[Federal Register Volume 63, Number 90 (Monday, May 11, 1998)]
[Notices]
[Pages 25880-25883]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-12390]
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NUCLEAR REGULATORY COMMISSION
Report to Congress on Abnormal Occurrences Fiscal Year 1997
Dissemination of Information
Section 208 of the Energy Reorganization Act of 1974 (Pub. L. 93-
438) identifies an abnormal occurrence (AO) as an unscheduled incident
or event that the Nuclear Regulatory Commission (NRC) determines to be
significant from the standpoint of public health or safety. The Federal
Reports Elimination and Sunset Act of 1995 (Pub. L. 104-66) requires
that AOs be reported to Congress on an annual basis. During fiscal-year
1997, six events that occurred at facilities licensed or otherwise
regulated by the NRC and the Agreement States were determined to be
AOs. These events are discussed below. As required by Section 208, the
discussion for each event includes the date and place, the nature and
probable consequences, the cause or causes, and the action taken to
prevent recurrence. Each event is also being described in NUREG-0090,
Vol. 20, ``Report to Congress on Abnormal Occurrences, Fiscal Year
1997.'' This report will be available at NRC's Public Document Room,
2120 L Street N.W. (Lower Level), Washington, D.C., about three weeks
after the publication date of this Federal Register Notice.
97-1 Loss of Two of Three High Pressure Injection Pumps at Oconee
Nuclear Station Unit 3
One of the AO reporting criteria notes that a major deficiency in
design, construction, control, or operation having significant safety
implications requiring immediate remedial action can be considered an
AO.
Date and Place--May 3, 1997; Oconee Unit 3, a pressurized water
nuclear reactor plant designed by Babcock and Wilcox Company, operated
by the Duke Energy Corporation (formerly known as Duke Power Company),
and located about 8 miles north of Clemson, South Carolina.
Nature and Probable Consequences--On May 3, 1997, the Oconee Unit 3
reactor was shut down and the reactor coolant system (RCS) was being
cooled down for inspection of the high pressure injection (HPI)
discharge piping. The need for the inspection resulted from RCS leakage
from a weld crack in the HPI makeup piping on Unit 2. Reactor pressure
was approximately 270 psig, RCS temperature was approximately 205 deg.
F, one reactor coolant pump (RCP) was running, and the Low Pressure
Injection System was being used to cool down the RCS. Makeup water to
the RCS to compensate for the temperature decrease was being supplied
from the letdown storage tank (LDST) by one of the three HPI pumps.
Makeup to the LDST consisted of periodic batch additions as needed.
These plant conditions were below the point where the technical
specifications required that the HPI system must be operable; that is,
required to mitigate a small-break loss-of-coolant accident.
Plant cool-down evolutions appeared to be normal until the ``B''
HPI pump started to cavitate and makeup flow to the reactor coolant
system was lost. A RCP seal water (which is also supplied by the HPI
pump) low-flow signal automatically started the ``A'' HPI pump.
However, it also began to cavitate. (The third HPI pump is not designed
to automatically start on this signal and remained in the standby
condition.) The operators stopped both pumps and began troubleshooting
the problem. A Notification of Unusual Event was declared when it was
recognized that the pumps would be inoperable past the shift that was
on duty. Unit 3 pressure and temperature were stabilized and there was
no immediate concern that conditions would worsen.
Later investigations revealed that the potential for a more serious
situation existed if there had been a small break loss-of-coolant
accident, which is the design basis for the HPI system, prior to this
event. If such an accident had occurred, all three of the HPI pumps
would have automatically started and become inoperable very quickly. In
addition, the pumps may have become air bound and unavailable when the
pump suction was transferred to the Borated Water Storage Tank to
inject into the RCS. This would have significantly complicated recovery
from the accident, but would have been within the Emergency Operating
Procedure guidance and training provided to the operators. It would,
however, increase the probability of core damage. The length of time
that Unit 3 was in this degraded status could not be accurately
determined, but the condition may have existed since start-up in March
1997, when plant conditions required that the HPI system be operable.
