Citation: OPERATION CROSSROADS, RADIOLOGICAL DECONTAMINATION OF TARGET AND NON- TARGET VESSELS Part 2 pp. 13-18
SAN FRANCISCO NAVAL SHIPYARD
SAN FRANCISCO CALIFORNIA
11 September 1946
NAVAL SHIPYARD NOTICE No, 244-46
Sub: Vessels Arriving from Bikini – Instructions Governing Special Tests.
1. The following instructions will govern relative to the special teats to be conducted by the San Francisco Naval Shipyard on ships employed in the Bikini operation:
1. Procure funds and originate Job Orders.
2. Follow up work procedures developed, smoothing same out, and put into such form as may be promulgated to other activities.
3. Compile all data necessary for the development of such reports as may be required from time to time.
1. Develop work procedures in accordance with existing and subsequent instructions.2. See to it that ships have radiological, clearance when they enter yard.
C. Industrial Relations
1. In consultation With Production, disseminate instructions relative to safety precautions.
J. W. FOWLER
DJBT: CO, OH, OF, CF
[Page 14 posted]
REPORT NO. 2
EXPERIMENTAL WORK, SAN FRANCISCO NAVAL SHIPYARD
SAN FRANCISCO, CALIF.
SECOND REPORT 16 September 1946 – INVESTIGATION OF RADIOACTIVITY of Ships from Bikini at the San Francisco Naval Shipyard starting 5 September 1946.
A First Report has been made on 6 September describing the first day of inspection for radioactivity of the USS LAFFEY DD724, drydocked in Ship Repair Dock ARD-32.
This Second Report is intended to describe chronologically subsequent events, tests, and results. At the outset it can be stated that the “Ships from Bikini” have been cleared by the monitors for all work that does not involve portions of the ship in contact with salt water. On all Bikini ships at San Francisco Naval Shipyard accordingly, all repair work has been initiated except work on the parts of the ships touched by sea water. This work, held in abeyance, will be started as soon as a monitor can be provided to work with the Shipyard in inspecting, monitoring, and issuing necessary precautions for each job. The working procedures for these jobs is dependent upon conclusions found as a result of the tests herein described.
The essential danger encountered by the presence of the radioactive ships is RADIATION POISONING of workers, which does not produce symptoms that can be detected for a long time after the initial poisoning. Radiation poisoning is effected by radioactive particles acquired in the blood, by eating, by breathing, or through an open wound.
Since even relatively minute amounts of radioactive material in the blood are likely to be harmful, it is apparent that elaborate and painstaking precautions must be taken to avoid “contamination” of workers with radioactive particles.
Accordingly the following measures were taken by this Yard:
(1) Detailed safety instructions for Yard men working on the hull or salt water connections of “Bikini Ships” have been issued.
(2) Wetting down of the hull of the LAFFEY has been continued four times daily to keep dust down to a minimum.
Google map location of building 103
(3) Submarine Base, Barracks B, Bldg. 103 has been set up as a “Changing and Decontamination Center” for Yard workmen. A large room at the East end of the building has been set aside as the “Contaminated Room”. Here at night Yard workmen who had been working on any Bikini Ships, completely disrobe and put all their clothing in sealed off lockers. (It would be desirable not to use this clothing again until it had been monitored for radioactivity but the fulfillment of this desire will depend on the amount of available clothing and the number of available monitors). The workers, now stripped of all clothing, walk down a strip of linoleum to the shower room where they are instructed to scrub thoroughly, especially under their finger nails. The men are told to scrub even the locker keys that they took with them from the “Contaminated Room”. The workers then dry themselves off and walk on a strip of linoleum to the West end of the building where a “Clean Room” is set up. Here the worker puts on his street clothes and leaves the building, going directly from the Clean Room into the street. In the morning workers go directly into the Clean Room at the East End, remove their street clothes, leave Clean Room, and out on working clothes, either issued to them from an Issue Room in the central portion of the building or taken from lockers in the Contaminated Room. At lunch time workers are instructed to wash their hands and face thoroughly and they eat lunch at tables set up in the “Contaminated Room”, all precautions being taken to avoid contact with any possible contaminated material. Workers are not permitted to reenter the Clean Room until they have had their shower at night.
On Friday, 6 September 1946, the day after the first inspection of the LAFFEY, it was desired to remove sand and dirt on the bottom of the drydock. Lt. Comdr. Turnbaugh called Capt. Walsh for advice. Capt. Walsh advised that the dock could be washed down allowing mud to flow into the Bay. The drydock was accordingly cleared of mud. Men doing the job were properly outfitted in safety clothing although the material handled was declared free of radioactivity.
The following three working days were spent setting up safety rules and procedures and preparing for further tests.
On Thursday, 12 September 1946, a sandblasting test and a burning test on salt water piping were conducted to determine the safety of these operations. The sandblasting test started at 1100. Present were Navy Medical Officers, Capt. W. E. Walsh, and Lieut. W. A. Chadbourn, Dr. F. H, Rodenbaugh, Army First Lieutenant C. R. Calloway, all monitored in the First Report. Also present was Dr. K. G. Scott, a physiologist from the Radiation Laboratory of the University of California, and Mr. C. J. Rosati, a chemist from the Industrial Hygiene Laboratory of the Mare Island Naval Shipyard.
