ML20207P208
| ML20207P208 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 01/06/1987 |
| From: | Cantrell F, Gloersen W, Holmesray P, Nejfelt G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20207P201 | List: |
| References | |
| 50-321-86-41, 50-366-86-41, IEB-84-03, IEB-84-3, IEIN-84-93, TAC-64455, TAC-64456, NUDOCS 8701150234 | |
| Download: ML20207P208 (16) | |
See also: IR 05000321/1986041
Text
7, - ..
UNITE 3 STATES
/pm RQg*o
NUCLEAR REGULATO3Y COMMISSION
'
["
nEGION li
.
,
g
- j
101 MARIETTA STREET, N.W.
t
ATLANTA, GEORGI A 30323
% m.* /
Report Nos.:
50-321/86-41 and 366/86-41
Licensee: Georgia Power Company
P. O. Box 4545
Atlanta, GA 30302
Docket Nos.:
50-321 and 50-366
License Nos.: DPR-57 and NPF-5
Inspection Conducted-
December 4-7, 1986
Inspectors:
(fh
/77-
/
b9
P. Holmes-Ray
Date Signed
~
f
2
/
/eq<~
l} &l8 -7
V. B. Glaersen
'"
~
'Datd Signed
7[
$(2.
ll5 8]
i f
>
G. M. Nejfelt
Da'te' Signed
Approved by:
.
T
/
D
Floyd S. Cantrell, dry,' Team Leader
Date Signed
~
Division of Reactor Projects
SUMMARY
Scope:
This special, announced augmented inspection was conducted to monitor
'the licensee's response during the release of radioactive water from the Plant
'
Hatch refueling floor into the environment discovered on December 3,1986.
The
areas inspected for this event included:
root cause determination, equipment
failure, the sequence of events, environmental impact, single mode failures
(e.g., risk of draining fuel pools and loss of secondary containment), and
licensee's knowledge of precursors (e.g., plant parameters, IE Bulletins and
,
Notices,etc.).
Results: Apparent violations were identified involving design and procedures.
The violations are being evaluated and will be forwarded under a separate cover.
8701150234 870108
PDit
ADOCK 05000321
0
- = _
.
.
.
.
-
.
REPORT DETAILS
1.
Persons Contacted
Licensee Employees
- J. T. Beckham, Jr. , Vice President, Pl. tnt Hatch
H. C. Nix, Pla1t Manager
- D. Read, Plant Support Manager
- R. D. Baker, N'aclear Licensing Manager, Hatch, Corporate
- H. L. Sumner, Operations Manager
B. McLeod, Maintenance Manager
T. R. Powers, L1gineering Manager
- R. W. Zavadoski, Health Physics (HP) and Chemistry Manager
- C. H. Coggin, General Support Manager
M. Geoge, Outages and Planning Manager
- 0. M. Fraser, Site Quality Assurance (QA) Manager (Acting)
- C. T. Moore, Training Manager
.
- C. C. Eckert, Nuclear Safety and Engineering Manager, Corporate
- S. C. Ewald, Radiological Safety Manager
- S. B. Tipps, Regulatory Compliance Superintendent
- G. A. Goode, Plant Engineering Superintendent
- S. B. Bethay, Regulatory Compliance Supervisor
M. Squires, Radiation Protection Foreman
M. Link, HP Supervisor
H. Davis, Consultant, GPC
D. Smith, HP Supervisor
Other licensee employees contacted included technicians, operators,
mechanics, security force members, and office personnel.
State Personnel
J. Hardiman, State of Georgia
NRC Personnel
- R. D. Walker, Director, Division of Reactor Projects (DRP)
- L. A. Reyes, Deputy Director, DRP
- F. S. Cantrell, Jr. , Section Chief, DRP
- P. Holmes-Ray, Senior Resident Inspector - Hatch
- W. B. Gloersen, Regional Radiation Specialist
- G. M. Nejfelt, Resident Inspector - Hatch
- Attended exit interview
-
.
