ML20244D384

Proposed Tech Specs Re Steam Generator Pressure/Temp Limits, Primary Pump Seal Water Sys,Control Room Emergency Air Cleaning Sys & Sealed Source Contamination

ML20244D384
Person / Time
Site:	Yankee Rowe
Issue date:	04/14/1989
From:	YANKEE ATOMIC ELECTRIC CO.
To:
Shared Package
ML20244D381	List: ML20244D380 ML20244D384
References
NUDOCS 8904210316
Download: ML20244D384 (6)

Text

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. Pl. ANT SYSTEMS BASES 3/4.7.2 STEAM GENERATOR PRESSURE / TEMPERATURE LIMITATION The limitation on steam generator pressure and temperature ensures that the pressure induced stresses in the steam generators do not exceed the maximum allowable fracture toughness stress limits. The limitations are based on a steam generator initial RT NDT lP us 600F and are sufficient to prevent brittle fracture.

3/4.7.3 PRIMARY PUMP SEAL WATER SYSTEM (Deleted) 3/4.7.4 SERVICE WATER SYSTEM (Deleted) 3/4.7.5 CONTROL ROOM EMERGENCY AIR CLEANING SYSTEM The operability of the Control Room Emergency Air Cleaning System ensures that occupancy of the Control Room under design basis accident conditions will not result in Control Room personnel receiving radiation exposures in excess of 5 rem whole body, or its equivalent to any part of the body, for the duration of the accident (GDC 19, 10CFR50).

3/4.7.6 SEALED SOURCE CONTAMINATION The limitation on removable contamination for sources requiring leak testing, including alpha emitters, is based on 10CFR70.39(c) limits for plutonium. This limitation will ensure that leakage from byproduct, source, and special nuclear material sources will not exceed allowable intake values.

Sealed sources are classified into three groups according to their use, with surveillance requirements commensurate with the probability of damage to a source in that group. Those sources which are frequently handled are required to be tested more often than those which are not. Sealed sources which are continuously enclosed within a shielded mechanism (i.e., sealed sources within radiation monitoring or boron measuring devices) are considered to be stored and need not be tested unless they are removed from the shielded mechanism.

YANKEE-ROWE B 3/4 7-4 Amendment No. 52, 83, 8904210316 890414 PDR ADOCK 05000029 P PDC

'. PLANT SYSTEMS l 3/4.7.5 CONTROL ROOM EMERGENCY AIR CLEANING LIMITING CONDITION FOR OPERATION 3.7.5 The Control Room Emergency Air Cleaning System shall be OPERABLE.

APPLICABILITY Modes 1, 2, 3, and 4 ACTION

a. With the Control Room Emergency Air Cleaning System inoperable, except as a result of one inoperable fan and motor set, restore the system to OPERABLE status within 3-1/2 days or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

b. With one inoperable fan and motor set, restore the inoperable fan and motor set to OPERABLE status within 7 days or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

SURVEILLANCE REQUIREMENTS 4.7.5.1 At least once per 31 days:

a. Initiate from the Control Room and maintain for at least 15 minutes, for each fan and motor set, Control Room Emergency Air Cleaning System flow through the HEPA filter and charcoal absorber.

b. Manually shut down the Control Room unit ventilator, UV-2, from the Control Room and verify closure of the Control Room Emergency Air Cleaning System Isolation Dampers A and B.

4.7.5.2 At least once per 18 months, manually close Control Room Fire Dampers B and E from the Control Room.

4.7.5.3 At least every 18 months and following painting, fire, or chemical release in any ventilation zone communicating with the system, while the system is operating, that could contaminate and impair the function of the HEPA filters or charcoal adsorbers, the Filter System shall be demonstrated OPERABLE by verifying that:

a. The results of the in-place cold D0P and halogenated hydrocarbon tests at design flows on HEPA and charcoal filter banks shall show 199% DOP removal and 199% halogenated hydrocarbon removal.

b. Within 31 days after removal that the results of laboratory carbon sample analysis performed at representative system flow rates shall show 199% radioactive methyl iodine removal.

YANKEE-ROWE 3/4 7-18 Amendment Number

PLANT SYSIEMS SURVEILLANCE REOUIREMENJS (continued)

c. Recirculation Filter System flow rate is 3,000 cfm i10% during system operation.

d. The pressure drop across the combined prefilter and HEPA filter bank is 14 inches H2O while operating at the system flows specified above.

4.7.5.4 Fal10 wing maintenance or replacement activities, only those components which may have been adversely affected by the activity need be tested. Specifically:

a. Cold D0P testing shall be performed after each complete or partial replacement of the HEPA filter bank,

b. Halogenated hydrocarbon testing shall be performed after each complete or partial replacement of the charcoal filter bank.

c. DOP and halogenated hydrocarbon test shall be performed following any significant modification to the filter housing that could have an adverse effect on the filter efficiency.

d. An air distribution test demonstrating uniformity within 120%

across the HEPA filters and charcoal adsorbers shall be performed if the filter housing is modified such that air distribution could be adversely affected.

4.7.5.5 The sample analysis of Specification 4.7.5.3.b shall be performed after every 720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> of system operation.

