ML15224A687
| ML15224A687 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 06/15/1990 |
| From: | Shymlock M, Skinner P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML15224A685 | List: |
| References | |
| 50-269-90-16, 50-270-90-16, 50-287-90-16, NUDOCS 9006290212 | |
| Download: ML15224A687 (29) | |
See also: IR 05000269/1990016
Text
UNITED STATES
NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, N.W.
ATLANTA, GEORGIA 30323
Report Nos.:
50-269/90-16, 50-270/90-16 AND 50-287/90-16
Licensee:
Duke Power Company
422 South Church Street
Charlotte, NC
28242
Docket Nos.:
50-269, 50-270 and 50-287
License Nos.:
Facility Name:
Oconee Units 1, 2 and 3
Inspection Conducted:
May 17 -
22, 1990
Team Leader:
6/ 2p-/'
7
c
P. H. Skinner
Date Signed
Senior Resident In pector, Oconee
Team Members: N. Economos, Materials Inspector, DRS
F. Wright, Radiation Specialists, DRSS
N. Merriweather, Electrical Plant Systems Inspector, DRS
Approved by:
d
-
<
-d
w--.--
6
M. B. ShymWk,-Chief
Date Signed
Reactor Projects Section 3A
Division of Reactor Projects
TABLE OF CONTENTS
Executive Summary
1. General Description ....................................... 1
2. Description of Events .....................................
1
A.
General ...........................................
1
B. Chronological Sequence ............................ 3
3.
Radiological Review ....................................... 5
A.
Initial Notification and RP Response ..............
5
B. Scope of Spill .................................... 6
1. Inside Auxiliary Building ................
6
2. Outside Auxiliary Building ...............
7
C. Recovery and Decontamination Efforts ..............
8
D.
Evaluation of Licensee Radiological Protection
Efforts .......................................
9
4. Materials Review .......................................... 9
A. Mechanical ........................................
9
B.
Electrical ........................................ 10
5. Operational Review ....................................... 11
6. Exit
.................................................... 12
7. Attachments ............................................. 13
A.
List of Acronyms and Abbreviations ................ 13
B. List of Persons Contacted ........................ 14
C.
Initial Contamination Areas ...................... 15
8. Table 1 & 2 -
Electrical Cabinets Inspected ................. 16
9. Figures 1 through 9
0
Executive Summary
On May 17, 1990 while performing component verification on the reactor
vessel following fuel loading, the Unit 1 and 2 SFP overflowed resulting
in various areas of the Auxiliary Building being contaminated.
In
addition, an area outside the Auxiliary Building adjacent to the Fuel
Receiving Bay and the Unit 2 West Penetration room exterior access door
became contaminated. The licensee operations personnel took quick actions
to stop the spill.
Health Physics personnel assisted by various other
site personnel took prompt action to identify areas contaminated.
The
spread of contamination was controlled and the followup cleanup process
was well organized and effective.
This event was caused by performing a procedural step out of sequence in
the transfer canal draining procedure.
Inspector review indicated that
taking the step out of sequence changed the intent of the procedure and
resulted in a violation for failure to operate in accordance with approved
procedures.
0
0II
0I
1. General Description Of Spent Fuel Cooling System (See Figure 1)
The SF consist of a common storage pool and three cooling trains (pumps
and heat exchanger) which serve both Units 1 and 2.
These trains are
connected in parallel loops. The number of loops in use depends upon the
heat.load in the SFP.
The SF system also contains two filters and a
demineralizer.
The system under normal operation takes suction from a
high point in the pool and discharges to both a high point and a low point
in the pool to keep solids in suspension. The system is designed to limit
pool temperature to 205 degrees F or less assuming loss of one train under
maximum heat load in the pool.
The pool is designed to handle 1312 spent
fuel assemblies. During fueling/defueling operations, the SF system pump
'B' is normally aligned to take a suction on the fuel transfer canal and
discharge to the spent fuel pool.
The suction of pump B is isolated from
the suction of pumps A and C at that time.