.
.
.
'
2
.
2.
Exit Interview (.30703)
The inspection scope and findings were summarized on December 6, 1986, with
those persons indicated in paragraph 1 above. The inspectors 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.
The licensee acknowledged the findings and took no exception.
3.
Overview
a.
Description of Event
On December 2,1986, a Plant Equipment Operator (PEO), in the process
of restoring a clearance on air drop station valves, noticed an air
valve in a not fully shut position (mid position). Operations
Departnent letter, LR-0PS-002-0286 of February 3,1986, requires that
all in use hose station valves be tagged open on a clearance. The PE0
closed this partially open, not tagged, air valve. The valve closed by
the PE0 isolated the single air supply to the transfer canal's six
inflatable seals. The inflatable seals, not being entirely leak tight,
slowly deflated (over the period from air isolation on December 2, 1986,
at 10:00 p.m.,
until the pressure was restored on December 3,1986,
at 10:30 p.m.) creating a leak path from the refueling pool into the
gap between the two reactor buildings and from there to the environment
and to areas of Unit 1 & 2 reactor buildings, Unit 1 & 2 turbine
buildings, the centrol building, the hot machine shop and the nitrogen
storage area.
The fuel pool level dropped about 5.5 fect (141,000
gal .) below the normal level before the seals were re-inflated.
Re pressurization of the inflatable seals stopped the loss of water
from the fuel pool. (See paragraph - 4 for a more detailed time line.)
b.
Contributing Causes for the Event:
(1) Neither a Deviation Report or a maintenance work order was written
when the air regulator supplying air to the transfer canal seals
was found defective at an unknown date and a valve in the same
line was throttled to control air to the seals.
.
.,
,
.
"
3
-
(2) The air valve to the transfer canal seals was not tagged open on
a clearance in accordance with Operations letter LR-0PS-002-0286
dated February 3rd [ Sic],1986. This letter also implies that all
non-tagged hose station valves should be closed.
(3) The pressure to the transfer canal seals was not required to be
monitored on a regular basis even though the pressure to other
inflatable seals on the refueling floor was monitored.
(4) The design of the transfer canal seals lends itself to redundancy
of air supplies to the inner and outer seals. As built, only a
single air source supplied all six seals. This was the air source
which was isolated, initiating the event.
(5) The leak detection system designed to detect leakage past the
transfer canal seals was inoperable due to improper valve position
(i.e., the drain valve was open) but, due to its design, was
probably incapable of performing its alarm function upon loss of
all air pressure to the seals even with the drain valve closed.
(6) The design of the seal leak detection system was also subject to a
common mode failure of the single air supply to all seals. Due to
the design of the leak collectors, leakage will only be directed
to the leakage detection system if the seals in the gap between
the two buildings are leak tight. This seal is not leak tight as
shown by this event.
Sufficient water must accumulate in the
building gap above the inflated seal to reach the horizontal
drain from this area to the leakage collection system,
c.
Efforts to Control the Radiological Release:
Once the source of the leak was determined, the air pressure was
restored to the inflatable seals and the flow from the fuel pool was
stopped.
'
During the night of December 3 and the morning of December 4, 1986, the
licensee took positive and effective action to determine the extent of
and to limit the spread of contamination. .', series of water samples
were collected to determine which outfalls contained contaminated water
(See Paragri.ph 9). Additionally, a series of dikes (dams) were constructed
to minimize the spread of the contamination.
The licensee promptly
performed radiation surveys of the affected buildings and the outfall
area of the swamp to determine the extent of the release.
It was
estimated that 141,500 gallons of water were released from the Fuel
Pool.
The licensee estimated that the total volume of water was
partitioned in the following manner: (1) 17,500 gallons were processed
through the radwaste system; (2) 80,000 gallons were released to the
swamp; and (3) 44,000 gallons were between the reactor buildings.
The
maximum amount of radioactive material that could have been released
was approximately 0.373 curies (based on a volume of 124,000 gallons).