Cause or Causes--Loss of the HPI pumps occurred when all of the
water was inadvertently pumped from the LDST because of faulty level
indication. The erroneous level indication was caused by the loss of
approximately one-half of the water in the level detector reference leg
because of a slight leak in the instrument fitting. This loss of the
reference leg water caused the tank level instrument to indicate a
water level higher than the actual level, a condition that may have
existed since February 1997, the last time the reference leg was
verified to be full. It also caused the loss of the low-level alarm. As
a result of these conditions, the operators did not provide makeup
water to the tank when it was needed, resulting in the HPI pump
continuing to run until the tank was empty. The LDST level detection
system consists of two level instruments connected to a common
reference leg. Thus, the condition affected both level detectors
equally.
In addition, the control room operators did not properly monitor
and detect the inaccurate LDST level indications. They did not notice
that for a short period of time the indicated level stopped decreasing
and continuously showed the tank to be approximately half-full at the
same time water was being pumped from the tank.
Actions Taken to Prevent Recurrence
Licensee--Corrective actions included (1) the addition of a second
reference leg to the LDST to provide separate level indications, (2)
enhanced operator training and procedures, and (3) the performance of
an HPI System Reliability Study that is to be completed by December 31,
1997.
[[Page 25881]]
NRC--Escalated enforcement, which incorporated this issue, resulted
in the determination that a Severity Level II violation existed, and
the licensee was assessed a $330,000 civil penalty. Information Notice
97-38, ``Level-Sensing System Initiates Common-Mode Failure of High-
Pressure-Injection Pumps,'' was issued on June 24, 1997, to alert other
licensees to this event.
This event is closed for the purpose of this report.
* * * * *
Other NRC Licensees--(Industrial Radiographers, Medical
Institutions, Industrial Users, etc.)
97-2 Overexposure of a Worker at Mallinckrodt, Inc., in Maryland
Heights, Missouri
One of the AO criteria notes that any unintended radiation exposure
to an adult (any individual 18 years of age or older) resulting in an
annual shallow-dose equivalent to the skin or extremities of 2500 mSv
(250 rem) or more will be considered for reporting as an AO.
Date and Place--May 14-15, 1997; Mallinckrodt, Inc.; Maryland
Heights, Missouri.
Nature and Probable Consequences--On May 14, 1997, an employee was
removing radioactive waste from the hot cell where rhenium-186 (Re-186)
was used. The employee was performing this task manually, using gloves,
instead of remotely. When he left the area, he attempted to perform a
personal contamination survey but the survey meter immediately went off
the scale. He assumed that the high count rate was due to background
radiation from an adjacent radioactive material transport cart and,
subsequently, forgot to resurvey himself in a low background area
before he left the facility that evening. Upon arrival at work the next
day, he was told that his urine sample, which he had submitted before
going home the previous night, indicated iodine-131 (I-131) radiation
contamination and that he was restricted from working with radioactive
material. At that time, he performed a personal contamination survey
and detected significant levels of contamination on his left thumb
which subsequently was identified as Re-186. The I-131 contamination
level did not exceed the AO criteria for exposure to radiation from
licensed material.
The licensee estimates that the individual received a shallow-dose
equivalent of 6090 millisievert (609 rem) to an area of about 0.75
square centimeters (0.12 square inches) on the palm side of the thumb
of his left hand. Lower levels of contamination were found on the back
of his right hand and fingers. On May 15, 1997, the employee had
undergone decontamination to the extent that only approximately 4
percent of the activity remained.
The licensee surveyed the offsite locations where the employee had
been after leaving work on May 14, 1997. Low levels of Re-186
contamination were found on three locations inside the employee's
vehicle and on various items in the bathroom and kitchen of his home.
The employee's vehicle and home were decontaminated. The employee was
examined by a physician who identified no immediate health effects.
However, according to a report from an NRC consultant, a small
possibility exists for skin cancer to develop in the exposed area of
the thumb.
