Researched by a Citizen Question 18

DEC 20 1968

R. E. Hollingsworth General Manager


In recognition of the vital role LASL plays in the conduct of the nuclear weapons research and development program and since the experiments performed in the Omega West Reactor are an integral part of the total LASL weapon program, we believe that in the interest of national security an interim waiver should be granted to permit continued operation of the OMR.

As a result of an earlier headquarters' appraisal of the Reactor Safety Program, AECM 8401 at the Albuquerque Operations Office, the Director, Division of Operational Safety, advised that the Omega West Reactor (OWR) at LASL apparently fails to satisfy the radioactive effluent safety criteria established in 10 CFR 100 in the event of occurrence of the hypothetical reactor acci dent as now described in the "hazard summary" for the reactor. The "hazard summary" was prepared in 1954 and is described in Los Alamos Report LA-3116. Under that earlier criteria for preparing "hazard summaries", the hypothetical accident defined f or the OWR is a "maximum conceivable accident" as opposed to the "maximum credible accident" now used in reactor safety analyses.

A meeting of representatives of DOS, DRL, ALO, LASL, and DMA was held in October 1968 to review the OWR situation and consider revised engineering data affecting conclusions as to the safety of the OWR. It was the engineering Judgment of those present that a formal analysis based upon the newly defined "design basis accident" ~ a new safety Analysis Report will likely indicate that the OWR meets present AEC safety standards. Dr. Biles' memorandum to me of October 11, 1968, which summa-rises the conclusions of the October 8 meeting and also provides the DOS recommendations for resolving the OWR status, is enclosed.

Consistent with the foregoing, it is requested that the General Manager grant an interim waiver to permit continuation of operation of the OWR based upon:

1.A national security requirement to operate the reactor.

2.The fact that preliminary engineering opinion suggests that a revised approach to the "design basis accident" will ulti mately assure that there is me undue risk.

The scope of the interim waiver will be limited as follows:

1.The OWR should be allowed to continue to operate at 8 Mw, even though it has net been officially demonstrated to be within 10 CFR 100 in the event of the originally hypothesized "design basis accident".

2.The waiver shall be in effect only until an acceptable new safety analysis has been prepared and reviewed by DOS and DRL, or until November 1. 1969, whichever occurs first.

3.The waiver shall be cancelled if at some stage in the review process definite evidence arises to indicate that the OWR will not operate with reasonable assurance of no undue risk to public health and safety.

Enclosure 2 is a more detailed discussion of the relationship between work accomplished in the OWR and the LASL nuclear weapons research and development program.

The Division of Operational Safety concurs in this memorandum and in the request for interim waiver. If you approve the waiver, subject to the conditions stated herein, please so indicate by signature below.

(signed) Edward B. Giller

Edward B. Giller
Major General, USAF
Assistant General Manager for Military Application

1. Memo fm Dr. Riles dtd 10/ll/68
2. Requrement For Continued Operation of the OWR

APPROVED:. E. J. Block General Manager
Date:DEC 23 1968


GFHedrick/dg EBGiller

so&2cc: GM v/encls.
cc: DRLw/encls.
cc: DOSw/encls.
5cc: Std. DMA


The Los Alamos Scientific Laboratory plays a vital role in the conduct of the nuclear weapons research and development program and the experiments performed in the OMEGA WEST REACTOR (OWR) are an integral part of the total LASL weapons program. Therefore, in the interest of national security, it is recommended that a temporary waiver of the provisions of 10 CFR 100 be granted and the OWR be permitted to operate at the 8 megawatt level until an updated Safety Analysis Report has been prepared and reviewed.