.
.
--
-
-
-
.-
--
.
.
.- .
\\-
.
.
4
.
During the afternoon of December 4,1986, direct radiation readir.g>
along the outfall which led to the swamp ranged from 1-2 mrem /hr.
Direct radiation readings along the shoreline of the swamp ranged from
150-250 uR/hr (normal readings were typically 8-10 uR/hr).
Water
sample results at the location identified as a potential pathway to
the river (location "B" figure 1) indicated no detectable activity. The
water from behind the dikes and at the entrance to the swamp pool was
pumped back to tanker trucks, filtered through demineralizers, and then
discharged through the plant radwaste system with all normal discharge
precautions in place.
The fuel pool to transfer canal gates were installed on December 4,
1986, and by December 5,1986, the air supplies were configured such
that the transfer canal gate seals were fed from both units such that
the inner seals were supplied from one unit and the outer seals were
supplied from the other unit, thus redundancy was achieved. Also by
December 6,1986, the transfer canal seals were pressurized from each
unit such that a single loss of air supply would not cause the seals to
deflate.
The organization, manning, controls and coordination of the recovery
effort was rapid and effective.
The Technical Support Center (TSC)
functioned well as the recovery center.
The manning of the recovery
center was adequate, with all needed disciplines represented.
The
personnel at the spill area in the swamp were well managed and
effective in containing the extent of the contamination within the site
boundaries and in minimizing the area of the swamp which was
contaminated.
4.
Sequence of Events:
The following detailed chronology of the event was obtained from licensee's
logs and interviews.
Approprimate
Date
Time (EST)
Comment
Unknown
Unknown
Transfer
canal
inflatable
seal
pressure
regulator failed.
Its
supply isolation valve was throttled
almost closed
to
control
seal
pressure.
10-10-86
4:44 p.m.
Transfer canal leak detection alarm
calibration, 57CP-CAL-094-2,
completed.
Drain valve that was
left open defeated or reduced the
ability to detect a leak.
12-02-86
10:00 p.m.
Plant
Equipment
Operator
(PEO)
closed the service air hose station
valve found cracked open, while
restoring unrelated clearances.
- _ .
-*
-
.
.
.
5
"
.
12-03-86
8:30 a.m.
Unit-1 fuel pool skimmer surge tank
low level alarm (222') received.
Operators added water to fuel pool
from condensate storage tank (CST).
No further action deemed necessary.
12-03-86
11:30 a.m.
Second Unit-1 fuel pool skimmer
surge tank low level alarm received.
Closed dump valve to main condenser
hotwell from fuel pool cooling (FPC)
system.
Water added from CST to
fuel pool.
12-03-86
2:00 p.m.
Leak discovered at Unit-2 reactor
building penetration, 2T43-H012A, on
112' elesation.
12-03-86
2:30 p.m.
Third Unit-1 fuel pool skimmer surge
tank low level alarm received.
system valve alignment was checked.
No discrepancies were identified.
Various FPC valves were closed in an
unsuccessful attempt to find the
leak.
The evening shift continued
search.
12-03-86
3:00 p.m.
Leak discovered at reactor building
penetration 112ft. elevation
12-03-86
4:15 p.m.
Water added to fuel pool to clear
low level alarm.
12-03-86
6:15 p.m.
Water added to fuel pool to clear
low level alarm.
12-03-86
8:00 p.m.
Water added to fuel pool to clear
low level alarm.
Leak location
determination continued.
12-03-86
9:37 p.m.
FPC pumps tripped on low, low fuel
pool surge tank level (215.8').
Water level was found by operator to
be
l'
below fuel pool
skimmer
suctions.
7
.
.
'
'
-
6
12-03-86
10:00 p.m.
Water
found
entering:
Unit-2
turbine building 112'
elevation;
Unit-1 and Unit-2 East cable ways on
130' elevation; and nitrogen storage
tank area. Water pressure prevented
opening door to nitrogen storage
tank room.
12-03-86
10:05 p.m.