YANKEE-ROWE 3/4 7-18a Amendment Number

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Yankee Atomic Electric Company Proposed Change No. 209 ATTACHMENT A BACKGROUND Submitted as part of Reference (b), the proposed Technical Specification change for the Yankee Control Room Emergency Air Cleanup System (CREACS) was rejected by the USNRC in Reference (c). Reference (c) states, "The request reflected operation that was susceptible to single failure and needed to be re-evaluated by the licensee." The following discussion provides our re-evaluation.

DISCUSSION CREACS Re-Evaluation for Single Failure Susceptibility In submitting the CREACS single filter train conceptual design to the USNRC, References (d) and (e), additional provisions were provided to ensure the reliability of the Filter System. These provisions provided for both a quick filter change out capability as well as having on hand an entire filter media reload. Given these additional protisions, the USNRC found the design of Yankee's CREACS to be acceptable, heference (f). The side loading rack design of Yankee's as-built filter train does provide for quick change out of all filter media, particularly the carbon media trays which are used rather than bulk carbon loading. Yankee also maintains in stock one entire reload of certified carbon media trays, carbon test cells, and HEPA filters and prefilters.

However, in submitting the proposed CREACS Technical Specification, Reference (b), the letter could be interpreted to allow the inoperability of the CREACS filter train during normal operation. That is, under the limiting conditions for operation it is stated, "With the passive train (filter unit) of the Control Room Emergency Air Cleaning System inoperable, restore to OPERABLE status within 3-1/2 days or be in at least HOT STANDBY within the next six hours and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />." The implied inoperability requires clarification.

The proposed surveillance requirements require that each refueling the filter train be testad to show greater than or equal to 99% DOP removal, greater than or equal to 99% halogenated hydrocarbon removal, and greater than or equal to 99% radioactive methyl iodine removal. Assuming a normal six-week refueling for Yankee, it is possible to remove a carbon test cell early on in the refaeling, and within 31 days perform the laboratory analysis to determine the rac.oactive methyl iodine removal efficiency of the carbon trays. Following acceptance or replacement of the carbon trays, the DOP and hydrocarbon removal efficiency tests would be performed along with system flow and filter

Yankee Atomic Electric Company Proposed Change No. 209 ATTACHMENT A (Continued) differential pressure measurements. This would result in a fully tested. I fully operable filter prior to the end of the refueling. While this is the desired sequence of events, Yankee recognized the difficulties associated with scheduling the carbon test cell removal at the beginning of each refueling.

During the 1987 Yankee refueling, significant Main Control Board (MCB) rework was performed which required the MCB to be repainted. Accordingly, the carbon test cell was not removed until this painting was complete so as to ensure that the' paint fumes did not degrade the carbon filter media. The carbon test cell was removed, and with the exception of the carbon test cell laboratory analysis, all testing was successfully performed during the last week of the refueling. The results of the carbon test cell analysis, which were received after the -ant returned to normal operation, showed the methyl iodine removal efficiens, to be 99.4%. The filter train was, therefore, still deemed operable.

Had the laboratory analysis for methyl iodine removal efficiency shown less than 99% efficiency, the filter train would have been declared inoperable and the action statement of the proposed Technical Specification would have applied. This does not constitute susceptibility to a single failure for the following reasons:

1. Carbon filters do not degrade catastrophically.. Rather, they exhibit gradual degradations in their efficiency. At Yankee this degradation has been less than 0.2% per refueling interval. A passive filter train is not analogous to active components such as motors or switches which are assumed to either function or not function. The filter train, even though inoperable by definition (less than 99% methyl iodine removal efficiency), would still be a functional component.

2. Even assuming a degradation of twice the current rate of 0.2% per refueling interval and assuming the worst case, the carbon had tested satisfactorily the previous refueling at the proposed Technical Specification limit of 99.0% methyl iodine removal efficiency, a minimum efficiency of 98.6% would exist. This continues to exceed the assigned activated charcoal decontamination efficiency of 95% and, thus, maintains the conservatism of the Control Room personnel radiation exposure analysis.

3. Yankee maintains a certified carbon reload in stock. The carbon tray desigr. allows for replacement in less than one hour and would be performed as soon as test personnel who can perform DOP bypass leakage testing are on-site. Replacement would not be performed immediately due

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Yankee Atomic Electric Company Proposed Change No. 209 ATTACHMENT A i (Continued) to the possibility of creating a bypass leakage path. Continuing to operate with the assumed 98.6% efficient carbon media would maintain the conservatism of the Control Room exposure analysis. Changing out the carbon media without the abil# ty to verify bypass leakage could, on the other hand, significantly affect the Control Room exposure analysis.

Therefore, 3-1/2 days were provided for in the proposed change in order to allow for securing the services of testing personnel who would test j for bypass leakage immediately after the carbon tray replacement.

The proposed change to the Yankee Technical Specification for the CREACS provides for reasonable flexibility in scheduling filter efficiency testing. It does so while also maintaining the conservatism of the Control Room personnel radiation exposure analysis. It was not Yankee's intention to infer continued full power operation without the availability of the CREACS filter train, but within the limited context of OPERABLE versus INOPERABLE that implication did result. With the proposed Technical Specification surveillance requirements, the filter train is declared INOPERABLE, and replaced while it can still perform its intended function; i.e., it is still a system capable of operating. It is being. replaced in the time frame specified due to the conservatism built into the surveillance acceptance criteria. With the above clarification, Yankee continues to support the proposed change to the Technical Specification.

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