2. Description of Events
A. General
At approximately 9:20 a.m. on May 17, 1990, the licensee informed the
resident inspectors that the SFP
had overflowed resulting in the
contamination of various areas in the plant including the Unit 1 and
2 combined control room. The inspectors immediately went to Unit 1
and 2 control room to assess the problem and to determine the cause
and the extent of the spill. The cause of the spill was determined
to result from performing steps out of sequence in OP/1/A/1102/15,
Filling and Draining Fuel Transfer Canal dated 4/25/90, Enclosure
3.3, Draining of the Transfer Canal.
The out of sequence resulted in
shutting the isolation valves between the SFP and the transfer canal
with SF pump B still taking a suction from the transfer canal and
discharging into the SFP.
The shutting of the valves occurred at
about 8:25 a.m.
and with the pump flow rate of approximately 1000
gpm,
the SFP filled to an overflow condition.
At approximately
9:15 a.m.,
two NLO's in the kitchen area (a room located in the
control room)
noted water running down the wall.
They went to the
sixth floor (one level above the control room) and saw that the water
was coming from the spent fuel pool area. They immediately notified
the CRO. The
CRO directed the NLO to proceed to the SFP area and
open SF-1, transfer tube 1A isolation valve, and at that time the CRO
stopped the SF pumps. Securing pump B stopped the injection of water
into the SFP.
Another NLO was directed to the outside of the
building to determine if water was present outside the fuel receipt
area door. He and other available personnel placed plastic sheeting
and gravel over the
storm drain and rapidly obtained absorbent
devices which would prevent any leakage from the SFP building area
getting into the storm drains and subsequently off-site.
personnel were notified and immediate action was taken to rope off
affected areas and commence contamination control efforts.
areas were covered with absorbent rags, plastic sheeting was used to
cover panels, sampling of the chemical treatment ponds was started,
2
airborne sampling in various areas performed,
smears taken and
traffic control initiated. This action was effective in limiting the
spread.of the contamination. The areas that were affected were the
following:
(see figures 2 through 9)
-
Auxiliary Building -
sixth floor (Figure 2) -
Spent Fuel Pool,
Spent Fuel Pool Change Room, Unit 1 and 2 Purge Rooms, stairs to
the Hot Machine
Shop,
a portion of the Unit 2 Ventilation
Equipment Room.
-
Auxiliary Building -
fifth floor (Figure 3) -
the portion of the
TSC and the Control Room from about 20 feet east of the west
wall to the west wall.
This did not interfere with normal
operation of Unit 2 or Unit 1.
-
Auxiliary Building -
fourth floor -
(Figure 4) Unit 1 and 2 West
Penetration Rooms and about one half of the East Penetration
Rooms.
-
Auxiliary Building -
third floor (Ground Level -Figure 5) -
the
area below the East Penetration Room on Units 1 and 2 and the
hallway in Unit 1.
-
Auxiliary Building -
second floor (Figure 6) - Spent Fuel Pool
Heat Exchanger and Cooler areas and hallways adjacent to areas
directly beneath the East Penetration Rooms.
-
Auxiliary Building - first floor (Figure.7)
-
Low Pressure and
Building Spray Pump rooms Units 1 and 2 and Decay Heat Removal
Cooler rooms on Units 1 and 2.
-
Outside Auxiliary Building (Fuel
Receiving Bay)(Figure 5)
ground level between Unit 1 and 2 BWST about 870 square feet was
contaminated.
As a result of water entering the Unit 2 penetration rooms,
the
humidity exceeded 85 percent which resulted in both PRV systems being
declared inoperable. Although the TS does not specifically address
humidity requirements in the operational requirements for the PRV
system, the operators recognized that the systems would not perform
adequately if needed in the high humidity condition.
At this time,
this was a conservative action taken by the operators.
This .placed
the unit in a 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> LCO as required by TS 3.15. Subsequent review
by the Design Engineering staff confirmed that this action was
correct and that the PRV system should be declared inoperable in a
high humidity environment. Action was taken to reduce the humidity
level by cleaning up the water in the penetration room and placement
of portable fans and coolers. The humidity was reduced to less than
60 percent and the LCO was exited at 4:44 p.m.
3
A FRP
and a Materials inspector from Region II
were conducting
independent inspection activities on site at the time of this
occurrence. The resident inspector req.uested their assistance. They
reviewed the activities of the licensee following the spill (see
paragraphs 4 and 5.a). An electrical inspector was dispatched to the
site from Region II to review electrical areas that may have been
affected (see paragraph 5.b).
