ML22167A192
| ML22167A192 | |
| Person / Time | |
|---|---|
| Site: | Hermes |
| Issue date: | 06/16/2022 |
| From: | Kairos Power |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML22167A190 | List: |
| References | |
| KP-NRC-2206-007 | |
| Download: ML22167A192 (4) | |
Text
KP-NRC-2206-007 Enclosure 1 Changes to Hermes PSAR Chapter 14 (Non-Proprietary)
Preliminary Safety Analysis Report Technical Specifications Table 14.1-1: Proposed Variables and Conditions for Technical Specifications Section Section Name LCO or Condition Basis 2.0 Safety Limits (SL) and Limiting Safety System Settings (LSSS)
Safety Limits are those limits on process variables that are necessary to reasonably protect the integrity of certain physical barriers that are credited to preclude a potential uncontrolled release of radioactivity.
Limiting Safety System Settings are settings for automatic protective devices related to those variables having significant safety functions. These settings ensure that automatic protective action will correct the abnormal situation before a Safety Limit is exceeded.
This Table consists of examples of the proposed subjects of Safety Limits, and Limiting Safety System Settings and LCOs. These examples are provided below.
2.1 SL The core exit reactor coolantfuel The maximum core exit temperatures and the core reactor coolantfuel power shall not exceed an upper temperatures and core bound operating range under power operating range Safety any operating conditions. Limit are is established to ensure fuel integrity based on temperatures assumed in the safety analysis.
2.1 SL The reactor vessel surface The maximum reactor vessel temperatures shall not exceed an surface temperature Safety upper bound temperature under Limit is the maximum any condition of operation. temperature that can be permitted with confidence that vessel integrity will be maintained.
2.2 LSSS The core exit reactor coolant Limiting the maximum core temperature(s) shall not exceed exit coolant temperature will an upper bound temperature ensure that the Safety Limits under any condition of are not exceeded and that operation. the reactor will trip prior to reaching a Safety Limit.
2.2 LSSS The coolant level shall not fall Limiting the coolant low level below a lower bound limit under will ensure that adequate any condition of operation. core cooling is available so that the Safety Limits are not exceeded.
Kairos Power Hermes Reactor 14-3 Revision 0
Preliminary Safety Analysis Report Technical Specifications Section Section Name LCO or Condition Basis 2.2 LSSS The rate of flux trip function shall Limiting the rate of not exceed an upper bound limit power/flux increase will as specified in the safety analysis. ensure that the reactor will trip prior to challenging the integrity of fuel (or a limitation set in fuel performance methodology).
2.2 LSSS The high-power flux trip function Limiting the upper bound shall not exceed an upper bound limit will ensure that the limit as specified in the safety reactor will trip prior to analysis. challenging a safety limit assumed in the safety analysis.
3.0 Limiting Conditions for Operation (LCOs)
LCOs are derived from the safety analysis and are implemented administratively or by control and monitoring systems to ensure safe operation of the facility.
The LCOs are the lowest functional capability or performance level required for safe operation of the facility.
The proposed subjects of LCOs are provided below.
3.1 Reactor Core Pebble wear is within acceptable The objective is to ensure Parameters limits to support pebble that pebble wear is reinsertion. controlled within limits assumed by or associated with safety analyses, to prevent reinsertion if wear exceeds those limits.
Reactor power shall not exceed The objective is to limit the the licensed reactor power level. maximum operating power to ensure that the safety limits will not be exceeded.
3.2 Reactor Control and Reactivity coefficients are within The objective is to infer or Safety Systems limits over the allowable range of calculate reactivity operation. coefficients during normal plant operation to limit the severity of a reactivity transient.
Kairos Power Hermes Reactor 14-4 Revision 0
Preliminary Safety Analysis Report Technical Specifications Section Section Name LCO or Condition Basis 3.3 Coolant Systems The radionuclide inventory of the The objective is to limit key reactor coolant in steady state radionuclide inventories in (e.g., from transmutation of the reactor coolant during actinides) is maintained within steady state to ensure that an upper bound limit. any postulated event does not exceed limits.
Primary heat transport system The objective is to limit the pressure and flow rate are quantity and pressure of maintained within an upper spilled Flibe to ensure a bound limit. postulated event does not exceed limits.
Inlet Inert gas system pressure is The objective is to limit the maintained within an upper quantity and pressure of bound limit. spilled Flibe or cover gas to ensure a postulated event does not exceed limits.
Argon purity in the cover gas is The objective is to limit maintained within an upper radionuclides in the Flibe bound limit. below solubility limits where solute-solute interactions can be neglected.
The quantity of materials at risk The objective is to limit the in the gas space of the primary quantity of materials at risk heat transport system and the in the cover gas to ensure a primary heat rejection system is postulated event does not maintained within an upper exceed limits.
bound limit.
3.4 Engineered Safety Decay heat removal system The objective is to specify the Features operability requirement to have an operable decay heat removal system to ensure that the safety limits will not be exceeded.
Reactor vessel integrity The objective is to specify a design operating temperature limit to ensure the safety limit is not exceeded for postulated events.
Kairos Power Hermes Reactor 14-5 Revision 0