ML14052A204
| ML14052A204 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 02/20/2014 |
| From: | Cortopassi L Omaha Public Power District |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LlC-14-0022 | |
| Download: ML14052A204 (10) | |
Text
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jjjjjjjj Omaha Public Power District 444 South 1£f' Street Mall Omaha, NE 68102-2247 LlC-14-0022 February 20,2014 u.s. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Fort Calhoun Station, Unit No.1 Renewed Facility Operating License No. DPR-40 NRC Docket No. 50-285
References:
- 1. Letter from OPPD (L. P. Cortopassi) to NRC (Document Control Desk), "Fort Calhoun Station Unit No.1, License Amendment Request 13-01, Revision to Technical Specification Sections 2.0.1 and 2.7 for Inoperable System, Subsystem or Component Due to Inoperable Power Source," dated February 18, 2013 (LlC 0001)
- 2. Email from NRC (L. Wilkins) to OPPD (8. R. Hansher) Request for Additional Information (RAI), dated August 22, 2013
SUBJECT:
Response to Request for Additional Information (RAI) for Fort Calhoun Station (FCS)
License Amendment Request (LAR) to Revise Technical Specification Sections 2.0.1 and 2.7 Attached is the Omaha Public Power District (OPPD) response to the Nuclear Regulatory Commission (NRC) request for additional information (RAI) (Reference 2) regarding the License Amendment Request (Reference 1) proposing to revise technical specifications for an inoperable system, subsystem, or component due to an inoperable power source.
There are no new regulatory commitments being made in this letter.
In accordance with 10 CFR 50.91, a copy of this letter, without the attachment, is being provided to the designated State of Nebraska official.
If you should have any questions regarding this submittal or require additional information, please contact Mr. Bill R. Hansher, Supervisor-Nuclear Licensing, at 402-533-6894.
Employment with Equal Opportunity
U. S. Nuclear Regulatory Commission LlC-14-0022 Page 2 a
I declare under penalty of perjury that the foregoing is true and correct. Executed on February 20, 2014 Louis P. Cortopassi Site Vice President and CNO LPC/brh
Attachment:
Response to Request for Additional Information c: M. L. Dapas, NRC Regional Administrator, Region IV J. W. Sebrosky, NRC Senior Project Manager J. C. Kirkland, NRC Senior Resident Inspector Director of Consumer Health Services, Department of Regulation and Licensure, Nebraska Health and Human Services, State of Nebraska
LlC-14-0022 Attachment Page 1 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION OMAHA PUBLIC POWER DISTRICT FORT CALHOUN STATION, UNIT 1 DOCKET NO. 50-285 RAI1 The proposed TS LCO 2.0.1(2) states:
"When the reactor coolant temperature is > 300°F and a system, subsystem, train, component, or device is determined to be inoperable solely because its emergency power source is inoperable, or solely because its normal power source is inoperable, it may be considered OPERABLE for the purpose of satisfying the requirements of its applicable Limiting Condition for Operation, provided: (1) its corresponding normal or emergency power source is OPERABLE; and (2) all of its redundant system(s),
subsystem(s), train(s), component(s), and device(s) are OPERABLE, or likewise satisfy the requirements of this specification."
- a. "Within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> from discovery of either diesel generator inoperability, declare the required feature(s) associated with the inoperable diesel generator inoperable, when its redundant required feature (including the steam driven auxiliary feedwater pump FW-10) is inoperable."
- b. "Within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> from discovery of either house service transformer inoperability, declare the required feature(s) associated with the inoperable house service transformer inoperable, when its redundant required feature (including the steam driven auxiliary feedwater pump FW-10) is inoperable."
The wording of the above proposed TS LCO 2.0.1(2) appears similar to NUREG-0212, Revision 2, LCO 3.0.5. However, the proposed TS wording does not include the 2-hour verification of (1) and (2) above is satisfied and it does not include the required action and completion times to place the unit in a MODE in which the applicable Limiting Condition for Operation does not apply as identified in the NUREG. Please explain this inconsistency with NUREG-0212 and explain why continued safe operation is assured without timely (within 2-hours) verification and actions consistent with those identified in NUREG-0212.
