High Yield Testing, October 1968 (Deleted) Companion of Document 317772)

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i , RES & D-l Nuclear Testing HIGH YIELD TESTING BEST COPY AVAILABLE This document has been reviewed by a DC/'RO and confirmed to tie UNCLASSIFIED. Name: Lani Fellows

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HIGH YIELD TESTING U DIVISION OF MILITARY APPLICATION UNITED STATES ATOMIC ENERGY COMMISSION

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RECORD OF REVISIONS AND ADDENDA Changes to this docinrient may be issued from time to time, as appropriate. These should be inserted upon receipt. Change Change Entered By Date Entered

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HIGH YIELD TESTING This document describes requirements and plans for megaton-size underground tests most of which are in support of the Anti-Ballistic Missile warhead developmen^p^f^ran^(SP^RTA!0 • The plan visualizes 15 underground testsHjjjjjjjm^^^mH through FY 1971._ Fahute Mesa (Nevada), Central Nevada and AmchitVa are planned as test sites. Provided the scheduled events are permitted to take place as planned, the present construction program is adequate. 2 High Yield Test Programs ........ ........................... 4 2.1 Initial Test Plan ...................................... 5 2.2 SPARTAN Test Program .............. ..................... 5 2.3 Advance Systems Development Test Program.... .......... 9 3.2 Emplacement Hole Specifications.... ................... 13 3.3 Special Construction Techniques ....................... 13 3.4 Combined High Yield Test Program...................... 14 4.2.1 High Yield Insurance Holes at Central Nevada .... 18 4.2.2 High Yield Construction Shift from Amchitka to ... 4.2.3 Shift High Yield Construction from Pahute Mesa to Central Nevada ...r......................... 19 1 High Yield Weapon Developments ...... 1.1 SPARTAN Warhead Yield Requirement 1.2 SPARTAN Design Concept ......... 1.3 Advanced Warhead Concepts ......

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requirement is in direct support ci the SPARTAN program. Require- y W/ meats for* testing other high yield devices may be forthcoming in 1.1 SPARTAK Uarhead Yield Requirement To meet.the currently planned October 1972, the warhead will have to be tested and veaponized on a schedule that will permit the first pro duction units to be available by January 1972.

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1.3 Advanced Warhead Concepts While the DOD has not expressed formal requirements for high yield warheads in addition to the current SPARTAN warhead, LRL and LASL are also studying advanced warhead concepts whichhave potential for future applications in the high yield range. Some or all of the following DOD systems could result in firm high yield requirements being placed on the AEG: follow-on SPARTAN, Sea Based Ballistic Mi These system possibilities necessitate long-range planning of sufficient tests to provide data on the feasibility of warhead LRL and LASL are engaged in extensive calculations! efforts to investigate new applications of physics principles which would result in nuclear devices to meet the above potential requirements as well as to suggest, in accordance with responsibilities assigned by Congress to the AEG, nuclear devices applicable to entirely new areas of weapon technology. Essential device test programs have aireach been planned to match these programs— see Section 2.3. Additional tests may, of course, be required as the calculational efforts progress and the results of earlier tests become available.

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Somd of the physics concepts which ere being investigated potential application in both strategic offensive and defensive warheads. 2 High Yield Test Programs doe archives While, ideally, one v/ould like to state a set sequence of tests that would be needed in the development of a specific large yield weapon design, it is actually extremely difficult to forecast with much accuracy the tests that will be required in an individual development program. Furthermore, since the limited test ban treaty prevents testing in the atmosphere, we must structure test programs in such a manner that test objectives can be met with underground testing only. For a particular weapon design each successive test, through its results, may influence to some degree the nature of related tests that are to follow. This degree of uncertainty should be recognized in regard to high yield test forecasts. The tables within this section show first the SPARTAN tests as they were originally forecast and then project the other, high yield test programs as they are presently

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2.1 Initial Test Plan The high yield test program, as it vas envisioned in mid 1S66 and as it; was presented to the President in December 1966, stated the requirement for four large yield shots at Amchitka and two large yield shots at Central Nevada plus site calibration/proof shots at each of the test location^ rre was the requirement for several tests; considered within an acceptable level for PaliuteTlesa and not requiring tests at a supplemental Aite*_ been modified to provide for three Irange at Central Nevada and three events _____lat* Amchitka. One of the tvyo aiit^hprized develop ment/calibration events at Central Nevada and the second hqs been cancelled. y SPART-Vrl Test Schedule OOE ARCHIVES The requirement to test underground, as imposed by the limited hese tests must be arranged within a tight test schedule to facilitate meeting the SPARTAN IOC, and necessarily, the tests must be accomplished within reasonable fiscal limits. The resultant test program consists of several series of tests designed^ to obtain the maximum dat>a for the least possible cost consistent with other limitations. The SPARTAN test program has evolved with the ollowins identifiable test categories