B. Chronology of Events
May 13 -
-
Commenced Refueling
May 16 -
12:10 p.m.
-
Reactor Building Purge System removed
from service for system maintenance
Late on 5/16 or
Reactor Building heated up slowly
early 5/17
causing slight buildup of pressure in
containment resulting in SFP level
increase
which
caused the
level
instrument to peg high and the lock in
of the high level alarm.
May 17 -
6:57 a.m.
-
Completed Refueling
7:00 a.m.
-
Commenced component verification of
reactor vessel
8:24 a.m.
-
Valves SF 1 & 2 closed and red tagged
in preparation
for
pump down of
transfer canal. Evolution performed out
of sequence.
Authorized by
shift
operations management.
-
9:00 a.m.
-
CRO notified that water was
accumulating in
room hatch area
(1st level) - NLO's were dispatched to
investigate
-
9:10 a.m.
-
Two NLO's in kitchen noticed water in
area of west wall and went to 6th floor
to investigate
-
9:10 a.m.
-
NLO's on 6th floor reported to CR that
SFP was overflowing
9:10 a.m.
-
SFP pumps A & B secured
0II
4
NOTE
This stopped the pumping of water from
the transfer canal into the SFP.
9:10 a.m.
-
SFP pump A restarted
9:10 a.m.
-
CRO instructed a NLO to open SF-i
(NLO required to don anti-contaminated
clothing and also clear tag)
9:11 a.m.
-
Unit 2 Supervisor instructed NLO to
check outside of fuel receiving bay for
water.
On
the
way
through
the
Auxiliary Building the NLO saw several
people including a HP individual,
and
told them what was happening and to
obtain additional
HP assistance.
continued into yard area.and with other
personnel in area covered storm drain
in vicinity and commenced covering
water with absorbent materials.
9:16 a.m.
-
Received computer alarm on Unit 2
indicating a high humidity in the
Penetration room
-
NLO dispatched to
investigate.
9:17 a.m.
-
Shift Supervisor notified in addition
to other plant management
9:20 a.m.
-
Plant Management Notified NRC resident
inspector notified
9:22 a.m.
-
Resident inspector notified FRP
inspec.tor
9:22 a.m.
-
NLO reported water standing in floor
of Unit 2 East Penetration room
Performance personnel dispatched to
obtain wet bulb humidity measurement
9:30 a.m.
-
Red tag cleared on SF-1, NLO dressed
out in anti contamination clothing and
opened SF-i approximately 3 turns
level decreased to slightly below the
top level in SFP as level equalized
with transfer canal
9:35 a.m.
-
By this time, radiation areas had been
identified
and
roped
off,
covered, plastic over panels in control
room, smear
sampling
and airborne
5
sampling in process,
- 3 CTP sampling
initiated,
and
supervisors in
various areas directing various site
personnel. in control/cleanup activities
10:00 a.m.
-
Resident Inspector notified Region II
10:39 a.m.
-
Results on sample from #3 CTP
indicated no boron detected into or out
of pond.
No
isotopes identified in
samples.
12:26 p.m.
-
Performance reported Unit 2
room
humidity
92%
Operations declared both
Room Ventilation (PRV)
systems out of
service and entered TS
LCO 3.15 based
on inoperability at 9:16 a.m. This is a
12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> LCO.
12:30 p.m.
-
Operations notified maintenance to
place spot coolers in penetration rooms
and obtained additional personnel to
assist in decontamination of these
areas.
3:55 p.m.
-
Performance notified Operations that
humidity in the Penetration rooms was
less than 60%
4:44 p.m.
-
PRV's declared operable and TS 3.15
LCO was exited.
3.
Radiological Review
A. Initial Notification and Radiation Protection Staff Response to the
Event
At approximately 9:00 a.m. on May 17, 1990, the licensee's RP control
points began receiving calls from Operations,
RP technicians and
other licensee employees that water was overflowing the Unit 1 and 2
Spent Fuel Pool and coming out of overheads in various locations
throughout the Unit 1 and 2 AB and control room.
As calls came in
the RP personnel were dispatched to investigate the problem. The RP
technicians determined that the water was contaminated and notified
RP management.
