Piqua Nuclear Power Facility, Bridge Street, Piqua

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Bridge Street, 0.5 mile south of Garnsey Street and immediately north of the Piqua Waste Water Treatment Plant, City of Piqua, Miami County, Ohio The building is located at latitude: longitude: centered on the containment dome. This point was obtained on March 25, using the Ohio State Historic Preservation Office s Online Mapping System There is no restriction on its release to the public.

Source document Quoted word for word from HAER OH-144. Not written, edited or summarised by this site.

The Piqua Nuclear Power Facility was one of two demonstration reactors built in the second round of the U.S. Atomic Energy Commission s (AEC) Power Reactor Demonstration Program The first round of the was intended to stimulate the design, construction, and operation of experimental nuclear reactors for electricity generation. The second round of the was intended to construct demonstration reactors using designs that were sufficiently technically mature to test operational reliability in commercial operation. The Piqua Nuclear Power Facility was designed as an organically cooled and moderated reactor. Construction began in and the reactor went critical in with City of Piqua personnel operating the facility and generating steam for the municipal power plant.

The facility was the first nuclear power plant of any type to be operated by a municipal utility. The AEC soon concluded that organically moderated reactors would not be sufficiently competitive with light water reactors to warrant further support. The reactor was decommissioned and decontaminated between and and then the facility was leased to the City of Piqua for offices and storage.

Source document Quoted word for word from HAER OH-144. Not written, edited or summarised by this site.

This documentation was sponsored by the U.S. Department of Energy as mitigation for the demolition of the facility. Douglas Terpstra (ASC Group, Inc.) served as photographer and historian, with the assistance of Nichole Lashley and Gabby Fulton. Susan Berg (U.S. Department of Energy) and Joe Trnka (RSI Entech) provided research materials. Part I. Historical Information A. Physical History 1. Date of construction: 61 2. Architect and Builder: Atomics International, a division of North American Aviation, Inc., designed and oversaw construction of the facility. The overhead crane in the reactor dome was fabricated by the Conco Crane Company. 3. Builder: Not known 4.

Original plans and construction: The original plan of the facility includes the reactor building, characterized above ground by the steel and concrete containment dome on the west, and the support building, mostly clad in metal panels, on the east. 5. Alterations and additions: No additions were made to the building. During the decommissioning and decontamination of the facility in 69, a garage door was inserted in the west side of the containment dome to facilitate the removal of equipment. The U.S. Atomic Energy Commission (AEC) removed reactor fuel rods, coolant, and most of the radioactive materials that were in the facility, along with the tanks, boiler, coolant pumps, and fueling equipment from the reactor building.

Within the containment dome, a waterproof membrane and a layer of concrete were installed above the top of the reactor. The control console and instrument panels were removed from the control room. The hot change/cold change/locker room has been converted to a single larger room, but the date of this alteration, whether during or after decommissioning, is unclear.

During the period following when the City of Piqua leased the facility, the steel exhaust stack on the east side of the building was removed, windows in the administration room were replaced with vinyl windows, double doors in the south wall of the emergency generator and compressor room were replaced with vinyl PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 3) windows, and cosmetic changes were made on the interior, the latter including the installation of drywall over older plaster walls on the first floor of the support building. In 19, the DOE oversaw asbestos abatement, which included the removal of some pipes, floor tiles, and sinktops and countertops. Some wall sections and ceiling materials were removed to access pipes with asbestos insulation. B.

Historical Context 1. Development of civilian nuclear reactors for generating electricity 1 Prior to providing the context of developing civilian nuclear reactors, a brief overview of the scientific process seems merited. In very basic terms, nuclear reactors work by initiating the process of fission, the splitting of the nucleus of an atom into two parts, the result of which is the release of energy, mostly in the form of heat. The split also generates two or more neutrons, which then move on to strike and split other nuclei in a chain reaction. In order for a chain reaction to occur, the fissionable material must be assembled in a particular configuration of sufficient mass called the critical mass, and reactors are said to go critical or achieve criticality when that mass is obtained.

The operators of a reactor control the chain reaction by regulating the rate at which neutrons are produced. In a reactor, fission occurs in the core where the fuel elements containing the nuclear fuel are arrayed. Control rods are positioned among the fuel elements and can be inserted or withdrawn to control the level of reactivity. Coolant circulates around the fuel elements to remove the heat generated during fission. The heat is transferred out of the core and used to generate steam, which drives a turbine. In the case of electricity generation, the turbine then turns a generator. When fission occurs, the neutrons generated move at different speeds.

Reactors using natural or slightly enriched uranium for fuel cannot sustain a chain reaction unless fast- moving neutrons are slowed down using a material called a moderator. Reactors can be engineered for using different combinations of materials for fuel, coolant, and moderator. The reactors used for commercial operation today are light water reactors, which use ordinary water as coolant and moderator. However, the AEC experimented with a variety of other reactor types in the and 1 The information in this section has been adapted from Wendy Allen, Nuclear Reactors for Generating Electricity: U.S. Development from to National Science Foundation Grant No. OEP75-21596 (Santa Monica: Rand, PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 4) The science of the U.S.

atomic program, originally under the auspices of the military, was transferred to the new civilian AEC through the Atomic Energy Act of Among the responsibilities given to the AEC was to assist and foster private research and development to encourage maximum scientific progress. However, the AEC also was tasked with controlling the dissemination of information about nuclear technology, which retained its restrictive wartime classification. Private ownership of fissionable material also remained prohibited. As a result, early experimentation with nuclear power for energy production was conducted directly under the control of the AEC, although sometimes with private industry assistance, and mostly at various national laboratories and testing sites.

