May 14, 2014

Mr. Adam C. Heflin, President and Chief Executive Officer Wolf Creek Nuclear Operating Corporation P.O. Box 411 Burlington, KS 66839

SUBJECT: SUMMARY OF PUBLIC MEETING TO DISCUSS AN APPARENT VIOLATION

IDENTIFIED AT WOLF CREEK GENERATING STATION

Dear Mr. Heflin,

On April 30, 2014, members of the U.S. Nuclear Regulatory Commission (NRC) staff met with representatives of Wolf Creek Nuclear Operating Corporation at the Region IV office in Arlington, Texas, to discuss an apparent violation identified at Wolf Creek Generating Station. The apparent violation concerned the accuracy of the licensee’s dose assessment software, and was discussed in NRC Inspection Report 05000482/2013502 (ADAMS ML14092A618). The licensee presented its perspective on the circumstances of the violation and the safety significance. The list of attendees and the licensee’s presentation is enclosed. In accordance with 10 CFR 2.390 of the NRC’s “Rules of Practice,” a copy of this letter will be made available electronically for public inspection in the NRC Public Document Room or from the NRC's Agencywide Documents Access and Management System (ADAMS), accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html.

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Sincerely,

/RA/ V.Gaddy for

Mark S. Haire, Chief Plant Support Branch 1 Division of Reactor Safety

Docket No. 50-482 License No. NPF-42 Enclosures: 1. List of Attendees 2. WCNOC Presentation Slides

UNITED STATES

NUCLEAR REGULATORY COMMISSION REGION IV

1600 E. LAMAR BLVD.

ARLINGTON, TX 76011-4511

A. Heflin - 2 -

Electronic distribution by RIV: Regional Administrator (Marc.Dapas@nrc.gov) Deputy Regional Administrator (Steven.Reynolds@nrc.gov) DRP Director (Kriss.Kennedy@nrc.gov) DRP Deputy Director (Troy.Pruett@nrc.gov) DRS Director (Anton.Vegel@nrc.gov) DRS Deputy Director (Jeff.Clark@nrc.gov) Senior Resident Inspector (Charles.Peabody@nrc.gov) Resident Inspector (Raja.Stroble@nrc.gov) WC Administrative Assistant (Carey.Spoon@nrc.gov) Branch Chief, DRP/B (Neil.OKeefe@nrc.gov) Senior Project Engineer, DRP/B (David.Proulx@nrc.gov) Project Engineer, DRP/B (David.You@nrc.gov) Public Affairs Officer (Victor.Dricks@nrc.gov) Public Affairs Officer (Lara.Uselding@nrc.gov) Project Manager (Randy.Hall@nrc.gov) Branch Chief, DRS/TSB (Geoffrey.Miller@nrc.gov) RITS Coordinator (Marisa.Herrera@nrc.gov) ACES (R4Enforcement.Resource@nrc.gov) Regional Counsel (Karla.Fuller@nrc.gov) Technical Support Assistant (Loretta.Williams@nrc.gov) Congressional Affairs Officer (Jenny.Weil@nrc.gov) RIV/ETA: OEDO (Joseph.Nick@nrc.gov)

DOCUMENT NAME: WC Mtg Sum 4-30-2014 ADAMS ACCESSION NUMBER:

SUNSI Review MSH By:

Non-Sensitive Sensitive

Publicly Available MSH Non-Publicly Available

Keyword:

OFFICE DRS/PSB1 DRP/PBB DRP/PBB DRS/PSB1 ACES DRP/CPBB DRS/CPSB1

NAME P. Elkmann C. Peabody D. Proulx G. Guerra R. Browder N. O’Keefe MHaire/VGaddy

SIGNATURE /RA/ /RA/ /RA/ /RA/ /RA/ /RA/ /RA/ DATE 5/6/14 5/8/14 5/6/14 5/8/14 5/7/14 5/7/14 5/9/14

OFFICIAL RECORD COPY

Enclosure 1

List of Attendees NRC Mr. S. Reynolds, Deputy Regional Administrator Ms. K. Fuller, Regional Counsel Mr. J. Clark, Acting Division Director, Division of Reactor Safety Mr. T. Pruett, Deputy Division Director, Division of Reactor Projects Mr. M. Haire, Branch Chief, Plant Support Branch 1, Division of Reactor Safety Mr. N. O’Keefe, Branch Chief, Branch B, Division of Reactor Projects Ms. V. Campbell, Branch Chief, Allegation and Enforcement Branch Mr. R. Kahler, Branch Chief, DPR, Office of Nuclear Security and Incident Response Mr. P. Elkmann, Senior Inspector, Plant Support Branch 1, Division of Reactor Safety Mr. C. Peabody, Senior Resident Inspector, Branch B, Division of Reactor Projects Mr. S. LaVie, Senior Specialist, DPR, Office of Nuclear Security and Incident Response Mr. D. Proulx, Senior Project Engineer, Branch B, Division of Reactor Projects Mr. J. Wray, Senior Enforcement Specialist, Office of Enforcement Mr. G. Guerra, Inspector, Plant Support Branch 1, Division of Reactor Safety Ms. R. Browder, Senior Enforcement Specialist, Allegation and Enforcement Branch Wolf Creek Nuclear Operating Corporation Mr. R. Smith, Chief Nuclear Officer Mr. M. Westman, Manager, Regulatory Affairs Mr. T. East, Superintendent, Emergency Planning Mr. W. Ketchum, Supervisor, Engineering Mr. W. Muilenburg, Supervisor, Licensing M. D. Michel, Instructor, Chemistry

