ML20115B009
| ML20115B009 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 07/03/1996 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20115B011 | List: |
| References | |
| NUDOCS 9607090190 | |
| Download: ML20115B009 (2) | |
Text
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4 CONTAINMENT SYSTEMS BASES DEPRESSURIZATION SYSTEMS (Continued) i Because of the large volume and thermal capacity of the suppression pool, the vo'lume and temperature normally changes very alowly and monitoring these parameters daily is sufficient to establish any temperature trends.
By i
requiring the suppression pool temperature to be frequently recorded during periods of significant heat addition, the temperature trends will be closely followed so that appropriate action can be taken. The requirement for an external visual examination following any event where potentially high loadings could occur provides assurance that no significant damage was encountered.
i In addition'to the limits on temperature of the suppression chamber pool water, operating procedures define the action to be taken in the event of safety-relief valve inadvertently opens or sticks open. As a minimum this action shall include: (1) use of all available means to close the valve, (2) initiate suppression pool water cooling, (3) initiate reactor shutdown when l
suppression pool average water temperature is 110 F* or greater, and (4) if other safety-relief valves are used to depressurize the reactor, their l
discharge shall be separated from that of the stuck-open safety relief valve to assure mixing and uniformity of energy insertion to the pool, r
3/4.6.3 PRIMARY CONTAINMENT ISOLATION VALVES Primary Containment Isolation Valves (PCIVs) form a part of the primary containment boundary. The PCIV safety function is related to control of primary containment leakage rates during accidents or other conditions to limit the untreated release of radioactive materials from the containment in excess of the design limits.
The automatic isolation valves are required to have isolation times l
within limits and actuate on an automatic isolation signal. The valves covered by this specification are listed with their associated stroke times, and other design information for lines penetrating the Primary Containment, in UFSAR Section 6.2.
t The normally closed isolation valves are considered OPERABLE when manual valves are closed, automatic valves are de-activated and secured in their closed position, blind flanges are in place, and closed systems are intact.
Main steamlines through the isolation valves and hydrostatically tested valves must meet alternative leakage rate requirements. Other PCIV leakage rates are addressed by specification 3/4.6.1.1, " PRIMARY CONTAINMENT INTEGRITY". UFSAR Section 6.2 also describes special leakage test requirements and exemptions.
This specification provides assurance that the PCIVs will perform their designed safety functions to control leakage from the primary containment during accidents.
The opening of locked or sealed closed containment isolation valves on an intermittent basis under administrative control includes the following 4
considerations: (1) stationing an operator, who is in constant communication LA SALLE - UNIT I B 3/4 6-4 Amendment No.113 9607090190 960703 i
PDR ADOCK 05000373 i
P PDR
-l 4
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CONTAINMENT SYSTEMS
!,4i BASES i
j DEPRESSURIZATION SYSTEMS (Continued) j i
l Because of the large volume and thermal capacity of the suppression j
pool, the volume and temperature normally changes very slowly and monitoring these parameters daily is sufficient to establish any temperature trends.
By i
requiring the suppression pool temperature to be frequently recorded during periods of significant heat addition, the temperature trends will be closely followed so that appropriate action can be taken. The requirement for an external visual examination following any event where potentially high
{
loadings could occur provides assurance that no significant damage was encountered.
j In addition to the limits on temperature'of the suppression chamber pool water, operating procedures define the action to be taken in the event of i
safety-relief valve inadvertently opens or sticks open. As a minimum this l
action shall include: (1) use of all available means to close the valve, (2) initiate suppression pool water cooling, (3) initiate reactor shutdown when i
suppression pool average water temperature is 110 F* or greater, and (4) if i
other safety-relief vaives are used to depressurize the reactor, their i
discharge shall be separated from that of the stuck-open safety relief valve j
to assure mixing and uniformity of energy insertion to the pool.
3/4.6.3 PRIMARY CONTAINMENT ISOLATION VALVES Primary Containment Isolation Valves (PCIVs) form a part of the primary containment boundary. The PCIV safety function is related to control of primary containment leakage rates during accidents or other conditions to limit the untreated release of radioactive materials from the containment in excess of the design limits.
The automatic isolation valves are required to have isolation times within limits and actuate on an automatic isolation signal. The valves covered by this specification are listed with their associated stroke times, and other design information for lines penetrating the Primary Containment, in UFSAR Section 6.2.
The normally closed isolation valves are considered OPERABLE when manual valves are closed, automatic valves are de-activated and secured in their closed position, blind flanges are in place, and closed systems are intact.
Main steam lines through the isolation valves and hydrostatically tested valves must meet alternative leakage rate requirements. Other PCIV leakage rates are addressed by specification 3/4.6.1.1, " PRIMARY CONTAINMENT INTEGRITY". UFSAR Section 6.2 also describes special leakage test requirements and exemptions.
LA SALLE - UNIT 2 B 3/4 6-4 Amendment No. 98 J