Response
The proposed change reflects the wording provided in NRC Generic Letter 80-30 (Reference 1) for Limiting Condition for Operation (LCO) 3.0.5 and was the basis for the wording of the Fort Calhoun Station (FCS) Technical Specifications (TS) prior to Amendment No. 264. The wording for LCO 3.0.5 in Generic Letter 80-30 did not include this additional action. As written, the guidance is consistent with all current NRC Improved Standard TS (NUREG-1430 through NUREG-1434) and FCS TS Amendment No. 264. The action is required upon discovery, not allowing a 2-hour period to verify status of components.
LI C-14-0022 Attachment Page 2 The proposed relocation of " a" and " b" from TS 2.7, Electrical Systems, to TS LCO 2.0.1 is inconsistent with NUREG-0212 and NUREG-1432. Please explain how these changes more align Ft Calhoun TS with NUREG-0212 Revision 2, " Standard Technical Specifications [STS] for Combustion Engineering Plants," as stated in the application.
Response
The TS changes to re-Iocate "a" and "b" from TS 2.7 are comparable to the STS contained in NUREG-1432 and would :
- 1. Remove the mandatory unit shutdown requirement should an emergency diesel generator or house service transformer be inoperable while a required feature(s) on the opposite train is inoperable. Instead, any TS required actions are based on the inoperability of the required feature(s) on the opposite train .
- 2. Basing the required actions on the inoperability of the required feature(s) ensures that the TS do not contain conflicting actions. For example, TS 2.15(3) states that operation can continue without containment ventilation isolation signals available if the ventilation isolation valves are closed. Radiation monitors supplying this signal are located on a 480V skid and are therefore powered from the Station's 480V system. Plant operation can continue if the radiation monitors that provide the signals are physically inoperable provided the allowable bypass conditions of TS 2.15 are met. However, if one radiation monitor is physically inoperable and another monitor is inoperable due to its emergency diesel generator being inoperable, NUREG-0212 guidance would result in an immediate unit shutdown. The correction of these inconsistencies was one of the reasons that OPPD submitted the LAR resulting in Amendment No. 264.
- 3. Include the steam driven auxiliary feedwater (AFW) pump operability requirements to the required redundant feature actions to be comparable with the Bases of NUREG-1432.
As stated in the safety evaluation report (SER) for Amendment No. 264:
"Current TS LCO 2.0.1(2) provides guidance on actions to be taken when either a normal or emergency power supply is inoperable. The licensee proposes to delete this paragraph and relocate guidance for inoperable power supplies (Le. transformer or DG) and verifying operability of redundant components to TS LCO 2.7, "Electrical Systems," to be more consistent with STS. TS LCO 2.7 provides the conditions of electrical power availability for safe reactor operation. Currently, if a house service transformer (T1A-3 or T1A-4) or a DG is inoperable, both TS LCO 2.0.1(2) and TS LCO 2.7 are applicable but together create several inconsistencies. As an example, the licensee stated that TS LCO 2.7(2)b allows one transformer to be inoperable and does not require a review of components associated with the other transformer. In addition, TS LCO 2.7(2)j allows one DG to be inoperable if the required engineered safeguards components associated with the other DG are operable and does not account for verification of the steam-driven AFW pump, a safeguards component. TS LCO 2.5, "Steam and Feedwater Systems," defines the conditions when the AFW system is required to be operable. Thus, to remove these inconsistencies, the licensee is proposing to delete TS
LlC-14-0022 Attachment Page 3 LCO 2.0.1(2) and revise the guidance in TS LCO 2.7 to require equivalent operability checks of redundant features."
"The licensee is proposing to delete TS LCO 2.0.1 (2) to remove the unit shutdown requirement if a DG or house service transformer is inoperable while a required feature on the opposite train is inoperable. The guidance is being moved to TS LCO 2.7(2)b and TS LCO 2.7(2)j. The required actions will be based on the inoperability of the required feature. The licensee is proposing to retain the guidance of TS LCO 2.0.1 (2) to declare the required systems and components inoperable when (1) either the normal or emergency power source is inoperable and (2) a redundant system or component is also inoperable. Based on the above, the NRC staff concludes this change acceptable since the guidance of TS LCO 2.0.1 (2) is being relocated to eliminate inconsistencies. The NRC has no objection to the conforming changes being made to the TS LCO 2.0.1 Basis."
