IR 05000261/2011012

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IR 05000261-11-012, 07/18/2011 Through 09/23/2011, H.B. Robinson Steam Electric Plant, Unit 2, URI Closure
ML112730346
Person / Time
Site: Robinson Duke Energy icon.png
Issue date: 09/30/2011
From: Nease R
NRC/RGN-II/DRS/EB2
To: Duncan R
Progress Energy Co
References
EA-11-230 IR-11-012
Download: ML112730346 (14)


Text

UNITED STATES ber 30, 2011

SUBJECT:

H. B. ROBINSON STEAM ELECTRIC PLANT - NRC INSPECTION REPORT 05000261/2011012 AND NOTICE OF ENFORCEMENT DISCRETION

Dear Mr. Duncan:

On September 23, 2011, the Nuclear Regulatory Commission (NRC) completed its follow up on 2 Unresolved Items (URIs) and 1 Licensee Event Report (LER) associated with your H.B. Robinson Steam Electric Plant Unit 2. The enclosed inspection report documents the inspection results, which were discussed on September 29, 2011, with members of your staff.

During this inspection, the NRC staff performed in-office reviews and an onsite inspection of activities conducted under your license as they relate to public health and safety, to confirm compliance with the Commission's rules and regulations and with the conditions of your license.

Based on the results of this inspection, no findings were identified. However, one licensee identified a violation which was determined to be of very low safety significance (Green) is listed in this report. Because of the very low safety significance and because it was entered into your corrective action program, the NRC is treating this violation as a non-cited violation (NCV)

consistent with Section 2.3.2 of the NRCs Enforcement Policy. If you contest the NCV, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the United States Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington DC 20555-0001, with copies to the Regional Administrator, Region II; the Director, Office of Enforcement, United States Nuclear Regulatory Commission, Washington, DC 20555-0001; and the NRC Resident Inspector at the H. B. Robinson Steam Electric Plant, Unit 2.

The enclosed report also documents a noncompliance for which the NRC is exercising enforcement discretion in accordance with Section 9.1 of the NRC Enforcement Policy, Enforcement Discretion for Certain Fire Protection Issues (10 CFR 50.48). The noncompliance involved a failure to ensure that one train of systems necessary to achieve and maintain hot shutdown conditions was free of fire damage, as required by 10 CFR Part 50, Appendix R, Section III.G.3. The NRC is not taking enforcement action for the noncompliance because it meets the criteria of the NRCs Interim Enforcement Policy Regarding Enforcement Discretion for Certain Fire Protection Issues (10 CFR 50.48). In this case, the NRC concluded that (1) Carolina Power & Light entered the noncompliance into its corrective action program

Progress Energy 2 and implemented appropriate compensatory measures; (2) the noncompliance was not associated with a finding that the reactor oversight process significance determination process would evaluate as Red; (3) it was not willful; and (4) Carolina Power & Light submitted a letter of intent before December 31, 2005, stating its intent to transition to 10 CFR 50.48(c), which includes approaches in National Fire Protection Association Standard 805-2001 Edition (NFPA 805). Regarding compensatory measures, your staff has taken steps to direct operators to close PORV block valves and to verify that the A charging pump is not running upon confirmation of a fire in the affected fire zones. Additional corrective actions and plant modifications are planned to occur as part of your transition to NFPA 805. Based on the above corrective actions, and in accordance with NRC Inspection Manual Chapter 0305, Sections 11.05.b and 11.05.c, Violations in Specified Areas of Interest Qualifying for Enforcement Discretion, the NRC will also refrain from including the noncompliance in the Agency Action Matrix.

In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter, its enclosure(s), and your response (if any), will be made available electronically for public inspection in the NRC Public Document Room or from the NRC's document system (ADAMS),

accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).

