ML20151X250
| ML20151X250 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 07/28/1988 |
| From: | Olshan L Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20151X189 | List: |
| References | |
| NUDOCS 8808250291 | |
| Download: ML20151X250 (8) | |
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I 7590-01 UNITED STATES NUCLEAR REGULATORY COMMISSION ILLINOIS POWER COMPANY, ET AL DOCKET NO. 50-461 ENVIRONMENTAL ASSESSMENT AND FINDING OF NO SIGNIFICANT IMPACT The U.S. Nuclear Regulatory Connission (the Connission) is considering issuance of an amendment to the Illinois Power Company *(IP), Soyland Power Cooperative Inc. and Western Illinois Power Cooperative, Inc. (the licensees) for Clinton Power Station Unit 1, located in DeWitt County, Illinois.
ENVIRGNMENTAL ASSESSMENT Identification of Proposed Action:
In general, the proposed license amendmentwouldrevisetheTechnicalSpecifications(TS)relatedtocontainment ventilation and drywell purge (VR/VQ) system isolation valves.
Specifically, the licensees proposed (1) deletion of the operability and surveillance requirements for the 50* stops installed for the VR/YQ valves, (2) insertion of footnotes in the limiting conditions for operation and applicable surveillance requiresents to exclude the time when the VR/VQ valves are opened for performing stroke-time testing, and (3) extension of the administrative control permitting opening of the VR/VQ valves.
- Illinois Power Company is authorized to act as agent for Soyland Power Coorperative, Inc. and Western Illinois Pow r Cooperative. Inc. and has exclusive responsibilit) and control over the physical construction, operation and maintenance of the facility.
8900250291 800009 DR ADOCK 05000 1
7590-01,
This revision to the Clinton Power Station license would be made in response to the licensees' application for amendment dated October 30, 1987.
The Need for the Proposed Action: Pursuant to 10 CFR 50.90. IP, et al.
have proposed an amendsent to Facility Operating License No. NPF-62 which consists of three changes to the TS concerning the containment ventilation and 4
drywell purge system isolation valves. The first change would delete the requirements associated with the YR/VQ valve opening angle restriction in footnote 1 (one asterisk) of TS 3.6.1.8 (limiting conditions for operations)
I and in TS 4.6.1.8.2 (surveillance requirements), and would revise footnote 2 (twoasterisks)ofTS3.6.1.8.
Footnote 1 of TS 3.6.1.8 requires that the 36-inch containment ventilation supply and exhaust valves be blocked to prevent them from opening more than 50'.
The surveillance requirements of TS 4.6.1.8.2 require that the 50'
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valve-opening restriction for the 36-inch containment ventilation supply and exhaust valves be verified at least once every 31 days. The licensees propose to remove these requirements from the TS.
Footnote 2 of TS 3.6.1.8 states that containment ventilation system operation shall be defined as any time the 36-inch supply and/or exhaust isolation valves are opened. The licensees propose to insert the following statement to footnote 2: "except when opened l
for inservice testing performed pursuant to TS 4.0.5".
By letter dated July 20, 1983, the staff infonned the licensees that the use of the 24-inch and 36-inch purge valves would be acceptable during l
operational modes 1, 2, and 3 if the valves were blocked to a maximum opening angleof50'(90'correspondstofullyopen).
In its letter dated l
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November 17, 1983, the licensees connitted to install mechanical stops on the valves to limit them from opening more than 50' during operational modes 1, 2, and 3.
The 50' stops could be removed during modes 4 and 5 if increased purge flow were required during maintenance activities. The staff found the licensees' cosmitment acceptable as indicated in Supplement 5 to the Clinton Supplemental Safety Evaluation Report (SSER 5) dated January 1986. The licensees incorporated the appropriate operability and surveillance requirements for the 50' stops into the TS.
Subsequently, the licensees found that purge flow was adequate during modes 4 and 5 with the 50' stops in place and thus, periodic removal of the 50' stops to increase purge flow as originally suggested would not be needed.
Therefore, the licensees proposed to modify the 50' stops so that they are a permanent part of the installation of the valves and to delete the requirement for confirmation of the 50' opening angle limitation in the TS. The licensees r.lso proposed to revise the bases for TS 3/4 6.1.8 to specify that the blocking devices are pennanently installed on the 36-inch purge valves.
TS 3.6.1.8 requires that the opening of the containment building ventilation (36-inch)isolationvalvesforcontainmentventilationsystem operation be limited to less than or equal to 500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br /> per year. System operation is defined by TS 3.6.1.8 as any time the valves are open. TS 4.0.5 requires that these valves be tested according to the inservice testing (IST) program by perfonning stroke-time testing every 92 days. The IST is performed such that the valves are open one at a time for stroke time verification while
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the other valve in series is closed. The licensees propose to exclude the time when these valves are opened to complete stroke-time testing from thi l
cumulative system operation time limits currently specified in TS 3.6.1.8.
The second change would delete footnote 1 (one asterisk) and revise footnote 2 (two esterisks) in TS 3.6.2.7 (limiting conditions for operation),
anddeleteTS4.6.2.7.4(surveillancerequirements)anditsfootnote.
Foonote 1 requires that the 24-inch drywell vent and purge supply and exhaust isolation valves and the 36-inch outboard isolation valves be blocked to prevent them from opening more than 50'.