The
RP personnel,
with the aid of other plant
employees from various groups began securing flooded areas by setting
up
contamination
control
boundaries
to
prevent
personnel
contamination. The RP staff continued identification and isolation
of affected areas until the spill ended a little after 9:30 a.m.
6
When notified of the spill the FRP inspector proceeded to the health
physics control points in the AB to receive initial radiological
information concerning the event. Following the initial briefing, by
the radiation protection control point personnel, the inspector began
walking down the spill boundaries starting in the licensee's control
room continuing through the yard and AB locations.
During that
walkdown the inspector observed radiation protection
and
other
facility personnel working expeditiously to limit the spill and
prevent personnel contamination.
The inspector monitored the
licensee's activities and plans for decontamination throughout the
evening and determined that the licensee was in control of the
radioactive contamination areas resulting from the spill.
The
licensee had developed a recovery plan and was proceeding with
decontamination efforts.
The inspector continued to monitor the
licensee's decontamination progress through May 19, 1990.
B.
Scope of Radioactive Contamination Spill
1.
Inside Auxiliary Building
The licensee estimated that approximately 10,000 gallons of
water spilled from the SFP wall. at the 844 foot elevation.
About one half of this water was collected in the
Cask
Decontamination Pit.
The remainder of the water spilled onto
six elevations throughout Unit 1 and 2 AB. Some water spilled
into the licensee's Unit 1 and 2 Control Room (away from main
control panel)
and the Cable Spread Rooms below the Control
room. The licensee also had water spill outside the AB at two
points on the west side of the facility.
All water in the AB
was thought to have been initially drained and processed through
the liquid radwaste systems. The water spilled in the Unit 1
and 2 Control Room and Cable Spread Room (which was less than 5
gallons)
remained pooled in spots until wet
vacuumed
and
processed by the liquid radwaste systems.
The collection and
disposal of the contaminated liquid collected in the yard is
discussed in the following section.
The contamination areas
from the SFP spill and their associated contamination levels in
disintegrations
per
minute
per
100
square
centimeters
(dpm/100 cm2) are shown in Attachment C.
On May 25, the licensee reported to the resident inspectors that
activity had been identified in the sanitary waste pond.
This
pond does not receive discharges from any system that would
normally contain radioactive material.
The activity was
identified as the results of the normal weekly sample which had
been takenon May 22, 1990. This analysis is normally performed
by the Dukes Applied Science Center since the equipment at that
facility is more sensitive than the equipment used on site. The
previous sample that had been taken on May
15 indicated no
activity.
The May 22 sample identified the following:
7
Co 58
1.06 E-7 (microcuries/milliliter)
Cs 134
2.50 E-7
Cs 137
3.73 E-7
I 131
1.39 E-8
Ag 110
1.11 E-8
(metastable)
Ce 139
8.39 E-8
The licensee immediately commenced sample of the sanitary waste
pond on a daily basis. In addition, a sample was taken on CTP 3
which receives the discharge from the waste pond.
No activity
was identified in CTP 3. A liquid waste release was generated
and will be included in the semi-annual effluent report to the
NRC. The concentration of activity released via liquid pathway
was calculated to be 0.12 of the concentration listed in
10 CFR Part 20, Appendix B, Table 2. The sample taken on Friday
morning indicated no activity in the influent lines to the waste
pond and levels of approximately 1.0 E-7 microcuries per
milliliter of Co58,
Cs 134 and Cs 137 in the effluent.
This
daily sampling process will continue until
samples indicate
activity levels have decreased to less than minimum detectable
levels.
The licensee at first speculated that the activity was the
result of someone during the cleanup of the SFP pouring some of
the contaminated waste in a non-controlled sink.
Further
actions con.sisting of dye checking various drains in the areas
affected, to determine where system drains were routed,
identified that a shower drain in the clean area of the spent
fuel pool change room is routed to the sanitary waste pond. It
is probable that water entered the waste pond through this path.
An evaluation is being made to determine what action, if any,
will be taken.
2. Outside of Auxiliary Building
The licensee estimated that less than 50 gallons of water leaked
out of the AB onto the ground at two points on the west side of
the building.
A NLO sent to check the fuel receiving bay
arrived in time to prevent the flow of radioactive liquid into a
yard drain. When the NLO arrived the asphalt area from the roll
up door to the fuel receiving bay was dry.