Cause or Causes--The cause of the event was a procedural deficiency
in handling waste from the Re-186 hot cell. Normally, radioactive waste
in other hot cells at the facility was handled with remote tools.
However, in this case, procedural controls did not require remote
handling of the waste. Once the employee completed the work, poor
radiation work practices were exhibited as he cross-contaminated his
hands when he removed his gloves. In addition, the worker did not
investigate the detection of high count rates during his first attempt
to perform a contamination survey.
Actions Taken to Prevent Recurrence
Licensee--The staff was instructed on the importance of conducting
proper personal contamination surveys and the proper use of protective
clothing. The use of Re-186 was suspended until improvements to
existing waste disposal procedures could be evaluated and implemented.
Plans were made (1) to compile all existing contamination protection
procedures into one contamination protection procedure, (2) to evaluate
the use of a portal type monitoring system, and (3) to post personal-
monitoring reminder signs at all laboratory exits.
NRC--NRC conducted a special safety inspection, proposed a $55,000
civil penalty on December 17, 1997, and the licensee paid the civil
penalty on January 20, 1998.
This event is closed for the purpose of this report.
* * * * *
Agreement State Licensees
AS 97-1 Multiple Transuranic Overexposures to a Worker at Isotope
Products Laboratories in Burbank, California
One of the AO criteria notes that any unintended radiation exposure
to an adult (any individual 18 years of age or older) resulting in an
annual total effective dose equivalent (TEDE) of 250 millisievert (mSv)
(25 rem) or more; or an annual sum of the deep dose equivalent (DDE)
(external dose) and committed dose equivalent (CDE) (intake of
radioactive material) to any individual organ or tissue other than the
lens of the eye, bone marrow, and the gonads of 2500 mSv (250 rem) or
more will be considered for reporting as an AO. In addition, another AO
criterion states that a serious deficiency in management or procedural
controls in major areas will be considered for reporting as an AO.
Date and Place--Between January 1 and December 31, 1995; Isotope
Products Laboratories; Burbank, California.
Nature and Probable Consequences--A radiochemist was assigned to
make transuranic and other types of sources. The transuranics utilized
included the isotopes of plutonium-238 (Pu-238), Pu-239, Pu-240,
americium-241 (Am-241), and curium-244 (Cm-244). During January 1995,
while making a Cm-244 source, it was discovered that the exhaust fan of
the fume hood where the source was being fabricated was not working. An
analysis of room air samples confirmed the loss of Cm-244 into the
working area.
Bioassay results disclosed that the fecal and urine samples
provided by the radiochemist contained Cm-244 and Am-241. The licensee
hired dosimetry and radiation protection consultants as directed by the
State Agency. Careful analysis of the bioassay data by these
consultants, which included dose summation and retrospective time
correction for various intakes, suggested that during 1995 the
radiochemist received a TEDE of 383.20 mSv (38.32 rem) and a CDE of
6900 mSv (690 rem) to the bone surfaces. The specific exposures were as
follows: (1) committed effective dose equivalent (CEDE) of 271.8 mSv
(27.18 rem) from Cm-244, (2) CEDE of 80 mSv (8 rem) from Am-241, (3)
CEDE of 4.4 mSv (0.44 rem) from Pu-238, Pu-239, and Pu-240, and (4) DDE
of 27.0 mSv (2.70 rem) from external radiation.
The State Agency discovered this incident during a routine
inspection on December 5, 1995, and was initially reported to NRC in
January 1996. During
[[Page 25882]]
a follow-up inspection, the State Agency learned that another Cm-244
incident took place and was significant. The State Agency also learned
of other exposure incidents that indicated the licensee had a deficient
contamination control program, an inability to conduct internal dose
assessments, and inadequate management oversight. The State provided
additional information on these events to NRC in 1997.
Cause or Causes--The licensee's radiation protection program was
inadequate and lacked important elements needed to ensure the radiation
safety of its workers. Some of these inadequacies were the lack of (1)
work permits, (2) glove boxes for certain types of work, and (3)
radiation procedural controls.
