ML22144A294
| ML22144A294 | |
| Person / Time | |
|---|---|
| Issue date: | 06/01/2022 |
| From: | Leslie Fields Licensing Processes Branch |
| To: | |
| Fields L | |
| References | |
| Download: ML22144A294 (6) | |
Text
NRC PRESENTATION SLIDE FOR THE NEI 9901 PUBLIC MEETNG, JUNE 13, 2022 Changed EAL (R6) Description Change Category NEI/Industry Justification NRC/NEI Discussion Items AA1 EAL 1, Readings on ANY of the following Deleted EAL Radiation effluent threshold values based on Most of the non-dose assessment EALs identify dose assessment related EALs as a AS1 EAL 1, radiation monitors greater than the instrumentation setpoints alone require diverse EAL set to ensure timely and accurate EAL assessments. Please provide AG1, EAL 1, reading shown for 15 minutes or numerous assumptions that could result in appropriate guidance that would ensure site-specific EAL schemes would include Effluent monitoring based longer: (site-specific monitor list and inappropriate EAL classifications. Using an appropriate methods to perform timely and accurate EAL declarations if dose on instrument setpoints threshold values) on-shift dose assessor would provide more assessment capability was lost or impaired.
alone was deleted. accurate EAL classifications.
CG1 was deleted Loss of (reactor vessel/RCS [PWR] Deleted EAL Due to the inaccuracies associated with Because cold dose assessments may not be sufficiently accurate, an initiating or RPV [BWR]) inventory affecting directly, or indirectly, determining Reactor condition (EAL) to address the inability to maintain the core covered with the fuel clad integrity with containment vessel/RCS or RPV level, this EAL was containment challenged should be maintained. This EAL should be diverse to one challenged. deleted. Additionally, there is a longer based on dose assessment. The NRC staff expects this EAL to be based on site-available response time during shutdown specific plant conditions and further understands that an alternate EAL may be conditions. provided that has different conditions and/or timing than the current version of CG1.
FPB Table 9-F-2 BWR Site-specific indications that RCS Enhancement The 300 Ci/gm dose equivalent I-131 A threshold value based on reactor coolant sampling as part of the fission product Fuel Clad Barrier Loss 1.A activity is greater than 300 Ci/gm corresponds to an approximate range of 2% barrier matrix may not be timely and should not be included as an option as a fission was changed dose equivalent I-131 is being to 5% fuel clad damage is being replaced with product matrix threshold value. It may be appropriate to have a sampling threhold changed to site-specific indications approximately 2% to promote greater value as a system malfunction. If sampling were included as an ALERT under system that RCS activity is greater than consistency. malfunctions, then any issues associated with accurate sampling would have less
~2% fuel clad failure. potential to impact a site area emergency or general emergency as part of the significance determination process.
FPB Table 9-F-2 BWR A. Dose assessment using actual New EAL These thresholds are a replacement for the What about a field survey that is 8 miles away? At what level of radiation outside of CNMT Barrier Potential meteorology indicates doses greater existing radiation monitor reading threshold in the containment do we say that the containment barrier is lost? The primary concern Loss 3.A and 3.B was than 750 mrem TEDE at or beyond Containment Barrier Potential Loss 4.A. is that a dose rate of 750 mrem several miles from the plant could reasonably added (site-specific dose receptor point). Releases of this magnitude are greater than correspond to higher dose rates closer to the plant. Identification of the Site-Specifc OR normal and, when combined with the loss of Dose Receptor point,could address this concern.
B. Field survey results indicate the fuel clad and RCS barriers, warrant the closed window dose rates greater declaration of a General Emergency.
than 750 mR/hr at or beyond (site-specific dose receptor point) that are expected to continue for 60 minutes or longer.
SLIDE 1 of 6
NRC PRESENTATION SLIDE FOR THE NEI 9901 PUBLIC MEETNG, JUNE 13, 2022 Changed EAL (R6) Description Change Category NEI/Industry Justification NRC/NEI Discussion Items FPB Table 9-F-2 BWR Primary containment radiation Deleted EAL This threshold is unnecessary as plants have The NEI justification includes a reference to site-specific post-accident samling system Fuel Clad Barrier Loss 4.A monitor reading greater than (site- other, more reliable means for determining capabilities. Do licensees typically use site-specific post-accident sampling systems?
was deleted specific value). the status of the Fuel Clad Barrier. Would these samples be timely? Please ensure that guidance would ensure that EAL Specifically, sites have a variety of safety- threshold values are based on indications that would reasonably be considered as related indications (e.g., RPV level, primary timely.
containment hydrogen concentration, etc.)
that serve this purpose.
