Presented at the 2007 RETS/REMP Workshop

J. Stewart Bland, CHPChesapeake Nuclear Services, Inc.

Annapolis, MD 410-266-9174

jsbland@chesnuc.com

June 27, 2007

Co-Authors:◦ Val Malafeew, Chesapeake Nuclear Services, Inc.◦ Mike Kennedy and Scott Newberry

ISL, Inc., Rockville, MD

Not being presented on behalf of NRC; Information presented does not necessarily represent NRC’s positions.

Issued July 21, 1997 (Federal Register, Vol. 62, page 39082).

• A licensing requirement contained within 10 CFR 20, Subpart E, Radiological Criteria for License Termination.

• Applies to new licensees only; however a rule change is under consideration by NRC to extend (at least portions) to all operating licensees.

“Applicants for licenses, other than renewals, after August 20, 1997, shall describe in the application how facility design and procedures for operation will minimize, to the extent practicable, contamination of the facility and the environment, facilitate eventual decommissioning, and minimize, to the extent practicable, the generation of radioactive waste.”

• A licensing requirement contained within 10 CFR 20, Subpart E, Radiological Criteria for License Termination.

• Applies to new licensees only; however a rule change is under consideration to make applicable to all licensees.

• The intent of 10 CFR 20.1406 is to diminish the occurrence and severity of “legacy sites” by taking measures that will reduce and control contamination and facilitate eventual decommissioning.

• Supplementary Information of the Part 20, Subpart E rule pertaining to the §20.1406 provision (July 21, 1997 Federal Register, Vol. 62, page 39082), “Specific minimization requirements contained in the proposed rule are directed towards those making application for a new license because it is more likely that consideration of design and operational aspects that would reduce dose and minimize waste can be cost-effective when compared to such considerations during the license renewal stage where the existing design and previous operations may be major constraints.”

• To facilitate the licensing of new power plants, the NRC staff is preparing guidance for the implementation of 10 CFR 20.1406 before the fall of 2007, when it expects the first license application.

• The purpose of the Guide will be to present guidance that should be considered by license applicants in facility design and operating programs and procedures that would effectively implement this licensing requirement.

• Prevent - unintended release,

• Detect - early detection if there is unintended release of radioactive contamination, and

• Correct - unintended release of radioactive contamination by prompt and aggressive action.

• Contamination of the facility can be minimized with system designs that limit leakage and/or control the spread of contamination and with operational procedures that provide for early detection and follow-up mitigative and corrective measures.

• Prevention - Design - Inspection / maintenance

• Detection

• Correction

• A maintenance and inspection program should be applied to radioactive SSC that have a potential for leakage. • A leak identification program should be developed

to prevent unnecessary contamination and minimize radioactive waste.

• Interfaces between the radioactive SSC important to radiological safety and the non radioactive SSC should be minimized. • Interfaces should have a minimum of two barriers,

including one that can be a pressure differential.

• Temporary and/or mobile systems should be designed and interfaced with permanent plant systems in a manner that meets the original design considerations for meeting the requirements of 20.1406. • Potentially radioactive lines should use self-sealing

quick disconnects as well as the means to promptly isolate leaks.

• Operational interlocks should be incorporated to minimize the possibility of leakage and contamination.

• Design should ensure that spills and leaks from skid mounted systems will be contained and routed to radioactive waste drains.

• In areas subject to potential contamination, concrete floors, walls, and associated expansion joints should be sealed. • Seals should be maintained and integrity routinely

inspected to ensure that spills and leaks on the floors do not enter unmonitored areas beneath the floors and foundations.

• Systems that could contain very-low levels of contamination (e.g., below detection levels) should not be routed/processed by non-radioactive systems that concentrate contaminants. • Consider routing locker rooms and personnel showers to

radwaste processing or discharge; prevent reconcentration of radioactive materials in sewage plants.

• A program should be developed for maintaining control over storage and use of radioactive materials in areas outside the plant environs. Administrative controls such as standard operating procedures can be effective in preventing the spread of contamination when radioactive material or contaminated equipment must be transported from one station location to another and when the route of transport through lower radiation zones or "clean" areas cannot be avoided.

• A maintenance and inspection program should be applied to radioactive SSC that have a potential for leakage of radioactive material to the site environs, that is, on-site and off-site locations outside of the facility SSCs.

• Seals should be maintained over the life of the facility, and their integrity should be routinely inspected.

• Ventilation systems should be periodically checked to insure that the system continues to be adequate for controlling contamination.

