ML102710282
| ML102710282 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 09/27/2010 |
| From: | Office of Nuclear Reactor Regulation |
| To: | Arizona Public Service Co |
| Gibson, Lauren, NRR/DORL/LPL4, 415-1056 | |
| References | |
| TAC ME4586, TAC ME4587, TAC ME4588 | |
| Download: ML102710282 (1) | |
Text
DRAFT SUPPLEMENTAL INFORMATION REQUIRED The licensee is requesting A separate condition entry for each SG for Condition A for one ADV inoperable for seven day completion time. Standard Technical Specifications do not permit separate condition entry. Please justify this discrepancy.
The licensee is requesting 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> completion time for two ADVs inoperable on one SG for Condition B. STS Condition B does not allow two inoperable ADVs on one SG for more than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Please explain if and how a design basis event could be mitigated if an accident on the SG with the operable ADV results in no ADVs available for accident mitigation.
STS does not permit separate entry conditions on multiple SGs, and the LCO is written to address only one SG at a time; therefore, the only one SG is permitted to have two ADVs inoperable. In their amendment request, the licensee incorrectly makes the assumption that STS condition B allows two ADVs may be inoperable on two SGs for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and uses this logic on page 9 of their amendment to help justify their proposed 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> CT is more conservative than STS. Please justify.
The licensee proposes for condition C the following words No OPERABLE ADV lines on either generator. The licensee uses the word either instead of the word both, which can lead to possible misinterpretation. The word either is generally used as a substitute by the word or. The meaning of the TS as worded can be inferred to mean no operable ADVs on SG A, or no ADVs operable on SG B. However, inferring from the licensees description in the TS basis, the intent of this condition is detailing a situation where all 4 ADVs are inoperable, which describes a condition where there are no operable ADVs on SG A and no operable ADVs on SG B. In addition, TS are typically stated to define inoperability; therefore, a typical condition would define what is inoperable, e.g. two ADVs inoperable on each SG. Without referring to the TS basis, the meaning of this condition is ambiguous. Please justify the word choice.