ML24072A351
| ML24072A351 | |
| Person / Time | |
|---|---|
| Issue date: | 03/15/2024 |
| From: | Leslie Fields Licensing Processes Branch |
| To: | Gerond George Licensing Processes Branch |
| References | |
| Download: ML24072A351 (1) | |
Text
Summary of IC and EAL Change Comments and Questions in NEI 99-01 Revision 7 Page 1 of 6 The table below summarizes the changes made to the Initiating Conditions and Emergency Action Levels found to be unacceptable or have editorial corrections needed.
Rev. 6 IC and EAL#
Rev. 6 Wording Rev. 7 IC and EAL#
Rev. 7 Wording Change Summary/Basis IC AU1 EAL #1 EAL #2 EAL #3 Release of gaseous or liquid radioactivity greater than 2 times the (site-specific effluent release controlling document) limits for 60 minutes or longer.
N/A None - deleted.
Unnecessary as the covered events very low risk to public.
Activation of the site emergency plan (E-plan) and ERO are not necessary.
Sites have procedures and capabilities to respond.
IC AA1 appropriately bounds releases.
- 1 (1) Reading on ANY of the following radiation monitors greater than the reading shown for 15 minutes or longer:
(site-specific monitor list and threshold values)
N/A None - deleted.
Deleted, may lead to inappropriate declaration.
EAL thresholds use assumed source terms and met data likely different from actual event.
Dose assessment using actual effluent monitor readings and met data would yield a declaration more reflective of the actual plant conditions.
Developer note added stating ERFs responsible for dose projections have reliable dose assessment capability (i.e., primary and backup).
Plant indications are available to support timely and accurate classifications for releases > the EPA PAGs should dose assessment capability be lost.
Survey data from onsite and/or offsite monitoring teams would be available to support emergency classification decision-making.
With respect to the use of averaged meteorological data from a plant computer, the differences between any two consecutive data sets (e.g., 15-minute averages delivered on the quarter hour) would not be significant Note NUREG-1935 the SOARCA Report states no sequences resulted in a large early release, even considering external events and unsuccessful mitigation
Summary of IC and EAL Change Comments and Questions in NEI 99-01 Revision 7 Page 2 of 6 Rev. 6 IC and EAL#
Rev. 6 Wording Rev. 7 IC and EAL#
Rev. 7 Wording Change Summary/Basis IC AA1 EAL #3 (3) Analysis of a liquid effluent sample indicates a concentration or release rate that would result in doses greater than 10 mrem TEDE or 50 mrem thyroid CDE at or beyond (site-specific dose receptor point) for one hour of exposure.
N/A None - deleted.
unnecessary as it is bounded by other EALs.
dilution and dispersion between liquid source and site boundary - unlikely threshold could be reached.
Required source term greater than typically available during normal operations (e.g., fuel defect or cladding failure).
higher source term would be met by another EAL.
Report to NRC required by 10 CFR 50.72(b)(2)(xi).
No effect on E-plan or Security Plan activation, or No ERO mobilization or offsite support required.
ORO safety and environmental officials would take actions to minimize the risk to the public.
FPB Tables 9-F-2 & 3 RCS Barrier Loss FPB Tables 9-F-2 & 3 CNMT Barrier Potential Loss Primary containment radiation monitor reading greater than (site-specific value).
N/A None - deleted.
Primary containment radiation monitor threshold uses assumed source term and instantaneous dispersal of RCS inventory. Assumptions may not align with actual event affecting threshold accuracy.
Containment monitors may see radioactive shine from piping, which also affects accuracy.
identification significant challenge RCS barrier will be made using safety-related indications for primary containment pressure, RPV water level, and detection of high energy line breaks. These indications are highly reliable (e.g., subject to the requirements in 10 CFR 50.65).
This approach will result in more timely and accurate assessments of the RCS Barrier status than from a primary containment rad monitor.
