PM-3A Design and Construction: Rapid Pace to Fulfill a Need
The U. S. Navy began intensive involvement in Antarctic research missions during 1955 in preparation for the International Geophysical Year. The Department of Defense assigned the Navy the responsibility of maintaining and supplying the logistical needs of permanent research stations located in Antarctica. The assignment was based on the fact that the Navy had the experience and the manpower needed to handle the task.
Soon after receiving the assignment, the Navy conducted a study that concluded that nuclear power had some highly desirable advantages that led it to be considered as the power supply of choice for the research stations.
Antarctic Nuclear Advantages
The study recognized that the large majority of the funds spent on polar expeditions went to manpower and logistical support, far outweighing the amount of money spent on direct scientific research. Of the money going to logistical support, more than half was consumed in the effort of transporting fuel oil.
The cost of fuel oil for use at an Antarctic research station was estimated to be between $1 and $3 (1960 dollars with no escalation assumed for inflation) depending on the specific location of the station and the time of year that the fuel delivery occurred.
The cost of storing fuel was also considered to be quite high, due the the fact that the fuel required provisions for heating to prevent solidification. The tanks that could be built on the station were necessarily limited in size, restricting the amount of power that could actually be produced by a fuel oil operated generator during the time between possible shipping times. (The weather in Antarctica absolutely prevents fuel oil shipments during part of the year.)
The researchers also took into account the benefits to the research effort of having a larger quantity of electrical power available and the potential safety benefit of using electrical heaters rather than oil heaters. (With fuel oil systems, the efficiency advantages of direct heaters are significant compared to that of producing electricity in an engine powered generator and then converting that electricity into heat.)
Finally, the study also concluded that using nuclear power in such a remote region would be an excellent demonstration of the President’s new Atoms for Peace program, showing how the new technology could improve the well being of people located far from civilization.
Amazingly Rapid Development
Based on the results of the study and on high level discussions at the Atomic Energy Commission and testimony before the Joint Committee on Atomic Energy, Congress authorized and funded the design and construction of a nuclear power station for McMurdo Station, Antarctica in August of 1960.
The Martin Company – later known as Martin-Marietta, now known as Lockheed-Martin – was awarded a contract for $4,086,148 on August 15th 1960. (The Atomic Energy Commission had already begun contractor bidding and negotiations in anticipation of Congressional approval.)
As soon as the contract was signed, Martin began purchasing plant components. By early fall 1961, the plant had been assembled at the company’s Baltimore, Maryland Environmental Testing Building and tested in all phases short of actual operation with a reactor heat source. The reactor was assembled and tested in a separate facility.
On November 3, 1961, all of the plant modules were loaded onto the USS ARNEB (AKA-56) in Davisville, Rhode Island to begin the journey to McMurdo. On December 13, 1961 the ship arrived at McMurdo and began unloading. By December 29, all major components had been pulled by sled to the reactor site.
Between January 1 and March 1, 1962, the plant was assembled by a team of contractors and military technicians. On March 4, 1962, the plant reached initial criticality. The last ship for the winter left, leaving behind a team with the responsibility for testing and operating the plant.
Slow Testing and Turnover
Review that time line again. Congress approved funding in August of 1960, and the plant achieved initial criticality in March of 1962, just 18 months later. Between those two dates, the contractor designed the plant, purchased or built all plant components, obtained AEC approvals, constructed the plant once in Maryland, disassembled the plant, loaded it onto a ship, unloaded it in one of more remote locations in the world, constructed the plant again and brought it to its first criticality.
For its part, the Navy assembled and trained a team of volunteer technicians that were willing and able to do the job of building, testing and operating a nuclear plant in a place where it is dark six months out of the year. The pace of those operations judging by today’s nuclear standards is simply mind boggling.
However, once the above successes occurred, reality set in. The plant, a completely new prototype designed and built less than a decade after the first nuclear power plant in the world went critical, had some start-up difficulties.
The most difficult and time consuming problem was achieving a successful containment leak test. As is often the case for those tests, the cause of the consternation was the sealing of cable penetrations. Finally, after the fourth try, the test was completed in June, 1962.
Other persistent problems occurred with electrical noise causing source range instrument fluctuations (readers who are not nukes please forgive us, this terminology might confuse you, but it will be quite familiar to those with knowledge of typical nuclear plant problems in the early years), spurious scrams caused by fluctuations in instruments with one out of two logic and control rod drive mechanism power supply failures.
On October 7, 1962, a flash fire occurred in the containment tanks caused by a hydrogen accumulation from the radiolytic decomposition of primary shield tank water. The fire damage was largely cosmetic, the only major damage was to the control rod drive mechanism coil cans, which were collapsed around the holding coils and indicating mechanisms. This damage, even though minor, prevented reactor operation. Procedures and equipment modifications were instituted to ensure that hydrogen would not build up to an explosive concentration again. (According to the official records, that was the only fire that occurred at the plant.)
Even though the initial contract specified that the Navy would accept the plant from the contractor during the summer of 1962, the Navy negotiators decided that too many items remained to be fixed before the turnover could occur.
Throughout 1962 and 1963, the plant continued to operate with occasional shutdowns for testing, repairs and modifications under the supervision, ownership and control of the contractor. Each time the contractor got ready to turn the plant over, the Navy found more deficiencies that it asserted were the contractor’s responsibility to fix under the original contract.
Finally, in March of 1964, the Navy agreed to a negotiated settlement under which it assumed responsibility for the plant subject to the completion of several identified repairs. The Navy reluctantly agreed that some of the plant’s deficiencies were not the contractor’s responsibility and that their modification needed a new contract. The AEC agreed to pay for part of the needed modifications to systems including the nuclear instrumentation and reactor safety systems, the control rod drive mechanisms and the development of a new core.