ML14288A653
ML14288A653 | |
Person / Time | |
---|---|
Issue date: | 07/27/2015 |
From: | Richard Jervey NRC/RES/DE/RGDB |
To: | |
Jervey R | |
Shared Package | |
ML14288A601 | List: |
References | |
RG 5.27, Rev. 1 DG-5038 | |
Download: ML14288A653 (6) | |
Text
Response to Public Comments on Draft Regulatory Guide (DG)-5038 Special Nuclear Material Doorway Monitors (Revision 1 of Regulatory Guide (RG) 5.27)
A notice that Draft Regulatory Guide, DG-5038 (Proposed Revision 1 of RG 5.27) was published for comment in the Federal Register March 21, Comment [ASG1]: make sure to revise responses 2014 on page 79 FR 16832. The public comment period ended April 25, 2014. Comments were received from the organizations listed below. including revised to text to conform to revised RG, some of which are the subject of OGC comments.
The NRC has combined the comments and NRC staff disposition in the following table.
Comment [ASG2]: in several places, I removed the term proposed before revision since this is a Comments were received from the following: final RG, and these revisions are therefore not mere proposals.
Andrew N. Mauer, Sr,. Project Manager, Charles A. England, Manager, Fuel and Materials Safety Licensing & Safety Analysis.
Nuclear Energy Institute (NEI) Babcock & Wilcox Nuclear Operations Group, Inc. -
1201 F Street NW, Suite 1100 Lynchburg Washington DC 20004 P.O. Box 785, Lynchburg VA 24505-0785 ADAMS Accession No. ML14119A436 ADAMS Accession No. ML14129A435
[Mr. Mauers and Mr. Englands comments were the same.]
Commenter Section of Specific Comments NRC Resolution DG-5038 Mauer/England Section C. The draft guidance states that: "Metal detectors should be The NRC staff agrees with the comment in part.
Staff used in conjunction with an SNM doorway monitor as an Accepted with modification. The following Regulatory SNM detection system and can be one of the two required changes have been made to the guide:
Guidance separate searches for concealed SNM (10 CFR
- 1. 73.46(d)(9)). The metal detector unit should be installed ...Entry/Exit Control of Personnel Access to Considerations in the pedestrian passageway as described in Regulatory Protected Areas, Vital Areas, and Material Access for SNM Guide 5.7, "Entry/Exit Control of Personnel Access to Areas" (Ref. 6) with the SNM monitor in such a Doorway Protected Areas, Vital Areas, and Material Access Areas" way that objects cannot be passed over, around, or Monitors (Ref 6) with the SNM monitor in such a way that objects under the detection area unless the equipment is 1(a.)(1) cannot be passed over, around, or under the detection under the direct and continuous observation of area. " security personnel during the entire monitoring o We recommend modifying the italicized portion of the process of an individual, package or other item. The sentence above to read as follows: entire process begins when the individual, package,
"...Entry/Exit Control of Personnel Access to Protected or other item approaches the monitoring area and Areas, Vital Areas, and Material Access Areas" (Ref. 6) ends when the individual, package or other item is with the SNM monitor in such a way that objects cannot exiting the monitoring area after the completion of a be passed over, around, or under the detection area unless monitoring event.
November 2014
Commenter Section of Specific Comments NRC Resolution DG-5038 the equipment is under the direct observation of security personnel." NOTE from NRC staff:
- The revised wording meets the intent of ensuring that Direct observation should be continuous in order to objects do not bypass the search process while providing maintain a high probability of visual detection of a the necessary flexibility in determining how to meet that bypass activity. Because a person approaching the intent. monitoring area could toss special nuclear material (in some cases -based upon the physical configuration of the area) over the monitoring area for retrieval at a later time, if not precluded to do so, the direct continuous observation should begin at that phase (i.e.,when an individual is approaching the monitoring area) of the monitoring process.