Actions Taken To Prevent Recurrence
Licensee--After the licensee's consultants conducted their review
and comprehensive audit of the existing radiation protection program,
they made recommendations to ensure future compliance with the license
and regulations. The licensee hired a competent radiation safety
officer, and the radiochemist was assigned duties that did not involve
the handling or processing of radioactive materials.
State Agency--The State Agency completed its investigation and is
committed to closely tracking the licensee's radiation protection
program to ensure continued compliance.
This event is closed for the purpose of this report.
* * * * *
AS 97-2 Overexposure of a Radiographer and an Untrained Technician at
Wolf Creek Mine in Walker County, Alabama
One of the AO criteria notes that any unintended radiation exposure
to an adult (any individual 18 years of age or older) resulting in an
annual total effective dose equivalent (TEDE) of 250 millisievert (mSv)
(25 rem) or more; or an annual sum of the deep dose equivalent (DDE)
(external dose) and committed dose equivalent (CDE) (intake of
radioactive material) to any individual organ or tissue other than the
lens of the eye, bone marrow, and the gonads of 2500 mSv (250 rem) or
more will be considered for reporting as an AO. In addition, another AO
criterion states that a serious deficiency in management or procedural
controls in major areas will be considered for reporting as an AO.
Date and Place--July 1, 1996; Wolf Creek Mine, Walker County,
Alabama.
Nature and Probable Consequences--A radiographer, employed by
Certified Testing and Inspection of Cottondale, Alabama, and a
technician, employed by Ultron, Inc., of Mt. Vernon, Illinois, were
performing industrial radiography at the Wolf Creek Mine in Walker
County, Alabama, when they became so distracted by problems with
excessively exposed film that they forgot they had an exposure in
progress and entered the high radiation area without making a survey
and changed the film with the source in the unshielded exposed
position. The radiographer had received prior radiation safety
training, however, the technician, an employee of Ultron, Inc., had not
received prior radiation safety training. The radiography film and the
device used to support the source and the film during exposures were
being supplied to the radiographer by Ultron, Inc.
Consequently, both individuals received unintended radiation
exposure. The State Agency estimated that the radiographer received a
dose of 530 millisievert (mSv) (53 rem) to his head and 48 mSv (4.8
rem) to the center of his body and the Ultron, Inc., technician
received a dose of 110 mSv (11 rem) to his head and 28 mSv (2.8 rem) to
the center of his body. Neither individual reported any acute radiation
symptoms.
The radiography film supplied by Ultron, Inc., had faster and
different exposure characteristics than the film usually used by
Certified Testing and thus was being overexposed during processing in
the darkroom. The darkroom, which was supplied by Certified Testing,
utilized a homemade ``safe light,'' which had been made a safe light by
the application of red spray paint. The radiographer did not realize
beforehand that the light would not be ``safe'' for the film supplied
by Ultron, Inc.
Cause or Causes--The radiographer entered a designated high
radiation area with his alarm ratemeter turned off and without
following his normal practice of cranking in the source and surveying
the guide tube and camera. The radiographer interpreted the silence
from the alarm ratemeter as an indication of safe conditions.
Unfortunately, when turned off, the alarm ratemeter gives the same
indication as it does when indicating safe conditions. In addition, the
radiographer did not utilize a collimator to reduce the exposure to
himself and the Ultron, Inc., technician.
Actions Taken To Prevent Recurrence
Licensee--The licensee stated that the radiographer did not develop
any symptom of acute radiation exposure and that its personnel were
reinstructed in the importance of performing surveys and using a
collimator. The licensee committed to the State Agency to verify the
training of all technicians, including those of the company that hires
the licensee to perform radiography.
State Agency--The State Agency cited the Licensee for the following
four violations: (1) excessive exposure to a radiation worker, (2)
excessive exposure to a member of the public (the Ultron, Inc.,
technician representative), (3) failure to prevent unauthorized entry
into the High Radiation Area, and (4) failure to exercise ALARA by
using a collimator. A civil penalty was considered but not imposed. The
State Agency recommended that both individuals contact the State and
seek medical attention if any symptoms of acute exposure should appear.