Summary of IC and EAL Change Comments and Questions in NEI 99-01 Revision 7 Page 3 of 6 Rev. 6 IC and EAL#
Rev. 6 Wording Rev. 7 IC and EAL#
Rev. 7 Wording Change Summary/Basis FPB Table 9-F-2 Fuel Clad Barrier Loss 4.A FPB Table 9-F-3 Fuel Clad Barrier Loss 3.A Primary containment radiation monitor reading greater than (site-specific value).
FPB Table 9-F-2 Fuel Clad Barrier Loss 3.A FPB Table 9-F-3 Fuel Clad Barrier Loss 1.C
- Alternative threshold to the one above **
Primary containment radiation monitor reading greater than (site-specific value).
- Alternative threshold for Fuel Clad Barrier Loss threshold 1.C **
Containment radiation monitor reading greater than (site-specific value).
Containment radiation monitor reading is calculated using an assumed source term and instantaneous dispersal of RCS inventory into containment.
These assumptions may not align with actual event, affecting the threshold accuracy.
containment monitors could see radioactive shine from piping sources or influenced by sprays, natural deposition/plateout, atmospheric leakage, natural and forced convection, filters, and suppression pools, also affect assessment accuracy.
primary containment radiation monitor reading, while retained, was reassigned as an alternative threshold (A core damage assessment indicates FUEL CLAD DAMAGE threshold).
identification of significant fuel clad barrier challenge typically made using safety-related indications for RPV water level.
indicators are subject to 10 CFR 50.65 and support EOP diagnostic and mitigation actions.
N/A N/A FPB Table 9-F-2 CNMT Barrier Potential Loss 3.A and 3.B A. Dose assessment using actual meteorology indicates doses greater than 750 mrem TEDE at or beyond (site-specific dose receptor point).
OR B. Field survey results indicate closed window dose rates greater than 750 mR/hr at or beyond (site-specific dose receptor point) that are expected to continue for 60 minutes or longer.
Set to 75% of the lower limit of the EPA PAG for sheltering-in-place or evacuation of the public.
Releases of this magnitude are far greater than normal containment leakage and, when combined with the loss of the fuel clad and RCS barriers, warrant the declaration of a General Emergency (GE).
Resulting PARs, which may include an evacuation, will be more appropriate given that a significant release is in progress (i.e., one that is well in excess of what would be expected from normal containment leakage).
Summary of IC and EAL Change Comments and Questions in NEI 99-01 Revision 7 Page 4 of 6 Rev. 6 IC and EAL#
Rev. 6 Wording Rev. 7 IC and EAL#
Rev. 7 Wording Change Summary/Basis FPB Table 9-F-3 Fuel Clad Barrier Potential Loss 2.B B. Inadequate RCS heat removal capability via steam generators as indicated by (site-specific indications).
N/A None - deleted.
Threshold deleted because the condition does not present an immediate threat to Fuel Clad Barrier.
During this condition, operators (following EOPs) will initiate a feed and bleed cooldown of the RCS.
Absent additional failure this cooldown method is sufficient to prevent challenge of Fuel Clad Barrier.
If an additional failure occurred that lead to an actual Fuel Clad Barrier challenge, other Potential Loss or Loss threshold would be met ensuring appropriate escalation.
FPB Table 9-F-3 CNMT Barrier Potential Loss 4.C C. 1. Containment pressure greater than (site-specific pressure setpoint)
AND
- 2. Less than one full train of (site-specific system or equipment) is operating per design for 15 minutes or longer.
FPB Table 9-F-3 CNMT Barrier Potential Loss 4.C This should be 3.C C. Dose assessment using actual meteorology indicates doses greater than 750 mrem TEDE at or beyond (site-specific dose receptor point).
Threshold deleted because it may lead to a GE declaration and PARs for conditions where no (or a minimal) release in progress and no immediate challenge to containment integrity.
Atmospheric pressure-related challenges to containment integrity are best bounded by Containment Barrier Potential Loss threshold 43.A, Containment pressure greater than (site-specific value), where the value is the containment design pressure.
threshold replaces existing radiation monitor Containment Barrier Potential Loss 3.A threshold.
