ML20036B280
| ML20036B280 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 05/07/1993 |
| From: | Link B WISCONSIN ELECTRIC POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20036B281 | List: |
| References | |
| GL-90-06, GL-90-6, NRC-93-058, NRC-93-58, VPNPD-93-096, VPNPD-93-96, NUDOCS 9305180440 | |
| Download: ML20036B280 (7) | |
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Wisconsin i Electnc POWER COMPATH 231 W Mengan PC s> 20e.haaee vm2:n 9:u)2?t2:e VPNPD 93- 096 NRC 93- 058 May 7, 1993 Document Control Desk U.S.
NUCLEAR REGULATORY COMMISSION Mail Station P1-137 Washington, DC 20555 h
Gentlemen:
DOCKETS 50-266 AND 50-301 MODIFICATION TO TECHNICAL SPECIFICATION CHANGE REOUEST 145 PRESSURIZER PORV AND BLOCK VALVE REOUIREMENTS AND OVERPRESSURE MITIGATING SYSTEM OPERATIONS POINT BEACH NUCLEAR PLANT UNITS 1 AND 2 l
In accordance with the requirements of 10 CFR 50.4 and 50.90, Wisconsin Electric Power Company (WE), by letter dated May 30, 1991, requested amendments to Facility Operating Licenses DPR-24 and DPR-27 for Point Beach Nuclear Plant Units 1 and 2, respectively.
The purpose of the requested amendments was to implement in the Technical Specifications the provisions outlined in Generic Letter 90-06, for the Power Operated Relief Valves (PORV) and PORV block valves.
By letter dated January 25, 1993, j
the NRC staff indicated that the Technical Specifications, as proposed by us, did not completely implement the provisions of the generic letter, which had been justified as a backfit in accordance with 10 CFR 50.109.
The purpose of this letter is to amend our May 30, 1991, submittal to more completely implement the provisions of the generic letter.
We have made the following changes to the Specifications proposed in our May 30, 1991, submittal in response to the staff's comments:
1)
Proposed Specification 15.3.1.A.5.a(2) has been modified to implement the 72-hour allowed outage time for a PORV inoperable due to reasons other than seat leakage.
The proposed Specification reads:
"If one PORV is INOPERABLE due to causes other than excessive seat leakage, within one hour either restore the PORV to OPERABLE status or close its associated block h){) I iI}
170052 9305180440 930507 ADDCK0500g6 DR yg g
Document Control Desk Hay 7, 1993 Page 2 valve and remove power from the block valve.
If the PORV cannot be restored to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, then place the unit in a HOT SHUTDOWN condition within the next six hours.
2)
Proposed Specification 15.3.1.A.5.a(4) has been modified to implement the 72-hour allowed outage time for an inoperable PORV block valve.
This Specification reads:
"If one block valve is INOPERABLE, within one hour either restore the block' valve to OPERABLE status or place the associated PORV in manual control.
Restore the block valve to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
If these conditions cannot be met, place the unit in a HOT SHUTDOWN condition within the next six hours.
3)
Proposed Specification 15.3.1.A.5.a(5) has been modified to address the conditions in which both PORV block valves are inoperable.
This Specification reads:
"If both block valves are INOPERABLE, restore the block valves to OPERABLE status within one hour or place the associated PG2Vs in manual control.
Restore at least one block valve to OPERABLE status within the next hour.
If these conditions cannot be met, then place'the unit in a HOT SHUTDOWN condition within the next six hours.
4)
An explanatory footnote associated with Technical Specification Table 15.4.1-2, Item 28 concerning PORV testing has been added.
This footnote (14) reads:
" Required to be performed only if conditions will be established, as defined in Specification 15.3.15, where the PORVs are used for low temperature overpressure protection.
The test shall be performed prior to establishing these conditions."
Based on our review performed in response to the NRC staff's comments, we have made the following additional changes to our proposed specifications.
1)
The'following action statement, applicable to proposed Specifications 15. 3.1. A. 5. a (1) through 15.3.1.A.5.a(5) has been added to address required actions after placing an affected unit in hot shutdown.
This action statement reads:
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Document Control Desk
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May 7, 1993
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"If a unit is placed in the HOT SHUTDOWN condition in f
accordance with the requirements of Specifications a(1) through a(5) below, then the reactor coolant system i
temperature should be maintained greater than the minimum l
pressurization temperature for the inservice pressure r
test as defined in Figure 15.3.1-1.