This situation changed in the when President Dwight Eisenhower announced his Atoms for Peace policy and Congress passed a new Atomic Energy Act Eisenhower believed that building a nuclear electricity- generating plant with no military function would demonstrate both U.S. technological superiority and U.S. intentions to develop peaceful uses of atomic energy. Research to develop a nuclear power system for aircraft carriers using a light water pressurized water reactor was converted to a civilian power reactor project after the Navy project was cancelled in The result of the research was the construction of a nuclear facility at Shippingport, Pennsylvania beginning in September in a partnership between the AEC, Westinghouse, and Duquesne Light Company.

The new Atomic Energy Act allowed private ownership of nuclear facilities and private use of, but not ownership of, nuclear materials; greater private access to information about reactor technology; a more liberal patent policy; and the supply of AEC services and materials to commercial firms. However, one remaining problem was that private industry did not consider nuclear technology to be mature enough to warrant large-scale investment in research and development and construction. Another problem, at least in the short term, was that nuclear power was not commercially attractive due to the ready availability of multiple sources of inexpensive electric power.

While the government preferred to allow private industry to carry the weight of reactor development, the AEC recognized that progress in solving the technical problems of the early prototype reactors would only occur with government financing. Thus, in January the AEC announced the first round of the Power Reactor Demonstration Program in order to stimulate private industry to finance the design, construction, and operation of experimental nuclear reactors for electricity generation. The first round of the limited AEC assistance to research and development support, and the private industry partner had to bear almost all of the financial risk PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 5) associated with building and operating the reactor and power plant.

The AEC s goal in the first round was to support projects that would advance power reactor technology, thus reducing the technical uncertainties that stood in the way of increased commercial participation. The AEC received four proposals under the first round of the The Yankee Atomic Electric Company, based in New England, proposed a although not one sharing the design of the Shippingport facility. The Nuclear Power Group, with Commonwealth Edison as a chief participant, proposed a direct cycle boiling water reactor Consumer s Public Power District proposed a sodium graphite reactor. The Power Reactor Development Company, consisting of Detroit Edison and other partners, proposed a fast breeder reactor using liquid sodium as coolant.

The two light water facilities, Yankee Atomic and Nuclear Power Group, both eventually entered successful operation. However, the Consumer s Public Power District facility in Hallam, Nebraska and the Power Reactor Development Company facility, while achieving criticality, did not prove to be successful enough for the AEC to continue their support. Despite work barely having begun on the four first round facilities, the AEC announced the second round of the in September In contrast to the first round which had focused on construction of prototype reactors that would contribute to the development of large reactors for central station electricity generation, the second round focused on construction of small experimental power reactors suitable for rural areas and foreign export.

Rural electrical cooperatives and municipalities had expressed interest in nuclear power, but could not commit the required funds and assume the financial risk that large private utilities or consortiums could. As a result, in the second round the AEC offered to finance and retain ownership of the reactor portion of the power plant in order to lower the non-AEC investment to no more than the cost of a conventional power plant. The AEC received seven proposals, each for a different reactor type, by the February deadline. Of the seven proposals, the AEC rejected three, terminated contract negotiations on two, and eventually funded two: a BWR for the Rural Cooperative Power Association (RCPA) in Elk River, Minnesota, and an organic moderated reactor in Piqua, Ohio.

While both facilities entered operation, the Elk River reactor only produced power from to when water was discovered leaking from cracks in the reactor vessel and piping, and the cost of repair or replacement was more than the RCPA or AEC was willing to assume. The Piqua facility achieved criticality in but the AEC had by that time concluded that the prospects of improving organic reactor performance to a PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 6) level competitive with light water reactors were low and decided not to continue further support of the concept. The Piqua reactor was shut down in The AEC announced a third round of the in January although this round had no deadline for proposals.

The AEC placed no limitation on the type or size of the reactors that would be considered for support, but required that the necessary research and development be of finite scope, which favored larger, commercial-scale plants. Once again, the AEC restricted their assistance to supplying nuclear materials and research and development assistance. Some of the projects in which the AEC participated in this round were successful, such as a BWR at Big Point Rock in Michigan, while others were not, including several unsuccessful attempts to build a heavy water reactor. After seven years of experience with the demonstration program, the AEC announced a modified third round of the in August This round was focused on non-experimental projects, toward proven designs (i.e.

light water reactors), and toward precise specification of contractual requirements in advance of receiving proposals. The goal was to support the construction of large base load, electrical generating facilities to demonstrate proven reactors as reliable sources of electric power. The AEC offered only approximately 10 percent of the total project cost in the form of pre-construction research and development; the participating utilities had to cover the remaining costs and to operate the facility for a period of five years after initial criticality. Under this round, Connecticut Yankee Atomic Power successfully built a PWR plant and a plans for a proposed plant in Los Angeles were discontinued when a suitable location could not be found.

