U-601141, Forwards Rev 4 to Pump & Valve Testing Program Plan, Per Ja Stevens 880121 Request for Addl Info Re Inservice Testing Program.Program Changes Due to Either Design Changes or Programmatic Improvements Listed in Attachment 4
| ML20196J562 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 03/08/1988 |
| From: | Spangenberg F ILLINOIS POWER CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML20196J567 | List: |
| References | |
| U-601141, NUDOCS 8803140400 | |
| Download: ML20196J562 (8) | |
Text
__- ____ _ _ _ _ _ _
(
U-601141 L30-88(03-08)-LP 1A.120 i
ILLINDIB POWER COMPANY CL4 TON PC%ER STAtl0N. P.O. Box 678. cLINTON. ILL1 Nots 61727 March 8, 1988 i
f Docket No. 50-461 j
Nuclear Regulatory Commission Document Control Desk Washington, D.C.
20555 i
Subject:
Clinton Power Station Inservice Testing Program
Dear Sir:
The letter from J. A. Stevens to F. A. Spangenberg dated January
[
21, 1988 (TAC No. 62989) requested additional information on the l
Inservice Testing (IST) Program.
Illinois Power's response to each question is in Attachment 1. is Revision 4 to the Pump and Valve Testing Program Plan which incorporates the responses in.
Revised Relief Requests are in Attachment 3, and the t
additional IST program changes due to either design changes or programmatic improvements are summarized for your convenience in l
If you have any questions, please contact me, r
Sincerely yours, 7
F. A. Span enberi p l
III Manager - icensig and S ety
[
l DW/ktm
]
Attachments cct NRC Clinton Licensing Project Manager j
f Regional Administrator, Region III, USNRC l
NRC Resident Office i
l Illinois Department of Nuclear Safety l
49 l
4!
I 8803140400 880308 l
i PDR ADOCK 05000461 4
P DCD l
I r
m-.+
-,-.,.,.-...,,,_._m._.._-_...__
_,_,,._,____,,,_,___,.,.,,_,e
Response to NRC Comments COMMENT #1:
There are many valves in the IST program that are identified to be tested at a cold shutdown frequency. The Code permits testing valves at cold shutdowns if it is impractical to test them quarterly and they are specifically identified by the These valves have been identified in the IST program and Relief Request owner.
No. 2016 details how the cold shutdown testing is to be performed, however, it is the NRC position that the licensee should provide technical justifications in which they explain why it is impractical to exercise these valves quarterly during power operations. These justifications should be part of the IST program to facilitate evaluacion by the NRC to determine if they agree that quarterly testing is in fact impractical. Provide the cold shutdown justifications for all valves or groups of similar valves that are identified to be tested on a cold shutdown frequency in the IST program.
RESPONSE
The cold shutdown justifications have been added to the IST program by reference to the appropriate IP submittel. To facilitate the retrieval of the document which explains IP's cold shutdown justification, a new column entitled "Cold Shutdown Justification" was added to the Pump & Valve Testing Program which references the applicable submittal.
COMMENT $2:
The licensee requested relief from measuring pump bearing temperatures (refer to Relief Request No. 3001) but did not propose any additional tcating to help determine pump mechanical condition. What alternate testing has been considered for evaluation of pump mechanical condition?
RESPOSSE:
Measuring pump bearing temperatures on an annual basis for pumps that are not normally inservice will require these pumps to operate for an additional two hours (or until the bearing temperature has stabilized). This additional operation time logs excessive hours on the pump's components with no expected benefits. Bearings tend to heat up immediately prior to failure.
For continuously operating pumps, routine bearing temperature monitoring may detect potential failures.
However, for pumps which only operate when tested (approximately 10-15 minutes), vibration readings, which are taken every quarter, are a more accurate tool for detecting possible failures. Therefore, no alternate testing is proposed.
I j
COMMENT #3:
i j
Relief from the allowable range requirements for pump flow rates and differential i
pressures cannot be granted on a general basis (refer to Relief Request No.
