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152-424: The Treaty on the Non-Proliferation of Nuclear Weapons , commonly known as the Non-Proliferation Treaty or NPT , is an international treaty whose objective is to prevent the spread of nuclear weapons and weapons technology, to promote cooperation in the peaceful uses of nuclear energy , and to further the goal of achieving nuclear disarmament and general and complete disarmament. Between 1965 and 1968,
304-479: A nuclear proliferation risk as they can be configured to produce plutonium , as well as tritium gas used in boosted fission weapons . Reactor spent fuel can be reprocessed to yield up to 25% more nuclear fuel, which can be used in reactors again. Reprocessing can also significantly reduce the volume of nuclear waste, and has been practiced in Europe, Russia, India and Japan. Due to concerns of proliferation risks,
456-463: A nuclear umbrella ) has been a factor limiting incentives for some NNWS to acquire nuclear weapons. Under Article VI of the NPT, all Parties undertake to pursue good-faith negotiations on effective measures relating to cessation of the nuclear arms race, to nuclear disarmament, and to general and complete disarmament. Article VI of the NPT represents the only binding commitment in a multilateral treaty to
608-436: A preemptory norm ( jus cogens ) , such as permitting a war of aggression or crimes against humanity. A treaty is an official, express written agreement that states use to legally bind themselves. It is also the objective outcome of a ceremonial occasion that acknowledges the parties and their defined relationships. There is no prerequisite of academic accreditation or cross-professional contextual knowledge required to publish
760-558: A " neutron howitzer ") produced a barium residue, which they reasoned was created by fission of the uranium nuclei. In their second publication on nuclear fission in February 1939, Hahn and Strassmann predicted the existence and liberation of additional neutrons during the fission process, opening the possibility of a nuclear chain reaction . Subsequent studies in early 1939 (one of them by Szilárd and Fermi), revealed that several neutrons were indeed released during fission, making available
912-407: A "manifest violation" is required such that it would be "objectively evident to any State dealing with the matter". A strong presumption exists internationally that a head of state has acted within his proper authority. It seems that no treaty has ever actually been invalidated on this provision. Consent is also invalid if it was given by a representative acting outside their restricted powers during
1064-427: A "right" to ENR technology notwithstanding its potentially grave proliferation implications, therefore, is at the cutting edge of policy and legal debates surrounding the meaning of Article IV and its relation to Articles I, II, and III of the treaty. Countries that have become Parties to the NPT as non-nuclear-weapon States have a strong record of not building nuclear weapons, although some tried and one eventually left
1216-467: A Treaty on general and complete disarmament under strict and effective international control". Article IX : "For the purposes of this Treaty, a nuclear-weapon State is one which has manufactured and exploded a nuclear weapon or other nuclear explosive device prior to 1 January 1967." Article X : Establishes the right to withdraw from the Treaty giving 3 months' notice. It also establishes the duration of
1368-516: A binding international agreement on several grounds. For example, the Japan–Korea treaties of 1905, 1907, and 1910 were protested by several governments as having been essentially forced upon Korea by Japan; they were confirmed as "already null and void " in the 1965 Treaty on Basic Relations between Japan and the Republic of Korea . If an act or lack thereof is condemned under international law,
1520-499: A change is sufficient if unforeseen, if it undermined the "essential basis" of consent by a party if it radically transforms the extent of obligations between the parties, and if the obligations are still to be performed. A party cannot base this claim on change brought about by its own breach of the treaty. This claim also cannot be used to invalidate treaties that established or redrew political boundaries. Cartels ("Cartells", "Cartelle" or "Kartell-Konventionen" in other languages) were
1672-441: A crucial role in generating large amounts of electricity with low carbon emissions, contributing significantly to the global energy mix. Just as conventional thermal power stations generate electricity by harnessing the thermal energy released from burning fossil fuels , nuclear reactors convert the energy released by controlled nuclear fission into thermal energy for further conversion to mechanical or electrical forms. When
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#17327658785681824-644: A disarmament treaty. Rather, it only requires them "to negotiate in good faith". On the other hand, some governments, especially non-nuclear-weapon states belonging to the Non-Aligned Movement , have interpreted Article VI's language as constituting a formal and specific obligation on the NPT-recognized nuclear-weapon states to disarm themselves of nuclear weapons, and argue that these states have failed to meet their obligation. The International Court of Justice (ICJ), in its advisory opinion on
1976-562: A fissile nucleus like uranium-235 or plutonium-239 absorbs a neutron , it splits into lighter nuclei, releasing energy, gamma radiation , and free neutrons, which can induce further fission in a self-sustaining chain reaction . The process is carefully controlled using control rods and neutron moderators to regulate the number of neutrons that continue the reaction, ensuring the reactor operates safely, although inherent control by means of delayed neutrons also plays an important role in reactor output control. The efficiency of nuclear fuel
2128-445: A gas or a liquid metal (like liquid sodium or lead) or molten salt – is circulated past the reactor core to absorb the heat that it generates. The heat is carried away from the reactor and is then used to generate steam. Most reactor systems employ a cooling system that is physically separated from the water that will be boiled to produce pressurized steam for the turbines , like the pressurized water reactor . However, in some reactors
2280-734: A general dispute resolution mechanism, many treaties specify a process outside the convention for arbitrating disputes and alleged breaches. This may by a specially convened panel, by reference to an existing court or panel established for the purpose such as the International Court of Justice , the European Court of Justice or processes such as the Dispute Settlement Understanding of the World Trade Organization . Depending on
2432-469: A general framework for the development of binding greenhouse gas emission limits, followed by the Kyoto Protocol contained the specific provisions and regulations later agreed upon. Treaties may be seen as "self-executing", in that merely becoming a party puts the treaty and all its obligations in action. Other treaties may be non-self-executing and require "implementing legislation"—a change in
2584-442: A large fissile atomic nucleus such as uranium-235 , uranium-233 , or plutonium-239 absorbs a neutron, it may undergo nuclear fission. The heavy nucleus splits into two or more lighter nuclei, (the fission products ), releasing kinetic energy , gamma radiation , and free neutrons . A portion of these neutrons may be absorbed by other fissile atoms and trigger further fission events, which release more neutrons, and so on. This
2736-424: A less effective moderator. In other reactors, the coolant acts as a poison by absorbing neutrons in the same way that the control rods do. In these reactors, power output can be increased by heating the coolant, which makes it a less dense poison. Nuclear reactors generally have automatic and manual systems to scram the reactor in an emergency shut down. These systems insert large amounts of poison (often boron in
2888-445: A non-NWS party except in response to a nuclear attack, or a conventional attack in alliance with a Nuclear Weapons State. However, these undertakings have not been incorporated formally into the treaty, and the exact details have varied over time. The U.S. also had nuclear warheads targeted at North Korea, a non-NWS, from 1959 until 1991. The previous United Kingdom Secretary of State for Defence , Geoff Hoon , has also explicitly invoked
