ML20043D250
| ML20043D250 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 05/29/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20043D249 | List: |
| References | |
| NUDOCS 9006070292 | |
| Download: ML20043D250 (5) | |
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UNITED STATES
-.E, NUCLE AR REGULATORY COMMISSION WMHINGTON, D. C. 20666 k...+/
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR _ REGULATION RELATED TO AMENDMENT NO. 139 TO PROYlSIONAL OPERATING LICENSE NO. DPR-16 GPU NUCLEAR CORPORATION AND JERSEY CENTRAL POWER & LIGHT COMPANY OYSTER CREEK. NUCLEAR GENERATING STATION DOCKET NO. 50-219 i
1.0 INTRpp0CTIO_N By letter dated May 16, 1989, GPU Nuclear Corporation (GPUN/ licensee) provided a commitment to propose, in a separate submittal, technical specification t
revisions to include surveillance requirements for System B of the control roomheating, ventilating,andairconditionin;l(HVAC) system,whichwasadded i
by refueling cycle 12R system upgrades.
By. letter d6ted October 3 1989, the NRCrequestedthatthelicenseesubmitapproariatetechnicalspecificationsfor chlorine detection and minimum air flow to tie control room for chlorine protection or provide acceptable justification for not providing the technical specifications, in a letter dated March 31, 1987, the licensee had agreed to comply with NRC request, that GPUN propose additional control room habit-ability (except dupers) is inoperable for more than seven days and on the technical specifications on plant shutdown if the control room HVAC 1
system maximum control room temperature, By letter dated October 18 1989, the licensee proposed technical specification revisionstoincludesurveIllancerequirementsforSystemBofthecontrolroom HVAC system. The licensee justified not providing (1) technical specifications l-for plant shutdown if the control room HVAC system (except dampers) is in-i operable for more than seven days, (2) maximum control room temperature, (3) chlorine detection and(4)minimumairflowtothecontrolroom. The licensee provided additional information, by letter dated February 21,1990, to justify not providing technical specifications for chlorine detection.
By letter dated February 27,1990, the NRC requested that, in accordance with their prior commitment, GPUN provide a submittal that evaluates control room operator thyroid exposures, in accordance with NUREG-0737, item Ill.D.3.4 requirements. By letter dated April 16,1985, the NRC had stated that because the staff was reviewing the iodine source term for the design basis loss-of-coolant accident, in the interim the licensee must meet only the 5 rem whole body and the 30 rem beta skin exposure limits to control room operators; the thyroid exposure limit would be addressed as a separate action from NUREG-0737 after the source term resolution.
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The proposed changes would affect Technical Specifications 3.17 and 4.17
" Control Room Heating, Ventilating, and Air Conditioning System." The changes would provide the following:
(1) that two control room HVAC systems be operable during all modes of plant operation; (2) new specifications for the control room HVAC systems; and i
(3) deletion of the surveillance to determine the makeup air plus infiltration air (less than or equal to 2000 cubic feet per minute) to the control room envelope for each control room HVAC system.
2.0 EVALUATION As a result of the 12R system u> grades, a second independent HVAC system (SystemB)hasbeenadded,whic1includesafan, dampers,andarefrigeration unit.
Each system has four manual operating modes: normal, purge, partial recirculation, and full recirculation. The safety functions of the control room HVAC system are:
(1) protect operators against the effects of an accidental release of toxic or radioactive gases; and (2) provide a habitable environment so that the plant can be safely operated or shut down under design basis accident conditions.
The present technical specifications recognize only a single system.
The installation of a separate system provides remedial measures to address a potential single failure of an active component in either system. The control room HVAC systems share common passive equipment.
New specifications for the control room HVAC system are proposed as described and evaluated below.
(1) Where the current specification provides that the dampers be manually aligned for the partial recirculation mode of operation when the single system is inoperable, the proposal would require, with one control room HVAC system inoperable, that the operable system be placed in the partial recirculation mode, or t1at the operability of the partial recirculation mode be demonstrated once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The licensee stated that, since the supply fan runs continuously in the normal and partial recirculation modes, its inoperability would be immediately apparent to the control room operators. Therefore, the failure of the dampers to realign the partial recirculation mode of operation is the area of concern subsequent to a release of radioactivity within the reactor building.
This new specification would provide a level of assurance of the capability of the operable system to perform its design function during a design basis accident. The staff concurs with this evaluation.
. (2) The proposal would add the requirements, with both HVAC systems inoperable, that the reactor be placed in the cold shutdown condition within 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />, and, during refueling, irradiated fuel handling operations cease, and all work cease on the reactor or its connected systems in the reactor building which could result in inadvertent releases of radioactive materials. The staff considers that this provision satisfies the licensee's commitment to propose a technical specification on plant shutdown if the control room HVAC system is inoperable.
Further, the proposed amendment would retain the surveillance requirement for verifying, in the partial recirculation mode of operation, that the control room and lower cable spreading room are maintained at a positive pressure of greater than or equal to 1/8 inch water gege relative to the onsite l
atmosphere. However, the provision which requires that the specific positive pressure be maintained with the total flow rate of makeup air plus infiltration air less than or equal to 2000 cubic feet per minute would be deleted.
