ML20217G773
| ML20217G773 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 10/03/1997 |
| From: | Stone J NRC (Affiliation Not Assigned) |
| To: | Maynard O WOLF CREEK NUCLEAR OPERATING CORP. |
| References | |
| TAC-M99633, NUDOCS 9710140208 | |
| Download: ML20217G773 (3) | |
Text
~.
T October - 3, 1997 l
LMr. Otto L. Maynard President and Chief Executive Officer.
Wolf Creek Nuclear Operating Corporation Post Office Box '411 Burlington.> Kansas 66839-
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SUBJECT:
WOLF CREEK GENERATING STATION - TECHNICAL SPECIFICATION BASES CHANGE. SOURCE RANGE NUCLEAR INSTRUMENTS POWER SUPPLY REQUIREMENTS (TAC NO. M99633)'
Dear Mr. tiaynard:
The staff has incorporated the revision of the Bases for Technical Specification 3/4 9.2:" Refueling Operations -- Instrumentation" as provided by your letter dated September 19. 1997.. into the Wolf Creek Generating Station -
Technical S)ecifications. The revisich specifies the acceptable-sources of-aower for tle source range nuclear instruments when the plant is in Mode 6.
lefueling.
(
In your letter of September 19. 1997. you discuss the use of the G6mma-Metrics j
system as a backup if the temporary power is lost _to one train of normal source range indication.
The staff understands that the Gamma-Metrics system will not be used as a backup if one train of normal source range indication is loste The discussion was included to show the diversity of indication available at Wolf Creek. -The staff also understands that if one of the normal source range instruments is declared inoperable, the appropriate action statement of TS 3.9.2 will be followed.
The staff has reviewed the change and finds the revision to the Bases to be acceptable. The overleaf page is provided to maintain document completeness.
Sincerely.
Original Signed By-Jrmes C. Stone. Senior Project Manager Project-Directorate IV-2 Division of Reactor Projects III/IV Office of Nuclear Reactor Regulation-Docket No. 50-482 11STRIBUTION:
Docket File-JStone f
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$Y Hr. Otto L.- Maynard October 3, 1997
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Jay Silberg...Esq.
Chief' Operating Officer Shaw, Pittman, Potts-& Trowbridge Wolf 0. reek Nuclear Operating Corporation 2300 N Street, NW P. 0. Box 411 Washington, D.C, 20037 Burlington, Kansas 66839 Regional Administrator. Region IV Supervisor Licensing U.S. Nuclear Regulatory Commission Wolf Creek Nuclear Operating Corporation 611 Ryan Plaza Drive. Suite 1000 P.O. Box 411 Arlington, Texas 76011 Burlington, Kansas 66839 Senior Resident Inspector U.S. Nuclear Regulatory Commission U.S. Nuclear Regulatory Commission Resident Inspectors Office P. O. Box 311 8201 NRC Road Bur.lington, Kansas 66839 Steedman, Missouri 65077-1032 Chief Engineer Utilities Division Kansas Corporation Commission 1500 SW Arrowhead Road.
Topeka. Kansas 66604-4027 Office of the Governor State of Kansas Topeka, Kansas 66612 Attorney General Judicial Center 301 S.W. 10th i
2nd Floor Topeka, Kansas 66612
,' County Clerk.
TCoffey County Courthouse Burlington, Kansas 66839-
.Vick L. Cooper, Chief Radiation Control Program Kansas Department of Health and Environment Bureau of-Air and Radiation
~Forbes Field Building 283 Topeka.-Kansas 66620
O 3
3/t9 REFUELING OPERATIONS L
I BASES 3/4 9.1 BORON CONCENTRATION The limitations on reactivity conditions during REFUELING ensure that:
(1) the reactor will remain subcritical during CORE ALTERATIONS, and (2) a uniform boron concentration is maintained for reactivity control in the water volume having direct access to the reactor vessel.
The limitation on Keff of no greater than 0.95 is sufficient to prevent reactor criticality during refueling operations.
The locking closed of the required valves during refueling operationc precludes the possibility of uncontrolled boron dilution of the filled portions of the Reactor Coolant System.
This action prevents flow to the RCS of unborated water by closing flow paths from sources of unborated water.
These limitations are consistent with the initial conditions assumed for the boron dilution incident in the safety analyses.
3/4.9.2 INSTRUMENTATION The OPERABILITY of the Source Range Neutron Flux Monitors ensures that redundant monitoring capability is available to detect changes in the reactivity condition of the core.