Mauer/England 1(a.)(2) The draft guidance states that: "Alarm actuation for The NRC staff agrees with the comment in part.
detectable metal mass should be 100 grams or the amount necessary to shield SNM that would allow a protracted theft The guidance correctly sets the criteria for a of a formula quantity of strategic SNM to occur before the performance-based approach to detect a protracted inventory process identifies it as missing, whichever is the theft amount of SNM. If a different criteria is lesser mass. The minimum mass of metal to undergo testing utilized than that described in the guidance , then a should be constructed into the configuration that optimizes technical basis for that criteria should be available.
SNM shielding capability and minimizes metal detection The guidance is revised as follows:
capability."
We recommend adding "or the metal mass amount as Alarm actuation for detectable metal mass should described in a licensee's NRC approved Physical Protection be the amount necessary to shield SNM that would Plan" and deleting "whichever is the lesser mass." The allow a protracted theft of a formula quantity of revised sentence would read: "Alarm actuation for strategic SNM to occur before the inventory process detectable metal mass should be 100 grams or the amount identifies it as missing, or the metal mass amount necessary to shield SNM that would allow a protracted theft that is described.
of a formula quantity of strategic SNM to occur before the inventory process identifies it as missing, or the metal mass amount as described in a licensee's NRC approved Physical Protection Plan."
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Commenter Section of Specific Comments NRC Resolution DG-5038 Mauer/England 1(a.)(4) (4) Power, sensitivity, and other controls of the doorway The NRC staff agrees with the comment in part.
monitor and metal detector should be tamper-safe when The guidance is revised as follows:
unattended.
- Licensee recommends adding Doorway monitors and Power, sensitivity, and other controls of the metal detectors secured behind locked and alarmed doors doorway monitor and metal detector should be when unattended are not required to have an individual tamper-safe when unattended. Doorway monitors tamper indicating device."
- The revised wording meets the and metal detectors that are secured behind locked intent of preventing tampering with the search equipment and alarmed doors when unattended is an while providing the Licensee the maximum flexibility in acceptable alternative measure to implementing determining how to meet that intent. tamper- safe devices on the SNM monitoring system.
Mauer/England 1(a.)(5) (5) Metal and SNM detection equipment should be The NRC staff agrees with the comment. Therefore, provided with uninterruptible power sources. the guidance is revised as follows:
Licensee recommends adding "and/or emergency generator power." Metal and SNM detection equipment should be provided with uninterruptible power sources and/or emergency generator power.
Mauer/England 1(a.)(6) The draft guidance states: "Signal lines connecting alarm The comment has been considered, and to provide relays to the alarm monitors for both metal and SNM flexibility, the statement was modified to: "Signal detectors should be supervised electronically." lines connecting alarm relays to the alarm monitors o We recommend modifying the wording to add the for both metal and SNM detectors should be following: "unless located in areas that are manned by supervised electronically or by direct surveillance to qualified security officers and only produce local alarms." detect tampering."
The revised sentence would read: "Signal lines connecting alarm relays to the alarm monitors for both metal and SNM detectors should be supervised electronically, unless located in areas that are manned by qualified security officers and only produce local alarms."
The revised wording provides the necessary flexibility in meeting the intent of preventing undetected tampering.
Mauer/England 1(a.)(9)(b) The draft guidance states: "Uranium-235. A doorway The NRC staff agrees with the comment in part.
monitor used to detect uranium-235 (U-235) should be Accepted with modification. Guidance revised as 3
Commenter Section of Specific Comments NRC Resolution DG-5038 capable of detecting highly enriched (i.e., 20 percent or follows:
more) uranium containing at least 93 percent U-235 and less than 0.23 percent impurities. The form of the material Uranium-235. A doorway monitor used to detect should be a metallic sphere or cube. Encapsulation should uranium-235 (U-235) should be capable of be tin plastic or thin aluminum (__<0.32 cm thickness) to detecting highly enriched (i.e., 20 percent or more) minimize unnecessary radiation absorption in the uranium containing at least 93 percent U-235 and encapsulation. The source should be encased in a minimum less than 0.23 percent impurities applied in such of 3 mm brass and detected at a 50 percent probability of manner that it minimizes unnecessary radiation detection with a 95 percent confidence limit. The false absorption in the encapsulation. The source should alarm rate should be less than 0.1 percent." be encased in a minimum of 3 mm brass and o We recommend the guidance be less restrictive on the detected at a 50 percent probability of detection form of the material and encapsulation than currently with a 95 percent confidence limit. The false alarm written. We recommend removing the italicized sentence rate should be less than 0.1 percent.
above.
