ML22277A444

10/05 NRC Staff Public Meeting Comments on NEI 99-01, Revision 7, Draft G

ML22277A444
Person / Time
Issue date:	10/05/2022
From:	Leslie Fields Licensing Processes Branch
To:
Fields L, NRR/DORL/LLPB
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Download: ML22277A444 (1)

Text

NRC Staff Public Meeting Comments on NEI 99-01, Revision 7, Draft G

1. Because 10 CFR 50.72, Immediate notification requirements for operating nuclear power reactors, may be changed or eliminated and does not support EAL scheme development, the NRC staff recommends eliminating Section 1.2, Immediate Notification Requirements Per 10 CFR 50.72.

2. Because of frequent confusion over the use of the term Emergency Action Level (EAL),

the NRC staff recommends including the last sentence in Section 3.4, Organization and Presentation of Generic Information, in Section 2.3, Emergency Action Level (EAL).

3. Because of the importance of dose assessment, the NRC staff recommends including a discussion on the importance of properly maintained and calibrated instrumentation to ensure timely and accurate dose assessments.

4. Developer Note 2 for the fission product barrier matrix includes an example where the fission product barrier matrix may indicate that a site area emergency declaration is appropriate while dose assessment may indicate that a general emergency declaration is appropriate. Because it is reasonable that there may be conditions where dose assessment may indicate that a site area emergency declaration is appropriate while the fission product barrier matrix may indicate that a general emergency declaration is appropriate, the NRC staff requests NEI to consider adding or vice versa to the end of Developer Note 2 for the fission product barrier matrix.

5. The PWR fuel clad barrier loss is based only on core exit thermocouple temperatures (CETs). This would cause a PWR fission product barrier general emergency declaration to rely on a single system. Although it appears that the BWR fission product barrier is also limited by a single condition, severe accident guide (SAG) entry required, SAG entry is based on an assessment of redundant and diverse indications. Because of the importance of the fission product barrier matrix, please provide a method to assess a loss of fuel clad barrier that is based on diverse and redundant reactor coolant system instrumentation.

6. The fission product barrier matrix in Draft G of NEI 99-01, Revision 7, currently provides a radiation-based criterion for a potential loss of the containment barrier. Because this threshold is 75% of the threshold value for radiological effluents, both the RCS and fuel clad barriers would reasonably be lost. However, there are no radiation-based threshold values for a loss of the RCS barrier or a loss of the fuel clad barrier. Because there are no radiation-based threshold values for a loss of the RCS and fuel clad barriers, the fission product barrier matrix is dependent on RCS instrumentation for declarations of either a site area emergency or general emergency. To provide EAL scheme diversity, please provide radiation-based thresholds for the RCS and fuel clad barriers. Note: a consistent logic could be used like that of the potential loss of a containment barrier.