ML20091L892

Application for Amend to License DPR-50 (Tech Spec Change Request 135),specifying Appropriate Limits of Hydrogen & Oxygen in Waste Gas Holdup Sys for Expected Plant Conditions & Evolutions

ML20091L892
Person / Time
Site:	Three Mile Island
Issue date:	06/01/1984
From:	Hukill H GENERAL PUBLIC UTILITIES CORP.
To:
Shared Package
ML20091L889	List: ML20091L887 ML20091L892 ML20091L899
References
NUDOCS 8406080244
Download: ML20091L892 (4)

Text

T, METROPOLITAN EDISON COMPANY JERSEY CENTRAL POWER & LIGHT COMPANY AND PENNSYLVANIA ELECTRIC COMPANY THREE MILE ISLAND NUCLEAR STATION, UNIT 1 Operating License No. DPR-50 Docket No. 50-289 Technical Specification Change Request No. 135 This Technical Specification Change Request is submitted in support of Licensee's request to change Appendix A to Operating License No.

DPR-50 for Three Mile Island Nuclear Station, Unit 1. As a part of this request', proposed replacement pages for Appendix A are also included.

GPU NUCLEAR CORPORATION

.8406080244 840601 Director, TMI-l PDR ADOCK 05000289 P PDR- l

.Svorn and subscribed U to .before me this jais. .. l dayq f g , 1984

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.y DARLA JEAN BERRY, NOTARY PU6UC N!00LiiOWN BORO. DAUPHIN COUNTY MY COMMIS$10N EXPIRES JUNE 17.1985

. Member, Pennytvama Assocation of Limes F  %..O

UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION IN THE MATTER OF DOCKET No. 50-289 LICENSE NO. DPR-50 GPU NUCLEAR CORPORATION This is to certify that a copy of Technical Specification Change Request No. 135 to Appendix A of the Operating License for Three Mile Island Nuclear Station Unit 1, has, on the date given below, been filed with the U. S. Nuclear Regulatory Commission and been served on the chief executives of Londonderry Township, Dauphin County, Pennsylvania; Dauphin County, Pennsylvania; and the Pennsylvania Department of Environ-mental Resources, Bureau of Radiation Protection, by deposit in the United States mail, addressed as follows:

Mr. Jay H. Kopp, Chairman Mr. John E. Minnich, Chairman Board of Supervisors of Board of County Commissioners Londonderry Townsh'ip of Dauphin County R. D. #1, Ceyers Church Road Dauphin County Courthouse Middletown, PA 17057 Harrisburg, PA 17120 Mr. Thomas Gerusky, Director Penna. Dept. of Environmental Resources Bureau of Radiatioc Protection P.O. Box 2063 Harrisburg, PA 17120 GPU NUCLEAR CORPORATION s

BY Director, TMI-l DATED: June 1,1984

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l TEGNICAL SPECIFICATION GANGE REQUEST No.135 The Licensee requests the attached pages replace 3-101, 3-105, 3-105a, 3-116, and 4-91 of the existing Technical Specifications.

REASON FOR G ANGE REQUEST ,

'Ihis Tech Spec Change Request specifies appropriate limits of hydrogen and oxygen in the Waste Gas Holdup Systcm (WGHS) for expected plant conditions and evolutions. During times of traintenance and inspection, high oxygen levels are expected due to opening the system to atmosplere, with insufficient hydrogen present for flame propagation. (See License Event Reports 82-08, 83-05, 83-08). During other evolutions, such as normal cooldwn degassing, temporary high hydrogen levels are expected with insufficient oxygen present for flame propagation.

SAFETY EVAIDATICN JUSTIFYn1G GANGE NRC IE Information Notice 81-27 states: "Flanmable concentration of gas mixtures can be prevented by limiting either the hydrogen or the oxygen concentration to less than 3 percent". Experimental data

• on the flamability of hydrogen in oxygen provides, under ideal conditions, a A mer limit of 5%

oxygen by volur.e. Therefore, if the concentration of oxygen in a nitrogen /

hydrogen / oxygen gas mixture is kept below a concentration of 5% by volume when-ever the hydrogen concentration is greater than or equal to 5% by volume, any gas mixture within these bounds will be below the flanmability limit. With concentrations procedurally limited to less than or equal to 2% oxygen by volune more than sufficient margin exists to preclude flame propagation regardless of hydrogen concentration. This proposed specification provides that the oxygen concentrations in the waste gas system will be limited to less than or equal to 2% by volume whenever the hydrogen concentration is greater than 4%

by volune.