The NLO could see
that if water were to leave the fuel receiving bay it would make
-its way across the pavement into a yard drain that drains into a
CTP. The operator obtained a plastic bag from a worker in the
area and sealed the yard drain with the plastic and used rags
brought to the area by another worker to soak up the water
before it
could get to the drain.
The effort was hampered
slightly by a rain shower, that commenced after the drain was
sealed.
A small amount of water also exited south of the fuel
receiving
bay at an exterior door, leading to a Spent
8
Fuel Pool stairway.
The water at that exit made its way onto
gravel next to the door.
The licensee covered that area with
plastic when the rain began. Smear surveys taken of the asphalt
area
had contamination
levels up to 500 dpm/100 cm2.
The
licensee was able to clean up both outside areas by 2:00 p.m.,
the day of the spill.
The licensee mopped up the asphalt and
scraped up all contaminated dirt and gravel for solid waste
disposal. The licensee performed followup contamination surveys
of the two areas after decontamination and initiated periodic
sampling of the yard drain discharge pipe at the CTP.
The
licensee also closed the pond spillway gate and took several
samples of the
CTP water for boron concentration and
radioisotopic analysis. All samples of the yard drain and CTP
did not detect any radionuclides and had less than 10 ppm boron.
The licensee did get a sample of the radioactive liquid spilled
outside the AB.
A review of the radioisotopic activities
measured in a SFP sample taken two days earlier and of the water
spilled outside on May 17, 1990, showed good agreement with the
earlier sample having radioactivity levels slightly higher for
1-131,
Co-58,
Cs-134 and Cs-137 isotopes.
The licensee
took air samples in the larger area outside and
no airborne
radioactivity was identified.
C.
Recovery and Decontamination Efforts
On Thursday afternoon May 17, 1990, the licensee began formulating a
plan for decontamination of areas contaminated during the spill.
The
licensee issued a decontamination priority list with the control room
area and a main corridor outside the Unit 1 and 2 change room on the
796 foot elevation at the top of the list. The licensee's scheduled
decontamination crew of 9 for the evening shift was doubled and split
into three 7 person crews with a HP technician assigned to each
group. A fourth decontamination crew of operations personnel
was
also assigned for duty that night.
At 2:00 p.m.
On
May
18,
1990,
the licensee had decontaminated,
surveyed
and
removed contamination boundaries for the following
areas:
Elevation
Location
771'
Unit 1 & 2 LPI Hatch Area
783'
Unit 1 Corridor
796'
All Outside Areas Were Cleared May 17, 1990
796'
Unit 1 Corridor
796'
Hot Machine Shop
796'
Hot Machine Shop Dressout Area
809'
Unit 2 Stairwell
809'
Unit 1 Stairwell
822'
Unit 1 & 2 Technical Support Center
9
822'
Unit 1 & 2 Control Room Cabinets
838'
Unit 1 & 2 Spent Fuel Pool Dressout Area
838'
Unit 1 & 2 Corridor
838'
Unit 1 & 2 Purge Fan Room
The contaminated areas that had the major effect on operation and
outage activities had been decontaminated and the licensee decided to
continue
throughout
the
weekend
with
the
normal
outage
decontamination support staff.
The licensee planned to increase
decontamination efforts again on Monday May 21, 1990.
When the inspection ended, the licensee had decontaminated all of the
areas that had been clean before the spill, with the exception of the
following:
Elevation
Location
771'
LPI Cooler Rooms 108 & 121 (50% complete)
783'
SFP Heat Exchanger/Pump Room 218
783'
Caustic Mix Area Room 208
796'
Cask Decontamination Room 348
796'
Pipe chases Room 306 and 327
809'
East and west Penetration Rooms
838'
Spent Fuel Pool Area
838'
Purge inlet Rooms
D. Evaluation of Licensee Radiation Protection Activities During the
Event
The licensee's response to the event was timely and effective. No
personnel contamination resulted during the event.
(Note: One
individual became contaminated the afternoon of the spill when a
posted contaminated area of the spill was entered incorrectly.)
Licensee personnel from all plant work groups worked well with each
other during the event to protect personnel and equipment.
The
licensee developed and implemented a workable recovery plan.
When
the contaminated liquid spilled into the yard, the licensee's staff
took sufficient steps to prevent the release of radioactivity from
the site to the environment and took sufficient measurements to
ensure no uncontrolled radioactive releases occurred.
