Atomic aviation: into the future from the past

The experience gained in 50-70-E years of the twentieth century, still useful in the XXI century

Probably, it may seem strange that nuclear energy, firmly rooted on the earth, in the hydrosphere and even in space, did not take root in the air. This is the case when the apparent safety concerns (though not only them) outweighed the obvious technical and operational benefits of introducing nuclear power plants (NMS) into aviation.

Meanwhile, the likelihood of severe consequences of incidents with such aircraft, provided they are perfect, can hardly be considered as higher in comparison with space systems using nuclear power plants (NPI). And for the sake of objectivity, it is worth recalling that the accident of the US-A satellite of the Cosmos-1978 type satellite US-A with the fall of its fragments into the territory of Canada did not lead to the collapse of the naval space intelligence system and targeting (MKRTS) "Legend", the element of which was the US-A devices (5F954-K).

On the other hand, the operating conditions of the aviation YASU, designed to create thrust by generating heat in a nuclear reactor, supplied to the air in a gas turbine engine, are completely different than satellite NPIs, which are thermoelectric generators. Today, two principal schemes of aviation YSU are proposed - open and closed. The open type scheme provides for heating the air compressed by the compressor directly in the reactor channels with its subsequent outflow through the jet nozzle, and the closed type - heating the air with the help of a heat exchanger, in a closed circuit of which coolant circulates. A closed circuit can be single- or dual-circuit, and from the point of view of ensuring operational safety, the second option looks most preferable, since the reactor unit with the first circuit can be placed in a protective anti-shock shell, the tightness of which prevents catastrophic consequences in case of aircraft accidents.

Water-cooled and fast neutron reactors can be used in closed-type aviation control systems. When implementing a two-circuit scheme with a “fast” reactor in the primary circuit of YASU, both liquid alkali metals (sodium, lithium) and inert gas (helium) would be used as a coolant, and in the second - alkali metals (liquid sodium, eutectic sodium melt and potassium).

IN AIR - REACTOR

The idea of ​​using nuclear energy in aviation was advanced by Enrico Fermi, one of the leaders of the Manhattan project, in 1942. She became interested in US Air Force Command, and in 1946, the Americans launched the NEPA (Nuclear Energy for Aircraft Propulsion of Aircraft) project, designed to determine the possibility of creating a bomber and reconnaissance aircraft with unlimited range.

First of all, it was necessary to conduct research related to the crew’s anti-radiation protection and ground service personnel, and to give a probabilistic-situational assessment of possible accidents. In order to force the work, the NEPA project in 1951 was expanded by the United States Air Force to the ANP target program (Aircraft Nuclear Propulsion). Within its framework, General Electric developed the open, and Pratt-Whitney developed the closed scheme of YSU.

For testing the future of an aviation nuclear reactor (exclusively in the mode of physical launches) and biological protection, a serial heavy strategic bomber of the Konver company B-36H Peacemaker (“Peacemaker”) with six piston and four turbojet engines was intended. It was not a nuclear aircraft, but was just a flying laboratory, where the reactor was to be tested, but received the designation NB-36H - Nuclear Bomber (“Atomic Bomber”). The cockpit was turned into a lead and rubber capsule with an extra screen of steel and lead. To protect against neutron radiation, special water-filled panels were inserted into the fuselage.

The prototype ARE aviation reactor (Aircraft Reactor Experiment), created at 1954 by the Oak Ridge National Laboratory, became the world's first homogeneous 2,5 MW nuclear reactor powered by molten salt, sodium fluoride and zirconium and uranium tetrafluorides.

The advantage of this type of reactor lies in the impossibility of an accident with the destruction of the core, and the fuel salt mixture itself, in the case of the implementation of a closed-type aviation system, would perform the role of primary coolant. When using molten salt as a coolant, the heat capacity of a molten salt in comparison with, for example, liquid sodium makes it possible to use small circulation pumps and benefit from a reduction in metal consumption of the reactor plant structure as a whole, and the low thermal conductivity should ensure the stability of the atomic aircraft engine to sudden temperature changes in the first circuit.

On the basis of the ARE reactor, the Americans developed the Experimental Aviation Aircraft Control System HTRE (Heat Transfer Reactor Experiment). Without further ado, General Dinamix designed the X-39 aviation nuclear engine based on the J47 serial turbojet engine for the B-36 and B-47 bomber "Stratojet" - instead of the combustion chamber, it placed the active zone of the reactor.

The Convair firm had intended to supply the X-39 X-6 with the X-58 Hustler (Shustril) supersonic strategic bomber, which made its first flight in the 1956 year. In addition, the atomic version of an experienced subsonic bomber of the same company YB-60 was also considered. However, the Americans abandoned the open-source aviation system YASU, having considered: the erosion of the walls of the air channels of the X-39 reactor core would lead to the aircraft leaving behind a radioactive trace, polluting the environment.

The promise of success was promised by a more radiation-safe YASU of a closed type of the Pratt-Whitney company, to the creation of which General Dynamics also joined. Under these engines, Konver began designing the experimental NX-2 aircraft. Both turbojet and turboprop versions of nuclear bomber with YASU of this type were worked out.

