ML20247D310
| ML20247D310 | |
| Person / Time | |
|---|---|
| Issue date: | 03/21/1989 |
| From: | Alexander Adams Office of Nuclear Reactor Regulation |
| To: | Nelson R AIR FORCE, DEPT. OF |
| References | |
| PROJECT-678A NUDOCS 8903310034 | |
| Download: ML20247D310 (4) | |
Text
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I Dr. Robert C. Nelson, Lt. Col., USAF Executive Officer, THRSSG Directorate of Nuclear Surety Kirtland Air Force Base, New Mexico 87117-5000
Dear Lt. Col. Nelson:
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SUBJECT:
COMMENTS ON THE STATIONARY NEUTRON RADIOGRAPHY SYSTEM (SNRS)
As requested in your letter of December 2,1988, please find enclosed our comments on the digital instrurnentation and control console for the SNRS which is being installed at McClellan. Air force Base in California.
Because of an open item concerning software documentation which must be provided by the control console vendor, these comments are preliminary in ncture. The Air Force will be provided our final recommendations under seperate cover in the near future.
Because your facility is not licensed by the NRC, these comments are not binding on the Air Force and no response is required.
If you have any questions concerning this review, please contact me at FTS 492-1121 or 301-492-1121.
Sincerely,
/s/
Alexander Adams, Jr., Project Manager Standardization and Non-Power Reactor Project Directorate Division of Reactor Projects - III, IV, Y and Special Projects Office of Nuclear Reactor Regulation
Enclosure:
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March 21, 1989 Dr. Robert C. Nelson, Lt. Col., USAF Executive Officer, TNRSSG Directorate of Nuclear Surety i
Kirtland Air Force Base, New Mexico 87117-5000
Dear Lt. Col. Nelson:
SUBJECT:
COMMENTSONTHESTATIONARYNEUTRONRADIOGRAPHYSYSTEM(SNRS)
As requested in your letter of December 2,1988, please find enclosed our
. comments on the digital instrumentation and control console for the SNRS which is being installed at McClellan Air force Base in California. Because of an open item concerning software documentation which must be provided by the control contole vendor, these comments are preliminary in nature. The Air Force will be provided'our final recommendations under separate cover in the near future. Because your facility is not licensed by the NRC, these comments are not binding on the Air Force and no response is required.
If you have any questions concerning this review, please contact me at FTS 492-1121 or 301-492-1121.
Sincerely, C24h
/
Alexander Adams, Jr., Praij t Manager Standardization and Non-1 r
Reactor Project Directorate Division of Reactor Projects - III, IV, Y and Special Projects Office of Nuclear Reactor Regulation
Enclosure:
As stated
4 ENCLOSURE RESPONSE TO TECHNICAL ASSISTANCE REQUEST 1
U. S. AIR FORCE McCLELLAN TRIGA By letter dated April 8, 1988 the U.S. Air Force requested NRC's review of some concerns and questions that they had about the General Atomics (GA) new digital instrumentation and control console which is proposed for installation at the McClellan Air Force Base reactor facility, the Stationary Neutron Radiography System (SNRS). The McClellan facility will be regulated by the Air Force and therefore will not be licensed by the NRC. The NRC agreed with most of the issues raised by the Directorate of Nuclear Safety (Air Force) which should be reviewed to assure safe operation.
By letter dated December 2,1988 the Air Force requested NRC's assistance and recommendations in the review of, among other issues, the GA digital instrumentation and control console. Due to upcoming licensing and 10 CFR 50.59 reviews of several NRC licensees with the same equipment, the staff agreed to do a short audit to answer the primary question from the Air Force as to whether the GA digital control console would be licensable at a NRC regulated facility.
To assist us in reviewing the SNRS we reviewed General Atomics 10 CFR 50.59 submittal, the Armed Forces Radiobiology Research Institute (AFRRI) 10 CFR 50.59 submittal, and the SNRS safety analysis report prepared by Argonne National Laboratory (dated August 1988). To familiarize ourselves with the new equipment we also visited the AFRRI facility twice. We reviewed the installation and operation logs at the AFRRI facility and reviewed the documentation involving AFRRI, GA and the digital console users group.
We found the staff at AFRRI to be knowledgeable and under many of the same operation constraints that the SNRS may be subjected too. The AFRRI facility has many differences but the digital console and the safety equipment are basically the same. The AFRRI facility uses the NM-1000 digital system only as a monitoring channel while the SNRS uses it as one of its safety trip channels.
The NRC finds that the use of the digital NM-1000 safety channel and the analog NPP-1000 safety channel provide a high level of independence and diversity.
The NRC does not require the same level of separation between control and safety systems for research reactors as it does for power reactors. Though the GA console has not been shown to meet power reactor requirements, the staff has concluded that the GA digital console is at least as good as and in several ways better than existing control consoles at NRC licensed research facilities.
The hardware used is similar to hardware which the staff has seen in use for other applications. The primary concern of the staff during the audit was the i
methodology used for software development (verification and validation).
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for power reactors the NRC uses Regulatory Guide 1.152 " Criteria for Programable Digital Computer Systems in Safety Systems of Nuclear Power Generating Stations."
Several other military specifications and European standards may be acceptable to the staff but have not been submitted for review. Application of digital technology to research reactors is relatively new and therefore a specific software. regulatory guide has not been issued. The staff believes that application of RG 1.152 is appropriate for the research reactors and recommendsthatsimilarverificationandvalidation(V&V)beperformedfor all software.
. Our audit of the General Atomics software development indicated one major shortcoming which we have asked GA to address. GA has not shown that the functional requirements for the NM-1000 have been included in the final software design and properly tested. We have requested GA to prepare what we. refer to as a functional requirements matrix. The matrix will show each l
task within the functional requirements and a specific test which demonstrates that the task has been accomplished. GA has comitted to resolve this issue and provide a submittal within a month. The staff will review this submittal and will inform the U.S. Air Force of our findings.
We note that though the staff considers the application of a thorough V&V review to be good engineering practice for all software, we only require that V&V (RG 1.152) be done for safety related systems (hM-1000). The remaining software which is not required to scram the reactor has been shown to our satisfaction not to impede the operation of the safety grade software primarily due to the use of watchdog timers, isolation devices and dedicated scram circuits.
Th0 NRC general conclusion at this time is that if GA follows through on their comitment to provide additional software documentation, and it is found acceptable then the staff would recomend a facility similar to the SNRS to be licensed.
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