GB15146.8-2008
Nuclear criticality safety for fissile materials outside reactors - Part 8: Criticality safety criteria for the handling , storage, and transportation of LWR fuel outside reactors
反应堆外易裂变材料的核临界安全 第8部分：堆外操作、贮存、运输轻水堆燃料的核临界安全准则
GB 15146.8-2008 is a current mandatory Chinese national standard for Nuclear criticality safety for fissile materials outside reactors - Part 8: Criticality safety criteria for the handling , storage, and transportation of LWR fuel outside reactors. It appears in the Construction compliance cluster with a product safety focus and has an implementation date of Aug 1, 2009.
Applicability depends on product scope, certification route, competent authority notices and transition rules. Requst for the translation or verify source before using this record in a compliance decision.
Compliance overview
Scope and applicability
This standard specifies the nuclear criticality safety criteria for the out-of-reactor handling, storage, and transportation of light water reactor (LWR) fuel rods and fuel units. It is mandatory for all facilities and operations involving these specific nuclear materials outside the reactor core. The standard does not cover administrative measures directly, which are referenced in GB 15146.1.
Technical requirements
GB 15146.8-2008 mandates that a comprehensive nuclear criticality safety evaluation must be conducted before the initial operation or any modification to systems handling LWR fuel. This evaluation must identify and explicitly state the controlled parameters and their design/operational limits to ensure the system remains subcritical under all normal and credible abnormal conditions. The standard introduces a statistically based subcriticality criterion. It requires that the calculated neutron multiplication factor ($k_p$) must be less than or equal to a permitted value, accounting for various uncertainties and margins. Engineers must calculate and validate these margins to guarantee a sufficient safety coefficient, ensuring that at least two independent and unlikely changes must occur simultaneously to trigger a criticality accident. When relying on neutron absorbers (such as gadolinium or boron) in fuel, structures, or solutions, the standard mandates strict control measures to maintain their predetermined distribution and concentration. Furthermore, when evaluating fuel reactivity, parameters must be selected to yield the maximum neutron multiplication factor, carefully considering the effects of burnup and axial distribution.
Testing methods
The standard outlines evaluation and verification methods rather than physical material testing. Key methods include calculating the effective multiplication factor ($k_{eff}$) using validated computational methods, comparing against benchmark critical experiments, and performing in-situ subcritical neutron multiplication measurements as specified in GB 15146.7. An independent assessment by qualified personnel is required to verify the correctness of the safety evaluation.
FAQs
What products and operations are regulated under GB 15146.8-2008?
This standard applies to the out-of-reactor handling, storage, and transportation of light water reactor (LWR) fuel rods and fuel units. It is mandatory for all operations involving these specific nuclear materials outside the reactor core.
Are there any significant updates from the previous version, GB 15146.8-1994?
The 2008 version expanded the scope to include LWR fuel rods. It also introduced a method for establishing subcriticality criteria based on statistical concepts, and removed previous administrative measures, replacing the auxiliary verb "must" with "should" (shall) for mandatory requirements and "should" (should) for recommendations.
How does GB 15146.8-2008 relate to international standards?
GB 15146.8-2008 establishes domestic criteria for LWR fuel operations and references several other parts of the GB 15146 series, such as GB 15146.2 for basic technical rules. Engineers should compare its subcriticality calculation methods with IAEA safety standards to ensure full international compliance.
The summary above provides a high-level overview of GB 15146.8-2008. To ensure complete compliance for your products entering the Chinese market, a precise and professional translation of the full technical specifications is essential. Purchase our high-quality English translation of GB 15146.8-2008 today to access all detailed parameters, tables, and testing procedures.
Applicability hints
- Type
- Safety
- CCS
- F09
- ICS
- 27.120
- Competent department
- State Administration of Science, Technology and Industry for National Defense
- Technical committee
- State Administration of Science, Technology and Industry for National Defense
Relationships
Replaces:GB 15146.8-1994