国会收到核弹头计划

A white paper describes plans for a joint warhead.

汉斯·克里斯滕森（Hans M. Kristensen）

国家核安全管理局（NNSA）已向国会派出一份白皮书，描述了在民兵三世洲际弹道导弹（ICBM）上延长W78弹头寿命的计划。

根据论文W78 Life Extension Program Description and Work Scope, a Phase 6.1 study would begin in February 2011 and seek to produce the first warhead in 2021.

Although focused on extending the life of the W78 warhead itself, the study includes an adaptable warhead option to join the W78 and W88 warheads for the purpose of producing a modified warhead that can be deployed on both the Minuteman and the Navy’s Trident II D5 sea-launched ballistic missile (SLBM).

A Joint Warhead

The NNSA white paper states that the Phase 6.1 study will explore the “W78 Military Characteristics (MCs) including military requirements for a system that could be fielded with both the Mk12A and Mk5 reentry systems.”

A joint warhead option raises important questions: How different will the new warhead be compared with the current W78 and W88 types? Will it be closer to the W78 or the W88 design? Will it be a “reliable replacement warhead”?

白皮书的一部分表明，关节弹头可能比W88更接近W78。实际上，1970年代W78的最初要求是ICBM和SLBM部署：

“计划中的方法是延长W78使用寿命的重要机会，纳入现代安全，保障和控制功能，如果W78 LEP也能够address the requirements of the W88，提高效率并降低成本。实际上，W78的原始MC（1974年出版）定义了一项要求，但在技​​术上未修复，用于用于民兵三世和Trident II交付系统的核弹头。那时这是不可行的，但是很可能今天是可行的。”（添加了强调）

白皮书承诺：“ W78 LEP将仅根据先前测试的设计使用核部件，并且不会支持新的军事任务或提供新的军事能力。”

但是对于联合弹头选项,W78地蜡部署on SLBMs will obviously have to meet similar military requirements as the W88. Both warheads are hard-target kill weapons, yet the yield of the W88 is more than 100 kt greater than the W78 (see table). So unless the military reduces its requirements for the SLBM mission, then the capability of the W78 LEP warhead obviously would have to be increased to meet both missions.

W78和W88弹头轮廓

* Pits (plutonium cores) for W88 replacement warheads are currently being produced at the Los Alamos National Laboratory.

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The W78 and W88 designs currently have “single yield” so one possibility could be to add more yield options to a joint warhead to meet both missions. A new Arming, Fuzing and firing (AF&F) unit might also provide new targeting flexibility that improves the kill capability of the warhead (类似于目前正在生产的MK4A/W76-1 SLBM弹头). Or a decision to increase the accuracy of the missiles could reduce the yield requirement.

Regardless of which design option is chosen, a joint warhead would appear to require some new military capabilities.

NNSA先前来自2009财年的弹头翻新图表没有列出W78 LEP的新AF＆F，也没有列出W78或W88弹头的新保证功能。但是2011财年的图表库存管理管理计划（SSMP）列出了所有未来生命延伸计划的新的AF＆F和保证功能（请参阅图表）。

Scheduled W78 and W88 Life Extension Programs

Following immediately after scheduled completion of the W76 and W61 life extension programs, the administration is planning life extension programs for the W78 and W88 warheads. A joint ICBM-SLBM warhead would combine the W78 and W88 programs.

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How Many Warheads?

如果联合弹头成为W78的修改版本，那么W88会发生什么？核姿势审查指出，W78 LEP研究将检查“也可能在SLBMS上使用弹头的可能性减少弹头类型的数量.” (Emphasis added) And a joint warhead, the NNSA white paper states, “could provide opportunities to reduce further预订warheads.” (Emphasis added)

That language suggests an intention to replace the W88. If so, how many W78 LEP warheads would be needed for both missions?

在1979年至1982年之间，生产了近1,000枚W78弹头，但目前只有250张左右的弹头部署了350次储备，总计约600 W78剩余的股票。多年来，在破坏性质量控制实验中已经消耗了数百个W78。

在1989年至1991年之间生产了大约400个W88，其中约有380个。目前，洛斯阿拉莫斯国家实验室（Los Alamos National Laboratory）的新生产弹头替代了破坏性质量控制实验中失去的弹头。

假设部署的ICBMS和SLBM的数量分别将缩小至420和240，在接下来的十年中，新的联合弹头的潜在数量可能约为800（除了在两个平台上部署的W87和W76-1S之外）。

库存多样性和可靠性

减少弹头的策略类型与布什政府的RRW计划不同，该计划argued弹头的替代对于保存库存的“多样性”至关重要。这样的想法是，每个分娩平台的两种弹头类型将保护灾难性的技术弹头缺陷，使三合会的一条腿瘫痪。

Since a joint ICBM/SLBM warhead would reduce the warhead types for those platforms from four to three, a technical failure of the joint warhead would significantly affect the capability of both legs, instead of just one of them. That, ironically, could increase the vulnerability of the two legs and drive a requirement to maintain more W87 and W76-1 warheads in reserve than otherwise.

The administration is rushing a W88 AF&F replacement in 2018-2919, well ahead of the full LEP schedule.

白皮书指出，“ W78 LEP将仅根据先前测试的设计使用核部件”，这也是NPR的承诺。但是，添加新组件（例如AF＆F）以及安全和安全功能可能会为预测武器可靠性带来严重的风险。

武器实验室探索的一些安全功能包括用不敏感的高爆炸物（IHE）代替化学高爆炸物（CHE），并为弹头增加多点安全性。

Except for the W87, all U.S. ballistic missile warheads have conventional high explosives, potentially making them less safe than the W87. The newest missile warhead, the W88, was designed with the less safe explosive to reduce weight in order to increase the number of warheads that would be delivered by each missile. Using the W87 to replace the W88 would seem a better option (although the W87 yield is less than the W78), but there are too few W87s in the stockpile to load both ICBMs and SLBMs and the warhead is not scheduled for an LEP until the late-2030s. Another way to increase safety is to handle the warheads less and improve handling procedures. Deploying warheads on high alert, for example, significantly increases safety risks.

所有弹头目前单点安全,制作h means if the high explosive is detonated at any single point, there will be less than one chance in a million that more yield will result than the equivalent to exploding four pounds of high explosives. Multi-point safety would ensure the same safety margin if multiple high explosives detonated simultaneously, but that would require significant changes to the warhead design and potentially decrease confidence in its reliability. Besides, no warhead accident has ever resulted in a nuclear yield.

换句话说，与生产新的联合弹头相关的风险和不确定性很多，而且很明显，它们将允许减少储备金的数量。

成本预测

NNSA白皮书不包括W78 LEP的成本预测，而是2011财年库存管理管理计划做。到2025年，该计划预计将耗资超过40亿美元，或每名库存的W78弹头大约700万美元。

Projected W78 Life Extension Program Costs

The administration projects the cost of the W78 life extension program will reach more than $4 billion through 2025. A joint ICBM-SLBM warhead would increase costs significantly.

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结合W78和W88将大大增加此成本预测。

The administration’s budget includes $26 million to begin the Phase 6.1 study in February 2011, and STRATCOM apparently has already completed its assessment for a joint warhead but has not yet released its report.

但是，直到五角大楼为国会提供了对NNSA寻求联合弹头选择的明确需求或军事要求之前，第6.1阶段的研究才能开始。有很多问题需要回答。

This publication was made possible by a grant from Carnegie Corporation of New York and Ploughshares Fund. The statements made and views expressed are solely the responsibility of the author.