ML20198D538

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Proposed Tech Specs Page 142,correcting Wording to Reflect Previously Approved Wording,Last Revised in Amend 160
ML20198D538
Person / Time
Site: Vermont Yankee Entergy icon.png
Issue date: 12/15/1998
From:
VERMONT YANKEE NUCLEAR POWER CORP.
To:
Shared Package
ML20198D536 List:
References
NUDOCS 9812230111
Download: ML20198D538 (2)
v • d • e


Text

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VYNPS BAS E'S : 3.'6 and 4.6 (Cont'd) .G.BJ.b impurities will also be within their ormal ranges. The reactor cooling samples will also be used t determine the chlorides.

Therefore, the sampling frequency considered adequate to detect long-term changes in the chloride ion content. Isotopic analyses required by Specification (i.$.D.4)may be performed by a gamma scan and gross beta and alpha determination.

The conductivity of the feedwater is continuously monitored and alarm set points consistent with Regulatory requirements given in Regulatory Guide 1.56, " Maintenance of Water Purity in Boiling Water Reactors,"

have been determined. The results from the conductivity monitors on the feedwater can be correlated with the results from the conductivity monitors on the reactor coolant water to indicate demineralizer breakthrough and subsequent conductivity levels in the reactor vessel water. ,

C. Coolant Leakage i .

The 5 gpm limit Ior unidentified leaks w s established assuming such leakage was coming from the reactor coo ant system. Tests have been conducted which demonstrate that a rel tionship exists between the size of a crack and the probability that t e crack will propagate. These tests suggest that for leakage somew at greater than the limit specified for unidentified leakage the probability is small that imperfections or cracks associated with such leakage would grow rapidly. Leakage less than the limit specified can be detected within a few hours utilizing the available leakage detection systems. If the limit is exceeded and the origin cannot be determined in a reasonably short time the plant should be shutdown to allow further investigation and corrective action.

The 2 gpm increase limit in any 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period for unidentified leaks was established as an additional requirement to the 5 gpm limit by Generic Letter 88-01, "NRC Position on Intergranular Stress Corrosion Cracking (IGSCC) in BWR Austenitic Stainless Steel Piping."

The removal capacity from the drywell floor drain sump and the equivalent drain sump is 50 gpm each. Removal of 50 gpm from either of these sumps can be accomplished with considerable margin.

D. Safety and Relief Valves Safety analyses have shown that only three of the four relief valves hgp, are required to provide the recommended pressure margin of 25 psi below Ng! the safety valve actuation settings as well as compliance with the MCPR VMMR safety limit for the limiting anticipated overpressure transient. For

$OU* the purposes of this limiting condition, a relief valve that is unable

    • O to actuate within tolerance of its set pressure is considered to be as

$$ inoperable as a mechanically malfunctioning valve.

( [d The setpoint tolerance value for as-left or refurbished valves is specified in Section III of the ASME Boiler and Pressure Vessel Code as weg

@4 11% of set pressure. However, the code allows a larger tolerance value for the as-found condition if the supporting design analyses jg demonstrate that the applicable acceptance criteria are met. Safety

,, g uso analysis has been performed which shows that with all safety and safety P 4 Q- relief valves within 13% of the specified set pressures in Table 2.2.1 and with one inoperable safety relief valve, the reactor coolant pressure safety limit of 1375 psig and the MCPR safety limit are not exceeded during the limiting overpressure transient.

Chang: 1C/Merch 29, 19'd, la, 48, 448, 14G, 440,160 142

- . - . . . - - - - c.-. - . - . - - - - _ . - . . - . . - . - - .- - -. - . ~ . _ ..

  • .O' VYNPS BASES: 3.6 and 4.6 (Cont'd) impurities will also be within their normal ranges. The reactor cooling samples will also be used to determine the chlorides.

Therefore, the sampling frequency is considered adequate to detect long-term changes in the chloride ion content. Isotopic analyses l required by Specification 4.6.B.l.b may be performed by a gamma scan and gross beta and alpha determination.

The conductivity of the feedwater is continuously monitored and alarm set points consistent with Regulatory requirements given in Regulatory Guide 1.56, " Maintenance of Water Purity in Boiling Water Reactors,"

.have been determined. The results from the conductivity monitors on the feedwater can be correlated with the results from the conductivity monitors on the reactor coolant water to indicate demineralizer breakthrough and subsequent conductivity levels in the reactor vessel water.

C. Coolant Leakage The 5 gpm limit for unidentified leaks as established assuming such leakage was coming from the reactor coolant system. Tests have been conducted which demonstrate that a relationship exists between the size of a crack and the probability that the crack will propagate. These tests suggest that for leakage somewhat greater than the limit specified for unidentified leakage, the probability is small that l imperfections or cracks associated with such leakage would grow rapidly. Leakage less than the limit specified can be detected within a few hours utilizing the available leakage detection systems. If the limit is exceeded and the origin cannot be determined in a reasonably short time the plant should be shutdown to allow further investigation l and' corrective action.

The 2 gpm increase limit in any 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period for unidentified leaks was established as an additional requirement to the 5 gpm limit by Generic Letter 88-01, "NRC Position on Intergranular Stress Corrosion Cracking (IGSCC) in BWR Austenitic Stainless Steel Piping."

The removal capacity from the drywell floor drain sump and the equivalent drain sump is 50 gpm each. Removal of 50 gpm from either of these sumps can be accomplished with considerable margin.

D. Safety and Relief Valves Safety analyses have shown that only three of the four relief valves are required to provide the recommended pressure margin of 25 psi below the safety valve actuation settings as well as compliance with the MCPR safety limit for the limiting anticipated overpressure transient. For the purposes of this limiting condition, a relief valve that is unable to actuate within tolerance of its set pressure is considered to be as inoperable as a mechanically malfunctioning valve.

The setpoint tolerance value for as-left or refurbished valves is

. specified in Section III of the ASME Boiler and Pressure Vessel Code as

! 11% of set pressure. However, the code allows a larger tolerance value

! for the as-found condition if the supporting design analyses

, demonstrate that the applicable acceptance criteria are met. Safety analysis has been performed which shows that with all safety and safety

relief valves within 13% of the specified set pressures in Table 2.2.1 4'

and with one inoperable safety relief valve, the reactor coolant i" pressure safety limit of 1375 psig and the MCPR safety limit are not exceeded during the limiting overpressure transient.

I Chang 16/"crch 29, 1971, M, M, MB, M9, MG,MG 142 i .

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