Nuclear Materials Management and Safeguards System (NMMSS)

National Nuclear Security Administration

You are here

NNSA's Safety, Infrastructure and Operations office

Click for more about the office's missions.

The Nuclear Materials Management and Safeguards System (NMMSS) provides mission-critical data analytics, products, and services to inform and advance U.S. government policies and nuclear material accountancy related to domestic and international safeguards, nonproliferation, national security, and global commerce for peaceful uses of nuclear material.

NMMSS is the U.S. government’s official program to track movements, uses, and inventories of U.S. nuclear materials. These include domestically held source and special nuclear material and imports and exports of nuclear materials into and from the United States. NMMSS also tracks nuclear materials owned by the Department of Energy and the National Nuclear Security Administration (NNSA) for financial, materials management, and safeguards purposes.
As the State System of Accounting for and Control of Nuclear Material, NMMSS fulfills the U.S. nuclear material reporting commitments to the international community including the International Atomic Energy Agency (IAEA) under voluntary safeguards agreements, the Treaty on the Non-Proliferation of Nuclear Weapons, Nuclear Cooperation Agreements, and other bilateral and multilateral agreements. 

NMMSS is co-sponsored by the U.S. Nuclear Regulatory Commission (NRC) and managed by the NNSA Office of Nuclear Materials Integration.

Contact NMMSS at

NMMSS objectives

NMMSS’ activities directly influence the nuclear and national security of the United States. Its products and services are used by a diverse cross-section of stakeholders to support policy, programmatic, and mission decisions.

Entities within both the Executive and the Legislative branches of the U.S. government, the NRC, NNSA organizations, IAEA, and other governments, routinely receive and use NMMSS data. The timeliness and credibility of resultant insights and takeaways is crucial. Key products and services include:

  • Reconciliation of inventories for all commercial and government-owned nuclear materials. These include every aspect of the nuclear fuel cycle involving entities licensed by the NRC and nuclear operations taking place at DOE and NNSA sites.
  • Management of peaceful use obligations. The accounting for and tracking of material subject to obligations facilitate U.S. trade in nuclear material and equipment with foreign countries consistent with Agreement for Peaceful Nuclear Cooperation.
  • Tracking of imports and exports of nuclear materials. The United States plays a pivotal role in advancing the global peaceful use of nuclear energy, international transfers of nuclear materials, and transatlantic and transpacific commerce.
  • IAEA system of record for accounting and control of nuclear materials. In particular, U.S. commitments related to notification of imports and exports and application of safeguards in the United States.
  • Maintain records of all U.S. nuclear materials, including inventory, movements, production, consumption, and losses, from the 1940s to the present.
  • Unclassified updates of plutonium and highly enriched uranium declarations.
  • Outreach, awareness, and training. These include engagement and interactions with domestic stakeholders and international counterparts.
Reporting requirements and mechanisms for DOE/NNSA sites

Some DOE directives outline specific objective and metrics that the NMMSS program directly supports.

Reporting requirements and mechanisms for NRC licensees

NMMSS works closely with the U.S. NRC to fulfill the requirements for licensees. The documents below outline these pathways.

Major products and services

The import and export of nuclear materials is a tightly controlled and regulated process. It is executed through possession of the applicable NRC import/export licenses, bilateral agreements which contain the requirements on the exclusively peaceful use of transferred nuclear material, and the application of IAEA safeguards. Frequently, the imports and exports also include additional country-specific restrictions and limitations on the use and/or subsequent transfer of the material.
NMMSS fulfills the U.S. Government’s voluntary reporting commitments to the IAEA:

NMMSS also provides analytical reports to other U.S. agencies and NNSA organizations in support of Peaceful Use Nuclear Cooperative Agreements.

Upcoming training opportunities

Schedule of upcoming NMMSS classes

For registration please send your contact information (name, organization/affiliation, address, email, phone, and citizenship) to You may also contact us via email for additional program information.

December 4-6, 2018

NMMSS Newsletter

Contact us

Email You may also contact us via email for additional program information.


Q. How do I request NMMSS services?
A. The most effective way to request NMMSS services is to contact a nuclear materials analyst and ask for assistance. If you are unsure whom to call, contact any member of NMMSS’s staff and you will be directed to the person who can be the most help on the topic presented.

Q. How do I request a distribution change of standard reports?
A. Any change in standard report distribution for your office should be put in writing and forwarded to NMMSS staff. Whether a change in frequency for existing reports or the addition or deletion of a report, the analyst can modify the distribution schedule and the new distribution schedule can be put into effect immediately.

Q. How do I request a special report?
A. The most common way to request a special report is to call an analyst and discuss the need for the report. The analyst may suggest a different report if it is believed that one different from the one requested would be more suited to the need.