FPB Table 9-F-2 BWR Primary containment radiation Deleted EAL This threshold is unnecessary as plants have If, as stated by the NEI, that licensees have a 'variety of safety-related indications' RCS Barrier Loss 4.A was monitor reading greater than (site- other, more reliable means for determining then threshold values should be based on those indications instead of containment deleted specific value). the status of the RCS Barrier. Specifically, radiation monitor readings.
sites have a variety of safety-related indications to identify RCS leakage (e.g., RPV level, primary containment pressure, primary containment temperature, etc.).
FPB Table 9-F-3 PWR Containment radiation monitor Deleted EAL This threshold is unnecessary as plants have The NEI justification includes a reference to site-specific post-accident samling system Fuel Clad Barrier Loss 3.A reading greater than (site-specific other, more reliable means for determining capabilities. Do licensees typically use site-specific post-accident sampling systems?
was deleted value). the status of the Fuel Clad Barrier. Would these samples be timely? Please ensure that guidance would ensure that EAL Specifically, sites have a variety of safety- threshold values are based on indications that would reasonably be considered as related indications (e.g., core exit timely.
thermocouples, reactor vessel level, containment hydrogen concentration, etc.)
that serve this purpose.
FPB Table 9-F-3 PWR Site-specific indications that RCS Enhancement The 300 Ci/gm dose equivalent I-131 A threshold value based on reactor coolant sampling as part of the fission product Fuel Clad Barrier Loss 3.B activity is greater than 300 Ci/gm corresponds to an approximate range of 2% barrier matrix may not be timely and should not be included as an option as a fission was changed dose equivalent I-131 is being to 5% fuel clad damage is being replaced with product matrix threshold value. It may be appropriate to have a sampling threhold changed to site-specific indications approximately 2% to promote greater value as a system malfunction. If sampling were included as an ALERT under system that RCS activity is greater than consistency. malfunctions, then any issues associated with accurate sampling would have less
~2% fuel clad failure. potential to impact a site area emergency or general emergency as part of the significance determination process.
SLIDE 2 of 6
NRC PRESENTATION SLIDE FOR THE NEI 9901 PUBLIC MEETNG, JUNE 13, 2022 Changed EAL (R6) Description Change Category NEI/Industry Justification NRC/NEI Discussion Items FPB Table 9-F-3 PWR Containment radiation monitor Deleted EAL This threshold is unnecessary as plants have If, as stated by the NEI, that licensees have a 'variety of safety-related indications' RCS Barrier Loss 3.A was reading greater than (site-specific other, more reliable means for determining then threshold values should be based on those indications instead of containment deleted value). the status of the RCS Barrier. Specifically, radiation monitor readings.
sites have a variety of safety-related indications to identify RCS leakage (e.g., PZR level, RCS pressure, containment pressure, containment temperature, etc.).
FPB Table 9-F-3 PWR A. Dose assessment using actual New EAL These thresholds are a replacement for the What about a field survey that is 8 miles away? At what level of radiation outside of CNMT Barrier Potential meteorology indicates doses greater existing radiation monitor reading threshold in the containment do we say that the containment barrier is lost? The primary concern Loss 4.C and 4.D was than 750 mrem TEDE at or beyond Containment Barrier Potential Loss 4.C. is that a dose rate of 750 mrem several miles from the plant could reasonably added (site-specific dose receptor point). Releases of this magnitude are greater than correspond to higher dose rates closer to the plant. Identification of the Site-Specifc OR normal and, when combined with the loss of Dose Receptor point,could address this concern.
B. Field survey results indicate the fuel clad and RCS barriers, warrant the closed window dose rates greater declaration of a General Emergency.
than 750 mR/hr at or beyond (site-specific dose receptor point) that are expected to continue for 60 minutes or longer.
SLIDE 3 of 6
NRC PRESENTATION SLIDE FOR THE NEI 9901 PUBLIC MEETNG, JUNE 13, 2022 Changed EAL (R6) Description Change Category NEI/Industry Justification NRC/NEI Discussion Items HU3, EALs 1, 3, 4, and 5 Hazardous Event New EAL Deleted IC - EALs #1, #3, #4, and #5 are This was an emerging discussion/issue during earlier EAL scheme development were deleted. EAL 2 was (1) A tornado strike within the unnecessary as the covered events present a public meetings. Based on recent NRC staff discussions, a new EAL is not needed to relocated. EAL HU3 was PROTECTED AREA. (2) Internal very low safety risk to the public. Sites have support a change to 10 CFR 50.72.
replaced with a loss of room or area flooding of a sufficient procedures and capabilities to TSC or EOF EAL, which magnitude sufficient to require respond to these events without the need to is a new EAL. manual or automatic electrical activate an emergency plan (e.g., use of isolation of a SAFETY SYSTEM protocols and resources for responding to component needed for the current severe weather or industrial accidents). EAL operating mode. (3) Movement of #2 was retained but relocated to Recognition personnel within the PROTECTED Categories C and S as IC CU6 and IC SU7, AREA is impeded due to an offsite respectively. New IC - The EAL for the new event involving hazardous materials IC HU3 addresses a condition that would (e.g., an offsite chemical spill or present a challenge to the effective toxic gas release). (4) A hazardous implementation of the emergency plan. Note:
event that results in on-site The addition of the new IC HU3 is contingent conditions sufficient to prohibit the on the outcome of future NRC interactions plant staff from accessing the site concerning rulemakings related to 10 CFR via personal vehicles. 50.72 and 10 CFR 50.54(t).