4. Materials Review
A.
Mechanical Inspection
On May 17 and 18,
1990 following notification of the contaminated
water spillage and entry in the AB spaces, the inspector performed a
walkthrough inspection to observe and ascertain whether contaminated
water came into contact with metal fasteners, mechanical components
and/or piping.
The walkthrough inspection disclosed that pipe
location and configuration precluded these components from coming
10
into contact with
contaminated water,
except for Unit 2 East
Penetration Room
and Unit 1 Penetration
Room.
The latter was
inaccessible
because
contamination
was
in the
range
of
150,000 dpm/100cm2. In Unit 2 East Penetration Room,
contaminated
water entered through two areas. In one area, entry was made down
the Reactor Building wall and onto the floor.
In the other, entry
was through pipe penetrations in the ceiling. Water coming down from
these penetrations cascaded over piping located close to the ceiling
and down onto the floor. The inspector observed round, droplet like
residue of a white substance, thought to be crystals from borated
water. The condition was extensive in that it
was observed on all
the lagging on piping near the area of the spill.
Piping affected by
this spill was identified with the following systems,
component
cooling,
low and high pressure injection, containment purge,
feedwater, liquid waste drain and spent fuel line valve SF-96.
The
inspector expressed concern over the possibility that boric acid
crystals may have permeated through the insulation to the pipe
material, i.e, stainless steel weld joints, or carbon steel fasteners
which may be susceptible to corrosion.
Following discussions with
cognizant engineering personnel
and management, the. inspector
understood that following recovery of the contaminated areas,
steps
will be
taken to assess,
qualitatively and quantitatively, the
presence of boric acid on these components.
Corrective action(s)
will be determined following these assessments.
The inspectors will
followup on this concern on a future inspection.
B.
Electrical Inspection
1. Background
The electrical walkdown performed by the inspector concentrated
on floors 2 thru 5 since most of the electrical equipment of
concern was located on these floors. This included the Units 1
and 2 shared Control Room, Cable Spreading Rooms, East and West
Penetration Rooms, Pipe Chase Rooms (306 and 327), and Component
Cooling Water pump motors located in area 216. The inspection
consisted
of
examining
the
inside
of
electrical
and
instrumentation cabinets for signs of moisture intrusion on
wiring, terminal blocks, circuit boards,
etc.
Table 1 and 2
provide a list of both safety and non-safety electrical
equipment examined during the walkdown.
2.
Inspection Details
Approximately
70
safety related and
non-safety related
electrical panels in the Unit 1 and 2 Control Room were examined
and found to be acceptable with no visible signs that any
moisture had entered the cabinets. The Control Room is located
on the fifth floor of the AB which is one floor below the SFP.
11
The Unit 2 Cable
Room located below the Control
Room,
was
observed to have some contaminated water near the Transducer and
Switchyard Control Termination Cabinets. No visible signs of
water
or moisture were
found inside these cabinets.
The
corresponding Cable Room on Unit 1 was also inspected with no
contaminated water found.
Inspection of the other elevations
revealed that most of the electrical
equipment such as
penetrations, instrumentation, valve operators, and motors were
located above the floor grade with no visible signs of moisture
residue on the junction box covers. Conduit cable entrances were
not open at the top.
During the walkdown in the Unit 1 East and West Penetration
Rooms, the inspector noted that electrical penetration EC-10 had
a film on the junction box cover that may have been caused by
the spill.
This penetration was considered representative of
all penetrations in this area.
The
inspector requested a
licensee technician remove the cover for a visual inspection.
No signs of moisture were found in the box.
However, it was
noted that two wing bolts were missing from the cover. The
licensee's technician documented this deficiency on Work Request
51578J. The inspector found this to be acceptable.
C. Summary and Conclusions
A walkdown
inspection was performed
on both safety related and
non-safety related electrical equipment located in various areas and
elevations of the AB known to have been contaminated. The inspection
identified no significant damage to electrical equipment due to
moisture intrusion. Of the electrical equipment examined internally
no visible signs of moisture intrusion were identified.