Sincerely,

/RA by Frank J. Ehrhardt/

Rebecca L. Nease, Chief Engineering Branch 2 Division of Reactor Safety Docket No.: 50-261 License No.: DPR-23

Enclosure:

Inspection Report 05000261/2011012 w/Attachment: Supplemental Information

REGION II==

Docket Nos.: 50-261 License Nos.: DPR-23 Report No.: 05000261/2011012 Facility: H.B. Robinson Steam Electric Plant, Unit 2 Location: Hartsville, South Carolina Dates: July 18 - September 23, 2011 Inspectors: P. Braxton, Reactor Inspector J. Montgomery, Reactor Inspector R. Rodriguez, Senior Reactor Inspector Approved by: Rebecca L. Nease, Chief Engineering Branch 2 Division of Reactor Safety Enclosure

SUMMARY OF FINDINGS

IR 05000261/2011-012; 07/18/2011 through 09/23/2011; H.B. Robinson Steam Electric

Plant, Unit 2; URI Closure This report covers an in-office review and an onsite inspection of 2 unresolved items (URI) and 1 licensee event report (LER) by a team composed of three regional inspectors. No findings were identified. The significance of most findings is indicated by their color (Green, White, Yellow, Red) using Inspection Manual Chapter (IMC) 0609,

Significance Determination Process (SDP). The cross cutting aspects were determined using IMC 0310, Components within the Cross Cutting Areas. Findings for which the SDP does not apply may be Green or be assigned a severity level after NRC management review.

NRC-Identified and Self-Revealing Findings

None

Licensee Identified Violations

A violation of very low safety significance that was identified by the licensee has been reviewed by the inspectors. Corrective actions taken or planned by the licensee have been entered into the licensees corrective action program. This violation and corrective action tracking number are listed in Section 4OA7 of this report.

REPORT DETAILS

OTHER ACTIVITIES

4OA3 Follow-Up of Events and Notices of Enforcement Discretion

.01 (Closed) Licensee Event Report (LER) 05000261/2008-001-00: Appendix R Pathway

Impassable due to Lock Configuration

a. Inspection Scope

On January 21, 2008, the licensee discovered that a credited Appendix R safe shutdown pathway was not available due to an improperly locked gate. The details of this LER are discussed in NRC Inspection Report 05000261/2010007. The inspectors performed a detailed review of the information related to the LER. Inspectors reviewed documents, performed walkdowns, and discussed the event with plant personnel to gain an understanding of the event. The inspectors assessed the licensees corrective actions to determine if they were adequate.

b. Findings

Enforcement aspects of this LER are discussed in Section 4OA7 of this inspection report. This LER is closed.

4OA5 Other Activities

.01 (Closed) Unresolved Item (URI)05000261/2004006-03, Appendix R Safe Shutdown

Vulnerabilities.

a. Inspection Scope

The team reviewed the facts of the subject URI as well as evaluations and corrective actions taken by the licensee.

b. Findings

Introduction:

A noncompliance was identified for the failure to protect control circuits that could cause maloperation of both pressurizer power-operated relief valves (PORVs) and associated block valves. This maloperation could result in the failure to maintain reactor coolant system (RCS) process variables within those predicted for a loss of normal alternating current (AC) power, as required by 10 CFR 50, Appendix R, Section III.L.

This noncompliance is applicable to fires in fire zones (FZ) 19 (Cable Spreading Room),

FZ 20 (Emergency Switchgear Room), and FZ 22 (Main Control Room). Additionally, cables for level control valves LCV-115C (charging pump suction from the VCT) and LCV-115B (charging pump suction from the RWST) were also found to be vulnerable to fires in the same fire zones.

Description:

As discussed in NRC inspection report 05000261/2004006, these vulnerabilities were identified by the licensee in LER 05000261/2003003. During the baseline triennial fire protection inspections in 2004 and 2010, the inspectors reviewed the facts of the subject LER, as well as evaluations and corrective actions taken by the licensee. A brief summary of the vulnerabilities is provided below:

  • Fires causing spurious opening of the pressurizer PORVs and damage to their associated block valves could cause a rapid drop in RCS pressure and the loss of an unrecoverable amount of RCS coolant in less than 10 minutes.
  • Fires causing spurious closure of LCV-115B and/or LCV-115C could cause a loss of suction and subsequent failure of the running charging pump. Loss of the A charging pump would represent a loss of the Dedicated Shutdown RCS makeup function.