3040-671: A non-nuclear weapon state (NNWS) to acquire nuclear weapons (Article I). NNWS parties to the NPT agree not to "receive", "manufacture", or "acquire" nuclear weapons or to "seek or receive any assistance in the manufacture of nuclear weapons" (Article II). NNWS parties also agree to accept safeguards by the International Atomic Energy Agency (IAEA) to verify that they are not diverting nuclear energy from peaceful uses to nuclear weapons or other nuclear explosive devices (Article III). The five NWS parties have made undertakings not to use their nuclear weapons against
3192-571: A nuclear explosive device before 1 January 1967; these are the United States ( 1945 ), Russia ( 1949 ), the United Kingdom ( 1952 ), France ( 1960 ), and China ( 1964 ). Four other states are known or believed to possess nuclear weapons: India , Pakistan , and North Korea have openly tested and declared that they possess nuclear weapons, while Israel is deliberately ambiguous regarding its nuclear weapons status . The NPT
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#17327658785683344-548: A nuclear weapons program, but has since renounced it and acceded to the treaty in 1991 after destroying its small nuclear arsenal ; after this, the remaining African countries signed the treaty. The former Soviet Republics where nuclear weapons had been based, namely Ukraine, Belarus and Kazakhstan, transferred those weapons to Russia and joined the NPT by 1994 following the signature of the Budapest Memorandum on Security Assurances . Treaty A treaty
3496-597: A number of instances over an extended period of time" to report aspects of its enrichment program. In 1991, Romania reported previously undeclared nuclear activities by the former regime and the IAEA reported this non-compliance to the Security Council for information only. Libya pursued a clandestine nuclear weapons program before abandoning it in December 2003. The IAEA reported Syria's safeguards non-compliance to
3648-570: A number of ways: A kilogram of uranium-235 (U-235) converted via nuclear processes releases approximately three million times more energy than a kilogram of coal burned conventionally (7.2 × 10 joules per kilogram of uranium-235 versus 2.4 × 10 joules per kilogram of coal). The fission of one kilogram of uranium-235 releases about 19 billion kilocalories , so the energy released by 1 kg of uranium-235 corresponds to that released by burning 2.7 million kg of coal. A nuclear reactor coolant – usually water but sometimes
3800-465: A patent on reactors on 19 December 1944. Its issuance was delayed for 10 years because of wartime secrecy. "World's first nuclear power plant" is the claim made by signs at the site of the EBR-I , which is now a museum near Arco, Idaho . Originally called "Chicago Pile-4", it was carried out under the direction of Walter Zinn for Argonne National Laboratory . This experimental LMFBR operated by
3952-773: A pile (hence the name) of graphite blocks, embedded in which was natural uranium oxide 'pseudospheres' or 'briquettes'. Soon after the Chicago Pile, the Metallurgical Laboratory developed a number of nuclear reactors for the Manhattan Project starting in 1943. The primary purpose for the largest reactors (located at the Hanford Site in Washington ), was the mass production of plutonium for nuclear weapons. Fermi and Szilard applied for
4104-407: A planned typical lifetime of 30–40 years, though many of those have received renovations and life extensions of 15–20 years. Some believe nuclear power plants can operate for as long as 80 years or longer with proper maintenance and management. While most components of a nuclear power plant, such as steam generators, are replaced when they reach the end of their useful lifetime, the overall lifetime of
4256-510: A previous treaty or international agreement. A protocol can amend the previous treaty or add additional provisions. Parties to the earlier agreement are not required to adopt the protocol, and this is sometimes made explicit, especially where many parties to the first agreement do not support the protocol. A notable example is the United Nations Framework Convention on Climate Change (UNFCCC), which established
4408-471: A reactor. One such process is delayed neutron emission by a number of neutron-rich fission isotopes. These delayed neutrons account for about 0.65% of the total neutrons produced in fission, with the remainder (termed " prompt neutrons ") released immediately upon fission. The fission products which produce delayed neutrons have half-lives for their decay by neutron emission that range from milliseconds to as long as several minutes, and so considerable time
4560-529: A set of theoretical nuclear reactor designs. These are generally not expected to be available for commercial use before 2040–2050, although the World Nuclear Association suggested that some might enter commercial operation before 2030. Current reactors in operation around the world are generally considered second- or third-generation systems, with the first-generation systems having been retired some time ago. Research into these reactor types
4712-404: A single very long sentence formatted into multiple paragraphs for readability, in which each of the paragraphs begins with a gerund (desiring, recognizing, having, etc.). The High Contracting Parties—referred to as either the official title of the head of state (but not including the personal name), e.g. His Majesty The King of X or His Excellency The President of Y , or alternatively in
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4864-464: A special kind of treaty within the international law of the 17th to 19th centuries. Their purpose was to regulate specific activities of common interest among contracting states that otherwise remained rivals in other areas. They were typically implemented on an administrative level . Similar to the cartels for duels and tournaments , these intergovernmental accords represented fairness agreements or gentlemen's agreements between states . In
5016-599: A testament to the treaty's significance. As of August 2016, 191 states have become parties to the treaty, though North Korea , which acceded in 1985 but never came into compliance, announced its withdrawal from the NPT in 2003, following detonation of nuclear devices in violation of core obligations. Four UN member states have never accepted the NPT, three of which possess or are thought to possess nuclear weapons: India , Israel , and Pakistan . In addition, South Sudan , founded in 2011, has not joined. The treaty defines nuclear-weapon states as those that have built and tested
5168-464: A treaty requires implementing legislation, a state may default on its obligations due to its legislature failing to pass the necessary domestic laws. The language of treaties, like that of any law or contract, must be interpreted when the wording does not seem clear, or it is not immediately apparent how it should be applied in a perhaps unforeseen circumstance. The Vienna Convention states that treaties are to be interpreted "in good faith" according to
5320-519: A treaty, the eschatocol (or closing protocol), is often signaled by language such as "in witness whereof" or "in faith whereof", followed by the words "DONE at", then the site(s) of the treaty's execution and the date(s) of its execution. The date is typically written in its most formal, non-numerical form; for example, the Charter of the United Nations reads "DONE at the city of San Francisco
5472-400: A treaty. However, since the late 19th century, most treaties have followed a fairly consistent format. A treaty typically begins with a preamble describing the "High Contracting Parties" and their shared objectives in executing the treaty, as well as summarizing any underlying events (such as the aftermath of a war in the case of a peace treaty ). Modern preambles are sometimes structured as
5624-432: A treaty. For example, within the United States, agreements between states are compacts and agreements between states and the federal government or between agencies of the government are memoranda of understanding . Another situation can occur when one party wishes to create an obligation under international law, but the other party does not. This factor has been at work with respect to discussions between North Korea and
5776-478: Is a border agreement between the Sumerian city-states of Lagash and Umma around 3100 BC. International agreements were used in some form by most major civilizations, and became increasingly common and more sophisticated during the early modern era . The early 19th century saw developments in diplomacy, foreign policy, and international law reflected by the widespread use of treaties. The 1969 Vienna Convention on
