ML17157C176
| ML17157C176 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna |
| Issue date: | 01/27/1993 |
| From: | Jason White NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML17157C175 | List: |
| References | |
| 50-387-92-29, 50-388-92-29, NUDOCS 9302100394 | |
| Download: ML17157C176 (44) | |
See also: IR 05000387/1992029
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION I
Inspection
Report Nos.
50-387/92-29; 50-388/92-29
License Nos.
Licensee:
Pennsylvania Power and Light Company
.2 North Ninth Street
Allentown, Pennsylvania
. 18101
Facility Name:
Inspection At:
Susquehanna
Steam Electric Station
"
Salem Township, Pennsylvania
Inspection
Conducted:
Inspectors:
Approved By;
November 10, 1992 - December 31, 1992
I
G. S. Barber, Senior Resident Inspector,
D. J. Mannai, Resident Inspector, SSES,
,i
/r
J. white, Chief
,Reactor Projects Section No. 2A,
ate
Ins ection Summa:
This inspection report documents safety inspections of station activities
including: plant operations; radiation protection; surveillance and maintenance;
and safety
assessment/quality
verification.
Findings and conclusions are summarized in the Executive
Summary.
'3021'00394
930127
ADOCK 05000387
6
- 1
EXECUTIVE SUMMARY
Susquehanna
Inspection Reports
~ -50-387/92-29; 50-388/92-29
November 10, 1992
- December 31, 1992
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Operations (30702, 71707, 71710)
A Unit 2 turbine trip/reactor scram occurred at 10:14 a,m., November 12, during a
surveillance on the "A" channel of the feedwater (FW) high level trip switches.
The plant
'as
subsequently
stabilized in hot shutdown.
The turbine trip was caused by an'Agastat
relay failure for the "C" high level trip channel.
Two anomalies were identified by the
licensee,'s post-trip review:
(1) the reactor feed pump (RFP) turbines did not trip as
expected;
(2) two of three non-safety related feedwater heater (FWH) strings isolated due to
excessive flashing in the high'pressure
heaters.
Proper licensee actions'were taken for the
FWH anomalies.
The RFP turbine trip failures were due to inadequate contact makeup of
the "A" trip channel's Agastat (EGP Series) relay.
The licensee is sending this relay off-site
to determine ifthe specific failure mechanism
has generic implications.
The "C" channel's
premature failure was traced back to an early installation error that placed an AC relay in a
DC circuit application.
These issues remain unresolved pending final review by the licensee
and evaluation by the NRC.
Section 2.2.1 pertains.
Because of a continually degrading differential pressure signal, the licensee declared the Unit
2 "B" Reactor Water Cleanup (RWCU) High Flow channel inoperable on November 17, To
prevent the expected
increase in reactor water conductivity which might necessitate
unit
shutdown,'a temporary waiver of compliance was requested for Technical Specification (TS) 3.3.2 to lengthen the time required to isolate the RWCU system. After proper consideration
and evaluation, the NRC granted the temporary waiver of compliance on November 18.
.Over the next several days, the licensee and the NRC held numerous discussions
regarding
the need for further extensions to the original waiver.
Numerous problems were encountered
during these interactions.
The licensee subsequently initiated an Event Review Team (ERT)
to identify and correct the noted deficiencies. NRC review of these concerns willremain
unresolved pending final review by the licensee's ERT.
Section 2.2.4 pertains.
The inspector performed an Engineered
Safety Feature (ESF) walkdown of the Control Room
Emergency Outside Air Supply (CREOASS) system,
The inspector determined the system
was properly aligned and capable of performing its intended safety function.
The system was
maintained in good physical,condition.
However, several minor deficiencies were identified.
The licensee's
actions for these deficiencies was appropriate.
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The inspector reviewed hourly fire watch records for the month of September,
1992.
The
subject watches were performed by site contract personnel.
While no fire watches had been
missed, two individuals failed to properly perform a required fire watch round.
One
individual admitted that he failed to check the 660'levation of the "A" Emergency Diesel
Generator Bay and was suspended
without pay for five days.
The licensee determined that
the other individual lied about surveying the area.
The individual was subsequently
terminated.
The inspector concluded that the licensee's implementation of fire protection
requirements
was effective.
/
Radiological Controls (71707)
The inspector evaluated susceptibility of either Susquehanna
unit to highly concentrated
radiation beams similar to those observed during July 7-9, 1992 at the,Limerick Nuclear
Generating Station (LNGS).
These beams resulted from a highly concentrate'd
neutron
streaming through an instrument penetration that was poorly shielded.
They were detected at
LNGS during drywell entries performed at power to repair a leaky containment isolation.
valve, At Susquehanna,
the licensee, by policy, has not made any at-power entries to either
units'rywell since commercial operation.
To address
this concern further, the licensee
modified the containment entry procedure to prohibit entries at power.
Inspector review of
post shutdown gamma doses showed no unusual streaming.
The inspector found that the
licensee actions in changing the containment entry procedure to be strong and conservative.
Section 3.2.2 pertains.
On November 12, a routine sample of the "B" Auxiliary Boiler identified radioactive gases in
the auxiliary steam system.
The licensee secured the leak by closing and administratively
controlling a manual isolation valve.
The inspector concluded the licensee promptly
identified and determined the cause of the auxiliary boiler contamination.
Radiological
consequences
were conservatively
assessed.
The inspector determined immediate corrective
actions for this contamination event were adequate.
The event resulted in a minor
uncontrolled, unmonitored release that was calculated to be an extremely
small fraction
regulatory limits. However, this was the third radioactive gas leak through the auxiliary
boiler from essentially the same leak path.
The licensee's effectiveness relative to resolving
this type of occurrence remains unresolved.
Section 3.2.1 pertains.
Maintenance/Surveillance
(61726, 62703)
The licensee exercised good control of maintenance
and surveillance activities.
No scrams or
Engineered
Safety Feature (ESF) actuations were attributable to personnel or procedural error
during maintenance or surveillance activities.
A reactor scram occurred during the
performance of a surveillance but was attributed an undetectable Agastat relay failure.
111
Engineering/Technical Support (71707, 92720, 93702)
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The "E" Diesel Generator started unexpectedly in the emer'gency mode on November 13.,
The unexpected
start was attributed to an in-service failure of a normally energized Agastat
relay (4ESS1).
The failed relay was only seven months old.
The licensee plans to submit
the device to an independent laboratory for failure analysis.
Currently, the licensee intends
to replace 183 of the safety related-active and non-safety related-critical (to plant operations)
Agastat relays.
The licensee is tracking completion of this action under their deficiency
resolution program.
Section 7.2.1 pertains.
Safety Assessment/Assurance
of Quality (40500, 90712, 92700, 92701)
The inspector reviewed three Licensee Event Reports during the period.
Section 8.1
pertains.
TABLEOF CONTENTS
EXECUTIVE
SUMMARY'.
