ML19296D931

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Responds to NRC 800122 Request for Info Re Effects of Certain Valve Lineup Procedural Changes.Adverse Safety Impacts Exist Re Plant Operation W/Motor Operated Valve in Open Position.Leakage Can Be Checked W/Valve Closed
ML19296D931
Person / Time
Site: Crystal River Duke Energy icon.png
Issue date: 03/10/1980
From: Richard Bright
FLORIDA POWER CORP.
To: Reid R
Office of Nuclear Reactor Regulation
References
3--3-A-3, 3-0-3-A-3, NUDOCS 8003130551
Download: ML19296D931 (3)


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Florida Power CO R PO H A T *0 N g/

March 10, 1980

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File: 3-0-3-a-3 Mr. Robert W. Reid Chief Operating Reactors Branch #4 Division of Operating Reactors U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

Request for Information on the Effects of Certain Valve Lineup Procedural Changes (Letter dated 1/22/80 to J. A. Hancock from R. W. Reid)

Dear Mr. Reid:

In response to the subject letter, the following information is being provided:

1. What is the adverse safety impact of starting up the plant with the MOV in the open position?

With this MOV in the open position, isolation of the Reactor Coolant System (high pressure) from the Decay Heat System (low pressure) is maintained by two (2) check valves. If leakage past both check valves occurs, one train of the Decay Heat System will begin to increase in pressure. Pressure would in-crease until the relief valve (DHV-17 or DHV-28) setting in that train is exceeded. At that time, reactor coolant would be relieved into the decay heat pit sump. This event would be considered an unplanned release of airborne contaminates which would create a hazard to personnel in the area.

If the leakage rate past both check valves approaches or ex-weds the relief capacity (31.5 GPM) of the relief valve in that train, the potential exists to over-pressurize that decay heat train and a possible pipe rupture. During startup, this condition may be controlled in time to prevent equipment dam-age.

8003130 5 5 General Office 320 inirty fourtn street soutn . P O Box 14042. St Petersburg. Florca 33733 813-866-5151

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Mr. Robert W. Reid Page Two March 10, 1980 With the MOV in the closed position during startup, pressures can procedurally be monitored upstream of this valve by use of a pressure gage between the Reactor Building penetration and the MO V. Increasing gage pressures while increasing Reactor Coolant System would indicate both check valves are leaking and appropriate action would be initiated.

2. What is the adverse safety impact of operating the plant with the MOV in the open position?

The hazards involved with operating the plant with the MOV open are identical to those stated in Question 1. Probability of Decay lieat System over-pressurization is increased due to the time required to lower the Reactor Coolant System pressure to reduce check valve leakage. Reactor Coolant System pres-sure could not be controlled quick enough to prevent a Decay Heat System over-pressurization.

Operating the plant with the M0V in the closed position would prevent these hazards. Leakage past both check valves can be detected by monitoring a pressure gage which indicates the pressure between the last check valve and the MOV. Procedur-ally, this gage would be monitored on a regular basis and be-fore the quarterly ISI stroke testing of the MOV.

Answers to these two questions have indicated there are adverse safety impacts related to plant operation or startup with the MOV open. With the MOV closed, check valve leakage can be monitored by procedurally re-quiring pressures behind the M0V to be monitored before operation of the MO V.

If you have any questions concerning the subject of this letter, please contact this office.

Very truly yours, FLORIDA POWER CORPORATI0t1

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Ronald M. Bright Acting Manager riuclear Support Services RMBemhM0106

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STATE OF FLORIDA COUNTY OF PINELLAS R. M. Bright states that he is the Acting Manager, Nuclear Support Services, of Florida Power Corporation ; that he is authorized on the part of said company to sign and file with the Nuclear Regulatory Connission the information attached hereto; and that all such statements made and matters set forth therein are true and correct to the best of his knowledge, information and belief.

f k R. M. Bright Subscribed and sworn to before me, a Notary Public in and for the State and County above named, this 10th day of March,1980.

Notary Public Notary Public, State of Florida at Large, My Coninission Expires: August 8, 1983 Cameron (Notary)