On the same day as the keel for the nuclear-powered cruiser Long Beach was being laid, another historic event took place in a small town in Pennsylvania. During the early hours of 2 December 1957 – exactly fifteen years after Fermi had achieved the first self-sustaining nuclear chain reaction – the Shippingport nuclear power plant achieved criticality.

The man responsible for the design and construction of Shippingport was Rear Admiral Hyman G Rickover.

The Long Beach and Shippingport PWR reactors were based on technology developed in the naval nuclear propulsion programme, a joint venture of the navy and the Atomic Energy Commission (AEC). Responsible for the programme, and unquestionably the leading force behind it, was Admiral Rickover.

Birth of the PWR

The first major landmark for the naval nuclear propulsion programme occurred on 31 May 1953, the date that the land prototype for the first nuclear submarine, the Nautilus, produced power. It was this success that eventually led to Rickover being assigned the job of building the world’s first full-scale central station nuclear power plant. Several people were against Rickover being given the job, some on political grounds and some on engineering ones.

The main argument against the PWR approach was that, though this technology worked well for naval propulsion, it was too wasteful of U-235. At that time there was a shortage of uranium with defence consuming almost all of it, leaving little for civilian plants. It was also suggested that the generating capacity of PWRs was not economically significant.

However the main concern was Rickover himself: everyone knew that he would dominate the project as he did with naval propulsion, and once in he could not be removed. As was often the case during his career of almost 64 years, Rickover knew the people who could help him get what he wanted, and in this instance it was the support of commissioner Thomas Murray at the White House and in the AEC that proved to be the deciding factor.

It was about this time that president Eisenhower stated that the US should look towards peaceful uses of nuclear technology. Consequently the programme to develop a reactor for use on a large surface ship was put on hold. Rickover reassigned his staff for the proposed aircraft carrier plant to the Shippingport project. Just over a year later, after Russia detonated its first hydrogen bomb, Eisenhower reinstated the large ship reactor programme.

Shippingport project

The history of Shippingport is dominated by three organisations. First there was Rickover and Naval Reactors, the department at the heart of the naval nuclear propulsion programme. Secondly there was the Bettis laboratory, operated by Westinghouse Electric Corporation, which was to design, fabricate, test, and assemble the reactor and its heat-transfer system. And finally there was a privately owned utility, the Duquesne Light Company, which would buy the steam produced by the reactor.

Russia and England had large reactors to produce plutonium for weapons, some of these reactors produced electricity as a by-product. But no one had tried to build a nuclear plant for producing electricity on a reliable commercial basis. Rickover is therefore credited with demonstrating the feasibility of using PWR technology for civilian application. His other main achievements at Shippingport were to demonstrate how PWRs could be converted to breeding, and his application of strict discipline over the operation of the civilian reactors.

Indeed the safety culture of today’s plants can be traced back to Rickover. Back in 1947, when he went to Oak Ridge to learn about nuclear technology, Rickover understood that there were new and unusual hazards in the use of nuclear energy. He realised that, even if a minor accident were to occur, the penalty would be high – for him it would be the end of his career. At that time many scientists working in the field did not understand the safety issues in the way that Rickover did. Safety dominated his thinking.

Shippingport received the attention to detail and uncompromising attitude towards safety that Rickover exercised in the naval propulsion programme. All components came under close scrutiny and instruments to monitor every aspect of the plant were installed. Rickover also insisted on several barriers between the fuel and environment. The fuel was encapsulated in a corrosion-resistant blanket of zirconium alloy; the primary reactor coolant system was seal-welded behind the pressure-containing reactor walls; the reactor container was surrounded by a concrete wall; the steam system was housed in a series of interconnected containers; and finally the reactor plant was underground.