{
3006). The Code allows the owner to specify reduced ranges if the Code limits l
cannot be met for specific pumps in the IST program, however, the NRC does not i
agree with a general relief to relax liuits for all pumps in the program. A l
general relief request could relax limits for pumps that normally fall well i
within the Code specified ranges, therefore, there would be no justification for not complying with the Code for those pumps.
DAP/ISIl/l i
RESPONSE
Illinois Power believes that the general relief requested from ASME section XI Code requirements with regard to allowable ranges for pump flow rates and differential pressures is appropriate for all pumps within the CPS ISI Progran.
The justification for revising the allowable range requirements for flow and differential pressure is based on the fact that the ranges in the Code are too restrictive. It should be noted that IP has not revised the low end of the ranges. By revising only the high end, the number of, test failures due to the pump producing "too much" flow or differential pressure will be reduced. We continue to believe that the Code-specified ranges are impractical. This is corsistent with ASHE Standard OM-6 which was recently approved by the ASME Board of Nuclear Codes and Standards and allows the differential pressure or flow to reach up to 110% of the baseline value before it is in the Action Range. This OM Standard, although it has not been approved by the NRC, is an indication of industry consensus and experience wifa pump testing.
COMMENT #4:
Relief Request No. 3004 does not provide sufficient information for using pump discharge pressure to evaluate pump hydraulic performance for the shutdown service water pumps instead of differential pressure. The justification showed that the normal lake level variations over the past three years are small enough that the licensee can adequately monitor pump hydraulic degradation by using pump discharge pressure and flow rate, however, provisions should be made to calculate pump differential pressure if the lake level goes out of a specified range (i.e.
69113 feet). Also, the relief request should provide the allowable ranges of pump diucharge pressure for our review or it should specifically state that the Code allowable ranges for differential pressure are applied to the discharge pressure r.easurements.
RESPONSE
Relief Request No. 3004 has been deleted. The CPS surveillance procedure will be revised to calculate the differential pressure in accordance with Relief Request 3006 discussed in comment #3, above.
COMMENT iS:
Do the pump flow rate calculations being performed on the standby liquid control pumps and diesel fuel oil transfer pumps meet the accuracy requirements of IWP-41107 If not, this should be addressed in the appropriate relief requests.
RESPONSE
Relief Request 3002 has been revised due to the fact that the calculation and gauges used for the diesel fuel oil transfer pumps do not meet the accuracy requirements o." IWP-4110. As these pumps have had relatively inconsistent data, new limits were prepared which base the limits on the design of the engine and fuel oil pump. The numbers used are more conservative than the above requirements to account for the in-ccuracies used to calculate flow.
DAP/ISI1/2
-)
The intent of Relief Request 3003 on the standby liquid control pumps was to also request relief from IWP-4110. A revised relief request has been prepared to clarify.
COMMENT #6:
Relief Requeat No. 1002 is too general and is, therefore, unacceptable in its current form. We agree that testing should not be performed that would place the plant in a situation where it would bc required to change the plant mode (i.e.
shutdown) or enter an LCO with a short action statement where adequate time would r.ot be available to correct a problem if a component failed during testing.
However, entering an LCO is not an adequate justification by itself for not performing required testing.
RESPONSE-Relief F.equest 1002 was expanded to clarify IP's position that we will not change the plant mode or enter an LCO with an action statement of less than 12 nours to perform testing.
COMMENT #7:
Relief Request No. 2001 does not provide sufficient information for not testing feedwater header check valves quarterly or during cold shutdowns.
The relief request should include a more detailed technical justification that provides information such as an explanation of how interrupting flow could severely affect plant operation. Also, the relief request should more clearly explain why these valves cannot be exercised closed during cold shutdowns.
RESPONSE
Relief Request No. 2001 has been deleted.
Further review and discut sions with the Operations Department has concluded that these valves can be tested during cold shutdowns. Interrupting feedwater flow to the reactor during power operation is not feasible without reducing power. The feedwater check valves, during power operation, are also located in a high radiation area.
For the above reasons, the testing requirements in the applicable CPS surveillance procedures for these valves will be revised to test on a cold shutdown frequency.