For the sandblasting test a sandblaster and Lieut. Calloway were lowered in a skipbox alongside the ship. The test region was shielded from the rest of the dock by two large pieces of canvas, one hung on each side of the test region and suspended from lines between the LAFFEY and the ARD. The area to be sandblasted was first wetted down and then given the usual blasting with a combination of sand and water. Lieut. Calloway had with him a fairly large instrument or machine cleaner with a filter for collecting dust particles.
It bore the name “FILTER QUEEN” and was put out by the Heathmer Co. of Chicago. Several pieces of filter paper served as a filter.
During the sandblasting operation, Mr. Rosati from Mare Island set up on the main deck of the drydock, near the test region an “Electrostatic Dust Precipitator” manufactured by the Mine Safety Appliance Co. of Pittsburgh. Air was sucked in through a small metal tube in the center of which was an insulated wire. A high voltage put
between the wire and the tube caused dust particles in the incoming air to be deposited on the tube. The metal tube was lined with a filter paper in this test so that the collected dust particles could be investigated. The filter was changed several times during the test.
At 1130 portions of the saltwater piping were measured with the radiation counter and a sample piece was selected. This was unbolted from the ship, the open ends on the ship being blanked off. The sample piece was taken to the ship’s shipfitter shop. A burner and Dr. Chadbourn, each wearing an oxygen mask, closed themselves in this compartment, and the sample piece of pipe was burned through, filling the compartment with smoke. The “Filter Queen” was used to collect dust samples. The operation started at 1340 and lasted 17 minutes. Adequate provision was made to rid the compartment of remaining smoke.
All filters “contaminated” during the day’s tests were taken by Dr. Scott to the laboratory for analysis.
On Friday, 13 September 1946, additional supplementary tests were Initiated by the yard, although none of the medical scientists were present.
First the sandblasting test was repeated using dust collecting apparatus with a much larger airflow capacity than before. Two standard ventilation blowers with rated capacity of 1000 cubic feet per minute were set up by Shop 17, the discharge end of each being heavily packed with a glass filter 2 inches thick. One blower was placed on the skipbox with the sandblaster. With a 6 inch intake pipe this blower circulated through the filter a measured 650 cubic feet of air per minute. The other blower was put on the main deck of the drydock in the path of the main dust stream. With a 5 inch intake this blower sucked in a measured 650 cubic feet of air per minute. This test was started at 1548 and run for 40 minutes.
On Saturday, 14 September 1946, these supplementary tests were resumed, Dr, Scott and Lieut. Chadbourn being present at 0900. Dr. Scott had previously sent the Yard some acetic acid and ammonium hydroxide. The Yard provided a 50 gallon mixing container and a reciprocating air pump for mixing operations.
A “decontaminating solution” was mixed at the Yard as follows:
25 gals, of water were placed in the mixing pot and 48 lb. of acetic acid powder was added. Ammonium hydroxide was then added until the acidity of the solution was reduced to the value pH 6.0. 34 lbs. of ammonium hydroxide was found necessary to attain this result. The solution was constantly agitated throughout the mixing operation.
The Yard opened up and blanked off a portion of the firemain having approximately 50 gal, capacity. Hose outlets were provided at each end, and the “decontaminating solution” was pumped through the blanked off section of firemain until it was entirely filled. Only about 30 gallons of solution was found required for this, indicating probably 20 gallons of sea growth in the pipe. This operation was completed at 1100 and the test scheduled to run 72 hours.
The original section of salt water piping (described in the First Report) sent to the Radiation Laboratory of the University of California was galvanized steel pipe and the solution devised was intended for steel, since it would chemically attack iron and loosen rust particles as well as dissolve marine growth. The sample of firemain selected was not steel however, it was a Copper-Nickel alloy (as is now standard for firemains) so the present test would be effective against marine growth only. Further tests on Copper-Nickel pipe are anticipated using a little sulphuric acid in the solution. Geiger Counter Readings taken at various places along the firemain were marked so that later readings will quickly determine the effect of the solution.
The burning test of Thursday was repeated by Dr. Chadbourn with a galvanized salt water pipe taken from a ship not at Bikini, the results to be used as a CONTROL.
In summary then,
The results of the tests started Thursday, 12 September 1946, have not yet been reported. It is from these results that decisions will be made on what work will be permitted on the external hulls of radioactive ships and instructions issued on how to handle, the various salt water systems of these ships.
Source: OPERATION CROSSROADS. RADIOLOGICAL DECONTAMINATION OF TARGET AND NON-TARGET VESSELS. VOLUME 2 , DNA ltr, 21 Apr 1982, THIS PAGE IS UNCLASSIFIED, DIRECTOR OF SHIPTECHNICAL INSPECTION REPORT. Radiological Decontamination of Target and Non-Target Vessels, VOLUME 2 OF 3.