When any of the safety-related busses supplying power to one of the detectors (SE-NI-31 or 32) associated with the Source Range Neu an Flux Monitors are taken out of service, the corresponding Source Range Flux Monitor may be considered OPERABLE when its detector is powered from a temporary non-safety related source of power, provided the detector for the opposite Source Range' Neutron Flux Monitor is powered from its normal power source.
When determining compliance with action statement requirements, addition to the RCS of borated water with a concentration greater than or equal to the minimum required RWST concentration shall not be considered to be a positive reactivity change.
3/4.9.3 DECAY TIME The minimum requirement for reactor subcriticality prior to movement of irradiated fuel assemblies in the reactor vessel ensures that sufficient time has elapsed to allow the radioactive decay of the short-lived fission products.
This decay time is consistent with the assumptions used in the safety analyses.
3/4 9.4 CONTAINMENT BUILDING PENETRATIONS The requirements on containment building penetration closure and OPERABILITY ensure that a release of radioactive material from containment will be minimized. The OPERABILITY and closure restrictions are sufficient to restrict radioactive material release from a fuel element rupture based upon the lack of containment pressurization potential while in the REFUELING MODE.
The OPERABILITY of this system ensures the containment purge penetrations will be automatically isolated upon detection of high radiation levels within containment.
The OPERABILITY of this system is required to restrict the release of radioactive materials from the containment atmosphere to the environment.
WOLF CREEK - UNIT 1 B 3/4 9-1 Amendment No. 74.95 October 3, 1997
1
...e REFUELING OPERATIONS t'
1 M1ES g
3/4;9.4' CONTAINMENT BUILDING' PENETRATIONS (Continued)
Both containment personnel airlock doors may be open during movement of irradiated fuel or CORE ALTERATIONS, provided one airlock door is capable of i
being closed and the water level in the refueling pool is maintained as l-required. Service Air valves KA V-039 and KA V-118 (Containment penetration j
P-63) and Breathing Air valves KB V-001 and KB V-002 (Containment penetration P-98) may be opened under administrative controls during movement of irradiated fuel-or CORE ALTERATIONS to provide air servicas to the reactor 1
j building to support outage activities.
Administrative controls ensure that 1) 4 appropriate personnel are aware of the open status of the containment during movement of irrad;ned fuel or CORE ALTERATIONS,- 2) specified individuals are designated and readily available to close-the airlock or the service air and I
breathing air valves following an evacuation that would occur in the event of l
a fuel handling accident, and 3) any_ obstructions (e.g., cables and hoses) that-could prevent rapid closure of an open airlock can be quickly removed.
Equivalent isolation methods for the emergency personnel escape lock and containment wall penetrations ensure releases from containment are prevented for credible accident scenarios.
The isolation techniques must be approved by an engineering evaluation and may include use of a material that can provide a temporary, pressure tight seal capable of maintaining the integrity of the penetrations and airlock to restrict the release of radioactive material from a fuel element rupture.
3/4.9.5 DELETED _
_ [
3/4.9.6 DELETED 3/4.9.7 DELETED 3/4.9.8 RESIDUAL HEAT REMOVAL AND COOLANT CIRCULATION The requirement that at least one residual heat removal (RHR) loop be in
, operation ensures that: (1) sufficient cooling capacity is available to remove decay heat and maintain the water in the reactor vessel below 140'F as required during-the REFUELING MODE, and (2) sufficient coolant circulation is maintained through the core to minimize the effect of a boron dilution incident and prevent boron stratification.
The minimum of 1000 gpm allows flow rates which provide additional margin against vortexing at the RHR pump suction while in a reduced RCS inventory condition.
Addition of-borated water with a concentration greater than or equal to the minimum required RWST concentration but less than the actual RCS boron concentration shall not be considered a reduction in boron concentration.-
The requirement to have two RHR loops OPERABLE when there is less than 23 feet of. water above the reactor vessel-flange ensures that a single failure of the operating RHP. loop will not result in a complete loss of RHR capability. With the reactor vessel head removed and at least 23 feet of water above the reactor vessel flange, a large heat sink is available for core I
cooling. Thus, in the event of a failure-of the operating RHR loop, adequate time is provided to initiate emergency procedures to cool the core.
WOLF CREEK - UNIT 1 B 3/4 9-2 Amendment No. 25,00,05,107
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