COMMENT #8:
Provide a more detailed technical justification for not exercising valve IC11-F122 during cold shutdowns (refer to Relief Request No. 2002). Can the reactor recirculation pumps be stopped during cold shutdowns?
RESPONSE
Valve ICll-F122 supplies water to the reactor recirculation pumps and the Control Rod Drives (CRDs). The reactor recirculation pumps could be stopped during cold shutdowns to allow testing of this valve. However, these pumps are normally run during cold shutdowns to continue recirculating the inventory in the vessel.
i This recirculation is considered "beneficial" for stabilizing the vessel temperature. As this valve also supplies drive water to the CRDs, closing this valve would create a void in the CRDs which would require extensive venting to remove the air from the CRD system. This venting results in a loss of reactor l
l DAP/IS11/3 1
?
coolant which must be processed through the radwaste system.
In addition, the venting process is very time consuming which could extend the outage. Based on the above, this valve will be tested during refueling outages.
Relief Request No. 2002 was revised to clarify the technical justification.
C0KKENT #9:
The justification in Relief Request No. 2003 states that injecting plant demineralized water at normal temperatures during cold shutdowns would cause thermal transients that could damage various reactor protection system instrumentation. What is the basis for this statement? How much of a differential temperature is necessary to cause thermal shock damage to these components?
RESPONSE
Relief Request No. 2003 has been deleted.
Further review of the design of these valves has determined that it is possible to use a mechanical exerciser to test these valves during cold shutdown, thereby avoiding any potential for thermal transient.
Illinois Pover's cold shutdown justification for not testing during power operation is that both trains of the Standby Liquid Control System (SLC) would have to be declared inoperable.
It is impractical to declare the SLC systen inoperable due to the limitations imposed by the Technical Specifications, i.e.,
"be in at least HOT SHUIDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />." These valves are also in a hostile environment during power operation.
COMMENT #10:
What r' ternate methods have been evaluated to detect degradation of valve 1E12-1 35 (refer to Relief Request No. 2007)?
RESPONSE
The review of the design of this valve concluded that no alternate methods are available to detect valve degradation. Detecting valve degradation requires i
(
monitoring stroke time which is not possible for this valve. This valve operates simultaneously with another,alve and does not have any position indication or other means available to monitor valve stroking. For this reason Illinois Power does not plan to do any further testing than as stated in Relief Request 2007.
COMMENT #11:
Relief Request No. 2008 states that valves 1G33-F052A and B will be disassembled and inspected on an alternating basis during refueling outages. A sample disassembly program is an acceptable testing method as long as it complies with the NRC guidelines for sample disassembly of check valves and the appropriate features of these guidelines are stated in the relief request.
The NRC staff guidelines on sample disassembly and inspection are:
J DAP/ISII/4
a.
Valve sample disassembly and inspection utilizing a manual full-stroke exercise of the valve disk is an acceptable method to verify a check valve's full-stroke capability and/or its reverse flow closure capability. This program involves grouping similar valves together and testing one valve in each group during each refueling outage. The sampling technique requires that each valve in the group be of the same design (manufacturer, size, model number and materials cf construction) and have the same service coaditions. Additionally, at each disassembly it must be verified that the disassembled valve is capable of full-stroking snd that its internals are structurally sound (no loose or corroded parts).
b.
A different valve of each group is required to be disassembled, inspected and nanually full-stroke exercised at each refueling outage, until the entire group has been tested.
If it is found that the disassembled valve's full-stroke operability is in question, the remainder of the valves in that group must also be disassembled, inspected and manually full-stroke exercised during the same outage.
RESPONSE
Relief Request No. 2008 has been revised to comply with the above NRC guidelines.
COMMENT #12:
Provide a more detailed technical justification for not exercising the valves identified in Relief Request No. 2009 during cold shutdowns. The fact that this testing requires a lot of time is an inconvenience but it is not an adequate basis for not testing the valves at a cold shutdown frequency.
RZSPONSE:
Relief Request No. 2009 has been revised to include further justification for not testing these valves during cold shutdowns.
