ML19350A382
| ML19350A382 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 03/02/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19350A381 | List: |
| References | |
| NUDOCS 8103130671 | |
| Download: ML19350A382 (3) | |
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SAFETY EVALUATION BY THE OFFICE OF flVCLEAR REACTOR :EGULATI0ft SUPPORTING Af1E' 0 MENT NO. 2 TO LICENSE NO. DPR-22 NORTHERN STATES POWER COMPANY DOCKET NO. 50-263 MONTICELLO NUCLEAR GENERATING PLANT 1.0 Introduction By letter dated December 12, 1980, Northern States Power Company (the licensee) requested changes to the Technical Specifications (Appendix A) appended to Facility Operating License No. DPR-22 for the 11onticello Nuclear Generating Plant. The requested changes would incorporate certain of the TMI-2 Lessons Learned Category "A" requirements into the Monticello Technical Specifications. The licensee's request is in direct response to the NRC staff's letter of July 2,1980.
2.0 Backcround Information By our letter dated September 13, 1979, we issued to all operating nuclear power plants requirements established as a result of our review of the Three Mile Island Unit 2 accident. Certain of these requirements, designated Lessens Learned Category "A" requirements, were to have been completed by the licensee prior to any operation subsequent to January 1,1980. Our evaluation of the licensee's compliance with these Category "A" items was attached to our letter to Northern States Power Company dated March 21, 1980.
In order to provide reasonable assurance that operating reactor facilities are maintained within the limits determined acceptable following the implemen-tation of the TMI-2 Lessons Learned Category "A" items, we requested that licensees amend their Technical Specifications to incorporate additional Limiting Conditions of Operation and Surveillance Requirements, as appropriate.
This request was transmitted to all licensees on July 2, 1980.
Included therein were model specifications that we had determined to be acceptable.
The licensee's application is in direct response to our request.
- Finally, additions to the table of hydraulic snubbers were made as part of the Mark I Containment Long Term Program.
Each of the issues identified by the NRC staff and the licensee's response is discussed in the Evaluation below.
3.0 Evaluation 1.
Emercency Power Sunnly/Inadecuate Core Coolina As applicable to Boiling L'ater Reactors (BWRs), we indicated that water level instrumentation is irportant to post accident monitoring and that surveillance of this instrumentation should be perforr.ed. The licensee 8103130(sN, k
. has provided (Tables 3.14.1 and 4.14.1) Technical Specifications to include reactor vessel water level instru entation. These specifica-tions provide ACTION statenents for inoperable channels. Surveillance requirements for sensor checks and calibration are also included. The frequency of surveillance meets our guidelines. Based on this review, we find the licensee's proposal acceptable.
2.
Valve position Indication Our requirement for installation of a reliable position indicating system for relief and safety valves was based on the need to provide the operator with a diagnostic aid to reduce the ambiguity between indications that.
night indicate either an open relief / safety valve or a small line break.
Such a system need not be safety grade provided that backup methods of determining valve position are available.
The licensee's request would add the primary indicating system (pressure switches) and secondary indicating system (thermocouples) for the safety relief valves to the specifications. The Monticello primary relief system employs only safety relief valves. Actions have been specified for the condition of inoperability of both primary and secon-dary detector channels and to provide for torus temperature monitoring in event of the inoperability of both the primary and secondary detec-tors. Additionally, surveillance requirements have been included which r.eet our guidelines.
Based on our review, we find the licensee's proposed changes satisfy our guidelines and are acceptable.
3.
Containment Isolation Our request indicated that the specifications should include a Table of Containment Isolation Valves which reflect the diverse isolation signal requirement of this Lessons Learned issue. The licensee has modified the containnent isolation system so that diverse parameters will be sensed to ensure automatic isolation of non-essential systems under postulated accident conditions. We have reviewed this system in our Lessons Learned Category "A" Safety Evaluatien dated March 21, 1980.
The modification is such that it does not result in the automatic loss of containment isolation after the containment isolation signal is reset.
Reopening of containment isolation valves would require deliberate operator action. The existing Technical Specifications and the Technical Specifications subniitted by the licensee (Tables 3.2-1 and 3.7-1) list the affected valves by isolation group and the diverse signals sensed to initiate containment isolation of each valve group. Table 4.2-1 of the Monticello Appendix "A" Technical Specifications has been mod-ified to include surveillance requirements.
- We have reviewed the existing Technical Specifications and the modifica-tions to the Monticello Technical Specifications agreed to by the licensee and have determined that these specifications satisfy our requirements and are, therefore, acceptable.
4.
Our request indicated that the Technical Specifications related to minimum shift manning should be revised to reflect the addition of an STA. The STA function includes both accident and operating experience assessment.
The licensee proposed the addition of an STA to the minimum shift composition and the specific qualifications of the individual.
These qualifications state that the STA shall have a bachelors degree or equivalent in a scientific or engineering descipline with specific training in plant design, and response and analysis of the plant for transients and accidents. Since our position does not require degreed STAS until January 1,1981, the licensee requested that the effective date for the STA requirecent be delayed until that tir.e.
Based on our review, we find that the licensee's submittal satisfies our requirements and is acceptable.
5.
Integrity of Systems Outside Containment Our letter dated July 2,1980, indicated that the license should be a, ended by adding license conditions related to the Systems Integrity Measurenents Program.
This condition would require the licensee to implement a program to reduce leakage from systems outside containment that would or could contain highly radioactive fluids during a serious transient or accident to as low as practical levels.
The licensee instead inccrporated such requirements into Section 6.5 of the Monticello Technical Specifications. This program for leakage reduction includes, provisions establishing preventive maintenance and periodic visual inspection requirements and for periodic systems leak requirements and thus satisfies our requirements.
6.
Iodine Mcnitoring 0;r letter dated July 2, 1980 indicated that the license should be amended by adding license conditions related to Improved Iodine Measure-ments capability.
This enndition would require the licensee to implement a program which will ensure the capability to accurately determine the airborne iodine concentration in vital areas under accident conditions.