ML18101A008
| ML18101A008 | |
| Person / Time | |
|---|---|
| Issue date: | 04/11/2018 |
| From: | Tripp C Programmatic Oversight and Regional Support Branch |
| To: | |
| Duvigneaud D | |
| Shared Package | |
| ML18100B106 | List: |
| References | |
| IN 2018-005 | |
| Download: ML18101A008 (7) | |
Text
INFORMATION NOTICE 2018-05 LONG-TERM FISSILE MATERIAL ACCUMULATION DUE TO UNANALYZED OR IMPROPERLY ANALYZED CONDITIONS AT FUEL CYCLE FACILITIES Christopher Tripp, Ph.D., Senior Nuclear Process Engineer Programmatic Oversight & Regional Support Branch Division of Fuel Cycle Safety, Safeguards, and Environmental Review
OVERVIEW ADDRESSEES DESCIPTION OF CIRCUMSTANCES REGULATORY BACKGROUND DISCUSSION 2
ADDRESSEES Facilities licensed under:
Title 10 of the Code of Federal Regulations (10 CFR)
Part 70, Domestic licensing of special nuclear material Holders or applicants of a construction permit or operating license for production facilities, including the production of medical isotopes.
10 CFR Part 40, Domestic licensing of source material (no criticality hazards but may be useful) 3
DESCRIPTION OF CIRCUMSTANCES NRC staff identified recent operating experience involving unanticipated, long-term accumulation of fissile material in uncontrolled geometry systems due to improper analysis of credible plant conditions.
- July 2017 - unexpected fissile material in desiccant filters
- Unexpected fissile solution in a junction box
- Catch tray piles that exceeded height limits
- Accumulation of fissile material in excess of established criticality safety limits in a scrubber 4
REGULATORY BACKGROUND Subpart H of 10 CFR Part 70 10 CFR 70.61(b) requires that the risk of each credible high consequence event be limited such that its likelihood of occurrence is highly unlikely.
10 CFR 70.61(d) requires that the risk of nuclear criticality accidents be limited by assuring that all nuclear processes will be subcritical under both normal and credible abnormal conditions.
5
DISCUSSION Regulatory requirements necessitate that, through the ISA, a licensee evaluates all credible pathways that could potentially lead to a consequence of concern.
Licensees encouraged to consider:
- credible events or conditions whose likelihood has either been underestimated or not considered; and
- analysis for areas perceived as low risk, which have no controls applied, may have unchallenged or unverified assumptions.
6
QUESTIONS?
7