Fuel Pool Water Level About 11s-2
Feet
Low.
While checking
air
pressure to all fuel pool inflatable
seals, air pressure on the transfer
canal inflatable seals was observed
to be 0 psig.
The closed air
isolation valve was opened and then
throttled to re-establish normal
seal pressure (25 +/- 5 psig).
LEAKAGE FROM FUEL POOLS STOPPED.
12-03-86
10:30 p.m.
Fuel pool level estimated to be 4'
below normal (222.3').
Note: Estimate was later revised to
be
5.5'
below normal
level
at
1:00 p.m.
on 12-04-86, based on
measuring
the
reference
level
observed.
Shift
Supervisor
forced
open
storage
tank
doors
revealing 2' to 3' of water.
The
water was released to the hot
machine shop area.
Also, water
was observed draining outside the
plant via the storm drain in the
nitrogen storage tank area.
12-03-86
10:45 p.m.
Manager of Plant Operations notified
and responded to site.
12-03-86
10:55 p.m.
Fuel pool level returned to normal
(226.3').
12-03-86
11:15 p.m.
Vice President of
Plant Hatch
arrived on site.
12-03-86
11:30 p.m.
Manager of Health
Physics and
Chemistry notified and responded to
site.
_ _ _ _ _
_ _ _ _ . _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - - _ - _ _
- _ _ _ _ _ _
-
.
7
.
12-03-86
12:00 p.m.
HP began taking samples and surveys.
Fuel
Pool
Cooling
and cleanup
returned to service,
12-04-86
1:28 a.m.
NRC notified of fuel pool transfer
canal seal leak by red phone.
12-04-84
2:00 a.m.
GPC emergency center in Atlanta, GA,
staffed including the President of
GPC.
12-04-86
4:00 a.m.
NRC provided additional information
by red phone.
12-04-86
4:30-6:30 a.m.
Telephone discussions to assess
significance by RII management and
resident inspectors.
12-04-86
7:00 a.m.
Meeting in NRC Region II Offices.
12-04-86
8:00 a.m.
Hatch resident inspectors dispatched
to site.
(From resident inspector
meeting in progress.)
GPC staffed site technical support
center (TSC) to coordinate recovery.
Region II made decision to send
augmented inspection team (AIT) to
,
site.
'12-04-84
9:00 a.m.
AIT departed Region II Offices.
12-04-86
10:00 a.m.
Started installation of transfer
canal
to fuel
pool
gates.
At
2:00 p.m. gates were in place and at
6:00 p.m. the gates were completely
installed with the seals inflated.
12-04-86
12:00 a.m.
Resident inspectors arrived at Plant
Hatch.
Initial inspection objectives
l
were communicated from Region II.
12-04-86
3:00 p.m.
AIT arrived on site.
Team briefed
,
by licensee management in TSC. Tour
"
conducted of outfall swamp and of
actions to contain radiologically
'
contaminated
water.
Extent
of
spread of contamination in swamp was
>
defined.
No radiological releases
directly entered the Altamaha River.
i
. , , -
-
_ _ _ _ _ _ _ _ _ _ ,
'
'
.
.
.
8
'
.
12-04-86
5:00 p.m.
Clean water
from plant drains
diverted from entering swamp to
reduce migration of contamination
and reduce volume of water to be
recovered
in
order to prevent
release to river.
12-05-86
8:00 a.m.
Licensee notified NRC of revised
calculation showing that approxi-
mately 141,000 gallons of water was
lost
from
fuel
pool.
Note:
previous estimate was approximately
50,000 gallons.
12-05-86
5:00 p.m.
After concerns were raised about
environmental damage to the swamp if
dikes were constructed and after
consultation with State and NRC
representatives, the decision was
made by the licensee not to dike the
swamp for containment purposes.
12-07-87
12:30 p.m.
AIT concludes site activities.
5.