The proposed relocation of "a" and "b" from TS 2.7, Electrical Systems, to TS LCO 2.0.1would relocate this NRC accepted change to address the inconsistencies addressed by the issuance of Amendment No. 264, while revising the definition of operable back to the wording that existed in the TS prior to Amendment No. 264.
RAI3 TS 2.0 Limiting Conditions for Operation, 2.0.1 General Requirements, Applicability states:
"Applies to the operable status of all systems, subsystems, trains, components, or devices covered by the Limiting Conditions for Operation."
Please identify all affected LCOs and the provide the reason(s) and safety justification for the proposed TS LCO 2.0.1 (2) relaxation of the electrical power LCO Operability requirements for a system, subsystem, train, component or device when reactor coolant (RC) temperature is greater than 300 degrees F as compared to when the RC temperature is less than 300 degrees F (e.g., LCO 2.2, Chemical and Volume Control System Charging Pumps, Boric Acid Pumps, etc.)
Response
In 1980 (Reference 1), the NRC mandated that all plants incorporate additional operability guidance in their TS for situations when a normal or emergency power supply is inoperable and provided the model TS to be included. OPPD implemented this guidance by including a definition of operable/operability and guidance in TS 2.0.1 (2) via TS Amendment No. 52 (Reference 2).
TS LCO Applicability for the major components required for design basis accidents or transients are shown below.
TS LCO 2.1 Reactor Coolant System TS 2.1.1 - contains requirements for decay heat removal loops with reactor coolant system temperatures below 300°F and reactor vessel head tensioned. As stated in the LAR, FCS is not
LI C-14-0022 Attachment Page 4 designed or licensed to General Design Criterion 34 on loss of residual heat removal; therefore, emergency power is not required for TS operability of these components. Electrical power supplies for shutdown cooling operations are controlled by plant procedures in accordance with regulatory commitments made in response to NRC Generic Letter 88-17, but are not required to meet the TS definition of operable.
In 1980 (Reference 4), the NRC requested that all PWRs amend their TS with respect to decay heat removal capability. The request was to provide assurance that redundancy in decay heat removal capability would be maintained and stated: To assist you in preparing your submittal, we have enclosed a copy of Model TSs which would provide an acceptable resolution of our concern. This document did not request/require additional TS for emergency power supplies during operation of the decay heat removal equipment and did not revise the FCS licensing basis to require compliance to GDC 34. Technical Specifications for the decay heat removal loops were added in Amendment 56 (Reference 3) with the NRC stating: Since your application, as modified with concurrence of your organization, resolves the staff's concerns and is in accordance with the staff's guidance, we find your application to be acceptable.
TS LCO 2.2 Chemical and Volume Control Systems TS 2.2.1 and TS 2.2.3 - contains requirement for charging/high pressure safety injection (HPSI) pumps and boric acid flow path in operating modes 4 and 5 when fuel is in the reactor, if no flow path is operable core alterations are suspended.
TS 2.2.2 and TS 2.2.4 - contains requirement for charging pumps when reactor coolant temperature is above 210°F.
As stated in USAR Section 9.2.3.7, no credit is taken for charging pump operation in the USAR Section 14 safety analyses; therefore, emergency power is not required for TS operability of these components.
TS LCO 2.3 Emergency Core Cooling System This LCO is applicable in operating modes 1 and 2 only.
TS LCO 2.4 Containment Cooling This LCO is applicable in operating modes 1 and 2 only and contains requirements for containment cooling and filtering, containment spray, component cooling and raw water systems.
TS LCO 2.8 Refueling Shutdown Contains requirements for decay heat removal loops with reactor coolant system temperatures below 300°F and reactor vessel head is not fully tensioned. As stated for LCO 2.1.1, FCS is not licensed or designed to General Design Criterion 34; therefore, emergency power is not required for TS operability of these components.
