ML20063E607
| ML20063E607 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 01/27/1994 |
| From: | Rehn D DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20063E608 | List: |
| References | |
| NUDOCS 9402100133 | |
| Download: ML20063E607 (12) | |
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York. SC29745 (bD3)M13426 Fax i
DUKEPOWER January 27,1994 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555
Subject:
Catawba Nuclear Station Docket Nos. 50-413 and 50-414 Proposed Technical Specifications Changes (TS 4.6.3.2.d and 4.9.4.1)
Containment Purge System Humidity Control Function Gentlemen:
Pursuant to 10CFR50.4 and 10CFR50.90, attached are license amendment requests to Appendix A, Technical Specifications, of Facility Operating Licenses NPF-35 and NPF-52 for Duke Power Company's Catawba Nuclear Station Units 1 and 2, respectively. - The requested amendments delete the verification that each upper and lower C tainment Purge System (VP) supply and exhaust valve actuates to its isolation position on a High Relative Humidity (>70%) isolation test signal and will allow elimination of the humidity control function of the VP System humidistats. " Qualified" humidistats are no longer available from the original or any other manufacturer. It has been determined that this request is a cost beneficial licensing action, in that it would be cost prohibitive to requalify other humidistats ($84,000 - 100,000 to qualify an order of 8 new humidistats). Currently, there is no available Duke Power Company inventory of qualified humidistats.
As such, we are requesting that the NRC review this request.
expeditiously.
Attachment I contains a background and description of the enclosed amendment request. describes the changes'to the Technical Specifications and the technicaljustification.
Pursuant to 10CFR50.91, Attachment 3 provides the analysis performed in accordance with the standards contained in 10CFR50.92 which concludes that the requested amendments'do not involve a significant hazards consideration. Attachment 3 also contains an environmentalimpact analysis for the requested amendments. contains the marked-up Technical Specification amendment pages for Catawba. Duke Power Company is forwarding a copy of this' amendment request package to the appropriate South Carolina state official.
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U.S. Nuclear Regulatory Commission Page 2 January 27,1994 l
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. Contingent upon approval, Duke Power Company plans to implement a modification involving VP System control wiring changes that remove the humidistats from the VP System control circuits prior to the Unit 1 End-of-Cycle 8 refueling outage (currently scheduled to begin on February 27,1995) and the Unit ? End of Cycle 7 refueling outage (scheduled to begin on October 11, 1995). The Techhtcal Specifications must be revised to' delete the required VP System humidity control function to permit implementation of this modification. Therefore, it is requested that the NRC review and approval of these prop,ed amendments be completed by September 1,1994, in order that the appropriate procedure and wiring changes can be implemented prior to these outages.
Should there be I,y questio.
Aming this amendment request or should additional information be rgr red, please call J.L. Lowery at (803) 831-3414.
Very truly yours, i
D.L. Rehn i
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Attachments i
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7 U.S. Nuclear Regulatory Commission Page 3 January 27,1994 i
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xc (W/ Attachments): S.D. Ebneter, Regional Administrator RegionII R.J. Freudenberger Senior Resident Inspector R.E. Martin, ONRR
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Heyward Shealy, Chief Bureau of Radiological Health, SC American Nuclear Insurers M&M Nuclear Consultants INPO Records Center t
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U.S. Nuclear Regulatory Commission Page 4 January 27,1994 i
D.L. Rehn, being duly sworn, states that he is Vice-President of Duke Power Company; that j
he is authorized on the part of said Company to sign and file with the Nuclear Regulatory Commission this revision to the Catawba Nuclear Station License Nos. NPF-35 and NPF-52 and that all statements and matters set forth therein are true and correct to the best of his knowledge.
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D.L. Rehn, Site Vice-President Catawba Nuclear Station Subscribed and sworn to before me this 27th day of January,1994.
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y ATTACIIMENT 1 BAC.KGROUND AND DESCRIPTION OF REQUEST h
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o BACKGROUND The Containment Purge (VP) System is designed to maintain the environment of the containment l
within acceptable limits for personnel during inspection, testing, maintenance and refueling operations and to limit release of any contamination to the environment. This system does not operate and is tagged-out, with power removed and containment isolation valves closed, during plant modes 1, 2, 3 or 4. The VP system is non-safety related except for the containment -
isolation valves and the humidistats used to terminate system operation on high relative humidity entering the carbon filter trains. This system is available for operation during Modes 5,6, and No Mode (fuel removed from core). The VP System design basis accident is defined as a fuel handling accident inside. containment.
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Technical Specification (TS) changes #90 (U1) and #84 (U2) revised the carbon testing requirements to 95 % RH equilibrium conditions allowing the carbon bed adsorber to experience
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higher relative humidity levels and still remain within analyzed conditions. The heaters were also recognized in the TS changes as not being necessary for immediate operability concerns. The humidistats are still in place serving their criginal control function.
Prior to TS changes #90 (U1) and #84 (U2) the VP System carbon bed adsorbers were tested j
I at 70% RH. Non-safety related electric duct heaters located up stream of the filter trains raise the temperature of the air from the containment to limit the relative humidity of the air stream i
entering the carbon bed adsorber to <70% RH. Two safety-related humidistats (trains A & B) are located in the duct between the electric duct heater and the filter train. If either humidistat senses a relative humidity equal to or greater than 70% RH, indicating heater failure, the operation of the VP System is terminated and the respective containment isolation valves (train A or B) receive an isolation signal.
t DESCRWTION OF AMENDMENT REOUEST l
This' TS amendment addresses the humidity control function of the humidistats associated with j
the VP System. This proposed TS change will remove the control function of the humidistats.