However, the adoption of the Atlas intercontinental ballistic missiles, capable of hitting targets in the USSR from the continental US, in 1959, leveled the ANP program, especially since production samples of atomic planes would hardly have appeared before 1970. As a result, in March 1961, all work in this area in the United States was terminated by the personal decision of President John F. Kennedy and the real atomic plane was never built.

The flight model of an ASTR aviation reactor (Aircraft Shield Test Reactor - a reactor for testing aircraft protection systems), located in the bomb compartment of the flying laboratory NB-36H, was in no way connected with engines 1 MW fast neutron reactor, which operated on uranium dioxide and cooled by a stream of air drawn through special air intakes. From September 1955 to March 1957 of the year NB-36H made 47 flights with ASTR over the deserted regions of the states of New Mexico and Texas, after which the car was never raised to the sky.

It should be noted that the United States Air Force was also engaged in the problem of a nuclear engine for cruise missiles, or, as they used to say before the 60s, of projectile aircraft. As part of the Pluto project, the Livermore Laboratory created two samples of the Tory nuclear ramjet engine, which was planned to be installed on the SLAM supersonic cruise missile. The principle of “atomic heating” of air passing through the reactor core was the same here as in open-type nuclear gas turbine engines, with one difference: there is no compressor and turbine in a once-through engine. The Tories, successfully tested on the ground in 1961-1964, are the first and so far the only real-life aviation (more precisely, rocket-aviation) YSU. But this project was also closed as unpromising amid successes in the development of ballistic missiles.

Catch and overtake!

Of course, the idea of ​​using nuclear energy in aviation, regardless of the Americans, also developed in the USSR. Actually, in the West, it was not without reason that they suspected that such work was being carried out in the Soviet Union, but with the first public disclosure of the fact of it, they got into a mess. 1 December, Aviation Week magazine, 1958, reported: The USSR is creating a strategic bomber with nuclear engines, which caused a lot of excitement in America and even contributed to maintaining interest in the ANP program, which has begun to fade. However, in the accompanying drawings, the editorial artist quite accurately depicted the M-50 aircraft of the experimental design bureau V. M. Myasishchev, which was actually being developed at that time of a completely “futuristic” type, which had conventional turbojet engines. It is not known, by the way, whether the KGB of the USSR followed this publication: the work on the M-50 was conducted in the strictest secrecy, the bomber made the first flight later in the Western press, in October 1959, and the car was presented to the general public only in July 1961 on the air show in Tushino.

As for the Soviet press, for the first time the magazine “Technique for Youth” told in a very general way about the 8 number for 1955 year: “Atomic energy is increasingly used in industry, energy, agriculture and medicine. But the time is not far off when it will be applied in aviation. From the airfields giant cars will easily rise into the air. Nuclear planes will be able to fly for almost any length of time, for months without sinking to the ground, making dozens of non-stop round-the-world flights at supersonic speeds. ” The magazine, hinting at the military purpose of the vehicle (there is no need for civilian aircraft to “be in the sky for an“ arbitrarily long time ”), nevertheless presented a hypothetical scheme of an open-type cargo-passenger airliner.

However, the Myasishchev team, and he was not alone, really engaged in aircraft with nuclear power plants. Although Soviet physicists studied the possibility of their creation since the end of the 40-s, practical work on this area in the Soviet Union started much later than in the USA, and they were initiated by the Decree of the USSR Council of Ministers No. 1561-868 of August 12 of the year. According to him, V. M. Myasishchev and A. N. Tupolev with OKB-1955, and A. N. Tupolev as well as A. M. Lyulka and A. N. Lyulka and OKB-23 aircraft bombs. ND Kuznetsova was assigned the task of developing atomic strategic bombers.

The design of an aviation nuclear reactor was carried out under the direction of Academicians I. V. Kurchatov and A. P. Aleksandrov. The goal was the same as that of the Americans: to get a car that, having flown up from the territory of the country, would be able to strike at objects anywhere in the world (first of all, of course, in the USA).

A feature of the Soviet atomic aviation program was that it continued even when the United States was already firmly forgotten about this topic.

When creating YSU carefully analyzed the concepts of open and closed type. Thus, under the open type scheme, which received the cipher "B", Lyulka Design Bureau developed two types of atomic-turbojet engines - axial, with the turbo-compressor shaft passing through the ring reactor, and "rocker arms" - with the shaft outside the reactor located in the curved flow part. In turn, the Kuznetsov Design Bureau worked on the engines according to the closed scheme "A".

The OKB Myasishchev immediately set about solving the most seemingly difficult task - to design atomic ultrafast heavy bombers. Even today, looking at the schemes of future cars, made at the end of 50-s, you can definitely see the features of the technical aesthetics of the XXI century! These are the projects of the 60, 60М (atomic seaplane), 62 aircraft under the B-1 Lulkovsky engines, and also 30 aircraft - already under the Kuznetsov engines. The expected characteristics of the 30 bomber are impressive: maximum speed - 3600 km / h, cruising - 3000 km / h.