As stated in the LER, the licensee took immediate compensatory measures, in that the operators were directed to close the PORV block valves and to verify that the A charging pump was not running upon confirmation of a fire in the affected FZs. The inspectors challenged the adequacy of these immediate compensatory measures and documented the concerns in URI 05000261/2004006-04. The results of the review of that URI are discussed in the next section of this report. Additional corrective actions and plant modifications are planned to occur as part of the licensees transition to National Fire Protection Association (NFPA) Standard 805 NFPA 805, Performance-Based Standard for Fire Protection for Light-Water Reactor Electric Generating Plants.

Analysis:

The failure to protect one train of cables and equipment necessary to achieve post-fire safe shutdown from fire damage, as required by 10 CFR Part 50, Appendix R, Section III.G.3, is a performance deficiency. The noncompliance is considered to be more than minor, because it is associated with the protection against external factors (i.e. fire) attribute and degraded the reactor safety Mitigating Systems cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent consequences. The team assessed the noncompliance using the Fire Protection Phase 1 Worksheet contained in NRC Inspection Manual Chapter 0609, Appendix F, Attachment 1, and concluded that a Phase 3 analysis was necessary because the noncompliance involved fires leading to main control room abandonment.

A regional senior reactor analyst performed a Phase 3 evaluation to determine if this noncompliance would be associated with a finding of high safety significance (Red). The analysis considered scenarios where a fire would damage cables for the PORV and its associated block valve. Scenarios involving the loss of a charging pump were not considered further, because the operators would have time to secure the pump (which could operate for a short time), before sustaining non-recoverable damage. Based upon the following facts, the Phase 3 analysis concluded that this item would not be associated with a finding of high safety significance (Red):

  • Multiple hot shorts would be necessary to spuriously open the pressurizer PORVs,
  • Additional fire damage would be necessary to damage the block valves, and
  • The fire zones are protected by an automatic Halon suppression system.

The inspectors found that this performance deficiency did not have a cross-cutting aspect, because it did not represent current licensee performance.

Enforcement:

10 CFR 50.48(b)(1) requires, in part, that all nuclear power plants licensed to operate prior to January 1, 1979, must satisfy the applicable requirements of Appendix R,Section III.G.Section III.G.3 invokesSection III.L, which requires that the alternate or dedicated post-fire SSD capability be able to achieve and maintain hot standby conditions and the RCS process variables shall be maintained within those predicted for a loss of normal alternating current power. Also, 10 CFR 50, Appendix R, and related NRC Fire Protection SERs dated August 8, 1984, and November 21, 1985, confirmed the licensees compliance with Sections III.G. and III.L.

Contrary to the above, prior to November 19, 2003, the licensees alternative/dedicated post-fire SSD capability for a fire in FZs 19, 20, or 22 did not meet these requirements.

Specifically, spurious opening of the pressurizer PORVs and damage to their associated block valves could cause a rapid drop in RCS pressure and the loss of an unrecoverable amount of RCS coolant in less than 10 minutes. Additionally, spurious operation of the charging pump suction valves could result in damage to the A charging pump, which in turn, could result in failure to maintain RCS makeup. These nonconforming conditions have existed since the requirements of Appendix R became applicable to HB Robinson in 1984.

Because the licensee committed to adopt NFPA 805 and change their fire protection licensing bases to comply with 10 CFR 50.48(c), and this commitment was documented prior to December 31, 2005, the NRC is exercising enforcement and reactor oversight process discretion for this issue in accordance with the NRC Enforcement Policy, Interim Enforcement Policy Regarding Enforcement Discretion for Certain Fire Protection Issues (10 CFR 50.48). Specifically, it was likely this issue would have been identified and addressed during the licensees transition to NFPA 805, it was entered into the licensees corrective action program, immediate corrective action and compensatory measures were taken, it was not likely to have been previously identified by routine licensee efforts, it was not willful, and it was not associated with a finding of high safety significance (Red).