(5) (Site-specific list of natural or technological hazard events)
HU4 was deleted FIRE potentially degrading the level Deleted EAL This IC and the associated EALs are EALs HU4.3 and HU4.4 should be retained as fires of this magnitude can impact plant of safety of the plant. unnecessary as the covered events present a safety and emergency plan implementation.
very low safety risk to the public. Sites have sufficient procedures and capabilities to respond to these events without the need to activate an emergency plan (e.g., use of protocols and equipment described in the site Fire Protection Program). In particular, a site would be able to perform firefighting and a post-event damage assessment, and identify and implement the necessary corrective/compensatory measures without mobilizing the ERO.
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NRC PRESENTATION SLIDE FOR THE NEI 9901 PUBLIC MEETNG, JUNE 13, 2022 Changed EAL (R6) Description Change Category NEI/Industry Justification NRC/NEI Discussion Items SU5 was deleted Automatic or manual (trip [PWR] / Deleted EAL This IC and the associated EALs are If NEI/Industry would propose an ATWS EAL set, consider having wording such as scram [BWR]) fails to shutdown the unnecessary as the covered condition "the reactor is shutdown as determined by the CRS/SRO." By providing guidance that reactor. presents a very low safety risk to the public. this determination should be based on site-specific procedures, this wording would be Sites have sufficient procedures and ensure that emergency operating procedures and emergency response procedures capabilities to respond to an unsuccessful are aligned and are based on the reactor actually being shutdown. If NEI/Industry reactor trip/scram without the need to activate would propose to remove the ATWS EAL set, then sufficient objective evidence an emergency plan. For this IC, although should be provided that provides the NRC staff with a basis for a risk informed there was an issue with the RPS, the plant determination.
was promptly shutdown following the initial trip/scram failure and no fission product barrier was challenged.
SA5 was deleted Automatic or manual (trip [PWR] / Deleted EAL This IC and the associated EALs are SU5 comments apply to the ATWS set.
scram [BWR]) fails to shutdown the unnecessary as the covered event does not reactor, and subsequent manual present a level of risk to the public actions taken at the reactor control commensurate with an Alert declaration. Sites consoles are not successful in have procedures and capabilities to respond shutting down the reactor. to an unsuccessful reactor trip/scram without the need to activate an emergency plan. This includes the use of alternative measures to shut down the plant before a fission product barrier is challenged (e.g., local opening of reactor trip breakers). Should the event lead to a challenge of either the Fuel Clad Barrier or RCS Barrier, then an Alert classification would be made in accordance with the thresholds in the Fission Product Barrier Tables. Absent such a challenge, an Alert declaration is not appropriate.
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NRC PRESENTATION SLIDE FOR THE NEI 9901 PUBLIC MEETNG, JUNE 13, 2022 Changed EAL (R6) Description Change Category NEI/Industry Justification NRC/NEI Discussion Items SS5 was deleted Inability to shutdown the reactor Deleted EAL This IC and the associated EALs are SU5 comments apply to the ATWS set.
causing a challenge to (core cooling unnecessary as the classification of this
[PWR] / RPV water level [BWR]) or condition is adequately addressed by the RCS heat removal. thresholds in the Fission Product Barrier (FPB) Tables. The two bulleted 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 Site Area Emergency declaration under a FPB Table, regardless of the ATWS.
Removing IC SS5 simplifies the emergency classification process.
SG1 was deleted Prolonged loss of all offsite and all Deleted EAL This EAL is unnecessary because Need to develop a version of SG1 that addresses the increased risk presented by an onsite AC power to emergency classification of this condition is adequately extended loss of AC power and provide appropriate guidance to support timely and buses. addressed by the Fission Product Barrier accurate EAL classifications. This EAL should address conditions where the loss of (FPB) Tables. In the case where a AC power strategies required by 10 CFR 50.155 are not effective.
declaration is based on the inability to adequately remove heat from the core, there would have to be a Potential Loss or Loss of both the Fuel Clad Barrier and the RCS Barrier. This means that the loss of all offsite and all onsite AC power is a proxy for a Potential Loss of the Containment Barrier. As such, the declaration of the General Emergency would lead to a premature evacuation even though containment failure is not imminent. The thresholds in the FPB Tables address challenges to containment integrity and would result in the timely declaration of a General Emergency.
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