SUMMARYOF OPERATIONS...
1.1
Inspection Activities . ~....
1,2
Susquehanna
Unit 1 Summary
'1.3
Susquehanna
Unit 2 Summary
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OPERATIONS
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2.1
Inspection Activities...............................
2.2
Inspection Findings and Review of Events
2.2.1
Reactor Scram/Turbine Trip During Feedwater High Level Trip
Switch Surveillance.......,...................
2.2.2
Engineered
Safety Feature (ESF) System Walkdown - Control
Room Emergency Outside Air Supply System (CREOASS)-
Common
2.2.3
Hourly Fire Watch Records Review
2,2.4
Inoperable "B" High Flow Isolation Channel for the Unit 2
Reactor Water Cleanup System
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RADIOLOGICALCONTROLS
3.1
Inspection Activities....,..........
3.2
Inspection Findings
3.2.1
"B" Auxiliary Boiler Contamination
3.2.2
Highly Concentrated
Radiation Beams
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MAINTENANCE/SURVEILLANCE
4.1
Maintenance'and
Surveillance Inspection Activity.......
4.2
Maintenance Observations ..... ~,... ~......,...
4.3
Surveillance Observations
4.4
Inspection Findings
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5.1
Inspection Activity.....
5.2
Inspection Findings
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6.
SECURITY
6.1
Inspection Activity.....
6.2
Inspection Findings
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Table of Contents (Co'ntinued)
7.
ENGINEERING/TECHNICALSUPPORT
7.1
Inspection Activity..................
7.2
Inspection Findings
7.2.1
Diesel Generator Automatic Start Due to
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Failure ..
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SAFETY ASSESSMENT/QUALITY VERIFICATION .
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Licensee Event Reports........ ~.......
8..2
Open Items ........ ~..............
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MANAGEMENTAND EXIT MEETINGS .......
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- 'P&LEmergency Protective Guidelines Meeting
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DETAILS
1.
SUFrIMARY OF OPERATIONS
1.1
.Inspection Activities
The purpose of this inspection was to assess
licensee activities at Susquehanna
Steam Electric
Station (SSES) as they related to reactor safety and worker radiation protection.
Within each
inspection area, the inspectors documented
the specific purpose of the area under review, the
scope of inspection activities and findings, along with appropriate conclusions.
This
assessment
is based on actual observation of licensee activities, interviews with licensee
personnel,
measurement of radiation levels, independent calculation, and selective review of
applicable documents.
Abbreviations are used throughout the text.
Attachment
1 provides a listing of these
abbreviations.
1.2
Susquehanna
Unit 1 Summary
Unit 1 began the inspection period at 100% power.
On November 12, an unplanned
Engineered
Safety Feature (ESF) actuation occurred when the reactor scrammed
due to a
main turbine trip. The cause of the main turbine trip was due to a failed Agastat relay in the
"C" Feedwater High Level Turbine Trip Channel coincident with surveillance testing of the
Reactor Feedwater "A" High Level Turbine Trip Channel.
(Section 2.2.1 pertains)
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The
unit was synchronized to the grid on November 14, and reached
100% power on November
16.
On November 12, a routine sample of the "B" auxiliary boiler indicated contamination of the
auxiliary steam system with main steam as evidenced by the presence of nitrogen-13 and
fluorine-18,
The licensee prepared
a safety evaluation to allow temporary operation of the
boiler for the startup of both units.
(Section 3.2.1 pertains).
On November 13, an unplanned ESF actuation occurred when the "E" Emergency Diesel
Generator auto-started in the emergency run mode with no apparent initiation signal present.
The licensee determined
an Agastat relay failure caused
the auto-start of the diesel.
(Section
7.2.1 pertains).
On December 3, power was reduced to 60% to repair "B" and "D" condenser
water box
leaks.
Reactor power was returned to 100% on December 7. Unit 1 finished the inspection
period at 100% power.
1.3
Susquehanna
Unit 2 Summary
Unit 2 entered the inspection period in Condition 4 at the end of a refueling and inspection
outage.
The unit entered Condition
1 on November 13 and was synchronized to the grid.
Power ascension
continued and the unit reached
100% power on November 23.
On November 17, at 11:20 a.m., the "B" Reactor Water Cleanup (RWCU) system high flow
channel was declared inoperable due to the instrument degradation.
The'high flow isolation
was determined to be inoperable and a temporary waiver of compliance was granted to
preclude isolating, the reactor water cleanup system.
(Section 2.2.4 pertains).
The unit
finished the inspection period at 100% power.
2.
OPERATIONS
2.1
Inspection Activities
The inspectors verified that the facility was operated safely and in conformance with
regulatory requirements.
Pennsylvania Power and Light (PP&L) Company management
control was evaluated by direct observation of activities, tours of the facility, interviews and
discussions with personnel,
independent verification of safety system status and Limiting
Conditions for Operation, and review of facility records.
These inspection activities were
conducted in accordance with NRC inspection procedure 71707.
The inspectors performed 28 hours3.240741e-4 days <br />0.00778 hours <br />4.62963e-5 weeks <br />1.0654e-5 months <br /> of deep backshift inspections during the period.
These
deep backshift inspections covered licensee activities on weekdays between
10:00 p.m. and
6:00 a.m., and weekends
and holidays.
2.2
Inspection Findings and Review of Events
2.2.1
Reactor Scram/Turbine Trip During Feedwater High Level Trip Switch
Surveillance
At 10:14 a.m., November 12, a turbine trip occurred during a surveillance on the feedwater
high level trip switches.
A reactor scram ensued with all control rods fully inserting.
Two
safety relief valves (SRVs) opened and reseated
to compensate for the load rejection.
Reactor water level decreased
to slightly less than the Level 3 setpoint (+10") which caused
certain expected isolations and actuations to occur.
Both reactor recirculation (recirc) pumps
tripped, as expected,
and two of three feedwater heater strings isolated.
The reactor recirc
pumps were subsequently
restarted and reactor water level was restored to normal. All
systems were restored to normal.
The licensee reported the event per 10 CFR 50.72.
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The scram occurred during the performance of a surveillance (SI-145-201) on the feedwater
high water level trip switches,
Unbeknownst to the instrument (1&C) technicians,
at some
time prior to the surveillance, the "C" feedwater high level trip switch had failed in the trip
state.
Thus, when the +54" high level setpoint was exceeded
as a normal course of the
'urveillance
on "A" feedwater channel, a turbine trip occurred since the two-out-of-three
logic was satisfied.
The resultant turbine control valve fast closure resulted in a reactor
scram since power was above 24%.
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Two anomalies were detected on post-trip review:
(1)
Failure of the reactor feed pump (RFP) turbines to trip on the apparent high level trip
'signal.
This was attributed to inadequate contact make-up internal to the Agastat
relay (EGP Series) that performed the trip function.
Upon examination, the contacts
for the turbine trip function were found closed, where as the RFP contacts were'open.
