ML20076J403

RCS Vents (NUREG-0737,Item II.B.1), Final Technical Evaluation Rept

ML20076J403
Person / Time
Site:	Oyster Creek
Issue date:	04/06/1983
From:	Held J ENERGY, INC., LAWRENCE LIVERMORE NATIONAL LABORATORY
To:	Alberthal G NRC
Shared Package
ML20076J405	List: ML20076J403
References
CON-FIN-A-0250, CON-FIN-A-250, RTR-NUREG-0737, RTR-NUREG-737, TASK-2.B.1, TASK-TM TAC-44393, NUDOCS 8309060646
Download: ML20076J403 (5)

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' Selected Operating Reactor Issues Program II-Reactor Coolant System. Vent's (NUREG-00737, Item.II.B.l.)

NRC FIN A0250' - Project 9 FINAL TECHNICAL EVALUATION REPORT FOR OYSTER CREEK Docket Number 50-219 NRC TAC Number 44393 Prepared by J. T. Held of Energy Incorporated - Seattle (Subcontract 4324401) for Lawrence Livermore National Laboratory under contract to the NPC Office of Nuclear Reactor Regulation, Division of Licensing.

NRC Lead Engineer - Gus Alberthal NOTICE "This report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the United States Departmant of Energy, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsitrility for the accuracy, completeness or usefulness of any information, apparatus, product or process disclosed, or represents that its use would not infringe privately-owned rights."

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XA Copy Has Been Sent to PDR April 6, 1983 -

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- Jantai:y c.* CcHfornia P.O. est 308 Livermore, California 94550 C. Telephcne (415)4221100 'i Twx 910 306 8339, _ _ _ , ,

. . . Docket Numb:r 50-21?..

NRC TAC Numb r 44393

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TECHNICAL EVALUATION REPORT.

ON REACTOR COOLANT SYSTEM VENTS FOR OYSTER CREEK 9

INTRODUCTION The requirements for reactor coolant system high point vents are stated in porograph

.(cX3Xiii) of 10 CFR 50.44, " Standards for Combustible Gas Control System in Light-Water Cooled Power Reactors," and are further described in Standard Review Plan (SRP)

Section 5.4.12, " Reactor Coolant System High Point Vents," and item II.B.I of NUREG-0737, " Clarification of TMI Action Plan Requirements." In response to these and previous requirements, Jersey Centrol Power or.d Light Company has submitted information in References I and 2 in support of the vent system at the Oyster Creek Generating Station.

EVALUATION The function of the reactor coolant system (RCS) vent system is to vent noncondensible gases from the high points of the RCS to assure that core cooiing during natural circulation will not be inhibited. The Boiling Water Reactor (BWR) Owners' Group has submitted documentation (References 3 through 6) on how the RCS venting requirements are met in General Electric (GE) BWRs. The BWR Owners' Group position hos been endorsed by the licensee.

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In occordance with the BWR Owners' Group position, the primary means o.f. venting noncondensible gases from the reactor pressure vessel at Oyster Creek are five safety-grade power-opera ted relief volves that are part of the automatic depressurization system (ADS) and which alone provide od, equate venting.

We have reviewed design information on the volves ossociated with the obove system that will serve os RCS vents and confirmed that they are operable from- the main control room. We have also determined that the volves are provided with emergency power and that a degree of, redundancy in the RCS vent system is provided by powering different Enclosure 8 k2/TER-B-13 -

",ge I o f 4

vent paths from different emergency buses. NRC has previously verified that the relief

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volves are provided with positive volvd position indication in the main control room (Reference 7).

The cccumulation of a large amount of noncondensible gas within the tube side of the isolation condennr could cause th'e loss = of function of' the isolation condenser which

- provides diversity in core cocling methods. Thus, os summarized in Reference _8, bcsed on- the requirements of NUREG-0737 Item II.B.I Clarification B.(2) and perograph (cX3Xiii) of 10 CFR 50.44 remote ' venting of the isolotion condenser inside

' containment is required. The licensee has provided a conceptual design of a modification to allow remote venting of the isolation condenser inside containment following on occident. However, the conceptual design is not sufficiently detailed _ to determine compliance with the above requirements. This is on open item requiring receipt of the licensee's detailed isolation condenser high point vent modification design.

In addition, the licensee has foiled to verify that no other protection systems that are necessory to maintain adequate core cooling following on accident are susceptible to the buildup of a large ornount of noncondensible gas that could cause o loss of function of these systems and would therefore require remote venting. This otso is on open item.

CONCLUSION

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We conclude, based on the opplicobility of the BWR Owners' Group position to Oyster Creek and our specific review of the Oyster Creek design, that the existing systems at Oyster Creek are sufficient to effectively vent noncondensible gases from the RCS and meet the requirements of NUREG-0737 ltem II.B.I and porograph (c)(3)(iii) of 10 CFR 50.44, with two exceptions. First, the licensee must provide a detailed design description of the modifications. to the isolation condenser vents addressing ecc_h of the requirements of NUREG-0737 Item II.B.I. Second, the licensee must verify that no other .

protection systems necessary to maintain odequate core cooling following on occident are susceptible to the buildup of a large amount of noncorjdensible gas that could cause a loss of function of these systems. We therefore recommend following resolution of these two open items that the Oyster Creek RCS venting capability be found occeptable by NRC. It should be noted, however, that the following items were excluded from the scope of our review: seismic and environmental qualification, operating guidelines and procedures, and required modifications to the plant technicoi specific'otions and Enclose.-e 8 k2/TER-8-13 Poge 2 of 4

in-service inspectica prcgram for use of the existing ADS relief volves as RCS vents and for the' modified isolation condenser venf system. . . . .

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REFERENCES t' . ..... .

1. Letter, l. R. Finfrock, - Jr. (Jersey Centrol- ' Power' and - Light Company). ' to D.G. Eisenhut (NRC), " Followup to Reviews Regarding the Three Mile Island Unit 2 Accident," dated October 19,1979. ,

2. Letter, : 1.R. Finfrock, Jr. (Jersey Centrol Power and Light Company) to D.G. Eisenhut . (NRC), "NUREG-0578 . lmplementation - Oyster Creek Nuclear Generating Station," dated January 4,1980.

3. ' Letter, T.D. Keenan (BWR Owners' Group) to D.G. Eisenhut (NRC), "BWR Owners' Group Positions on NUREG-0578," dated October 17,1979.

4. Letter, D.B. Waters (BWR Owners' Group) to NRC (Attn: D.C. Eisenhut),

- " Preliminary Clarification of TMl Action Plan Requirements - BWR Owners' Group Cornments," dated October 8,1980.

5. General Electric Report NEDO-24708A, Revision I, - " Additional Information -

Required for NRC Staff Generic Report on Boiling... Water Reactors," dated December l'980.

6. Letter, D.B. Waters (BWR ' Owners' Group) to NRC (Attn: D.C. Eisenhut),

"NUREG-0660/0737 Requirement 11.B.1: Reactor Coolant System Vents," dated April 24,1981.

7. NUREG-0737. " Clarification of TMi Action Plan Requirements," Item II.D.3,

" Direct Indication of Relief- and Safety Volve Position," dated November 1980. ,

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8. NRC Memorandum, R.J. Mattson (Division of Systems Integration) to D.G. Eisenhut (Division of Licensing), " Requirement for BWR isolation Condenser Vents in Accordance with 10 CFR 50.44," dated March 8,198'3.

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