There are two alternatives which could be utilized to perform the testing. The first method would require the Control Room HVAC System to be declared inoperable. This method floods the charcoal beds rendering them inoperable. The beds must then be replaced.
Replacing the beds is very time consuming, requiring a minimum of 2-3 weeks and expensive due to cost of replacement charcoal, added testing and required manpower.
The second test method would require the shutdown service water A and B subsystems to be inoperable.
Taking these subsystems out of service would make the Residual Heat Removal (RH) system inoperable.
In this situation, there is no available mechanism for removing decay heat. Therefore, this testing is not just an inconvenience but is impractical during cold shutdown.
COMMENT #13:
Provide a more detailed technical justification for not exercising valves lE12-F050A and B during cold shutdowns (refer to Relief Request No. 2010). Are both trains of shutdown cooling required to be in operation? Why can't these valves be exercised during the shutdown cooling mode of RHR operation?
DAP/ISI1/5
RESPONSE
Relief Request No. 2010 has been deleted.
Based on further review and discussions with the Operations Department, these valves can be tested during cold shutdowns. These valves are part of the Residual Heat Removal (RHR) shutdown cooling supply to the vessel. As this mode of RHR is normally in use during cold shutdowns and refuelings, the exercise requirements for these valves can be satisfied.
Our justification for not testing these valves during power operations is that these valves are pressure isolation valves. Testing these valves during power operation would result in a loss of one isolation barrier between the high pressure and low pressure piping.
Therefore, the testing requirements for these valves will be revised to exercise during cold shutdown.
COMMENT #14:
Provide the technical justification for not utilizing system flow to exercise the valves affected by Relief Request No. 2014 quarterly during power operations or during cold shutdowns.
RESPONSE
To test the valves listed in Relief Request No. 2014 with flow would require the initiation of the Emergency Core Cooling System (ECCS).
Injecting this water during normal operation is not practical as an undesirable power transient would be caused by the large increase in cooling water to the vessel.
Injecting this water during cold shutdowns would degrade the chemistry of the reactor coolant to the extent that additional radwaste would be generated in cleaning up the reactor coolant system.
CCMMENT #15:
The information in Relief Request No. 2016 can be stated elsewhere in the IST program.
Relief is not necessary because the licensee's proposals for cold shutdown testing conform to the Section XI requirenents and/or the NRC staff positions.
RESPONSE
Relief Request No. 2016 was deleted.
The text of the Pump & Valve Testing plan was revised to include this information.
COMMENT #16:
How long can the reactor water cleanup system be out of service without substantially degrading reactor coolant chemistry during cold shutdowns? How l
long does it take to exercise the valves addressed in Relief Request No. 20177 DAP/ISII/6
RESPONSE
It is our experience that with the Reactor Water Cleanup (RT) out of service the Technical Specification limit will be reached in approximately four or five days.
'filinois Power Company's procedural linit would be reached in one or two days.
However, we believe that removing the RT system from operation for any length of time should be limited, except in cases of equipment failures or other extenuating circumstances. Allowing the quality of the reactor coolant to degrade any amount is not considered desirable and should be restricted.
Therefore, Illinois Power will stroke test these valves only during refueling outages. Testing of these valves would require a minimum RT outage of three shifts, approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
COMMENT #17:
Provide a more detailed technical justification for not exercising valve IE12-F475 quarterly during power operations or during cold shutdowns (refer to Relief Request No. 2018).
RESPONSE
As discussed in Relief Request No. 2018, this valve cannot be exercised during normal operation or cold shutdowns because it is located on a line pressurized by either the reactor recirculation system (RR) or the residual heat removal system
( RHR). As this valve is not designed to open against pressure, the valve cannot be tested in these modes. This valve is installed to protect against thermal over-pressurization. Due to the length of the refueling outages, both the RHR and RR systems can be isolated to enable this valve to be tested.
COMMENT #18:
Provide a more detailed technical justification for not measuring the operating torque for the valves addressed in Relief Request No. 2019 quarterly during power operations or during cold shutdowns.
RESPONSE
Relief Request No. 2019 has been deleted. The valves will be stroked quarterly in accordance with th, Code requirements.
DAP/ISII/7
__