Event Root Causes
Prior to December 2,
1986, the air regulator (100/20 psi) supplying the
inflatable seals on the seal assembly, which seals the gap between Unit-1
and Unit-2 reactor buildings, failed and the lever valve upstream of the
regulator was placed in a throttle position to compensate.
This throttle
position was almost shut. On December 2, 1986, at approximately 10:00 p.m.
(EST), this throttled valve was closed when a Plant Equipment Operator
(PEO), who was restoring clearances on the air system noticed that the valve
was almost shut, assumed it to be slightly out of position in the open
direction and placed the valve in the closed position. This action secured
the pressurization air to all six inflatable seals on the transfer canal
seal assembly.
At this time a slow depressurization of the seals commenced.
The root causes of the event were:
a.
Plant personnel did not adequately adhere to the requirement of 10 CFR 50
Appendix B,
Criterion V and Georgia Power Company's (GPC) accepted
QA Program (HNP-2 FSAR-17 Section 17.2.5) that requires that activities
affecting quality be prescribed by documented procedures of a type
appropriate to the circumstances and be accomplished in accordance with
these procedures as indicated by the following examples:
!
A Deficiency Report (OR) was not written as required by procedure
'
10AC-MGR-004, when a defective regulator was suspected and a valve
in the same line was throttled.
(Preparation of the maintenance
work order (MWO) would also have initiated corrective action.)
!
.
.
!
9
.
Corrective action is being tracked under a previous violation
(50-321,366/86-22-06) in that GPC's response to the violation
dated November 17, 1986, stated that corrective steps which will
be taken to prevent recurrence will be completed by December 26,
1986.
These steps included revising the procedure to make it
easier to understand, and completing training on the revised
procedure.
The valve in the air line with the regulator was throttled (at
some unknown time) without a procedure and was subsequently closed
on December 2,
1986, without an adequate procedure and without
knowing or determining the consequence. This open valve was not
tagged in accordance with Operation Letter LR-0PS-002-0286 dated
2/3/86.
This letter implies that untagged valves should be
closed.
The transfer canal seal leak detection system was calibrated on
10/10/86 using generic procedure 57CP-CAL-094-2, Robertshaw Level
Switch Calibration, even though this procedure did not provide
instruction for removal or return to service and could not be used
verbatim because of differences in the pipe and valve arrangement
to the leak detection system.
The Plant Equipment Operators', Daily Inside Rounds Procedure
34G0-0PS-030-1S did not require checking air pressure on the
transfer canal seals even though the procedure specified checking
the air pressure on the spent fuel pool gate's seals when a gate
is installed.
b.
Design measures were not established to ensure that the seals in the
transfer canal were capable of preventing a significant loss of water
from the fuel pool or to assure appropriate containment of any water
lost from the fuel pool as specified by criterion 61 of 10 CFR 50,
Appendix A.
The description of the transfer canal seal in the FSAR or
other plant documents did not adequately describe the trarsfer canal
seal or its safety function even though the transfer canal seals,
gates, fuel pool structure, and part of leak detection system are
classified as safety related.
c.
The seal arrangement in Figure 9.1-6 of the FSAR indicates an intent to
not rely on one set of seals; however, the failure to provide separate
air supplies defeated the redundant design upon loss of the single air
supply.
The failure to provide an alarm on loss of air to the seals
means that by design the alarm can only function af ter the seals fail
and due to the design of the leak collection system may not function
for a catastrophic seal failure,
d.
The spent fuel pool low level alarms were not documented in either the
control room operation logbook or the supervisor's logbook.
This
contributed to the delay in identifying that water was being added to
the spent fuel pool more than once per shift to compensate for leakage
and evaporation.
It was reported that two low level alarms were
recofved on the night shif t 12/3/86, and information was passed on at
. - -
- -
-
-
-
-
-
_ _ _ _ _ _ _ _ _ _ _
.
10
-
.
shift turnover. Three alarms were received on the day shift, but this
information was not passed on to the evening snift and may have not
been passed on to the supervisor. When the second alarm was received
on the evening shift additional effort was initiated to find leaks.
