ML23157A042

2022 Monticello End-of-Cycle Meeting Presentation

ML23157A042
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Site:	Monticello
Issue date:	06/06/2023
From:	NRC/RGN-III/DORS/RPB3
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ML23013A315	List: IR 05000263/2022006 ML23111A228 ML23111A276 ML23157A042 ML23157A043
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Nuclear Regulatory Commission Region III, Lisle, IL.

2022 End of Cycle Annual Assessment Webinar Monticello Nuclear Generating Plant

During the presentation, microphones will be muted, and cameras turned off.

2022 Annual Assessment Webinar Monticello Nuclear Generating Plant For the Q&A Session:

Raise your hand under Reaction on the Teams app Press *5 to raise / lower hand if you are a dial-in caller Email your questions after the Webinar to the PAOs

NRC Regional Staff Hironori Peterson Branch Chief Division of Operating Reactor Safety, Branch 3 Roy Elliott Senior Project Engineer Division of Operating Reactor Safety, Branch 3 3

Agenda

• Presentation

-NRC Mission

-Reactor Oversight Process (ROP)

-2022 Safety Performance Overview

-Control of Radiological Effluents

• Question-and-Answer Session 4

To license and regulate the nations civilian use of radioactive materials to provide reasonable assurance of adequate protection of public health and safety and to promote the common defense and security and protect the environment.

OUR MISSION Region III Office, Lisle, IL 5

How do we meet our Mission?

Licensing Oversight (Inspections)

Enforcement Incident Response Regional Inspector Ashley Demeter at Monticello Resident Inspector Tom McGowan at Monticello NRC Emergency Operations Center 6

So how did the site do?

Monticello 7

Monticello Resident Inspectors Chuck Norton Senior Resident Inspector Tom McGowan Resident Inspector 8

Reactor Oversight Process www.nrc.gov/reactors/operating/oversight.html 9

Action Matrix Columns Increasing:

Safety Significance Inspection Management Involvement Regulatory Action Licensee

Response

Regulatory

Response

Degraded Performance Multiple/Repetitive Degraded Cornerstone Unacceptable Performance www.nrc.gov/reactors/operating/oversight.html 10

Operated safely and in a manner that preserved the public health and safety and protected the environment Licensee Response Column 2225 hours0.0258 days <br />0.618 hours <br />0.00368 weeks <br />8.466125e-4 months <br /> of direct inspection All Green Performance Indicators One Green Findings with Associated Non-cited Violations Failure to Maintain FLEX Equipment Consistent with the Requirements of 10 CFR 50.155(c)(2)

One Green Security Finding with Associated Non-cited Violation https://www.nrc.gov/reactors/operating/oversight/listofasmrpt.html Monticello 2022 Assessment Summary 11

12 Control of Radiological Effluents

Overview

• Nuclear power plants need to discharge radioactive effluents in small amounts in order to operate and have been doing so safely since initial start-up

• Rules limit the amount that can be released to ensure they are a fraction of what is received from background sources

• Release information is publicly available and inspected by the NRC 13

• A measurement of the energy imparted by radiation

• Conventional units used are mrem (millirem)

• Can be thought of as the overall risk from radiation to a person

• Average dose an individual receives per year from natural sources of radiation (sun, soil, etc.) is about 300 mrem 14 Dose

• Focus on limiting the dose to people living around the site

• Nuclear power plants must limit dose to the public to 25 mrem/year

• Plants are designed to operate well below 25 mrem/year

• Monticello typically runs with the maximum dose to a member of the public below 0.1 mrem/year 15 Regulations

16 Public Health

& Safety Land Use Census Effluent Controls REMP GPI

Land Use Census

• How the public is exposed to radiation depends on how the land around the plant is used

• Plants annually perform a census to identify changes in how the land is used

• Looks for things such as large gardens, dairy cows, where residents are located, etc.

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18 Public Health

& Safety Land Use Census Effluent Controls REMP GPI

Effluent Controls

• We are using effluent as a generic term to describe radioactive material released from the site in gaseous or liquid form

• Effluent controls ensure that what is being released is monitored and controlled to ensure dose limits are met 19

Effluent Controls

• Doses to the public are too small to measure directly

• Sites sample and analyze effluents from the plant piping or tanks they are being released from

• Information from the land use census used to model how an individual would be exposed to the effluent release

• Doses are calculated based on the model 20

21 Effluent Controls

22 Public Health

& Safety Land Use Census Effluent Controls REMP GPI

• Measures radiation in the environment during the lifetime of the plant

• Determines if any measurable levels of radiation are from plant operation

• Determines if results are commensurate with the radioactive effluents 23 REMP Radiological Environmental Monitoring Program

24 REMP

25 Public Health

& Safety Land Use Census Effluent Controls REMP GPI

• Objectives include

• Provide timely detection and effective response to inadvertent on-site releases to groundwater in order to prevent migration off-site and to quantify impacts on decommissioning

• Improve communication with external stakeholders

• Perform program oversight to ensure effective implementation 26 GPI Groundwater Protection Initiative

• Site hydrology

- How does the groundwater move?

