Conflicting Waste Acceptance Criteria at the Interim Store

The drum must not enter the low-dose storage area on the strength of its original consignment record. The measured contact dose of 1.8 mSv/h exceeds the 0.5 mSv/h storage segregation threshold, so under the site WAC the package must be handled as intermediate-level for storage purposes and placed in a high-dose bay. This is a storage classification decision driven by the WAC, not a re-determination of the regulatory waste class; the two must be kept distinct in the record.

The original record cannot be relied on because it is contradicted by measurement and the supporting characterization report is missing. The regulator's requirement that discrepancies be resolved before movement means the drum should be held in a controlled quarantine position (or a high-dose bay if the quarantine area cannot meet the dose constraint) until the characterization is reconstructed. The 1.8 mSv/h reading is also close enough to the 2 mSv/h contact limit that a repeat measurement with a calibrated instrument, plus a check for surface contamination and package integrity, is warranted before any further movement. The 12 free high-dose bays are sufficient, so capacity is not a constraint on the conservative decision.

Reclassifying the waste outright is premature and would create a record that may not survive audit. The measured dose rate is a package-level property influenced by shielding, geometry, and sludge distribution; it does not by itself establish the radionuclide inventory or activity concentration that underpin the regulatory waste class. Without the characterization report, the generator cannot demonstrate the activity levels, the presence or absence of long-lived or alpha-emitting nuclides, or the chemical form of the sludge.

There are also operational consequences. Moving the drum to the intermediate route removes it from the low-level disposal campaign in 9 months and places it on a route with no scheduled campaign, which increases storage duration and the associated monitoring and inspection burden. A defensible path is to reconstruct the characterization from generator records, process knowledge, and confirmatory sampling or assay, then make the classification decision on that basis. If the reconstructed inventory supports low-level classification and the dose reading is explained by shielding or geometry, the drum can return to the low-level route. If not, reclassification is justified by evidence rather than by convenience. Either way, the discrepancy must be documented and closed before movement.

The record should contain the original consignment documentation, the audit finding, the measured dose rates and the instrument calibration certificates, the repeat measurement results, the reconstructed characterization with its basis (process knowledge, generator records, assay or sampling results), and a clear statement of the classification decision and its rationale. It should also record the storage location assigned, the WAC clause applied, and the disposition route chosen.

Quality assurance features include traceability of every measurement to a calibrated instrument and a named operator, independent review of the classification decision by someone not involved in the original consignment, and a documented reconciliation showing how the discrepancy between 0.3 mSv/h recorded and 1.8 mSv/h measured was explained or left unresolved. The record should be dated, version-controlled, and retained for the period required by the site's records schedule. If the discrepancy cannot be fully explained, that limitation should be stated explicitly rather than smoothed over, and the package should carry a flag in the inventory system so that the open item is visible to future handlers.