ML20113C275
| ML20113C275 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 06/27/1996 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20113C273 | List: |
| References | |
| NUDOCS 9607010095 | |
| Download: ML20113C275 (5) | |
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t UNITED STATES g
NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 300eH001
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SAFETY EVALUATION BY THE OFFICE 4 lUCLEAR REACTOR REGULATION 3
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RELATED TO AMENDMH'd NO.129 d
l E FACILITY OPERATING LICENSE NO. NPF-49 NORTHEAST NUCLEAR ENERGY COMPANY. ET AL.
f M11LSTONE NUCLEAR POWER STATION. UNIT NO. 3 I
t DOCKET NO. 50-423
1.0 INTRODUCTION
By letter dated June 27, 1995, as supplemented July 21, 1995, the Northeast Nuclear Energy Company, submitted a request for changes to the Millstone Nuclear Power Station, Unit No. 3 Technical Specifications (TS). The requested changes would revise the TS to relocate containment purge exhaust and supply valves TS requirements, and to remove a dup inte testing requirement for the safety injection input from engineet J safety features (ESF) from the TS, 2.0 EVALUATION 2.1 Relocation of Reauirements for Containment Hiah Ranoe Radiation Monitors The licensee proposed to relocate the operability and surveillance requirements for the containment high range radiation moni?. ors (3RMS*RE41 and 3RMS*RE42) from TS Section 3/4.3.3, " Monitoring Instrumenta'. ion - Radiation Monitoring for Plant Operations," to TS Section 3/4.3.2, " Engineered Safety Features Actuation System Instrumentation." This change was initiated following an investigation of the December 10, 1991, failure of radiation monitor 3RMS*RE41, which resulted in the automatic closure of the containment purge exhaust ar.d supply valves. After reviewing the reporting criteria unaer 10 CFR 50.73(a), the licentee initially determined that the event should be classified as non-reportable. However, subsequent evaluations concluded that the event described was an ESF actuation which must be reported pursuant to 10 CFR 50.73(a)(iv). The lic'ensee's misclassification of the event was Ottributed to the fact that the requirements for the containment purge exhaust and supply valves were not located in the. ESF TS tables.
The containment purge supply and exhaust isolation valves are part of the Containment Isolation System. These valves are normally closed during powe operation and are designed to close automatically during cold shutdown on N high radiatf on signal from the containment area radiation monitors.
1 Currently, the TS requirements for the containment purgc moly and exhaust L
isolation Wves are located in the Radiation Monitorim, Im.icumentation iS 94 M010095 960627 3
NH ADOCK 05000423 P
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j tables.
In Chapter 6 of the Millstone Unit 3, Final Safety Analysis Report (FSAR), the Containment Isolation System is identified as an ESF.
To avoid
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additional errors in reporting, the licensee proposed to move the containment j
purge exhaust and supply valves TS requirements to the ESF Instrumentation TS tables.
The licensee proposed the following changes to remove all of the 4
containment purge exhaust and supply valve requirements frem the Radiation Monitoring portions of TS:
(1)
Table 3.3-6, " Radiation Monitoring Instrumentation for Flant Operations" j
(a)
Delete line item la, Containment Area Purge and Exhaust Isolation i
j (b)
Delete Action 26 from " Action Statements" l
(2)
Delete line item la, Containment Area Purge and Exhaust Isolation, from l
Table 4.3-3, " Radiation Monitoring Instrumentat. ion for Plant Operations l
Surveillance Requirements" l
(3)
Remove "or automatic isolatim action and actuation of Emergency Exhaust or Ventilation System" from tFa latter part of the last sentence in TS Section 3/4.3.3.1, " Radiation Monitoring for Plant Operations." The last sentence would read "Once the required locic combination is completed, the system sends actuation signals to initiate alarms."
The licensee proposed the following changes to add all of the containment purge exhaust and supply valve requirements to the ESF portions of the TS.
With the exception of a few editorial changes, the new table values and table notes were taken directly from the Radiation Monitoring TS tables:
(1)
Table 3.3-3, " Engineered Safety Features Actuation System Instrumentation" (a)
Add an item to line item 3, Containment Isolation, that would describe the purge isolation as having 2 total number of channels, I trip channel, 2 minimum channels required operable, Modes 5 and 6 as the applicable modes (with a reference to change Ib below), and Action 26 (with a reference to change Ic below).
The table details were obtained from Table 3.3-6.
(b)
Add a note to the table to clarify that in addition to Modes 5 and 6, the Action Statements are also applicable dring core alterations and movement of irradiated fuel within the containment. Also noted, the provi: ions of Specification 3.0.3 are applicable only in Modes 1 through 4.
(c)
Add Action 26 from Table 3.3-6 to the Action Statements list.
The first sentence would be reworded for clarity.
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[ l (2)
Table 3.3-4, " Engineered Safety Features Actuation System Instrumentation Trip Setpoints" - Add an item to line item 3, j
Containment Isolation, that would denote the trip setpoint and allowable j
value to be $1R/h which is obtained from Table 3.3-6.
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(3)
Table 4.3-2, " Engineered Safety Features Actuation System Instrumentation Surveillance Requirements" (a)
Add an item to line item 3, Containment Isolation, to describe the purge isolation Surveillance Requirements to include a semi-i annual channel check, a refueling outage channel calibration, a quarterly analog channel operational test, and Modes 5 and 6 for i
which surveillance is required (with reference to change 3b below).
(b)
Add a note to specify that in addition to Modes 5 and 6, the 4
Actions are also applicable during core alterations and movement of irradiated fuel within the containment.