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_________________ ('•■'hile soiae of the Iovj yield tests are iientioned herein in conjunction with the SPARTAK test, program so as to give a complete picture of that program, the lower yield t_ests- wnich can bs fired at KTS without problem are not directly the subject of this paper.) The SPARTAN development program now calls for the following Event Description Notes:

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The following areas are used for the high yield test program. 3.1.1 Pahute Mesa DOE ARC*1’fTTBased on test experience at Pahute Mesa and considering the area's geology and remoteness, that site is probably suitable for the tests in the !• to 2 OT yield range \-;ithcreation of significant. there was no observed damage to structures. In the Pahute Kesp part.of the Nevada Test Site the underground mediui?. is fairly competent rod; with downhole temperatures sufficiently low that miners can work to mine chambers; Hydrology tests indicate no problems with transport of radioactive debris in ground vjater. From the standpoint of containment and hydrology, Pahute Kesa is considered acceptable for low megaton tests. From the standpoint of public reaction, the Pahute Hesa area may be more yield limited than has been expected. The public concern is directed at various conceivable side effects of underground tests including radioactive release, contamination of ground water, seismic damage to structures and damage due to triggered earthquakes. (Recently reported data on aftershocks following our larger yield events may lead to increased public fear over earthquake triggering.) The AEG v;as made particularly aware of public attitude regarding high yield testing at Pahute Mesa by the BOXCAR event in April 1968. For the present, the AEG plans a very gradual yield escalation at Pahute Mesa with the design/

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Based on the results of the FAULTLESS event which was January 19, 1968, at a yield of about Central Nevada area, including parts of ■lot Creek 'Talley, Pancake Range and Little Smokeju. ^^He^^yy^^^^r^tically acceptable as the site with a possibility for even higher yield events in the future. Studies of underground hydrology are still in progress. On the basis of the informal results presently available, hydrology experts have .estimated that radioactive contaminants will remain within a few miles of the firing points while being reduced to the maximum permissible concentration or lower, so that public safety can be adequately protected in these localised areas. Unfortunately, the underground temperatures at drill locations in Hot Creek Valley are so high that the mining of chambers is not feasible. However, the dmmhole temperatures in one exploratory drill hole in nearby Little Smokey Valley are lower and may prove acceptable for mining. DOE ARCH! V Of major concern is the possibility of seismic damage to structures at Tonopah, Nevada, and other nearby small towns as well as to high-rise buildings in Las Vegas and Salt Lake City. The critical ground motions in Las Vegas are at those frequencies at which the highrise buildings are resonant. Predictions based on BOXCAR. at: Che ^ Nevada STS based solely on technical safety considerations. However, based on seismic predictions, this yield could damage close-in structures and could cause minor nonstructural damage to particularly susceptible high-rise buildings in Las Vegas. Th^^aoj^f^his damage might be as high as $.5M to but it could be lower or even negligible. It should be recognized^ that events in the past at Pahute Mesa with yields less than BOXCAR have caused relative motions and consequent effects on high-rise buildings in Las Vegas which might be construed as minor architectural damage. This damage, while insignificant in terms of dollars or hazard to the buildings, if claimed, could be potentially serious in terms of public reaction against high yield tests. While we would not expect significant

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damage to communities such as Tonopah (about 65 miles), Ely (about 90 miles), Austin (about 85 miles) , Eureka would need to anticipate numerous and valid claims for relatively minor damage from these communities and for major damage to a few structures, mines and facilities at closer distances. A public relations program is planned to reach people in California, Nevada and Utah prior to the next high yield test in Central Nevada. With the planned public relations program, it is believed that public apprehensions will largely be overcome. On the basis of available data and experience, experts Id be acceptable for the area appears hydrologically acceptable with tight, competent rock in the exploratory holes at the depths under consideration for our tests. Underground temperatures are suitable for mining operations, if required. While Amchitka is remote and has acceptable physical characteristics, there has been a small amount of public reaction to our use of this site since it is a well known wildlife refuge with a considerable sea otter population. To overcome these reactions, the AEG has cooperated with the Interior Department in a program to minimize the effect of AEC activities on the island^ flora and fauna. Since Amchitka is surrounded by international waters, complete radioactive containment is even more urgent there than at NTS. Although the possibility of venting from an Amchitka shot is small, even a minor radioactivity escape could probably be detected by a foreign power so as to be the reason for a claim that there had been a treaty violation. The site is thus susceptible to being shut down because of international political pressures having to do with the existing limited test ban treaty or with a comprehensive test ban treaty.