The licensee attributed the RFP turbine trip failure to a design misapplication error.
The failed relay was designed for AC circuit use, but it was erroneously installed in a
DC circuit. This r'esulted in accelerated
thermal aging and premature failure.
The
licensee found the same error in all Unit I feedwater high level switches.
Allof
these relays were replaced with Agastat relays rated for DC voltages.
Following
these replacements,
surveillance testing of all channels was successfully completed.
Similar Unit 2 relays were checked with no misapplication errors detected.
In other systems,
the licensee reviewed all Agastat EGP. series relays having a safety
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related function but no other deficiencies were noted.
Allother non-safety related
Agastat EGP series relays with functions that have possible operational impact (i.e.
turbine trip) were also reviewed.
No incorrect installations were found.
Also
considered
was circuits in which non-safety related.Agastats
shared power supplies
with relays having safety related or operational impact functions.
This was done to
preclude a non-safety related relay failure from affecting the combined power supply
for the circuit. The licensee did not discover any installation errors.
However, some
electrical drawings were found to be in error, and were subsequently
corrected.
(2)
.Unexpected isolation of two non-safety related feedwater heater (FWH) strings.
FWH level instrumentation was checked for all three heater strings following the
event. The licensee believed that the isolations occurred when the FWH level
instrumentation
sensed
flashing in the high pressure FWHs.
Flashing was also
detected in the third string.
However, it was not enough to trip its isolation logic.
Additional minor problems were identified and corrected by the licensee.
No direct
cause for the isolations was found.
The flashing itself was expected.
However, its
magnitude was greater than anticipated.
The inspector responded
to the control room immediately after the scram and observed
operators using procedures
to stabilize the plant in hot shutdown.
Operator response
to the
transient was good. Procedures
were followed and post scram actions were directed. at
stabilizing the plant in hot shutdown.
After the plant was stable, the inspector questioned the
operators about indications they observed during the transient.
In addition, the sequence of
events log generated by the Shift Technical Advisor (STA) was also reviewed.
The inspector
also attended the startup plant operations review committee (PORC) on the following day.
The inspector noted generally good review of the transient by PORC. '
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The inspector questioned various aspects of the event during and after the post scram review,
including the installation error that resulted in an AC relay being installed in a DC circuit.
The licensee was unable to determine the exact cause of the error, but it appeared
to date
from 1982 which was the final licensing phase for Unit 1 and the construction phase for Unit
2.
The inspector considered, this error significant because of its potential generic
implications, along with its long standing nature.
Of particular concern, was the licensee's
apparent inability to detect such an error during-original installation and their continued
inability. to detect this error until it revealed itself during the post scram investigation.
The
inspector noted that the relay nameplate data indicates "120 V 60 Hz" which is clearly for an
AC installation only. The licensee controls implemented to preclude incorrect part
installation were inadequate
since an Agastat relay designed for AC circuit applications was
erroneously installed in a DC circuit. This issue will remain unresolved pending final review
by the licensee and evaluation by the NRC.
(URI 50-387/92-29-01 (Common))
The inspector also noted problems with the feedwater systems response
to an apparent high
level signal.
Technical Specification 3,3.9 requires that all three channels of the
feedwater/main turbine trip system be operable'whenever
the unit is in Operational Condition
1. Two out of three trip systems are needed
to trip the main turbine and the reactor feed
pump turbines whenever reactor water level exceeds +54 inches.
Since the RFP turbines"
failed to trip in response
to an apparent high level signal, their trip system's isolation
function was inoperable.
This isolation failure was caused by incomplete internal contact in
the Agastat relay for "A" FW high level trip function.
The licensee is sending the."A"
Agastat relay off-site for failure analysis. 'The generic implications of the root cause of this
relay failure (RFP trip contacts did not close) will remain unresolved pending evaluation by
the licensee,
and subsequent
review by the NRC.
(URI 50-387/92-29-02 (Common))
2.2.2
Engineered Safety Feature (ESF) System Walkdown - Control Room Emergency
Outside AirSupply System (CREOASS) - Common
The inspector performed an ESF walkdown of the Control Room Emergency Outside Air
Supply System (CREOASS) to independently verify the status of the system.
The inspector
did not identify any major deficiencies during the walkdown. However, the inspector notified
the licensee of deficiencies that required corrective actions.The licensee promptly took or
planned corrective action.
The inspector identified the following deficiencies:
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Several CREOASS filter inspection light bulbs burned out for both A and B filter
trains.
The licensee has written a Work Authorization to correct the deficien'cy.
Loose dog on door to "B" CREOASS filter train charcoal filter.
The licenseo has corrected the deficiency,
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Duct work has holes on either side of A & B CREOASS filter train recirculation air
isolation dampers.
The licensee determined these holes existed to allow boroscopic inspection of the
system.
The licensee decided that these holes did not have a significant detrimental
effect on the system, but, the holes would be plugged.
System engineering found
some additional holes in the CREOASS duct work. The licensee promptly plugged all
the holes with test plugs.
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Dog on a door to CREOASS fan "A" flow control damper not working.
'The licensee has corrected the deficiency.
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Drain valves 083019/083013 packing gland nuts were loose.
The inspector determined the CREOASS system to be properly ahgned m the standby mode
in accordance with appropriate procedures
and able to perform its intended safety function.
Excepting the deficiencies noted, the inspector concluded the licensee maintained the system
in good condition.
2.2.3
Hourly Fire Watch Records Review
The inspector reviewed hourly fire watch records for the month of September
1992.
Site
contract personnel perform the subject roving fire watch rounds.
Contract personnel
completed all fire watch rounds for the month of September.
The inspector found that no
hourly fire watches were missed, but noted that two individuals failed to perform a round
properly.
The contractor supervisor and foremen routinely perform random field observations of fire
watches to ensure proper performance of fire watch rounds.
On September
10, fire watch
supervisors,
on separate
occasions,
observed two individuals improperly performing fire
watch rounds in the "A" Emergency Diesel Generator Bay. Allelevations in the diesel
generator bay are considered within the fire zone.
Accordingly, fire watches are required to
physically check the lower 660'levation.
This expectation was clearly and accurately
communicated to fire watch personnel through training, the fire watch bulletin board and
shift turnover.
During September,
contractor supervision observed that both the individuals failed to
physically inspect the 660'levation.
Supervisors later questioned
the individuals on whether
they completed the round, specifically the 660'levation.
One individual admitted he did not
go down to the 660'levation and received a five day suspension without pay.
The
other'ndividual
maintained that he completed the round even after repeated questioning.
The
'ndividual was subsequently
terminated.
The supervisors
descended
to the 660'levation and
performed the required check after they noted that each fire watch missed it.
Contract supervision convened a Review Board Assembly to review all the circumstances
concerning the performance of the particular round.
PP&L supervision and one of the
individuals participated in the meeting.
Following the review board, the site supervisor
decided that the employee would be terminated based on the employee lying about
completing a round.