This event is closed for the purpose of this report.
* * * * *
AS 97-3 Radiopharmaceutical Misadministration at Mad River Community
Hospital in Arcata, California
One of the AO criteria states that a medical misadministration that
results in a dose that is equal to or greater than 10 gray (Gy) (1000
rad) to any organ (other than a major portion of the bone marrow, to
the lens of the eye, or to the gonads) and represents a dose or dosage
that is at least 50 percent greater than that prescribed in a written
directive will be considered for reporting as an AO.
Date and Place--February 28, 1996; Mad River Community Hospital;
Arcata, California. The State initially reported this event to NRC in
December 1996.
Nature and Probable Consequences--A patient was prescribed a dosage
of 3.7 megabecquerel (MBq) (0.1 millicurie [mCi]) of iodine-131 (I-131)
for a thyroid scan and uptake procedure. However, the patient was
administered a dosage of 262.7 MBq (7.1 mCi) of I-131. As a result, the
patient's thyroid received a dose of about 9100 centigray (cGy) (9100
rad), instead of the prescribed dose of 130 cGy (130 rad).
The licensee stated that such a dose may induce a hypothyroid state
requiring the patient to take thyroid hormone.
Cause or Causes--The wrong dosage was administered on the
assumption that the patient was prescribed a whole body thyroid scan
for a cancer metastatic disease evaluation.
Actions Taken To Prevent Recurrence
Licensee--Procedures for scheduling a whole body scan for thyroid
cancer metastases were revised to include a detailed patient
preparation and history.
[[Page 25883]]
The revised procedures required that the approving radiologist sign the
I-131 administration policy before ordering a radiopharmaceutical. In
addition, the nuclear medicine technologist attended a continuing
education program at San Francisco General Hospital, which included a
segment on the effects of studies involving therapy dosages.
State Agency--The State Agency conducted numerous follow-up
inspections to ensure that the licensee's actions taken to prevent
recurrence had been implemented.
This event is closed for the purpose of this report.
* * * * *
AS 97-4 Radiopharmaceutical Misadministration at Tuomey Regional
Medical Center in Sumter, South Carolina
One of the AO criteria notes that a medical misadministration that
results in a dose that is equal to or greater than 10 gray (Gy) (1000
rad) to any organ (other than a major portion of the bone marrow, to
the lens of the eye, or to the gonads) and represents a dose or dosage
that is at least 50 percent greater than that prescribed in a written
directive will be considered for reporting as an AO.
Date and Place--December 11, 1996; Tuomey Regional Medical Center;
Sumter, South Carolina.
Nature and Probable Consequences--A patient was prescribed a dosage
of 74 megabecquerel (MBq) (2.0 millicurie [mCi]) of iodine-131 (I-131)
for a treatment of Graves disease. However, the patient was
administered a 388.5 MBq (10.5 mCi) dosage of I-131. As a result, the
patient's thyroid received a dose of 40,400 centigray (cGy) (40,400
rad) instead of the prescribed dose of 7700 cGy (7700 rad).
The licensee stated that the administered dose of I-131 to the
patient's thyroid is not expected to have major health effects.
Cause or Causes--The wrong dosage was administered to the patient
because the written order for the I-131 procedure was misread by the
administering technologist.
Actions Taken To Prevent Recurrence
Licensee--The licensee will have the written order on hand before
ordering radiopharmaceuticals from the pharmacy and will have a second
person verify the dosage before administration to the patient.
State Agency--The State Agency accepted the licensee's report and
corrective action as appropriate. No further action was requested.
This event is closed for the purpose of this report.
* * * * *
Dated at Rockville, Maryland this 5th day of May, 1998.
For the Nuclear Regulatory Commission.
John C. Hoyle,
Secretary of the Commission.
[FR Doc. 98-12390 Filed 5-8-98; 8:45 am]
BILLING CODE 7590-01-P
