ML20023D885
| ML20023D885 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 05/31/1983 |
| From: | Toner K CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8306060119 | |
| Download: ML20023D885 (4) | |
Text
e Consumers Power Company Gerieret officos: 1945 West Parnell Road, Jeckson, MI 49201 e (517) 788-0550 May 31, 1983 Dennis M Crutchfield, Chief Operating Reactor Branch No 5 Nuclear Reactor Re;ulation i
US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-155 - LICENSE DPR BIG ROCK POINT PLANT - ENVIRONMENTAL QUALIFICATION OF SAFETY-RELATED ELECTRICAL EQUIPMENT - RESPONSE TO THIRTY (30) DAY REQUEST The NRC in a letter dated April 26, 1983 submitted the Safety Evaluation Report (SER) and the Technical Evaluation Report (TER) for the Environmental Qualification of Safety Related Electrical Equipment for the Big Rock Point Plant. The staff requested in the SER that Consumers Power Company reaffirm the justification for continued operation (JCO) and within thirty (30) days of receipt of the SER, submit information for items in NRC Categories I.B. II.A and IV for which JC0 was not previously submitted to the NRC. This letter responds to this request.
Consumers Power Company has determined that additional JC0 is not required since no new equipment has been added to the Big Rock Point Plant. Therefore, with the exceptions noted below, the JC0 provided in our April 30, 1982 submittal is still valid.
It should be noted that a comprehensive review program is being conducted for items in NRC Categories I.B and II.A and will be scheduled as part of our integrated assessment program which will be described in our upcoming June 1, 1983 submittal. (Pleace note that items in NRC Category IV are precluded from the scope of our review program since the TER did not identify any open items.)
As a result of our review of the JC0 provided in Consumers Power Company letter dated April 30, 1982 for motor-operated valves: M0-7051, M0-7061, M0-7070, M0-7071, M0-7064 and M0-7068, an error was found concerning the operability times of these valves. Specifically, Consumers Power Company failed to address the need for these valves to close when entering the recirculation mode following core spray actuation.
Big Rock Point Plant emergency procedures require the operator to isolate containment sprays (M0-7064, M0-7068) and one core spray line to ensure adequate core spray flow to the core spray train in-service. This transfer to the recirculation mode can occur between four and 21 hours2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br /> following the break event. Accordingly, please replace the applicable JC0 statements documented in our April 30, 1982 submittal with the following statements. We plan to update the Big Rock Point EEQ Book and submit it to the NRC.
g OC0583-0029A-NLO2 8306060119 830531 DR ADDCK 05000155 j O PDR
DMCrutchfis1d, Chief 2
Big Rock Point Plant EEQ - 30 DAY RESPONSE May 31, 1983 MO-7051 and M0-7061 The unqualified equipment will have performed its safety function prior to failure.
As outlined in the summary section of the discussion on Containment Atmos-pheric Conditions, core spray actuation occurs within 2.5 minutes following a large or intermediate break event. For small breaks, core spray occurs immediately following Reactor Depressurization System (RDS) actuation.
Conditions prior to depressurization are significantly less than design parameters due to limited exposure to the harsh containment environment.
Upon entering the recirculation mode, four to twenty-one hours following a break, closure of M0-7051 or M0-7061 may be necessary if the break occurs in the high energy side of the primary core spray line. Closing one out of two valves (M0-7051 or M0-7061) would be necessary to ensure long term adequate core spray flow.
An actuator of the same type used on an M0-7051 and MO-7061 successfully completed a LOCA simulation. Testing for radiation or thermal aging qualifi-cation for this type of actuator has not been done; however, most component materials used in the actuator and motor can withstand a threshold damage of at least 4.0 x 106 RADS.
Since the valves (M0-7051 and MO-7061) are not required to operate beyond a twenty-one hour time period, the safety function performed by these valves would have been executed before prolonged exposure to the harsh environment could conceivably result in their failure.
MO-7064 The unqualified equipment will have performed its safety function prior to failure.
As outlined in the summary section of the discussion on Containment Atmos-pheric Conditions (ie, for steam line breaks requiring containment spray) actuation occurs shortly following the event when containment environment has not degraded significantly. M0-7064 is not located in the steam drum cavity; the area which experiences the temperature rise during the steam line break.
Upon entering the recirculation mode, four to twenty-one hours following a break, closure of M0-7064 is necessary to ensure adequate core spray flow. An actuator of the same type used on MO-7064 has successfully completed a LOCA simulation. A test for radiation and thermal aging was conducted on actuator units similar to the type used on MO-7064. Based on the results of these tests, we conclude that the environmental conditions are less than design due to successful actuation of containment spray. Since M0-7064 is not required to operate beyond a twenty-one hour time period, the safety function of M0-7064 would have been performed before prolonged exposure to the harsh environment could conceivably result in its failure.
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4 DMCrutchfield, Chief 3
Big Rock Point Plant EEQ - 30 DAY RESPONSE May 31, 1983 MO-7070 and MO-7071 The unqualified equipment will have performed its safety function prior to failure.
I,.
As outlined in the summary section of the discussion on Containment Atmos-pheric Conditions, core spray actuation occara within 2.5 minutes following a large or intermediate break event. For small breaks, core spray occurs immediately following RDS actuation. Conditions prior to depressurization are significantly less than design parameters due to limited exposure to the harsh i
containment environment.
When entering the recirculation mode, four to twenty-: 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> fc11owing a break, the Emergency Operating Procedure (EMP 3.3) in acts the operator to close the backup core spray line valves (110-7070 and L A 071). Hcwever, if the break has occurred in the high energy cide of the primary core spray line, the backup core spray line is utilized to provide core cooling and the primary core spray valves are closed. MO-7070 and M0-70f1 wculd remain open to ensure j
long term adequate core spray flow.
The motor operators for M0-7070 and;M0-7071 are to be replaced in the 1983 refueling outage with Rotork actuators, Model Number 14NA1. Since these actuators are qualified via type testing, the safety function of these valves (M0-7070 and M0-7071) would be performed.
MO-7068 The unqualified equipment will have performed its safety function prior to failure.
As discussed in the summary paragraph on Containment Atmospheric Conditions, i-actuation of Primary Containment Spray (M0-7064) would occur shortly following a steam line break, and before containment environment has significantly degraded. Should the unlikely failure of M0-7064 occur at this time, secondary containment spray (MO-7068) would be manually actuated immediately.
When entering the recirculation mode, four to twenty-one hours following a break, closure of the secondary containment spray valve (M0-7068) is necessary to ensure adequate core spray flow.
An actuator of the same type used on MO-7068 has successfully completed a LOCA i
simulation. Testing for radiation or thermal aging qualification for this type of actuator has not been done; however, most component materials used in the actuator and motor can withstand a threshold damage of at least 4.0 x 106. RADS.
Since the environmental conditions are less than design due i
OC0583-0029B-NLO2 I
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DMCrutchfield, Chief Big Rock Point Plant EEQ - 30 DAY RESPONSE May 31, 1983 4
to successful actuation of containment spray and the valve is not required to operate beyond a twenty-one hour time period, the safety function of MO-7068 would have been performed before exposure to the harsh environment could conceivably result in its failure.
It should be noted that the secondary containment spray is a redundant system.
f(
col W Kerry A Toner Senior Licensing Engineer CC Administrator, Region III, USNRC NRC Resident Inspector - Big Rock Point i
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