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KCP PM 147 Contamination Time Line
Summary of Report of Investigation of Pm 147 Contamination, February 10, 1989, Kansas City Plant, Kansas City, MO, Published September 1989
Click here to see the complete Report of Investigation of Pm 147 Contamination, Feb 10, 1989
Background
The Kansas City Plant (KCP) requested (via a series of telephone calls only) Oak Ridge National Laboratory (ORNL) Isotope Products Division to provide the Pm 147 (Promethium) sources with 10-590 millicurie activities in 1974. No formal specifications were documented, but per the verbal agreement by both parties, ORNL provided experimental sources of Pm 147 to KCP.
The two people who made these verbal arrangements at KCP and ORNL retired in 1982 and 1984 respectively. The process of fabricating the source from 1980-1989 was nearly identical to the process prior to 1980, according to ORNL.
ORNL never intended these sources to meet the criteria of ‘sealed’ sources, however, KCP assumed that they were sealed. Neither facility ever conducted tests to validate if they were sealed or unsealed.
In September 1983, a Pm 147 source fell from a counter top to the floor in the ORNL facility. The glass shattered and spread throughout the area, requiring extensive decontamination cleanup of the radioactive materials.
Where was Pm 147 going to be used by KCP?
In beta backscatter units located in the following areas:
- D456, FE-49 – Quality Engineering’s Non-Destructive Test Lab
- D842, BW-31 – Electronic Engineering Laboratory
- D423, BO-29 – Metrology Laboratory
- D33, FU-33 – Precision Pattern Assembly Area
- D436-97, FG-51 – Plating and Chemical Milling
What is Pm 147?
Pm 147 is a donut shaped source (200 millicurie) that surrounds an aperture specially created for KCP because no known commercial sources existed over 50 millicurie.
Fabricated by absorbing the radioactive material salt into a Vycor glass preforms through a series of soaking and heating processes (Vycor is a ‘thirsty glass’ that absorbs chemicals). The glass is then placed into a platinum source holder with adhesive and attached to an aperture with screws (all supplied by KCP) undergoing additional heating processes for the adhesive. After verifying that the radioactive transferable activity was less than 500 dpm (disintegrations per minute) with swipe testing, this entire unit was placed into a lead-lined jar and packaged for shipment with handling instructions for KCP.
The shipping document provided by ORNL:
“Warning: This shipment must not be opened until adequate health and safety measures are taken (such as placed in a hood, glove box, cell) so as to protect the handler from excessive exposure to the body as a result of radiation and/or contamination. KCP was inspected and all specialize safety measures (clothing, shielding, gloves, etc) were available for the employees who handled the Pm 174”.
- Millicuri: a unit of radioactivity equal to one thousandth of a curie. It means that amount of radioactive material which disintegrates at the rate of 37 million atoms per second
- Dpm (disintegrations per minute ) is the number of atoms that have decayed, not the number of atoms that have been measured as decayed. Dpm is commonly used as a measure of radioactive contamination.
- 1 millicurie = 2,200,000,000 disintegrations per minute
What happened when the Pm 147 arrived at KCP?
Industrial Hygiene Department personnel unpackaged the sources and wiped them down with alcohol soaked cotton swabs to test for leaks. The transferable activity was measured and compared against the ANSI standard measurement only, disregarding the remainder of the code because the Pm 147 was considered experimental.
