05000443/FIN-2011003-02
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Finding | |
|---|---|
| Title | lnadequate 50.59 Screening for Design Change EC 272057. |
| Description | NextEra issued EC272057, Concrete Modulus of Elasticity Evaluation, on April 24, 2011 to address the results of testing that showed a reduction in the concrete modulus of elasticity in the CEB (AR 1644074). EC272057 also address the reduced modulus in the Control Building/Electric Tunnel CB/ET (AR581434). The lowest measured modulus was 2.16E+03 ksifor the CEB and 2.1E+03 ksi for the CB/ET, both less than the design value of 3.62E+03 ksi. EC272057 was supported by calculations C-S-1-10150 and C-S-1-10156 which reflected the degraded conditions in the design calculations CD-20-CALC and CE-4-CALC for the control and containment enclosure buildings, respectively. NextEra concluded the structures remained operable and used EC272057 to disposition the degraded condition as use-as-is, by incorporating the degraded condition into the design basis. In a safety evaluation screen per 10 CFR 50.59 for EC272Q57, NextEra concluded the change to the facility did not require a complete evaluation per 50.59(cX2) because adequate design margin existed and there was no adverse affect on an UFSAR described design function. The inspectors determined the 50.59 Screen for EC272057 did not correctly address Screen Question 5.a: Does the proposed activity involve a change to an SSC that adversely affects an IJFSAR design function? Using the guidance of the Seabrook 1OCFR5059 Resource Manual and NEI 96-07, Revision 1, the inspectors determined that a 50.59 evaluation is specified for changes that adversely affect design function. ln this situation, the ASR impacted concrete with reduced modulus of elasticity which reduces the flexural capacity of the walls would be an adverse effect. Therefore, NextEra should have evaluated the change to the facility per 10 CFR 50.59(cX2). The item is unresolved pending action by NextEra to complete a full 50.59 evaluation for EC272057 and subsequent NRC review of that evaluation to determine whether the performance deficiency is more than minor. |
| Site: | Seabrook  |
|---|---|
| Report | IR 05000443/2011003 Section 1R15 |
| Date counted | Jun 30, 2011 (2011Q2) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | J Johnson T Burns T Moslak W Raymond A Burritt A Turilin J Deboera Shaikhg Thomas M Modes R Conte S Chaudhary W Raymond |
| INPO aspect | |
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Finding - Seabrook - IR 05000443/2011003 | |||||||||||||||||||||||||||||||||||||||||||
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Finding List (Seabrook) @ 2011Q2
Self-Identified List (Seabrook)
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