Updates to NRC’s Consolidated NMSS Decom

Kristina L. Banovac, Robert L. Johnson, Duane W. Schmidt, and Theodore B. Smith: U.S. Nuclear Regulator

GUIDANCE TOPICS IN

DRAFT SUPPLEMENT 1 TO NUREG-1757

Restricted Use and Institutional Controls:• LTR’s risk-informed, graded approach for ICs• Two new IC options, with NRC long-term oversight:

• LTC license: possession-only license, license conditions note restrictions on 

site use and necessary monitoring, maintenance, or reporting

• LA/RC: legal agreement between NRC and licensee, LA requires licensee to 

record restrictive covenant, describing restrictions on site use, with legal recordation body

• Total system approach to sustain site protection at restricted use sitesEngineered Barriers:• Risk-informed graded approach to EBs • EB analysis process and technical basis for EB performance

• Potential performance and degradation mechanisms• Example of erosion protectionRealistic Scenarios:• Selection and justification of exposure scenarios based on reasonably 

foreseeable future land use - land uses likely within the next 100 years, considering land use trends and plans

• Unlikely scenarios are evaluated to risk-inform the decisionOnsite Disposal of Radioactive Material:• Onsite disposal under 10 CFR 20.2002 acceptable if resulting dose:

• “few millirem” per year• 100 mrem/yr with additional financial assurance to decommission disposal• 25 mrem/yr for short-lived materials, license termination not imminent

Intentional Mixing:• Acceptable to meet waste acceptance criteria of off-site disposal facilities 

(current practice)

• Acceptable to meet LTR criteria if:

• Part of an overall approach that is ALARA• Area containing mixed soil is no greater than original contamination footprint• No uncontaminated soil from outside footprint, except in cases where it is 

the only viable alternative to meeting LTR criteria

Removal of Material After License Termination:• Clarifies what building-related materials may remain onsite at license termination

• Acceptable approaches:

• Materials meet previously approved (offsite) release criteria

• For volumetric contamination: potential dose from off-site uses is less than 

“few millirem” per year

• Bare building structures result in dose that meets LTR criteria

LA/RC Legal Agreement with 

Restrictive Covenant 

EB Engineered BarrierIC Institutional Control

LTR License Termination Rule 

(10 CFR 20, Subpart E)

LTC Long Term Control (license)

ACRONYMS

GOALS and BENEFITS 

• Risk-inform decommissioning 

program to enhance safety and efficiency

• Return existing sites to beneficial reuse in timely manner• Prevent future legacy sites• Inform and involve stakeholders• Provide more flexibility to licensees• Continuously improve the 

decommissioning program

Restricted 

Use

and 

Institutional Controls

Engineered

Barriers

Onsite Disposal of

Radioactive Material

Realistic

Scenarios

Intentional

Mixing

Removal of

Material

After Termination

NRC IC

options

as

a “last resort” Sustaining

future

ownership

EBs typically

used for

restricted use

EB degradation 

analyzed

must be 

Scenario

timeframe

Resident farmer

not necessarily

the default

Legacy site concern

with onsite disposal

Conditions for intentional

mixing for LTR compliance

When

to

evaluate

off-site

exposure

scenarios

GUIDANCE 

TOPICS

CHALLENGES

http://www.nrc.gov/what-we-do/regulatory/decommissioning/reg-guides-comm.html