(Code of Federal Regulations, Title 10 CFR (NRC) Subpart B, Radiation Safety Requirements, Paragraph 34.25, Leak Testing, Repair, Tagging, Opening, Modification and Replacement of Sealed Sources. Tests of sources which reveal 0.005 microcurie or more of removable radioactive material shall be considered to be leaking and removed from service to be repaired or disposed)
Every 6 months, the same test was to be performed by the hygienists. (See pages 49-50 for listing of all Pm 174 sources received by KCP)
Time Line of Events
Department 456
Available Testing Equipment: Radiological Monitoring Equipment: Victoreen Model 444
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Year
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Month/Day
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Event
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1983
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December
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Shipment of Pm 147 found to be contaminated
(during development of a probe for Mound)
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1984
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June
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Probe filled with Pm 147 was “knocked over” causing a section of material to break loose, the clean up methods undocumented (Exhibit 2)
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1984
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July
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Two Pm 147 sources were ‘chipped and falling apart’. The material was chipped away from the platinum source holders and disposed of by Waste Management (D187) (Exhibit 3)
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1984
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July
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A Pm 147 source was falling out of the platinum holder, so it was replaced
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1988
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April
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Loose radioactive contamination discovered on apertures and on a tabletop
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1988
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June
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Loose radioactive contamination discovered on apertures and on a tabletop (Exhibit 4)
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1988
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October 19
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Pm 147 source created by ORNL registered over the desired 500 dpm. KCP instructed ORNL to ship as is
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October
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A 200 Millicurie source arrived, tested for leaks, and finding none, loaded into a probe and shipped to D33
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1989
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February 9
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Confirmed radioactive contamination of the elastic bands of the KCP employee’s left and right ring dosimeters. Dosimeters confirmed readings of radiological exposure. The low-level beta energy range of Pm 147 cannot be detected by the dosimeters worn by the employees. The radiological exposure read was the result of the amount of exposure time to the radioactive source
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1989
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Feb 10 (Friday)
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Radiology readings were detected during a routine survey on an X-ray fluorescence machine cabinet by a Vicrorean Model 471 Meter
The same area was surveyed using the Eberline 530, contamination was found on the stool, tabletop and on the hand of the employee
Employee was informed to notify DOE-KCAO
Laboratory was put into restricted access
The shoes of all 11 employees were tested, 5 were positive for radioactive contamination
The shoes were wiped down with alcohol (swipes were later sent to the KCP Health Physicist consultant for determination of the radioactive material (read on the following Monday)
The area was determined to be uncontaminated at 11:40 am
All areas of the plant that used radioactive materials were isolated ed at 3:50 PM.
A suggestion was made that all employees were to wear respirators, associated dosimeters should be collected and air handlers were to be shut down.
At 5:15 pm, the area was sealed off for the weekend, keys were collected and signs posted, and the air handling equipment was turned off.
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1989
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Feb 13-17
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Discovered that the air-handling unit had not been shut off, instead a baffle had been installed in the ductwork that supplied the NDT laboratory.
Airflow grills between D456 and D435 were monitored
Stairwell connecting D456 and D456 office area was monitored
Contamination discovered outside of D456
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1989
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Feb 14
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The inside of a shoe worn by a janitor was confirmed to be contaminated
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Metrology –
Available Testing Equipment: NONE
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Year
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Month/Day
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Event
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1988
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April
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Loose radioactive contamination discovered on apertures
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Department 33
Radiological Monitoring Equipment: NONE
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Year
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Month/Day
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Event
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1978
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April
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Beta Backscatter Unit (GT1014) began operation
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1985
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February
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Replaced the plastic apertures with metal apertures on the beta backscatter unit (last time changed)
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1985 – 1986
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Backscatter equipments sat unused, containing a full probe of Pm 147
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1987
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February
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Probe loaded with Pm 147 crashed into the beta backscatter unit during calibration.
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1988
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October
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Probe loaded with 200 Millicuries of Pm 147 received from D456
Operators noted the aperture/source holder was not seated properly –
Attempted to tighten screws
Removed the aperture from the probe assembly and replaced it
Probe was relocated into the beta backscatter fixture
Next day, opened the probe nose assembly and lost a screw that attached the apertures to the source holder assembly
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1988
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December
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Probe crashed into the beta backscatter unit
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1989
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January 3-13
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Probe crashed into the beta backscatter unit’s scale actuator, breaking the beryllium window
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1989
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January
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Beta backscatter unit is repaired, replacing the corroded electrical connections and replacing a cooling fan. The integrity of the Pm 147 was questioned, but was told it had just been received. In reality, it had been received in Oct of 1988
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1989
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Feb 13
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Loose radioactive contamination was discovered in the beta backscatter unit of room E with readings up to 15,000 cpm (where people were still working).
