ML20151N033
| ML20151N033 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 04/19/1988 |
| From: | Boger B Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20151N037 | List: |
| References | |
| NUDOCS 8804250183 | |
| Download: ML20151N033 (7) | |
Text
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7590-01 UNITED STATES OF AMERICA NUCLEAR REGlfLATORY COMMISSION
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In the matter of
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Docket No. 50-293
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BOSTON EDISON COMPANY
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(PILGRIM NUCLEAR POWER STATION)
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EXEMPTION I.
The Boston Edison Company (BECo), the licensee, is the holder of Operating License No. DPR-35 which authorizes operation of Pilgrim Nuclear Power Station.
The license provides, among other things, that the Pilgrim Nuclear Power Station is sub.iect to all rules, reculations, and Ordars of the Commission now or hereafter in effect.
The olant is a boiline watar reactor at the licensee's site locattd in Plymouth County, Massachusetts.
II.
On November 19, 1980, the Conmission published a revised Section 50.48 and l
a new Appendix R to 10 CFR Part 50 regarding fire protection features of nuclear power plants (45FR76602).
The revised Section 50.48 and Appendix R became effective on February 17, 1981.
Section !!! of Appendix R contains 15 l
subsections, lettered A through 0, each of which specifies requirements for a particular aspect of the fire protection features at a nuclear power plant.
One of these subsections, I!!.G.I.lal, is the subject of the licensee's exemption reouest.
8804250183 900414 PDR ADOCK 05000293 p
c.
7590-01
-2 Section III.G 1.(a) of Appendix R.to 10 CFR Part 50, requires that fire protection features be provided for structures, systems, and components important.to safe shutdown.
The feate/es are required by regulation to be l
capable of limiting fire damage such that at least one train of each system necessary to achieve and maintain hot shutdown from either the Cnntrol Room or emergency control station (s) is free of fire damage without the need for operator actions classified as repairs.
III.
By letter dated October 2, 1987, BEco, requested exemptions from 10 CFR Part 50, Appendix R, Item !!I.G.1.(al requirement, for performing repairs for naintaining plant hot shutdown following a fire in any one of certain plant l
Specifically, the licensee proposes replacing fuses in the control ereas.
circuits for RHR valves in the torus cooling mode of RHR operation which may get blown due to a fire in Fire Area (FA) 3.1 (Control Room), 3.2 (Cable Spreading Room) or 1.'9 (Reactor Ruilding Elevation ?3', East side).
Additionally, the licensee proposes installing a jumper wire in the control l
circuit for a required coolina fan that may get disabled due to a fire in 1
FA 1.9.
The licensee indicated that for a fire in FA 3.1 or 3.2, the Reactor Core Isolation Cooling (RCIC) and Residual Heat Removal (RHR) in the torus cooling node will be used to achieve and maintain safe shutdown.
The licensea alsc indicated that for a fire in FA 1.9, the RHR in the torus cooling mode can be used with other applicable systems to achievo and maintain safe shutdown.
The licensee, I
however, identified an electrical isolation deficiency associated with the torus cooling node of RHR operation which could compromise the capability to traintain 1
7590 n1 3-hot shutdown following cartain fire evants.
Specifically, the licensee's analysis of postulated fires in plant areas indicated that a fire in any one of 3 # ire areas (FA 3.1, 3.? or 1.9) can cause damage to the renote control circuits for the 5 valvos required for tcrus cooling.
This damage could result in blowirg the associated control power fuses that are common to both the remote and local control circuits for these valves and consequently compromise the local control capability for these valves.
Since this event.could blow fuses in both divisions, this would not conform to Appendix R, III.G.I.
The transferrino of the control of the needed valves from the control room t
to a local control station (i.e., alternate shutdown panel) will not ne sufficiant to ensure local control of these valves.
Control would be lost if their comon fuses ara blown prior to such transfer. To ersure local control of the'5 valves, the licensee proposes to replace the blown control power fuses for the affected valves in a timely manner after effecting the transfer of the I
5 velvas to local control.
Specifically, for a fire in any one of tha above 3 areas, the licensee proposes to transfer control of the needed valves from the control room to an alternate shutdown panel (ASP) located in a fire area l
different from the affected fire area using the respectiva transfer switches for the valves on the paael arid replace the blown fuses at the MCC located adjacent to the ASP, One of two sets (i.e., each set containing one ASP ano one adjacent MCC) associated with the valves of the corresponding train of two RHR trains will be utilized depending upon the fire location. One of these sets is located in FA 1.9 and the other is located in FA 1.10 (Reactor Pauilding Elevation 23', k'est side).
For a fire in FA 3.1 or 3.?, the licensee will usa either of these sets; for a fire in FA 1.9, the set located in FA 1.10 I
1 L
7590-01
. will be used.