Q. How do I change an item of information in the Reporting Identification Symbol (RIS) Directory?
A. There are two ways to update RIS data. First, the responsible official makes pen-and-ink changes in the existing data sheet for the facility, as contained in the directory, and forwards it to NMMSS staff for revision. Second, the on-line update procedure may be used. Go here and click “NMMSS Change of Authorized Contacts Response Form.”

Q. How do I change facility authorized contact designation?
A. A change is made on a Change of Authorized Contacts response form. This form, signed by the nuclear materials representative at the facility, enables the person named to provide data changes by telephone to NMMSS analysts. Go here and click “NMMSS Change of Authorized Contacts Response Form.”

Q. How do you change report classification markings?
A. NMMSS applies report classification markings based on guidance provided by the facility. Upon receipt of facility modifications to existing guidance, NMMSS staff will incorporate the changes into the system. Any change in classification guidance should be provided to NMMSS in writing.

Q. How can I receive the newsletter: NMMSS News?
A. NMMSS publishes a newsletter and distributes it to over 1,000 users. The newsletter contains items of interest to the user community. News of upcoming training courses, conferences, and other events are highlighted. Also, the newsletter provides an excellent forum for sponsors to inform users of changes that are to be made in reporting requirements. Persons or organizations are added to the distribution list upon request. There is no charge for the newsletter.

Q. How do I fill out a DOE/NRC Form 741 document?
A. Please refer to DOE Manual 470.4-6 Nuclear Material Control and Accountability for DOE reporting. For NRC licensee reporting, refer to NUREG/BR-0006, Instructions for Completing Nuclear Materials Transaction Reports.

Q. Why should I fill out a DOE/NRC Form 741?
A. Completing the form is required by the DOE and NRC for reporting transactions in nuclear material.

Q. Should I fill out a DOE/NRC Form 741 document for all material types?
A. No, the reportable material types are listed in DOE Manual 470.4-6 and NUREG/BR-0006.

Q. Are there any documents that I should receive for reporting material?
A. Please refer to DOE Manual 470.4-6 or NUREG/BR-0006 and –0007.

Q. Sometimes the Nature of Transaction Code is referred to as the "TI" code. This is the code used to report a change in material ownership and transfers relating to enriching service agreements. What do the letters "TI" stand for?
A. "TI" means transaction indicator, a term that is seldom used today. This term is not to be confused with the Type of Inventory Change Code. The TI code is entered in the present Block 11 of the Form 741, whereas the Type of Inventory Change Code is entered in Block 26C of the form.

Q. I created errors in NMMSS when I used owner code “J” on a shipment when owner code “G” should have been used. The effect of the transaction was creating a negative balance in “J” owner code material and no change in the owner code “G” balance that was shipped. How can I correct the errors?
A. Simple. Whenever an ownership changes, report the change to NMMSS. This change is reported by a classic “A-M” transaction code. This change should be reported before the shipment of the material to another party. Otherwise, the inventory data by ownership code in NMMSS becomes incorrect. The error can be subsequently corrected, however.

Q. Are NRC licensee facilities required to report DOE-owned material?
A. NUREG/BR-0006 and –0007 provide the NRC reporting instructions for special nuclear material (plutonium, enriched uranium, and U-233) and source material (natural uranium, depleted uranium, and thorium) which apply to NRC and Agreement State licensed facilities. The NUREGs also guide licensees to DOE reporting instructions which may stipulate DOE’s reporting requirements to NMMSS for a variety of DOE or Government-owned/leased materials.

Q. May I reuse transaction numbers after a certain number of years have passed?
A. No. Do not reuse transaction numbers. Each transaction number must be unique in order for NMMSS to process transactions properly and to assure that data queries select the appropriate transaction desired.

Q. Could you clarify the meaning of the terms 91-B material and 91-C material?
A. In NMMSS reporting, 91-B material refers to material transfers to the Defense Department for users in national defense. The other category, 91-C, refers to the sale, lease, or loan to other nations of material for military applications. Understandably, only a small number of facilities report transactions in these materials to NMMSS.

Q. Is it required that I use the shipper’s batch name in 741 reporting of receipt of material from foreign facilities?
A. Yes. The IAEA performs a safeguards function called “Transit Matching” in which they match shipment data reported by the governments of both the shipper and receiver. Use of the same batch name enables them to make quick matches of shipper and receiver data. The NRC’s NUREG/BR-0006, requires the shipper and receiver to use the same batch name to facilitate IAEA transit matching.

Q. Does NMMSS office have information on old RIS codes that were used by the AEC prior to the development of the system?
A. Yes. Discuss your request with a NMMSS analyst.

Q. What are the benefits of submitting data electronically to NMMSS via the classified or unclassified direct links?
A. The benefits of submitting data to NMMSS electronically include timelier data submission, reduced chance of human input error, and paper reduction. Use of the direct links is also less expensive than most modes of submission. A final important note: if you are a licensee, electronic reporting is required by the NRC. You may also receive your reports via the direct links, greatly reducing the time involved.