5928-431: Is a formal, legally binding written agreement concluded by sovereign states in international law . International organizations can also be party to an international treaty. A treaty is binding under international law. A treaty may also be known as an international agreement , protocol , covenant , convention , pact , or exchange of letters , among other terms. However, only documents that are legally binding on
6080-413: Is inserted deeper into the reactor, it absorbs more neutrons than the material it displaces – often the moderator. This action results in fewer neutrons available to cause fission and reduces the reactor's power output. Conversely, extracting the control rod will result in an increase in the rate of fission events and an increase in power. The physics of radioactive decay also affects neutron populations in
6232-428: Is known as a nuclear chain reaction . To control such a nuclear chain reaction, control rods containing neutron poisons and neutron moderators are able to change the portion of neutrons that will go on to cause more fission. Nuclear reactors generally have automatic and manual systems to shut the fission reaction down if monitoring or instrumentation detects unsafe conditions. The reactor core generates heat in
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6384-405: Is mined, processed, enriched, used, possibly reprocessed and disposed of is known as the nuclear fuel cycle . Under 1% of the uranium found in nature is the easily fissionable U-235 isotope and as a result most reactor designs require enriched fuel. Enrichment involves increasing the percentage of U-235 and is usually done by means of gaseous diffusion or gas centrifuge . The enriched result
6536-632: Is much higher than fossil fuels; the 5% enriched uranium used in the newest reactors has an energy density 120,000 times higher than coal. Nuclear reactors have their origins in the World War II Allied Manhattan Project . The world's first artificial nuclear reactor, Chicago Pile-1, achieved criticality on 2 December 1942. Early reactor designs sought to produce weapons-grade plutonium for fission bombs , later incorporating grid electricity production in addition. In 1957, Shippingport Atomic Power Station became
6688-415: Is often seen to be based on a central bargain: the NPT non-nuclear-weapon states agree never to acquire nuclear weapons and the NPT nuclear-weapon states in exchange agree to share the benefits of peaceful nuclear technology and to pursue nuclear disarmament aimed at the ultimate elimination of their nuclear arsenals. The treaty is reviewed every five years in meetings called Review Conferences. Even though
6840-401: Is produced. Fission also produces iodine-135 , which in turn decays (with a half-life of 6.57 hours) to new xenon-135. When the reactor is shut down, iodine-135 continues to decay to xenon-135, making restarting the reactor more difficult for a day or two, as the xenon-135 decays into cesium-135, which is not nearly as poisonous as xenon-135, with a half-life of 9.2 hours. This temporary state is
6992-448: Is reaching or crossing their design lifetimes of 30 or 40 years. In 2014, Greenpeace warned that the lifetime extension of ageing nuclear power plants amounts to entering a new era of risk. It estimated the current European nuclear liability coverage in average to be too low by a factor of between 100 and 1,000 to cover the likely costs, while at the same time, the likelihood of a serious accident happening in Europe continues to increase as
7144-416: Is required to determine exactly when a reactor reaches the critical point. Keeping the reactor in the zone of chain reactivity where delayed neutrons are necessary to achieve a critical mass state allows mechanical devices or human operators to control a chain reaction in "real time"; otherwise the time between achievement of criticality and nuclear meltdown as a result of an exponential power surge from
7296-494: The International Atomic Energy Agency (IAEA) Additional Protocol . Critics argue that the NPT cannot stop the proliferation of nuclear weapons or the motivation to acquire them. They express disappointment with the limited progress on nuclear disarmament, where the five authorized nuclear weapons states still have 13,400 warheads in their combined stockpile. Several high-ranking officials within
7448-469: The International Court of Justice . This was done to prevent the practice of secret treaties , which proliferated in the 19th and 20th centuries and often precipitated or exacerbated conflict. Article 103 of the Charter also states that its members' obligations under the Charter outweigh any competing obligations under other treaties. After their adoption, treaties, as well as their amendments, must follow
7600-603: The International Criminal Court and the United Nations , for which they often provide a governing framework. Treaties serve as primary sources of international law and have codified or established most international legal principles since the early 20th century. In contrast with other sources of international law, such as customary international law , treaties are only binding on the parties that have signed and ratified them. Notwithstanding
7752-490: The Manhattan Project . Eventually, the first artificial nuclear reactor, Chicago Pile-1 , was constructed at the University of Chicago , by a team led by Italian physicist Enrico Fermi, in late 1942. By this time, the program had been pressured for a year by U.S. entry into the war. The Chicago Pile achieved criticality on 2 December 1942 at 3:25 PM. The reactor support structure was made of wood, which supported
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#17327658785687904-517: The PWR , BWR and PHWR designs above, and some are more radical departures. The former include the advanced boiling water reactor (ABWR), two of which are now operating with others under construction, and the planned passively safe Economic Simplified Boiling Water Reactor (ESBWR) and AP1000 units (see Nuclear Power 2010 Program ). Rolls-Royce aims to sell nuclear reactors for the production of synfuel for aircraft. Generation IV reactors are
8056-645: The Single Convention on Narcotic Drugs provides that the treaty will terminate if, as a result of denunciations, the number of parties falls below 40. Many treaties expressly forbid withdrawal. Article 56 of the Vienna Convention on the Law of Treaties provides that where a treaty is silent over whether or not it can be denounced there is a rebuttable presumption that it cannot be unilaterally denounced unless: The possibility of withdrawal depends on
8208-524: The U.S. Atomic Energy Commission produced 0.8 kW in a test on 20 December 1951 and 100 kW (electrical) the following day, having a design output of 200 kW (electrical). Besides the military uses of nuclear reactors, there were political reasons to pursue civilian use of atomic energy. U.S. President Dwight Eisenhower made his famous Atoms for Peace speech to the UN General Assembly on 8 December 1953. This diplomacy led to
8360-400: The Vienna Convention on the Law of Treaties if the representative is the head of state, head of government or minister of foreign affairs , no special document is needed, as holding such high office is sufficient. The end of the preamble and the start of the actual agreement is often signaled by the words "have agreed as follows". After the preamble comes numbered articles, which contain
8512-477: The coolant also acts as a neutron moderator . A moderator increases the power of the reactor by causing the fast neutrons that are released from fission to lose energy and become thermal neutrons. Thermal neutrons are more likely than fast neutrons to cause fission. If the coolant is a moderator, then temperature changes can affect the density of the coolant/moderator and therefore change power output. A higher temperature coolant would be less dense, and therefore
8664-586: The use of nuclear weapons in Hiroshima and Nagasaki in 1945, it has been apparent that the development of nuclear capabilities by States could enable them to divert technology and materials for weapons purposes. Thus, the problem of preventing such diversions became a central issue in discussions on peaceful uses of nuclear energy. Initial efforts, which began in 1946, to create an international system enabling all States to have access to nuclear technology under appropriate safeguards, were terminated in 1949 without
8816-402: The "iodine pit." If the reactor has sufficient extra reactivity capacity, it can be restarted. As the extra xenon-135 is transmuted to xenon-136, which is much less a neutron poison, within a few hours the reactor experiences a "xenon burnoff (power) transient". Control rods must be further inserted to replace the neutron absorption of the lost xenon-135. Failure to properly follow such a procedure
