Anniversary at Obninsk: The First Commercial Nuclear Power Plant

There were numerous other prior claims made by competitors who wished bragging rights. However, none of the earlier claims involved a plant with neither parallel military nuclear fuel production capability nor which had more than a very limited ability to provide energy to a grid on a commercial basis.

In 1949, the two adversaries of the Cold War embarked seriously on programs that would lead to early examples of nuclear power plants. Speaking generally, in the United States, moves were made in the late 1940s to develop nuclear power for Naval ships and submarines. In 1949, the Atomic Energy Commission bought the giant former Naval testing ground in Idaho that would become the National Reactor Testing Station, today called Idaho National Laboratory. This would see the operation of a submarine nuclear plant in 1953.

In the USSR, however, 1949 saw the "go ahead" to engineer and construct an experimental design of a nuclear power station that would not propel a vessel, but instead would provide all its useful output as electric power for distribution to commercial customers. The design chosen was a "pile" type reactor-based more on the majority of early reactors than was the US Naval program, but which was also easier to construct and a lower cost to build.

Construction of this prototype reactor, originally referred to as APS-1 but later known as AM-1, was planned at the site of the Physics and Power Engineering Institute (PEI), which designed it and was responsible for it. The PEI was located in Obninsk, about 60 miles from Moscow. The power of the reactor had to be limited to 5 MWe in order to use a commercial turbine generator of that size that was already available. Some characteristics of the plant were as follows:

• Thermal power: 30 MWt
• Fuel loading: 1213 lbs. of 5-percent enriched U-235 in a channel design
• Coolant: Light water; core inlet 374F, core outlet 536F - pressurized to 1465 psi.
• Steam conditions: Superheated steam at 518F and 176 psi.*

The Obninsk plant was the first of a long line of channel-type Soviet reactors with graphite moderator that became known later as the RBMK series. Eventually these reactors were in wide use, in far larger sizes, around the entire Soviet Union.

The construction of the plant was remarkably rapid given the newness of the venture. The year 1951 saw the start of actual site construction and the plant was ready to load fuel by May 1954. First criticality took place on May 9, 1954, and the plant delivered nuclear-produced steam to its turbine generator on June 26, 1954. The next day, June 27, the plant was connected to the grid for the first time-a milestone in the history of nuclear energy.

Incredibly, this plant, which took on a role as a research and development facility much more than as a commercial power producer, operated for almost 50 years. Its final shutdown was on April 29, 2002. During its years of operation, PEI obtained the necessary experience in online refueling (a hallmark of Soviet design channel-type pile reactors) and in design and development of the then-new fuel elements. These fuel elements were introduced in the design, but needed to be proven worthy before being employed in the later massive buildup. Operation of the plant was safe, with only a couple of notable instances of minor fuel clad damage that was detected immediately and rectified.

The impact of this plant's initial success cannot be underestimated. By 1956, the Twentieth Party Congress of the Soviet Union declared that prior to 1960 it would build  2000 to 2500 megawatts worth of nuclear generating capacity in the USSR (a figure later retreated from, but later vastly exceeded). The plant's success led directly to the wide employment of ever-larger channel-type reactors** with graphite moderators, although the USSR did test other types.Ultimately they made the decision to drive forward doubly using the RBMK type pioneered by Obninsk and the VVER or "Water-Water Energy Reactor," better known today as the pressurized water reactor as the second choice. (Early tests with boiling water reactors were abandoned in favor of RBMK and VVER types, which the Soviets found much closer to full technological maturity; breeders were developed but not given the urgent priority that the other two types received.)

It is amazing to think of a nuclear plant project today that could be approved, designed, built, and on the grid in five years. Both the USSR and the United States were able to achieve short times like this with early (and small) plants, "in those days." The small size, however, doesn't shrink the import of the principles required to design these plants and operate them in the days when slide rules dominated engineering calculations. It is important to understand and appreciate the incredible achievements made in those heady days, now gone.

*  The low steam pressure is notable.

** The channel type or RBMK design was next employed at the Siberian nuclear power plant (actually not properly in Siberia but rather in Troitsk), which went into operation in 1958 and was not direct cycle but indirect cycle boiling water. The Siberian NPP (a militarily classified project) eventually employed six such 100 MWe reactors, placed into service through 1963. The next design was that of the first Beloyarsk unit (285 MWt, 100 MWe with integral nuclear superheat and two-pass direct cycle operation). The second Beloyarsk unit developed directly in line from the Obninsk plant through Beloyarsk-1 went on the grid in October 1967, and was rated 530 MWt and 200 MWe. This was the first Soviet nuclear plant (Beloyarsk-2, that is) to employ two turbine generators per reactor-a feature that would become a hallmark of the vast majority of RBMK-1000 and VVER-440 nuclear plants built in the succeeding years.

Sources:

•"Soviet Nuclear Power Plants - Reactor Types, Water and Chemical Control Systems, Turbines."  David Katsman.  Delphic Associates Incorporated, Falls Church, Virginia, 1986.

•"The Atomic Energy Deskbook."  John F. Hogerton.  Reinhold Publishing Corporation, New York, 1963.

•"60th Anniversary of First Russian NPP."  ROSATOM website; link here.

Will Davis is Communications Director, historian, newsletter editor 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 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. He is a former US Navy reactor operator, qualified on S8G and S5W plants.