临界限值 meaning in Chinese

threshold limiting
tlv

Nuclear criticality safety for fissile materials outside reactors - nuclear criticality control criteria and subcritical limits for plutonium - natural uranium mixtures
反应堆外易裂变材料的核临界安全钚-天然铀混合物的核临界控制准则和次临界限值
Nuclear criticality safety for fissile materials outside reactor - basic technical criteria and subcritical limits for handling , processing and operations of fissile materials
反应堆外易裂变材料的核临界安全易裂变材料操作加工处理的基本技术准则与次临界限值