The unresolved item is now closed.

.02 (Closed) URI 05000261/2004006-04, Inadequate Corrective Actions for Appendix R

Safe Shutdown Vulnerabilities.

a. Inspection Scope

The team reviewed the facts of the subject URI as well as evaluations and corrective actions taken by the licensee. As discussed in NRC inspection report number 05000261/2004006, the licensee conducted an adverse condition investigation, documented in Action Request 136517. This action request addressed the concern regarding inadequate corrective actions taken for the Appendix R safe shutdown vulnerabilities identified in Section 4OA5.01 of this inspection report. The licensee concluded that, given the combination of conservative assumptions applied, the mitigating factors not credited as a part of the corrective actions (some of which are credited in the current licensing basis of the plant), and the influential factors associated with the postulated fire-induced circuit failures, the initial compensatory measures provided adequate assurance that the core would remain covered during certain postulated fire events. In the case of the pressurizer PORVs, it was shown by calculation and simulation of plant response that the operator manual actions to remove power and close the valves can be achieved prior to core uncovery, with no resulting core damage. Furthermore, once the pressurizer PORVs are closed, de-energized, and the reopening of its associated block valve would have no additional adverse consequence. The inspectors reviewed the licensees conclusions and agree that the compensatory measures/corrective actions were adequate.

b. Findings

No findings were identified. This unresolved item is closed.

4OA6 Meetings, Including Exit

On September 29, 2001, regional inspectors discussed the results of this inspection with members of the licensees staff. The licensee acknowledged the findings. The licensee also confirmed that proprietary information was not provided or examined during the inspection.

4OA7 Licensee-Identified Violations

The following violation of very low safety significance (Green) was identified by the licensee and is a violation of NRC requirements, which meets the criteria of the NRC Enforcement Policy, for being dispositioned as a Non-Cited Violation.

Robinson Fire Protection License Condition 2.E states that Carolina Power & Company shall implement and maintain in effect all provisions of the approved Fire Protection Program as described in the Updated Final Safety Analysis Report for the facility and as approved in the Fire Protection Safety Evaluation Report dated February 28, 1978, and supplements thereto. The supplemental SER dated August 8, 1984, states that alternate shutdown, pursuant to paragraph III.G.3 of Appendix R to 10 CFR 50, is required for a fire in the emergency switchgear room. Paragraph III.G.3 requires, in part, that alternative shutdown capability be provided where the protection of systems whose function is required for hot shutdown does not satisfy the requirement of paragraph III.G.2. Contrary to this, on January 21, 2008, the licensee identified that a credited Appendix R safe shutdown pathway was not available to support safe shutdown, due to an improperly locked gate (see Section 4OA3 of this report). This issue was determined to be of very low safety significance (Green) based on the results of the IMC 0609, Appendix F, Fire Protection Significance Determination Process, Phase III Quantitative Screening Approach. This violation was documented in the licensees corrective action program as NCR 280422.

Although H.B. Robinson committed, prior to December 31, 2005, to adopt NFPA 805 and change their fire protection licensing basis to comply with 10 CFR 50.48(c), the NRC is not exercising enforcement discretion for this issue, because it does not meet all of the criteria of NRC Enforcement Policy, Interim Enforcement Policy Regarding Enforcement Discretion for Certain Fire Protection Issues (10 CFR 50.48). Specifically, the inspectors determined that it was not likely that the licensee would have identified this issue as part of its NFPA 805 transition activities.

ATTACHMENT:

SUPPLEMENTAL INFORMATION

KEY POINTS OF CONTACT

Licensee personnel

Ray Buzzard, Licensing

B. Gerwe, Fire Protection Manager
F. Modlin, Safe Shutdown Engineer

NRC personnel

J. Hickey, Senior Resident Inspector, H.B. Robinson Steam Electric Plant
R. Nease, Chief, Engineering Branch 2, Division of Reactor Safety, Region II
G. MacDonald, Senior Reactor Analyst, Division of Reactor Projects, Region II

LIST OF DOCUMENTS REVIEWED