ML19338E151
| ML19338E151 | |
| Person / Time | |
|---|---|
| Site: | 07000371 |
| Issue date: | 07/15/1980 |
| From: | Kirk W UNITED NUCLEAR CORP., UNITED NUCLEAR CORP. (SUBS. OF UNC, INC.) |
| To: | Evans L NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| 16871, NUDOCS 8009240668 | |
| Download: ML19338E151 (3) | |
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UnC MAVAL PRODUCTS pot w n)
Div+on of Unded Nuc' ear Ccrpora9cn 67 Sandy Desert Road Teicrone 203/8481511 gg A unC RESOURCES C0"gany Uncasvale. Comecncut C6" 9
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July 1.5,1980 3
? l OITD - f D m Mr. L. J. Evans,Jr., Chief OA/
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Regulatory Improvements Branch
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U.S. Nuclear Regulatory Commission
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(2 Washington, D.C. 20555
Dear Mr. Evans:
Subj ect:
Safeguards Guidance Group Assistance Request-Intrusion Alam Redundancy
Reference:
License Safeguards Guidance Group Bulletin #5 The above reference makes clear the requirement that both central and secondary alam stations must have the ability to take control of all electronic security systems. Each station must be able to operate in the event the other station is destroyed or made inoperative. It must be assumed that to be made inoperative includes collusion by the guards or a takeover by intruders. This implies that the on-site Security Supervisor must not only have the ability to switch control from one alam station to the other but also the ability to mute one station.
l In order to meet all requirements it is necessary to have a remote switch which the Security Supervisor can activate. The switch itself must be installed in an inaccessible secure location. The Security Supervisor will use a coded radio transmitter to activate the switch. The attached diagram shows how the Mosler Company would propose to wire the UNC Montville facility. The switch marked "SW" is a two way switch ad when in nomal position the C. A.S. exercises control over all security electron-ic systems. The S.A.S. receives tracking signals from RUT's located in C.A.S., but has no control capability.
Should the C.A.S. operators descroy the C.A.S. electronic equipment or lock the Security Supervisor out, than the coded transmitter can be activated and the transfer switch will shift to position two.
This transfers control to the S.A.S. and disconnects all control and signal data to the C.A.S.
The entire electronic package in each alarm station has a ta=per proof feature which prevents the operators from interjecting false signals, interrupting signals or incapacitating the equipment without each station receiving an alam.
This system does not use computers and is much less complicated but more 800gg49
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- ..,p*p Mr. L.J. Evans,Jr., Chief page two July 15,1980 reliable. It gives constant status of all sensors at each alarm station, and it meets the need to place ultimatr control in the Security Supervisor.
(No computerized systen can make a judgement as to which alarm station operator has become an adversary)
Tha guidance contained in NUREG/CR-0543 paragraph 4.2 states the alann signal reaching the C.A.S. and S.A.S. must be split or divided such that each receives an independent signal which cannot be interrupted or incapacitated by the other alarm station. License safeguards guidance group bu11etin.#5 requires both C.A.S. and S.A.S. have the same control function. These two requirements indicate a control function switch must j
be installed and operated based on a human decision.
i The design function which precipitated this letter is that under normal operations the M sler system as proposed will route the tracking signals o
for the S.A.S. through the C.A.S.
(This will not reduce the tamper or t
self checking feature of the system) The control signal as well as display signals will both be switched directly to the S.A.S. should the remote function switch be activated. The C.A.S. will be denied all signals.
i This technique meets the requirements as defined in Bulletin #5 requiring both control and status signal switching even though the~ status signal is received through the C.A.S. prior to activating the switch. It is requested that this concept be approved as meeting the requirements of Bulletin #5 and NUREG/CR-0543. Your guidance is essential at this stage q,
because other alternatives are very costly and not as reliable.
For further technical information contact the Plant Engineer, John Lawrence, Ext. 427 or Security Director, Bob Gustafson, Ext. 401.
4 Sincerely, e
~'s William F. Kirk Manager, Nuclear Indusittial Safety i
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