Floor and area adjacent to the Beta backscatter unit was found to be contaminated in excess of 2,500 cpm
Area was secured at 11:50 am
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1989
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Feb 14
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Crews from Sandia (SNLA) and Los Alamos National Laboratories (LANL) arrived to bag and seal the source probe of Pm 174 (dressed in full gear with high efficiency respirators).
Inside of the probe transfer cap was swipe tested and found to be 230,000 cpm.
Cardboard box used to transfer the probe was swipe tested and found to be 70,000 cpm inside and 3000 cpm outside
All items were bagged, sealed and left in the area
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D842 basement BQ-28
Radiological Monitoring Equipment: NONE
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Year
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Month/Day
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Event
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1989
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Week of Feb 13
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No contamination was found (the area used a similar Beta backscatter unit but a Pm 147 probe had not been used since 1/16/88)
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Testing Equipment (Purchase/Calibration) Time Line
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Year
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Month/Day
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Event
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Unknown
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Unknown
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Victoreen Models 440 and 471 – used to detect swipe tests for low-level beta sources, unfortunately, this equipment could not detect low-level beta sources.
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1974
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March
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Purchased Eberline E530 meter
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Prior to 1980
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Purchased HP260 probe (Exact date unknown)
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1987
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1987
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E530/HP260 were first calibrated for Pm 147
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1988
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June
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Victoreen 471 was calibrated for the first time (still only able to detect 61% of the spectrum that the E530/HP260 can detect)
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Testing Time Line
Prior to 1985 – the survey instruments at KCP were not adequate to test the sources for contamination
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Date(s)
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Event
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Late 1985-Feb 1986
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Eberline E530 meter/HP260 probe was first used to test leaking radioactive sources at KCP (Exact date unknown), but since the testing unit was not calibrated for Pm 147, nothing was found
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March 1986- January1988
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No leak tests conducted by the Industrial Hygiene Department on Pm 174 sources due to funding and manpower constraints
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Feb 15, 1988
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Rumors of leaking Pm 147 prompted health checks
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April 1988
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First time the E530/HP260 testing units were used for leak testing
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January 1989
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The swipe samples taken from the contaminated shoes of the employees of D456 taken to the Health Physicist consultant at KCP to determine the type of radioactive contamination.
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Contamination Notification Time Line by KCP
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Date(s)
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Event
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Between 2/14 and 3/1
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KCP employees were kept up to date of the clean up progress through in-plant publications and televised interviews
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Feb 15, 1898
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Contact was made to the following agencies of the Pm 147 incident:
EPA Region 7 Waste Management Division
MODNR Emergency Response Commission
MO Dept. of Health, Radiological Health Division
NRC, Chicago Office
KCP Medical Department
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Feb 18, 1989
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Contact was made to the following agencies of positive bio assays:
EPA Region 7 Waste Management Division
MO DNR
MO Dept. of Health, Radiological Health Division
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Feb 20, 1989
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Notification to KCMO Health Department of off-site contamination
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Clean Up Time Line
Industrial Hygiene staff of KCP was not equipped or trained to clean up radioactive materials, so additional teams were formed
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Date(s)
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Event
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Feb 14, 1989
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Crews from Sandia (SNLA) and Los Alamos National Laboratories (LANL) arrived to bag and seal the source probe of Pm 174
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Feb 14, 1989
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Allied Signal team of health physicists (3 LANL, 2 SNLA and 1 DOE AL individual)
Intent: asses the spread of radioactive contamination, conduct minor decontamination activities and advise the KCP management team of situation recovery
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Feb 15, 1989
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Industrial Hygiene department requested 24-hour urine samples of the nine KCP employees who were involved with Pm 147 sources
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Feb 16, 1989
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Samples shipped to Eberline for analysis
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Feb 16, 1989
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Due to the widespread level of contamination, Rocketdyne Division of Rockwell International Corporation at Canoga Park CA was contracted to complete the decontamination actives.
