ML19257A290
| ML19257A290 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 12/27/1979 |
| From: | Moore G FLORIDA POWER CORP. |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8001030578 | |
| Download: ML19257A290 (5) | |
Text
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c.g c,,4 Florida Power C O M PO R A f IO N December 27, 1979 File:
3-0-3-a-3 Mr. Robert W. Reid Chief Operating Reactors Branch #4 U.S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
Crystal River Unit No. 3 Docket No. 50-302 Operating License No. DPR-72
Dear Mr. Reid:
Your letter of October 23, 1979, concerning containment purging and venting during normal operation, requested Florida Power Corporation to commit to operate in conformance with the interim position enclosed in your letter.
T.n that regard, Florida Power Corporation hereby submits our response to your position concerning containment purging and venting.
If you wish to discuss our response further, 1. lease contact us.
Very truly yours, FLORIDA POWER CORPORATION
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6.
. Moore Assistant Vice President fff[ Power Production GCMemhR07(D3) Attachment 8001030 5 ) General Office 3201 inirty-fourth street south. P O Box 14042. St Petersburg, flonda 33733 813-866-5151
a, ( STATE OF FLORIDA COUNTY OF PINELLAS G. C. Moore states that he is the Assistant Vice President, Power Production, of Florida Power Corporation; that he is authorized on the part of said company to sign and file with the Nuclear Regulatory Commission the information attached hereto; and that all such statements made and matters set forth therein are true and correct to the best of his knowledge, information and belief. r r d( y G. C. Moore Subscribed and sworn to before me, a Notary Public in and for the State and County above named, this 27th day of December, 1979. kmu d>ute Notary Public Notary Public, State of Florida at Large, My Commission Expires: August 8, 1983 jff[ } CameronNotary 3(D12)
FPC RESPONSE TO NRC INTERIM POSITION FOR CONTAINMENT PURGE AND VENT VALVE OPERATION POSITION 1: Whenever the containment integrity is required, emphasis should be placed on operating the containment in a passive mode as much as possible and on limiting all purging and venting times to as low as achievable. To justify venting or purging, there must an established need to improve working conditions to perform a safety related surveillance or safety related maintenance procedure. (Examples of improved working conditions would include deinerting, reducing temperature *, humidity *, and airborne activity suf ficiently to permit efficient performance or to significantly reduce occupational radiation exposures). RESPONSE TO POSITION 1: At Crystal River Unit 3, containment entry is required to perform surveillance and maintenance activities during normal operation. Weekly containment entry is required to perform Surveillance Procedure SP-324, Containment Inspection, and monthly entries are required to perform SP-341, Monthly Containment Integrity Check. Those surveillance procedures are performed in accordance with CR #3 Technical Specifications 4. 5.2(b) and 4. 6.1.1, respectively, during operation in Modes 1-4. Also, Preventative Maintenance Procedure PM-104, Inspection and Cleaning of Electric Motors, is conducted on a monthly basis inside containment. In addition to the performance of surveillance and maintenance activities, containment entry is required to repair inoperable safety related equipment. Repair of safety related equipment must be accomplished within the time limitations of the Action Statements contained in the CR #3 Technical Specifications. A typical Action Statement requires repair of the inoperable equipment within 72 hours or the reactor must be in Hot Shutdown within the next 12 hours. If continuous purging is not permftcod at CR #3, entry into the containment to repair this equipment cannot be accomplished within the Action Statement time period. If continuous purging at CR #3 is permitted to continue, these repairs can be accomplished, unnecessary plant shutdowns can be avoided, personnel exposures can be reduced, and the use of respiratory equipment in adverse working conditions can be reduced. As stated in our response to Position 2a below, we have throttled the purge valves partially closed. This has reduced the purge volume f rom 48,000 CFM to 18,000 CFM. If continuous purging is not allowed at CR #3, the purging time required to permit containment entry is increased by a factor of approximately 2.6 and will thereby increase the outage time of the unit. Based on our present leakage and failed GCMemhR07(DN90) 1667 33F