5. Operational Review
Upon being informed of the spill, the CRO immediately recognized why the
was overflowing
and took prompt effective actions to stop the
overflow. Further discussion by the inspector with operations personnel
indicated that shift management
had decided that the Transfer Tube
Isolation Valves,
SF-1 and SF-2 were to be
shut.
This would allow
expeditious entry into the next evolution following reactor core component
verification which was to pump the water out of the transfer canal into
the BWST. It was not recognized at that time that the SF system B pump
was taking a suction from the transfer canal and discharging into the SFP.
Prior to beginning of this operating shift, the SFP level indication meter
had pegged high and the annunciator was actuated indicating a SFP high
level.
The SFP high level was caused by a slight increase in RB pressure
which had occurred over the previous
24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
At this point no
indication was available in the control room to alert the operators if an
increase in level occurred. The operator involved with refueling and the
CRO recommended that SF-1 and
SF-2
be left open until
component
verification was completed in case
an
error in fuel
loading was
12
identified. Shift management discussed the recommendation of CRO and
refueling operator and continued with the process to shut SF-1 and SF-2.
The procedure that was used for this evolution was OP/1/A/1102/15, Filling
and Draining of the Transfer Canal,
Enclosure 3.3, Draining the Transfer
Canal.
This procedure is written to first remove the SF system pump B
from operation,
and realign the associated valves and then shut and tag
SF-1 and SF-2. The *Unit 1 Supervisor (Senior Reactor Operator) authorized
steps in the procedure to be performed out of their written sequence.
This is a common practice and is allowed by their OMP.
OMP 1-9, Use of
Procedures, Section 6.3, allows operators, one of whom is a supervisor who
holds a senior operators license, to perform procedural
steps out of
sequence. This same section, however, also specifies that no deviation
from the original intent of the procedure is allowed without an approved
procedure change. The inspector review indicated that, for this case the
out of sequence was a change in the intent of the procedure and resulted
in a violation of OMP 1-9. TS 6.4.1 requires that the station be operated
in accordance with approved procedures. Based on this requirement, the
failure to operate in accordance with the requirements of OMP 1-9, Section
6.3 is identified as Violation 50-269,270,287/90-16-01:
Failure to Follow
Procedures Resulting in Overflow of Spent Fuel Pool.
6.
Exit Interview
The inspection scope and findings were summarized on May 23,
1990, with
those persons indicated in Attachment B.
The inspector described the
areas inspected and discussed in detail the inspection findings.
The
licensee did not identify as proprietary any of the material provided to
or reviewed by the inspectors during this inspection.
0II
13
ATTACHMENT A
List of Acronyms and Abbreviations
-
Auxiliary Building
BWST
-
Borated Water Storage Tank
CO
-
CRO
-
Control Room Operator
-
-
Chemical Treatment Pond
-
Engineered Safeguards
-
Facilities Radiation Protection
-
Health Physics
I
-
-
Integrated Control System
LCO
-
Limiting Conditions For Operation
-
Low Pressure Injection
-
Maximum Permissible Concentrations
-
Non-licensed Operator
OMP
-
Operations Manual Procedures
PRV
-
Penetration Room Ventilation System
-
Radiological Protection
-
SF
-
Spent Fuel Cooling System
-
Spent Fuel Pool
TS
-
Technical Specification
14
ATTACHMENT B
Persons Contacted
- B. Barron, Station Manager
T. Coutu, Unit 1 Operation Manager
S. Coy, Supervising Scientist
- T. Curtis, Compliance Manager
L. Davis, Nuclear Control Operator
R. Emory, Nuclear Plant Engineer
W. Henderson, Instrument & Electrical Technician
0. Jones, Instrument & Electrical Foreman
- J Long, General Supervisor Station Sciences
- B. Millsaps, Maintenance Engineering Manager
D. Repko, Associate Engineer
G. Rothenburger, Integrated Scheduling Superintendent
R. Slocum, Radiation Protection Supervisor
J. Snowden, Operations Shift Supervisor
S. Spear, General Supervisor Station Sciences
- D. Swiegart, Operations Superintendent
M. Thomas, General Supervisor Station Sciences
C. Witherspoon., Nuclear Assistant Shift Supervisor
Other licensee employees contacted included technicians,
operators,
0
mechanics, radiological controls personnel and management personnel.
NRC Resident Inspectors
- P. Skinner
B. esai
L. Wert
- Attended exit interview.
