A Small But Nagging Point

SIR Naval Prototype Plant rolled into containment sphere; March 20, 1954.  From brochure "The Seawolf Story" in Will Davis library.

SIR (Submarine Intermediate Reactor) Naval Prototype Plant rolled into containment sphere at West Milton New York; March 20, 1954. From brochure “The Seawolf Story” in Will Davis library.

by Will Davis

We’re coming up on another anniversary of the startup of the Shippingport Atomic Power Station in early December.  That plant was more or less a Navy plant (at least in terms of the NSSS or Nuclear Steam Supply System) built not for powering ships but instead for powering businesses and homes.  The move to get that done was rapid and fluid – and now there’s maybe a hint of evidence that it could have been a returned favor to Admiral Rickover.

The usual story of the Navy’s early prototype plants is involved here, since the plant that became Shippingport was to have been one of these.  In brief, the story goes as follows.  Soon after the end of the Second World War, the Navy picked right up on the idea of powering ships with nuclear energy.  In 1946 it signed a contract with Allis-Chalmers to study the Daniels Pile project at Oak Ridge, which was soon cancelled.  However, both a water-cooled nuclear plant project (Project Wizard) and a sodium cooled nuclear plant project (Project Genie) were soon undertaken as just two parts of a large Navy program to develop airless propulsion for submarines. (The others, such as Walter turbines based on German U-boat practice, or the Krieslauf atmosphere-independent diesel engine, didn’t work out.)

Now, this early history gets thrown out a whack a little bit if we look at some testimony that Admiral Rickover gave to the Joint Committee on Atomic Energy.  Rickover had two sessions with the JCAE in 1957 on the Naval Reactor Program and on the Shippingport Project.  During a discussion of the SIR or Submarine Intermediate Reactor, the sodium cooled submarine plant, Rickover said the following on the record:

“At the time we started working on the nuclear propulsion program, sir, we went to two equivalent approaches.  At that time, in 1947, we did not know which one would work.  As a matter of fact, at that time we thought sodium had a better chance of working than water.  Sodium had been chosen by General Electric for their power breeder at Knolls Atomic Power Laboratory.  Later on, when the Commission found that the design of the sodium-cooled power breeder was not going along well and the expense to build it would be too great, it was changed to a naval submarine project and we in the Naval Reactors Branch took it over.”  — Hearings before the Subcommittees of the Joint Committee on Atomic Energy – Congress of the United States  / Naval Reactor Program and Shippingport Project, March 1957, page 8.

SIR (later, S1G) prototype plant submergence tank.  Press Photo in Will Davis library.

SIR (later, S1G) prototype plant submergence tank. Press Photo in Will Davis library.

Now, I myself am a former Navy reactor operator, and I’ve never heard or read of the story of the SIR, later to be called S1G prototype plant, told the way Rickover told it to the JCAE in 1957. It seems clear that the Navy, from Rickover’s words, took over for the AEC a floundering project in order to help AEC obtain funding to bring it to completion (even of course if the reactor was not a breeder.)

Of course, these events that Rickover is describing would have been within a year or two after the end of the Second World War.  But, flash forward to 1953, the Navy decided in that year that with an enormous budget crunch ongoing (due to USS NAUTILUS expenses, jet aircraft, missiles and more) it was going to have to defer or cancel some important projects.  One of those projects was the Naval Reactors CVR project — the project to develop the nuclear power plant for an aircraft carrier.  Within that year, the AEC elected to take the whole development of that project and transfer it over to a new, civilian-faced but decidedly Rickover-run project called the Shippingport Atomic Power Station.  Complete continuity was maintained. There was no time was lost, and no talent dispersed.

Considering what a dud the sodium cooled reactor was turning out to be by 1953*, I myself like to think that the quick salvage of the CVR project was a returned favor to Rickover for helping save the sodium cooled plant project.  His closeness to and favor with the AEC and the JCAE would easily have allowed it.  Even if it wasn’t, what is remarkable is the extreme fluidity and ease with which projects in those days migrated between labs, the AEC, and contractors.  That would be a wonderful environment to still have today.

General Electric press photo airbrushed to show shielding tank for SIR, later S1G prototype inside 225 foot diameter spherical containment - the largest spherical containment ever built for a nuclear plant.  Press Photo in Will Davis library.

General Electric press photo airbrushed to show shielding tank for SIR, later S1G prototype inside 225 foot diameter spherical containment – the largest spherical containment ever built for a nuclear plant. Press Photo in Will Davis library.

* The SIR prototype, later the S1G when redesignated, eventually had to complete its trial run with its superheaters bypassed, since they were leaky.  This same thing happened to USS SEAWOLF, SSN 575, which then operated for several years not being able to get over 60% power because of no superheat.  Eventually SEAWOLF was repowered with a PWR NSSS (the Westinghouse S2Wa) and the prototype in New York was removed from the sphere, which was used for another prototype later.  The Navy never looked at any sort of sodium cooled plant again.

