ML20196G016
| ML20196G016 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 05/01/1997 |
| From: | Kraft E COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20196G022 | List: |
| References | |
| ESK-97-086, ESK-97-86, NUDOCS 9705130229 | |
| Download: ML20196G016 (8) | |
Text
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Osmmonwcalth 12hwin Osmpany Quad Citics Generating Station 2,2710 206th Menue North Gordova, !!. 612 (2-9740 Tel 309M 4-2241 ESK-97-086 May 1,1997 United States Nuclear Regulatory Commission Washington, DC 20555 Attention:
Document Control Desk
Subject:
Quad Cities Nuclear Power Station Units 1 and 2 Request for Amendment to Facility Operating Licenses DPR-29 and DPR-30, Appendix A, Technical Specifications (TS), Section 4.9.A.8.b, Clarification of Diesel Generator Single Load Rejection Test Surveillance Requirements NRC Docket Nos. 50-254/265 l
References:
(a)
P. L. Piet letter to U. S. Nuclear Regulatory Commission dated November 14,1995, concerning Supplement to Application for Amendment related to Technical Specification Upgrade Program (TSUP).
l (b)
R. M. Pulsifer letter to D. L. Farrar, dated June 28,1996, concerning Issuance of Amendments Related to Technical Specification Upgrade Program (TSUP).
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Pursuant to 10 CFR 50.90, Comed proposes to amend Appendix A, Technical j
Specifications Surveillance Requirement (SR) 4.9.A.8.b, of Facility Operating Licenses
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l DPR-29 and DPR-30. The purpose of this amendment request is to revise the requirements in SR 4.9.A.8.b. In the reference (a) submittal, Comed proposed testing l
requirements (specifically load value to be rejected) for the single load reject
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surveillance, which were based on calculated values. In the Reference (b) amendment
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approval by the NRC staff, the current SR was accepted. This change will revise the load value for the diesel generator to be equal to or greater than the largest single load and revise the frequency and voltage requirements during performance of the test. The changes allow for testing that will more closely simulate actual emergency loading
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conditions and provide greater assurance that the diesel generator can successfully perform during and after a transient.
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9705130229 970501 PDR ADOCK 05000254-
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U.S. NRC ESK-97-086 2
May 1,1997 i
The proposed Technical Specification Amendment is subdivided as follows:
- 1. Attachment A gives a description and safety analysis of the proposed changes.
- 2. Attachment B includes the proposed changes to the Technical Specifications pages, including marked-up versions of the current pages.
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- 3. Attachment C describes Comed's evaluation performed in accordance with 10 CFR 50.92(c), which confirms that no significant hazards consideration is involved. In
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addition, Comed's Environmental Assessment Applicability Review is included.
This proposed Technical Specification amendment has been reviewed and approved by i
Comed On-Site and Off-Site Review in accordance with Comed procedures.
To the best of my knowledge and belief, the statements contained above are true and correct. In some respect these statements are not based on my personal knowledge, but obtained information furnished by other Commonwealth Edison employees, contractor employees, and consultants. Such information has been reviewed in accordance with company practice, and I believe it to be reliable.
Comed is notifying the State ofIllinois of this application for amendment by transmitting a copy of this letter and its attachments to the designated state oflicial.
Please direct any questions you may have concerning this submittal to Charles Peterson, Regulatory Affairs Manager, at (309) 654-2241. extension 3609.
Respectfully,
&.lbtD a.
E, S. Kraft, r.
Site Vice-President Quad Cities Station Subscribed and Sworn to before me on this 6
day of 4L 2c
,1997.
b,5 EA&
l Notary Public
" OFFICIAL SEAL" UNDALEESTOWWER NetsyPubec, State of Enels ner cear m e n m ensei m e m oe l
U.S. NRC ESK-97-086 3
May 1,1997 Attachments: A. Description and Safety Analysis of the Proposed Changes B.
Marked-Up Technical Specification Pages C.