8968-404: The "ordinary meaning given to the terms of the treaty in their context and in the light of its object and purpose". International legal experts also often invoke the "principle of maximum effectiveness", which interprets treaty language as having the fullest force and effect possible to establish obligations between the parties. No one party to a treaty can impose its particular interpretation of
9120-490: The 1986 Chernobyl disaster and 2011 Fukushima disaster . As of 2022 , the International Atomic Energy Agency reported there are 422 nuclear power reactors and 223 nuclear research reactors in operation around the world. The US Department of Energy classes reactors into generations, with the majority of the global fleet being Generation II reactors constructed from the 1960s to 1990s, and Generation IV reactors currently in development. Reactors can also be grouped by
9272-572: The IAEA for the application of its safeguards to all nuclear material in all of the state's peaceful nuclear activities and to prevent diversion of such material to nuclear weapons or other nuclear explosive devices. Article IV : 1. Nothing in this Treaty shall be interpreted as affecting the inalienable right of all the Parties to the Treaty to develop research, production and use of nuclear energy for peaceful purposes without discrimination and in conformity with Articles I and II of this Treaty. 2. All
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#17327658785689424-648: The Law of Treaties codified these practices and established rules and guidelines for creating, amending, interpreting, and terminating treaties, and for resolving disputes and alleged breaches. Treaties are roughly analogous to contracts in that they establish the rights and binding obligations of the parties. They vary significantly in form, substance, and complexity and govern a wide variety of matters, such as security, trade, environment, and human rights. Treaties may be bilateral (between two countries) or multilateral (involving more than two countries). They may also be used to establish international institutions, such as
9576-427: The Law of Treaties and customary international law , treaties are not required to follow any standard form. Nevertheless, all valid treaties must comply with the legal principle of pacta sunt servanda (Latin: "agreements must be kept"), under which parties are committed to perform their duties and honor their agreements in good faith . A treaty may also be invalidated, and thus rendered unenforceable, if it violates
9728-517: The Legality of the Threat or Use of Nuclear Weapons , issued 8 July 1996, unanimously interprets the text of Article VI as implying that There exists an obligation to pursue in good faith and bring to a conclusion negotiations leading to nuclear disarmament in all its aspects under strict and effective international control. The ICJ opinion notes that this obligation involves all NPT parties (not just
9880-678: The NPT Review and Extension Conference in May 1995, state parties to the treaty agreed—without a vote—on the treaty's indefinite extension, and decided that review conferences should continue to be held every five years. After Brazil acceded to the NPT in 1998, the only remaining non-nuclear-weapon state which had not signed was Cuba, which joined the NPT (and the Treaty of Tlatelolco NWFZ ) in 2002. Several NPT states parties have given up nuclear weapons or nuclear weapons programs. South Africa undertook
10032-561: The NPT and acquired nuclear weapons. Iraq was found by the IAEA to have violated its safeguards obligations and subject to punitive sanctions by the UN Security Council . North Korea never came into compliance with its NPT safeguards agreement and was cited repeatedly for these violations, and later withdrew from the NPT and tested multiple nuclear devices. Iran was found in non-compliance with its NPT safeguards obligations in an unusual non-consensus decision because it "failed in
10184-740: The NPT as nuclear weapon states (NWS): China (signed 1992), France (1992), the Soviet Union (1968; obligations and rights now assumed by the Russian Federation), the United Kingdom (1968), and the United States (1968), which also happen to be the five permanent members of the United Nations Security Council . These five NWS agree not to transfer "nuclear weapons or other nuclear explosive devices" and "not in any way to assist, encourage, or induce"
10336-403: The NPT is, as its name suggests, principally about nonproliferation, and who worry that "three pillars" language misleadingly implies that the three elements have equivalent importance. Under Article I of the NPT, nuclear-weapon states pledge not to transfer nuclear weapons or other nuclear explosive devices to any recipient or in any way assist, encourage or induce any non-nuclear-weapon state in
10488-511: The NPT's Article VI arguably imposes only a vague obligation on all NPT signatories to move in the general direction of nuclear and total disarmament, saying, "Each of the Parties to the Treaty undertakes to pursue negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament, and on a treaty on general and complete disarmament." Under this interpretation, Article VI does not strictly require all signatories to actually conclude
10640-477: The NPT, and they include the only four additional states believed to possess nuclear weapons. Several additional measures have been adopted to strengthen the NPT and the broader nuclear nonproliferation regime and make it difficult for states to acquire the capability to produce nuclear weapons, including the export controls of the Nuclear Suppliers Group and the enhanced verification measures of
10792-500: The NPT. Such failure, these critics add, provides justification for the non-nuclear-weapon signatories to quit the NPT and develop their own nuclear arsenals. Other observers have suggested that the linkage between proliferation and disarmament may also work the other way, i.e., that the failure to resolve proliferation threats in Iran and North Korea, for instance, will cripple the prospects for disarmament. No current nuclear weapons state,
10944-408: The Parties to the Treaty undertake to facilitate, and have the right to participate in, the fullest possible exchange of equipment, materials and scientific and technological information for the peaceful uses of nuclear energy. Parties to the Treaty in a position to do so shall also co-operate in contributing alone or together with other States or international organizations to the further development of
11096-590: The Swiss ("on the one part") and the EU and its member states ("on the other part"). The treaty establishes rights and obligations between the Swiss and the EU and the member states severally—it does not establish any rights and obligations amongst the EU and its member states. A multilateral treaty is concluded among several countries, establishing rights and obligations between each party and every other party. Multilateral treaties may be regional or may involve states across
11248-606: The Treaty (25 years before 1995 Extension Initiative). The impetus behind the NPT was concern for the safety of a world with many nuclear weapon states. It was recognized that the Cold War deterrent relationship between just the United States and the Soviet Union was fragile. Having more nuclear-weapon states would reduce security for all, multiplying the risks of miscalculation, accidents, unauthorized use of weapons, escalation in tensions, and nuclear conflict. Moreover, since
11400-736: The U.S. military sought other uses for nuclear reactor technology. Research by the Army led to the power stations for Camp Century, Greenland and McMurdo Station, Antarctica Army Nuclear Power Program . The Air Force Nuclear Bomber project resulted in the Molten-Salt Reactor Experiment . The U.S. Navy succeeded when they steamed the USS Nautilus (SSN-571) on nuclear power 17 January 1955. The first commercial nuclear power station, Calder Hall in Sellafield , England
11552-535: The UN Security Council, which did not take action. In some regions, the fact that all neighbors are verifiably free of nuclear weapons reduces any pressure individual states might feel to build those weapons themselves, even if neighbors are known to have peaceful nuclear energy programs that might otherwise be suspicious. In this, the treaty works as designed. In 2004, Mohamed ElBaradei said that by some estimates thirty-five to forty states could have