Another innovative feature of Shippingport was the “seed blanket” core designed by Alvin Radkowsky, chief physicist of Naval Reactors. The highly enriched U-235 seed was surrounded by a U-238 blanket. This design was intended to make considerable use of the abundant U-238. However, though the technology developed for the Nautilus gave assurance for the seed elements, it was the blanket elements that presented Rickover with one of the project’s toughest decisions. The blanket elements would need to maintain integrity in hot water and intense radiation over long periods. Bettis was working on various uranium alloys as well as uranium dioxide for use in the blanket assemblies, but needed to carry out further research. A delay at that point would have put the project at risk so a decision had to be made. Rickover’s decision – that the seed blanket be made from uranium dioxide contained in zirconium alloy tubing – had far-reaching consequences. The resulting fuel was so successful that it became widely adopted by the civilian power industry.

Power struggles

As Shippingport neared completion the AEC argued that the reactor’s operating stability had not been fully tested. Duquesne chairman and chief executive Philip Fleger was incensed and refused to depart from the contract.

Rickover pointed out to the commissioners and to Kenneth Davis, director of the division of reactor development, that it was standard procedure for the designer of any complicated equipment to be responsible for the initial testing. His argument was reinforced by the recent Windscale 1 accident, which had been partially attributed to errors of judgment by the operators. Eventually Duquesne agreed to having a technically trained and properly qualified man on watch for the length of the contract, which lasted 25 years. Rickover believed that having an independent engineer, who came to be known as the “NR Rep”, in the control room with the power to shut it down helped to ensure the plant’s safe operation.

Although successful from a technological point of view, it was unclear whether Shippingport had furthered the nuclear power industry from an economic perspective. Rickover had always refused to budge on his standards. He felt that it was up to industry to meet the elaborate and expensive techniques used for naval reactors, rather than cut corners. Once again, Rickover’s legacy carries on into the present day, but the added financial burden of his approach raised questions about the commercial future of nuclear power.

The AEC had always backed Rickover on naval propulsion but was less enthusiastic about military involvement with civilian power, something they regarded as their field. When chairman Lewis Strauss and commissioner Thomas Murray left the AEC, the new chairman, John McCone, set up a committee headed by director of reactor development Frank Pittman to study the causes of industrial reluctance and to propose a course for nuclear power development.

Rickover kept a close eye on the proceedings, managing to get two of his allies put on the committee. Pittman presented the preliminary results in April 1961, which showed that high financial risks in construction, site selection and lack of data were the main problems. Although there was no recommendation to close Shippingport, the committee believed that the government should build another plant. The reactor would have to be far bigger than Shippingport’s 60MWe in order to be economically viable.

Rickover saw this as his chance to remain a part of the civilian nuclear programme and got the Bettis laboratory to look into several designs of up to 750MWe. They were also to look into other fuel designs as the seed-blanket design did not make economic sense to an industry no longer faced with a shortage of uranium.

There was enough opposition to Rickover within the AEC and the division of reactor development to make sure that the large power reactor project stayed out of his hands. This project ended up as a joint venture between the commission and the Connecticut Yankee Atomic Power Plant for a 580MWe PWR plant. However, Congress asked Rickover to carry out an in-depth study into seed-blanket design. A plant would only be built if the results of the study showed that it would be a major technological advance.

Gradually opposition to a seed-blanket reactor increased, leaving Rickover having to find an alternative. A promising option came from the state of California, which commissioned a 500MW seed blanket reactor early in 1964. Almost two years later, with the project too far behind schedule, Rickover had to admit that he needed more time, something the state did not have. Instead Rickover focused his attentions on a programme to demonstrate breeder technology at Shippingport, which began at the end of 1965.

On the morning of 2 December 1977 Rickover was in the White House in the presence of president Jimmy Carter. Taking place exactly 20 years after Shippingport reached criticality, this occasion marked the beginning of operation of Shippingport with its light-water breeder core. This new technology not only demonstrated the feasibility of a light-water breeder reactor, but that an existing PWR reactor could be adapted to function as a breeder reactor.

Rickover and Naval Reactors were only involved in the one civilian power plant, but the contribution of the technology developed for Shippingport to the nuclear industry is immense. He may be remembered as the “father of the nuclear navy” but Admiral Rickover was also the father of the civilian nuclear power industry.