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Exelon Generation Company, LLC; Braidwood Station, Units 1 and 2, and Byron Station, Unit Nos. 1 and 2

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Nuclear Regulatory Commission.


10 CFR 2.206 request; receipt.


The U.S. Nuclear Regulatory Commission (NRC) is giving notice that by petition dated February 8, 2017, Barry Quigley (the petitioner) has requested that the NRC take action with regard to Braidwood Station, Units 1 and 2, and Byron Station, Unit Nos. 1 and 2. The petitioner's requests are included in the SUPPLEMENTARY INFORMATION section of this document.


July 27, 2017.


Please refer to Docket ID NRC-2017-0167 when contacting the NRC about the availability of information regarding this document. You may obtain publicly-available information related to this document using any of the following methods:

  • Federal Rulemaking Web site: Go to and search for Docket ID NRC-2017-0167. Address questions about NRC dockets to Carol Gallagher; telephone: 301-415-3463; email: For technical questions, contact the individual listed in the FOR FURTHER INFORMATION CONTACT section of this document.
  • NRC's Agencywide Documents Access and Management System (ADAMS): You may obtain publicly-available documents online in the ADAMS Public Documents collection at​reading-rm/​adams.html. To begin the search, select “ADAMS Public Documents” and then select “Begin Web-based ADAMS Search.” For problems with ADAMS, please contact the NRC's Public Document Room (PDR) reference staff at 1-800-397-4209, 301-415-4737, or by email to The ADAMS accession number for each document referenced (if it is available in ADAMS) is provided the first time that it is mentioned in this document.
  • NRC's PDR: You may examine and purchase copies of public documents at the NRC's PDR, Room O1-F21, One White Flint North, 11555 Rockville Pike, Rockville, Maryland 20852.
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Joel S. Wiebe, Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001; telephone: 301-415-6606, email:

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On February 8, 2017, the petitioner requested that the NRC take action with regard to Braidwood Station, Units 1 and 2, and Byron Station, Unit Nos. 1 and 2 (ADAMS Accession No. ML17061A127). The petitioner requested: (1) Issue a violation under part 50 of title 10 of the Code of Federal Regulations (10 CFR), appendix B, Criterion III, Design Control for deficiencies in the analysis of record (AOR) for the main steam isolation valve (MSIV) room pressurization following a high energy line break (HELB), (2) Issue a violation under 10 CFR part 50, appendix B, Criterion XVI, Corrective Action, for failure to update the AOR in a timely manner, (3) Require Exelon (the licensee) to show that the consequences of the secondary missiles resulting from MSIV room pressurization do not have adverse consequences, (4) Issue a demand for information under 10 CFR 2.204, “Demand for information,” to compare and contrast the behavior of Exelon management described in the petition with the NRC's policy statement on the attributes of a safety-conscious work environment, and (5) Use Exelon's response to number 4, above, on which to determine whether to issue a “chilling effects” letter.

As the basis for this request, the petitioner states that: (1) Break enthalpies used in the MSIV room pressurization AOR are actually the thermodynamic internal energy of the steam, not the enthalpy. Since in the range of interest, the internal energy is about 13 percent less than the enthalpy, the energy flow to the areas of concern is non-conservative. Steam flow from secondary piping is neglected; (2) Corrective actions to resolve an issue in the AOR are long overdue (8 years) and improperly tracked; (3) A proposed revision to the AOR shows that the MSIV room roof slabs will be ejected by the high pressures in the MSIV rooms becoming potential missiles; and (4) Management dismissed information in the Updated Final Safety Evaluation Report (UFSAR) that supported the concerns about the AOR as “excessive detail” and directed personnel to remove the information. Management dismissed UFSAR internal inconsistency related to the “Break Exclusion Zone” without discussion or review and stated that the information supporting the concern could be deleted as an UFSAR cleanup item. Recently, there was an operability concern where engineering management maintained a Start Printed Page 34994position of operability in the face of conflicting information. The information that engineering management relied on to support operability was demonstrably irrelevant.

The request, except for the petitioner's item 3, which does not request enforcement action, is being treated pursuant to 10 CFR 2.206 of the Commission's regulations. The request has been referred to the Director of the Office of Nuclear Reactor Regulation. As provided by 10 CFR 2.206, appropriate action will be taken on this petition within a reasonable time. The petitioner met with the Petition Review Board (PRB) on April 13, 2017, to discuss the petition; the transcript of that meeting is an additional supplement to the petition (ADAMS Accession No. ML17111A774). On June 12, 2017, the petition manager informed the petitioner that the PRB accepted the petition items 1, 2, 4, and 5 for review under 10 CFR 2.206.

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Dated at Rockville, Maryland, this 20th day of July, 2017.

For the Nuclear Regulatory Commission.

Brian E. Holian,

Acting Director, Office of Nuclear Reactor Regulation.

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[FR Doc. 2017-15859 Filed 7-26-17; 8:45 am]