11704-603: The United Nations have said that they can do little to stop states using nuclear reactors to produce nuclear weapons. The NPT consists of a preamble and eleven articles. Although the concept of "pillars" is not expressed anywhere in the NPT, the treaty is nevertheless sometimes interpreted as a three-pillar system, with an implicit balance among them: These pillars are interrelated and mutually reinforcing. An effective nonproliferation regime whose members comply with their obligations provides an essential foundation for progress on disarmament and makes possible greater cooperation on
11856-472: The United States does not engage in or encourage reprocessing. Reactors are also used in nuclear propulsion of vehicles. Nuclear marine propulsion of ships and submarines is largely restricted to naval use. Reactors have also been tested for nuclear aircraft propulsion and spacecraft propulsion . Reactor safety is maintained through various systems that control the rate of fission. The insertion of control rods, which absorb neutrons, can rapidly decrease
12008-533: The United States over security guarantees and nuclear proliferation . The definition of the English word "treaty" varies depending on the legal and political context; in some jurisdictions, such as the United States, a treaty is specifically an international agreement that has been ratified, and thus made binding, per the procedures established under domestic law. While the Vienna Convention provides
12160-694: The United States, cartels governed humanitarian actions typically carried out by cartel ships were dispatched for missions, such as to carry communications or prisoners between belligerents . From the European history, a broader range of purposes is known. These "cartels" often reflected the cohesion of authoritarian ruling classes against their own unruly citizens. Generally, the European governments concluded - while curbing their mutual rivalries partially - cooperation agreements, which should apply generally or only in case of war: The measures against criminals and unruly citizens were to be conducted regardless of
12312-701: The achievement of this objective, due to serious political differences between the major Powers. By then, both the United States and the former Soviet Union had tested nuclear weapons, and were beginning to build their stockpiles. In December 1953, US President Dwight D. Eisenhower , in his " Atoms for Peace " proposal, presented to the eighth session of the United Nations General Assembly, urged that an international organization be established to disseminate peaceful nuclear technology, while guarding against development of weapons capabilities in additional countries. His proposal resulted in 1957 in
12464-417: The act will not assume international legality even if approved by internal law. This means that in case of a conflict with domestic law, international law will always prevail. A party's consent to a treaty is invalid if it had been given by an agent or body without power to do so under that state's domestic laws . States are reluctant to inquire into the internal affairs and processes of other states, and so
12616-409: The applications of nuclear energy for peaceful purposes, especially in the territories of non-nuclear-weapon States Party to the Treaty, with due consideration for the needs of the developing areas of the world. Article VI : Each party "undertakes to pursue negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament, and on
12768-569: The area was contaminated, like Fukushima, Three Mile Island, Sellafield, and Chernobyl. The British branch of the French concern EDF Energy , for example, extended the operating lives of its Advanced Gas-cooled Reactors (AGR) with only between 3 and 10 years. All seven AGR plants were expected to be shut down in 2022 and in decommissioning by 2028. Hinkley Point B was extended from 40 to 46 years, and closed. The same happened with Hunterston B , also after 46 years. An increasing number of reactors
12920-405: The argument goes, would seriously consider eliminating its last nuclear weapons without high confidence that other countries would not acquire them. Some observers have even suggested that the very progress of disarmament by the superpowers—which has led to the elimination of thousands of weapons and delivery systems—could eventually make the possession of nuclear weapons more attractive by increasing
13072-795: The beginning of his quest to produce the Einstein-Szilárd letter to alert the U.S. government. Shortly after, Nazi Germany invaded Poland in 1939, starting World War II in Europe. The U.S. was not yet officially at war, but in October, when the Einstein-Szilárd letter was delivered to him, Roosevelt commented that the purpose of doing the research was to make sure "the Nazis don't blow us up." The U.S. nuclear project followed, although with some delay as there remained skepticism (some of it from Enrico Fermi ) and also little action from
13224-458: The choices of coolant and moderator. Almost 90% of global nuclear energy comes from pressurized water reactors and boiling water reactors , which use water as a coolant and moderator. Other designs include heavy water reactors , gas-cooled reactors , and fast breeder reactors , variously optimizing efficiency, safety, and fuel type , enrichment , and burnup . Small modular reactors are also an area of current development. These reactors play
13376-467: The complexities of handling actinides , but significant scientific and technical obstacles remain. Despite research having started in the 1950s, no commercial fusion reactor is expected before 2050. The ITER project is currently leading the effort to harness fusion power. Thermal reactors generally depend on refined and enriched uranium . Some nuclear reactors can operate with a mixture of plutonium and uranium (see MOX ). The process by which uranium ore
13528-523: The content of the treaty itself. Invalidation is separate from withdrawal, suspension, or termination (addressed above), which all involve an alteration in the consent of the parties of a previously valid treaty rather than the invalidation of that consent in the first place. Nuclear reactor A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction . Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion . When
13680-472: The dates on which the respective parties ratified the treaty and on which it came into effect for each party. Bilateral treaties are concluded between two states or entities. It is possible for a bilateral treaty to have more than two parties; for example, each of the bilateral treaties between Switzerland and the European Union (EU) has seventeen parties: The parties are divided into two groups,
13832-423: The development of nuclear weapons. As the commercially popular light water reactor nuclear power station uses enriched uranium fuel, it follows that states must be able either to enrich uranium or purchase it on an international market. Mohamed ElBaradei , then Director General of the International Atomic Energy Agency , has called the spread of enrichment and reprocessing capabilities the " Achilles' heel " of
13984-567: The dissemination of reactor technology to U.S. institutions and worldwide. The first nuclear power plant built for civil purposes was the AM-1 Obninsk Nuclear Power Plant , launched on 27 June 1954 in the Soviet Union . It produced around 5 MW (electrical). It was built after the F-1 (nuclear reactor) which was the first reactor to go critical in Europe, and was also built by the Soviet Union. After World War II,
14136-418: The domestic law of a state party that will direct or enable it to fulfill treaty obligations. An example of a treaty requiring such legislation would be one mandating local prosecution by a party for particular crimes. The division between the two is often unclear and subject to disagreements within a government, since a non-self-executing treaty cannot be acted on without the proper change in domestic law; if
14288-428: The early 1960s. The structure of a treaty to uphold nuclear non-proliferation as a norm of international behaviour had become clear by the mid-1960s, and by 1968 final agreement had been reached on a Treaty that would prevent the proliferation of nuclear weapons, enable cooperation for the peaceful use of nuclear energy, and further the goal of achieving nuclear disarmament. It was opened for signature in 1968, with Finland
14440-585: The effectiveness and improve the efficiency of the IAEA safeguards system culminated in the approval of the Model Additional Protocol by the IAEA Board of Governors in May 1997. Within the framework of the United Nations, the principle of nuclear non-proliferation was addressed in negotiations as early as 1957. The NPT process was launched by Frank Aiken , Irish Minister for External Affairs, in 1958. The NPT gained significant momentum in