Wolf Creek Nuclear Operating Corporation

Regulatory Conference Inspection Report 05000482/2013-502

Preliminary White Finding Enclosure 2

Wolf Creek Representatives

• Russell Smith – Site Vice President

• Mike Westman – Manager Regulatory Affairs

• Timothy East – Superintendent EP

• Bill Muilenburg – Supervisor Licensing

• Bill Ketchum – Supervisor Engineer

• Dan Michel – Instructor II Enclosure 2

NRC’s Preliminary finding

• An apparent violation of 10 CFR 50.54(q)(2) was identified involving the failure to maintain adequate methods for assessing the actual or potential consequences of a radiological emergency between September 2012 and November 2013, in accordance with the requirements of 10 CFR 50.47(b)(9).

• The inaccurate calculation was corrected on February 25, 2014.

• The inspectors determined the failure to maintain a Dose Assessment Process capable of providing a technically adequate estimate of offsite dose. This issue has been entered into the licensee’s corrective action system as Condition Report 2013-0076247.

Enclosure 2

Root Cause Evaluation Findings

• ROOT CAUSE - Information Systems (IS) procedures and guidance did not require comprehensive verification and validation for risk significant software.

• CONTRIBUTING CAUSE 1 - Less than adequate EP oversight of risk significant drill-identified issues.

• Also determined the EDCP Containment Spray Filtration Toggle was not functional.

• Determined the EDCP deficiencies were introduced with Version 3.6 issued in February 2003.

Enclosure 2

Key Corrective Actions

• Improve Emergency Planning ownership of risk significant issues.

• Improve Computer Software verification and validation (V&V).

• EDCP was corrected and issued February 25, 2014 including both filter factor and containment spray toggles.

Enclosure 2

EDCP

Field Team Data 11Other Event Trees

Calculated Value

SGTR Rad Mon

Unit Vent & RWVent Rad Mon

DBA

Meteorology

EAL Enclosure 2

Vent Rad Monitor Detail (normal mode)

Enclosure 2

Vent Rad Monitor Detail (accident mode)

Enclosure 2

Affect of the Deficiencies

• Iodine concentration can be overestimated by a factor of ten

• However, concentration is not the only input to calculating dose

• The EDCP deficiencies affect the dose • Containment Spray operation > 30 minutes • Unit Vent is in accident mode with operable HEPA

• In these cases, the Iodine concentration is determined using an Iodine to Noble Gas ratio

• So, the result is dependent upon the Noble Gas concentration rather than the iodine concentration

Enclosure 2

Affect of the Deficiencies (cont.)

• The ten Design Basis Accidents in EDCP were reviewed to determine the significance of the deficiencies. o LOCA and Fuel Handling Accident o No credible scenarios for combining deficiencies

Containment Spray TEDE Factor CDE Factor

LOCA 1.5 1.5

Unit Vent Filtration TEDE Factor CDE Factor

Fuel Handling Acc. 1.0 1.1

LOCA 3.0 3.8 Enclosure 2

Summary

• EAL decision making was unaffected by these deficiencies o In order to have a dose assessment large enough to cause an

EAL declaration, plant conditions will drive declarations o EDCP calculations lag plant conditions

• PAR decision making was unaffected by these deficiencies o Initial PARs are plant condition based o Dose assessment is used for follow-up PARs or to prove initial

PARs • One of five EDCP calculation methods was affected with the

largest impact involving a LOCA

o Had this event actually occurred, a GE would have been declared based on plant conditions and a corresponding plant condition PAR evacuating 0-2 miles around and 10 miles downwind would be made

o The EDCP deficiencies would not have any impact because they would not have been used to develop these PARs Enclosure 2

Wolf Creek

Closing Remarks

Russell Smith - Site Vice President & CNOO

Enclosure 2

Acronym list

• EP – Emergency Planning

• EDCP – Emergency Dose Calculation Program

• HEPA – High Efficiency Particulate Air

• LOCA – Loss of Coolant Accident

• TEDE – Total Effective Dose Equivalent

• CDE – Committed Dose Equivalent

• EAL – Emergency Action Level

• PAR – Protective Action Recommendation

• GE – General Emergency

• CNOO – Chief Nuclear Operating Officer Enclosure 2