Although problems continued to arise in attempts to operate nuclear electrical- generation plants in a commercially successful manner in the U.S., by the it had become clear to the AEC that light water reactors were the closest to achieving this goal among all of the varied reactor designs under experimentation in the and 2. Piqua Nuclear Power Facility An organic moderated reactor uses a terphenyl mixture as the coolant and moderator. Terphenyl is a hydrocarbon (molecule composed of hydrogen and carbon). Molten terphenyl slows the neutrons in the nuclear reaction to their most efficient speeds and then transfers heat to an exchanger where it converts water into steam.

The advantage of using a reactor of this type is that it can produce fairly high steam temperatures at comparatively low reactor pressures due to the PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 7) high boiling point of the hydrocarbon. The material also does not become highly radioactive in the reactor or cause the corrosion problems present in some other coolant types. Also, because the terphenyl does not readily absorb neutrons, it is possible to use uranium fuel with only a low level of enrichment. 2 The design for an organic moderated reactor was first tested at the Organic Moderated Reactor Experiment (OMRE) at the National Reactor Testing Station in Idaho.

Piqua s proposal for a reactor of this type was contingent upon the success of the OMRE and completion of a separate research and development program to develop reliable fuel elements. The OMRE went critical in September and operated for a year, thus demonstrating the technical feasibility of the design.3 Even after the successful operation of the OMRE, technical problems remained. Organic materials tend to decompose and replacing them would add to the operating and maintenance costs for a commercially-operating reactor. A method had to be found to remove particles of decomposed organic material that stuck to the inside of the reactor and fouled the heat transfer system. In addition, the OMRE was not designed to generate electricity and was not hooked up to a turbine.

A number of these technical uncertainties had been resolved by 4 Atomics International resolved the decomposition problem by incorporating a purification system in the heat transfer circuit and continuously adding a small amount of fluid to the system to replace the decomposed material that was removed.5 North American Aviation submitted a proposal to the City of Piqua regarding an organic moderator reactor with an output of kilowatts on January 17, The Piqua City Commission authorized the city s utilities director, John P. Gallagher, to submit a proposal to the AEC on January On February 7, the AEC announced that Piqua s proposal was one of seven received with the Atomics International division of North American Aviation as the design agent. 7 2 Joseph L.

Myler, Piqua s New Atom Plant May Hurry Day of Cheap Power, Lima Citizen (Lima, Ohio), 3 July p. 3. 3 Wendy Allen, Nuclear Reactors for Generating Electricity: U.S. Development from to National Science Foundation Grant No. OEP75-21596 (Santa Monica: Rand, 63 64. 4 Ibid. 5 Joseph R. Trnka, Historic Building Survey, Piqua, Ohio, Decommissioned Reactor Building (Grand Junction, Colorado: Navarro Research and Engineering, Inc., prepared for the U.S. Department of Energy, Office of Legacy Management, 10. 6 Dayton Daily News (Ohio), 25 January 7 Jack Vincent, AEC Eyes Designer for Plant at Piqua, Journal Herald (Dayton, Ohio), 8 February 1.

PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 8) In May the AEC announced that tests at the OMRE had concluded that the radiation hazard for the organic moderator reactor design would be minimal and construction of the Piqua facility would begin in spring The AEC was expecting a cost for development and construction of Piqua was to provide the site, conventional power-generating facilities, and operating funds for five years for a total of The site for the plant was expected to be near the city s existing power plant with the site guaranteed by a rent-free lease for 10 years, with AEC having the option of yearly renewals to a maximum of 15 years.

8 However, on August 7, AEC s advisory committee on reactor safeguards came out against the proposed site adjacent to the city s power plant on the west side of the Great Miami River. The committee felt that the site was too close to the city s center of population. The city proposed a different site on the east side of the river, which the committee approved contingent on the inclusion of a steel containment dome as part of the design in order to prevent the spread of radioactivity in case of an accident. The AEC signed contracts with the city and North American Aviation in June The schedule called for groundbreaking on July 1, plant completion in July and criticality in August This schedule was not met.

Construction was not completed until November and pre-operational testing continued into The construction site received a great deal of attention from the press in western Ohio, as well as receiving visits from scientists12 and foreign businessmen and government officials.13 Press coverage was a mix of technical explanation of how the plant works, boosterism, and reassurances of the facility s safety. Two newspapers, the Dayton Daily News14 and the Lima Citizen15, published large photo spreads of the construction. The first fuel elements were loaded into the reactor on May 25, to initiate testing with the facility at a zero power level.

