ML18044A666
| ML18044A666 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 03/18/1980 |
| From: | Hoffman D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8003210398 | |
| Download: ML18044A666 (3) | |
Text
consumers Power
- company General Offices: 212 West Michigan Avenue, Jackson, Ml~hlgan 49201
- Area Code 517 788-0550 March 18, 1980 Director, Nuclear Reactor Regulation Att Mr DennisL Ziemann, Chief Operating Reactors.Branch No 2 US Nuclear Regulatory Commission*
Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT -
LWR COOLANT SYSTEM ISOLATION VALVES RESPONSE Consumers Power.Company was requested by letter.dated February 23, 1980 to address* questions concerning Primary.Coolant System (PCS) pressure isolation valves.
The design examined by the Reactor Safety Study (WASH-1400) for these isolation. valves contained two in-series check valv.es isolating* the high-
. Pressure PCS from the Low-Pre$sure Injection System (LPIS) piping.
Our response to these questions are as follows:
Question 1 Describe the valve configuration at your* plant and indicate if an Event V isolation valve configuration exists within the Class I boundary of the high pressure piping connecting PCS piping to low pressure system piping; e.g.,
(1) two check valves in series, or (2) two check valves in series with a MOV.
Response To Question 1 The Palisades Plant do~s not have* an Event V isolation valve configuration as described in Figure 1 of the NRC lette~ dated February 23, 1980'; l).owever, the following valve co~figurations were*reviewed:
- Low-Pressure. Safety Injection (LPSI)
- Charging
- High..:Pressure Safety Injection (HPSI)
Other systems are connected to the PCS but are isolated by the containment
- isolation signal and were, therefore, excluded from this review.
- Joo/
Both the Charging and HPSI Systems consist of high-pressure piping between the S/
pumps and the PCS and do not fall within the scope of the NRC February 23,
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2 Should flow occur from the PCS into the safety injection p1p1ng as a result of check Valve "A" leaking (Attachment 1), the pressure in the safety injection piping would increase until the set point of the pressure indicator-controller (PIC) is reached.
Valve "B" would automatically open to relieve this pres-sure:
The PIC, which is located in the control room, provides pressure indication as the pressure in the pipe approaches the PIC set point..
Addi-tionally, the level, pressure and temperature changes in the quench tank would be annunciated in the control room.
In the event that check Valve "C" and motor-operated Valve "D" leak, the safety injection (SI) tank pressure would decrease.
This would be.observed by the pressure transmitter (PT) readings outside containment and the display in the control room.along with alarm annunciators.
Question 2 If either of the above Event V configurations exist at your facility, indicate whether continuous surveillance or periodic tests are being accomplished on such valves to ensure integrity.
Als.o indicate whether valves have been known, or found, to lack integrity.
Response To Question 2 Surveillance is performed to verify the seating of check Valve "A."
This surveillance is conducted during each plant start-up from cold.shutdown by observation of the PIC.
Use of the PIC allows for a continuous pressure monitoring on the low-pressure side of the subject check.valves.
The PCS isolation check valves have not caused any significant integrity problems.
Question 3 If either of the above Event V configurations exist at your facility, indicate whether plant procedures should be revised or if plant modifications should be made to increase reliability.
Response To Question 3 Based on the review conducted to answer the above questions, there are not any modifications nor additional surveillance programs needed to verify the opera-tion of the in-series check yalves isolating the high-pressure PCS from the LPIS piping for the Palisades Plant.
JJ~C? M!J--c---
David P Hoffman Nuclear Licensing Administrator CC JGKeppler, USNRC Enc Attachment I
4sv
~1 1 To l
Attac:b.ment l SI Tank V'1-}HPSI
-i R:d undant
(One injection path:
typical of four R~f d.rawJngs M-203 ~d M-204).
E/P:
PIC:
PT :
sv :.
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- electro-pnetllllatic transducer pressure indicator/controller pressure trans1IUtter solenoid valve
- nonne.lly closed valve PT