f uel rate, the lower purge rate is sufficient to maintain acceptable airborne activity and temperature levels to pe rm!, containment ent ry at full power. However, it is our intent to seek NRC approval to operate these valves in their 1000 full open position once the valve qualification program by Henry Pratt Co. is completed and submitted to the NRC. Elimination of continuous purging or restricting the purging will result in increased radioactivity in the Containment Building which will increase the dose to personnel working at the plant. This is in contradiction of Florida Power Corporation's ALARA position. It is also the opinion of Florida Power Corporation that due to the buildup of radioactive material in the Containment Building during periods of little or no purging, there is some question as to the soundness of dumping in a batch versus the discharge of small quantities of radioactive material over a year's time. Even with the advantage of decay with holdup, it is uncertain that the dose to the public could be reduced with no or limited purging during operation, requiring purging at higher activity levels during Modes 5 and 6, as compared to continuous low level discharge during all modes of operation. It is our position that continuous purging to maintain radiation and heat factors wnich allow reasonable and acceptable working levels and preclude the use of respiratory and other extensive protection measures to perform surveillance, maintenance, and repair activities, is in the best interest of the safety and welfare of the public and employees of Florida Power Corporation. Based on the above discussion, we believe that adequate need and justification has been presented to allow continuous purging at CR 43. In addition, FPC has taken adequate interim measures, i.e., throttled valves to 65 degrees full open, to insure the operability of these valves during accident conditions. 166733{( GCMemhR07(DN90 )
POSITION 2: Maintain the containment purge and vent isolation valves closed when-ever the reactor is not in the cold shutdown or ref ueling mode until such time as you can show that: a. All isolation valves greater than 3" nominal diameter used for containment purge and venting operations are operable under the most severe design basis accident flow condition loading and can close within the time limit stated in your Technical Specifica-tions, design criteria or operating procedures. The operability of butterfly valves may, on an interim basis, be demonstrated by limiting the valve to be no more thaa 30 degrees to 50 degrees open (90 degrees being f ull open). The maximum opening shall be determined in consultation with the valve supplier. The valve opening must be such that the critical valve parts will not be damaged by DBA-LOCA loads and that the valve will tend to close when the fluid dynamic forces are introduced, and b. Modifications, as necessary, have been made to segregate the con-tainment ventilation isolation signals to ensure that, as a minimum, at least one of the automatic safety injection actuation signals is uninhibited and operable to initiate valve closure when any othec isolation signal may be blocked, reset, o r ove r-ridden. RESPONSE TO POSITION 2: It is the intent of Florida Power Corporation to show by analysis that the 48" purge valves at CR #3 will operate under the design basis accident flow loadings and will close within the time limit stated in our Technical Specifications. We are in the process of obtaining these supporting analyses from the valve manuf acturer, Henry Pratt Co. As stated in our response, dated November 14, 1979, these analyses will be conducted in accordance with the guidelines identified in your le tter, dated September 27, 1979. On an interim basis, we are taking the conservative approach of limit-ing these 48" purge valves to no more than 65 degrees f ull open. This valve setting is based on the written recommendation of the valve manuf acturer, ihnry Pratt Co., to insure closure and it will reduce the aerodynamic torque generated as a result of the design basis LOCA and thereby avoid any structural damage to the valves. We have also reviewed the design of the safety actuation signal cir-cuits at CR 13 to insure that the bypascing of one safety actuation signal does not also cause the bypass of any other safety actuation signal. The CR #3 design also prevents bypassing of an engineered safety feature signal until af ter an actuation of the ESF system has occurred. In addition, there are no individual bypass circuits to operate any of these valves once an engineered safety feature signal has closed the valves. Additional discussion of the ESF bypass design is contained in our January 10, 1979 response. GCMechR07(DN90) 166733(h}}