ML19319D954
| ML19319D954 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 10/20/1976 |
| From: | SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | |
| Shared Package | |
| ML19319D934 | List: |
| References | |
| NUDOCS 8003270630 | |
| Download: ML19319D954 (3) | |
Text
{{#Wiki_filter:T 4 Y RANCHO SECO UNIT I t<-) TECHNICAL SPECIFICATIONS Limiting Conditions for Operation 39 SECONDARY WATER CHEM!STRY Applicability Applies to the secondarf water chemistry when the reactor is greater than 15% power. Obj ec t i ve To maintain the cation conductivity of the steam generator fecdwater at or less than 0.5 pmhos/cm. Specification 3.9.1 If the cation conductivity of the steam generator inlet exceeds 0.5 pmhos/cm but is less than 1 pmhos/cm, restore the cation conductivity below this limit within 72 hours or be in at least hot shutdown within the next 12 hours. 3.9.2 If the cation conductivity of the steam generator inlet exceeds 1.0 pmhos/cm but is less than 2.0 pmhos/cn, restore the cation conductivity below this limit within 24 hours. After restoration, Specification 3.9.1 shall apply. If the cation conductivity is not reduced to less than 1.0 pmhos/cm bring the reactor to hot shutdown within the next 12 hours. 393 If the cation conductivity of the steam generator inlet exceeds 2.0 pmhos/cm, restore the cation conductivity below this limit within 12 hours. After restoration, Specification 3 9.2 shall apply. If the cation conductivity is not reduced to less than 2.0 pmhos/cm bring the reactor to hot shutdown within the next 12 hours. Bases 4 The limitations on secondary feedwater cation conductivity minimizes the degradation of the steam generator tubes and the potential for steam generator tube leakage or failure due to stress corrosion. Contamination of the steam generator secondary coolant increases the potential of tube degradation and the impairment of tube integrity. Generally, the most severe contamination results from condenser inleakage of impuritics that may enter the secondary side of the stean generators if breakthrough of the condensate polishing demineralizers occurs. Continuous monitoring of the secondary feedwater by cation conductivity is an effective means of monitoring condensate polishing demineralizer breakthrough and mini-mizing the introduction of contaminants to the steam generator. During operations, the most common contaminants found in the demineralizer effluents will be at concentrations sufficiently low to be soluble in the superheated steam and will not accumulate or cor.centrate ingh steam generators. 8003~ Maintaining the secondary feedwater within the limits of this specification will cont ol the in t roduc t ion of potent ia l ly corros ive in,pur i t ' as into the steam generators and minimize tube degradat ion. This monitoring provides reasonable assurance that the conditions in the steam generators minimize the potential fcr tube degradat ion during ali conditions of operat ion and l postulated accidents, as a measure of protection of the steam generator tubing Which is an essential part of the reactor coolant pressure boundary.
RANCHO SECO UtilT I TECHfflCAL SPECIFICATI0lis Limiting Conditions for Operation Bases -(continued) During initial plant startup, small air inleakage may occur in the condensate and feedwater system. Carbon dioxide ingress through these leaks elevates the feedwater cation conductivity, but is not detrimental to plant materials 45 for the relatively short initial startup period up to 70% power. Degassing of the feeduater sample to eliminate the carbon dioxide will result in a cation conductivity measurement which is indicative of only the corrosive contaminants and will not result in unwarranted corrective action or shutdowns during the startup period. i Proposed Amendment flo. 45 1 m_ __
A ..E-RANCil0 SECO Util r.1, ,.i gj TECHNICAL SPECIFICATIO!!S ' Surveillance Standards TABLE 4.1-3 -Ml!11 MUM SAMPLillG FREQUENCY [ ~ lten Check Frequency 1 1. Reactor-coolant a. Radio-chemical a ,is(1) M i E determinotio Semiannual 1y l .b. Gross activity 1) (3) 3/ week -c.- Tritium radioactivity .M d. Chemistry (Cl and 02) 3/ week c. Boron concentration ~ 2/ week l 2. Dorated water storage. Boron concentration M and af ter each makeup tank water sample g) 3 Core flooding. tank . Boron' concentration M and af ter each i water sampic makeup 4. Spent fuel storage Boron concentration-M and after each water sample makeup g) 5 Secondary coolant a. Gross activity Weekly b. lodine analysis (2) (3) Weekly l c '. Cation Conductivity (3) Daily (6) 45 6. Concentrated boric Boron concentration 2/ week and after- + I acid tank each makeup 7 Vaste gas decay Isotope analysis Q, Prior to tanl: release j 8. Auxiliary Building isotope analysis W plant vent 9. Spray additive tani: NaOH concentration (3) Q and after each makeup 4-10. Purge vent Gross activity During each ] Purge 11. Blowdown from cooling Gross activity (3) M l 1 (1) When radioactivity leve'l is greater than 20 percent of the limits of 1-
- Technical Specification 3.1.4, the sampling frequency shall be increased
. to 'a minimum of once each day. When gross activity increases by a factor of two above normal, an 1 iodine analysis will be made and performed _thereafter when the gross i activity increases by-ten percent. (3) Not performed during cold shutdown. (4) When activity-level exceeds ten percent of the 1imits of 10 CFR 20, the i sampling frequency ~shall be' increased to'a minimum of once each day. (5) E determination will'bc started when gross beta gamma activity. analysis indicates greater than 10 uci/ml and;will be redetermined each.10 pCi/mi ~ increase in gross beta gamma activity analysis. A radio chemical analysis- !~ . for this purpose-shall consist of;a quantitative measurement of -953 of. E
- radionuclidesf in reactor coolant with half lives 'of >30. minutes.
(6) Grab samples daily when the continuous monitor is out of wrvice. l45 Proposed Amendment No. 45 -.4 9 -- - - =}}