial restoration, which occurred on April 17, 1983, that called for
the opening of valves OG-V35 and OG-V36. The licensee's post-event
investigation determined that four valves which were expected to have been
reopened were left closed during the clearance restoration. Two of these
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valves (OG-V35 and OG-V36) isolated the radiation monitors.
The remaining
two valves isolated a sample vial which had no adverse effect on plant or
processes.
Interviews with the personnel responsible for restoration of
this. clearance determined that a lack of concise communications between the
control operator ordering the restoration and the auxiliary operator
- performing the restoration resulted in the valves being left closed.
Unit 2
did not restart from the equipment maintenance outage until May 8, 1983.
As a consequence of OG-V35 and 0G-V36 being closed, a low flow condition
existed in the monitoring system when the SJAE were placed into service,
during restart of Unit 2 on May 8, 1983. During the period May 8-10, 1983,
several control room indications that should have alerted them to this
condition were repeatedly overlooked or misinterpreted by the operations
staff. These indications included:
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The abnormally low off gas activity level indicated by the SJAE
monitors (<10 mr/hr. versus normal 100 mr/hr.) for the existing power
level.
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Failure of the SJAE monitor strip chart recorders to indicate an
increasing activity level consistent with the increasing levels
indicated by the main stack monitor and the main steam line radiation
monitors as. plant power increased. These monitor strip chart recorders
are located on the main control board in the control room.
The continued presence of the annunciator indicating a hi/ low flow
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condition in the monitor sample lines after the SJAE had been placed in
service.
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Recording in the Daily Surveillance Report (DSR) of virtually the same
once per shift readings, for the SJAE monitors, for several consecutive
shifts even though power had increased from 0% to approximately 55%.
The closed radiation monitor isolation valves were discovered on May 10, as
a result of a concern noted by the shift supervisor, during shift turnover
at 11:30 p.m. on May 9, that the SJAE radiation monitors did not appear to
be responding normally for increasing reactor power.
Subsequent investi-
gations by the operating shift personnel lead to the identification of the
closed isolation valves and the presence of the hi/lo flow alarm. The
isolation valves were reopened and the monitors returned to operable status
at 4:00 a.m. on May 10, 1983.
Technical Specification Appendix B, paragraph 2.5.2.e, requires that if the
augmented off gas (A0G) is out of service and the air ejector off gas
monitors are inoperative, a reactor shutdown shall be initiated so that the
reactor will be in the hot shutdown condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
Contrary to the above, during the period from 11:00 p.m. , on May 8,1983, to
4:00 a.m., on May 10, 1983, with the Unit 2 augmented off gas system out of
service and the air ejector off gas monitors inoperative, a reactor shutdown
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was not initiated and the reactor was not in hot shutdown within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />,
although, sufficient information existed to alert the operator to the
conditions existing which required the reactor shutdown.
This is a violation and applies to Unit 2.
6.
Off-Gas Stack Isolation Valve Inoperable
On May 21, 1983, the licensee reported that control power to the Unit 2
solenoid controlled, air operated off gas stack isolation valve was found
off, rendering the valve inoperable.
For the existing plant conditions, the
Unit 2 off gas stack isolation valve was required by Technical Specification 2.5.2.d. to have been operable.
The control power for the solenoid was
promptly restored returning the stack isolation valve to an operable status
and a licensee investigation of this event was initiated.
Unit 2 was at 90%
of rated thermal power at the time of this event; Unit I was shutdown for
refueling. The Unit 1 stack isolation valve, although similarly affected,
was not required to be operable in the existing plant condition.
The off gas stack isolation valves are designed to close, after a 15 minute
time delay, in response to a radiation Hi-Hi level trip of the condenser
off gas radiation monitors.
This valve closure isolates the 30 minute
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hold-up line from the main stack to prevent exceeding short term gaseous
release limits. These stack isolation valves (1-A0G-H0V-102 for Unit I
and 2-A0G-H0V-102 for Unit 2) are air (to close) operated valves with their
air signals controlled by its respective solenoid valve.
The solenoid valve
must energize to cause a stack isolation valve to close.
At approximately 12:30 p.m. on May 21, 1983, a contractor startup engineer,
working on the installation of the augmented off gas system, notified the
Unit 2 shift foreman that electric panels HB5 and HB8 were deenergized. An
auxiliary operator (AO) was dispatched to the panels and they were
immediately reenergized. The HB5 and HB8 electric distribution panels,
which are physically located in the augmented off gas building, provide
control power to the Unit 1 and Unit 2 off gas stack isolation valve
solenoids.
The licensee began an immediate investigation of this event, conducting
extensive interviews with operations and construction personnel to determine
when and by whom panels HB5 and HB8 were deenergized. This investigation
has failed to determine the exact time at which the panels were deenergized
or by whom, although, it has been determined that the panels were known to
be energized at approximately 1:00 a.m. on May 21, 1983 (12 1/2 hours prior
to their being found deenergized). Additionally, it has been determined that
these panels had been deenergized and then reenergized several times during
the previous week.
At the time of the event, panels HB5 and HB8 were undergoing extensive
modification in conjunction with the installation of the augmented off gas
system. The associated modification procedures required that these panels
be worked in the energized condition.
Interviews with the contractor
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startup engineers, working on newly installed systems powered from these
panels, revealed that during the week prior to May 21, these newly installed
systems had beenf ound deenergized on several occasions. These occurrences
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were not reported _to the plant staff as the startup engineers attributed the
deenergized status to wiring problems in the newly installed equipment. The
startup engineer who reported-the deenergized panels to the control room on
May 21 did so as a result of trouble shooting associated with these modifi-
cations being denergized.
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Despite the inability to identify the specific individual or individuals
responsible for deenergizing panels HB5 and HB8, the licensee has attributed
the repositioning of these breakers to construction personnel not desiring
to work on the associated modifications in the energized condition. Breaker
and valve lineup checks of other systems located in the A0G building have
not identified any additional deficiencies.
It is noted'that no remote indication of control power availability for
these valves, valve position indication is powered from a separate circuit
which remained energized throughout this event, thus, no information was
available which should have alerted the operator to this condition.
No
other equipment important to safety was affected by deenergizing these
panel s.
As a-result of_this event, the licensee has initiated increased administra-
tive control designed to minimize the potential for reoccurrence of this or
similar type events.
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Technical Specifications'2.5.2.e require that if the condenser off gas
monitors are incapable of initiating automatic closure of the stack
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isolaticn~ valves, a shutdown shall be initiated so that the reactor will be
~in hot shutdown.within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. .Since the_ licensee took.immediate
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corrective action'(reenergizing panels HB5 and HBS) following the identifi-
cation'of the deenergized panels and' subsequent investigation indicated that
the licensee did not have knowledge of this condition nor did other means
(remote breaker position indication) exist which should have alerted the
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licensee, the' action required by Technical Specification 2.5.2.e were
satisfied within the allotted time interval.
No violations or deviations occurred in this area.
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