The team identified a
Severity Level IV violation of
10 CFR 50.59 requirements for failing to evaluate a modification to spent fuel storage in the spent fuel pools. The team reviewed CRDR 2524176, regarding the lack of a criticality analysis to support the use of rod capture tubes, which hold individual harvested fuel pins, in the spent fuel rack. The team reviewed the licensee's process of storing individual fuel pins, removed from a parent fuel assembly, and placed in rod capture tubes to be located in guide tubes of another host assembly. This resulted in a component that had nuclear fuel pins, of varying enrichment and depletion, stored as a regular fuel assembly in the spent fuel pools. The team noted that Section 9.1 of the
UFSAR specifically described the storage of spent fuel in regions based upon fuel assembly initial enrichment, actual burnup, and actual decay time. The
UFSAR does not describe the storage of individual pins in these regions. The licensee previously interpreted this as meaning the
UFSAR did not prohibit such storage, and would not require consideration of enrichment, burnup, and decay of individual pins. The licensee failed to provide an evaluation of a change to the facility as described in the
UFSAR, under
10 CFR 50.59 requirements. The licensee subsequently performed an evaluation of the criticality under station procedure
72DP-9NF01, "Control of
SNM Transfer and Inventory," which was found acceptable
The issue was determined to be more than minor, through
Inspection Manual Chapter 0612, Appendix B, in that it affected the
barrier integrity cornerstone attribute of human performance, and could have represented a more significant issue if left uncorrected. In accordance with the
NRC Enforcement Manual, violations of
10 CFR 50.59 are not processed through the
significance determination process. Therefore, this issue was considered applicable to traditional enforcement. Although the
significance determination process is not designed to assess significance of violations that potentially impact or impede the regulatory process, the result of a
10 CFR 50.59 violation can be assessed significance through the
significance determination process. The team leader and the Region IV senior reactor analyst discussed the significance of this finding. An
SDP Phase 1 screening was performed and the finding was determined to have very low safety significance because there was no actual loss of the
barrier integrity function. The licensee entered this issue into its corrective action program as CRDR 2711241.