At any one time, no more than 5 fuses will need to be replacad and the need for replacement will be identified by the absence of indicating lights above the respective control switches for the valves.
The licensee has indicated that sufficient time will be available for replacing the blown fuses since thev have confirmed that a single operator can replace 5 fuses within 20 minutes. General Electric Company (GE) has determined that at least 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> are available to perform these replacements before torus cooling will be required.
The fuses are correctly sized and clearly marked for use and all necessary tools and additional spare fuses will be maintained nearby. Adaquate lighting has been provided for the MCC cubicles containing the fuses to facilitate fuse replacement, in this context, the staff notes that the fuse replacement will not result in undue operator hazard since it involves only control power fuses.
The licensee indicated that a fire in FA 1.9 can additionally disable control of a fan which, in turn, will disrupt the cooling of the area in the Reactor Building hcusing various needed hot shutdown components. The licensee has calculated that 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after loss of area cooling, the area temoerature can rise to 209'F, the value established for environmental qualification for the equioment in the area.
The licensee proposes to install a jumper wire l
(hot shutdown repair) in the fan control circuit at tne applicable MCC l
(located in FA 1.10) which is outside the affected fire area.
Sufficient time will be available for the.ivmper wire installation since the task can be S
completed in less than one hour.
The licensee further indicated that the properly sized jumper will be kept in one of the alternate shutdown tool l
boxes (located in switch gear rooms),
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7590-01
- The licensee has committed to implement the above procedures prior to plant startup from the current refueling outage (RF0) No. 7.
The procedures i
for plant shutdown outside the control room (at the ASP) include all actions to be taken for fuse replacement, when they are to be taken, and identify the MCC and the breaker number for each comonnent whose fuse may require replacement.
Supplemental procedures on post-fire shutdown in specific areas includino the Reretor Buildino are oeino developed (to be complated and s
implemented prior to plant startup from RF0 No. 7).
These will give instructions to the operators as to when and how to install the jumper wire.
The licensee committed to train the operators in the above procedures prior to startup.
The manual actions including the hot shutdown fuse replacement, meet tha intent and purpose of IE Information Notice No. 85-09, "Isolation Transfer Switches and Post-Fire Shutdown Capability " dated January : 1, 10A5.
The staff has further determined that the other proposed hot shutdown repair l
requirina jumper wire installation to facilitate parformance of a support I
function (cooling an area to maintain hot shutdown) can be comoleted in a timeh manner so as not to compromise maintaining hot shutdown.
Based on the above evaluation, the staff concludes that application of the reculation in these particular circumstances is not necessary to achiave the underlying purpose of Appendix R to 10 CFR Part 50.
The licensee's I
existing fire protection configuration, including the proposed manual actions, provides an equivalent level of protection to that achieved by compliance with Section III.G.1(2) of Appendix R.
Therefore, the licensee's request for an exemption to the requirements of Section III.G 1 (a) of Appendix R in relation to the need of manual actions including the above hot shutdown repairs should be granted.
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7590-01 6-IV.
Accordingly, the Commission has determined, pursuant to 10 CFR 50,12(a), that (11 the exemption as described in Section III is authorized by law, will not present an undue risk to the public health and safety. and is consistent with the comon defense and security and (2) in this case, special circumstances are present in that application of the regulation is not necessary to achieve the underlying purpose of Appendix R to 10 CFR Part 50. Therefore, the Comission hereby grants the exemption from the requirements of Section III.G.I.(a) of Appendix R to 10 CFR Part 50 regarding the ability to achieve and maintain hot shutdown from either the Control Room or emergenc!
control station (s) without the need of operator actions classified as repairs.
Pursuant to 10 CFR 51.32, the Comission has determined that the granting, of this exemption will not result in any significant environmental impact
( 53 FR12484 ).
A copy of the licensee's request for exemption dated October 2, 1987 is available for public inspection at the Comission's Public Document Room, 1717 H Street, NW, Washington, D.C. and at the Plymouth Public Library, 11 North Street, Plymouth, Massachusetts 02360.
Copies may be obtained upon written request addressed to the U.S. Nuclear Regulatey Comission, Washington, D.C.
20555, Attention:
Director, Division of Reactor Projects I/II.
i This Exemption is effective upon issuance.
DatedatRockville, Maryland,this[
day of
[ N FOR THE NUCLEAR REGULATORY COPMISSION Bruce A. Boger, Acting Director Division of Reactor Projects I/II Office of Nuclear Reactor Regulation l
i EXEMPTION - PILGRIM NUCLEAR POWER STATION DISTRIRtlTIONj, Docket File <
NRC & Local PDRs PDI-3 Reading TMurley/1Sniezek FMiraglia CRossi SAVarga BABoger MRushbrook DGMcDonald OGC-WF EJordan JPartlow TBarnhart (4)
ACRS (101 GPA/PA ADM/LFMA Gray File i
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