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NEI Presentation: Micro-Reactors Regulatory Topics
	ML19294A182
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Site:	Nuclear Energy Institute
Issue date:	10/17/2019
From:	; Nuclear Energy Institute
To:	; Office of Nuclear Reactor Regulation
	Hoellman J,NRR/DANU/UARP,415-5481
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Micro-Reactors Regulatory Topics Marc Nichol, Director New Reactor Deployment October 17, 2019

Overview of Micro-Reactors Typically 1 MWe to 10 MWe (2 MWth to 40 MWth)

Very small size

Site as small as 0.1 acres, building ~size of a house

Reactor is road shippable, minimal site work Non-traditional uses and locations

Remote villages (e.g., arctic and islands)

Mining operations

Defense and other mission critical installations

Micro-grids - in populated areas Rapidly maturing technology

First licensing applications expected in 2020

Intended Micro-Reactor Capabilities*

Resilience - ability to withstand, mitigate or quickly recover from

Extreme natural events

Man-made physical and cyber threats

Electro-magnetic pulses Operations

Island mode and black-start

Automatic operations with minimal or no operator action required

Flexible operation - e.g., integration with renewables

Hybrid energy - (e.g., electricity, heat, hydrogen, water desalination/purification)

General description, all capabilities may not be applicable to all designs ©2019 Nuclear Energy Institute 3

Micro-Reactor Safety Features*

Very small potential consequences

Radionuclide inventory significantly lower than large LWRs

Fail-safe, shuts itself off, long term passive cooling

No credible event that could result in unacceptable off-site doses Features that result in very low potential consequences

Safety relies on passive or inherent functions (natural forces)

Reactor can be contained completely below ground

Natural forces sufficient to transfer decay heat indefinitely without damaging fuel

Proliferation resistant fuel and enrichments below 20% U-235

Safety does not rely on any operator action

Operational simplicity: very few instruments and controls

General description, all features may not be applicable to all designs ©2019 Nuclear Energy Institute 4

Micro-Reactor Regulatory Considerations Safety profile of micro-reactors fundamentally differ from other power reactors

Existing regulations and proposed rule changes are often not well suited to micro-reactors (e.g., Security, Aircraft Impact, some GDC)

Near term should look at using alternative approaches or exemptions, but in future rulemaking could facilitate more efficient micro-reactor licensing Micro-reactors are more similar to research and test reactors (RTR)

Similar in power level and potential consequences Some differences between micro-reactors and RTRs

Micro-reactors typically operate nearly constantly at full power, have balance of plant

Micro-reactors have more inherent safety features (e.g., loss of coolant and loss of electrical power may not be relevant accidents)

Micro-reactors rely less on human actions

RTRs can be open pool, typically perform tests and experiments

Framing the Regulation of Micro-Reactors NUREG-1537 is a more appropriate guidance document

Use as starting point, adjust based on features of micro-reactors

Accommodate different approaches (e.g., MCA, MHA, LMP)

Dose criteria for accidents from 50.34(a)(1) / 100.11

NRC recent success in adapting to other technologies (e.g., SHINE)

Minimum amount of regulationto protect public health and safety

Policy of Section 104c 42 USC 2134c

Embodied in NRC Principles of Good Regulation Additional considerations

Performance based, consequence oriented

Graded approach to address differences in designs

Micro-Reactor Regulatory Issues Priority Issues Addressed in Broader Other Potential Issues Efforts

1. Review Scope, Duration,

Siting

Annual Licensee Fees Level of Effort

Environmental Reviews

Generic License

2. Operations (auto/remote)

Fuel Qualification

PRA

3. Inspections

QA

4. Physical Security

Liability Insurance

5. Emergency

Decommissioning Funding Preparedness

Transportation

6. Aircraft Impact

Review Scope, Duration, Level of Effort Schedule and cost related to complexity and safety margin Notional Micro-reactor Typical Reactor Manhours to develop design to maturity ~ <25,000 to 50,000 ~1 million needed for NRC review Number of pages in an application ~ <500 to 1,000 ~10,000 Number of pages in supporting documents ~ <1,000 to 2,000 ~50,000 Recommended NRC targets for micro-reactor review (including environmental)

