ML20198J078

Forwards Rev 1 to Plant-Specific Technical Guidelines & Info Re Six Itemized Criteria Concerning Pressure Limit for Emergency Venting of Primary Containment,In Response to Re SER Outstanding Item 14

ML20198J078
Person / Time
Site:	Hope Creek
Issue date:	01/28/1986
From:	Corbin McNeil Public Service Enterprise Group
To:	Adensam E Office of Nuclear Reactor Regulation
Shared Package
ML20198J081	List: ML20198J078 ML20198J084
References
NUDOCS 8601310173
Download: ML20198J078 (7)

Text

Public Service Electric and Gas Company Cctbin A. McNeill, Jr. Public Service Electnc and Gas Company P.O. Box 236, Hancocks Bndge NJ 08038 609 339-4800 Vice President -

Nuocar January 28, 1986 Director of Nuclear Reactor Regulation United States Nuclear Regulatory Commission 7920 Norfolk Avenue Bethesda, Maryland 20814 Attention: Ms. Elinor Adensam, Director Project Directorate 3 Division of BWR Licensing

Dear Ms. Adensam:

PROCEDURES GENERATION PACKAGE PRIMARY CONTAINMENT EMERGENCY VENTING SER OUTSTANDING ITEM #14 IIOPE CREEK GENERATING STATION DOCKET No. 50-354 In response to the letter from Mr. W.R. Butler (Nuclear Regulatory Commission - NRC) to Mr. R.L. Mitti (Public Service Electric and Gas Company - PSE&G) dated November 19, 1985, PSE&G submitted a letter from C.A. McNeill (PSE&G) to E. Adensam (NRC) dated December 30, 1985. Attachment 1 of the response letter indicated that Item 2, the NRC question regarding the primary containment pressure limit, would be addressed in a separate transmittal. This letter addresses the six itemized criteria regarding the pressure limit for emergency venting of the primary containment (Attachment 1). In addition, the Plant-Specific Technical Guidelines (P-STG) are being revised to address the pressure limit as well as other items specified in Attachment 1 and are included as Attachment 2.

Should you have any questions on the subject filing, do not hesitate to call us.

Sincerely, os~ as o,,, tP*

{DR ADUCK oAm,,

05000354 ,1 f $

PDR 1

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Director of Nuclear 2 Reactor Regulation Attachments (3)

C D . fl . Wagner USNRC Licensing Project Manager R.W. Borchardt USNRC Senior Resident Inspector

ATTACHMENT 1 1

I As identified in the NRC letter to PSE&G dated November 19, 1985, Section 2.1 - Plant-Specific Technical Guidelines, I an additional discussion of the primary containment pressure i limit was requested. PSE&G has re-evaluated the need for l emergency venting of the primary containment and its affect on containment integrity in light of the following six ,

items. As a result, PSE&G has decided to establish 65 l psig as the pressure limit at which venting of the primary I containment will begin. The following responses to the l identified NRC concerns justify and support the selection ,

of this primary containment pressure limit.

I

1. Since the use of the identified vent paths in the EOP is an action far beyond design basis events, the applicant should perform a best-estimate evaluation of the vent path valve operability (capability to open and reclose).

Response

As indicated in the response to Item 3 below, sequential vent paths will be utilized if emergency venting is required; however, the limiting components with regard to valve operability are the 24" and 26" butterfly valves. Testing performed on these valves has shown the valves ability to close against LOCA pressure loads and open against 70 psig.

2. A rapid depressurization from venting may result in suppression pool flashing and hydrodynamic loads; the applicant should perform analyses to determine if the resulting hydrodynamic loads exceed the design capability of the suppression pool and submit the results to NRC.

Response

The potential for and effects of rapid depressurization will be minimized by initially using the 2" bypass lines to control pressure (See Item 3, Steps A and C below). The 24" lines (See Item 3, Steps D and E),if opened, will cause hydrodynamic loads not considered in the plant unique analysis; however, our engineering judgement is that the flashing and hydrodynamic loads caused by depressurization will not exceed the loads associated with a large pipe LOCA.