14592-494: The energy of the neutrons that sustain the fission chain reaction : In principle, fusion power could be produced by nuclear fusion of elements such as the deuterium isotope of hydrogen . While an ongoing rich research topic since at least the 1940s, no self-sustaining fusion reactor for any purpose has ever been built. Used by thermal reactors: In 2003, the French Commissariat à l'Énergie Atomique (CEA)
14744-471: The establishment of the International Atomic Energy Agency (IAEA), which was charged with the dual responsibility for promotion and control of nuclear technology. IAEA technical activities began in 1958. An interim safeguards system for small nuclear reactors, put in place in 1961, was replaced in 1964 by a system covering larger installations and, over the following years, was expanded to include additional nuclear facilities. In recent years, efforts to strengthen
14896-515: The first State to sign . Accession became nearly universal after the end of the Cold War and of South African apartheid . In 1992, The People's Republic of China and France acceded to the NPT, the last of the five nuclear powers recognized by the treaty to do so. The treaty provided, in article X, for a conference to be convened 25 years after its entry into force to decide whether the treaty should continue in force indefinitely, or be extended for an additional fixed period or periods. Accordingly, at
15048-642: The first reactor dedicated to peaceful use; in Russia, in 1954, the first small nuclear power reactor APS-1 OBNINSK reached criticality. Other countries followed suit. Heat from nuclear fission is passed to a working fluid coolant (water or gas), which in turn runs through turbines . In commercial reactors, turbines drive electrical generator shafts. The heat can also be used for district heating , and industrial applications including desalination and hydrogen production . Some reactors are used to produce isotopes for medical and industrial use. Reactors pose
15200-407: The fission process generates heat, some of which can be converted into usable energy. A common method of harnessing this thermal energy is to use it to boil water to produce pressurized steam which will then drive a steam turbine that turns an alternator and generates electricity. Modern nuclear power plants are typically designed for a lifetime of 60 years, while older reactors were built with
15352-529: The form of boric acid ) into the reactor to shut the fission reaction down if unsafe conditions are detected or anticipated. Most types of reactors are sensitive to a process variously known as xenon poisoning, or the iodine pit . The common fission product Xenon-135 produced in the fission process acts as a neutron poison that absorbs neutrons and therefore tends to shut the reactor down. Xenon-135 accumulation can be controlled by keeping power levels high enough to destroy it by neutron absorption as fast as it
15504-407: The form of " Government of Z "—are enumerated, along with the full names and titles of their plenipotentiary representatives; a boilerplate clause describes how each party's representatives have communicated (or exchanged) their "full powers" (i.e., the official documents appointing them to act on behalf of their respective high contracting party) and found them in good or proper form. However, under
15656-424: The fuel rods. This allows the reactor to be constructed with an excess of fissionable material, which is nevertheless made relatively safe early in the reactor's fuel burn cycle by the presence of the neutron-absorbing material which is later replaced by normally produced long-lived neutron poisons (far longer-lived than xenon-135) which gradually accumulate over the fuel load's operating life. The energy released in
15808-450: The goal of disarmament by the nuclear-weapon states. The NPT's preamble contains language affirming the desire of treaty signatories to ease international tension and strengthen international trust so as to create someday the conditions for a halt to the production of nuclear weapons, and treaty on general and complete disarmament that liquidates, in particular, nuclear weapons and their delivery vehicles from national arsenals. The wording of
15960-447: The idea of nuclear fission as a neutron source, since that process was not yet discovered. Szilárd's ideas for nuclear reactors using neutron-mediated nuclear chain reactions in light elements proved unworkable. Inspiration for a new type of reactor using uranium came from the discovery by Otto Hahn , Lise Meitner , and Fritz Strassmann in 1938 that bombardment of uranium with neutrons (provided by an alpha-on-beryllium fusion reaction,
16112-606: The knowledge to develop nuclear weapons. Article I : Each nuclear-weapons state (NWS) undertakes not to transfer, to any recipient, nuclear weapons, or other nuclear explosive devices, and not to assist any non-nuclear weapon state to manufacture or acquire such weapons or devices. Article II : Each non-NWS party undertakes not to receive, from any source, nuclear weapons, or other nuclear explosive devices; not to manufacture or acquire such weapons or devices; and not to receive any assistance in their manufacture. Article III : Each non-NWS party undertakes to conclude an agreement with
16264-400: The legal obligation and its effects on the reserving state. These must be included at the time of signing or ratification, i.e., "a party cannot add a reservation after it has already joined a treaty". Article 19 of the Vienna Convention on the law of Treaties in 1969. Originally, international law was unaccepting of treaty reservations, rejecting them unless all parties to the treaty accepted
16416-404: The legal obligations of states, one party to the original treaty and one party to the amended treaty, the states will only be bound by the terms they both agreed upon. Treaties can also be amended informally by the treaty executive council when the changes are only procedural, technical change in customary international law can also amend a treaty, where state behavior evinces a new interpretation of
16568-434: The legal obligations under the treaty. Minor corrections to a treaty may be adopted by a procès-verbal ; but a procès-verbal is generally reserved for changes to rectify obvious errors in the text adopted, i.e., where the text adopted does not correctly reflect the intention of the parties adopting it. In international law and international relations, a protocol is generally a treaty or international agreement that supplements
16720-476: The manufacture or acquisition of a nuclear weapon. Under Article II of the NPT, non-nuclear-weapon states pledge not to acquire or exercise control over nuclear weapons or other nuclear explosive devices and not to seek or receive assistance in the manufacture of such devices. Under Article III of the Treaty, non-nuclear-weapon states pledge to accept IAEA safeguards to verify that their nuclear activities serve only peaceful purposes. Five states are recognized by
16872-445: The meaning in context, these judicial bodies may review the preparatory work from the negotiation and drafting of the treaty as well as the final, signed treaty itself. One significant part of treaty-making is that signing a treaty implies a recognition that the other side is a sovereign state and that the agreement being considered is enforceable under international law. Hence, nations can be very careful about terming an agreement to be
17024-434: The nationality and origin of the relevant persons. If necessary, national borders could be crossed by police forces of the respective neighboring country for capture and arrest . In the course of the 19th century, the term "cartel" (or "Cartell") gradually disappeared for intergovernmental agreements under international law. Instead, the term "convention" was used. An otherwise valid and agreed upon treaty may be rejected as
17176-411: The negotiations, if the other parties to the treaty were notified of those restrictions prior to his or her signing. Articles 46–53 of the Vienna Convention on the Law of Treaties set out the only ways that treaties can be invalidated—considered unenforceable and void under international law. A treaty will be invalidated due to either the circumstances by which a state party joined the treaty or due to
17328-449: The normal nuclear chain reaction, would be too short to allow for intervention. This last stage, where delayed neutrons are no longer required to maintain criticality, is known as the prompt critical point. There is a scale for describing criticality in numerical form, in which bare criticality is known as zero dollars and the prompt critical point is one dollar , and other points in the process interpolated in cents. In some reactors,
