IR 05000261/1986018
| ML14358A455 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 08/20/1986 |
| From: | Conlon T, Ruff A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML14175B409 | List: |
| References | |
| 50-261-86-18, IEB-85-009, IEB-85-9, NUDOCS 8609080105 | |
| Download: ML14358A455 (7) | |
Text
C;tpf REC;&.1 UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, ATLANTA, GEORGIA 30323 Report No.:
50-261/86-18 Licensee: Carolina Power and Light Company P. 0. Box 1551 Raleigh, NC 27602 Docket No.:
50-261 License No.:
DPR-23 Facility Name: H. B. Robinson Inspection Conducted:
July 14-18, 1986 Inspector:A Approved by
_______
T. E. Conlon, Se Chi f Date Signed Plant Systems Section Division of Reactor Safety
SUMMARY Scope:
This routine, special announced inspection was conducted in the areas of 10 CFR 50, Appendix R Associated Circuit Results:
No violations or deviations were identifie PDR ADOCK 05000261 G
REPORT DETAILS 1. Persons Contacted Licensee Employees
- R. E. Morgan, General Manager
- H. J. Young, Director Quality Assurance/Quality Control (QA/QC)
- D. B. Bates, NELD
- D. Sayre, Regulatory Compliance
- F. Lowery, Manager Operations J. Royal, NELD J. Hart, NELD Other licensee employees contacted included technicians, operators, mechanics, security office members and office personne NRC Resident Inspectors H. Krug
- Attended exit interview 2. Exit Interview The inspection scope and findings were summarized on July 18, 1986, with those persons indicated in paragraph 1 abov The inspector described the areas inspected and discussed in detail the inspection finding listed belo No dissenting comments were received from the license Inspector Followup Item (IFI)
50-261/86-18-01, Periodic Testing/
Surveillance of Appendix R Protective Devices Associated With Appendix R Coordination Study [Paragraph 5.(2)].
The licensee did not identify as proprietary any of the material provided to or reviewed by the inspector during this inspectio. Licensee Action on Previous Enforcement Matters This subject was not addressed in the inspectio. Unresolved Items Unresolved items were not identified during the inspectio. Associated Circuits a. General This inspection was a followup of the associated circuit portion of an inspection made in February 1985 covered by NRC report 85-0 At the time of the 1985 inspection, H.B. Robinson was not required to have its Fire Protection Plan analysis complete or in effect. Consequently, two Inspector Followup Items (IFIs) were identified in the associated circuits area as indicated below:
(1) 50-261/85-07-03, Review Completed Coordination Study for Associated Circuits Common Power Supply (2) 50-261/85-07-04, Review of Common Enclosure Concerns for Normal/Alternative Shutdown Circuits These items are closed as a result of this inspectio The associated circuits of concern are identified in Generic Letter (G/L) 81-12 of February 20, 1981 and a supplement to this letter issued in the spring of 198 Associated circuits of concern are those circuits that have physical separation less than that required by 10 CFR 50, Section III G of Appendix R and having one of the following:
(1) A common power source (common bus) with the shutdown equipment and the power source is not electrically protected from the circuit of concern by coordinated breakers, fuses, or similar devices; or (2) A connection to circuits of equipment who spurious operation (spurious signal) would adversely affect the shutdown capability; or (3) A common enclosure with the shutdown cables, and
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(Type 1) are not electrically protected by circuit breakers, fuses or similar devices, or
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(Type 2) will allow propagation of the fire into the enclosur H. B. Robinson's Associated Circuit Analysis is covered by their report 7107-P-200 b. Associated Circuits by Common Power Supply (Common Bus)
Circuits and cables associated by common power supply are simply nonsafe shutdown cables whose fire-induced failure will cause the loss of a power source (bus, distribution panel, or MCC) that is necessary to support safe shutdown. This problem could exist for power, control, or instrumentation circuit The problem of associated circuits of
concern by common power supply is resolved by ensuring adequate electrical coordination between the safe shutdown power source supply breaker and the component feeder breaker or fuse The electrical distribution system coordination study is detailed by the licensee's task plan 7107-P-40 This report was reviewed and a sample selection of circuits were checked. The following are examples of the Time Current Curves (TCC)
that were reviewed during this inspectio TCC Number Description HBRAR.01-01 480V AC Bus 1 HBRAR.01-3 208V AC MCC #10 HBRAR.01-4 120V AC Inst. Bus 1 & 6 HBRAR.01-2 480V AC Bus El & MCC 5/5A HBRAR.01-5 120V AC Inst. Bus 2 & 7 HBRAR.01-6 125V DC MCC A HBRAR.0 V AC Inst. Bus 4 & 9 HBRAR.06-1 480V AC Bus 2 B HBRAR.04-1 480V AC Bus E2 & MCC 6/6A HBRAR.05-2 Dedicated Shutdown Dist Sy The licensee was asked about a periodic Testing/Surveillance program for Appendix R protective devices associated with the above coordination stud CP&L's representative indicated that most, if not all, protective device were covered by their periodic Test/Surveillance program, Technical Specification or other NRC requiremen There was no specific program for these devices and no list was available to indicate that all devices were addresse This item is identified as Inspector Followup Item 50-261/86-18-01, Periodic Testing/Surveillance of Appendix R Protective Devices associated with Appendix R Coordination Stud IE Information Notice 85-09, Isolation Transfer Switches and Post-Fire Shutdown Capability, was issued January 31, 198 This Notice identifies a potential problem concerning fuses in control circuits that are common for operation of equipment from the Control Room and Alternate Shutdown System A fire in the Control Room could cause these common fuses to blow before transfer is made to the Alternate Shutdown Syste If the control circuit is needed at the Alternate Shutdown System to energize a piece of equipment and if the fuse(s)