16 The reactor achieved criticality on June 10, while testing continued.17 The facility first produced electricity on November 4, City personnel operated the facility, initially with representatives of Atomics International present in an advisory 8 Dick Cull, Construction on Piqua A-Plant Set Next Spring, Dayton Daily News (Ohio), 23 May 9 Myler, 1. 10 Allen, 65. 11 Helen Wilson, Reactor Loaded at Piqua Plant, Journal Herald (Dayton, Ohio), 28 May 20. 12 Hank Harvey, Preview of Century, Lima Citizen (Lima, Ohio), 20 May 13 Jack Redmond, Engineer Sees Baby Grow to Maturity at Piqua, Journal Herald (Dayton, Ohio), 25 November 16. 14 G. T. Binder, Scientists on Shores of Miami to Sell Piqua Atomic Juice , Dayton Daily News, 8 March 20. 15 Harvey, 16 Wilson, 20.

17 Jack Smith, Piqua Reactor Firing, Atomic Power in Offing, Cincinnati Enquirer, 16 June 14-A. PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 9) capacity, but full responsibility for the operation of the facility passed to Piqua on August 11, The facility produced approximately 20 percent of the city s electrical power in and The reactor was shut down for maintenance in January Problems were found with the movement of the control rods and fuel elements. The AEC publically stated that as a demonstration plant they had anticipated problems and saw no reason the problems could not be solved. 20 However, as noted above, the AEC had already decided not to continue support for the organic moderated reactor design, and the Piqua reactor was never restarted.

On December 13, the AEC terminated its contract with the City of Piqua and began the decommissioning of the reactor and the clean-up of the facility. The AEC completed their decontamination of the facility in February 21 In the AEC entered into a lease agreement with the city, where the AEC would retain ownership of the site and long-term responsibility for custody and care of the waste materials and the city would maintain the land and buildings. The city used the facility for offices, meeting rooms, and storage.22 Part II. Architectural Information A. General Statement 1.

Character: The Piqua Nuclear Power Facility consists of two distinct sections: a roughly rectangular support building of up to three stories and a round reactor building characterized above grade by its containment dome. The two sections are linked by a small one-story section of concrete construction. 2. Condition of fabric: The facility s exterior fabric is in good condition. The condition of the interior of the support building is fair, but some wall, floor, and ceiling areas or surfaces have been removed to facilitate asbestos abatement. Piping has been removed throughout the facility as part of the asbestos abatement. Fire suppression pipes in the containment dome are in poor condition.

18 Bill Fox, Piqua s Atomic Anniversary Passes with Little Fanfare, Dayton Daily News, 6 December 19 Bill Fox, Nuclear Power Old Hat to Piqua, Dayton Daily News, 10 December 37. 20 Walter Rybeck, Piqua A-Power Good and Bad, Dayton Daily News, 10 May 21. 21 Fox, 37. 22 Trnka, 2 5. PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 10) B. Description of Exterior 1. Overall dimensions: The facility has total maximum dimensions of 133 -8 x 78 -0 . The reactor building has a maximum height of 68 -0 above grade and 44 -0 below ground, the latter including a basement and sub-basement. The support building has a maximum of three stories, although not all of the building rises to this height. The support building also has a basement.

Due to grade change, the basement level is fully exposed on the facility s east side. 2. Foundations: The foundations are concrete. 3. Walls: The support building is clad in porcelain enamel steel panels on its north wall and wrapping around the east and west corners. The remainder of the above- grade walls are clad in corrugated metal siding. The north wall of the entrance vestibule and the base of the front porch formerly were clad in brick, but are not covered with exterior-grade plywood. The exposed basement on the east is concrete. The one-story air lock and electrical access room section connecting the two primary buildings of the facility is concrete. The containment dome has a steel shell over concrete. 4. Structural system: The reactor building is concrete.

The support building has a steel frame. 5. Openings a. Doorways and doors: The entrance vestibule on the north wall of the support building has glass doors. The other exterior doors are steel. A garage bay in the east wall of the basement of the support building is original, but the date of the roll-up garage door is uncertain. The garage bay in the west side of the containment dome was added during decommissioning of the facility in the late The date of its door is uncertain. b. Windows: The only windows in the entire facility are a band found along the east wall of the administration room of the support building. Existing windows are modern vinyl replacements. 6. Roof: The support building has flat built-up roof sections.

The reactor building roof is the containment dome, which consists of a steel shell over concrete. PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 11) C. Description of Interior 1. Floor plans: In the support building, the entrance vestibule opens into an administration room.23 From the administration room, corridors extend south and west. The south corridor provides access to the health physics room, the battery room, the emergency generator & compressor room, and the switchgear room, as well as both stairways leading to the upper floors. The west corridor leads to restrooms, the hot change/cold change/showers/locker room suite, the monitor laboratory and counting room, and the basement stairs.

At the west end of this corridor is the one-story concrete-walled section connecting the support building with the reactor building. The connector contains the main air lock, south of which is the electrical access room and lunch room. The latter room also connects back to the switchgear room. The south part of this section is a nitrogen storage room with only exterior access. The support building has a partial second floor, mostly on the west half of the building. Rooms on this floor are directly accessed from stairways. These rooms include a heating & ventilation equipment room and a cable spreading area. The third floor includes an even smaller area in the southwest corner of the building containing primarily the control room.