17480-477: The nuclear nonproliferation regime. As of 2007, 13 states have an enrichment capability. During the 1960s and 1970s many states, almost 60, were supplied with research reactors fuelled by weapon grade highly enriched uranium (HEU) through the United States Atoms for Peace program and a similar Soviet Union program. In the 1980s a program to convert HEU research reactors to use low enriched fuel
17632-509: The nuclear weapon states) and does not suggest a specific time frame for nuclear disarmament. Critics of the NPT-recognized nuclear-weapon states (the United States, Russia, China, France, and the United Kingdom) sometimes argue that what they view as the failure of the NPT-recognized nuclear weapon states to disarm themselves of nuclear weapons, especially in the post–Cold War era , has angered some non-nuclear-weapon NPT signatories of
17784-600: The official legal procedures of the United Nations, as applied by the Office of Legal Affairs , including signature, ratification and entry into force . In function and effectiveness, the UN has been compared to the United States federal government under the Articles of Confederation . Reservations are essentially caveats to a state's acceptance of a treaty. Reservations are unilateral statements purporting to exclude or to modify
17936-581: The opportunity for the nuclear chain reaction that Szilárd had envisioned six years previously. On 2 August 1939, Albert Einstein signed a letter to President Franklin D. Roosevelt (written by Szilárd) suggesting that the discovery of uranium's fission could lead to the development of "extremely powerful bombs of a new type", giving impetus to the study of reactors and fission. Szilárd and Einstein knew each other well and had worked together years previously, but Einstein had never thought about this possibility for nuclear energy until Szilard reported it to him, at
18088-408: The option to accept those reservations, object to them, or object and oppose them. If the state accepts them (or fails to act at all), both the reserving state and the accepting state are relieved of the reserved legal obligation as concerns their legal obligations to each other (accepting the reservation does not change the accepting state's legal obligations as concerns other parties to the treaty). If
18240-415: The parties are considered treaties under international law. Treaties vary in their obligations (the extent to which states are bound to the rules), precision (the extent to which the rules are unambiguous), and delegation (the extent to which third parties have authority to interpret, apply and make rules). Treaties are among the earliest manifestations of international relations ; the first known example
18392-402: The peaceful use of nuclear energy. With the right to access the benefits of peaceful nuclear technology comes the responsibility of nonproliferation. Progress on disarmament reinforces efforts to strengthen the nonproliferation regime and to enforce compliance with obligations, thereby also facilitating peaceful nuclear cooperation. The "pillars" concept has been questioned by some who believe that
18544-428: The perceived strategic value of a small arsenal. As one U.S. official and NPT expert warned in 2007, "logic suggests that as the number of nuclear weapons decreases, the ' marginal utility ' of a nuclear weapon as an instrument of military power increases. At the extreme, which it is precisely disarmament's hope to create, the strategic utility of even one or two nuclear weapons would be huge." NPT Article IV acknowledges
18696-406: The physics of radioactive decay and are simply accounted for during the reactor's operation, while others are mechanisms engineered into the reactor design for a distinct purpose. The fastest method for adjusting levels of fission-inducing neutrons in a reactor is via movement of the control rods . Control rods are made of so-called neutron poisons and therefore absorb neutrons. When a control rod
18848-414: The possibility of the use of the country's nuclear weapons in response to a non-conventional attack by " rogue states ". In January 2006, President Jacques Chirac of France indicated that an incident of state-sponsored terrorism on France could trigger a small-scale nuclear retaliation aimed at destroying the "rogue state's" power centers. Security provided by extended nuclear deterrence (also known as
19000-463: The power plant is limited by the life of components that cannot be replaced when aged by wear and neutron embrittlement , such as the reactor pressure vessel. At the end of their planned life span, plants may get an extension of the operating license for some 20 years and in the US even a "subsequent license renewal" (SLR) for an additional 20 years. Even when a license is extended, it does not guarantee
19152-572: The reactor fleet grows older. The neutron was discovered in 1932 by British physicist James Chadwick . The concept of a nuclear chain reaction brought about by nuclear reactions mediated by neutrons was first realized shortly thereafter, by Hungarian scientist Leó Szilárd , in 1933. He filed a patent for his idea of a simple reactor the following year while working at the Admiralty in London, England. However, Szilárd's idea did not incorporate
19304-416: The reactor will continue to operate, particularly in the face of safety concerns or incident. Many reactors are closed long before their license or design life expired and are decommissioned . The costs for replacements or improvements required for continued safe operation may be so high that they are not cost-effective. Or they may be shut down due to technical failure. Other ones have been shut down because
19456-437: The reactor's output, while other systems automatically shut down the reactor in the event of unsafe conditions. The buildup of neutron-absorbing fission products like xenon-135 can influence reactor behavior, requiring careful management to prevent issues such as the iodine pit , which can complicate reactor restarts. There have been two reactor accidents classed as an International Nuclear Event Scale Level 7 "major accident":
19608-409: The reserving state is a party to the treaty at all. There are three ways an existing treaty can be amended. First, a formal amendment requires State parties to the treaty to go through the ratification process all over again. The re- negotiation of treaty provisions can be long and protracted, and often some parties to the original treaty will not become parties to the amended treaty. When determining
19760-527: The right of all Parties to develop nuclear energy for peaceful purposes and to benefit from international cooperation in this area, in conformity with their nonproliferation obligations. Article IV also encourages such cooperation. This so-called third pillar provides for the transfer of nuclear technology and materials to NPT Parties for peaceful purposes in the development of civilian nuclear energy programs in those countries, subject to IAEA safeguards to demonstrate that their nuclear programs are not being used for
19912-456: The same reservations. However, in the interest of encouraging the largest number of states to join treaties, a more permissive rule regarding reservations has emerged. While some treaties still expressly forbid any reservations, they are now generally permitted to the extent that they are not inconsistent with the goals and purposes of the treaty. When a state limits its treaty obligations through reservations, other states party to that treaty have
20064-647: The small number of officials in the government who were initially charged with moving the project forward. The following year, the U.S. Government received the Frisch–Peierls memorandum from the UK, which stated that the amount of uranium needed for a chain reaction was far lower than had previously been thought. The memorandum was a product of the MAUD Committee , which was working on the UK atomic bomb project, known as Tube Alloys , later to be subsumed within
20216-410: The state opposes, the parts of the treaty affected by the reservation drop out completely and no longer create any legal obligations on the reserving and accepting state, again only as concerns each other. Finally, if the state objects and opposes, there are no legal obligations under that treaty between those two state parties whatsoever. The objecting and opposing state essentially refuses to acknowledge
20368-416: The substance of the parties' actual agreement. Each article heading usually encompasses a paragraph. A long treaty may further group articles under chapter headings. Modern treaties, regardless of subject matter, usually contain articles governing where the final authentic copies of the treaty will be deposited and how any subsequent disputes as to their interpretation will be peacefully resolved. The end of