• Risk ranking

- Where is there potential for leaks?

• Groundwater monitoring

- Monitoring wells established in strategic locations based on hydrology and risk ranking

• Recovery

- Pumping contaminated water out of the ground for appropriate handling

• Communications

- Protocols established between site and State/Local governments 27 GPI

28 GPI

• November 2022

- Site identified elevated tritium levels in one of the GPI monitoring wells during routine monthly sampling

- Site notified the State and NRC of the elevated levels

- Sampling frequencies of nearby monitoring wells increased

- Site started investigation to determine source of the leak 29 Recent Tritium Leak

• December 2022

- Site identified source of leak in pipe that runs between the reactor and turbine buildings, which have a small gap between them.

- Leak was captured and rerouted back into the plant

- Site started recovering contaminated groundwater

• Stored in tanks on-site and reused as plant make-up water

- Site started installing additional monitoring wells 30 Recent Tritium Leak

• March 2023

- Routine sampling of monitoring well indicated some of the leak was again making it to groundwater

- Site shut down the plant to replace the section of pipe

• Permanent repair was originally planned for the routine maintenance outage scheduled in April 2023 31 Recent Tritium Leak

• Ongoing

- Site continues to monitor location of tritium

- Monitoring well sample frequency adjusted for each well based on current conditions

- Evaluation for additional monitoring wells continues

- Recovery of contaminated groundwater routinely adjusted for current conditions

- Sites actions are aimed at preventing uncontrolled migration of the tritium off-site 32 Recent Tritium Leak

• Risk from off-site release

- The amount of tritium leaked to the groundwater would not pose a health concern even if all of it reached the Mississippi River

- Dose to a member of the public would be well below 1 mrem

• Remember, 300 mrem/year from natural sources 33 Recent Tritium Leak

• Even though there is no health concern, it does not mean it is okay to do nothing

- NRC expects effluents to be released in a monitored and controlled fashion

- Site had to identify and stop the leak

- Recovery of contaminated groundwater to mitigate off-site release through groundwater is expected

- Extensive monitoring of the groundwater will ensure that any off-site release through the groundwater is appropriately accounted for

- NRC will verify appropriate control 34 Recent Tritium Leak

• The NRC has specialized inspectors perform periodic on-site inspections of the programs discussed today

• The NRC maintains at least two resident inspectors at each site to oversee the day-to-day operation of the site

• NRC will continue to follow the sites actions through the routine inspection program 35 Inspections

36 Land Use Census

- Review implementation and results Effluent Controls

- Observe routine effluent sampling and analysis

- Walkdown effluent systems and radiation monitoring equipment

- Review maintenance and calibration records

- Review quality assurance programs

- Review discharges GPI

- Walkdown and observe GPI program elements

- Review monitoring well results and licensee evaluations of results REMP

- Observe sampling activities

- Review laboratory results and licensee evaluation of results

- Review quality assurance programs Inspections

Nuclear power plants are required to submit annual reports summarizing effluent releases, on-site groundwater monitoring results, and REMP results.

37 Annual Reports https://www.nrc.gov/reacto rs/operating/ops-experience/tritium/plant-info.html These reports can be found at

For more information Inspection Reports

- https://www.nrc.gov/reactors/operating/oversight/listofrpts-body.html Reactor Oversight Process

- https://www.nrc.gov/reactors/operating/oversight.html Fact Sheets and Brochures

- https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/

NRC Information Digest

- https://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1350/

Regulations

- https://www.nrc.gov/reading-rm/doc-collections/cfr/

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NRC Social Media Channels Facebook: https://www.facebook.com/nrcgov/

Twitter: https://twitter.com/nrcgov YouTube: http://www.youtube.com/user/NRCgov Linkedin: https://www.linkedin.com/company/u-s--nuclear-regulatory-commission/

Flickr: https://www.flickr.com/photos/nrcgov/

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Meeting Feedback On Any Device or Computer:

Go to the Public Meeting Schedule at (www.nrc.gov/pmns/mtg?do=recent30days)

Locate this meeting using the sorting buttons and click on the Meeting Feedback Form Link.

Note: Meetings are sorted by date and time. Use last to get to the most recently completed meeting.

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Region III Public Affairs Officers Viktoria Mitlyng Office: 630-829-9662 Cell: 630-201-1345 Viktoria.mitlyng@nrc.gov Prema Chandrathil Office: 630-829-9663 Cell: 630-515-6145 Prema.chandrathil@nrc.gov 41

QUESTIONS?

To ask a question either:

Raise your hand under Reaction on the Teams app Press *5 to raise / lower hand if you are a dial-in caller.

Email your questions after the Webinar to the PAOs.

viktoria.mitlyng@nrc.gov prema.chandrathil@nrc.gov 42

This Concludes the 2022 End of Cycle Annual Assessment Webinar Presentation for Monticello Nuclear Generating Plant Thank You & Goodnight