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Senate Debates Nuclear Bunker Buster, Part II 

By Ivan Oelrich

Three weeks ago, Senator Feinstein introduced an amendment to the Energy bill to remove funding for the Robust Nuclear Earth Penetrator (RNEP) or nuclear bunker buster. The amendment failed. Comments on that debate were posted on the FAS website.

On Friday 22 July, Senator Kennedy introduced a similar amendment to the Defense Authorization bill. The amendment was debated that afternoon. (The vote on the amendment will probably occur Tuesday 26 July.) The transcript of the debate is here .

With the second amendment nearly identical and offered so close in time, the debate points were, unsurprisingly, by-and-large similar. Senators Kennedy, Feinstein, Reed, and Levin spoke for the amendment, that is, against the RNEP. Senators Warner, Sessions, and Allard spoke against the amendment. Opponents of the RNEP pointed out the horrendous consequences of using the weapon, the difficulty of knowing where to bomb, and the obvious countermeasure of simply digging deeper. The supporters of RNEP responded as before that these funds are simply for a study.

There were some new points and new emphasis. Opponents of the RNEP, citing the Administration’s past plans, argue that this is not simply a study. In previous years, the proposed program clearly ramped up to production and the opponents suggested that that is still the Administration’s intention. Senator Reed went into considerable detail on past budget requests and described the RNEP program as “…the study that turned out to be a stalking horse for a production program…”

The supporters of RNEP still do not confront directly the fact that no part of the proposed study will address any of the objections raised against the RNEP. All of the objections to the RNEP will still stand even if the feasibility study is 100% successful. Indeed, opponents of RNEP assume the feasibility study will be successful. A successful feasibility study will show that it is possible for a large thermonuclear warhead to penetrate a few meters into rock. There is unanimous technical agreement that these burial depths will not reduce fallout and will result in an explosion with a large above-ground blast and fireball. [The National Academy report was cited in the debate as saying that “…the earth-pentrator weapons cannot penetrate to depths required for total containment…” (Emphasis added.) This is technically true but misleading because it suggests there may be substantial but incomplete containment. At these shallow burial depths, there is essentially no containment of radioactive debris from weapons of the size being considered.]


The supporters of the RNEP either do not understand that the feasibility study is irrelevant to the objections to the RNEP or they believe the objections are not severe enough to stop consideration of the RNEP. Those who might be in the first category perhaps believe that the study will refute some of the objections. This attitude was expressed by Senator Warner both in the previous debate and again in this debate when he said, regarding a feasibility study, “Depending on the outcome, the Congress comes back in and then establishes whether the facts justify, as well as the threat situation, as well as the military needs, the next step of a program that would take some several years to evolve and produce a weapon.”

Senator Allard is most likely in the second category. As he said, “In all the testimony I have had over the past 3 years as chairman of the Strategic Subcommittee…never once has anybody, in testifying before the committee, said that there will not be any nuclear fallout.” Senator Allard goes on to say “Frankly, we should allow our weapons experts to determine if the robust nuclear earth penetrator could destroy hardened and deeply buried targets.”

Those in the second category are more realistic. The range of technical uncertainty does not include any meaningful difference in fallout and collateral damage. Even so, one could accept that the collateral effects of nuclear bunker busters are horrendous and still support their development. The current B-83, designed to explode on or above the surface, will have collateral effects as bad. If using that is acceptable, why shouldn’t an earth-penetrating version also be? The answer, of course, is that using the current B-83 is not acceptable except under the most extraordinary conditions.

There is no possible outcome of the proposed RNEP feasibility study that will even address, much less refute, the major objections to the RNEP. The question is whether we should be pursuing nuclear options that inevitably involve vastly destructive effects or not. Those who support this feasibility study have to say that they are supporting a weapon with collateral effects that are already well understood. If RNEP supporters in the first category believe some questions remain to be resolved, then they could make their position clearer by going on record as opposing future work on the RNEP unless the proposed feasibility study produces a weapon with substantially contained fallout and substantially reduced surface blast and fireball effects. Were they to do that, then in future years the laws of physics would take care of the rest.

[Senator Allard did make one technical error. He said, “We are going to be looking at the current arsenal makeup of weapons that we have to modify them to reduce collateral damage.” The reduced collateral damage argument comes about because the ground shock waves from an earth penetrator are much more strongly coupled than a surface burst of the same yield, perhaps by a factor of 20. One could, therefore, in principle replace a megaton surface burst with a 50 kiloton earth penetrator with the same underground effect and roughly one twentieth the surface effect. But no one is proposing this. The proposals are to take a megaton surface burster and convert it into a megaton penetrator, which will have twenty times the underground effect and equivalent surface effects. The relation between shock waves and range means that a factor of 20 greater coupling results in a factor of about 2.7 more range.]

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