Schedule: 6 to 12 months (from Acceptance to Final Safety Evaluation)

Cost: $2M to $5M, roughly 7,000 to 18,000 man hours

Automatic / Remote Operations*

Features of micro-reactors with automatic / remote operations

Will not require human actions to maintain safety

May not require human action for power adjustment, shutdown, or startup

Have very few controls Applicant evaluation to determine whether there is need for operator actions

Exemptions from Part 50.54 and Part 55 may be needed If no human action needed to protect public health and safety

No licensed operators required (numbers, presence, training, requal, simulator)

Plant is likely to have at least one individual on-site or remote to monitor reactor If some actions needed to protect public health and safety

Applicant propose licensed operator scheme (number, presence, training)

Ability to return within an acceptable time could be credited for presence

Assumes that requirements for licensing automatic/remote operations are adequate ©2019 Nuclear Energy Institute 9

Instrumentation and Controls Traditional control room may not be necessary If safety can be assured without operator action, and if unauthorized individual cannot compromise safety through manipulating controls:

No need for requirements relating to the control room (e.g., GDC-19)

No need to require capability for operator initiated shutdown

No need for instruments and controls to be in a restricted area

NRC Inspection and Oversight Licensee is responsible for safety and regulatory compliance NRC independently verifies licensees compliance through inspection

Performance based, focused on activities important to safety

Emphasis on observing activities over reviewing documents Micro-reactors have very few activities Recommended NRC inspection paradigm

Inspection frequency - once every one or two years

No need or requirement for resident inspectors

Construction inspection program emphasize manufacturing/supplier inspections

Significance determination process and performance indicators not needed Need for NRC inspection manual and procedures for micro-reactors

Model after IMC-2545 and related procedures (for RTR)

Screen out irrelevant procedures (e.g., IP-69005 on experiments)

Emergency Preparedness EP rulemaking for SMRs and other nuclear technologies

Performance based, technology inclusive, consequence oriented

Do no explicitly refer to micro-reactors Draft rule 10 CFR 50.60

Appears flexible enough for micro-reactors DG-1530

Does not contemplate extremely low potential consequences of micro-reactors Need guidance on emergency plans for micro-reactors

Model after NUREG-0849 (for RTRs)

Physical Security Security rulemaking for SMRs and other nuclear technologies

Not very performance based, technology inclusive, consequence oriented

Results in excessive burden on micro-reactors Requirements appropriate for micro-reactor security

Principally focused on theft and diversion

Access control

Intrusion detection

Communications with law enforcement

Human actions are not needed to meet security requirements

If personnel perform security function, may be outside site boundary, have other duties, be unarmed

Aircraft Impact Assessment Impact of large aircraft is beyond-design-basis-event

Requirements on design, construction, testing, ops and maintenance for design-basis events do not apply Aircraft impact on micro-reactors are highly unlikely

Not high-value target: could not cause mass casualties

Not easily impacted: building is small in size, some may be below grade

Impact does not pose hazard to public: very little radionuclide inventory Micro-reactors do not need to meet Part 50.150 requirements

Reactor core remaining cool, or containment remaining intact, and

Maintaining spent fuel cooling or spent fuel pool integrity;

Not needed to protect public health and safety

Potential Generic Acceptance Criteria Do not rely on any active functions from systems or components to remain functional during or following a design basis event to prevent or mitigate the consequences of accidents that could result in the potential offsite exposures comparable to the applicable guideline exposures set for in 10 CFR 50.34(a)(1) or 10 CFR 100.11.

Micro-reactors that meet acceptance criteria can

Apply an adjusted NUREG-1537 approach

Apply approaches for key micro-reactor policy and technical issues

Conclusions First micro-reactor application expected in 2020 NUREG-1537 is appropriate starting point for guidance for micro-reactors

Micro-reactors are similar to RTRs in terms of power level and potential consequences

Differences in operations and safety features should be considered Key Policy and Technical issues to address promptly

Review duration and level of effort

Automatic / remote operations

NRC Inspection

Emergency Preparedness

Physical Security

Aircraft Impact

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