LlC-14-0022 Attachment Page 5 In the LAR dated February 18, 2013, the licensee provided proposed changes to the TS 2.7 minimum requirements for the Limiting Condition of Operation (LCO) for Electrical Systems for the condition when reactor coolant temperature will be > 300 0 F (applicable to the availability of electrical systems for the operation of plant components). However, the staff did not find the minimum requirements for the LCOs and Surveillance Requirements (SRs) for electrical systems when reactor coolant temperature will be <
300 0 F. NUREG-0212 also contains minimum requirements for LCOs during shutdown condition for electrical equipment in TS 3.8.1.2, 3.8.2.2, 3.8.2.4 and related surveillance requirements (SRs) in TS 4.8.1.2, 4.8.2.2, 4.8.2.4.1 and 4.8.2.4.2. Please provide justification for deviation from NUREG-0212 for not including above LCOs and SRs for shutdown conditions when reactor coolant temperature < 300 0 F. Please provide an overview of all electrical equipment required to be operable for reactor coolant temperature < 300 0 F.
Response
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As stated in the LAR, FCS Unit 1 was not designed or licensed to General Design Criterion 34 on loss of residual heat removal. The TS applicability for electrical power supplies is as the original TS were, applying when the RCS temperature is above 300°F. Below 300°F is the temperature to transition to shutdown cooling.
In 1980 (Reference 1), the NRC mandated that all plants incorporate additional operability guidance in their TS for situations when a normal or emergency power supply is inoperable and provided the model TS to be included. As stated in the Generic Letter, The NRC's Standard Technical Specifications (STS) were formulated to preserve the single failure criterion for systems that are relied upon in the safety analysis report. The Generic Letter requested that, Therefore, we request that you (1) submit proposed changes to your technical specifications within 30 days, that incorporate the requirements of the enclosed Model Technical Specifications, and (2) implement the above described procedures to assure compliance with your proposed changes within 30 days thereafter.
The model TS included in the Generic Letter did not include the additional TS for electrical components in lower operating modes. OPPD implemented this guidance by including a definition of operable/operability and guidance in TS 2.0.1 (2) via Amendment No. 52 (Reference 2). As stated in the Safety Evaluation Report (SER) for Amendment 52, The proposed specifications differ from the guidance provided in the allowable time for placing the reactor in hot shutdown condition (subcritical at operating temperature and pressure). The SER concluded that: Since this proposal was submitted in response to the staff's request and is in conformance with that request, except for the agreed to deviation noted above, we find the proposed additional requirements to be acceptable.
In 1980 (Reference 4), the NRC also required all pressurized water reactors (PWR) to amend their TS with respect to decay heat removal capability. The request was to provide assurance that redundancy in decay heat removal capability would be maintained. This document did not request/require additional TS for emergency power supplies during operation of the decay heat removal equipment and did not revise the FCS licensing basis to require compliance to GDC 34.
LlC-14-0022 Attachment Page 6 Loss of residual heat removal was addressed in NRC Unresolved Safety Issue A-45 and was closed for FCS Unit 1 in the safety evaluation for the Individual Plant Examination (IPE)
(Reference 5).
Based on the licensee's IPE process used to search for decay heat removal (DHR) vulnerabilities, and review of the Fort Calhoun plant-specific features, the staff finds the licensee's DHR evaluation consistent with the intent of the USI A-45 (DHR Reliability) resolution and is, therefore acceptable.
Generic Letter 88-17 (Reference 6) was issued with the following guidance for the addition of TS to support loss of residual heat removal:
(5) Technical Specifications Technical specifications (TSs) that restrict or limit the safety benefit of the actions identified in this letter should be identified and appropriate changes should be submitted.
The generic letter provided the following background discussion for the addition of TS:
3.5.2 Discussion Typical potential impacts include TSs that control containment; DHR system flow rate; the autoclosure interlock; equipment operability, operation, and availability; and instrumentation.
One objective we wish to achieve is a simplification of TSs as nonpower operation is investigated. Consequently, we will consider alternatives to placing requirements in TSs when such alternatives achieve the same purpose. For example, procedures requiring certain DHR equipment to be available before an operation is initiated may be sufficient, and such specifications then would not appear in TSs.
No additional TS were identified as necessary, and the NRC inspected and concurred with that conclusion in NRC Inspection Report 92-16 (Reference 7).
