IR 05000313/1978005
| ML19320A071 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 03/06/1978 |
| From: | Baird J, Brown G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML19320A065 | List: |
| References | |
| 50-313-78-05, 50-313-78-5, NUDOCS 8004140684 | |
| Download: ML19320A071 (5) | |
Text
.
_
_ _ _ _
. -.
_ _ _ _ _ - -.
_
.
.
.
.
-
O'
U. S. NUCLEAR REGULATORY COMMISSION 0FFICE OF INSPECTION AND ENFORCEMENT
REGION IV
REPORT OF INVESTIGATION IE Investigation Report No.
78-05 Docket No.
50-313 Subject: Arkansas Nuclear One, Unit No.1 Investigation based on a report that a reactor coolant line had broken resulting in spread of contamination throughout the reactor building and exposure of individuals requiring administration of chemicals internally to three individuals.
Period of Investigation:
February 13 and 14,1977 n
n
- ' '2 " M 3/4/7?
Investigator:
t~
/
J. B. B
- d
diation Specialist Date Approved by: h d.
/* W
[h
'
/
YTien TI. Brown, Ciief, Fuy Facility and
'
Date
%
Material Safety Branch
.
O 8 0 0 414 o 6 d
.-
_
...
-..
.
.
..
,
-2-REASON FOR INVESTIGATION
A telepi.one call was received from the Associated Press, Little Rock, Arkansas, on February 9,1978, inquiring about infonnation they received
,
from an informant that a coolant line had ruptured, resulting in contamina-tion of the plant and exposure of three individuals requiring internal chemical treatment.
SCOPE OF INVESTIGATION To determine the veracity of the infonnant's report, and if verified, to determine if personnel exposures exceeded regulatory requirements.
.
CONCLUSIONS O
The licensee discovered a leak in a Reactor Coolant Pump e.a) water sensing line on February 3,1978, during a shutdown for a planned refueling 131, was found to have been spread outage.
Contamination, including
throughout contaminment by the circulating fans. Numerous persons were contaminated externally and internally during work in containment.
Exposures and containment contamination did not exceed regulatory require-ments and was not reportable to NRC.
~
SUMMARY OF FACTS j
'
On February 9,1978, the Associated Press, Little Rock, Arkansas, contacted Region IV inquiring about information they received from an
'
informant that a coolant line had ruptured and the coolant had hit a fan resulting in exposure of three individuals requiring internal chemical treatment. The leak was further reported to have been in an instrument
.
line and all five floors of the plant were contaminated.
,
This investigation verified that the licensee had discovered a leak in a
,
Reactor Cooiant Pump Seal water. sensing line on February 3,1978, during
..!
shutdown for a planned refueling outage.
The primary coolant leak released radioactivity, including 1311, which apparently was picked up by the containment air circulating fans, resulting in spread of relatively high levels of contamination throughout containment.
The leakage was stopped by manual closure of an isolation valve.
!
_
-
..
_
.
_
_
, ____. _ _ __
.
.
.
.
,
.
-3-As a result of the initial inspection in containment, closure of the isolation valve and subsequent activities in the containment, several individuals were externally and internally contaminated.
Records of whole body counting show that 32 individuals had some intake of 131I The maximum internal contamination for any individual was about 5.4 her-cent of the recommended Maximum Permissible Body Burden (MPBB) for 1311, and about 4.1 percent of the MPBB for 60Co.
The personnel exposures and contamination levels in the controlled area of the containment did not exceed regulatory requirements and were not reportable to the NRC.
!
4 i
.
!
!
l
-
.
.
. -....
.
-
.
.. -. -..
.
.
.
l
.
.
\\
d-4-
'
l DETAILS 1.
General The Region IV office received a telephone call from the Associated Press, Little Rock, Arkansas, on February 9,1978, inquiring about information they received from an unidentified informant that a coolant line had ruptured at Arkansas Nuclear One, Unit No.1 (ANO-1)
sometine within the last 14 days and toxic fumes had been emitted.
The coolant had hit a fan resulting in exposure of three people to radioactive material such that they had to ue treated with chemicals internally. This leak was further reported to be in an instrument line and all five floors of the plant were contaminated.
l On February 10, 1978, information was received from ANO-1 that the only known leak was in a line from Reactor Coolant Pump "C" low pressure seal to a pressure transmitter.