ANS member Will DavisWill Davis is Communications Director and board member for the N/S Savannah Association, Inc. He is a consultant to the Global America Business Institute, a contributing author for Fuel Cycle Week, and he writes his own popular blog Atomic Power Review. Davis is also a consultant and writer for the American Nuclear Society, and serves on the ANS Communications Committee and on the Book Publishing Committee. He is a former US Navy reactor operator and served on SSBN-641, USS Simon Bolivar.

14 thoughts on “A Small But Nagging Point

  1. Mike Staehle

    As a machinest mate I was a reactor operator on S1W and also in 1957 worked on the S1G,(575) epithermal reactor and others since. In my opinion the SEAWOLF system was by far the best for a number of reasons: proven technology, cheap available fuel, half the size, nearly twice the power, super heated steam,was or could be effectively a fast breeder, the primary coolant (sodium)was the only moving part in the primary system, no shaft or rotary seals in the primary system, under 50 psig primary pressure, etc., etc. Tube cracking in the superheaters, tritium from fission of Na, other developmental, but essentially minor problems, existed of course; I could go on and on, but even though the maratime industry learned not to build “Scotch Boilers” years ago; politics prevailed. None of the early problems could not have been readily solved. I would enjoy reminiscing with those interested. Cheers, Mike Staehle, Captain (Ret)

  2. Charles Bergeron

    RE: Robert Field ‘can do’ spirit comment.
    Not only was the Nautilus a quick success – the whole HGR program during the cold war was like few other military successes.
    Approximately 100 nuclear subs built. The last 637 class sub I was Bettis Joint Test Group member for at Newport News went from keel laying to sea trials in 2 yr 4 mos. (I think record still stands!) I spent ’67 to early ’70 in the field for Bettis and was JTG, JDG or BTA on over 20 subs.
    I would love to see America have that capability again – BUT not need it!!

  3. Charles Bergeron

    RE: my last comment! I think I missed that many comments I just read actually predated my first comment.
    Sorry for accusing anyone of missing a point!

  4. Charles Bergeron

    I see a lot of you missed the point concerning reactors and sodium of my earlier comment. Sodium was not pushed on Rickover. In the very early days of reactor design, it was the best candidate for a small power reactor. It was the invention of Zircaloy at Bettis that allowed light water to be used as a coolant and moderator and still be an efficient power reactor. I’m certainly not a Bettis man sticking up for Knolls – and definitely agree that sodium cooled reactors are maintenance nightmares!
    The Rickover – Sodium stories are consistent with the other numerous “myths” that grew up around HGR. He was amazing at playing people and letting them go – to sow their “stories”. He loved to play human nature – and loved to bluff playing poker!! He had no patience for setting the record straight later – so the stories persist.

  5. Stephen Maloney

    Last year, American Institute of Physics (AIP) published a high-level historical piece in August 2015 covering Milton Shaw’s role at AEC’s Reactor Development and Testing Division (RDTD). It focuses on the mid-1950s break between Naval Reactors and AEC over reactor design strategies.

    There are some interesting links including Admiral Rickover’s 1979 testimony before the Subcommittee on Energy Research and Production of the Committee on Science and Technology.

    It’s available at http://scitation.aip.org/content/aip/magazine/physicstoday/news/10.1063/PT.5.2029

  6. Charles Bergeron

    Shippingport was more a favor from HGR to the Govt. (Ike) than the other way round. Ike asked HGR for a fast project to be completed for his “Atoms for Peace” initiative.
    I worked for Bettis Atomic Power Labs (Naval AEC) and later for Stone and Webster Eng Corp. [SWEC did the Plant design and construction.] I knew the major players in the Shippingport Project very well. The Shippingport reactors were the prototypes for Aircraft Carriers. The Enterprise used Submarine sized reactors, which required 8 reactors. The later Carriers [Nimitz] used the descendants of the Shippingport size and only required 2 reactors.
    Both the sodium and water cooled submarine prototypes worked out.
    The water cooled type was a bigger gamble in the early days due to neutron absorption and was made possible by the invention of Zircalloy at Bettis.
    The final nail in the sodium reactor use on submarines was the difficulty in preventing steam pipe failures due to Na or NaK leakage. Seawolf plant was removed before this happened at sea. Would have killed all on board!
    Cool trivia! The last Shippingport core was a light water breeder reactor!! At the time of design it was thought that this was not possible. The head of Bettis core design [Dr. Connor] and HGR did it as a point of technical pride and to keep interest up in future nuclear fuel cycle research.
    And I didn’t mention the Seawolf Hg tertiary loop design fiasco or my conceptual design of a sub with no rotating propulsion equipment. The latter became the fictional “Red October”.

  7. David Moses

    When I worked at Bettis (1973-1979), the story I heard, which may be apocryphal, was that when Admiral Rickover was approached by Congressmen on why he had canceled the SIR, he took them out on a Navy earge at Norfolk and had his crewmen throw cans of sodium into the water and then had them shoot the cans with rifles. When the sodium exploded, he reportedly turned to the Congressmen and said “I suppose if the ocean was made of sodium you’d want me to build PWRs?”