PP&L supervisors present at the Review Board Assembly endorsed
the
'decision.
The inspector concluded that based on a review of records and discussions
that the licensee
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. did not miss any required fire watch.
The contractor's disciplinary action concerning the
individuals appeared
commensurate
to the circumstances.
The inspector had no further
questions.
2.2.4
Inoperable "B" High Flow Isolation Channel for the Unit 2 Reactor Water
Cleanup System
On November 15; 1992, operators noted a significant decrease
in the reading of the "B"
Reactor Water Cleanup (RWCU) High Flow channel during a routine surveillance.
Although
the associated
instrument (PDIS-G33-2N044B) met the channel check acceptance
criteria, the
licensee initiated an investigation.
At 11:20 a.m., November 17, the channel was taken out
of service to determine the cause of the apparent flow reduction and Technical Specification (TS) 3.3.2 was entered.
At 1:10 p.m,, the channel was confirmed to be inoperable and the
licensee concluded that the instrument could not be repaired in the time allotted by TS 3.3,2.
Therefore, the RWCU system was shutdown and isolated.
The licensee requested
a
temporary waiver of compliance to permit operation of the RWCU system for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to
allow time to troubleshoot and repair the defective high flow instrument.
The licensee
proposed that continued operation was safe and justifiable due to the operability of the "A"
RWCU High Flow isolation instrument,
as well as the other diverse and redundant RWCU
line break detection logic required by Technical Specification 3.3.2.
The NRC subsequently
approved the waiver on November 18.
The licensee performed troubleshooting over the next three days but was unable to identify
the cause of failure.
Because of the lack of a clearly identifiable cause,
an extension of the
original waiver was requested.
The NRC questioned the licensee on their intentions, since,
ifthis extension were to expire without a root cause being determined,
an additional (third)
extension would be required.
After further consideration,
the licensee modified their request
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to seek NRC approval to operate for the remainder of the fuel cycle with "B" RWCU high
flow channel inoperable but with a full set of compensatory
measures
in place.
The modified
waiver request was submitted on November 20.
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During continued licensee review and discussion with the NRC, a vulnerability was
discovered in the licensee's compensatory
measures.
Piping that runs from the containment
wall through. the pipe routing areas to the RWCU rooms was not adequately monitored for
line break, nor was the deficiency identified in the licensee's November 20 submittal.
Accordingly, NRC determined that the basis of the waiver request was insufficient.
Subsequently,
the licensee reentered TS 3.3.2 and began to make plans to isolate RWCU.
The licensee subsequently
determined that the RWCU high demineralizer temperature
'instrument could be used as an alternative line-break detector device.
The licensee noted that
a leak in the pipe routing area would cause a flow increase that would exceed the various
RWCU heat exchangers
ability to remove an adequate amount of sensible heat from the
'rocess
fluid. This would result in a system isolation on high temperature.
The licensee
determined that-this instrument, altho'ugh not part of the isolation logic, but powered from a
safety grade power supply, would provide an acceptable alternative for the inoperable high
flow channel.
Accordingly, the
licensee reinitiated their waiver request to effectively substitute the RWCU
high temperature isolation function in place of the "B" High Flow Channel isolation function.
The NRC agreed with this approach in a November 25 response
to the licensee,
as long as,
all TS 3.3.2 requirements
(surveillance, operability, action times, etc.) were applied.
The
licensee agreed to these restrictions, and to submit a formal TS amendment
request on/or
before November 30 to reflect these limitations and conditions for the remainder of the
operating cycle.
The.licensee's
submittal is currently being reviewed by NRC.
The inspector noted a number of weaknesses
relative to this matter.
Specifically, it appeared
, that'the licensee did not fully review all aspects of the RWCU leak detection system design
and consider them in their formal requests.
The licensee has also recognized weakness with.
their interaction with NRC on this matter and has formed an Event Review Team (ERT) to
fully evaluate their performance.
NRC findings on this matter will remain unresolved
pending ERT review and NRC evaluation of their findings.
(URI 50-387/92-29-03)
3.
RADIOLOGICALCONTROLS
3.1
Inspection Activities
PP&L's compliance with the radiological protection program was verified on a periodic
basis.
These inspection activities were conducted in accordance with NRC inspection
procedure 71707.
3.2
Inspection Findings
Observations of radiological controls during maintenance activities and plant tours indicated
that workers generally obeyed postings and Radiation Work Permit requirements.
Findings
are discussed
in the following sections.
3.2.1
"B" AuxiliaryBoiler Contamination
On November 12, a routine effluent sample of the "B" auxiliary boiler showed contamination
of the auxiliary steam.
The sample contained nitrogen-13 and fluorine-18.
This combined
with the absence of activation products such as cobalt-60 and manganese-54
indicated
contammation of the auxiliary steam system with main steam.
Following the identification of
contamination, Unit 1 scrammed
due to a failed Agastat relay.
At the time, Unit 2 was in
cold shutdown and Unit 1 was operating.
The licensee documented
this occurrence in SOOR
1-92-352.
Since Unit 2 was shutdown at the time and Unit 1 had scrammed,
the source of contaminated
steam was removed.
A chemistry sample showed decreasing activity on November 13.
A
sample from the auxiliary boiler deaerator vent on the radwaste building roof indicated
xenon-135 activity. The samples from the boiler and the deaerator vent indicated that the
'ormally
uncontaminated
auxiliary boiler system was subjected to leakage from the main
steam system resulting in a small but uncontrolled and unmonitored release of noble gas.
PP&L prepared
a Plant Operations Review Committee (PORC) approved safety evaluation to
allow temporary operation of the auxiliary boiler as allowed by guidance set forth in NRC
I&EBulletin 80-10, "Contamination of Non-radioactive Systems and resulting Potential
Unmonitored, Uncontrolled Release to the Environment".
Plant management
decided to
operate with.contamination to allow the start up of both units, as well as to facilitate location
. of the exact source of the leak.
The safety evaluation determined that no unreviewed safety
question existed and required no change to Technical Specifications.
The chemistry
department concluded that since the deaerator removes air and non-condensible
gasses
(air,
oxygen, xenons, kryptons) and discharges
them through the vent, the fission product gasses
from the discharged
steam would be released via the vent.
Using conservative as'sumptions,
the licensee calculated the release rate from the vent to be 7.37 E-3 microcuries/second.
Typical Lower Limitof detection (LLD) release rates from the five normally monitored vents
are 50-70'microcuries/second.
This represents
a small fraction of the value where any
routine releases
above the minimum detection level would be reported.
The licensee also calculated the maximum total body dose measured
at the site boundary for
the given noble gas source to 2.12 E-5 mrad based on dose due to noble gases
released
as
gaseous effluents.
The Technical Specification
quarterly limitfor gamma radiation due to
noble gases released in gaseous
effluents is 5 mrad.