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Feb 18, 1989
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Eberline confirms positive tests for radioactivity of 4 employees from the urine samples, varying from 13-66 picocuries on a count of 100
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Feb 18, 1989
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Positive contamination of 4 employees found and whose homes were to be surveyed by 3 teams. Specific areas of the homes were identified for the survey. A second survey was to be completed on each individual’s vehicle. 3 of the 4 employees had their homes surveyed starting at 7:40 pm. A pair of slippers was tested at 500-600 cpm. They were bagged tested further testing. The 4th employee was provided a bioassay bottle for the following day.
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Feb 19, 1989
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The slippers were not found contaminated with Pm 174 from Feb 18, the readings now down to between 100-200 cpm, were attributed to radon.
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Feb 19, 1989
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The home of the 4th employee was surveyed. Loose radioactive contamination was found within the first hour
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Feb 20, 1989
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Eberline reports that the positive readings of the 4 employees were in error, further testing of the samples did not find any evidence of radioactive contamination
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Feb 20 – March 9
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Rocketdyne Team completes decontamination
Collected and analyzed swipe samples and air particles and found them to contain Pm 147 (Exhibit 5)
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Feb 22, 1989
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Decontamination of the 4th employee’s home was completed.
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March 1, 1989
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4 Pm 147 sources, two assembled beta backscatter probes with Pm 147, 1 Pm 147 source holder and aperture from D33 and D456 were sent to SNLA by Rocketdyne
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March 3, 1989
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The original urine samples of the 4 employees were divided and sent to the DOE, Idaho Operations Office, Radiological and Environmental Services Laboratory and to Eberline for result comparison. Both found the samples to be within normal limits.
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March 8, 1989
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Rockwell International positively identified samples contaminated by Pm 147 from KCP
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March 20, 1989
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A total of 97 employees who were tested for Pm 147, no radioactive contamination found
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Rocketdyne Contamination/Clean Up Report Summary
All seven sources had detectable and spreadable contamination, appearing to be losing Pm 147; the coatings were flaking off, the aperture on one source was tightened to the point of crushing the Pm 147 glass and causing fine, free dust particles, and one source was gouged, destroying the integrity of the coating.
The 1988 source (the one that was 200 millicurie that KCP said to ship ‘as is’) was highly contaminated and leaking, and a chip of the glass was missing.
Table 3. Samples and Swipe Data
Survey team identified the following areas as contaminated:
- Department 456 Non-Destructive Laboratory
- Department 456 mezzanine offices (An open office area containing a manager’s office, secretarial area, bull-pen desk area for 9 workers)
- Department 435 X-Ray
- Department 33 Inspection
- Backscatter device
- Sub Floor Tiles
- Filters from the air handling system
- 1 Employee Apartment
A total of 283.36 cubic feet of contaminated materials, classified as radioactive waste, was removed
A water line riser was knocked off and flooded D33 during the decontamination process. The water was allowed to flow into the drain by Rocketdyne.
Contamination started in D456 and once airborne, the Pm 147 was deposited on hard surfaces and then spread as it deposited on the clothing, hands and shoes of the employees. The probe with the loose fitting that was transferred from D456 to D33 (October 1988) further spread the contamination. Once in D33, the crew released the contaminated materials during the installation process into the beta backscatter unit.
The procurement process was mishandled, inventories unregulated and un-monitored. Some of the sources we left uncapped in the storage cabinet contaminating other sources, the cabinet and the Strontium 90 and Thallium sources as well. Transportation between receipt and between the various offices was lax, often using cardboard boxes or plastic bags, and sometimes without any covering of any kind.
Workstations where the Pm 147 was handled did not have exhaust hoods or glove boxes. The facility was not a negative pressure facility. Janitorial containment checks were never conducted. No protective gear was worn. The storage facilities were inadequate. No special precautions were taken in regards to the integrity of the sources upon receipt.
The whole body badge worn by the employees was ineffective in detecting Pm 147 contamination based on the position in which they were located.
The ring dosimeters contained a TLD chip, making them insensitive to Pm 147, the only reason they contamination was found was due of the length of exposure time. Eberline knew this information but he did not notify KCP of the findings immediately.
Industrial Hygiene staff was not equipped or trained to clean up radioactive materials, yet they assisted the staff of each area in decontamination when a spill occurred.
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