Improved Standard TS identify LCOs for electrical components in lower operating modes as meeting Criterion 3 of 10 CFR 50.36(c)(3) as a structure, system, or component which functions or actuates to mitigate a design basis accident or transient. As discussed previously, operation of emergency power supplies in lower operating modes were not part of an FCS design basis accident. The operation of emergency power supplies in lower operating modes is administratively controlled by NRC commitments in response to documents such as Generic Letter 88-17 and are not subject to TS operability requirements when the reactor coolant temperature is less than 300°F.
The proposed TS LCO 2.0.1, Specification (2) in the LAR dated February 18, 2013, states, in part "its corresponding normal or emergency power sources is OPERABLE". This statement does not appear to be consistent with the proposed change in definition of "Operable - Operability" which reflects "normal and emergency electrical power sources.
LlC-14-0022 Attachment Page 7
- 1) Please explain the discrepancy between the proposed changes.
- 2) License Amendment No. 264 approved changes to definitions of "Operable-Operability and as a consequence, inadvertently changed the requirement for an operable emergency power source, when reactor coolant temperature is < 3000 F.
Please provide details on operability requirements of equipment that will be impacted if the proposed change to TS LCO 2.0.1, Specification (2) in the LAR with the requirement for normal or emergency power is approved.
Response
- 1) The proposed TS LCO 2.0.1(2) reflects guidance provided in NRC Generic Letter 80-30 (Reference 1) that provides an exception to the definition of Operable. The proposed TS LCO 2.0.1 (2) allows a component to be considered operable if either normal or emergency power is operable, and the redundant component is operable.
- 2. The definition of operable is being revised back to as it was prior to Amendment No.
264, requiring both normal and emergency power to be operable to support systems, subsystems, and components. Therefore, whenever a diesel generator or power source is inoperable, all the components powered from those sources would not meet the definition of operability. The proposed TS LCO 2.0.1 (2) is an exception and would allow the component(s) that do not have their normal or emergency power source to be considered operable, provided the redundant component(s) on the opposite train are operable. During this time, the limiting condition for operation for the power source would apply and limit the amount of time in this condition. Revising the definition to require both normal and emergency power sources to be operable without the proposed TS LCO 2.0.1 (2) would not allow a diesel generator to be taken out of service for required testing or maintenance without declaring all components powered by that diesel generator to be inoperable. in Enclosure (TS Pages Retyped ("Clean") Definitions 'Operable -
Operability") of the LAR dated February 18, 2013, states, "Implicit in this definition shall be the assumption that all necessary .... " does not appear to be consistent with NUREG-0212 Definition of "Operable - Operability." The NUREG-0212 Definition of "Operable -
Operability" does not include the underlined words as stated above. Please explain the reasons for adding additional words "Implicit in this definition shall be the assumption that" to the NUREG 02012 Definition of "Operable - Operability" in the proposed TS change."
Response
The proposed wording is that which existed prior to Amendment No. 264. The wording is based upon the Standard TS definitions provided in NRC Generic Letter 80-30 as approved in Amendment No. 52.
LlC-14-0022 Attachment Page 8 References :
- 1. NRC Generic Letter 80-30, "Clarification of the Term "Operable" as It Applies to Single Failure Criterion for Safety Systems Required by TS," dated April 10, 1980
- 2. Letter from NRC (R. A. Clark) to OPPD (W. C. Jones), "Amendment 52," dated October 14, 1980
- 3. Letter from NRC (R. A. Clark) to OPPD (W. C. Jones), "Amendment 56," dated February 10, 1981
- 4. Letter from NRC (D. G. Eisenhut) to All Operating Pressurized Water Reactors (PWRs),
"Request to Amend Technical Specifications with Respect to Decay Heat Removal Capability," dated June 11 , 1980 (NRC-80-0111)
- 5. Letter from NRC (L. R. Wharton) to OPPD (T. L. Patterson), "Fort Calhoun Station, Unit No.
1 - Review of Individual Plant Examination (IPE) Submittal - Internal Events (TAC No.
M74412)," dated December 9,1996 (NRC-96-0216)
- 6. NRC Generic Letter 88-17, "Loss of Decay Heat Removal," dated October 17, 1988
- 7. Letter from NRC (A. B. Beach) to OPPD (W. G. Gates), "NRC Inspection Report 50-285/92-16," dated September 19,1992 (NRC-92-0367)