It is set to 75% of the lower limit of the EPA PAG for sheltering-in-place or evacuation of the public.
Releases of this magnitude exceed normal containment leakage and combined with a loss of fuel clad and RCS barriers, warrant an GE declaration.
PARs, which may include an evacuation, will be more appropriate given that a significant release is in progress (i.e., one that is well in excess expected from normal containment leakage).
Summary of IC and EAL Change Comments and Questions in NEI 99-01 Revision 7 Page 5 of 6 Rev. 6 IC and EAL#
Rev. 6 Wording Rev. 7 IC and EAL#
Rev. 7 Wording Change Summary/Basis IC CS1 EAL #1 (1) a. CONTAINMENT CLOSURE not established.
AND
- b. (Reactor vessel/RCS[PWR] or RPV[BWR]) level less than (site-specific level).
IC CS1 EAL #1 (1) a. CONTAINMENT CLOSURE not established.
AND
- b. (RHR flow is lost and not restored within 30 minutes [PWR] or RPV level less than (site-specific level) [BWR]).
EAL 1.b, replace reactor vessel/RCS level criterion with a loss of RHR flow for 30 minutes.
change focuses on loss of RHR flow, which is what the prior wording on reactor vessel/RCS level was concerned with (i.e., replaced the cause [low level leading to RHR suction loss] with the effect [lost RHR flow]).
This change address EAL range limitation issues experienced by some sites available instruments.
IC SU2 EAL #1 UNPLANNED loss of Control Room indications for 15 minutes or longer.
N/A None - deleted.
This IC and EAL is unnecessary as the condition presents a very low safety risk to the public.
Sites have procedures and capabilities to respond to this condition without activating the E-plan.
A site can assess equipment failure(s) and identify and implement necessary corrective/compensatory measures without mobilizing the ERO.
Some plant response actions may also be required by Technical Specifications.
This condition would lead to a 10 CFR 50.72 report to the NRC and, depending on concurrent events or resulting impacts, may necessitate an emergency declaration under another IC.
Should this condition occur in conjunction with a reactor trip or ECCS (SI) actuation, then an Alert would be declared in accordance with IC SA2.
Summary of IC and EAL Change Comments and Questions in NEI 99-01 Revision 7 Page 6 of 6 Rev. 6 IC and EAL#
Rev. 6 Wording Rev. 7 IC and EAL#
Rev. 7 Wording Change Summary/Basis IC HU3 EAL #1 EAL #3 EAL #4 EAL #5 Hazardous Event (1) A tornado strike within the PROTECTED AREA.
(3) Movement of personnel within the PROTECTED AREA is impeded due to an offsite event involving hazardous materials (e.g.,
an offsite chemical spill or toxic gas release).
(4) A hazardous event that results in on-site conditions sufficient to prohibit the plant staff from accessing the site via personal vehicles.
N/A None - deleted.
Deleted IC - EALs #1, #3, #4, and #5 are unnecessary, events are very low risk to the public.
Sites have procedures and capabilities to respond to these events without the need to activate an emergency plan (e.g., use of protocols and resources for responding to severe weather or industrial accidents).
Sites can perform post-event damage assessments, identify and implement necessary corrective/
compensatory measures without the ERO.
Depending on the event, plant response actions may be required by Technical Specifications.
If an event has more than minor impact, it would result in a 10 CFR 50.72 NRC report or an emergency declaration under another IC.
EAL #2 was relocated to Recognition Categories C and S as IC CU6 and IC SU7, respectively.
IC SS5 Inability to shutdown the reactor causing a challenge to (core cooling [PWR] /
RPV water level [BWR]) or RCS heat removal.
N/A None - deleted.
IC and EALs are unnecessary - classification of this condition is addressed by the Fission Product Barrier (FPB) table thresholds.
The two conditions in EAL statement (1).c entail a Potential Loss or Loss of both the Fuel Clad Barrier and the RCS Barrier; this condition would lead to a FPB Table Site Area Emergency declaration, regardless of ATWS.
Removing IC SS5 simplifies the emergency classification process.