United States Nuclear Regulatory Commission - Protecting People and the Environment

Follow-up Actions Resulting From The NRC Staff Reviews Regarding The TMI-2 Accident (Generic Letter 79-51)



GL79051 

                               UNITED STATES 
                       NUCLEAR REGULATORY COMMISSION 
                          WASHINGTON. D. C. 20555 

                              October 10,1979 

              (TO ALL LICENSEES OF PLANTS UNDER CONSTRUCTION) 

Gentlemen: 

SUBJECT:  FOLLOWUP ACTIONS RESULTING FROM THE NRC STAFF REVIEWS REGARDING 
          THE THREE MILE ISLAND UNIT 2 ACCIDENT 

Over the past several months following the Three Mile Island accident, the 
NRC staff has been conducting an intensive review of the design and 
operational aspects of nuclear power plants and the emergency procedures for
coping with potential accidents. The purpose of these efforts was to 
identify measures that should be taken in the short-term to reduce the 
likelihood of such accidents and to improve the emergency preparedness in 
responding to such events. To carry out this review, efforts within NRR were 
established in four areas: (a) licensee emergency preparedness, (b) operator 
licensing, (c) bulletins and orders followup (primarily in the areas of 
auxiliary feedwater systems reliability; loss of feedwater and small break 
loss-of-coolant accident analysis; emergency operating guidelines and 
procedures) and (d) Short-Term Lessons Learned. 

The purpose of this letter is to provide for planning and guidance purposes 
the NRR staff position on the status and applicability of the results of 
these efforts to plants under construction. The Commission may add to or 
modify these staff positions after reviewing them. Additional staff require-
ments may be developed as NRR's Lessons Learned Task Force completes its 
long-term recommendations. Several other investigations, including the 
Presidential Commission and NRC's Special Inquiry Group, can be expected to 
lead to additional requirements. 
     
     Lessons Learned Task Force Report 

     The principal element of the staff activities listed above is contained
     in the report titled, "TMI-2 Lessons Learned Task Force Status Report 
     and Short-Term Recommendations" (NUREG-0573), a copy of which was 
     previously sent to you. The Task Force report contains a set of 
     recommendations to be implemented in two stages over the next 16 months
     on operating plants and pending operating license applications. The 
     Task Force recommended 20 licensing requirements and three rulemaking 
     matters in 12 broad areas. 
     
     The Advisory Committee on Reactor Safeguards has completed its review 
     of the Task Force report. The several public meetings of the ACRS 
     subcommittee on TMI-2 and the public meeting of the full committee on 
     August 9 provided 
.

                                  - 2 -

                                                           October 10, 1979 

     an opportunity for the presentation and discussion of public comments 
     on the report. The ACRS letter of August 13, 1979 to Chairman Hendrie 
     states that the Committee agrees with the intent and substance of all 
     the Task Force recommendations, except four upon which the Committee 
     offered constructive comments to achieve the same objectives 
     articulated by the Task Force. A copy of the ACRS letter is provided as 
     Enclosure 1. 

     After evaluating all comments received, we have concluded that the 
     following actions are appropriate for plants under construction. 

     (a)  The staff will be proposing a new rule on a Limiting Condition of 
          Operation to require plant shutdown for certain human or 
          procedural errors, particularly those which are repetitive in 
          nature. As such, no action is required on your part at this time. 
          
     (b)  At the present time we are delaying efforts regarding proposed 
          rulemaking on both the inerting requirements for Mark I and II BWR
          containments, and the requirement regarding hydrogen recombiner 
          capability; accordingly, no action is required on your part at 
          this time. 

     (c)  The ACRS comments on the shift technical advisor have resulted in 
          our reassessment of the possible means of achieving the two 
          functions which the Task Force intended to provide by this 
          requirement. The two functions are accident assessment and 
          operating experience assessment by people onsite with engineering 
          competence and certain other characteristics. We have concluded 
          that the shift technical advisor concept is the preferable 
          short-term method of supplying these functions. We have also 
          concluded that some flexibility in implementation may yield the 
          desired results if there is management innovation by individual 
          licensees. We have prepared a statement of functional 
          characteristics for the shift technical advisor that will be used 
          by the staff in the review of any alternatives proposed by 
          applicants for operating licenses. A copy is provided as Enclosure
          2. The Commission is considering whether or not additional 
          qualifications should be required for this individual. 