To further ensure minimal doses,
the
licensee safety evaluation required shutdown and cooldown of the auxiliary boiler ifthe
offgas pretreatment rate exceeded
1000 uci/sec.
The licensee performed an investigation to find the source of leakage.
System engineering
determined that the source was Unit 1 main steam supply to the steam jet air ejector (SJAE).
Steam was leaking past motor operated valve HV10752, which was closed, and check valve
107027.
The remaining flow path contained steam trap ST10702, which drains to the
Auxiliary Boiler Deaerator.
The licensee secured
the leak by closing and administratively controlling manual valve
HV107077.
The leak was verified to have stopped based on a drop in pipe temperature.
Following the start up of both units the licensee issued work authorizations to inspect/repair
the leaky valves.
The licensee has preliminary determined that actions to prevent recurrence
include revising the system check list and operating procedure to have manual HV107077
closed unless auxiliary steam is required to supply SJAE.
System engmeering has,proposed
an enhancement
to route steam trap ST10702 drains to the main condenser
instead of the
auxiliary boiler deaerator.
PP&L willinclude the activities of released
radionuclides in the
next Semi-Annual Effluents Report.
The inspector concluded that the licensee promptly identified and adequately determined the
cause of the auxiliary boiler contamination.
The sampling that promptly identified the
contamination was part of sampling program that was established in response
to NRC I&E-
Bulletin 80-10 "Contamination of Non-radioactive Systems and Resulting Potential
Unmonitored, Uncontrolled Release to the Environment".
The licensee properly performed a
safety evaluation to allow continued operation of the system in accordance with the guidance
set forth in the Bulletin 80-10.
Radiological consequences
were properly and conservatively
assessed.
The inspector determined that the short-term corrective actions were prompt and
adequate.
The long-term corrective actions are still in the planning stage and not yet
finalized.
Licensee immediate response
to this event was considered
adequate,
however, this
was the third such occurrence of auxiliary boiler contamination from the same source.
SOOR's 1-88-158 (dated May 23, 1988) and 1-89-370 (dated December
12, 1989)
documented two previous occurrences.
All three auxiliary boiler contaminations were from
essentially the same backleakage path.
Following the 1988 contamination, maintenance
repaired the leaky valves in January
1989:
The same valves leaked again by December
1989, and maintenance
once again repaired the valves.
Subsequently,
the valves leaked
again in November 1992, resulting in this most recent contamination of the auxiliary boiler.
The licensee resolution of the event was still in progress at the end of the period.
This item
will remain unresolved pending further review and determination of adequacy by the
inspector regarding final corrective actions.
(URI 92-29-04)
3.2.2
Highly Concentrated Radiation Beams in the Drywell
The inspector performed a follow up inspection on the susceptibility of either Susquehanna
unit to highly concentrated
radiation beams similar to those observed at the Limerick Nuclear
Generating Station (LNGS). During July 7-9, 1992, at LNGS, various workers made a
number of entries into the drywell to repair a damaged
main steam sample valve.
The repair
10
attempts were made to restore the valve to an operable status as a containment isolation
valve.
After the entries were completed,
a highly concentrated
radioactive beam was
discovered in an adjacent area where work was performed.
The pre-defined work area was
well surveyed.
However, an adjacent work area that was accessed
by climbing over a
handrail and other equipment was not adequately
surveyed prior to work. The work
performed at the LNGS was performed with reactor operating at a low power (5-8%).
The inspector questioned
the licensee on their potential susceptibility to these beams and their
likelihood of making containment entries at power.
The licensee stated that no entries have
been made into either drywell since each unit went into commercial operation (Unit 1, 1982;
Unit 2, 1985).
Certain low power entries were made during pre-operational
testing to
perform required neutron surveys.
These entries were strictly controlled.
The licensee
intends to delete a provision in AD-QA-309, the Primary Containment Access and Control
procedure that currently permits power entries with superintendent
approval (PCAF 1-92-
1294).
This change also added a requirement to ensure that the reactor was shutdown prior
to initial entry.
To compare shielding configurations between LNGS and SSES, the inspector reviewed the
results of radiation surveys taken approximately one month into the fall 1992 Unit 2 refueling
outage.
The highest gamma radiation levels were inside the biological shield at 12 R/hr on
contact with the bottom of the N-16 nozzle.
General area radiation levels at the biological
shield were 100 mR/hr.
No high dose rate streaming was detected.
Neutron surveys were
not performed since the reactor was shut down.
The inspector compared surveys performed
on October 7 and 8, 1992 and noted good correlation between the results.
The inspector found that the licensee actions in changing the containment entry procedure to
be strong and conservative.
In addition, recent surveys showed no unusual radiation
streaming.
4.
MAINTENANCE/SURVEILLANCE
4.1
Maintenance and Surveillance Inspection Activity
On a sampling basis, the inspector observed and/or reviewed selected surveillance and
maintenance activities to ensure that specific programmatic elements described below were
being met.
Details of this review are documented in the follow'ing sections.
4.2
Maintenance Observations
The inspector observed and/or reviewed selected maintenance activities to determine that the
work was conducted in accordance with approved procedures,
regulatory guides, Technical
Specifications,
and industry codes or standards.
The following items were considered,
as
applicable, during this review:
Limiting Conditions for Operation were met while
components or systems were removed from service; required administrative approvals were
0
11
obtained prior to initiating the work; activities were accomplished
using approved procedures
and quality control hold points were established
where required; functional testing was
performed'prior to declaring the'involved component(s) operable; activities were
accomplished by qualified personnel; radiological controls were implemented; fire protection
controls were implemented; and the equipment was verified to be properly returned to
service.
These observations and/or reviews included:
WA 24798, Fuel Oil.Investigation on "A" Emergency Diesel Generator,
dated
November 23.
WA 27645, Suppression
Chamber Atmospheric Temperature Indication Division 2
Investigation, dated December 3.
WA 26909,
Reactor Core Isolation Cooling Barometric Condenser High Level
Switch Replacement,
dated December 22.
WA 20297,'Standby Liquid Control Nitrogen Accumulator Pressure
Check, dated
December'22.
4.3
SurveBlance Observations
The inspector observed and/or reviewed the following surveillance tests to determine that the
following criteria, ifapplicable to the specific test, were met:
the test conformed to
Technical Specification requirements;
administrative approvals and tagouts were obtained
before initiating the surveillance; testing 'was accomplished by qualified personnel in
accordance with an approved procedure;
test instrumentation was calibrated; Limiting
Conditions for Operations were met; test data was accurate and complete; removal and
restoration of the affected components
was properly accomplished;
test results met Technical
Specification and procedural requirements;
deficiencies noted were reviewed and
appropriately resolved; and the surveillance was completed at the required frequency.
These observations and/or reviews included:
SI-258-301, Quantity Calibration of Drywell Pressure (Primary Containment) High
Pressure
Channels PSH-C72-2N002 A, B, C, D, dated December
16, 1992.