The stairways open to the northeast and southeast corners of the room. This floor also contains an instrument repair room and a restroom. One stairway descends from the ground floor of the support building into the basement. At a landing on this stairway, a doorway provides access into a storage room under the connector section. The basement level has a central passageway extending east-west, with a garage bay to the exterior at its east end. At its west end, behind a concrete blast wall, is an emergency air lock between the reactor building and the support building. North of the passageway is the stairway, the aqueous waste room, the exhaust & filter room, and the maintenance room; the latter below the aforementioned storage room.

South of the passageway is the waste-fired boiler room, the decay tank room, the purification room, and the drain tank room; the latter below the connector section. The decay tank room is only accessible via a ladder and platform in the south wall of the waste-fired boiler room. The main level of the reactor building, under the containment dome, was primarily accessed through the air lock from the support building. A concrete blast wall west of the air lock channels foot traffic to the south of the air lock. 23 Room names are derived from the original plan sheets. PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 12) North of the air lock are two rooms with a catwalk above them; these served as a contaminated storage room and an equipment decontamination room.

A new fuel rod storage room is located at the south end of the main level. The main stairway to the reactor building s basement abuts this room to its east. To the room s west is the equipment air lock. A spiral stairway to the basement levels is located at the northwest corner of the main level. An open shaft in the floor northeast of the reactor descends to the sub-basement. This shaft is not shown on the original plans. The basement level of the reactor building has a C-plan, as the concrete reactor encasement extends to the west wall of the building. The stairway opens into a large room occupying the south half of the basement, which is labeled on plans as the degasifier & shield cooling room. The west end of the emergency air lock opens into this room.

The north half of the basement is a series of gantries and walkways suspended above the sub-basement. The sub-basement has a tunnel running below the western portion of the concrete reactor encasement, allowing a full circuit around this level. The south half of the sub-basement is labeled as the drain tank room. The north half is the heat transfer room. 2. Stairways: The support building has two stairways to the upper floors and one to the basement. All are similar with steel frames and railings. The main stairway in the reactor building also is similar. The secondary stairway in the reactor building is a steel spiral stairway. 3. Flooring: The floors are concrete supported by steel beams.

Portions of the support building had floor tiles, but these were removed as part of the asbestos abatement. 4. Wall and ceiling finish: All walls and ceilings in the reactor building and the basement of the support building are concrete. In the support building, interior and some exterior walls are plaster on metal lath. Some rooms have exposed metal paneling along the exterior walls. Examples include the north wall of the administration room and the east and south walls of the emergency generator and compressor room. In some of the latter rooms, wood studs remain where later drywall was installed and then removed during asbestos abatement. Examples include the change/shower/locker room suite and the emergency generator and compressor room.

Some ceilings are also lath and plaster (administration room), while other rooms have no proper ceiling with the metal panels below the roof left exposed (battery room). Portions of the lath and plaster, in some cases entire walls, were removed to facilitate asbestos abatement. PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 13) 5. Openings a. Doorways and doors: The interior doors are metal with simple metal frames. Many doors have been removed from their hinges to facilitate asbestos abatement activities. b. Windows: The building has few windows, and there are no surviving interior window framing or finishes. 6. Mechanical equipment a.

Reactor: The reactor was a 45.5-megawatt, organically cooled and moderated thermal reactor contained within 27 -0 tall, 7 -7 diameter vessel made of low-carbon steel. The reactor vessel is entirely below ground and is encased within an 8 -0 concrete bioshield. Access to the reactor vessel in the containment door was covered with a waterproof membrane and an additional layer of concrete when the facility was decommissioned. Most associated equipment in the reactor building was removed during the facility s decommissioning, including the tanks, boiler, coolant pumps, and fueling equipment. The AEC placed three bronze plaques within the reactor building providing legacy information regarding the reactor vessel. b. Air locks: The facility has three air locks.

The primary pedestrian air lock is located in the one-story concrete connector section and links the ground floor of the support building with the containment dome floor of the reactor building. This air lock is a large steel cylinder with an opening at either end. Although it presumably once had a steel door at either end, only the door at the west end remains. This end also has a standard metal hinged door. The sides of the air lock on its interior are lined with basins and shelves. The exterior east wall of the air lock has a metal manufacturer s plaque providing the name Graver Ohio Special and serial number along with various pressure and temperature ratings.

The equipment air lock is located in the southwest corner of the containment dome and provided a pass-through for equipment or materials that could not be brought into the building through the pedestrian air lock. This air lock is also a steel cylinder. The air lock s interior door is no longer present. The interior end projects only approximately one inch from the wall. The exterior door remains in place. The exterior end of the air lock projects from the building within a concrete housing. The base and PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 14) west side of the housing project beyond the air lock to form a shelf.