• A leak identification program should be developed for components containing radioactive materials to prevent unnecessary contamination of equipment and surrounding areas and to minimize radioactive waste.

• Leak detection systems should be provided with the capability of detecting and quantifying small leakage rates (e.g., several gallons per week) from each zone.

• Contamination of the environment can be minimized by:• Prevent: system design features with routine

inspection and maintenance.• Detect: operational procedures that provide for

routine inspection and leak detection evaluations.• Correct: promptly control unintended

releases/system leaks to the environment. Evalauate consequences and institute appropriate remediation activities

• A conceptual site model (CSM) based on site characteristics and facility design will assist in: (1) understanding site performance, and (2) planning for corrective measures

• Applicants should:• Identify potential release mechanisms and possible

locations of contaminant releases

• Develop CSM of ground-water system and identify potential contamination pathways

• Assess site changes due to construction

• Systems containing radioactive materials should have double boundaries to the environment, have inspection capabilities, be part of a routine maintenance program (e.g., seals), and undergo periodic verification of integrity.

• If systems containing radioactive material do not have two impermeable boundaries to the environment, the applicant should propose specific environmental monitoring (e.g., sampling of ground water in close proximity to potential sources) to periodically verify integrity of the system ).

• Licensees should implement specific environmental monitoring for likely sources and an overall on-site environmental monitoring for overall site verification.

• Licensees should implement specific environmental monitoring for likely sources and an overall on-site environmental monitoring for overall site verification.

• Proposed monitoring programs should allow for re-evaluation of the location of monitoring sensors and sampling frequency if contaminants are detected. This analysis should provide the technical basis for determining the need for further action.

• Exterior tanks should be located on or above bermed concrete pads, which should be lined or sealed with an impermeable membrane. Each bermed area should have provisions for sampling and release of rainwater.

• Use sills at ingress/egress points of rooms or buildings. containing radioactive systems to prevent leakage/seepage to the outside.

• If foundation drains are used as part of a building design, the capability for sampling and processing the effluent of those drains also should be included.

• Backfill should not contain soil that contains concentrations of radioactive material above the naturally occurring levels.

• Potential leakage from any existing adjoining nuclear facility should be prevented from migrating into the excavation and backfill of a new nuclear facility.

• In the event of leakage from the facility to the environment, the design of excavations and selection of backfill should facilitate the migration of contaminants to designated systems of the facility (e.g., radioactive external waste drains or sumps) for eventual extraction and treatment.

• If contamination is detected, the conceptual site model and monitoring information should be used to develop event specific models of contaminant migration before the selection of a remediation strategy.

• Licensees should keep good plant records and establish a program to ensure adequate and complete documentation of corporate knowledge and operational events beyond those required by the NRC in 10 CFR 50.75(g). • Assist in preparing a good historical assessment

of a nuclear facility. • Adequate historical assessment can save time

and effort during decommissioning planning.

• Information relating to the facility design, facility construction, onsite waste disposal, onsite contamination, and results of monitoring should be centrally located and readily recoverable.

• Records should include global positioning system readings that pinpoint all buried component locations, particularly components in the site environs.

Temporary piping installed during construction should be removed to avoid undocumented random piping in the field that, when uncovered, will raise questions about the extent of site contamination during decommissioning.

Construction debris should not be disposed of within the controlled area.

Volume reduction should be considered for minimizing the volume of generated waste, consistent with ANS-40.35-1991, “Volume Reduction of Low Level Radioactive Waste or Mixed Waste.”

Waste streams with significantly different levels of contamination should not be mixed in order to minimize the volume of the higher-activity wastes.

Release of the draft Regulatory Guide for public comment is expected in July, 2007

Public comment period – 90 days

Final guide expected in January, 2008

NEI concerns expressed at ACNW Meeting◦ Need to emphasize objectives and systematic

process. ◦ Don’t use RG as a checklist; have a separate

NUREG. ◦

Need overall philosophy/criteria◦ What’s enough, how do you know when you are

there?

Rule specifies: “minimize, to the extent practicable, contamination of the facility and the environment, facilitate eventual decommissioning, and minimize, to the extent practicable, the generation of radioactive waste.” ◦ No balancing of costs and benefit have been evaluated or

included. ◦ This could be different than a “reasonably achievable”

approach.

Clear integration with current program and requirements.◦ Standard Radioactive System Design Req’ts (RG 1.143)◦ Maintenance Rule◦ §50.59 process◦ §50.75g documentation