Q. Why is NMMSS designed with Reporting Identification Symbol (RIS) inventory profiles for Department of Energy (DOE) facilities, thereby limiting the choices of Composition of Ending Inventory (COEI) codes an RIS can use?
A. The DOE establishes RIS inventory profiles for DOE facilities. These profiles include the type and amount of material a facility can have and the COEI codes, which are valid for the facility. If you desire a change in your facility’s profile, your Operations Office MC&A staff should submit a request for the change to the Office of Plutonium, Uranium, and Special Materials Inventory (SO-62).

Q. What are the approved electronic file formats documented for data submission to NMMSS?
A. The electronic file formats approved by both DOE and NRC are contained in NMMSS Report D-23 for DOE facilities and NMMSS Report D-24 for licensees. See NMMSS Reports below.

Q. Am I required to submit a DOE/NRC Form 741 when I ship multiple individual items where each is less than .5 of the reporting unit?
A. A transfer of multiple discrete items, which individually are less than .5 of the reporting unit and are the same material type, need to be summed to a total of that material type. If that sum is equal to or greater than .5 of the reporting unit, the quantity is rounded to the nearest whole reporting unit and a DOE/NRC Form 741 must be submitted.

Q. What composition codes (COEI) can DOE facilities use to report inventory?
A. Every DOE facility has a specific inventory profile established in the NMMSS database. Questions about individual codes should be directed to NMMSS analysts. A facility may request either NMMSS report I-17C, Inventory Profile by Facility, which shows the active COEI descriptions for a facility as represented by their reported inventory; or an I-17D, Authorized Inventory Profile by Facility, which shows the COEI descriptions authorized by DOE for use by facility.

Q. Is there a report that will show all my transaction errors for the month so I can try to improve my data?
A. Yes, the TJ-006M will show the number of transactions submitted, number of detail lines, number of errors, and what the errors were. This will allow you to see if a trend exists, show you where to improve your data, and help reduce the time spent on error correction.

Q. What are the advantages of receiving daily reports from NMMSS showing the data processing activity for my facility?
A. There are several advantages. First, daily reports allow you to verify the data sent to NMMSS was received or that you have sent all of the data you thought you sent. Occasionally, data arrives that is non-readable. Since NMMSS staff cannot determine what was sent, they will not know data is missing or misrepresented. Secondly, daily reports allow you to see your errors. This will help identify and reduce your overall error rate.

Q. Is there a fast, reliable method of sending data to NMMSS and also receiving reports on the same day NMMSS staff makes distribution?
A. NMMSS classified and unclassified direct links will provide your facility with these capabilities. If you have a computer, a modem, and a communications package, this bulletin board system will allow you to send/receive data directly to/from NMMSS from your workstation. The classified direct link requires use of a federally approved, encryption device (e.g. an AT&T 1910).

Q. If I submit a DOE/NRC Form 741 to NMMSS and realize a week later that I forgot to account for decay, leaving line 4 incorrect by 2 grams of element and 2 grams of isotope, how do I correct the data in NMMSS?
A. If the month in which the original transaction was sent is still open, then submit a replacement 741 (using processing code “C”). If the month is closed, then submit a 741 using an action code of “C” or “D” (shipper or receiver, respectively). If using an action code of “C” or “D”, the correction must back out the incorrect line using negative numbers in the Number of Items, Element Weight, Element Limit of Error, Isotope Weight, and Isotope Limit of Error fields, followed by a new line with the correct numbers. Never add a line just showing the difference.

Q. Sometimes, why do I receive what appears to be duplicate sections on the M-742 report?
A. The M-742 consists of several sections: current month, quarter to date, semiannual to date, and year to date. So that we may individualize each report to the site’s specific request, the sections you have requested will always be printed. Depending on the month, the report may contain a duplicate section. For example, in the first month of the quarter, the current month and quarter-to-date sections will be identical.

Q. How do you report natural uranium with an assay slightly greater or less than the theoretical value?
A. You may report such material as natural uranium. The gaseous diffusion plants have a range within which natural uranium is reported (for example, Portsmouth is .7100 to .7120 percent U235). This allows you to report the material as natural uranium.

Q. What is the latest time I can submit transactions and still have them processed on that date?
A. Data submissions received by NMMSS after 12:30 EST will be processed the next workday unless the facility requests an exception. Requests for exceptions should be addressed to NMMSS analysts. Exceptions will be accommodated, time permitting.

Q. May a facility that changes its RIS code start a new transfer series with number “1”, or should its first transfer number under the new RIS follow the last number used under the previous RIS code?
A. Numbering may start with “1”, but a facility may have special reasons for starting with another number. NMMSS will accept either numbering scheme.

Q. Why does NMMSS send a blank report even though my facility submitted no transactions during the reporting period?
A. NMMSS issues blank reports to inform you, DOE, NRC, and USEC that a report was indeed gathered from your facility. NMMSS attests that no report-specific data was provided. Think of it like your bank statement.