05000390/FIN-2009002-02
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Finding | |
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| Title | Acceptability of Plant Alterations Without NRC Submittal |
| Description | A URI was identified following NRC review of a licensee decision not to provide a submittal in association with temporary alteration TACF 1-07-0002-065, implemented in March 2007 on the Emergency Gas Treatment System (EGTS). The temporary alteration (TACF 1-07-0002-065) changed the system start logic such that both trains would operate in automatic upon receiving the start signal. In their review of the licensees 10CFR50.59 evaluation, the inspectors found that the licensee had made a determination that no license amendment was required, though the supporting paragraph indicated a license amendment was appropriate and was to be accomplished in association with the licensees corrective action program (CAP). Upon further review, the inspectors determined that, as part of a 2005 functional evaluation, a single-failure vulnerability was determined to exist. That same evaluation also recognized that the dose consequence for the system, described in the UFSAR, was based on single fan operation. Given the calculation of record assumptions that all fan flow would be exhausted and the fact that both system fans could achieve flow via that path, the licensee determined that there was an increased beta dose consequence over that described in the UFSAR to Main Control Room operators. NUREG 0800, Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants, limits beta dose in the control room to 30 rem. Nuclear Energy Institute (NEI) 96-07, Guidelines for 10 CFR 50.59, Section 4.3.3, states that the criterion for a more than minimal increase in consequence is greater than 10% of the margin to the limit. For this specific case, based on the UFSAR beta dose value of 6.803 rem, an increase of greater than 2.320 rem [(30 rem - 6.803 rem)*0.1] would indicate a more than minimal increase in the consequence. Using the licensee\'s re-evaluated beta dose value of 9.757 rem, the consequence difference was determined to be a 2.954 rem increase in beta dose for main control room operators, which exceeds the NEI 96-07 criterion for a more than minimal increase. The licensee\'s determination of the need for a license amendment was carried as an action item in PER 91670. Between 2005 and 2007 the licensee installed two temporary modifications to address the single-point failure vulnerability. The resulting configuration, at the time of inspection, did not resolve, nor compensate for the flow conditions which resulted in the licensees determination of the need for a submittal as of 2005. During the 2009 inspection, the inspectors found that no licensee amendment request had been submitted to the NRC to support changing the UFSAR while the calculations of record continued to indicate that one was warranted. This issue was unresolved pending additional NRC review to assess the adequacy of the licensees actions in response to the functional evaluation and the adequacy of 10 CFR 50.59 evaluations associated with the related temporary EGTS configuration modifications. This item is identified as URI 05000390/2009002-02: Acceptability of Plant Alterations Without NRC Submittal |
| Site: | Watts Bar  |
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| Report | IR 05000390/2009002 Section 1R17 |
| Date counted | Mar 31, 2009 (2009Q1) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.17 |
| Inspectors (proximate) | J Nadel M Pribish D Mas-Penaranda R Williams R Monk W Lewis H Gepford E Guthried Mas Penarandah Gepford J Hamman M Pribish P Higgins R Lewis R Monk T Fanelli |
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Finding - Watts Bar - IR 05000390/2009002 | |||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Watts Bar) @ 2009Q1
Self-Identified List (Watts Bar)
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