The 8 megawatt OWR supports a variety of LASL programs by providing sample irradiations, a neutron source for external neutron bean experiments, and facilities for in-core irradiation of instrumented capsules, fission counting for weapon diagnostics, and neutron radiography. During the past five years, members of 40 laboratory groups representing 10 of LASL's 13 divisions have utilized the OWR's experimental facilities. Another research reactor at LASL, the 25 kilowatt water boiler SUPO, provides a neutron flux much too low for most of the experiments conducted in the OWR. A reduction in OWR power sufficient to have a significant effect on the amount of radionuclides vented to the atmosphere in any hypothetical accident would result in a flux too low to be useful to most of the current projects. The nearest reactor facility which might provide support to LASL if the OWR were shut down for a prolonged period is Sandia Corporation's SER at Albuquerque. However, the SER lacks appropriate facilities for most LASL projects. In fact, Sandia regularly uses the OWR for irradiations which cannot fit into the Sandia reactor. Going further afield would be impractical for personnel permanently assigned to Los Alamos to pursue their programs effectively.

Among the experiments conducted in the OWR, those listed below are considered to be of particular importance to the weapons program:

1.Irradiation of samples to support weapons diagnostics. For calibration of gamma spectral shapes and for fission chamber calibration of debris samples recovered from underground tests, a large number of irradiations are conducted in the OWR. These experiments are essential to diagnose results of LASL's nuclear tests. Additional experiments involve neutron activation to determine trace constituents of Nevada and Amchitka soil to solve other weapons test problems.

2.Irradiation of explosives. Research on radiation effects on explosives is conducted in the OWR. These studies are necessary to evolve less vulnerable explosives systems for future warheads which will be hardened against enemy countermeasures. Relatively high energy depositions in the explosive samples may be obtained in a rather short time by exposure to the OWR flux.

3.Neutron radiography. Neutron radiographs of a variety of components, such as nitrogen valves, bellows, and high explosives, are made routinely in the OWR to assist in systems design. Neutron radiography assists design of collimators, which in turn are essential to a number of different experiments including nuclear tests. Research and development on detector systems, electron-neutron imaging systems, and on response of various film/foil combinations to incident neutron beams contribute to LASL's overall weapons design and experimental effort.

4. Production of radioisotopes. The OWR provides a convenient in-house service of radioisotopes production that enables a variety of LASL programs to proceed on an orderly basis without delays to seek tracer sources elsewhere. Some of the radioisotopes have short half-lives and could not be readily procured off-site.

5.Physics Studies. A large number of physics experiments which cannot be assigned to any particular weapons design or diagnostics program are conducted in the OWR. These experiments permit LASL scientists to expand the broad base of nuclear technology that is essential to support a viable weapons laboratory. Taking a long term view, these experiments are probably more important to the weapons program than are those which can now be attributed to specific design efforts because they enhance the physicist's understanding of fundamental nuclear structure and behavior. A few such experiments currently being conducted in the OWR are cited below:

a.Two neutron diffractometers at the OWR are used to investigate magnetic structures and transitions in rare-earth compounds at cryogenic temperatures, determine crystal structure, measure coherent scattering cross sections, and study high-temperature crystallography and phase transitions of refractory compounds .



(Contract W.7405-ENG-36)
P. 0. Box 1663
Los Alamos, New Mexico 87544
March 4, 1970

Major General E. B. Giller, USAF
Assistant General Manager for
Military Application
U. S. Atomic Energy Commission
Washington, D. C. 20545

Dear General Giller :

On November 26, 1969, a copy of "The Application of Risk Allocation to Reactor Siting and Design" was sent to Dr. M. M. Mann of the AEC Office of Regulation. This study is the UCLA Ph.D. thesis of Harry Otway of LASL and is currently in editorial process prior to being published as LA-4316.

As you will recall, the Omega West Reactor was under Washington scrutiny at about the same time, and we thought that the evaluation of the OWR by Mr. Otway's risk analysis report might be of interest, even if not persuasive, to the DRL and DOS. Attached, for your information and further distribution, if you so wish, is one copy of an abstract of his analysis. The final report will be sent you upon completion.

Sincerely yours,

Jane H. Hall
Assistant Director


Please note that this is a scanned document and is not the original nor a photocopy of the original


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