The on shift operating supervisor stated that he remembered a previous
spent fuel pool reactor cavity gate seal leak that caused the fuel pool
cooling pumps to trip on low surge tank level. Based on the previous
event, he headed for the refueling floor with a plant operator at
9:37 p.m.
At that time, he estimated the pool level to be about one
and one half to two feet low. They were checking gate seal air pressure
when they found no air pressure on the transfer canal seal.
Air
pressure was reestablished, the seals were reinflated and the leakage
was stopped about 10:00 p.m.
The pool level was estimated to be about
four feet low. The referenes guide was later measured and determined
to be about five and one half feet low.
Subsequent to this event, instructions have been issued to each shift
to document, in the control operator logbook, how much water is added
to the spent fuel pool and when.
6.
Cause of the Seal Leak Alarm Failure
On October 10, 1986, procedure 57CP-CAL-094-2, the safety related procedure
for calibration of the transfer canal leak detection level switch 2G41-N019,
<
was performed incorrectly.
Also the procedure is inadequate in that no
instructions for removal from service are included for this level switch.
To use this procedure in its current form for calibration of 2G41-N019 also
violates the principle of verbatim compliance with procedures since the
principle of verbatim compliance includes correcting procedures prior to use
if they do not work.
7.
The Potential Risk of Draining Both Fuel Pools
Based on calculation by the licensee, with the transfer canal gates out and
the transfer canal seal failed and no operator action, the water level would
drop to the bottom of the transfer canal which would leave 1.5 feet of water
over the active fuel.
If fill water were supplied to the pool thrnugh the
normal fill path at maximum flow rate using two pumps (1000 GPM), the pool
Invel would stabilize at approximately 7.75 feet above the active fuel. The
licensce's calculations also show that it took approximately 18 minutes for
the water level to drop 5.5 feet.
This is adequate time to move the
refueling bridge from the center of the transfer canal to either storage
pool and lower a fuel bundle into a storage location.
8.
Review of IEB 84-03, Refueling Cavity Water Seal and IEN 84-93, Potential
Loss of Water From the Refueling Cavity
Licensee's response to IEB 84-03 was by letter NED-84-500 dated
September 27, 1984. This response states in part, "The expansion joint has
redundant pneumatic seals on both Unit 1 and Unit 2 sides.
In addition,
there is another pneumatic seal in the expansion joint itself." This
-
________ ___________ __ _
_
,
_
.
.
'
11
.
response does not address the air supplies to the pneumatic seals nor that
if a single air supply were provided that the designed redundancy of seals
would be no longer functional. The response concludes, " Based on the above,
it is not considered credible to have a seal failure at Plant Hatch similar
to that which occurred at Haddam Neck." In response to NRC questioning, the
licensee reviewed this response and submitted a supplemental response on
December 23, 1986.
The Plant Hatch review of IEN 84-93 recognized the potential for seal
failure and water loss but stated that leakage alarms were installed for
detection of a leak and that procedures were in place to provide for water
restoration. This review by Plant Hatch concluded that no action need be
taken based on IEN 84-93.
Based on the events covered in this report, the licensee's evaluation of
both the IEB and the IEN were inadequate.
9.
Recovery and Cleanup Operations
The licensee's cleanup and recovery organization consisted of representa-
tives from plant management, maintenance, health physics and chemistry,
emergency planning, rumor control, and engineering. Although the Technical
Support Center (TSC) was not officially activated, the licensee utilized the
TSC for planning and directing the cleanup and recovery activities. The TSC
was manned for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> per day with two shifts. The inspectors noted that
the licensee's staff was well organized and utilized the various applicable
status boards as well as onsite and offsite maps for ease of information
flow.
The inspectors examined the cleanup activities in the swamp area located
near the cooling towers on the East side of the plant. Personnel working at
the cleanup site were receiving directions from the TSC. Controlled access
to the swamp area was established by health physics personnel to limit
spread of contamination to
previously established " clean" areas.