Evaluation of Significant Hazards Considerations and Environmental '
Assessment Applicability Review cc:
A. B. Beach, NRC Regional Administrator, RIII R. M. Pulsifer, Project Manager - NRR C. G. Miller, Senior Resident Inspector - Quad Cities D. C. Tubbs, MidAmerican Energy Company W. D. Leech, MidAmerican Energy Company F. A. Spangenberg, Regulatory Affairs Manager, Dresden P. L. Piet, Nuclear Licensing Administration DCD - License (Both electronic and hard copy)
ESK Letter File
ATTACHMENT A DESCRIPTION AND SAFETY ANALYSIS OF THE PROPOSED CHANGES ESK-97-086 Page 1 of 4 Description of the Proposed Change i
Pursuant to 10 CFR 50.90, Comed proposes to amend Appendix A, Technical Specifications Surveillance Requirement (SR) 4.9.A.8.b, of Facility Operating License DPR-29 and DPR-30.
The purpose of this amendment request is to clarify the load to be rejected and the parameters to l
be met for the diesel generator single load reject SR 4.9. A.8.b. In the reference (a) submittal,
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Comed proposed testing requirements (specifically load value to be rejected) for the single load j
reject surveillance, which were based on calculated values. In the past, during performance of this l
test, the Residual Heat Removal Service Water (RHRSW) pump was powered from the Main 4KV Bus via offsite power and not by the diesel. In this configuration it was not practical or desired to reject the actual largest load. Instead, a combination ofloads with an equivalent load rating normally powered by the diesel generator were previously rejected. Planned changes in test configuration will allow for the diesel generator to provide power to the Main 4kV Bus as well as supplying'its normal emergency loads on the 4kV ECCS Bus. While in this configuration, the i
largest single load (RHRSW pump) that the diesel generator is analyzed to carry during a loss of coolant accident (LOCA) combined with a loss of offsite power (LOOP) will be rejected.
Description and Bases of the Current Operatine Licensefl'echni. cal SDecification Reauirement Technical Specification Surveillance Requirement 4.9.A.8.b requires verification of the capability of the diesel generator to reject the largest single emergency load while maintaining frequency and voltage within set values. The value designated in the SR as the largest load is currently greater than or equal to 725 kW. The nameplate horsepower rating for the largest load (RHRSW Pump) is 900. This calculates to a load rating of 721.9 kW. This was rounded up for the Technical Specification to be conservative. Each diesel generator is provided with an engine overspeed trip to prevent damage to the engine. Recovery from the transient caused by the loss of a large load could cause diesel engine overspeed, which, if excessive could cause a trip of the engine. This surveillance requirement demonstrates the diesel generator load response characteristics and capability to reject the largest single load without exceeding predetermined voltage and frequency j
and while maintaining a specified margin to the overspeed trip. The voltage and frequency values are derived from Regulatory Guide 1.9.
ATTACHMENT A DESCRIPTION AND SAFETY ANALYSIS OF THE PROPOSED CHANGES ESK-97-086 Page 2 of 4 Descriotion of the Need and Bases for Amending the Technical SDefifiestions Comed proposes to remove the load value from Technical Specification Surveillance Requirement 4.9.A.8.b, diesel generator largest single emergency load rejection test.
Additionally, the frequency and voltage requirements will be revised to reflect steady state values l
which will allow minor excursions during the load rejection. Verification of the maximum frequency during the rejection will not be changed. The value in the Technical Specifications for i
the largest single load is currently greater than or equal to 725 kW. The nameplate horsepower rating for the largest load (RHRSW Pump) is 900. This calculates to a load rating of 721.9 kW.
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This was rounded up for the Technical Specification to be conservative.
j Previous tests have been perfonned by rejecting multiple loads simultaneously to achieve an j
equivalent load rating. Originally, this was performed using a Core Spray pump and a Residual Heat Removal (RHR) pump operating at minimum flow. Because of time constraints associated with operation of these pumps at minimum flow (pumps can be operated on minimum flow for up to 10 minutes without performing vibration measurements to ensure pumps are not damaged),the method of testing was revised to allow the pumps to operate at full flow using a test flow path during the simulation of a LOCA combined with a LOOP. Higher flows equated to a higher load profile for the diesel generator. This method of testing also allowed the loading of the diesel generator to simulate more closely actual conditions during a LOCA combined with a LOOP.