It was also noted that the provisions of Specification 3.0.3 are not applicable (only applicable in Modes I through 4).
The NRC staff has determined that the change relocates previously approved TS requirements from one TS table to another and is therefore, acceptable.
2.2 Removal of Duplicate Testina Reemirements for Safety Iniection BI)
Inout f.om ESF The licensee proposed to remove line item 16, Safety injection (SI) Input from ESF, from TS Table 3.3-1, " Reactor Trip System (RTS) Instrumentation", and from TS Table 4.3-1, "RTS Instrumentation Surveillance Requirements." As indicated in Table 4.3-1, the TS currently require that a trip actuating device operational test (TADOT) be performed on an 18-month frequency for line item 16. As defined in the TS, a TADOT consists of operating the trip actuating device and verifying operability of alarm, interlock, and/or trip functions.
A reactor trip occurs when the SI system is manually or automatically actuated. Automatic SI actuaticn is initiated by high containment pressure, low compensated steamline pressure, or pressurizer low pressure. The licensee stated that there is no single trip actuating device associated with the automatic SI actuation signal to cause a reactor trip.
Instead, the signal originates as three separate inputs from the three pressure signals that cause an automatic SI actuation.
Likewise, the manual SI actuation signal, which is generated by pressing two pushbuttons in the main control room, is fed directly to the reactor trip instrumentation to cause a reactor trip. A requirement for a TADOT for " Safety Injection Input from ESF" is very misleading since it does not correspond to a single device.
In addition, a TAD 0T is not specified for any other automatic reactor trip signal.
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The safety injection signal is listed as a reactor trip in FSAR Table 7.2-1,
" List of Reactor Trips." However, the safety injection signal is not listed I
along with the other reactor trip signals as having associated instrumentation
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in FSAR Table 7.2-3, " Reactor Trip System Instrumentation."
In addition, FSAR l
Figure 7.2-1, Sheet 8,
- Safeguards Actuation Signals," shows four separate j
signals going directly to the reactor trip instrumentation - high containment i
pressure, low compensated steamline pressure, pressurizer low pressure, and manual SI actuation. This confirms that there is no single trip actuating i
device associated with an automatic SI actuation signal to cause a reactor l
trip.
I The licensee stated that the current testing associated with "SI Input from ESF' (Table 4.3-1, Item 16) is duplicated by the following line items:
(1)
Table 4.3-1, Item 19, " Automatic Actuation Logic and Actuation Relays," (2)
Tabla 4.3-2, Item la, " Safety Injection - Manual Initiation," and (3) Table 4.3-2, Item Ib, " Safety Injection - Automatic Actuation Logic and Actuation Relays."
Item 19 requires the performance of an Actuation Logic Test on a monthly staggered test basis. The TS defines the actuation logic test to be the application of various simulated input combinations in conjunction with each possible interlock state and verification of the required logic output.
This test also includes a continuity check, as a minimum, of the output i
devices.
Item 19 covers the testing of all of the logic circuitry that I
produces a signal to perform a reactor trip, which would therefore include the signals generated by a manual or automatic SI.
In addition, this testing is performed on a more frequent basis than Item 16, monthly staggered versus refueling.
Item la, "SI - Manual Initir. tion," requires the performance of a TAD 0T on a l
refueling basis.
This tast verifies the operability of the manual SI pushbuttons in the control room through to the initiation of SI, as well as, a reactor tr ip.
Item lb, "SI - Automatic Actuation Logic and Actuation Relays,"
requires the performance of an actuation logic test on a monthly staggered basis.
This test covers the testing of all of the logic circuitry that produces a signal to initiate a safety injection, which would therefore include the signals generated by the manual SI pushbuttons, low pressurizer j
pressure, low steamline pressure, and high containment pressure.
The NRC staff concludes that removal of the tests required by line item 16 in TS Tables 3.3.1 and 4.3.1 will not impact overall testing of ESF or RTS instrumentation logics. The staff finds that the tests are duplicated by other RTS and ESF Actuation System Instrumentation Surveillance Requirements.
The change is therefore acceptable.
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The licenree proposed two changes to the plant's TS.
The first change relocates the TS requirements for the containment purge exhaust and supply valves from the radiation monitoring instrumentation tables to the ESF actuation system tables. This change resulted in the transfer of previously l
approved data from one table to another.
The second proposed change removes l
line item 16, SI Input from ESF, from TS Tables 3.3-1 and 4.3-1.
The NRC l
staff agrees that the tests required by Item 16, "SI Input from ESF," are in i
fact duplicated by other RTS and ESF Actuation System Instrumentation j
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i Surveillance Requirements. The removal of line item 16 from Tables 4.3-1 and 3.3-1 has no impact on the overall testing of ESF or RTS instrumentation logics.
In conclusion, the NRC staff reviewed the proposed changes and finds j
them to be acceptable.
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3.0 STATE CONSULTATION
In accordance with the Commiss'c 4 regulations, the Connecticut State l
official was notified of the proposed issuance of the amendment.
The State l
official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
k The amendment changes a requirement with respect to installation or use of a i
facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements.
The NRC staff has determined
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that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released j
offsite, and trat there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a j
proposed finding that the amendment involves no significant hazards
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consideration, and there has been no public comment on such finding (60 FR 62494 dated December 6, 1995). Accordingly, the amendment meets the i
eligibility criteria for categorical exclusion set forth in 10 CFR i
51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Cor.tributor:
S. Wittenburg Date: June 27, 1996 l
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