10 CFR 50.59 Safety Evaluations for Changes to Radioactive Waste Treatment Systems

HPPOS-086 PDR-9111210238

See IE Circular No. 80-18 entitled as above and dated August 22, 1980. For changes in a facility radioactive waste system as described in the SAR, a safety evaluation is required per 10 CFR 50.59. It also provides detailed guidance on application of 10 CFR 50.59 to radwaste systems.

Recent inspections at operating power reactors have revealed numerous instances in which licensees have failed to perform adequate safety evaluations to support changes made to the design and/or operation of facility radioactive waste treatment systems. These safety evaluations are required by 10 CFR 50.59 whenever changes are made in the facility as described in the Safety Analysis Report (SAR).

The inadequacies of the evaluations have caused radiological safety hazards to occur unidentified and therefore to remain unevaluated and uncorrected. In two particular cases, the inadequately evaluated system changes resulted in system failures that caused an uncontrolled release of radioactivity to the environment. In each of these situations, a proper 10 CFR 50.59 safety evaluation would have identified and corrected deficiencies in the system modification and/or operation and would have prevented the inadvertent release of radioactivity.

NRC follow-up examination of the situation indicates that the inconsistency and/or inadequacy of licensee safety evaluations may be widespread. A wide range of opinions seems to exist among licensees as to what constitutes an appropriate 10 CFR 50.59 safety evaluation, particularly for radwaste systems.

Therefore, discussion and guidance are provided for licensee use in preparing future 10 CFR 50.59 safety evaluations to support changes in the design and/or operation of the radioactive waste treatment systems of licensed facilities.

Although the detailed discussions of this guidance document are specifically directed to radioactive waste systems, the general principles and philosophy of the 10 CFR 50.59 safety evaluation guidance are also applicable to facility design and operation as a whole; thus, the application of 10 CFR 50.59 should reflect a consistent approach.

Regulatory references: 10 CFR 50.59, Regulatory Guide 1.21, Final Safety Analysis Report

Subject codes: 5.0, 9.0

Applicability: Reactors