A concrete slab set on the ground on the west side of the air lock could be moved into place on this shelf, which would seal off the air lock from outside access. No manufacturer s plaque was observed. The interior of the air lock was fitted with a metal floor and shelves to act as storage space during the City of Piqua s occupancy of the building following its decommissioning. The emergency air lock provides access between the basement of the reactor building and the basement of the support building. This air lock is a narrow steel cylinder. Presumably doors were located at either end, but only the door at the support building end remains in place. This door has a manufacturer s plaque for the Henry Pratt Company. This air lock projects out of the wall for a short distance at either end.

c. Overhead crane: The overhead crane spans the interior of the containment dome and is set on a ring at the top of the sides of the dome. A plaque identifies the manufacturer as Conco Crane. The crane consists of two steel beams, one of which has a walkway on its outer edge, between which the crane mechanism can run along tracks. The crane was used to lift the reactor lid for fueling or defueling and for moving the fuel rods. d. Ventilation system: Portions of the air circulation equipment are still present in various locations of the support building. Ductwork and associated equipment are still present in the heating and ventilation equipment room on the second floor.

Although labeled as a storage room on plans, an intermediate sub-level room above the basement contains a large section of ductwork. In the northeast corner of the basement is the exhaust and filter room. Some equipment remains in place in this room. e. Storage tanks: Several storage tanks for the coolant system remain in place in the basement of the support building. A cylindrical steel tank is located in the aqueous waste room in the northwest corner of the basement. This room also contains several steel gantries and ladders; one gantry holds a smaller steel tank. A steel cylindrical tank also remains in the drain tank room in the southwest corner of the basement. The decay tank is mostly encased within its room s concrete walls on the south side of the basement.

Access is only available through a steel ladder and platform in the waste-fired boiler room in the southeast corner of the basement. PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 15) f. Control room: The control room has little surviving equipment. The control console and instrument panels were removed when the facility was decommissioned, but marks on the floor clearly show their original location. The south wall still has an annunciator panel with small light-up panels labeled for various rooms throughout the facility. g. Electrical access room: Within the electrical access room in the support building, blast-proof conduits carried electrical lines through the containment dome to the reactor building. These electrical lines have all been severed.

The conduits are left exposed in the support building, but are located within steel cabinets within the reactor building. The electrical access room also contains the control box for the cathodic protection rectifier. D. Site Layout: The character of the land surrounding the facility is strictly industrial with no formal landscape design. The facility was constructed on City of Piqua property. The city s waste water treatment plant is located to the south and east. A parking lot and a material and equipment storage yard is located north of the facility. A limestone quarry is located adjacent to the city property to the north and east. Bridge Street runs on a north- south orientation west of the city property and parallel to the Great Miami River to the west of the road.

Steam generated by the facility was carried through underground pipes approximately 900 to the city s power plant on the west side of the river, crossing the river over a steel footbridge. Part III. Operations and Process A. Operations: Atomics International s design for the reactor called for 138 fuel elements and 10 control rods immersed in the coolant/moderator fluid and contained in a thin- walled core tank. The fuel elements and control rods formed a cylinder approximately 4 - 6 in diameter and 6 -6 in length. An iron reflector-thermal shield, approximately 6 thick, enclosed the core tank. The assembly was contained in the steel reactor tank. The fuel elements were suspended from the top gird plate and enclosed in steel boxes that extended through the bottom of the core tank.

The control rod drive mechanisms were located below the core with the control rod thimbles extending upward through the core into the region above the top thermal shield. The control rod thimbles were surrounded by iron sleeves above the top thermal shield to prevent radiation streaming. The coolant flowed into the top plenum between the core and the top thermal shield. It then flowed downward through the fuel elements and around the control rod thimbles into the bottom plenum. The fuel elements were individually orificed to produce a PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 16) maximum bulk outlet temperature. A portion of the coolant flowed through holes in the top grid plate to cool the steel boxes and the external areas of the fuel elements.

From the bottom plenum, the coolant flows upward through the bottom thermal shield and around the outside of the core, cooling the side thermal shield to the outlet pipe. A steel shell connected to the upper and lower grid plates at the periphery of the core separated the upward and downward coolant passes. 24 B. Technology: The use of an organic fluid in a reactor had both advantages and disadvantages. The low vapor pressure of the organic coolant enabled high temperature operation near atmospheric pressure to 300 pounds per square inch (psi) versus to psi for water cooled reactors). The lower pressure eliminated the need for heavy forgings for pressure vessels, fittings, and pipes and reduced the probability and severity of a loss of coolant accident.

The organic coolant had little corrosion potential, which enabled the use of plain carbon steel and aluminum. The low activation of coolant and corrosion products allowed for reduced biological shielding requirements. Organic coolant allowed for flexibility in the fuel used due to elimination of fuel-coolant interaction potential in the event of a cladding breach. Finally, organic fluid provided enhanced moderation allowing for use of slightly enriched uranium. Disadvantages of this technology included the thermal and radiolytic degradation of organic coolants leading to generation of volatile organic compounds and/or polymerization. This required the removal of volatile products from the organic fluid.

Polymerization could lead to increased viscosity and film formation on cladding if the core is not designed property and the coolant is not purified. This is in part what led to the shutdown of the Piqua Nuclear Power Facility. Coolant decay also necessitated the addition of make-up coolant, either through reformation of the original coolant or the introduction of fresh coolant into the system. In addition, terphenyls, the most common form of organic coolants and used at Piqua, are moderately toxic and slightly flammable, which required the use of inert cover gas and care to prevent the introduction of air into the coolant system. Finally, organic coolants have mediocre heat transfer relative to water, requiring special fuel element design to avoid high film temperatures.