SI-156-203, Channel Functional Test of SCRAM DISC Volume (SDV) High-Water
Level Channels LSH-C12-IN013 E & G, dated December
18, 1992.
SO-024-001A, Monthly Operability Test of the "A" Emergency Diesel- Generator,
dated December 21, 1992.
'2
4.4'nspection
Findings
The inspector reviewed the listed maintenance
and surveillance activities.
The review noted
that work was properly released before its commencement;
that systems and components
were properly tested before being returned to service and that surveillance and maintenance
activities were conducted properly by qualified personnel.
'Where questionable
issues arose,
the inspector verified that the licensee took the appropriate action before system/component
operability was declared.
The inspectors had no further questions on the listed activities.
5.
5;1
Inspection Activity
The inspector reviewed licensee event notifications and reporting requirements for events that
could have required entry into the emergency plan.
5.2
Inspection Findings
No events were identified that required emergency plan entry. No inadequacies
were
identified.
6.
SECURITY
6.1
Inspection Activity
PP&L's implementation of the physical security program was verified on a periodic basis,
including the adequacy of staffing, entry control, alarm stations,
and physical boundaries.
These inspection activities were conducted in accordance with NRC inspection procedure
71707.
6.2
Inspection Findings
The inspector reviewed access
and egress controls throughout the period.
No significant
observations were made.
7.
ENGINEERING/TECHNICALSUPPORT
7.1
Inspection Activity
The inspector periodically reviewed engineering and technical support activities during this
inspection period.
The. on-site Nuclear Systems Engineering (NSE) organization, along with
Nuclear Technology (NPE) in Allentown, provided engineering resolution for problems
during the inspection period.
NSE generally addressed
the short-term resolution of
engineering problems; and interfaced with the Nuclear Modifications organization to schedule
13
modifications and design changes,
as appropriate,
to provide long-term corrective action.
The inspector verified that problem resolutions were thorough and directed at preventing
recurrences,
In,addition, the inspector reviewed short-term actions to ensure that they
provided reasonable
assurance
that safe operation could be maintained.
7.2
Inspection Findings
7.2.1
Diesel Generator Automatic Start Due to Agastat Relay Failure
On November 13, at 11:35 a.m., the "E" Diesel Generator (DG) automatically started in the
emergency run mode.
No testing or maintenance
was being performed at the time.
The "E"
DG had been previously substituted for the "A" DG.
The licensee investigated and verified
that no valid automatic (auto) start condition existed.
The "E" DG was then shutdown.
The
DG auto start was reported,
as required, as an ESF actuation.
The licensee investigated and found that a normally energized Agastat (EGP series) relay
deenergized
causing the "E" DG auto start,
This relay (4ESS1) and its Unit 2 counterpart
(4ESS2) were replaced.
Post-maintenance
testing and an operability run was satisfactorily
performed.
The "E" DG was then returned to an operable status in its standby condition.
The inspector observed portions of the replacement relay installation and questioned various
licensee personnel on the event.
The inspector observed maintenance
personnel bench test
the replacement relay.
The licensee tested all of the contacts to verify less than one ohm
resistance
between them.
Some of the contacts exhibited higher than expected resistance
(20-
70 ohms) which indicate the contact faces had oxidized.
To remove the oxidation, these high
resistance
contacts were first electrically burnished,
and, ifnecessary,
mechanically
burnished to achieve the one ohm target.
The relay was then installed into the "E" DG.
The
failed relay was removed and held pending shipment offsite for failure analysis.
The
inspector noted that the maintenance
personnel were very knowledgeable and followed their
work plan.
The failed Agastat was approximately seven months old at the time of failure.
The licensee is planning on sending the failed relay to an independent laboratory to determine
the specific failure mechanism.
The inspector reviewed the licensee's preventative maintenance program for periodic Agastat
relay replacement
and found that it only specifically addressed
safety-related relays in a harsh
environment as a part of their equipment qualification (EQ) program,
Non-EQ safety-related
relays had no periodic replacement interval.
The inspector questioned
the licensee on their
review of NRC Information Notice (IN) 84-20, Service Life of Relays in Safety-Related
Systems since it recommended
Agastat relay replacement on definite intervals.
This IN was
issued to inform industry of earlier than anticipated end-of-service-life failures for Agastat
relays at the Grand Gulf Nuclear Station.
As a result of these failures, Amerace (the parent
company of Agastat relays) and General Electric (GE), performed additional testing and
concluded that the qualified life for all Agastat GP series relays (GP, FGP and EGPD
series), that are operated in a normally energized
state was 4.5 years.
Normally deenergized
14
V
relays were to have a 10 year lifetime. In the licensee's review of this IN, they disagreed.
with the 4.5 year lifetime since they believed it was based on an interpolation of an
~ Underwriter's Lab (UL) non-test based lifetime while their lifetime figures were based on
extrapolation of testing on melamine breaker material.
Thus, they established
a 10 year
lifetime for all Agastat GP relays not addressed
by their EQ program.
Recently, the'licensee
changed their service life to 4.5 years as a result of degradations
seen due to thermal aging.
'n
addition, in a November 9, 1992 memoranda (PLI-72840), an Agastat replacement
program was initiated.
The licensee identified the need to replace 183 Agastat relays for
safety related-active and nonsafety related-critical (to plant operations) applications.
This
replacement
schedule omitted diesel generators
Agastats which willbe addressed
separately.
The inspector noted that the licensee recently established
service lifetimes for certain non-EQ
safety related Agastats.
However, the inspector questioned the licensee's delay in
recognizing the need for such a program when it was clearly an identified priority in IE
Bulletin 84-02, HFA Relays, and Information Notice 84-20, Service Life for Safety Related
Relays.
Over the past nine years, since issuance of the IN, there have been numerous
Agastat relay failures due to thermal aging.
For the most part, the licensee has treated these
failures as isolated occurrences.
These generic communications emphasized
the need for the
licensee to establish service lifetimes for various safety related relays.
The licensee has
agreed to track replacement of the 183 safety related relays (SOOR 1-92-345) and will
review the need for the establishment of additional service lifetimes for other safety related
relays.
The inspector willcontinue to monitor the licensee's relay replacement activities.
The inspector had no further questions at this time.
8.
SAFETY ASSESSMENT/QUALITY VERIFICATION
8.1
Licensee Event Reports
The inspector reviewed LERs submitted to the NRC office to verify that details of the event
were clearly reported, inclu'ding the accuracy of the description of the cause and the
adequacy of corrective action.
The inspector determined whether further information was
required from the licensee, whether generic implications were involved, and whether the
event warranted onsite followup. The following LERs were reviewed:
.@nit
1
92-017-00
"Reactor Scram When Main Turbine Tripped Due to Failed Relay in
Feedwater High Level Trip Logic"
On November 12, 1992, with Unit 1 operating at 100%, a reactor protection system
actuation occurred when the main turbine tripped during surveillance testing on the feedwater
control system.