The termination of the purge function and isolation of the containment on a Containment High Radiation signal will not be impacted by this requested change.
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L ATTACIIMENT 2 CIIANGES TO TECIINICAL SPECIFICATIONS AND TECIINICAL JUSTIFICATION h
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J Cll ANGES TO TECHNICAL SPECIFICATIONS This requested TS amendment deletes the verification that each upper and lower containment purge supply and exhaust valve actuates to its isolation position on a High Relative Humidity
(> 70%) isolation test signal. The TS Surveillance Requirements (SR) 4.6.3.2.d, 4.9.4.1.a and 4.9.4.1.b are deleted.
TECHNICAL JUSTIFICATION The original basis for the humidistats was to ensure that the VP System filter trains operated within their TS limits, i.e., air entering the filter train carbon adsorber was <70% RH. The control function of the humidistats was to terminate VP System operation if the air entering the carbon adsorber was >70% RH, indicating a possible heater failure. The revised carbon surveillance requirements and heater action statement per TS changes #90 (Ul) and #84 (U2) have effectively precluded the control function served by the humidistats.
The activated carbon samples taken from the VP System filter train carbon bed adsorbers are tened at 30*C and 95% RH per ASTM-D3803-89 as required by TS Surveillance Requirement 4.9 2.b.2. This test method was established by TS changes #90 (Ul) and #84 (U2) and is I-L conservative with respect to the plant conditions expected during a fuel handling accident in containment. The carbon to be tested is pre-conditioned for eighteen (18) hours at 95% RH before the methyl iodide challenge (feed) period. The 95% RH value is higher than what would be expected during a design basis event. Postulated accident conditions do not subject the carbon l
to saturated conditions, therefore, the radioactive iodide penetration during a fuel handling accident inside containment will be lower than that predicted by the laboratory test.
Since the Design Basis decontamination efficiencies can be met for the VP System using a test that assumes no heaters, TS changes #90 (U1) and #84 (U2) revised the action statements to indicate that system operability no longer depends on heater operability. An action statement was added to restore an inoperable heater within seven (7) days or file a Special Report within thirty (30) days specifying the reason for inoperability and planned actions to return to operable status.
No change was made in the heater TS surveillance requirements. Even though the heaters remain in service, no credit is taken for them. This results in additional margin.
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ATTACIIMENT 3 NO SIGNIFICANT IIAZARDS CONSIDERATION DETERMINATION AND ENVIRONMENTAL IMPACT ANALYSIS 5
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NO SIGNIFICANT IIAZARDS CONSIDERATION DETERMINATION As required by 10CFR50.91, this analysis is provided concerning whether the requested TS amendments involves significant hazards considerations, as defined by 10CFR50.92. The standard for determining that a Technical Specification amendment request involves no significant hazards considerations requires that operation of the facility in accordance with the requested amendment will not:
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Involve a significant increase in the probability or consequences of an accident previously evaluated; or 2)
Create the possibility of a new or different kind of accident from any accident previously evaluated; or 3)
Involve a significant reduction in the margin of safety.
This requested TS amendment deletes the verification that each upper and lower VP System supply and exhaust valve actuates to its isolation position on a High Relative Humidity (> 70%)
isolation test signal and will allow elimination of the humidity control function of the VP System humidistats.
CRITERION 1 This TS amendment will not increase the probability or consequences of an accident which has been previously evaluated.' No physical changes will be made to the plant that would impact fuel handling inside containment, therefore, there is no increase in the probability of an accident.
Control wiring changes that remove the humidistats from the VP System control circuits will be the only physical change.
The heaters will be maintained providing additional margin over analyzed conditions. For the reasons stated above, there will be no increase in the consequences of an accident previously evaluated.
CRITERION 2 This proposed TS amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated. This proposed TS amendment will not cause any physical changes to the plant that will impact the handling of fuel inside containment or 8.anges to fuel handling procedures Because the plant will operate the same way it does now, this proposed amendment does not create the possibility of any new or different accident from any previously evaluated.
CRITERION 3 This proposed TS change will not cause a significant reduction in the margin of safety. The test method use to evaluate the carbon after TS changes #90(U1) and #84(U2) does not consider
. j heater availability. However the heaters will be tested and maintained per Technical specification 4.9.4.2.d.2. Therefore, the relative humidity of the air entering the carbon adsorber is never expected to reach 95% RH.
ENVIRONMENTAL IMPACT ANALYSIS i
The proposed TS amendment has been reviewed against the criteria of 10CFR51.22 for environmental considerations. As shown above, the proposed change does not involve significant hazards consideration nor increase the types and amounts of effluents that may be released offsite, nor increase individual or cumulative occupational radiation exposure. Based on this, the proposed amendment meets the criteria given in 10CFR51.22(C) (9) for categorical exclusion from the requirements for an Environmental Impact Statement.
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L ATTACIIMENT 4 PROPOSED TECIINICAL SPECIFICATION AMENDMENTS l
FOR CATAWBA NUCLEAR STATION l
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