A
frisking station was established at the entry point.
In order to contain as much of the contaminated water leaving the storm
drain system as feasibly possible, the licensee built a series of earthen
dams along the creek bed which led into the swamp.
The water that was
contained in the ponds as a result of constructing the dams was pumped into
7000 gallon (approximately) capacity tanker trucks for subsequent disposal.
The licensee was planning to dispose of the water in the liquid radwaste
'
treatment system, provided that the treatment system could handle the
additional volume of water.
The contingency plan was as follows:
if the
contaminated water could not be treated by the liquid radwaste treatment
system, then the option would be:
(1) to take representative samples from
the tankers to determine curie concentration (typical concentrations were
approximately 140 9C1/7000 gallons) and (2) to release the content of the
i
-
-
.
.
-
-
-
- .
-
-
_ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ - - _ _ _ _ _ _ _ _ _ _ _
_ _ _ _ _ - _
__,
.
.
.
12
.
tanker into the plant's discharge canal, obtaining additional samples at the
beginning, midway, and end of the release. This release would be regarded
as a batch release with the creation of required discharge permits.
The
licensee was aware that the conditions and Action Statement of Technical Specification 3.15.1.3 would apply.
Additionally, the licensee had established several sampling stations along
the release stream, swamp area, and at an area (Sample "B") where seepage
from the swamp into the river was noted (See Figure 1).
Sampling stations
were also established at two other outfall pipes to ensure that the water
flowing out was not contaminated.
It should be noted that no detectable
activity was measured, as of December 6,1986, at sample location "B".
The
licensee's sampling program involved the collection of one liter water
samples at each sample location once per hour. The inspectors accompanied
licensee representatives and a state representative and observed the
collection of seven water samples. The samples were analyzed in the Plant
Hatch counting laboratory using a one liter Marinelli beaker geometry, which
was normally used for liquid radwaste analysis.
Four liquid samples were
split between the NRC, State of Georgia, and the licensee at sample
locations 3, 4, A and B.
The comparison between the licensee and NRC can be
seen on Table 1.
The data indicate that all licensee measurements were higher than the NRC
measured values.
This difference could be partially explained by the
relatively shorter counting times used by the licensee (600 seconds vs. 5000
seconds used by NRC/RII) and the resulting higher uncertainties associated
with the licensee's measurements. Additionally, it would have been more
appropriate to count these relatively low level samples in a low background
environmental counting laboratory. However, for qualitative analyses the
licensee's methods appeared to be appropriate to accomplish the task at
hand. It should be noted, that it may not be appropriate to use these data
quantitatively where accurate measurements would be needed to perform, for
example, dose calculations.
The licensee's corporate environmental affairs staff was involved with the
on going sampling program and estabitshing an augmented environmental
monitoring program to identify any significant migration of radioactive
material in excess of permissible levels.
The plans established by the
corporate environmental affaire personnel for an augmented sampling program
included taking over the swamp water sampling efforts from Plant Hatch;
obtaining sediment samples to characterize the swamp sediment; increasing
the frequency of surface water, vegetation, and sediment samples offsite;
and adding a composite sampler downstream of the swamp outfall.
The
frequency of the swamp water sampling was going to be reduced from the
present hourly rate to weekly sanples. Details of the augmented sampling
program were still being formulated at the time of this inspection.
The
licensee stated that the augmented environmental sampling program would be
implemented by December 15, 1986.
_
_ _ _ _
.
.
13
-
In plant cleanup activities were ongoing, while the swamp sampling and
cleanup were progressing. In plant cleanup activities were directed in the
following four main areas:
(a). nitrogen storage tank area;
(b). hot
machine shop;
(c). asphalt area outside the hot machine shop; and (d).
portions of the East cable way at the 130' elevation of the Unit-1 and Unit-2
reactor buildings. A temporary roof was put on the nitrogen storage tank
building until the contaminated portions of the asphalt area outside the hot
machine shop area were temporarily covered with Herculite (trademark) until
the surface can be removed and repaved. The licensee plans to replace the
damaged cable tray insulation on the East cable ways and to initiate
extensive cleanup activities in the hot machine shop.