The turbine control valves closed and automatic reactor scram occurred per
'15
design.
The licensee determined the turbine trip was caused by a failed AGASTAT relay in
the Feedwater "C" High Level Turbine Trip Channel coincident with surveillance testing of
the Reactor Feedwater "A" High Level Turbine Trip Channel.
Section 2.2.1 pertains.
r
92-048-00-
"Unplanned ESF Actuations - "E" Diesel Generator Automatic Start"
On November 12, 1992, an unplanned ESF actuation o'ccurred when the "E" Emergency
Diesel Generator (EDG) automatically started in the emergency run mode.
The
licensee'etermined
the cause was failure of a normally energized AGASTAT relay in EDG's
emergency start circuit.
Section 7.2.1 pertains.
Unit 2
92-005-00
"Residual Heat Removal Shutdown Cooling Isolation - Unplanned ESF
Actuation"
On October 26, 1992, at 10:50 a.m., with Unit 2 in Condition 4, an unplanned ESF
actuation occurred during modificatio'n and testing of the containment isolation system.
The
unplanned ESF actuation occurred while a technician was attempting to land a lead in the
containment isolation logic with adjacent portions of the system energized.
The lead was
inadvertently grounded when it slipped out of the technicians hand which resulted in blowing
a fuse in the logic scheme.
The loss of logic power deenergized
a relay which caused RHR
shutdown cooling inboard isolation valve and the RHR injection valve to close causing the
RHR pump to trip.
Operations personnel followed the procedure for Loss of Shutdown
Cooling.
The subject lead was landed and the blown fuse replaced.
The licensee restored
shutdown cooling at 11:40 a.m..
Reactor'oolant temperature
increased 5'F while shutdown
cooling was lost.
The licensee deter'mined the cause of the event was inadequate accessibility
making the task physically difficultto perform.
The licensee is evaluating the work
authorization program with regard to, working energized
schemes
in certain plant systems
depending on specific plant conditions.
No significant observations
were made.
8.2
.Open Items
8.2.1
(Closed) NC4 50-387/90-08-01, Inadequate Corrective Actions To Prevent
Recurring Late. Event NotiTications To The NRC
On April 17, 1990 the control room indication for HD-17502A, a secondary containment
heating, air conditioning, and ventilation (HVAC) isolation damper was lost.
The operators
decided that ifthe damper was inoperable, it would be a degradation in secondary
containment integrity and therefore entered the applicable 4-hour LCO.
Personnel
dispatched
to investigate found that the normally open damper had cycled to its closed position.
16
Instrumentation and Control (1&C) technicians were called to trouble shoot and repair the
damper.. After one failed repair attempt, the damper was successfully returned to service on
April 18.
During a post event review on April23, the licensee determined the HVAC isolation damper
cycling closed constituted an ESF actuation.
PP&L then made a "4-hour" NRC notification
for the ESF actuation,"5 days and 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br /> after the event.
This was the third instance of
late licensee identification and NRC notification of ESF actuations in eight months.
The
licensee's corrective actions following late notifications in August and September
1989 were
not effective and did not preclude the third instance of late NRC notification. The NRC
documented
this violation in Inspection Report 50-387/90-08.
f
The licensee's
response
to the violation admitted the three ESF actuations were not reported
within the time frame required by 10 CFR 50.72(b)(2)(ii). However, PP&L stated their
methodology for classifying a failure that cycles an ESF component,
as a reportable ESF
actuation, is extremely conservative.
The HVAC damper closed because of a component
failure (the damper's solenoid valve) and not because of a valid logic signal.
The licensee
also stated that inconsistent application of their methodology for classifying failures was the
reason for the violation. As corrective action PP&L developed formal guidance to assist
~
~
operators in evaluating events for reportability as unplanned ESF actuations.
In addition,
'
licensee personnel have received training on the use of this guidance.
F
The inspector reviewed the licensee's
response
to the violation and the ESF actuation
reportability guidelines which the licensee approved on August 21, 1990.
The inspector
identified no problems with either the response or the guidelines.
The inspector noted that
since PP&L started using the reportability guidelines, they have become more consistent in
reporting ESF actuations.
The inspector concluded that the licensee has taken appropriate
actions in response
to the violation and that this item is closed.
9.
MANAGEMENTAND EXIT MEETINGS
9.1
Resident Exit and Periodic Meetings
The inspector discussed
the findings of this inspection with station management
throughout
and at the conclusion of the inspection period.
Based on NRC Region I review of this report
and discussions
held with licensee representatives,
it was determined that this report does not
contain information subject to 10 CFR 2.790 restrictions.
17
9.2
PP&L Emergency Protective Guidelines Meeting
On December
18, 1992, PP&L and NRC management
met in the NRC Region I office to
discuss differences between PP&L's latest revision of emergency operating procedures
(EOPs) and the BWR owners group (BWROG) Emergency Protective Guidelines (EPG),
Revision 4.
Attachment 2 is the list of meeting attendees
and Attachment 3 is a copy of the
slides used by PP&L during the meeting.
PP&L plans to implement their new EOPs on December 31, 1992.
The latest revisions are
based on the BWROG EPG, Revision 4, and the Susquehanna
Individual Plant Evaluation.