The line had been found to
'
be leaking during an inspection in containment just prior to shutdown for a planned refueling outage.
The leak was described as "very s
i
,)
small" and no cases of excessive radioactivity exposures or J
ingestions was known.
In addition no chemicals or " antidotes" for
'
ingestion of radioactive material had been administered.
.
On February 13 and 14,1978, a RIV Radiation Specialist visited AN0-1 to investigate the status of plant operations during the two week period prior to February 9,1978.
The investigation consisted of an examination of selected records and interviews with ANO-1 personnel.
2.
Persons Contacted Arkansas Power and Light, Co. (AP&L)
.
J. W. Anderson, Plant Superintendent C. H. Halbert, Technical Support Engineer L. Alexander, QC Engineer B. T. Moon, Operations Shift Supervisor C.
P'. Zimmerman, Operator R. A. Capehart, Operator
.
G. E. Redman, Operator M. M. Nichols, Assistant Health Physics Supervisor
.
R. E. Fishencord, Health Physicist l
O
\\>
'
~-
.
-
- -
.
...
__
.
-
_ _ _
..
..
.
.
..
-5-
3.
Description of Coolant Leakage,
,
'
Licensee representatives stated that the only known coolant line leakage during the period in question occurred in the seal water pressure sensing line from Reactor Coolant Pump "C".
This leakage into containment, estimated to be about 0.3 to 0.4 gallons per minute (GPM),-was discovered on February 3,1978, during an inspection in containment.
The reactor at this time was in a hot
!
shutdown condition in preparation for a planned refueling outage.
i The leakage was found to be between two isolation valves and was stopped by manually operating the isolation valves.
Licensee representatives also stated that contamination was found
through most of the Reactor Building containment, necessitating a few days of decontamination.
No overexposures were experienced and
no medical care or administration of chemicals to workers was necessary.
!
4.
Records I
a.
AN0 Station Log-Operations The AN0 Station Log was reviewed for the period January 23, 1978
.
through February 9, 1978. The following entries were noted:
,
Date Shift / Time Item Plant Status 1/31 D
1720 hours0.0199 days <br />0.478 hours <br />0.00284 weeks <br />6.5446e-4 months <br /> Chemist checked 40% power reactor building (RB)
atmosphere 2/2 D
1606 hours0.0186 days <br />0.446 hours <br />0.00266 weeks <br />6.11083e-4 months <br /> Start RB purge Reducing Power
2/3 A
0035 hours4.050926e-4 days <br />0.00972 hours <br />5.787037e-5 weeks <br />1.33175e-5 months <br /> 2 men in RB for leak Hot Shutdown inspection 2/3 A
0120 hours0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br /> 2 men out of RB Hot Shutdown
,
2/3
1040 hour0.012 days <br />0.289 hours <br />0.00172 weeks <br />3.9572e-4 months <br />s-RCS cooldown Cooldown 2/3 B
1623 hours0.0188 days <br />0.451 hours <br />0.00268 weeks <br />6.175515e-4 months <br /> Reactor trip Cold Shutdown
-
i b.
Health Physics Log The ANO-1 Health Physics Log was reviewed for the period
. O January 23, 1978,- through February 9, 1978.
The ~ following s_ignificant entries were noted:
.
'
,
.
_,
_.
, _..
..
... ~..
. _.
.
,
_
.__,._._.-- _.,_.
.
.
b-6-
-
Date Item 2/2 Reactor Building (RB) air sample taken.
2/3 Numerous people contaminated when exited RB.
Hands and hair contaminated.
Smears from levels 424, 401 and Polar Crane taken.
All areas greater than 20,000 dpm/100cm2, 80% of areas greater than 100,000 dpm/100cm2 (removable contamination). All phones on levels 424 and 401 contaminated.
2/4 Decontamination on RB started.
Several people contaminated; all washed to background.
2/5 RB air samples taken.
c.
Air Sample Results Records of the results of various air samples taken before and after the initial entry into containment were reviewed as shown below. The air sample results show that airborne concen-trations of 131I were above the Maximum Permissible Concentra-A tion (MPC) of 9E-9 uCi/ml prior to the shutdown, and also the particulate airborne radioactivity was above the level of IE-9 uCi/ml, at which respiratory protection equipment is required by Health Physics procedures.