0D
15
ATTACHMENT C
Initial Contamination Areas
Floor Elevation
Location
Contamination
Level s(dpm/lO0cm2)
6th
838'
U-1,2 Walkway Around SFP
15,600
838'
U-1,2 Instrument Cage
6,100
838'
U-1,2 SFP Change Room
1,000-2,500
838'
Stairwell (HMS to SFP)
3,000-25,000
838'
U-2 Purge Equipment Room
13,000-32,000
838'
U-1 Purge Equipment Room
10,000-14,000
5th
822'
U-1,2 TSC (Lockers/Floor)
1 800
822'
U-1,2 CR Cabinet Area
1,090
4th
809'
West P/R
2,000-5,000
809'
East P/R
2,000-15,000
809'
U-2 Cable Room
1,290
809'
U-i West P/R Room 409
2,500-11,150ccpm**
809'
U-i East P/R Room 402
4,50Odpm-13,800ccpm**
3rd
796'
U-2 (RM327) Pipe Chase
10,000-59,000
796'
Hot Machine Shop
1,378
796'
Hot Machine Shop Dressout Area
1,300-50,000
796'
Fuel Receiving Bay
<1,000
796'
Yard Outside Cask Decon Tank
796'
Yard Outside Fuel Receiving Bay
1,400
796'
U-i (Rm306) Pipe Chase
11,900ccpm
796'
U-i Corridor @Freight Elevator 2,0O0dpm-4mRad*
796'
U-1 Cask Decon Tank Rm(Rm348)
12,000-18,000
2nd
783'
U-2 Corridor Outside Rm 217
1,100-1,800
Seal Supply Filter Rm.(Rm217)
783'
U-2 Corridor Outside Rm208
2,400
Seal Supply Filter Rm(Rm2O8)
1st
771'
U-2 LPI Cooler Room
7,800
771'
U-i LPI Hatch Area (Rmil9)
3,000-9700
771'
U-i LPI Cooler Room (RmlO8)
1,200-19,400
771'
U-i Corridor @Freight Elevator
- Ceiling tile that acted like a filter
"Multiply corrected counts per minute (ccpm) by 10 to obtain dpm
equivalUent.
NOTE
All
air
samples taken
during the
event
indicated airborne
radioactivity was less than 25 percent of maximum permissible
concentration (MPC) level
l
16
Table 1
Units 1 and 2 Control Room Cabinets Inspected
Reactor Protection System Channels (RPS)
RPS Channel No. D2
RPS Channel No. D1
RPS Channel No. C2
RPS Channel No. C1
RPS Channel No. B2
RPS Channel No. BI
RPS Channel No. A2
RPS Channel No. Al
RPS Channel No. E
Engineered Safeguards (ES) Logic Channels
ES Logic Channel No. 6/8
ES Logic Channel No. 2/4
ES Logic Channel No. 5/7
ES Logic Channel No. 1/3
Engineered Safeguards Analog Channels
ES Analog Channel No. A
ES Analog Channel No. B
ES Analog Channel No. C
Integrated Control System (ICS)
Cabinets No. 4 through 11
ICS ES Even Channel Normal Cabinet No. 9
ICS ES Odd Channel Normal Cabinet No. 8
ICS Cabinets No. 12 through 14
ICS Cabinets No. 1 through 3
Fire Protection Panels
Honeywell Fireprotection Panel
Fire/Smoke Detection and Alarm System [PYR-A-LARM] Panel
ICS Simulator Cabinets
ICS Simulator Cabinets No. 1 through 3
17
Table 2
Unit 2 Cable Room Cabinets Inspected
Transducer Termination Cabinets
Cabinet No. 2TDC1
Cabinet No. 2TDC2
Cabinet No. 2TDC3
Switchyard Control Termination Cabinets
Cabinet No. 2SCTC5
Cabinet No. 2SCTC6
Events Recorder Cabinets
2CCTV Cabinet Nos. 1 and 2
2SCTC Cabinet Nos. 5 and 6
Engineered Safeguards Cabinets
ES Odd Channel Relay Cabinet No. 2ESTC1
ES Even Channel Relay Cabinet No. 2ESTC2
---
7SPENT
FUEL POOL.
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50.0
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CC,1
0
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L
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,
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53I
3um
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)"
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.
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