     (d)  Three additional instrumentation requirements for short-term 
          action were developed during the ACRS review of NUREG-0578. These 
          items relate to containment pressure, containment water level and 
          containment hydrogen monitors designed to follow the course of an 
          accident.  Descriptions of these items are provided in Enclosure 
          3. 
          
     (e)  An additional requirement following issuance of NUREG-0578, which 
          concerned a remotely operable high point vent for gas from the 
          reactor coolant system, was developed. A description of this 
          requirement is provided in Enclosure 4. 
.

                                 - 3 -                    October 10, 1979 

     (f)  The Lessons Learned- Task Force has compiled a set of errata and 
          clarifying comments for NUREG-0578. It is provided as Enclosure 5.

Following our review of the proposed Task Force recommendations, ACRS review
and comments received, we have concluded that all licensees of plants under 
construction should implement the actions contained in NUREG-0578, as 
modified and/or supplemented by items (a) through (f) above. Therefore, we 
suggest that you also consider these requirements in developing your final 
plant design and procedures, and include a description of your actions in 
this regard in your application for an operating license. An implementation 
schedule for operating plants and pending operating license applications is 
provided in Enclosure 6 for information. The implementation dates for the 
Commission rulemaking actions and those deferred actions, identified above, 
will be established later. 

Other Review Areas 

Enclosure 7 outlines the requirements developed to date resulting from the 
staff's Emergency Preparedness Studies. Enclosure 8, which applies to 
operating plants and pending operating license applications, provides the 
implementation schedules for the emergency preparedness recommendations 
which, you will note, includes three of the Lessons Learned topics. The 
staff position is that you should comply with each of the recommendations of
Enclosure 7. Therefore, we suggest that you also consider these requirements
in developing your final plant design and procedures, and include a 
description of your actions in this regard in your application for an 
operating license. Further, the Commission has initiated a rulemaking 
procedure, now scheduled for completion in January 1980 in the area of 
Emergency Planning and Preparedness. Additional requirements are to be 
expected when rulemaking is completed and some modifications to the 
emergency preparedness requirements contained in this letter may be 
necessary. 

Enclosure 9 outlines the staff recommendations concerning improvements in 
the area of operator training which are provided for your information. These 
recommendations are undergoing Commission review and are expected to be 
adopted as requirements in the near future. Further Commission review in the 
areas of operator training and qualification can be expected to result in 
substantial additional requirements. 

A number of other related actions on your facility may have been initiated 
under the direction of the NRR Bulletins and Orders Task Group. Each 
licensee will receive additional guidance from this group, particularly 
related to auxiliary feedwater systems and small break LOCAs, in the near 
future. Your activities should continue in these areas, as all the mentioned 
activities are meant to complement one another. 
.

                                 - 4 -                   October 10, 1979 

The measures discussed above represent a set of requirements that the staff 
has concluded should be implemented at this time. As stated earlier, other 
requirements may follow in the future. The procedures for Commission review 
of TMI-related issues prior to the issuance of operating licenses have not 
yet been established. The Commission is considering several alternatives, 
and you will be notified when a decision is made in this matter. 

If you have any questions regarding these actions, please contact the NRC 
Project Manager for your facility. 

                                   Sincerely, 



                                   Domenic B. Vassallo, Acting Director 
                                   Division of Project Management 

Enclosures:
1.   ACRS Ltr: Carbon to Hendrie dtd 8/13/79 
2.   Alternatives to Shift Technical Advisor 
3.   Instrumentation to Monitor Containment Conditions 
4.   Installation of Remotely Operated High Point Vents 
          in the Reactor Coolant System 
5.   NUREG-0578 Errata 
6.   Implementation Schedule 
7.   Requirements for Improving Emergency Preparedness 
8.   Emergency Preparedness Improvements - Implementation Schedule 
9.   Improvements in Operator Training
Page Last Reviewed/Updated Wednesday, May 22, 2013