3. The applicant should consider the prioritization of the selected emergency vent paths to minimize radioactive release rates.

2

Response

The following vent paths have been selected to minimize radioactive release rates utilizing the criteria specified in Item 4 below. These paths can be seen on P&ID M-57-1, Containment Atmosphere Control, shown in the FSAR as Figure 6.2-29. The order in which these paths will be used is as listed.

A. The 24" suppression pool exhaust vent via 1-GS-V028 (HV-4964), thru l-GS-V076 (HV-4963) in a 2" bypass line to the FRVS.

B. The 24" suppression pool exhaust vent via 1-GS-V022 (HV-4958), thru l-GS-V067, 1-GS-V023 (HV-4978) and 1-GS-V058 in 6" lines to the 6" leak rate testing line and then via 1-GP-V129 to a blowdown muffler and the atmosphere.

C. The 26" drywell exhaust vent via 1-GS-V024 (HV-4952),

thru l-GS-V025 in a 2" bypass line to the FRVS.

D. The 24" suppression pool exhaust vent via 1-GS-V028, thru l-GS-V027 (HV-4960) in a 24" line to the FRVS.

E. The 24" suppression pool exhaust vent via 1-GS-V022, thru l-GS-V020 (HV-4980) in a 24" line to the contain-ment prepurge cleanup system.

F. The 26" drywell leak rate supply line via 1-GS-V009 (HV-4956), thru l-GS-V023 and 1-GS-V058 in 6" lines to the 6" leak rate testing line and then via 1-GP-V129 to a blowdown muffler and the atmosphere.

G. The 26" drywell exhaust vent via 1-GS-VO24 thru l-GS-VO26 (HV-4950) in a 26" line to the FRVS.

4. The applicant should consider other flow paths, such as the drywell and suppression pool spray headers.

Response

The sequential flow pathE specified in Item 3 above were selected utilizing the following criteria:

A. Begin with smaller line sizes and increase in size to minimize potential releases.

B. Take advantage of the scrubbing effect of the suppression pool water by venting from the suppression pool first.

3 C. Recognizing hydrodynamic loads and failed ductwork may result from selected flow paths, utilize these ,

pathways such that these effects are minimized i and enveloped by existing analyses and qualifications as well as relied upon as final paths were possible.

5. The applicant should consider the effect of containment venting on ductwork failure (if used as a pathway),

and the resulting consequences of subjecting equipment near the failed duct to the steam / radiation environment.

Response

Should ductwork of the primary path chosen (i.e. Item 3, Step A above) fail, failure would be in the torus area where emergency equipment is environmentally qualified for a harsh environment.

The first two 24" paths (i.e. Item 3, Steps D and E) have ductwork in the torus area. If failure occurs it will be in the torus area where the equipment has been environmentally qualified for a harsh environment.

6. The applicant should consider ADS operability at the elevated containment pressure.

Response

In order to maintain ADS operability, a pressure differential of 25 psid must be maintained between'the drywell and the accumulators for the SRV's. Design pressure for the primary containment instrument gas system is 105 psig with the normal operating range of 90-105 psig.

This pressure band is assured by use of two redundant 100% capacity compressors. Therefore, operability of the ADS valves at 65 psig will not be effected.

In support of the 65 psig emergency venting limit for the primary containment, the Plant-Specific Technical Guidelines (P-STG) have been modified accordingly. Attachment 2 of this letter contains Revision 1 of the Plant-Specific Technical Guidelines with the following major revisions.

I. Page 2 - Incorporation of " Caution 6" regarding drywell temperature limits associated with RPV water level instruments.

II. Page 22 - Revision of PC/P-7 to include 65 psig as the emergency venting limit for the primary containment.

III. Pages 32, 33 - Revision of the Reactor Building Control Guideline requires the completion of Tables 1 and 2 (Tables 3 and 4 are no longer necessary).

l

. In addition, other minor changes have been made to make the P-STG consistent with plant instrumentation and temin-ology as well as incorporating some minor BWROG-EPG changes.

Finally, Attachment 3 to this letter provides various figures which are referenced in the P-STG and are being made available for information only.

i

e ATTACHMENT II

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