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Introduction to MCNP6

Date:Monday October 21, 2024 through Friday October 25, 2024
Time:9:00-11:30 and 1:00-4:00 (US Mountain Time); only AM session on Friday
Place:WebEx Online Environment
Maximum Enrollment:40
Minimum Enrollment:20
Prerequisites:Class attendees are expected to have never used MCNP6 or have very little experience with it.

Other key dates:

  • August 02, 2024, non-US citizen registration deadline.
  • September 23, 2024, class go / no-go determination and refundable withdrawal deadline.
  • October 07, 2024, late-registration deadline.

See Other Details below for more information on these dates.


This introductory class forms the basis of the LANL-delivered MCNP class curriculum.

The provided examples will be assembled, executed, and examined in real time.

Time will be available to discuss individual questions and problems with MCNP experts.

If time permits, details on more advanced features in the code can be discussed at the attendees' request.

The class will be based on version 6.2 or later of the MCNP code.

Topics include:

  • New features in MCNP6
  • Input construction and basic geometry
  • Plotting of geometry
  • Source definitions
  • Tallies and plotting
  • Neutron data and photon/electron physics
  • Statistical analysis
  • Criticality
  • Variance reduction
  • Please address all correspondence regarding this class to the MCNP Registrar.

    Next Steps after Registering

    Your registration is not complete until the following documents have been submitted to the MCNP Registrar. Everyone must:

    1. Submit proof of an MCNP license.
      • For those who received access to the MCNP code from RSICC, submit either:
        • RSICC license PDF (example, preferred), or
        • RSICC request history (example). An email with this history is automatically sent to you after authenticating with the RSICC Order History webpage and verifying contact information.
      • For those who received access to the MCNP code directly from LANL: submit the fully approved software-distribution form you received when access was granted.
    2. Submit a completed MCNP class request form.
      • A frequently asked question is "Why do I have to fill out this form when I just registered?" Unfortunately, the processes that need to be followed to admit students to MCNP classes require these two sets of data to be submitted, processed, and kept separately. We apologize for the inconvenience.

    In addition, all non-US citizens must:

    1. Submit image(s) of identification document(s) in the form of either:
      • Official government identification card (acceptable for online classes), or
      • Passport name/photo pages and any applicable visa(s) (required for in-person classes) or
      • US Permanent Resident card (i.e., the USCIS I-551 form also known as a "green card"), if applicable. Submit images of front and back.
    2. Submit detailed résumé or curriculum vitae with the following details (download an example Microsoft Word document):
      • Company/school name, location (city/country), position held, and dates of employment (start and end month/year).
      • The employment and education from the time of turning 18 years old must be accounted for with no gaps.
    3. Clearly indicate all citizenships when asked about citizenship. If born in a country not listed in 10 CFR 810, then evidence of non-citizenship and/or renunciation of birth-country citizenship must be provided.

    Before the class starts, all participants:

    • Must obtain and install the MCNP6 code.
      • The executable version is sufficient for class purposes. Directions to request the code from RSICC can be found here. Note that LANL employees follow a different process to acquire access to the MCNP code.
    • Must submit registration fee promptly upon notification.

    Payment Options

    The class fee includes a collection of files with all class slides (over 600), handouts, and other reference material.

    There are four payment options, with credit card being the preferred option. Details about each method follows.

    1. Credit card (preferred)
      • Visa, MasterCard, or Discover Card are accepted for payment.
      • Please pay at: https://about.lanl.gov/lanl-resources/payments-to-the-lab and select MCNP Training from the dropdown menu.
      • Payment Description: Class title and date. If another individual will be making payment on your behalf, please have them include your name in this field.
    2. Check
      • Please make out your check (US dollars only) payable to: Los Alamos National Laboratory/UT32
      • Make sure your name appears on accompanying documentation with the check.
      • Mail the check to:
        Los Alamos National Laboratory
        P.O. Box 1663, MS P231 Los Alamos, NM 87544 USA
    3. Wire transfer
      • Please email the MCNP Registrar with a request for wire transfer bank information.
    4. Internal cost code (LANL employees must use this)
      • Please email the MCNP Registrar and provide a complete cost code and organizational code.

    Other Details

    Minimum Class Enrollment

    There is a minimum number of participants required for each class to be held. Registered class participants will receive an email no later than four weeks before the class start date (by September 23, 2024) notifying them if a class is cancelled because of low enrollment.


    If the class is cancelled because of low enrollment, participants may request a refund of any registration fees paid or may request that the fee already paid be credited towards their attendance at a future class.

    If you cannot attend the class for another reason and cancel your registration less than four weeks in advance (after September 23, 2024), we will be unable to refund any registration fee paid. However, the fee may be applied towards attendance at a future class. Alternatively, another person from your organization may attend in your place, depending on the citizenship of that individual. Contact the MCNP Registrar for further information.

    Last-minute Registrations

    Registrations received within two weeks prior to the start of a class (after October 07, 2024) may be accepted on a space-available basis and depending on the citizenship of the person registering.

    Non-US Citizens

    Registration requests for non-US citizens who are citizens of a country listed in US Regulation 10 CFR 810 are processed by the LANL Foreign Visits Office. This security approval processing is based on requirements issued from the US Department of Energy. The processing normally takes at least 60 days. You must register and provide all requested information by August 02, 2024. Although we can never guarantee that a security approval will be received, we will make every attempt to obtain an answer for your attendance request as soon as possible.

    Registration requests for non-US citizens who are citizens of or reside in a country not listed as a Generally Authorized Destination in US Regulation 10 CFR 810 cannot be processed by LANL and will be submitted directly to the Department of Energy.

    For a list of 10 CFR 810 countries, please go to the Electronic Code of Federal Regulations, 10 CFR 810.

    Pre-class Information

    Students who are fully registered and have confirmed payment for the class are ready to attend. This webpage lists the details needed to attend.

    However, prior to arrival the student must accomplish two critical steps with the computer he or she will use for the class:

    1. Install and test MCNP6.2 or MCNP6.3.
    2. Download the class materials (presentations, example input files, etc.).
      • A download link for a ZIP file containing class materials will be provided to registered and fully paid attendees the week, typically the Thursday, before the class.
      • The download is approximately 500 MB and should be fully extracted for use.

    For WebEx-based classes, WebEx connection information will be provided to registered and fully paid attendees the week, typically the Thursday, before the class.