  8. Robert M. Field

    Maybe in the twilight of the Cold War, we should take a moment to reflect on what a fantastic success was the USS Nautilus (SSN-571).
    First Sustained Chain Reaction (FSCR) 2 December 1942 (Chicago Pile 1)

    SSN-571 Hull Laid Down (HLD) 14 June 1952

    SSN-571 Launch 21 January 1954 (HLD plus 586 days, FSCR plus 11 year, 2 months)

    SSN-571 Retired 3 March 1980 (26 years, 41 days)

    An incredible tribute to those who made it happen, to the ‘can do’ spirit of the American people.

    Robert M. Field
    Busan, Korea

  9. Richard Soderholm

    I know nothing about the design background of the SIR, but have some heresay knowledge of the Seawolf Sodium days.
    I trained at S3G in 1960 while D1G was under construction in the Horton sphere.
    Following, I taught Basic course at NPS, Mare Island, commissioned Plunger SSN 595 at Mare Island and took it to Pearl Harbor, was Engineer Officer on SSBN 611, and then SubRon 10 Engineer, which included Nautilus, Seawolf, Skate and Skipjack.
    On SSBN 611 I had several MMs and EMs from Seawolf sodium days who talked about it.
    The Subron Eng Office had Seawolf manuals from both plants, which I read.
    I also rode Seawolf every month when possible on short trips, plus Admin and Operating Inspections.
    The sodium cycle is very attractive to designers, high thermal efficiency and low pressure. I believe the S2G loop pressure was 40 or 50 psi, with a gas filled pressurizer.
    Required shore power to heat the loops when shut down.
    High radiation remained after shutdown. I believe no reactor compartment entry during the operating year. Example: Multiple spare thermocouples installed, so just rewire a terminal strip outside of RC to repair.
    We did not have the metallurgy for sodium-steam heat exchangers welding. Things kept cracking.
    When converted to S2Wa, they had duplicate Nautilus long lead time components available, RV and SGs. They used two speed RCPs instead of the Nautilus variable speed pumps. The RO controlled on Th instead of Tave, to keep steam pressure high. The SSTGs had two generators on each shaft, one for ship service 480v, and one for variable voltage for the sodium electromagnetic pumps. These RCP generators were fixed at 480v for the new RCPs.
    Some years later, as a Shipyard Officer, I led the conversion of Seawolf for its’ intelligence work. No change to the power plant, but weeks of testing.
    Concerning Shippingport:
    You mentioned the early NRC designations, SIR (Submarine Intermediate Reactor), and STR (Submarine Thermal Reactor). They also had SFR (Submarine Fleet reactor, later S3W and S4W, depending on the SG design). SFR was half the power of the STR. I believe the S3G/S4G (Triton) was called SAR (Submarine Advanced Reactor), either because of its’ higher temperatures or its’ twisted fuel elements.
    I read someplace there was also a (Westinghouse) Bettis LSR (Large Ship Reactor). Probably heard this at Bettis. When the ship was not funded, it became Shippingport reactor, but with a commercial steam plant. Eisenhower pushed an “Atoms for Peace” program that started and stopped in those years.
    I attended Bettis Lab training in 1961, (SSN 595 crew) and we visited Shippingport.
    See: http://www.alternatewars.com/BBOW/Nuclear/US_Naval_Reactors.htm
    Anyone with better data should correct this.

  10. David Flomerfelt

    Will, interesting story especially about the German Walter turbine submarine, never heard of it before this. You mention the Seawolf prototype at West Milton, NY. Having trained on S3G in 1969, one of the sea stories we heard was the S1G reactor was buried there at the West Milton site (for some time) and when it snowed it always melted over the burial area. Might make for an interesting detective story about what happened to S1G.

  11. Paul Sicard

    I recall reading/hearing that the sodium reactor was forced on Rickover and the Navy, and that Rickover figured the only way he could kill the project, despite heavy academic support, was to build it and show how unworkable it was. Hence SEAWOLF and the subsequent quick decision to rip out the sodium plant and replaced it with a light water PWR.

  12. Neil Brown

    Steam generators (SG) have proved to be one of the more challenging components in the sodium cooled breeder reactors. The fact is that too little attention has been applied to the development of this component given the challenge and importance to the plant. DOE and its predecessors focused far more attention to the nuclear materials and fuel area. This of course is also important but the efforts has probably been over done compared to the SG. Both the Russians and Japanese have successful SG designs, perhaps not the best and most economical, and EBRII SGs, clearly not economical, operated without failure for nearly 30 years. The SGs built for Clinch River were successfully tested. GE has some designs that are likely to show considerable improvement in both cost and reliability. This component is still the one needing the most development attention.

  13. Roger N Blomquist

    It’s worth pointing out that Argonne National Laboratory’s EBR-II reactor started up in 1964 and produced steam-cycle electricity reliably for 30 years. It was obviously a different design, but it proved that liquid-metal-cooled reactors would work, and could work well.

  14. George Silvestri

    From the technical literature there was enough information to foresee that sodium, in any form, on the secondary side posed serious problems.
    In an evening course on Power Plants, when I was a senior at Drexel University, and a coop student at the Westinghouse Steam Division, Sam Arnow of PECO expressed the opinion that the best power plant was the one that runs. This affirmed the experience during the early development and use of nuclear reactors for submarine propulsion.

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