blew before transfer, equipment would not be operable without replacing the blown fuse(s). The licensee indicated that the transfer scheme for their Dedicated/Alternate Shutdown system was reviewed as a result of this information notice and for all cases in which a common power source is used both in the normal and alternate shutdown modes (i.e.,
control transfer only) redundant fuses are provide Several electrical schematics listed below were reviewed for redundant fuses and were found to be acceptable:
Drawing No B-190628 Description Sheet No. 201 Component Cooling Pump A Sheet No. 161 Charging Pump A Sheet No. 631A, B & C Steam Driven FWP Steam Shut - off Valve V1-8A Sheet No. 647A, B & C Steam Driven FWP Steam Shut - off Valve V2 -
14A c. Associated Circuits Causing Spurious Operation (Spurious Signals)
Circuits associated because of spurious operation are those that can, by fire-induced failures cause safe shutdown equipment of nonsafe shutdown equipment to maloperate in a way that affects the function of safe shutdown systems or equipment. Examples include the uncontrolled opening or closing of valves, or of circuit breakers, due to fire-induced damage to nonsafe shutdown instrument and control circuits that affect the control circuit of the safe shutdown component The licensee analysis of spurious operations was performed in conjunction with their Appendix R Separation Analysis 7107-P-300. This analysis considered equipment that could affect safe shutdown of the plan Redundancy between shutdown circuits with proper separation, protection, modification and/or analysis and the licensee's Alternate/Dedicated Shutdown System has been used to resolve this concer The high/low pressure interface electrically operated valves were reviewed in detail for spurious signal concern These valves are associated with the five systems listed below:
(1) The reactor coolant vent system (2) The letdown system (3) The primary sampling system (4) The power operated relief valve (PORV)/block valve (5) The RHR system (suction side valves)
The spurious operation of these valves were mitigated by valve redundancy, proper separation, protection of cables, analysis, operator actions and/or flow restrictors on small diameter piping or tubing installed in some reactor coolant system fluid line During this review it was noted that the valve position designation for some high/low pressure interface valves on sheet 1 of Reactor Coolant System Flow Diagram No. 5379-1971 Re was incorrect. The Licensee issued their FACTS #86R0159 to track and correct this discrepancy on a future revision of the pla d. Associated Circuits by Common Enclosure A circuit, whether safety-related or not, is classified as an associated circuit of concern if it shares a common enclosure (e.g.,
cable tray, conduit, panel or junction box) with a "Required Circuit,"
and is not adequately protected by circuit breakers, fuses or similar devices, or could allow fire propagation into the Shared Common Enclosur At H. B. Robinson, the definition of enclosure has been extended to include the entire fire are The propagation of fire through or between enclosure will be mitigated for the following reasons:
(1) Alternative/dedicated safe-shutdown circuits (Alternate A) are routed only in dedicated conduit and share no cabinets, raceways, or boxes with normal safe-shutdown circuits (Alternate B)
(2) All Alternate A cables are IEEE 383 qualified (3) Alternate B cables in cable trays in high density cable routing areas of the Auxiliary have been coated with a flame-retardant mastic to the extent practicable within the constraints imposed by construction and maintenance practice (4) Cable sizing and overcurrent protection are provided for safe-shutdown cable (5) Fire stops are installed whenever a cable penetrates a fire area e. Damage Control Measures An audit was performed on the material and equipment listed in the following Dedicated Shutdown Procedures (DSP):
(1) DSP-007, RHR Pump Power Repair Procedure (2) DSP-008, RHR System Flow Indicator Repair Procedure (3) DSP-009, SG PORV's Control Repair Procedure (4) DSP-010, RHR System Temp Indications Repair Procedure (5) DSP-011, Press PORV Control/Power Repair Procedure (6) DSP-012, RHR Flow Control Valves Repair Procedures The material/equipment for the above procedures was dedicated and located, as indicated in the procedures, in H. B. Robinson central warehouse. Except for RHR power cable, all equipment for the above DSP's was located in one storage box. The equipment was not identified by label or tagging, nor was it separated for a specific DS It also appeared that there was equipment in this box for DSP's that had been superseded by the licensee new DSP' The licensee stated that
equipment would be labeled for specific DSP's and that equipment not needed as a result of the issuance of their new DSP would be remove This is being tracked to insure items are labelled or separated by DSP by the licensee's FACTS #86R012.