Technical Specification 3.7.1.5 requires, in part, that each
main steam isolation valve be
operable in Modes 1, 2, and 3. If one
main steam isolation valve is
inoperable but open, power operation may continue provided that operability is restored within
4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. Contrary to the above, on September 17, 2009, the licensee identified that a wooden deck platform was built around
main steam isolation valve 1D that would have prevented the valve from fully closing. The violation was processed through the power operations
significance determination process and warranted a Phase 2 analysis because it resulted in the loss of safety function of one train of
main steam isolation valves for greater than the technical specification allowed outage time. The Phase 2 analysis determined that the violation had very low safety significance because the exposure time was less than 3 days. This finding is documented in the licensees corrective action program as Condition Report 09-14248.