At Piqua, the reactor used an annular fuel design clad in finned aluminum to improve heat transfer. Polymerization of the organic fluid resulted in the formation of high boilers, which are organic compounds with a boiling point above that of terphenyl, light organic compounds, and hydrogen. In addition, there was a risk of leakage in the heat exchanger introducing water into the organic coolant. An automatic, continuous purification unit was designed for Piqua, as was a degasifier system. As designed, the purification unit fed the hot coolant into a flash chamber maintained at a pressure of about 1 psi. Most of the 24 Information in this section is derived from Trnka, 11.

PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 17) coolant would be flash-vaporized into the coolant condenser. The remaining coolant would enter a stripping column where the last bit of coolant would be removed from the high boilers. Removal of gases was to be accomplished through the principle of a reduction in the solubility of the gases with decreasing pressure. The high boiler removed from the coolant was expected to be disposed of through combustion, but the high boiler contained radioactive particles from activated corrosion products and volatile radioactive gases. The design of the Piqua facility included a decay tank capable of holding a six- month output of high boiler, providing for decay of short-lived isotopes.

In general, pressurized organic-cooled and moderated reactors from the followed the same design principles as pressurized water reactors. The basic primary system of the organic-moderated reactor consisted of the reactor, coolant circulating pumps, steam generators and superheaters, a surge tank, and connecting piping. Side streams led to the degasifier and to high boiler and particle-removal systems. The primary system pressure was applied and controlled by the degasifier system. The secondary steam system operated at higher pressures than the primary system in order to achieve an economical steam cycle. Some of the problems leading to the shutdown and removal of the Piqua reactor were related to the use of organic fluid as coolant and moderator and others were not.

Non- coolant problems included the secondary side corrosion of the steam generator tubes due to the steam, control rod drive mechanism problems, and buckled fuel elements due to fuel handling. However, facility operators also discovered that carbonaceous material, likely formed by coolant degradation, was preventing fuel elements from seating property. Later analysis of the material revealed that the degradation was probably due to flow stagnation at certain parts of the fuel element, leading to local hot spots and coolant polymerization.25 C. Workers: Workers at the facility were employees of the City of Piqua, initially overseen by employees of Atomics International. Newspaper articles reported that some of the personnel were U.S.

Navy veterans, due to experience with nuclear reactors in naval vessels. 26 D. End Product: The end product was the production of steam. Steam generated by the facility was carried through underground pipes approximately 900 to the city s power plant on the west side of the river, crossing the river over a steel footbridge. 25 Information in this section is derived from Koroush Shirvan and Eric Forrest, Design of an Organic Simplified Nuclear Reactor, Nuclear Engineering and Technology 48 (August and C.E. Stevenson, et al., Organic Nuclear Reactors: An Evaluation of Current Development Programs (Argonne, Illinois: Argonne National Laboratory, 26 Fox, Redmond, 16. PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 18) Part IV. Sources of Information A.

Architectural drawings: The DOE, Office of Legacy Management maintains a collection of Atomic International s original plan sheets, numbering 108 in total, for the Piqua Nuclear Power Facility. B. Early views: The Piqua Public Library s Local History Department holds a small collection of historic photographs and artist s renderings of the Piqua Nuclear Power Facility. Some have been digitized and uploaded to the Ohio Memory website The Local History Department also holds a vertical file collection and some other paper items. C. Selected

Source document Quoted word for word from HAER OH-144. Not written, edited or summarised by this site.

Newspapers (all accessed through Newspapers.com): AEC Sets Piqua Reactor Meet. Dayton Daily News. 10 October p. 31. Binder, Scientists on Shores of Miami to Sell Piqua Atomic Juice . Dayton Daily News. 8 March p. 20. Cull, Dick, Jr. Construction on Piqua A-Plant Set Next Spring. Dayton Daily News. 23 May p. 1. Fox, Bill. Piqua s Atomic Anniversary Passes with Little Fanfare. Dayton Daily News. 6 December p. Fox, Bill. Nuclear Power Old Hat to Piqua. Dayton Daily News. 10 December p. 37. Further Study Set for Piqua s Atomic Plant. Marysville Journal-Tribune (Marysville, Ohio). 10 September p. 4. Harvey, Hank. Preview of Century. Lima Citizen (Lima, Ohio). 20 May p. Myler, Joseph L. Piqua s New Atom Plant May Hurry Day of Cheap Power. Lima Citizen (Lima, Ohio). 3 July p. 3.

PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 19) Piqua to Petition AEC for Pilot A-Power Plant. Dayton Daily News. 25 January p. 1. Redmond, Jack. Engineer Sees Baby Grow to Maturity at Piqua. Journal Herald (Dayton, Ohio). 25 November p. 16. Rybeck, Walter. Piqua A-Power Good and Bad. Dayton Daily News. 10 May p. 21. Schroeder, Donald. Reactor Explosion Is Impossible at Piqua Plant. Journal Herald (Dayton, Ohio). 14 January p. 3. Smith, Jack. Piqua Reactor Firing, Atomic Power in Offing. Cincinnati Enquirer. 16 June p. 14-A. Vincent, Jack. AEC Eyes Designer for Plant at Piqua. Journal Herald (Dayton, Ohio). 8 February p. 1. Wilson, Helen. Reactor Loaded at Piqua Plant. Journal Herald (Dayton, Ohio). 28 May p. 20. Wilson, Steve.