Record Date/ Time Nuclide Concentration (uCi/ml)
Purge Release 1/31 1720 hrs.
131I 1.1 E-8 Air Sample Log 2/2 2025 hrs.
Particulate 6.5 E-8 131I 9.7 E-8 Air Sample Log 2/2 2225 hrs.
Particulate 7.1 E-8 131I 1.0 E-7 Air Sample Log 2/3 0530 hrs.
Particulate 2.5 E-8 131I 5.3 E-11 Air Sample Log 2/3 0830 hrs.
Particulate 3.5 E-9 Air Sample Log 2/3 0917 hrs.
Particulate 3.7 E-9 Air Sample Log 2/3 2038 hrs.
Particulate 3.7 E-9 Health Physics Log 2/5 Particulate 1.0 E-9 Health Physics Log 2/6 Particulate 6.1 E-10
.
131I 2.3 E-10 l
,
e
.
_
-
-
.
..
_
-.
_.
.
.
s-
.
.
,
-7-
d.
Whole Body Counting Results The investigator reviewed the results of whole body counts for the period February 1 through February 8,1978.
The following tabulation shows the type and number of workers in which 131I was detected.
Results for 60 o are also included.
C
% MPBB Job Title No. Counted Dates Counted 131I 60Co
,
Laborer
2/6 0.4-1.1 0.7-1.4
'
Engineer
2/7 0.8 2.6 Electrician
2/3 2.6-4.t 0.5-3.4
.
Janitor
2/4 0.9-5.4 0.4-2.8 l
Mechanic
2/5 1.4 2.3 j
'
Operator
2/3 0.4 2.3
Health Physicist
2/4 - 2/8 0.5-3.2 0.6-4.1
'
Maintenance Repair
2/5 1.4 2.0 Assistant Professor
2/3 0.9 0.7 Technician
2/3 0.2-0.3 0.5.
5.
Interviews
The following infonnation was obtained from interviews:
a.
R. A. Capehart, Operator
-
Mr. Capehart stated that he entered containment with C. Zimerman on February 3, 1978, to inspect for leaks.
He stated that they noted water dripping like rain on the lower level of containment. He stated that he climbed a ladder to investigate the source of leakage and found the leakage spraying toward Reactor Coolant Pump "C" from a small line between two valves.
He obtained a valve number so that the line could be identified and the-leakage stopped.
He stated that during the inspection
l he had protective clothing on and was wearing 3M backpack'and hood respiratory protection equipment.
He further stated that
'
no contamination was found on his body when he exited contain-ment and he was not treated with any chemicals.
b.
C. P. Zimerman, Operator
-
i-
!
Mr. Zimerman stated that he entered containment with Mr. Capehart l
to make a leak inspection on February 3,1978. He stated that
!
he saw the water falling but did not spend much time in this
'
l f
l s
'
,
-
-..
, _ _ _,
_ _ _., _. _ _
..
...
. -..
.
.
, _. -..
_,_.
.
'
'
.
>V-8-area as he had to inspect the other side of containment. He stated no fans were operating except the containment cooling fans which operate during purge of the containment atmosphere.
He stated that he was wearing the same type of protective clothing and respiratory protection as Mr. Capehart, and no contamination was found on his body. He also stated that he was not treated with any chemicals.
c.
G. E. Redmon, Operator Mr. Redmon stated that he entered containment on February 3, 1978, subsequent to the leak identification, to isolate i
the line that was leaking by manually operating the isolation valves. He stated that he was able to complete this task in about three minutes of stay time.
He stated that his protective clothing was supplemented with a full plastic suit and double sets of gloves, and he was using a self-contained breathing l
apparatus (SCBA) type of respiratory protection device.
Mr. Redmon stated that contamination was found on his hand upon egress from containment and he was required to shower and wash his hand several times.
He stated that his hand was still contaminated after the washings and a chemical decontamina-tion agent (potassium permanganate) was used.
He further stated that a plastic bag was placed over his hand and he
" sweated out" the remaining contamination in in a short time.
He also stated that no chemicals were administered internally and no further restrictions were placed on his operations.
.
,