The licensee stated that they have reviewed the radiological analysis to determine the limiting air flow rate for the partial recirculation mode of operation. The results of these calculations demonstrated that the beta and gama doses reracin telow their respective limits even with 100% outside air i
for 30 days. The licensee concluded, based on this analysis that the current technical specification limit of 2000 cubic feet per iainute Is not warranted and, therefore, should not be considered a factor for determining the operability of either control room HVAC system. The staff has performed an independent analysis of the control room operator doses and concurs with the licensee's conclusion.
The licensee stated that the need has been identified for control room air temperature control during normal operations and that it has revised station procedures to provide precautions and remedial actions for a loss of normal ventilation. Since the existing station procedures already recognize the importance of the control room temperature during normal plant operations, an additional technical specification requirement is not warranted. The standard technical specifications require verification every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> that the controlroomairtemperatureislessthanorequalto(120)'F.
This acceptance criterion temperature is based on environmental considerations concerning essential equipment in the control room.
In practice, however, incre-detailed procedures are needed to implement this requirement as well as to assure that air temperatures remain in the range appropriate for the operators, which is well below the technical specification limit. The staff, therefore, concurs with the licensee's conclusions.
The staff requested that GpVN submit appropriate technical specifications for chlorine detection and minimum air flow to the control room for chlorine protection, based on the fact that the licensee removed only the 1-ton liquid chlorine cylinders and retained a 150-pound cylinder to treat the new radwaste service water system. The licensee performed an analysis of chlorine gas concentrations in the control room envelope considering instantaneous and continuous releases of chlorine from the 150-pound tank. The licensee stated that a chlorine detector is provided within the chlorine storage enclosure, which alarms at the chlorine room on detection of chlorine. Procedures require that the corJ'o1 room operators in response to a chlorir.e alarm den protective breathing apparatus and tranuall initiate the full recirculation, mode if not
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. already'in effect. Procedures also require that the control room HVAC system be in the full recirculation mode during chlorine system maintenance, tank l
delivery, and tank handling. The refueling cycle 12R control room HVAC tests i
have demonstrated a makeup air plus infiltration rate less than 1750 cubic feet per minute for the full recirculation mode with the kitchen / toilet exhaust fan off. A timer on the fan switch limits continuous operation to a maximum of five minutes. The li:ensee's analysis conservatively assumed that the wind direction causes the maximum concentrations of chlorine at ground level to
. move from the chlorine cylinder directly toward the control room outside air intake. The enclosure that houses the cylinder is located at ground level, 380 feet northwest of the control room air intakes. The intakes are located on the roof of the office building at elevations 64 and 73 feet. There are tanks and buildings between the cylinder enclosure and the air intakes with heights up to 100 feet. There is no straight line path from the chlorine cylinder to the control room; and the local obstructions produce a large-scale turbulence that alters the wind path. The analysis further conservatively takes no credit for the effects of the enclosure that houses the chlorine cylinder or for the mixing of the chlorine plume due to building wake effects.
The results of the licensee's analysis show that the Regulatory Guide 1.78 toxicity limit concentration of chlorine (15 parts per million) is not attained in the control room envelope until after two minutes have elapsed following the alarm in the control room after assumed instantaneous or continuous (3/8-inchlinebreak) releases.
Regulatory Guide 1.78 provides that a minimum operator response time of two minutes should be provided to allow the o>erators to don protective breathing apparatus. The licensee also stated tiet, as per Regulatory Guide 1.78, the air exchange rate of the control room (3.8 changes per hour at an infiltration rate of 1750 cubic feet per minute) does not require verification by field testing. The licensee concluded, based on the above, that technical specifications for chlorine detection and minimum air flow to the control room are not needed for chlorine protection. The staff has performed independent analyses of chlorine concentrations in the control room for postulated instantaneous and continuous releases. Based on the staff review of the licensee's evaluation and the results of the staff's independent analyses, the staff concurs with the licensee's conclusions.
Based on the above evaluation, the staff concludes that the licensee's proposal meets the intent of GDC 19 (except for consideration of control room o)erator thyroid exposures) and the Standard Technical Specifications and, tierefore, is acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
Pursuant to 10 CFR 51.21, 51.32 and 51.35, an environmental assessment and finding of no significant impact have been prepared and published in the Federal Register on May 24, 1990 (55 FR 21465). Accordingly,; *rd upon the environmental assessment, we have determined that the issus.e of the amendment will not have a significant effect on the quality of the human environment.
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4.0 CONCLUSION
The staff has concluded, based on the considerations discussed above, that (1) there is reasonable assurance that the health and safety of the will not be endangered by operation in the proposed manner, and (2) public such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendnent will not be inimical to the common defense and security nor to the health and safety of the public.
4 Dated: May 29, 1990 Principal Contributor:
C. Nichols g.
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