Additionally,
engineering personnel were performing an evaluation to determine the amount
of water contained along the walls of the Unit-1 and Unit-2 reactors
buildings, turbine buildings, control building, and radwaste buildings. The
engineering staff was determining how to remove the water from between the
buildings so that it could be processed through the radwaste treatment
system.
10. Operators' Response to the Event
The operators response to the event once the spill had occurred was
commendable. The operators alertness to changing fill rates of the fuel
pool was lacking.
Had each refill of the fuel pool been logged in either
the Plant Operator's log or the Shift Supervisors log the increased
frequency might have been noticed and corrective action taken prior to
complete depressurization of the seals.
11.
Plant Response
Unit I was at full power and Unit 2 was in cold shutdown following refueling
when the spill occurred. No transient took place effecting plant operating
parameters.
-
-
-
-
-
-
4
6
,_ _
.e
- r
- .
.
_.0N
-
' ' "
4
_..,ooo
__
- wo -
-
t
..
W
...x__._
_1-
.--
l' N
-
--
-- =._.- . - _ _ . u, -
.
O
y
llh
Cri)-
O
'
'
'
.ir.
O
-'"'
- , '
,,',w
.
--N
'
][
/
'
<
,
..
,
Q.
Ag.
&n,,,, )
.. ..... ~ \\
r
.
pf s w
y
.
_
.
._
1
.
.
....
,.
l
l
i
r
[
a
i
j
~ l
==sa-
_
"'--
'
..d+g.
.
(
-L-
-
i
u
tw
.
,
--
-
,
.
,
-
,
,
-
=:
m..
.ia .
g
.
_.
N
!
' ,)
.
..
[Lr..____.
5
~-
<
qx
i
.
.
__ .
. . . . 3
3,,
1
. , -
.
y
-
.I
...
.
.
.
.
i
.:
-
e
/
-
L
O
.
,.
=
~
,
j
- " 9
JR
"J
3
'
/
\\g_
,g
.
s
a
w=,
+
. . . . . .
.-
'a.n
L
s
,
w& *
,
.
-
-
- &
N
\\\\
, ' .
V
f
f 3 *'l
,,,
,
J
~'
,
f!! b
k), -i
,,
.
C
.
l
.
~.
Figure-1
FT..
,
.
TABLE 1
,
.
Swamp Sample Results of Gamma Spectroscopy
Measurements at Plant Hatch, December 6s 1986
i Sample Location
i
Nuclide
l
Concentration (uCi/ml)
l
l(Licensee geometry = l
l
Licensee *
[
NRC**
1
I one liter marinelli)l
1 (Value i one sigma)
(Value
one sigma
I
I
i
l
I
I
- 3
I
Cs-134
l
1.22
0.21 E-6
I
8.57
0.28 E-7
I
I
I
1
1.34 1 0.20 E-6
[
1.30 t 0.03 E-6
[
I
I
I
I
I
>
I
- 4
i
Cs-134
I
7.96
1.58 E-7 l
2.83 1 0.17 E-7
I
I
I
I
7.53 1 1.48 E-7
1
4.42 1 0.19 E-7
[_
l
I
I
I
I
I
A
I
Cs-134
1
6.50 1 1.54 E-7
[
4.68 1 0.23 E-7
I
I
l
l
9.56 1 1.63 E-7
1
6.50 1 0.26 E-7
I
I
I
I
I
I
I
B
I
I No nuclides detected [ No nuclides detectedl
l
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
i
1
l
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
i
1.
I
I
I
I
I
I
I
.I
.
.
i
- All-licensee analyses were performed at Plant Hatch, each measurements was
based on a counting time of 600 seconds.
- All NRC analyses were performed in the Region II counting laboratory, each
measurement was based on a counting time of 5000 seconds,
s
.
e