Giant Warehouse: Nuclear Facility Now a Shell. Chillicothe Gazette (Chillicothe, Ohio). 15 July p. 17. Reports and Research Papers Allen, Wendy. Nuclear Reactors for Generating Electricity: U.S. Development from to Santa Monica, California: Rand, Prepared with the support of National Science Foundation Grant No. OEP75-21596. Obtained from Shirvan, Koroush, and Eric Forrest. Design of an Organic Simplified Nuclear Reactor. Nuclear Engineering and Technology 48 (August Stevenson, C.E., J.E. Draley, Fromm, Sheffield Gordon, Iskenderian, A.A. Jonke, and Rohde. Organic Nuclear Reactors: An Evaluation of Current Development Programs. Argonne, Illinois: Argonne National Laboratory, Trnka, Joseph R. Historic Building Survey, Piqua, Ohio Decommissioned Reactor Building.

Grand Junction, Colorado: Navarro Research and Engineering, Inc., prepared for the U.S. Department of Energy, Office of Legacy Management, Obtained from author. PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 20) D. Likely sources not yet investigated: Several regional newspapers, including the Dayton Daily News, Cincinnati Enquirer, Lima Citizen, and Dayton Journal Herald, sent reporters to the facility during its construction or active operation. Some of these newspaper articles include photographs of or within the facility.

The current status of the photo archives of these newspapers was not researched for this documentation, but the Dayton Daily News and Cincinnati Enquirer at least are still active newspapers and may retain original copies of these photographs or other unused photographs. E. Supplemental Information 1. Reduced copies of a sample original plan sheets PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 21) REDUCED COPIES OF A

Sample of Original Plan Sheets

Sheet Sub-basement and basement floor plan27 27 Atomics International, Sub-Basement & Basement Floor Plan Piqua Nuclear Power Facility, Piqua Facility Site Drawings, U.S. Department of Energy, Office of Legacy Management. This image is in the public domain. PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 22) REDUCED COPIES OF A SAMPLE OF ORIGINAL PLAN SHEETS Sheet first & second floor plans28 28 Atomics International, First & Second Floor Plans Piqua Nuclear Power Facility, Piqua Facility Site Drawings, U.S. Department of Energy, Office of Legacy Management. This image is in the public domain.

PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 23) REDUCED COPIES OF A SAMPLE OF ORIGINAL PLAN SHEETS Sheet third floor & roof plans29 29 Atomics International, Third Floor & Roof Plans Piqua Nuclear Power Facility, Piqua Facility Site Drawings, U.S. Department of Energy, Office of Legacy Management. This image is in the public domain. PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 24) REDUCED COPIES OF A SAMPLE OF ORIGINAL PLAN SHEETS Sheet north & south elevations & entry details30 30 Atomics International, North & South Elevations & Entry Details Piqua Nuclear Power Facility, Piqua Facility Site Drawings, U.S. Department of Energy, Office of Legacy Management. This image is in the public domain.

PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 25) REDUCED COPIES OF A SAMPLE OF ORIGINAL PLAN SHEETS Sheet east & west elevations31 31 Atomics International, East & West Elevations Piqua Nuclear Power Facility, Piqua Facility Site Drawings, U.S. Department of Energy, Office of Legacy Management. This image is in the public domain. PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 26) REDUCED COPIES OF A SAMPLE OF ORIGINAL PLAN SHEETS Sheet building sections32 32 Atomics International, Building Sections Piqua Nuclear Power Facility, Piqua Facility Site Drawings, U.S. Department of Energy, Office of Legacy Management. This image is in the public domain.

PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 27) REDUCED COPIES OF A SAMPLE OF ORIGINAL PLAN SHEETS Sheet containment vessel-reactor building33 33 Atomics International, Containment Vessel-Reactor Building Piqua Nuclear Power Facility, Piqua Facility Site Drawings, U.S. Department of Energy, Office of Legacy Management. This image is in the public domain. PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 28) REDUCED COPIES OF A SAMPLE OF ORIGINAL PLAN SHEETS Sheet auxiliary building-elevations & sections34 34 Atomics International, Auxiliary Building-Elevations & Sections Piqua Nuclear Power Facility, Piqua Facility Site Drawings, U.S. Department of Energy, Office of Legacy Management. This image is in the public domain.

PIQUA NUCLEAR POWER FACILITY (Decommissioned Reactor Site) HAER OH-144 (Page 29) REDUCED COPIES OF A SAMPLE OF ORIGINAL PLAN SHEETS Sheet reactor building cross sections35 35 Atomics International, Reactor Building Cross Sections Piqua Nuclear Power Facility, Piqua Facility Site Drawings, U.S. Department of Energy, Office of Legacy Management. This image is in the public domain.