20520-701: The terms of the treaty and its travaux preparatory. It has, for example, been held that it is not possible to withdraw from the International Covenant on Civil and Political Rights . When North Korea declared its intention to do this the Secretary-General of the United Nations, acting as registrar, said that original signatories of the ICCPR had not overlooked the possibility of explicitly providing for withdrawal, but rather had deliberately intended not to provide for it. Consequently, withdrawal
20672-439: The treaty is automatically terminated if certain defined conditions are met. Some treaties are intended by the parties to be only temporarily binding and are set to expire on a given date. Other treaties may self-terminate if the treaty is meant to exist only under certain conditions. A party may claim that a treaty should be terminated, even absent an express provision, if there has been a fundamental change in circumstances. Such
20824-593: The treaty itself. A treaty breach does not automatically suspend or terminate treaty relations, however. It depends on how the other parties regard the breach and how they resolve to respond to it. Sometimes treaties will provide for the seriousness of a breach to be determined by a tribunal or other independent arbiter. An advantage of such an arbiter is that it prevents a party from prematurely and perhaps wrongfully suspending or terminating its own obligations due to another's an alleged material breach. Treaties sometimes include provisions for self-termination, meaning that
20976-562: The treaty upon the other parties. Consent may be implied, however, if the other parties fail to explicitly disavow that initially unilateral interpretation, particularly if that state has acted upon its view of the treaty without complaint. Consent by all parties to the treaty to a particular interpretation has the legal effect of adding another clause to the treaty – this is commonly called an "authentic interpretation". International tribunals and arbiters are often called upon to resolve substantial disputes over treaty interpretations. To establish
21128-571: The treaty was negotiated by the Eighteen Nation Committee on Disarmament , a United Nations -sponsored organization based in Geneva , Switzerland. Opened for signature in 1968, the treaty entered into force in 1970. As required by the text, after twenty-five years, NPT parties met in May 1995 and agreed to extend the treaty indefinitely. More countries are parties to the NPT than any other arms limitation and disarmament agreement,
21280-613: The treaty was originally conceived with a limited duration of 25 years, the signing parties decided, by consensus, to unconditionally extend the treaty indefinitely during the Review Conference in New York City on 11 May 1995, in the culmination of U.S. government efforts led by Ambassador Thomas Graham Jr. At the time the NPT was proposed, there were predictions of 25–30 nuclear weapon states within 20 years. Instead, over forty years later, five states are not parties to
21432-411: The treaty, such a process may result in financial penalties or other enforcement action. Treaties are not necessarily permanently binding upon the signatory parties. As obligations in international law are traditionally viewed as arising only from the consent of states, many treaties expressly allow a state to withdraw as long as it follows certain procedures of notification ("denunciation"). For example,
21584-447: The treaty. Multilateral treaties typically continue even after the withdrawal of one member, unless the terms of the treaty or mutual agreement causes its termination. If a party has materially violated or breached its treaty obligations, the other parties may invoke this breach as grounds for temporarily suspending their obligations to that party under the treaty. A material breach may also be invoked as grounds for permanently terminating
21736-456: The twenty-sixth day of June, one thousand nine hundred and forty-five". If applicable, a treaty will note that it is executed in multiple copies in different languages, with a stipulation that the versions in different languages are equally authentic. The signatures of the parties' representatives follow at the very end. When the text of a treaty is later reprinted, such as in a collection of treaties currently in effect, an editor will often append
21888-424: The water for the steam turbines is boiled directly by the reactor core ; for example the boiling water reactor . The rate of fission reactions within a reactor core can be adjusted by controlling the quantity of neutrons that are able to induce further fission events. Nuclear reactors typically employ several methods of neutron control to adjust the reactor's power output. Some of these methods arise naturally from
22040-531: The world. Treaties of "mutual guarantee" are international compacts, e.g., the Treaty of Locarno which guarantees each signatory against attack from another. The United Nations has extensive power to convene states to enact large-scale multilateral treaties and has experience doing so. Under the United Nations Charter , which is itself a treaty, treaties must be registered with the UN to be invoked before it, or enforced in its judiciary organ,
22192-481: Was a key step in the Chernobyl disaster . Reactors used in nuclear marine propulsion (especially nuclear submarines ) often cannot be run at continuous power around the clock in the same way that land-based power reactors are normally run, and in addition often need to have a very long core life without refueling . For this reason many designs use highly enriched uranium but incorporate burnable neutron poison in
22344-437: Was declared a major emphasis of U.S. policy in 2004 to prevent the further spread of uranium enrichment and plutonium reprocessing (a.k.a. "ENR") technology. Countries possessing ENR capabilities, it is feared, have what is in effect the option of using this capability to produce fissile material for weapons use on demand, thus giving them what has been termed a "virtual" nuclear weapons program. The degree to which NPT members have
22496-434: Was not possible. In practice, states sometimes use their sovereignty to declare their withdrawal from and stop following the terms of a treaty even if this violates the terms of the treaty. Other parties may accept this outcome, may consider the state to be untrustworthy in future dealings, or may retaliate with sanctions or military action. Withdrawal by one party from a bilateral treaty is typically considered to terminate
22648-788: Was officially started by the Generation ;IV International Forum (GIF) based on eight technology goals. The primary goals being to improve nuclear safety, improve proliferation resistance, minimize waste and natural resource utilization, and to decrease the cost to build and run such plants. Generation V reactors are designs which are theoretically possible, but which are not being actively considered or researched at present. Though some generation V reactors could potentially be built with current or near term technology, they trigger little interest for reasons of economics, practicality, or safety. Controlled nuclear fusion could in principle be used in fusion power plants to produce power without
22800-463: Was opened in 1956 with an initial capacity of 50 MW (later 200 MW). The first portable nuclear reactor "Alco PM-2A" was used to generate electrical power (2 MW) for Camp Century from 1960 to 1963. All commercial power reactors are based on nuclear fission . They generally use uranium and its product plutonium as nuclear fuel , though a thorium fuel cycle is also possible. Fission reactors can be divided roughly into two classes, depending on
22952-426: Was started in the United States due to proliferation concerns. However 26 states possessed more than 1 kg of civilian HEU in 2015, and as of 2016 the stocks of HEU for civilian research were 60 tonnes, with 74 research reactors still using HEU. Because the availability of fissile material has long been considered the principal obstacle to, and "pacing element" for, a country's nuclear weapons development effort, it
23104-649: Was the first to refer to "Gen II" types in Nucleonics Week . The first mention of "Gen III" was in 2000, in conjunction with the launch of the Generation IV International Forum (GIF) plans. "Gen IV" was named in 2000, by the United States Department of Energy (DOE), for developing new plant types. More than a dozen advanced reactor designs are in various stages of development. Some are evolutionary from
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