If the oxygen concentration in the waste gas system ever exceeds 2% by voluan when the hydrogen concentration is greater than or equal to 4% by volume, the oxygen concentration will be rhd without delay to below 2% by volume. In addition, if the oxygen concentration in the waste gas system ever exceeds 4%

by volume when the hydrogen cnnoentration is greater than or equal to 4% by volume, the addition of waste gas to the waste gas system will be unediately suspended and the oxygen concentration will be reduced without delay to below 2% by volume. These 2% oxygen and 4% hydrogen limits provide a conservative

~

, margin of safety in view of the 5% oxygen and 5% hydrogen ideal flaninability i

limits.

As specified in Standard Review Plan (SRP) 11.3, Rev. 2 -July,.1981, (Page 11.

3-5) of NUREG-0800,for systems designed to operate belcw set limits for both hydrogen and oxygen may be analyzed for either hydrogen or oxygen. This

. Tech Spec diange by specifying nonitoring of both, oxygen and hydrogen is providing a second cnnservative margin of safety. In addition, flanmability limits are specified for ideal conditions of hydrogen and oxygen only. The potential for adverse concentrations of hydrogen and oxygen in the WG System is very low because a nitrogen overpressure is maintained on the system.

,*Bulletin 503, Bureau of Mines; Limits-of Flantrability of Gases and Vapors.

i Based on the factor of 20 tilnes the operating absolute pressure criteria given in NUREG 0800 SRP 11.3, Part II.B.6.a, the major a:xaponents in the WGHS are capable of withstanding the 330 psig explosion pressure pulse (16.5 psia x 20 = 330 psigl Since the specification regiires dual gas analysers (1 hydrogen,1 oxygen) provide continuous independent neasurements verifying hydrogen or oxygen is not present in potentially explosive concentrations, SRP 11.3 Part II.B.6 guidelines are exceeded. The explosion resistance capability of the major cxxnponents of the WGHS thus supports the Standard Technical Specifications guideline for one(1) channel operation. The proposed specification provides that a single monitor be required operable for each variable, thus providing independent nonitoring. The system loop seals and compressors operation insure adequate provisions to minimize leakage after a postulated explosion.

Prevention of a cmbustible mixture is necessary to prevent an event that would release significant quantity and concentration of radioactive material.

Waste Gas Tank Rupture has been previously analyzed in INI-l FSAR Update Section 14.2.2.6.

With the limits as stated in the specification, adequate protection is afforded against hydrogen-oxygen cx2nbustion and assurance is provided that the release of radioactive materials will be suitably controlled in confornance with General Design Criteria 60 of Appendix A to 10 CFR Part 50.

SIGNIFICANT HAZARDS OCNSIDERATICN EVALIATION The proposed specification is provided to ensure that the concentrations of potentially cmbustible gas mixture contained in the waste gas holdup system is maintained below flamability limits. This can be achieved by limiting concentrations of either hydrogen or oxygen below their lower limits of flanmability. The conditicms of specification 3.22.2.5 limits hydrogen and oxygen with sufficient margin to preclude flame propagation. Specification 3.22.2.5 provides a margin of 3% oxygen concentration outside the flamability limits. Therefore, operaticn of iMI-l in accordance with this Tech. Spec.

Change Request does not:

a) . increase the probability of occurrence or the consequences of accidents previously analyzed as the Waste Gas Tank Rupture (FSAR Update Section 14.2.2.6).

b) create the possibility for an accident or malfunction of a new or different kind of accident frcm any accident previously evaluated.

c) involve a significant reduction in the margin of safety since adopted limits of H and O concentrations are conservative. Therefore, 2

significant safety azards are not associated with this change.

AMENEMENT CLASSIFICATICN (10 CFR 170)

This change request involves the review of a single safety issue and is considered a Class III Amendment. A check for $4,000.00 is enclosed with this stixnittal.

IMPLEMENTATICN It is requested that this Amendnent becme effective upon issuance.

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