Mauer/England 2. Operations This section calls for the doorway monitor system to The NRC staff agrees with the comment.
with Doorway automatically adjust the "alarm threshold" due to measured and Hand-held background radiation. This wording implies that the Original text:
Monitors monitor automatically adjusts its alarm setpoint based on During use, the doorway monitor system should 2(c.) background radiation. check the radiation background and reset the alarm A more acceptable wording would be to require the unit to threshold of detected radiation at least every 15 measure and compensate for background every 15 minutes minutes.
since the compensation is not normally an adjustment of the alarm setpoint (i.e., threshold) but rather an adjustment of Modified text:
the measurement offset. In other words, the monitor should During use, the doorway monitor system should alarm when a specific measured activity is detected above a check the radiation background and reset the alarm reference value, which is typically based on the background threshold of detected radiation and adjust the radiation level to which the monitor is exposed. The measurement offset at least every 15 minutes.
reference value can be adjusted based on background radiation, but not the alarm setpoint.
Mauer/England 2(d.) The intent of the requirement for doorway monitors to be The NRC staff agrees with the comment in part.
attended by two armed guards at an MAA is not clear. The Accepted with modification. Revised as follows:
NRC should clarify that it is acceptable for one guard to operate the monitor while one remains within the protective An SNM monitoring system shall be attended by 4
Commenter Section of Specific Comments NRC Resolution DG-5038 booth. two armed guards at an MAA (10 CFR 73.46 (d)(9)) within a facility containing a formula quantity of strategic SNM. The two armed guards may consist of a guard manning the SNM monitoring system and the other providing oversight of the SNM monitoring system activities by residing in an adjacent protective enclosure.
Doorway monitors should be attended at non-power reactors.
Mauer/England 2(f.) The draft guidance states: "With the individual in the The NRC staff agrees with the comment. Second doorway monitor detection area, an alarm should audibly sentence will be removed.
and visually announce in the vicinity of the monitor if the activity in the detection area exceeds the set alarm threshold Modified text is as follows:
for radiation, possibly indicating the presence of SNM. At a With the individual in the doorway monitor facility containing a formula quantity of strategic SNM, the detection area, an alarm should audibly and visually alarm shall also announce in the primary and secondary announce in the vicinity of the monitor if the alarm stations, and at least one other alarm station (10 CFR activity in the detection area exceeds the set alarm 73.46(e) (5))." threshold for radiation, possibly indicating the
- The proposed language appears to exceed the requirement presence of SNM.
in 10 CFR 73.46(e) (5), which states that "All alarms required pursuant to this section shall annunciate in a continuously manned central alarm station located within the protected area and in at least one other independent continuously manned onsite station not necessarily within the protected area, so that a single act cannot remove the capability of calling for assistance or responding to an alarm." This provision does not address three alarm stations as is implied by the current draft regulatory guide.
- The language in the draft regulatory guide implies that these doorway monitors report alarms to the CAS, SAS, and a third independent location, which is inconsistent with the referenced regulations. Since the monitors must be manned continuously by two armed guards, local alarms are 5
Commenter Section of Specific Comments NRC Resolution DG-5038 sufficient.
Mauer/England 2(g.) If it responds to the source in the anticipated manner, it The NRC staff agrees with the comment. Revised as should be concluded that the doorway monitor should be follows:
investigated, repaired if necessary, and recalibrated before reentry into service. If it responds to the source in the anticipated o We recommend modifying the above sentence as follows, manner, it should be concluded that the doorway
"... if it responds to the source in the anticipated manner, it monitor should be tested, repaired if necessary, and should be concluded that the doorway monitor should be retested before returning into service.
tested, repaired if necessary, and retested before reentry into service."
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