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3.2 Emplacegeni: Hole Sped Cleat ions All high yield tests require emplacement'holes in competent rock media at sufficient depth to insure containment. Some high To provide the necessary cavities, v;e will rely either on the use of nine-foot diameter prefabricated steel chambers CLoplaced at the bottom of holes, or possibly, on larger underreamed chambers (greater than 20 feet in diameter) if this technique proves feasible. It is also planned to construct at least one underground chamber of standard Pahute dimensions (30* high and 15* diameter) at Amchitka by conventional mining methods. From the experimental point of view, the larger diameters xjhich may be attainable through mining or underreaming techniques are substantially preferable to the smaller maximum diameters which the steel chambers would afford. Physics calculations or experimental results might shew that the steel bulbs are too small, in which case the underreamed or mined chambers could become a necessity. The feasibility of constructing chambers by each of the available « techniques is summarized as follows: 3.3.1 A chamber, constructed by conventional mining techniques * at the bottom .of an emplacement hole, is-both costly and time consuming and involves some hazard to construction personnel. In the Central Nevada area, high rock temper atures (more than 160°F) would preclude conventional mining at sites explored to date, with the possible exception of one site now under study where temperatures are around 120oF at working depth. In Amchitka, it appears feasible to construct a chamber of at least Pahute dimensions (i.e., 15* x 30* cylinder), with the possibility of larger and more complex underground facilities, if needed. It is presently estimated that the mining of a Pahute size chamber would take about 15 months. 3.3.2 The technique of underreeming holes with special under reamer bits has been demonstrated at smaller diameters but has not yet been proved for work below the x/ater table nor for chamber diameters of up to 20 feet. Research and development effort on an underreamer tool is now underway. If it is proved feasible at these diameters, and if a method

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for lining the chamber can be developed, underreaming will facilitate construction of chambers and should reduce both time and cost requirements* Present plans ' include provisions for uncerreaming if that technique proves feasible*' Uaderreaming and finishing a chamber 3.3.3 The prospect of forming a chamber by attaching a steel vessel of about nine-foot diameter to the bottom of the emplacement hole casing appears entirely feasible. This technique necessitates the drilling of an emplacement hole at a larger diameter than would be required to accommodate the hole casing, and sufficiently large to pass a steel bulb which x?ill ultimately house the device package. Current plans include previsions for underreaming two holes at Central Nevada and for raining one chamber at the bottom of a &,000-foot hole at Amchitka, but in each case a bulb would be used if the other techniques 3.3.4 AEC and DOD are currently examining a possible one-time requirement for constructing a very extensive mined complex of chambers and drifts on the bottom of one ox an experiment would take about two years and would cost about $50M, while the experiment would cost about $2CM additional. Clearly the requirement'for the complex mined chamber must be carefully studied before there is a decision to go ahead with such a costly project. 3.4 Combined High Yield Test Program DOE ARCHIVE ^ As discussed in Section 2, there are the following high yield test requirements in case all presently planned events are fired:

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However, in anticipation of a“reasonable number of TSTTures 'for tests scheduled in paragraph 2 above, accor-irnodating the indicated backup program and providing for a small number of advanced development tests, the_s^e^_i,i:ieQ_high during the period froa 1969 through Ftf will W"at^yicIds now believed technically acceptable for Pahute Mesa, and will be accommodated by the construction program at Pahute Mesa, For the same FY 1969 - FY 1971 period, the STS cons traction^program.assures testing up to three devices in the otherwise require a hole at is summarized in Table VII, Central Nevada,, The combined program

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4.1.1 Pahute and Central Nevada Test Acceptance As shown above, nine tests arc being planned toxu^ stanGpoiTi^^^^3^^o^^n.e a r Xo wh a t de gr ee the se tests "at Pahute Hesa would provide anuaunition for the use of organi2aticns opposing high yield testing near Las Vegas and could bring renewed pressure from these opposition groups directed at high Washington levels. Experience from atmospheric testing leads to the belief that, except for these groups. Las Vegas would accept minor damage without a great public outcry. To date, there is no indi cation that the anti-testing activities in the recent …