Footnote 2 specifies that drywell vent system operation shall be defined as any time either the 10-inch or the 24-inch inboard exhaust valves are open when all valves mentioned in TS 3.6.1.8 are closed. The licensees propose to revise footnote 2 by adding the following: "This excludes the time when either of these valves is opened for inservice testing performed pursuant to TS 4.0.5 (concurrent with all valves of TS 3.6.1.8 closed)."
The surveillance requirements of TS 4.6.2.7.4 state that at least once every 31 days, the 24-inch drywell vent and purge supply and exhaust valves and the 36-inch outboard isolation valves shall be verified to be blocked in order to restrict valve opening to less than or equal to 50'.
The footnote for TS j
4.6.2.7.4 also specifies that the blocking device for the 24-inch valves shall l
be verified installed prior to drywell closing and during each cold shutdown
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except such verification need not be performd more often than once every 92 days. The licensees propose to delete TS 3.6.2.7.4 and footnote 1 of TS 3.6.2.7 associated with the 50' valve opening angle limitation since the 50' stop device will become part of the permanent valve installation.
s 7590-01
- 8 TS Table 3.6.4-1, note (a) states that certain containment isolation valves may be open on an intennittent basis under administrative control. The third change would extend the application of this note to include the VR/VQ valves since they are needed to be opened while certain local leakrate tests are conducted. Note (a) would be inserted into Table 3.6.4-1 for valves 1YR002A.-B and IVQOO6A,-B to allow them to be opened under administrative control during the perfonnance of leak testing associated with the 36-inch containment ventilation supply and exhaust valves every 92 days as specified in TS 4.6.1.8.3.
Environmental Impacts of the Proposed Action:
Because the 50' mechanical stops for these valves were previously approved by the staff (as discussed in SSER 5) and are a part of the pennanent valve installation, the staff finds the elimination of the operability and surveillance requirements for the 50' stops in TS 3.6.1.8 and TS 4.6.1.8.2 to be acceptable. The staff also agrees with the revised bases for TS 3/4 6.1.8 because of the permanent installation of the blocking device on these valves.
The staff finds the proposed revision to footnote 2 of TS 3.6.1.8 acceptable because valve testing in accordance with the IST requirements does not require the containment ventilation system to be operable. Therefore, stroke-time testing should not be considered part of the system operation time limit.
The staff finds the proposed deletion of TS 3.6.2.7.4 and footnote 1 of TS 3.6.2.7 associated with the 50' valve opening angle limitation acceptable because the 50' stop device will become part of the permanent valve installation and cannot be removed.
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l TS 3.6.2.7 requires that the opening of the drywell vent and purge system (24-inch or 10-inch) isolation valves for drywell vent system operation be limited to 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> per year. The basis for limiting the amount of time the valve can be opened for drywell vent system operation is to limit the release of radioactivity to the environs during normal operating conditions. The staff finds that the revision to footnote 2 of TS 3.6.2.7 to exclude the IST stroke-time tests from the system operation time is acceptable, because stroke-time testing per the IST program does not require the drywell vent and purge system to be operable.
The VR/VQ valves are part of the test boundary for the 36-inch containment ventilation supply and exhaust valves. Also, when these valves are being leak tested, the 36-inch valves must be closed so that the penetration will remain effectively closed during the test. The staff finds extending the application of note (a) to the valves specified above acceptable because the valves are required to be opened during the local leakrate testing of the 36-inch ventilation system isolation valves every 92 days.
The Comission has determined 'that potential radiological releases during normal operations, transients, and for accidents would not be increased. With regard to non-radiological impacts, the proposed amendment involves systems located entirely within the restricted area as defined in 10 CFR Part 20. They l
do not effect non-radiological plant effluents and have no other environmental I
impact. Therefore, the staff also concludes that there are no significant non-radiological environmental impacts associated with the proposed ascendment.
Accordingly, the Connission findings in the "Final Environmental Statement related to the operation of Clinton Power Station, Unit No.1" dated May 1982
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regarding radiological environmental impac*s from the plant during nonnal operation or after accident conditions, are not adversely altered by this action.
IP is comitted to operate Clinton, Unit 1 in accordance with standards and regulations to maintain occupational exposure levels "as law as reasonably achievable."
Alternative to the Proposed Actions: The principal alternative would be to deny the requested amendment. This alternative, in effect, would be the same as a "no action" alternative. Since the Comission has concluded that no adverse environmental effects are associated with this proposed action, any alternative with equal or greater environmental impact need not be evaluated.
Alternative Use of Resources: This action does not involve the use of resources not previously considered in connection with the Nuclear Regulatory Comission's Final Environmental Statement dated May 1982 related to this facility.
Agencies and Persons Consulted: The NRC staff reviewed the licensees' request of October 30, 1987 and did not consult other agencies or persons.
FINDING OF NO SIGNIFICANT IMPACT: The Comission has detennined not to prepare an environmental impact statement of the proposed license amendment.
Based upon this environmental assessment, the Comission concludes that the proposed action will not have a significant adverse effect on the quality of the human environment.
For further details with respect to this action, see the request for amendment dated October 30, 1987 and the Final Environmental Statement for the Clinton Power Station dated May 1982, which are available for public inspection i
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i 7590-01 8-V at the Comission Public Document Room,1717 H Street, N.W., Washington, D.C.
20555 and at the Vespasian Warner,120 West Johnson Street, Clinton, Illinois 61727.
Dated at Rockville, Maryland this 28th day of July 1988.
FOR THE NUCLEAR REGULATORY C0m !SSION bklk'.Olsben,ActingDirector.
h Leonard N Project Directorate III-2 Division of Reactor Projects - III, IV, Y and Special Projects l
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