05000341/FIN-2007003-06
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Finding | |
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| Title | INADEQUATE DETERMINATION OF MAXIMUM ALLOWABLE TEMPERATURE FOR HPCI PUMP OPERATION ( Section 1R21.3.b.6) |
| Description | The inspectors identified an unresolved item concerning the licensees operational restrictions for the HPCI pump. The HPCI pump specification identified a maximum design temperature for operation of HPCI pump as 140F. However, the licensees emergency operating procedure (EOP) allow operation of HPCI and reactor core isolation cooling (RCIC) pumps above 140F without providing an adequate description of the consequences of this operation. At the end of the inspection, the licensee did not resolve this concern. The inspectors needed this information to complete the assessment of this issue. Description: The HPCI pump data sheet 21A9243AR specified a maximum design fluid temperature of 140F. However, Note 3 of 6M721-5860, HPCI Process Diagram, specified that piping expansion calculations shall be performed at 170F. In addition, system specification 3071-504, HPCI System Design Specification, specified a design temperature of 170F for the pump discharge piping, minimum flow piping, and pump suction piping from the torus. The licensee confirmed that the HPCI piping was analyzed 16 Enclosure up to 170F. The inspectors review of EOP 29.100.01, Sheet 6 Curves, Cautions and Tables, indicated that HPCI operation is permitted at temperatures significantly greater than 140F and even 170F without any restrictions. The only exception was note two caution in procedure 29.100.01, Sheet 6, Operation of HPCI and RCIC turbines with suction temperatures above 140F may result in equipment damage. The inspectors identified the following concern with operation of HPCI pump above 140F. The HPCI pump and turbine lubrication oil and turbine governor fluid were self-cooled by HPCI process flow. Hence, high HPCI fluid temperatures could lead to loss of lubrication. The consequences of this loss could go beyond the loss of the HPCI pumping function. The loss of lubrication and turbine governor fluid for a multistage high-pressure pump could lead to a loss of pressure boundary due to the loss of pump and/or turbine seals, resulting in possible catastrophic failure of the pump and/or turbine cases, and even possible missile generation. Additionally should the HPCIs rotating equipment survive operation above 140F; operation above 170F (current analyzed temperature limit for HPCI piping) could further jeopardize the integrity of the HPCI piping including containment penetrations. The inspectors concluded that the caution note did not provide sufficient information to make an informed risk based decision since it did not address the potential pressure boundary failure. Based on the inspectors concerns, the licensee initiated CARD 07-24172 to review training on all EOP cautions and perform an engineering evaluation of operating beyond the limits imposed by EOPs cautions to determine if there were subsequent equipment failure limits that need to be either incorporated into EOPs or EOP training to provide the operators the necessary information to make emergency operating decisions. Based on fact that at the end of the inspection, the licensee did not complete the evaluation of this concern, the NRC concluded that additional review and evaluation were required following completion of the licensees corrective actions to assess whether or not the licensee has established adequate limits for operation of HPCI pump. Therefore, this issue is considered an unresolved item (URI 05000341/2007003-06) pending completion of the licensees review to assess the limits of the HPCI pumps operation and subsequent NRC review. |
| Site: | Fermi  |
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| Report | IR 05000341/2007003 Section 1R21 |
| Date counted | Sep 30, 2007 (2007Q3) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.21 |
| Inspectors (proximate) | A Dunlop M Munir B Palagi D Passehl M Shlyamberg F Baxter C Acosta Acevedoa Dunlopj Cassidy T Steadham M Phalen D Jones R Morris A Wilson V Meghani F Tran |
| INPO aspect | |
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Finding - Fermi - IR 05000341/2007003 | |||||||||||||||||||||||||
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Finding List (Fermi) @ 2007Q3
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