When the largest load rejection was performed at the higher flow rate, the diesel generator voltage would exceed the specified value. Repeated testing was required in order to reduce the load rating closer to the specified value of 725 kW because adjustment of the two pumps to flow rates somewhere between full and minimum flow was required. In order to minimize the transients on the plant equipment (Core Spray and RHR pumps, diesel generator), it is proposed to continue to limit the maximum frequency during the transient to the current value of 66.73 Hz, but eliminate the voltage requirement during the transient. Eliminating the voltage requirement is acceptable because the purpose of the test is still met; i.e. the diesel's ability to provide power to ac loads is demonstrated. Following the load rejection, the steady state voltage and frequency are to be verified to be maintained at 41601420 volts and 60 1.2 Hz, respectively. The bases will be enhanced to specify the load that is considered to be the largest single emergency load as well as its nameplate horsepower rating. Methods of performance of the rejection will be specified which would allow either the specific load or equivalent load to be rejected as determined by plant conditions.
ATTACHMENT A DESCRIPTION AND SAFETY ANALYSIS OF THE PROPOSED CHANGES ESK-97-086 Page 3 of 4 The proposed amendment to Quad Cities Station's Technical Specifications is based on current surveillance requirements in LaSalle, Braidwood, and Byron Station Technical Specifications.
The requirements in these tests demonstrate the ability of the diesel generator to continue to provide AC power to the required emergency loads during the loss of the largest load. Quad Cities Station intention is to simulate diesel generator loading as closely as possible for a LOCA combined with a LOOP while rejecting the largest single load. Performance of this test while in l
this configuration will ensure that the diesel generator will be capable of continued operation i
during an actual event. Previous testing experience has shown that the diesel generator will be capable cf supplying AC power to remaining loads following rejection ofloads that are greater j
than the largest single emergency load without loss of function of any remaining equipment. The diesel generator did not overspeed during this testing, however, voltage exceeded the maximum value of 4580 volts. The time for the voltage to return within its acceptable steady-state value of 41601420 volts is approximately one second Guidance provided in Regulatory Guide 1.9, revision 3, regulatory position 1.4 states:
".. Frequency should be restored to within 2 percent of nominal in less than 60 percent of each load-sequence interv. ' for stepload increase and in less than 80 percent of each load-sequence interval for disconnection of the single largest load, and voltage should be restored to within 10 percent of nominal within 60 percent of each load-sequence time interval...During re.overy from transients caused by the disconnection of the largest single load, the speed of the diesel generator unit should not cxceed the nominal speed plus 75 percent of the difference between nominal speed and the over-speed trip setpoint or 115 percent ofnominal, whichever is lower..."
Based on the information previously stated, the diesel generator frequency should not exceed the nominal speed (900 rpm) plus 75 percent of the difference between nominal speed and the l
overspeed trip setpoint (0.75 x (1035 - 900) + 900 = 1001.25 rpm) or 115 percent of nominal (1.15 x 900== 1035 rpm) whichever is lower. Current Technical Specifications state that the frequency must remain below 66.73 Hz.
Frequency
= {(speed in rpm) x (# generator poles)} + 120 l
= {l001 x 8} + 120
= 66.73 Hz 4
ATTACHMENT A DESCRIPTION AND SAFETY ANALYSIS OF THE PROPOSED CHANGES ESK-97-086 Page 4 of 4 Testing will continue to verify the diesel generator frequency response remains below this maximum value. Additionally, the frequency should return to within 2 percent ofnominal(60 1.2 Hz) within 80 percent of the load sequence interval. For Quad Cities the allowable frequency recovery time is less than or equal to 4.0 seconds (0.80 x 5.0=4.0). Changes to the testing requirements will verify that the steady-state frequency is within this band within the specified time. Likewise, voltage will be verified to return to within 10 percent of nominal (4160 420 volts) within 60 percent of the load-sequence interval. For Quad Cities the allowable voltage
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recovery time is less than or equal to 3.0 seconds (0.60 x 5.0=3.0). Changes to the testing requirements will verify that the steady-state voltage is within this band within the specified time.
Therefore, these changes are consistent with the intent of the purpose of the single load rejection test.
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ATTACHMENT B PROPOSED AMENDMENTS TO THE LICENSE / TECHNICAL SPECIFICATIONS ESK-97-086 Page1of1 LICENSE DPR-29/30 Page 3/4.9-5 B 3/4.9-3 i
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