ML112850806
| ML112850806 | |
| Person / Time | |
|---|---|
| Issue date: | 10/10/2011 |
| From: | Office of Nuclear Security and Incident Response |
| To: | Nuclear Energy Institute |
| Johnson Don A. NSIR/DPR, 301-415-4040 | |
| References | |
| Download: ML112850806 (4) | |
Text
EAL Frequently Asked Questions (EALFAQ)
Request Form (Requestor to Complete)
Licensee:
Licensee
Contact:
NRC
Contact:
Is this a request for a Site-Specific EPFAQ or a Generic EPFA ?
Potentially relevant existing EALF AQ numbers: I This question involves:
(check all that apply)
NEI 99-01 EAL [;jiI, NESP-007 EALs 0, NUREG 0654 EALs 0, Other D Description of Question:
Pro osed Solution:
Note: Requestor to complete page 1 of the form and transmit through approved electronic means or mail to apn@nei.orgorNEI Emergency Preparedness FAQ, 1776 I St. NW, Suite 400, Washington, DC 20006-3708. Alternatively, the form and supporting documentation may be hand delivered to the NEI EPFAQ Coordinator. The question will be discussed at the next regularly scheduled EP Issue Panel meeting.
Form 10-04-05 Page 1 of [i]
EAL Frequently Asked Questions (EALFAQ)
Request Form EPFAQ Evaluation and Resolution Section Issue presented at Joint NRC/NEI EP Issue Panel: Date Resolution of EPFAQ I (NRC EPD Director)
Approved by:
Date:
(Industry EP Issue Panel Chairman)
Approved by:
Date:
[EPFAQ closed in tracking system and EPFAQ data~b_a....;s_e_u.....
p_da,--t_e_d.,--*_D...;..ate:
Form 10~04-05 Page 2 of [IJ
The following is in Reference to NEI 99-01 Rev 05 -----
QUESTION:
Is there a Loss of CNMT with RCS exiting uncontrollably directly to the Atmosphere through an interfacing System (Nuclear Cooling Water).
The following questions in regards to NEI 99-01 Rev 05 outline this point:
- 1. Why is a Steam Generator Tube Rupture with a Primary to Secondary leak rate of greater than 10 GPM and an Unisolable steam release from the affected Steam Generator is a LOSS of Containment Barrier and a 40 160 GPM RCS leak through an Unisolable Interfacing (NC) System to Atmosphere is NOT a LOSS of Containment Barrier.
- 2. Why if a CNMT Purge was in process, a LOCA occurred and Purge could not be isolated it would be a LOSS of CNMT ISAE and a 40-160 GPM RCS leak through an Unisolable Interfacing (NC) System to Atmosphere is NOT a LOSS of Containment Barrier..
- 3. Why in NEI 99-01 Rev 04 on page 5-F-17 does it state......
Containment Isolation Valve Status after Containment Isolation This EAL is intended to address incomplete containment isolation that allows direct release to the environment. It represents a loss of the containment barrier.
The use of the modifier "direct" in defining the release path discriminates against release paths through interfacing liquid systems. The existence of an in-line charcoal filter does not make a release path indirect since the 'filter is not effective at removing fission noble gases. Typical filters have an efficiency of 95 99% removal of iodine. Given the magnitude of the core inventory of iodine, significant releases could still occur. In addition, since the fission product release would be driven by boiling in the reactor vessel, the high humidity in the release stream can be expected to render the filters ineffective in a short period. There is no "Potential Loss" EAL associated with this item.
Why NEI 99-01 Rev 05 deleted/modified the above underlined sentence is not clear, since if there is No Loss and per the last sentence of the paragraph there is "No Potential Loss" what's the purpose and why even have the paragraph?
- 4. Why does NEI 99-01 Rev 4 and 5 state:
The existence of an in-line charcoal filter does not make a release path indirect since the filter is not effective at removing fission noble gases. Typical filters have an efficiency of 95-99% removal of iodine. Given the magnitude of the core inventory of iodine, significant releases could still occur. In addition, since the fission product release would be driven by boiling in the reactor vessel, the high humidity in the release stream can be expected to render the filters ineffective in a short period.
A release through an Interfacing System (NC) would not be filtered and per the above, a release through a filter is not indirect...... so it's direct?
Page 118, ------Second bullet - Containment isolation was not successful on a line that can allow a release of radioactive material to the environment. As used in this threshold, "direct" means that the line provides a pathway for the migration of radioactive materials from the RCS or containment atmosphere to a point in the plant where the material enters, or can become entrained in, a ventilation system flow path that ultimately exhausts to the environment. A line that is part of an intact closed liquid system is not a "direct" pathway.
The existence of an in-line filter does not make a release path indirect since the filter is not effective at removing fission product noble gases. Filters typically have an efficiency of 95-99% for removal of iodine. Given the magnitude of the core inventory of iodine, significant releases could still occur. In addition, since the fission product release would be driven by boiling in the reactor vessel, the high humidity in the release stream can be expected to render the filters ineffective in a short period.