18
ATTACHMENT'1
Ab reviation List
ANSI
CFR
CIG
DX
ERT
IERP
JIO
LCO
LER
-LOOP
NQA
NRC
NSE
- Administrative Procedure
- Automatic Depressurization
System
- American Nuclear Standards Institute
- American Society of Mechanical Engineers
- Containment Atmosphere Control
- Code of Federal Regulations
- Containment Instrument Gas
- Control Rod Drive Mechanism
- Control Room Emergency Outside Air Supply System
- Diesel Generator
- Direct Expansion
- Emergency Core Cooling System
- Engineering Discrepancy Report
- Electrical Protection Assembly
- Environmental Qualification
- Event Review Team
- Engineered
Safety Features
- Emergency Service Water
- Engineering Work Request
- Fuel Oil
- Final Safety Analysis Report
- Heating, Ventilation, and Air Conditioning
- Industry Event Review Program
- Instrumentation and Control
- Justifications for Interim Operation
- Limiting Condition for Operation
- Licensee Event Report
- Local Leak Rate Test
- Loss of Coolant Accident
- Non Conformance Report
- Nuclear Department Instruction
- Nuclear Plant Engineering
- Nuclear Plant Operator
- Nuclear Quality Assurance
- Nuclear Regulatory Commission
- Nuclear Systems Engineering
19
PC
'CIS
PMR
PSID
~
'SGTS
SOOR
SPING
TS
WA
- Open Item
- Out-of-Service
- Protective Clothing
- Primary Containment Isolation System
- Plant Modification Request
- Plant Operations Review Committee
- Pounds Per Square Inch Differential
- Quality Assurance
- Reactor Building
- Reactor Building Closed Cooling Water
- Reactor Core Isolation Cooling
- Regulatory Guide
- Residual Heat Removal Service Water
- Standby Gas Treatment System
- Surveillance Procedure,
Instrumentation and Control
- Steam Jet Air Ejector-
- Surveillance Procedure,
Operations
- Significant Operating Occurrence Report
- Safety Parameter Display System
- Sample Particulate, Iodine, and Noble Gas
- Technical Specifications
- Work Authorization
20
ATl'ACHMENT2
MANAGEMENTMEETING TO DISCUSS SUSQUEHANNA
DIFFERENCES RELATIVETHE BWROG EPG, REVISION 4
Attendees on December
18, 1992
Penns
lvania Power and Li ht
m an
G. Stanley, Superintendent of Plant
G. Jones, Manager, Nuclear Engineering
J. Kenny, Supervisor, Nuclear Licensing
R. Peal, Supervisor, Nuclear Compliance
G. Butler, Supervisor,
Systems Analysis
A. Fitch, Supervisor,
Operations Training
R. Wehry, Compliance Engineer
R. Lemgel, System Engineer
M. Chaiko, Project Engineer
C. Kickielka, Senior Project Engineer
Nuclear Re ulato
Commission
L. Bettenhausen,
Chief, Operations Branch, Division of Reactor Safety (DRS)
E, Wenzinger, Chief, Reactor Projects Branch 2, Division of Reactor Projects (DRP)
C. Miller, Project Director, PD I-2, Office of Nuclear Reactor Regulation (NRR)
J. White, Chief, Reactor Projects Section 2A, DRP
R. Conte, Chief, BWR Section, DRS
T. Walker, Senior Operations Engineer, DRS
D. Florek, Senior Operations Engineer, DRS
C. Sisco, Operations Engineer, DRS
B. McDermott, Reactor Engineer, DRP
Qther
D. Ney, State of Pennsylvania,
DER, Nuclear Engineer
ATTACHMENT 3
INTRODUCTION
II ~
III. HOW WE ARE IMPLEMENTINGREV 4 EOPS.
DIFFERENCES BETWEEN SSES AND OTHER
SITES.
HISTORY
FIRST EOPS
PROSE.
AUGUST, '1985
REV 3 FLOWCHARTS
DECEMBER, t 992
REV 4 FLOWCHARTS
OPERATOR
REV.
3
EOP'S
'IPE
DESIGN
INP UTS
SYSTEM
ENGINEERS
AN ALYZE
8c
IDENTIFY RISKS
OPTIONS
TO
MINlMl2 E
R ISKS
EOP'S
STRATEGY
TRAINING
PLANT
MODS
EQUIP MENT
OUTAGES
WRITE PROCEDURES
REV,IEW
TRAINING
VALIDATION
REVISION
IMPLEMENT
IMPLEMENTATlON
SCHEDULE
1 2/31/92
DEVlATlONS
1 PERFORMANCE
4 CONTENT
PERFORMANCE
PPSL'S APPROACH IS DELIBERATE,
METHODICALADHERENCE TO EOP
FLOWCHARTS
ENHANCES PROBABILITY FOR, ERROR-FREE
PERFORMANCE
REDUCES NEED TO RECOVER FROM
PERFORMANCE ERRORS
TIME CRITICAL
VS
OBSERVED PARAMETERS
EOP'S ARE PART OF RISK MANAGEMENT
~
BASED ON BWROG EPG REV 4 AND OUR IPE
REV 4 EOPS
1 2/31/92
REVIEWED.
TRAINED
VALIDATED
e
DEVIATIONS
FEW
MINOR IN NATURE
IIVlPROVE OUR PLANT SPECIFIC RISK
PROFILE
PPRL EOP PROGRAM
SUSQUEHANNA SPECIFIC STRATEGY
~
RISK ASSESSMENT INFLUENCED EOPS
4
REVIEWS CONDUCTED IN TWO PROGRAMS:
EOP PREPARATION
IPE REVIEWS
~
ATWS EVENT STUDY GENERATED
DIFFERENCES:
SSES ANALYSES SHOW POOR REA'CTOR
BEHAVIOR FOR:
LOW WATER I EVEL OPERATION
LOW PRESSURE OPERATION
PPRL EOP PROGRAM
SSES'SPECIFIC
EOP DIFFERENCES
4
USE OF HPCI DURING DEPRESSURIZATION
REDUCED OPERATOR CHALLENGE
IMP ROVED H PC I RELIABILITYTHRO UG H
TRANS lENT
PREFERRED SOURCE OF MAKEUP
MINIMALINCREASE IN CONTAINMENT
HEATING
J
ATWS STRATEGY
PPRL EOP PROGRAIVI
SPECIFIC EOP DIFFERENCES
0
REACTOR WATER LEVEL MAINTAINED
BETWEEN -110" AND -80" (TAFI -161")
QUESTIONABLE STABILITYREGION-
AVOIDED
WATER LEVEL CONTROL IMPROVED
ENHANCED BORON MIXING
ENHANCED WATER LEVEL INDICATION
IN CR
CONSISTENT DIRECTION
INCREASED CONTAINMENTHEAT
LOADS
ATWS STRATEGY
PPRL EOP PROGRAIVl
SPECIFIC EOP DIFFERENCES
RPV DEPRESSURIZATION NOT FORCED BY
HEAT CAPACITY TEMPERATURE LIMIT
(HCTL) APPROACH
AVOIDS LOW PRESSURE REGION
REDUCED CONTAINMENTTHREAT FOR
MOST SCENARIOS
INCREASED CONTAINMENTTHREAT FOR
ONE SCENARIO
ATWS STRATEGY
ppg L Eap PROGRAlvl
SPECIFIC EOP DIFFERENCES
4,
HCTL IS NOT RESTRAINED BY SUPPRESSION
POOL DESIGN TEMPERATURE
HIGHER TEMPERATURE LIMITS REFLECT
LIMITINGCONTAINMENTPRESSURE AT
'ND
OF DEPRESSURIZATION.
SRV QUENCHER LOADS HAVE BEEN
FOUND TO ACTUALLYDECREASE WITH
INCREASING POOL TEMPERATURE.
PPRL EOP PROGRAM
SUMMARY
~
GENERALL'Y CONSISTENT WITH EPG REV 4
LIMITEDAREAS OF DIFFERENCE
ATWS STRATEGY
HCTL BASIS
~
EACH DIFFERENCE THOROUGHLY ANALYZED
~
PPBcL CONTINUES TO IMPROVE ITS EOP'S
SUIVllVIARY
1
t
~
EOP'S ARE PART OF RISK.MANAGEMENT
t
e
BASED ON BWROG EPG'REV 4 AND OUR IPE
9
REV 4 EOPS
1 2/31/92
REVIEWED
TRAINED
VALIDATED
DEVIATIONS
FEW
MINOR IN NATURE
IMPROVE OUR PLANT SPECIFIC RISK
PROFILE