If cooldown to less than this temperature is required in order to take action i
to restore the inoperable component (s) to service, then j
the requirements of Specification 15.3.15 apply."
l 2)
Proposed Specification 15.3.15.A.2.c has been modified to allow 32 hours3.703704e-4 days <br />0.00889 hours <br />5.291005e-5 weeks <br />1.2176e-5 months <br /> to depressurize and vent the reactor coolant system when both PORVs are inoperable and the low f
temperature overpressure protection system (LTOP) is required to be in service.
j 3)
The frequency for proposed Technical Specification Table 15.4.1-2, Item 28, for PORV testing has been changed.
The proposed frequency is:
"Each shutdown."
4)
Technical Specification Table 15.4.1-1, Item 29, l
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" Overpressure Mitigating," included a requirement in a note designated "****," that the PORVs be tested in i
accordance with the inservice test program required by the ASME Boiler and Pressure Vessel Code,Section XI.
i We have relocated this testing requirement from Table 16.4.1-1 and added it as Note 15 to Table 15.4.1-2.
I This note is applicable to the PORV testing required by Item 28.
t 5)
A minor change to the wording of proposed Specification 15.3.1.A.5.a(3) to state the removal of power from the PORV block valve as an action.
j We believe these modifications to our May 30, 1991, submittal are responsive to the concerns in your January 25, 1993, letter and implement the Technical Specification provisions requested in j
A complete copy of the Technical Specification pages included with our May. 30, 1991, letter, as modified by this submittal are attached.
The changes described above to our original submittal are indicated by a margin bar in the right hand margin.
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Document Control Desk May 7, 1993 Page 4 An evaluation of the acceptability of these changes to the PPNP Technical Specifications is also attached.
This evaluation supplements the evaluation provided with our May 30, 1991, submittal.
These proposed changes are additional restrictions and limitations not presently contained in the PBNP Technical Specifications.
We have reviewed this modification to our original submittal against the evaluations and no significant hazards determination included in May 30, 1991, request and have determined that the conclusions of our evaluations and the determination of no significant hazards remain applicable to that submittal as amended by this letter.
If you have any questions concerning this request, please contact us.
Sincerely, Bob Link Vice President Nuclear Power TGM/jg Attachments cc:
NRC Resident Inspector NRC Regional Administrator i
Subscribed and sworn to before me this lik day of Olau
, 1993.
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\\nrnauDL,.E]Mov G fot ryyPubl'ic, State of Wisconsin i
My' commission expires to - J 1-94
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EVALUATION j
MODIFICATION TO TECHNICAL SPECIFICATION CHANGE REOUEST I45 i
PRESSURI2ER PORY AND BLOCK VALVE REOUIREMENTS AND f
OVERPRESSURE MITIGATING SYSTEM d
i Generic Letter 90-06, " Resolution of Generic Issue 70, ' Power Operated Relief Valve and Block Valve Reliability,' and Generic Issue 94, ' Additional Low-Temperature Overpressure Protection for Light-Water Reactors,' Pursuant to 10 CFR 50.54 (f)," requested licensees to request amendments to the Technical Specifications i
j as proposed by the NRC staff.
Wisconsin Electric submitted proposed amendments by letter dated May 30, 1991.
The NRC staff l
requested, in a letter dated January 25, 1993, that we propose additional changes to the Technical Specifications to more completely implement the Specifications recommended in the i
i Generic Letter.
The 72-hour allowed outage time for corrective action was not l
1 included in our May 30, 1991, submittal for instances when a PORV
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way be inoperable for reasons other than seat leakage or for inoperable PORV block valves.
The 72-hour allowed outage time
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was included with the sample Technical Specifications attached to i
Therefore, we are revising our proposed i
Specifications to implement the 72-hour allowed outage time for those instances when a PORV is inoperable for reasons other than j
l excessive seat leakage, and to more completely address the j
instances when one or both PORV block valves are inoperable.
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This outage time is an additional restriction not presently
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included in the PBNP Technical Specifications.
This time is
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reasonable for taking corrective action consistent with the l
significance of an inoperable PORV or PORV block valve.
The i
PORVs are not a primary means for controlling reactor coolant system pressure, but may be used under post-accident conditions for depressurizing the reactor coolant system.