However, the detailed design of the Myasishchevsky atomic planes did not come as a result of the liquidation of OKB-23 in an independent capacity and its introduction into the rocket-space OKB-52 VN Chelomey.

The Tupolev team at the first stage of participation in the program was to create a similarly designated American NB-36H flying laboratory with a reactor on board. Received the designation Tu-95LAL, it was built on the basis of a serial turboprop heavy strategic bomber Tu-95M. Our reactor, like the American one, did not mate with the engines of an aircraft carrier. The principal difference between the Soviet aircraft reactor and the American one was that it was water-cooled, with much less power (100 kW).

The domestic reactor was cooled with water of the first circuit, which in turn gave off heat to the water of the second circuit, cooled by the air flow running through the air intake. Thus, the circuit diagram of the NK-14A Kuznetsov atomic-turboprop engine was worked out.

The flying atomic laboratory of the Tu-95LAL in 1961-1962 36 once lifted the reactor into the air both in the operating and in the “cold” state in order to investigate the effectiveness of the biological protection system and the effect of radiation on the aircraft systems. According to the test results, P. V. Dementiev, Chairman of the State Committee on Aviation Engineering, however, noted in his note to the country's leadership in February 1962: “Currently, there are no necessary conditions for the construction of aircraft and missiles with atomic engines (375 cruise missile with YASU was developed in OKB-301 S. A. Lavochkin. - K. Ch.), since the research work carried out is not sufficient to develop prototypes of military equipment, these works should be continued. "

Following the development of the design basis of the Tupolev design bureau at OKB-156, based on the Tu-95 bomber, a Tu-119 experimental aircraft with an NK-14 atomic-turboprop engine was developed by the Tu-119 bomber. Since the task of creating an ultra-long bomber with the appearance of intercontinental ballistic missiles and sea-based ballistic missiles (on submarines) in the USSR had lost its critical relevance, Tupolevans viewed the Tu-114 as a transitional model towards the creation of an anti-aircraft anti-submarine aircraft based on a long-range passenger airliner Tu-95 , which also "grew" from the Tu-60. This goal was fully in line with the concerns of the Soviet leadership about the deployment of an underwater nuclear missile system with Polaris ICBMs and then Poseidon by the Americans in the XNUMXs.

However, the project of such an aircraft was not implemented. Stayed at the design stage and plans to create a family of Tupolev supersonic bomber with YSU under the code name Tu-120, which, like the atomic submarine air hunter, was planned to be tested in 70-s ...

Nevertheless, the idea to give naval aviation anti-submarine aircraft with unlimited range to fight NATO atomic submarines in any region of the World Ocean in the Kremlin relished. Moreover, this car was supposed to carry as much as possible ammunition antisubmarine weapons - rockets, torpedoes, depth charges (including nuclear ones) and radio-hydroacoustic buoys. That is why the choice fell on the An-22 Antey heavy military transport with a payload of 60 tons — the world's largest turboprop wide-body airliner. The future An-22PLO aircraft was planned to be equipped with four nuclear-turboprop engines NK-14А instead of the standard NK-12MA.

Program to create such an unprecedented in none navy the winged car received the code name "Stork", and the reactor for the NK-14A was developed under the guidance of Academician A.P. Aleksandrov. In 1972, tests began on the reactor aboard the flying laboratory An-22 (23 flights in total), and it was concluded that it was safe in normal operation. And in the event of a serious accident, it was envisaged to separate the reactor block and the primary circuit from the falling aircraft with a soft landing by parachute.

In general, the aviation reactor "Stork" has become the most advanced achievement of atomic science and technology in its field of application.

If we consider that on the basis of the An-22 aircraft it was also planned to create an intercontinental strategic aviation and missile complex An-22Р with the submarine ballistic missile P-27, then it is clear what powerful potential such a carrier could receive "With engines NK-14A! And although the matter did not come to the realization of both the An-22PLO project and the An-22Р project, it must be stated that our country nevertheless overtook the United States in the field of the development of the aviation YSU.

Is it any doubt that this experience, despite its exoticism, is still able to come in handy, but at a higher quality level of implementation?

The development of unmanned ultra-long-range reconnaissance-impact aviation systems may well go along the path of the use of YASU on them - such assumptions are already being made abroad.

Scientists also predicted that by the end of this century, millions of passengers are likely to be transported by atomic passenger planes. In addition to the obvious economic benefits associated with the replacement of jet fuel with nuclear fuel, we are talking about a sharp decrease in the contribution of aviation, which, with the transition to YSU, will cease to “enrich” the atmosphere with carbon dioxide, into the global greenhouse effect.

In the author's opinion, the aviation YASU would fit perfectly into the future commercial aviation transport complexes based on super heavy cargo aircraft: for example, the same giant “air ferry” M-90 with a payload capacity of 400 tons proposed by the designers of the experimental machine-building plant named after VM Myasischev.

Of course, there are problems in terms of changing public opinion in favor of atomic civil aviation. Serious issues remain to be resolved to ensure its nuclear and antiterrorist security (by the way, experts mention a domestic decision with a parachute "shooting" the reactor in the event of an emergency). But the road, beaten more than half a century ago, will be mastered by walking.