Restricting the time that a PORV or PORV block valve is inoperable provides added assurance that plant operation will remain in accordance with the safety analyses included in the PBNP Final Safety Analysis l
Report.
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Our original submittal did not include required actions beyond 5
placing an affected unit in hot shutdown when a PORV or block valve is inoperable.
With the structure of the PBNP Technical Specifications, this would require the application of 4
Specification 15.3.0, " General Considerations," after hot i
shutdown conditions are established.
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l Specification 15.3.0 requires placing the unit in cold shutdown
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within an additional 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after reaching hot shutdown.
The Low Temperature Overpressure Protection (LTOP) System.is required to be placed in service any time reactor coolant system temperature is less than the minimum temperature required for the inservice pressure test (3 60 *F).
Since LTOP also requires
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operable PORVs, it is desirable to maintain reactor coolant system temperature greater than this limit.
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f We have added an action statement applicable to all cases of inoperable PORVs or PORV block valves.
This requirement directs j
the operator to maintain reactor coolant system temperature j
greater than the LTOP enable temperature if possible.
Cooldown and operation at less than this temperature will be governed by j
the specifications governing operability of the LTOP system.
This is consistent with the Standard Technical Specifications for l
Westinghouse reactors.
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With reactor coolant system temperature greater than 360*F, LTOP is not required.
The pressurizer code safety valves i
d provide reactor vessel overpressure protection.
Therefore, maintaining reactor coolant system temperature above LTOP limits j
ensures the reactor coolant pressure boundary is protected from an overpressure event.
l Operation at temperatures less than 360*F with inoperable PORVs is limited by the requirements of Specification 15.3.15,
" Overpressure Mitigating System Operations."
Specification 15.3.15 requirements are consistent with Generic Letter 90-06 guidance and ensure an acceptable level of protection.
j We are also requesting a change to the proposed surveillance added to Technical Specification Table 15.4.1-2 as Item 28 for the PORVs to clarify when the surveillance is to be performed.
Generic Letter 90-06 requested licensees to cycle PORVs when shutdown prior to placing them in the low temperature overpressure protection mode of operation to ensure the valves would function when operated in this mode.
Our Specification as j
originally proposed would have allowed testing with the unit in cold shutdown which is not indicative of the conditions in which the valves may first be required to function.
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We have modified Item 28, and added a footnote (14) to the item, I
which explains the required tests should be done each shutdown I
prior to placing LTOP in operation.
Footnote 15 has also been added which requires the testing to be performed in accordance j
with the inservice test program.
Footnote 15 was previously located in Technical Specification Table 15.4.1-1 and is an existing requirement.
Present test procedures will allow testing during the applicable mode of operation.
This test provides added assurance of PORV operability.
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Specification 15.3.15.A.2 as originally proposed would have allowed only 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to depressurize and vent the reactor coolant system when both PORVs are inoperable and LTOP is in service.
l This time may not be adequate dependent on the actions necessary for venting the reactor coolant system.
These actions may include removing a PORV or safety from the system or opening i
steam generator or pressurizer manways.
We have proposed 32 hours3.703704e-4 days <br />0.00889 hours <br />5.291005e-5 weeks <br />1.2176e-5 months <br /> based on the guidance in Generic Letter 90-06 for a single i
During the short period of time that both PORVs are inoperable-l with LTOP required to be in service and the reactor coolant system not open to atmosphere, the residual heat removal (RHR) system will normally be in operation.
The RHR relief valve, located on the RHR suction piping which connects to the reactor coolant system hot legs, will limit reactor coolant system pressure.
The RHR system isolation valves do not receive an automatic isolation signal from the reactor coolant system.
Therefore, this relief valve will not be inadvertently isolated
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from the system.
l An addition to the bases of Section 15.3.15 has been made to specify the required vent path have an equivalent pressure relief i
capability of a PORV.
It also provides additional examples of l
e acceptable vent paths.
These changes, with the exception of the associated bases change, l
establish additional requirements and restrictions on the operation of PBNP.
These requirements provide added assurance l
that PORVs and PORV block valves remain operable and are available for use to control reactor coolant system pressure during normal and post-accident operations. -The proposed j
changes meet the intent of the criteria provided in NRC Generic i
Letter 90-06.
The proposed changes will enhance and ensure the i
safe and reliable operation of PBNP.
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